Key Notes

Key Notes on Plastic Surgery Adrian Richards MBBS, MSc, FRCS (Plast) Plastic and Cosmetic Surgeon Aurora Clinics Princes Risborough UK Hywel Dafydd MB BChir, MA, MSc, FRCS (Plast) Specialty Registrar The Welsh Centre for Burns and Plastic Surgery Morriston Hospital Swansea UK SECOND EDITION F O R E W O R D B Y P R O F E S S O R F U-C H A N W E I This edition first published 2015 © 2015 by John Wiley & Sons, Ltd © 2002 by Blackwell Science Ltd Registered office: John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial offices: 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 111 River Street, Hoboken, NJ 07030-5774, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. 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No warranty may be created or extended by any promotional statements for this work. Neither the publisher nor the author shall be liable for any damages arising herefrom. Library of Congress Cataloging-in-Publication Data Richards, Adrian M., author. Key notes on plastic surgery / Adrian Richards, Hywel Dafydd ; foreword by professor Fu-Chan Wei. – Second edition. 1 online resource. Includes bibliographical references and index. Description based on print version record and CIP data provided by publisher; resource not viewed. ISBN 978-1-118-75686-7 (Adobe PDF) – ISBN 978-1-118-75699-7 (ePub) – ISBN 978-1-4443-3434-0 (pbk.) I. Dafydd, Hywel, author. II. Title. [DNLM: 1. Surgery, Plastic. WO 600] RD119 617.9′ 52 – dc23 2014033321 A catalogue record for this book is available from the British Library. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Cover image: © iStock.com/youngvet Cover design by Andy Meaden Set in 9.5/12pt Meridien by Laserwords Private Limited, Chennai, India 1 2015 Contents Foreword iv Preface v Dedications vi Acknowledgements vi Abbreviations vii 1 General Principles 2 Skin and Soft Tissue Lesions 3 The Head and Neck 133 4 The Breast and Chest Wall 264 5 The Upper Limb 309 6 The Lower Limb 422 7 The Trunk and Urogenital System 459 8 Burns 490 9 Aesthetic Surgery 530 Ethics, the Law and Statistics 591 Index 605 10 1 80 iii Foreword This second edition of Key Notes on Plastic Surgery distills the breadth and depth of the entire specialty into a compact format. Clear, concise, accurate and accessible – that is what the trainee desires when refreshing their memory of conditions during clinic, of reconstructive algorithms before operating, and of the entire syllabus when preparing for plastic surgery board examinations. Key Notes on Plastic Surgery fulfils this niche admirably. A consistent balance has been struck between prose and bullet points throughout the book. Key Notes on Plastic Surgery fosters understanding, facilitates the commitment of information to memory, and provides structure to ease the recall of facts and principles. One can rapidly glean key information with a glance at the page and yet solidify an understanding with a few minutes’ read. The textual formatting and presentation of information is where this book particularly shines. Key Notes on Plastic Surgery will be embraced as a trusted companion by trainees all over the world as they progress through training and sit for their board examinations. And when they become established plastic surgeons, Key Notes on Plastic Surgery will take pride of place on their bookshelves as a reliable quick reference handbook for teaching the next generation. I highly recommend Key Notes on Plastic Surgery to all aspiring, training and established plastic surgeons worldwide. Fu-Chan Wei, MD, FACS Distinguished Chair Professor Chang Gung University Medical College Taipei, Taiwan Academician Academia Sinica Taiwan iv Preface Hywel Dafydd has updated and improved the first edition of Key Notes on Plastic Surgery. He has worked tirelessly to include new and better diagrams and improve the content whilst maintaining the book’s ethos – to succinctly communicate the essentials of Plastic Surgery. We hope you enjoy the book and find it helpful in making you a better Plastic Surgeon. Adrian Richards The first edition of Key Notes has proved to be exceptionally popular for over a decade. Accessible, informative and succinct, it became the preferred handbook for innumerable plastic surgery trainees. It was typeset with enough ‘white space’ to accommodate trainees’ notes and sketches as they approached their final plastic surgery examination. Nevertheless, an update was much-needed: the field of plastic surgery has moved on apace and a detailed British plastic surgery syllabus was introduced. The material of the first edition has been updated, rewritten and expanded with several new sections to reflect this. In addition, a new chapter is provided: ‘Ethics and the law’. The number of diagrams has more than doubled, which should help with learning the ‘essentials’, such as cleft lip repair and eyelid anatomy. Key Notes is now more complete and, although necessarily larger, remains true to the format and style of the first edition. We hope that Key Notes continues to be useful to plastic surgeons worldwide. Hywel Dafydd v Dedications AR – To my Family, Helena, Josie, Ciara, Alfie and Ned. HD – For Jenny and Ioan. Acknowledgements As any Plastic Surgeon will tell you, the training and practice of the speciality takes dedication and hard work. Writing a book in your free time adds to this and requires patience and support from your family. For this reason I would like to thank my family Helena, Josie, Ciara, Alfie and Ned for their constant support. I would also like to thank my surgical mentors of whom there were many – in particular Brent Tanner and Michael Klaassen. Adrian Richards I would like to thank my wife Jenny and my son Ioan for their love and patience. Jenny also helped edit final drafts for brevity. Thank you Per Hall for inspiring me to become a plastic surgeon. Thanks to those who have trained me over the years in Cambridge, Wellington, Leicester, Birmingham, Coventry, Swansea, Taipei, and Auckland. Special thanks to Sarah Hemington-Gorse, Ian Josty, Dai Nguyen, Nick Wilson Jones, Tom Potokar, Peter Drew, Leong Hiew, Hamish Laing, Dean Boyce, Max Murison and Ian Pallister, who spent hours proofreading early drafts. I am also grateful to Rhidian Dafydd LLB, Karen Wong and Chris Wallace, who checked much of the text for accuracy. Tom Macleod has been a constant source of support and encouragement, and did a great deal of preparatory work on many of the chapters. The book could not have been written without the staff of Morriston Hospital’s library. They sourced over 600 references from three centuries without as much as a grumble: thank you Anne, Sue, Rita and Lisa. Hywel Dafydd vi Abbreviations 5-FU ABC ABPI AC ACPA ACR ADH ADM ADM AER AFX AICAP AIDS AIN AJCC AK ALCL ALH ALS ALT ANOVA AO AP APB APC APL APR APTT ARDS ASIS ASSH ATG ATLS AVA AVM AVN BAAPS BAHA 5-fluorouracil Acinetobacter baumanii-calcoaceticus ankle brachial pressure index alternating current anti-citrullinated protein antibody American College of Rheumatology atypical ductal hyperplasia abductor digiti minimi acellular dermal matrix apical ectodermal ridge atypical fibroxanthoma anterior intercostal artery perforator (flap) acquired immune deficiency syndrome anal intraepithelial neoplasia American Joint Committee on Cancer actinic keratosis anaplastic large T-cell lymphoma atypical lobular hyperplasia anti-lymphocyte serum anterolateral thigh (flap) analysis of variance Arbeitsgemeinschaft für Osteosynthesefragen anteroposterior abductor pollicis brevis antigen presenting cell abductor pollicis longus abdomino-perineal resection activated partial thromboplastin time adult respiratory distress syndrome anterior superior iliac spine American Society for Surgery of the Hand anti-thymoglobulin Advanced Trauma Life Support arteriovenous anastomosis arteriovenous malformation avascular necrosis British Association of Aesthetic Plastic Surgeons bone-anchored hearing aid vii viii Abbreviations BAPRAS BAPS BCC BDD BEAM BMI BMP BOA BPD BRAF BRBN BSA BSSH BXO cAMP CCNE CEA CFNG CI CIN CL CM CMCJ CMN CNS CO COX CP CPAP CPR CRP CRPS CSAG CSF CT CTA CTLA CTS CVP CVS DASH DBD DC DCIA British Association of Plastic, Reconstructive and Aesthetic Surgeons British Association of Plastic Surgeons basal cell carcinoma body dysmorphic disorder bulbar elongation and anastomotic meatoplasty body mass index bone morphogenetic protein British Orthopaedic Association biliopancreatic diversion B-Raf serine/threonine-protein kinase blue rubber bleb naevus (syndrome) body surface area British Society for Surgery of the Hand balanitis xerotica obliterans cyclic adenosine monophosphate Comité Consultatif National d’Ethique cultured epithelial autograft cross facial nerve grafting cranial index cervical intraepithelial neoplasia cleft lip capillary malformation carpometacarpal joint congenital melanocytic naevus central nervous system carbon monoxide cyclooxygenase cleft palate continuous positive airways pressure cardiopulmonary resuscitation C-reactive protein complex regional pain syndrome Clinical Standards Advisory Group cerebrospinal fluid computed tomography composite tissue allotransplantation cytotoxic T-lymphocyte antigen carpal tunnel syndrome central venous pressure cardiovascular system Disabilities of the Arm, Shoulder and Hand dermolytic bullous dermatitis direct current deep circumflex iliac artery Abbreviations DCIS DD DEXA DFAP DFSP DICAP DIEA DIEP DIPJ DIY DMARD DNA DOPA DOT DRUJ DTH EAST EBV ECG ECRB ECRL ECU EDC EDM EGF EIP ELND EEMG ELD EMG EMLA ENT EO EPB EPL EPUAP ER ERK ESBL ESR EULAR FAMM FAMM FBC ductal carcinoma in situ Dupuytren’s disease dual-energy X-ray absorptiometry deep femoral artery perforator (flap) dermatofibrosarcoma protuberans dorsal intercostal artery perforator (flap) deep inferior epigastric artery deep inferior epigastric perforator (flap) distal interphalangeal joint do it yourself disease-modifying antirheumatic drug deoxyribonucleic acid dihydroxyphenylalanine double-opposing tab distal radio-ulnar joint delayed type hypersensitivity elevated arm stress test Epstein-Barr virus electrocardiogram extensor carpi radialis brevis extensor carpi radialis longus extensor carpi ulnaris extensor digitorum communis extensor digiti minimi epidermal growth factor extensor indicis proprius elective lymph node dissection evoked electromyography extended latissimus dorsi (flap) electromyography eutetic mixture of local anaesthetic ear, nose and throat external oblique extensor pollicis brevis extensor pollicis longus European Pressure Ulcer Advisory Panel oestrogen receptor extracellular-signal-regulated kinase extended-spectrum beta-lactamase erythrocyte sedimentation rate European League Against Rheumatism facial artery musculomucosal (flap) familial atypical mole and melanoma (syndrome) full blood count ix x Abbreviations FCR FCU FDA FDG FDM FDMA FDP FDS FFMT FFP FGF FGFR FIESTA FISH FLAIR FNA FNAC FPB FPL GAG GAS GCS GI GLUT1 GMC GP Hb HER HES HF HFS HIT HIV HLA HMB-45 hMLH1 hMSH2 HPV HRT HTA HU ICAP ICD ICG flexor carpi radialis flexor carpi ulnaris Food and Drug Administration fluorodeoxyglucose flexor digiti minimi first dorsal metacarpal artery (flap) flexor digitorum profundus flexor digitorum superficialis free functioning muscle transfer fresh frozen plasma fibroblast growth factor fibroblast growth factor receptor fast imaging employing steady-state acquisition fluorescence in situ hybridisation fluid attenuated inversion recovery fine needle aspiration fine needle aspiration cytology flexor pollicis brevis flexor pollicis longus glycosaminoglycan group A Streptococcus Glasgow coma scale gastro-intestinal glucose transporter 1 General Medical Council general practitioner haemoglobin human epidermal growth factor receptor hydroxyethyl starch hydrofluoric acid Hannover Fracture Scale heparin-induced thrombocytopenia human immunodeficiency virus human leukocyte antigen human melanoma black 45 human mutL homolog 1 (gene) human mutS homolog 2 (gene) human papilloma virus hormone replacement therapy Human Tissue Authority Hounsfield units intercostal artery perforator (flap) intercanthal distance indocyanine green Abbreviations ICP ICU IDDM IFN IFSSH IGA IGAM IGAP IHC IJV IL IMF IMF IMNAS INR IO IOD IPJ IPL IRG ISSVA ITL ITU IV IVF KA KTP KTS LA LASER LCIS LD LDH LDMF LEAP LHRH LICAP LISN LM LM LME LMM LMWH LRTI intracranial pressure intensive care unit insulin dependent diabetes mellitus interferon International Federation of Societies for Surgery of the Hand inferior gluteal artery inferior gluteal artery myocutaneous (flap) inferior gluteal artery perforator (flap) immunohistochemistry internal jugular vein interleukin inframammary fold intermaxillary fixation Institute of Medicine of the National Academy of Science international normalised ratio internal oblique interorbital distance interphalangeal joint intense pulsed light Independent Review Group International Society for the Study of Vascular Anomalies inferior temporal line intensive therapy unit intravenous in vitro fertilisation keratoacanthoma potassium titanyl phosphate Klippel-Trénaunay syndrome local anaesthesia light amplification by stimulated emission of radiation lobular carcinoma in situ latissimus dorsi lactate dehydrogenase latissimus dorsi miniflap Lower Extremity Assessment Project luteinising hormone releasing hormone lateral intercostal artery perforator (flap) lobular in situ neoplasia lentigo maligna lymphatic malformation line of maximum extensibility lentigo maligna melanoma low-molecular-weight heparin ligament reconstruction and tendon interposition xi xii Abbreviations LSI LSMDT MACS MAGPI MAL MAPK MARIA MART MCA MCC MCPJ MDT MEK MESS MFH MHC MHRA MIP MLD MM MMF MODS MPNST MRC MRI MRKH MRND MRSA MS MSG MSH MSLT MSU MSX2 mTOR MTPJ MTT NAC NAI NASHA NCS NF NG NHS Limb Salvage Index local skin cancer multidisciplinary team Minimal Access Cranial Suspension meatal advancement and glanuloplasty incorporated methyl aminolevulinate mitogen-activated protein kinase Multistatic Array Processing for Radiowave Image Acquisition melanoma antigen recognised by T cells Mental Capacity Act Merkel cell carcinoma metacarpophalangeal joint multidisciplinary team mitogen/extracellular signal-regulated kinase Mangled Extremity Severity Score malignant fibrous histiocytoma major histocompatibility complex Medicines and Healthcare Products Regulatory Agency megameatus intact prepuce manual lymphatic drainage malignant melanoma mandibulomaxillary fixation multiple organ dysfunction syndrome malignant peripheral nerve sheath tumour Medical Research Council magnetic resonance imaging Mayer–Rokitansky–Küster–Hauser (syndrome) modified radical neck dissection methicillin resistant Staphylococcus aureus muscle sparing Melanoma Study Group melanocyte-stimulating hormone Multicenter Selective Lymphadenectomy Trial monosodium urate msh homeobox 2 (gene) mammalian target of rapamycin metatarsophalangeal joint malignant triton tumour nipple-areola complex non-accidental injury non-animal stabilised hyaluronic acid nerve conduction studies neurofibromatosis nasogastric National Health Service Abbreviations NICH NK NOE NPA NPI NPUAP NPWT NSAID NSM NVB OA OGS OM OP ORIF PA PAL PABA PAF PCNA PDE PDE PDGF PDS PDT PEEP PET PET PHA PIN PIP PIPJ PL PL PMMA PMN POSI PR PRPC PRS PSI PSIS PT PT noninvoluting congenital haemangioma natural killer (cell) nasoorbitoethmoidal nasopharyngeal airway Nottingham Prognostic Index National Pressure Ulcer Advisory Panel negative pressure wound therapy non-steroidal anti-inflammatory drug nipple sparing mastectomy neurovascular bundle osteoarthritis orthognathic surgery osteomyelitis opponens pollicis open reduction and internal fixation posteroanterior power-assisted liposuction para-amino benzoic acid platelet activating factor proliferating cell nuclear antigen (gene) phosphodiesterase Photodynamic Eye platelet-derived growth factor polydioxanone sulphate photodynamic therapy positive end-expiratory pressure polyethylene terephthalate positron emission tomography progressive hemifacial atrophy posterior interosseous nerve Poly Implant Prothèse proximal interphalangeal joint palmaris longus phospholipid polymethylmethacrylate polymorphonuclear neutrophils position of safe immobilisation progesterone receptor platelet-rich plasma concentrate Pierre Robin sequence Predictive Salvage Index posterior superior iliac spine prothrombin time pronator teres xiii xiv Abbreviations PTCH PTEN PTFE RA RA RAPD RCT REE RF RFAL RFF RICH RND ROOF RSTL SAL SAN SCAP SCC SCIA SCM SEPS SFS SGAP SHH SIEA SIRS SJS SLE SLL SLNB SMAS SNAP SNAP SND SNUC SOOF SPAIR SRY SSD SSM SSSS STIR STL patched (gene) phosphatase and tensin homolog (gene) polytetrafluoroethylene rectus abdominis rheumatoid arthritis relative afferent pupillary defect randomised controlled trial resting energy expenditure rheumatoid factor radiofrequency assisted liposuction radial forearm flap rapidly involuting congenital haemangioma radical neck dissection retro-orbicularis oculi fat (pad) relaxed skin tension line suction-assisted liposuction spinal accessory nerve syringocystadenoma papilliferum squamous cell carcinoma superficial circumflex iliac artery sternocleidomastoid subfascial endoscopic perforating vein surgery superficial fascial system superior gluteal artery perforator (flap) sonic hedgehog superficial inferior epigastric artery (flap) systemic inflammatory response syndrome Stevens-Johnson syndrome systemic lupus erythematosus scapholunate ligament sentinel lymph node biopsy superficial muscular aponeurotic system sensory nerve action potential synaptosomal-associated protein selective neck dissection sinonasal undifferentiated carcinoma suborbicularis oculi fat (pad) short scar periareolar inferior pedicle reduction sex-determining region of the Y chromosome silver sulfadiazine skin sparing mastectomy staphylococcal scalded skin syndrome short T1 inversion recovery superior temporal line Abbreviations STS STT TA TAM TAR TB TBSA TCA TDA TDAP TED TEN TF TFL TGF TIMP TIP TMJ TNF TNM TNMG TOS t-PA TPN TRAM TRT TSS TSST TUG TWIST UAL UCL UK USA USP UV USS VAIN VASER VCA VEGF VEGFR VF VIN soft tissue sarcoma scaphotrapezium-trapezoid transversus abdominis total active motion thrombocytopenia – absent radius (syndrome) tubercle bacillus total body surface area trichloroacetic acid toluene diamine thoracodorsal artery perforator thromboembolic device toxic epidermal necrolysis tissue factor tensor fasciae latae transforming growth factor tissue inhibitor of metalloproteinase tubularised incised plate temporomandibular joint tumour necrosis factor tumour, nodes, metastasis tumour, nodes, metastasis, grade thoracic outlet syndrome tissue plasminogen activator total parenteral nutrition transverse rectus abdominis myocutaneous (flap) thermal relaxation time toxic shock syndrome toxic shock syndrome toxin transverse upper gracilis twist family basic helix-loop-helix transcription factor (gene) ultrasound-assisted liposuction ulnar collateral ligament United Kingdom United States of America United States Pharmacopeia ultraviolet ultrasound scan vaginal intraepithelial neoplasia Vibration Amplification of Sound Energy at Resonance vascularised composite allotransplantation vascular endothelial growth factor vascular endothelial growth factor receptor ventricular fibrillation vulval intraepithelial neoplasia xv xvi Abbreviations VM VMCM VPI VRAM VRE vWF WHO WLE WNT7A XP YAG ZF ZM ZPA venous malformation multiple cutaneous and mucosal venous malformations velopharyngeal insufficiency vertical rectus abdominis myocutaneous (flap) vancomycin resistant Enterococcus von Willebrand factor World Health Organisation wide local excision wingless-type MMTV integration site family, member 7A xeroderma pigmentosa yttrium aluminium garnet zygomaticofrontal zygomaticomaxillary zone of polarising activity CHAPTER 1 General Principles CHAPTER CONTENTS Embryology, structure and function of the skin, 1 Blood supply to the skin, 5 Classification of flaps, 9 Geometry of local flaps, 13 Wound healing and skin grafts, 22 Bone healing and bone grafts, 31 Cartilage healing and cartilage grafts, 35 Nerve healing and nerve grafts, 36 Tendon healing, 41 Transplantation, 42 Tissue engineering, 47 Alloplastic implantation, 48 Wound dressings, 53 Sutures and suturing, 55 Tissue expansion, 57 Lasers, 61 Local anaesthesia, 65 Microsurgery, 69 Haemostasis and thrombosis, 74 Further reading, 77 Embryology, structure and function of the skin • Skin differentiates from ectoderm and mesoderm during the 4th week. • Skin gives rise to: ∘ Teeth and hair follicles, derived from epidermis and dermis ∘ Fingernails and toenails, derived from epidermis only. • Hair follicles, sebaceous glands, sweat glands, apocrine glands and mammary glands are ‘epidermal appendages’ because they develop as ingrowths of epidermis into dermis. • Functions of skin: 1 Physical protection 2 Protection against UV light 3 Protection against microbiological invasion 4 Prevention of fluid loss Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 1 2 Chapter 1 5 Regulation of body temperature 6 Sensation 7 Immunological surveillance. Epidermis Papillary dermis Reticular dermis Subcutaneous tissue Arrector pili muscle Sebaceous gland Hair bulb Eccrine sweat gland The epidermis • Composed of stratified squamous epithelium. • Derived from ectoderm. • Epidermal cells undergo keratinisation – their cytoplasm is replaced with keratin as the cell dies and becomes more superficial. • Rete ridges are epidermal thickenings that extend downward between dermal papillae. • Epidermis is composed of these five layers, from deep to superficial: 1 Stratum germinativum ∘ Also known as the basal layer. ∘ Cells within this layer have cytoplasmic projections (hemidesmosomes), which firmly link them to the underlying basal lamina. ∘ The only actively proliferating layer of skin. ∘ Stratum germinativum also contains melanocytes. 2 Stratum spinosum ∘ Also known as the prickle cell layer. ∘ Contains large keratinocytes, which synthesise cytokeratin. ∘ Cytokeratin accumulates in aggregates called tonofibrils. ∘ Bundles of tonofibrils converge into numerous desmosomes (prickles), forming strong intercellular contacts. 3 Stratum granulosum ∘ Contains mature keratinocytes, with cytoplasmic granules of keratohyalin. ∘ The predominant site of protein synthesis. ∘ Combination of cytokeratin tonofibrils with keratohyalin produces keratin. 4 Stratum lucidum ∘ A clear layer, only present in the thick glabrous skin of palms and feet. General Principles 3 5 Stratum corneum ∘ Contains non-viable keratinised cells, having lost their nuclei and cytoplasm. ∘ Protects against trauma. ∘ Insulates against fluid loss. ∘ Protects against bacterial invasion and mechanical stress. Cellular composition of the epidermis • Keratinocytes – the predominant cell type in the epidermis. • Langerhans cells – antigen-presenting cells (APCs) of the immune system. • Merkel cells – mechanoreceptors of neural crest origin. • Melanocytes – neural crest derivatives: ∘ Usually located in the stratum germinativum. ∘ Produce melanin packaged in melanosomes, which is delivered along dendrites to surrounding keratinocytes. ∘ Melanosomes form a cap over the nucleus of keratinocytes, protecting DNA from UV light. The dermis Accounts for 95% of the skin’s thickness. Derived from mesoderm. Papillary dermis is superficial; contains more cells and finer collagen fibres. Reticular dermis is deeper; contains fewer cells and coarser collagen fibres. It sustains and supports the epidermis. Dermis is composed of: Collagen fibres ∘ Produced by fibroblasts. ∘ Through cross-linking, are responsible for much of the skin’s strength. ∘ The normal ratio of type 1 to type 3 collagen is 5:1. 2 Elastin fibres ∘ Secreted by fibroblasts. ∘ Responsible for elastic recoil of skin. 3 Ground substance ∘ Consists of glycosaminoglycans (GAGs): hyaluronic acid, dermatan sulphate, chondroitin sulphate. ∘ GAGs are secreted by fibroblasts and become ground substance when hydrated. 4 Vascular plexus ∘ Separates the denser reticular dermis from the overlying papillary dermis. • • • • • • 1 Skin appendages Hair follicles • Each hair is composed of a medulla, a cortex and an outer cuticle. • Hair follicles consist of an inner root sheath (derived from epidermis), and an outer root sheath (derived from dermis). 4 Chapter 1 • Several sebaceous glands drain into each follicle. ∘ Drainage of the glands is aided by contraction of arrector pili muscles. • Vellus hairs are fine and downy; terminal hairs are coarse. • Hairs are either in anagen (growth), catagen (regressing), or telogen (resting) phase. ∘ <90% are in anagen, 1–2% in catagen and 10–14% in telogen at any one time. Eccrine glands • These sweat glands secrete odourless hypotonic fluid. • Present in almost all sites of the body. • Occur more frequently in the palm, sole and axilla. Apocrine glands • Located in axilla and groin. • Emit a thicker secretion than eccrine glands. • Responsible for body odour; do not function before puberty. • Modified apocrine glands are found in the external ear (ceruminous glands) and eyelid (Moll glands). • The mammary gland is a modified apocrine gland specialised for manufacture of colostrum and milk. • Hidradenitis suppurativa is a disease of apocrine glands. Sebaceous glands • Holocrine glands that drain into the pilosebaceous unit in hair-bearing skin. • They drain directly onto skin in the labia minora, penis and tarsus (meibomian glands). • Most prevalent on forehead, nose and cheek; absent from palms and soles. • Produce sebum, which contains fats and their breakdown products, wax esters and debris of dead fat-producing cells. ∘ Sebum is bactericidal to staphylococci and streptococci. • Sebaceous glands are not the sole cause of so-called sebaceous cysts. • These cysts are in fact of epidermal origin and contain all substances secreted by skin (predominantly keratin). ∘ Some maintain they should therefore be called epidermoid cysts. Types of secretion from glands • Eccrine or merocrine glands secrete opened vesicles via exocytosis. • Apocrine glands secrete by ‘membrane budding’ – pinching off part of the cytoplasm in vesicles bound by the cell’s own plasma membrane. • Holocrine gland secretions are produced within the cell, followed by rupture of the cell’s plasma membrane. Histological terms • Acanthosis: epidermal hyperplasia. • Papillomatosis: increased depth of corrugations at the dermoepidermal junction. • Hyperkeratosis: increased thickness of the keratin layer. General Principles 5 • Parakeratosis: presence of nucleated cells at the skin surface. • Pagetoid: when cells invade the upper epidermis from below. • Palisading: when cells are oriented perpendicular to a surface. Blood supply to the skin • Epidermis contains no blood vessels. • It is dependent on dermis for nutrients, supplied by diffusion. Anatomy of the circulation • Blood reaching the skin originates from named deep vessels. • These feed interconnecting vessels, which supply the vascular plexuses of fascia, subcutaneous tissue and skin. Deep vessels • Arise from the aorta and divide to form the main arterial supply to head, neck, trunk and limbs. Interconnecting vessels • The interconnecting system is composed of: ∘ Fasciocutaneous (or septocutaneous) vessels – Reach the skin directly by traversing fascial septa. – Provide the main arterial supply to skin in the limbs. • Musculocutaneous vessels ∘ Reach the skin indirectly via muscular branches from the deep system. ∘ These branches enter muscle bellies and divide into multiple perforating branches, which travel up to the skin. ∘ Provide the main arterial supply to skin of the torso. Vascular plexuses of fascia, subcutaneous tissue and skin 1 Subfascial plexus ∘ Small plexus lying on the undersurface of deep fascia. 2 Prefascial plexus ∘ Larger plexus superficial to deep fascia; prominent on the limbs. ∘ Predominantly supplied by fasciocutaneous vessels. 3 Subcutaneous plexus ∘ At the level of superficial fascia. ∘ Mainly supplied by musculocutaneous vessels. ∘ Predominant on the torso. 4 Subdermal plexus ∘ Receives blood from the underlying plexuses. ∘ The main plexus supplying blood to skin. ∘ Accounts for dermal bleeding observed in incised skin. 6 Chapter 1 5 Dermal plexus ∘ Mainly composed of arterioles. ∘ Plays an important role in thermoregulation. 6 Subepidermal plexus ∘ Contains small vessels without muscle in their walls. ∘ Predominantly nutritive and thermoregulatory function. Angiosomes • • • • • • • • An angiosome is a three-dimensional composite block of tissue supplied by a named artery. The area of skin supplied by an artery was first studied by Manchot in 1889. His work was expanded by Salmon in the 1930s, and more recently by Taylor and Palmer. The anatomical territory of an artery is the area into which the vessel ramifies before anastomosing with adjacent vessels. The dynamic territory of an artery is the area into which staining extends after intravascular infusion of fluorescein. The potential territory of an artery is the area that can be included in a flap if it is delayed. Vessels that pass between anatomical territories are called choke vessels. The transverse rectus abdominis myocutaneous (TRAM) flap illustrates the angiosome concept well: Zone 1 • Receives musculocutaneous perforators from the deep inferior epigastric artery (DIEA) and is therefore in its anatomical territory. Zones 2 and 3 • There is controversy as to which of the following zones is 2 and which is 3. • Hartrampf’s 1982 description has zone 2 across the midline and zone 3 lateral to zone 1. ∘ Holm’s 2006 study shows the opposite to be true. • Skin lateral to zone 1 is in the anatomical territory of the superficial circumflex iliac artery (SCIA). ∘ Blood has to travel through a set of choke vessels to reach it from the ipsilateral DIEA. • Skin on the contralateral side of the linea alba is in the anatomical area of the ipsilateral DIEA. ∘ It is also within the dynamic territory of the contralateral DIEA. ∘ This allows a TRAM flap to be reliably perfused based on either DIEA. Zone 4 • This lies furthest from the pedicle and is in the anatomical territory of the contralateral SCIA. • Blood passing from the pedicle to zone 4 has to cross two sets of choke vessels. • This portion of the TRAM flap has the worst blood supply and is often discarded. Arterial characteristics • Taylor made the following observations from his detailed anatomical dissections: ∘ Vessels usually travel with nerves. ∘ Vessels obey the law of equilibrium – if one is small, its neighbour will tend to be large. General Principles ∘ ∘ ∘ 7 Vessels travel from fixed to mobile tissue. Vessels have a fixed destination but varied origin. Vessel size and orientation is a product of growth. Venous characteristics • Venous networks consist of linked valvular and avalvular channels that allow equilibrium of flow and pressure. • Directional veins are valved; typically found in subcutaneous tissues of limbs or as a stellate pattern of collecting veins. • Oscillating avalvular veins allow free flow between valved channels of adjacent venous territories. ∘ They mirror and accompany choke arteries. ∘ They define the perimeter of venous territories in the same way choke arteries define arterial territories. • Superficial veins follow nerves; perforating veins follow perforating arteries. The microcirculation • Terminal arterioles are found in reticular dermis. ∘ They terminate as they enter the capillary network. • The precapillary sphincter is the last part of the arterial tree containing muscle within its wall. ∘ It is under neural control and regulates blood flow into the capillary network. • The skin’s blood supply far exceeds its nutritive requirements. • It bypasses capillary beds via arteriovenous anastomoses (AVAs) and has a primarily thermoregulatory function. ∘ AVAs connect arterioles to efferent veins. • AVAs are of two types: 1 Indirect AVAs – convoluted structures known as glomera (sing. glomus) – Densely innervated by autonomic nerves. 2 Direct AVAs – less convoluted with sparser autonomic supply. Control of blood flow • The muscular tone of vessels is controlled by: Pressure of the blood within vessels (myogenic theory) • Originally described by Bayliss, states that: ∘ Increased intraluminal pressure results in constriction of vessels. ∘ Decreased intraluminal pressure results in their dilatation. • Helps keep blood flow constant; accounts for hyperaemia on release of a tourniquet. Neural innervation • Arterioles, AVAs and precapillary sphincters are sympathetically innervated. • Increased arteriolar tone results in decreased cutaneous blood flow. • Increased precapillary sphincter tone reduces blood flow into capillary networks. • Decreased AVA tone increases non-nutritive blood flow bypassing the capillary bed. 8 Chapter 1 Humoral factors • Epinephrine, norepinephrine, serotonin, thromboxane A2 and prostaglandin F2α cause vasoconstriction. • Histamine, bradykinin and prostaglandin E1 cause vasodilatation. • Low O2 saturation, high CO2 saturation and acidosis also cause vasodilatation. Temperature • Heat causes cutaneous vasodilatation and increased flow, which predominantly bypasses capillary beds via AVAs. The delay phenomenon • Delay is any preoperative manoeuvre that results in increased flap survival. • Historical examples include Tagliacozzi’s nasal reconstruction described in the 16th century. ∘ Involves elevation of a bipedicled flap with length : breadth ratio of 2:1. ∘ The flap can be considered as two 1:1 flaps. ∘ Cotton lint is placed under the flap, preventing its reattachment. ∘ Two weeks later, one end of the flap is detached from the arm and attached to the nose. – A flap of these dimensions transferred without a delay procedure would have a significant chance of distal necrosis. • Delay is occasionally used for pedicled TRAM breast reconstruction. ∘ The DIEA is ligated two weeks prior to flap transfer. • The mechanism of delay remains incompletely understood. • These theories have been proposed to explain the delay phenomenon: Increased axiality of blood flow • Removal of blood flow from the periphery of a random flap promotes development of an axial blood supply from its base. • Axial flaps have improved survival compared to random flaps. Tolerance to ischaemia • Cells become accustomed to hypoxia after the initial delay procedure. • Less tissue necrosis therefore occurs after the second operation. Sympathectomy vasodilatation theory • Dividing sympathetic fibres at the borders of a flap results in vasodilatation and improved blood supply. • But why, if sympathectomy is immediate, does the delay phenomenon only begin to appear at 48 hours, and why does it take 2 weeks for maximum effect? Intraflap shunting hypothesis • Postulates that sympathectomy dilates AVAs, resulting in an increase in nonnutritive blood flow bypassing the capillary bed. • A greater length of flap will survive at the second stage as there are fewer sympathetic fibres to cut and therefore less of a reduction in nutritive blood flow. General Principles 9 Hyperadrenergic state • Surgery results in increased tissue concentrations of vasoconstrictors, such as epinephrine and norepinephrine. • After the initial delay procedure, the resultant reduction in blood supply is not sufficient to produce tissue necrosis. ∘ The level of vasoconstrictor substances returns to normal before the second procedure. • The second procedure produces another rise in the concentration of vasoconstrictor substances. ∘ This rise is said to be smaller than it would be if the flap were elevated without a prior delay. • The flap is therefore less likely to undergo distal necrosis after a delay procedure. Unifying theory • Described by Pearl in 1981; incorporates elements of all these theories. Classification of flaps • Flaps can be classified by the five ‘C’s: ∘ Circulation ∘ Composition ∘ Contiguity ∘ Contour ∘ Conditioning. Circulation • Can be further subcategorised into: ∘ Random ∘ Axial (direct, fasciocutaneous, musculocutaneous, or venous). Random flaps • No directional blood supply; not based on a named vessel. • These include most local flaps on the face. • Should have a maximum length : breadth ratio of 1:1 in the lower extremity, as it has a relatively poor blood supply. ∘ Can be up to 6:1 in the face, as it has a good blood supply. Axial flaps Direct • Contain a named artery running in subcutaneous tissue along the axis of the flap. • Examples include: ∘ Groin flap, based on superficial circumflex iliac vessels. ∘ Deltopectoral flap, based on perforating vessels of internal mammary artery. • Both flaps can include a random segment in their distal portions after the artery peters out. 10 Chapter 1 Fasciocutaneous • Based on vessels running either within or near the fascia. • The fasciocutaneous system predominates on the limbs. • Fasciocutaneous flaps are classified by Cormack and Lamberty: Type A • Dependent on multiple non-named fasciocutaneous vessels that enter the base of the flap. • Lower leg ‘super flaps’ described by Pontén are examples of type A flaps. ∘ Their dimensions vastly exceed the 1:1 ratios recommended. Type B • Based on a single fasciocutaneous vessel, which runs along the axis of the flap. • Examples include scapular/parascapular flap, and perforator-based fasciocutaneous flaps of the lower leg. Type C • Supplied by multiple small perforating vessels, which reach the flap from a deep artery running along a fascial septum between muscles. • Examples include radial forearm flap (RFF) and lateral arm flap. Type C flaps with bone • Osteofasciocutaneous flaps, originally classified as type D. • Examples include: ∘ RFF raised with a segment of radius; lateral arm flap raised with a segment of humerus. • The Mathes and Nahai fasciocutaneous flap classification is slightly different: Type A • Direct cutaneous pedicle. • Examples: groin, superficial inferior epigastric and dorsal metacarpal artery flaps. Type B • Septocutaneous pedicle. • Examples: scapular and parascapular, lateral arm, posterior interosseous flap. Type C • Musculocutaneous pedicle. • Examples: median forehead, nasolabial and (usually) anterolateral thigh flap. Musculocutaneous • Flaps based on perforators that reach the skin through the muscle. • The musculocutaneous system predominates on the torso. • Muscle and musculocutaneous flaps were classified by Mathes and Nahai in 1981: General Principles 11 Type I • Single vascular pedicle. • Examples: gastrocnemius, tensor fasciae latae (TFL), abductor digiti minimi. • Good flaps for transfer – the whole muscle is supplied by a single pedicle. Type II • Dominant pedicle(s) and other minor pedicle(s). • Examples: trapezius, soleus, gracilis. • Good flaps for transfer – can be based on the dominant pedicle after the minor pedicle(s) are ligated. • Circulation via minor pedicles alone is not reliable. Type III • Two dominant pedicles, each arising from a separate regional artery or opposite sides of the muscle. • Examples: rectus abdominis, pectoralis minor, gluteus maximus. • Useful muscles for transfer – can be based on either pedicle. Type IV • Multiple segmental pedicles. • Examples: sartorius, tibialis anterior, long flexors and extensors of the toes. • Seldom used for transfer – each pedicle supplies only a small portion of muscle. Type V • One dominant pedicle and secondary segmental pedicles. • Examples: latissimus dorsi, pectoralis major. • Useful flaps – can be based on either the dominant pedicle or secondary segmental pedicles. Venous • Based on venous, rather than arterial, pedicles. • In fact, many venous pedicles have small arteries running alongside them. • The mechanism of perfusion is not completely understood. • Example: saphenous flap, based on long saphenous vein. ∘ Used to reconstruct defects around the knee. • Venous flaps are classified by Thatte and Thatte: Type 1 • Single venous pedicle. Type 2 • Venous flow-through flaps, supplied by a vein that enters one side of the flap and exits from the other. 12 Chapter 1 Type 3 • Arterialised through a proximal arteriovenous anastomosis and drained by distal veins. • Venous flaps tend to become congested post-operatively. • Survival is inconsistent; they have therefore not been universally accepted. • Modifying the type 3 arterialised venous flap by restricting direct arteriovenous shunting can improve survival rates by redistributing blood to the periphery of the flap. Composition • Flaps can be classified by their composition as: ∘ Cutaneous ∘ Fasciocutaneous ∘ Fascial ∘ Musculocutaneous ∘ Muscle only ∘ Osseocutaneous ∘ Osseous. Contiguity • Flaps can be classified as: ∘ Local flaps – Composed of tissue adjacent to the defect. ∘ Regional flaps – Composed of tissue from the same region of the body as the defect, e.g. head and neck, upper limb. ∘ Distant flaps – Pedicled distant flaps come from a distant part of the body to which they remain attached. – Free flaps are completely detached from the body and anastomosed to recipient vessels close to the defect. Contour • Flaps can be classified by the way they are transferred into the defect: Advancement • Stretching the flap • Excision of Burow triangles at the flap’s base • V-Y advancement • Z-plasty at its base • Careful scoring of the undersurface • Combinations of the above. Transposition • The flap is moved into an adjacent defect, leaving a secondary defect that must be closed by another method. General Principles 13 Rotation • The flap is rotated into the defect. • Classically, rotation flaps are designed to allow closure of the donor defect. • In reality, many flaps have elements of transposition and rotation, and may be best described as pivot flaps. Interpolation • The flap is moved into a defect either under or above an intervening bridge of tissue. Crane principle • This aims to transform an ungraftable bed into one that will accept a skin graft. • At the first stage, a flap is placed into the defect. • After sufficient time to allow vascular ingrowth into the flap from the recipient site, a superficial part of the flap is replaced in its original position. • This leaves a segment of subcutaneous tissue in the defect, which can now accept a skin graft. Conditioning • This involves delaying the flap, discussed in ‘Blood supply to the skin’. Geometry of local flaps Orientation of elective incisions • In the 19th century, Langer showed that circular awl wounds produced elliptical defects in cadaver skin. • He believed this occurred because skin tension along the longitudinal axis of the ellipse exceeded that along the transverse axis. • Borges has provided over 36 descriptive terms for skin lines, including: ∘ Relaxed skin tension lines (RSTLs) – these are parallel to natural skin wrinkles (rhytids) and tend to be perpendicular to the fibres of underlying muscles. ∘ Lines of maximum extensibility (LME) – these lie perpendicular to RSTLs and parallel to the fibres of underlying muscles. • The best orientation of an incision can be judged by a number of methods: ∘ Knowledge of the direction of pull of underlying muscles. ∘ Making the incision parallel to any rhytids or RSTLs. ∘ Making the incision perpendicular to LMEs. ∘ Making the incision parallel to the direction of hair growth. ∘ ‘The pinch test’ – if skin either side of the planned incision is pinched, it forms a transverse fold without distortion if it is orientated correctly; if a sigmoid-shaped fold forms, it is orientated incorrectly. Plasty techniques Z-plasty • Involves transposition of two adjacent triangular-shaped flaps. 14 Chapter 1 • Can be used to: ∘ Increase the length of an area of tissue or scar ∘ Break up a straight-line scar ∘ Realign a scar. • The degree of elongation of the longitudinal axis of the Z-plasty is directly related to the angles of its constituent flaps. ∘ 30∘ → 25% elongation ∘ 45∘ → 50% elongation ∘ 60∘ → 75% elongation ∘ 75∘ → 100% elongation ∘ 90∘ → 125% elongation. • The amount of elongation can be worked out by starting at 30∘ and 25% and adding 15∘ and 25% to each of the figures. • Gains in length are estimates; true values depend on local tissue elasticity and tension. • Flaps with 60∘ angles are most commonly used as they lengthen without undue tension. • The angles of the two flaps need not be equal and can be designed to suit local tissue requirements. ∘ However, all three limbs should be of the same length. • When designing a Z-plasty to realign a scar: 1 Mark the desired direction of the new scar. 2 Draw the central limb of the Z-plasty along the original scar. 3 Draw the lateral limbs of the Z-plasty from the ends of the central limb, to the line drawn in (1). 4 Two patterns will be available, one with a wide angle at the apex of the flaps, the other with a narrow angle. 5 Select the pattern with the narrower angle as these flaps transpose better. General Principles 15 The four-flap plasty • It is, in effect, two interdependent Z-plasties. • Can be designed with different angles. • The two outer flaps become the inner flaps after transposition. • The two inner flaps become the outer flaps after transposition. • The flaps, originally in an ‘ABCD’ configuration, end as ‘CADB’ (CADBury). C A A B A C or A B C D D C D D B B The five-flap plasty • Because of its appearance, this is also called a jumping-man flap. • Used to release first web space contractures and epicanthal folds. • It is, in effect, two opposing Z-plasties with a V-Y advancement in the center. • The flaps, originally in an ‘ABCDE’ configuration, end as ‘BACED’. A E B C D B C A D E The W-plasty • Used to break up the line of a scar and improve its aesthetics. • Unlike the Z-plasty, it does not lengthen tissue. • If possible, one of the limbs of the W-plasty should lie parallel to the RSTLs so that half of the resultant scar will lie parallel to them. • Using a template helps ensure each wound edge interdigitates easily. • The technique discards normal tissue, which may be a disadvantage in certain areas. 16 Chapter 1 RSTL Local flaps • Advancement flaps (simple, modified, V-Y, keystone, bipedicled). • Pivot flaps (transposition, interpolation, rotation, bilobed). Advancement flaps Simple • Rely on skin elasticity. General Principles Modified • Incorporate one of the following at the flap’s base to increase advancement: ∘ Counter incision ∘ Excision of Burow’s triangle ∘ Z-plasty. Counter incision at base Burow's triangle at base Z-plasty at base V-Y • These are incised along their cutaneous borders. • Their blood supply comes from deep tissue through a subcutaneous pedicle. • Horn flaps and oblique V-Y flaps are modifications of the original V-Y. 17 18 Chapter 1 Traditional V-Y flap Horn flap Keystone • Trapezoidal flaps used to close elliptical defects. • Essentially two V-Y flaps end-to-side. • Designed to straddle longitudinal structures, e.g. superficial nerves and veins, which are incorporated into the flap. • Blunt dissection to deep fascia preserves perforators and subcutaneous veins. • The lateral deep fascial margin can be incised for increased mobilisation. • The extremes of the donor site are closed as V-Y advancements, which produces transverse laxity in the flap. General Principles V-Y closure 90° x x V-Y closure 90° Bipedicled • Receive blood supply from both ends. • Less prone to necrosis than flaps of similar dimensions attached only at one end. • Example: von Langenbeck mucoperiosteal flap, used to repair cleft palates. • Bipedicled flaps are designed to curve parallel with the defect. ∘ This permits flap transposition with less tension. Original defect 2x x y 2y 2x Secondary defect 19 20 Chapter 1 Pivot flaps Transposition flaps • Transposed into the defect, leaving a donor site that is closed by some other means (often a skin graft). Line of greatest tension Area of excess skin or dog ear Pivot point Secondary defect Transposition flaps with direct closure of donor site • Include the rhomboid flap (Limberg flap) and Dufourmentel flap. • These are similar in concept but vary in geometry. • Both are designed to leave the donor site scar parallel to RSTLs. The rhomboid flap The rhomboid flap Excised area x x 120° 60° Lo x o ski se n RS TL LM E x x 60° x General Principles The Dufourmentel flap The Dufourmentel flap Long diagonal y b a c x° y Extended side of defect b x° y a Short diagonal c Parallel to long diagonal Interpolation flaps • Flaps raised from local, but not adjacent, skin. • The pedicle is passed either over or under an intervening skin bridge. Defect Intact skin bridge Skin paddle De-epithelialised skin pedicle Pivot point Rotation flaps • These large flaps rotate tissue into the defect. • Tissue redistribution usually permits direct closure of the donor site. • Flap circumference should be 5–8 times the width of the defect. • These are used on the scalp for hair-bearing reconstruction. • The back cut at the flap’s base can be directed towards or away from the defect. 21 22 Chapter 1 Back cut Burow's triangle x x 2x Pivot point The bilobed flap • Various designs have been described. • Consists of two transposition flaps. • The first flap is transposed into the original defect. • The second flap is transposed into the secondary defect – the donor site of the first flap. • The tertiary defect at the donor site of the second flap closes directly. ∘ This suture line is designed to lie parallel to RSTLs. • Esser, who first described the flap, put the first flap at 90∘ to the defect and the second flap at 90∘ to the first flap. • Zitelli modified these angles to 45∘ each, resulting in smaller dog ears. (a) Defect r r Pivot point (b) (c) RSTL Wound healing and skin grafts • Healing by primary intention ∘ Skin edges are directly opposed. ∘ Healing is normally good, with minimal scar formation. General Principles 23 • Healing by secondary intention ∘ The wound is left open to heal by a combination of granulation tissue formation, contraction and epithelialisation. ∘ More inflammation and proliferation occurs compared to primary healing. • Healing by tertiary intention ∘ Wounds are initially left open, then closed as a secondary procedure. Phases of wound healing 1 2 3 4 Haemostasis Inflammation Proliferation Remodelling. Haemostasis • Vasoconstriction occurs immediately after vessel division due to release of thromboxanes and prostaglandins from damaged cells. • Platelets bind to exposed collagen, forming a platelet plug. • Platelet degranulation activates more platelets and increases their affinity to bind fibrinogen. ∘ Involves modification of membrane glycoprotein IIb/IIIa (blocked by clopidogrel). • Platelet activating factor (PAF), von Willebrand factor (vWF) and thromboxane A2 stimulate conversion of fibrinogen to fibrin. ∘ This propagates formation of thrombus. • Thrombus is initially pale when it contains platelets alone (white thrombus). • As red blood cells are trapped, the thrombus becomes darker (red thrombus). Inflammation • Occurs in the first 2–3 days after injury. • Stimulated by physical injury, antigen–antibody reaction or infection. • Platelets release growth factors, e.g. platelet-derived growth factor (PDGF). ∘ Also release proinflammatory factors, e.g. serotonin, bradykinin, prostaglandins, thromboxanes and histamine. ∘ These increase cell proliferation and migration. • Endothelial cells swell, causing vasodilatation and allowing egress of polymorphonuclear neutrophils (PMNs) and monocytes into the tissue. • T lymphocytes migrate into the wound under the influence of interleukin-1. • Lymphocytes secrete various cytokines, including epidermal growth factor and basic fibroblast growth factor (bFGF). ∘ They also play a role in cellular immunity and antibody production. Proliferation • Begins on the 2nd or 3rd day and lasts for 2–4 weeks. • Monocytes mature into macrophages that release PDGF and transforming growth factor-β (TGF-β), which are chemoattractant to fibroblasts. • Fibroblasts, usually located in perivascular tissue, migrate along fibrin networks into the wound. 24 Chapter 1 • Fibroblasts secrete GAGs to produce ground substance, and then produce collagen and elastin. ∘ Initially, type III collagen is produced to increase the strength of the wound. • Some fibroblasts differentiate into myofibroblasts and effect wound contraction. • Angiogenesis occurs concurrently to supply oxygen and nutrients to the wound. ∘ Endothelial stem cells from blood vessels migrate through extracellular matrix. ∘ Attracted to the wound by angiogenic factors, thrombus and local hypoxia. • Zinc-dependent matrix metalloproteinases aid cell migration through tissues. Remodelling • Begins 2–4 weeks after injury and can last a year or longer. • During remodelling there is no net increase in collagen (collagen homeostasis). • Type III collagen is replaced by the stronger type I collagen. • Collagen fibres, initially laid down haphazardly, are arranged in a more organised manner. • The wound’s tensile strength approaches 50% of normal by 3 months; eventually becomes 80% as strong. • The extensive capillary network is no longer required and is removed by apoptosis, leaving a pale collagen scar. Abnormal scars • Classified as either hypertrophic or keloid. ∘ Keloids extend beyond the original wound margins. ∘ Hypertrophic scars are limited to original wound margins; commoner than keloids. • Increased numbers of mast cells in abnormal scars may account for the pruritus experienced by some patients. Hypertrophic scars • Usually occurs within 8 weeks of wounding. • Grow rapidly for up to 6 months before gradually regressing to a flat, asymptomatic scar. ∘ This may take a few years. • Typically form at locations under tension, e.g. shoulders, neck, presternal area, knees, ankles. • Microscopy shows well-organised type III collagen bundles with nodules containing myofibroblasts. Keloid scars • Dark-skinned individuals are more prone to keloid scars. • There is often a family history. • May develop at any point up to several years after minor injuries. • Typically persist for long periods of time and do not regress spontaneously. • Pain and hypersensitivity are associated more with keloids than hypertrophic scars. • Commonly form on anterior chest, shoulders, earlobes, upper arms and cheeks. • Excision typically results in recurrence. General Principles 25 • Microscopy shows poorly organised type I and III collagen bundles with few myofibroblasts. • Expression of proliferating cell nuclear antigen (PCNA) and p53 is upregulated. Epithelial repair • If the epidermal basement membrane is not breached, epithelial cells are replaced by upward migration of keratinocytes as in uninjured skin. • If the basement membrane is breached, re-epithelialisation must occur from the wound margins and, if present and intact, from epidermal appendages. • Re-establishing epithelial continuity consists of these four phases: Mobilisation • Epithelial cells at the wound edges elongate, flatten and form pseudopodia. • They detach from neighbouring cells and basement membrane. Migration • Decreased contact inhibition promotes cell migration. • Epithelial cells climb over one another to migrate. • As cells migrate, epithelial cells at the wound edge proliferate to replace them. • Cells migrate until they meet those from the opposite wound edge. • At this point, contact inhibition is reinstituted and migration ceases. Mitosis • Epithelial cells proliferate once they have covered the wound. • They secrete proteins to form a new basement membrane. • Cells reverse the morphological changes required for migration. • Desmosomes and hemidesmosomes are re-established to anchor themselves to the basement membrane and to each other. • This new epithelial cell layer forms a stratum germinativum and undergoes mitosis as in normal skin. Cellular differentiation • The normal structure of stratified squamous epithelium is re-established. Collagen • Constitutes approximately 30% of total body protein. • Formed by hydroxylation of amino acids lysine and proline by enzymes that require vitamin C as a cofactor. • Procollagen is initially formed within the cell. • Procollagen is transformed into tropocollagen after it is excreted from the cell. • Fully formed collagen has a complex structure. ∘ Consists of three polypeptide chains wound in a left-handed helix. ∘ These three chains are further wound in a right-handed coil to form the basic tropocollagen unit. 26 Chapter 1 • Collagen formation is inhibited by colchicine, penicillamine, steroids and deficiencies of vitamin C and iron. • Cortisol stimulates degradation of skin collagen. • Thus far, 28 types of collagen have been identified. • Each type shares the same basic structure but differs in the relative composition of hydroxylysine and hydroxyproline, and in the degree of cross-linking between chains. • The five most common types are: ∘ Type I: predominant in mature skin, bone and tendon. ∘ Type II: present in hyaline cartilage and cornea. ∘ Type III: present in healing tissue, particularly fetal wounds. ∘ Type IV: predominant constituent of basement membranes. ∘ Type V: similar to type IV. Also found in hair and placenta. • The ratio of type I collagen to type III collagen in normal skin is 5:1. ∘ Hypertrophic and immature scars contain ratios of 2:1 or less. • 90% of total body collagen is type I. The macrophage • Derived from mononuclear leukocytes. • Debrides tissue and removes micro-organisms. • Co-ordinates angiogenesis and fibroblast activity by releasing growth factors: ∘ PDGF, FGF 1 and 2, tumour necrosis factor alpha (TNF-α) and TGF-β. • Essential for normal wound healing. • Wounds depleted of macrophages heal slowly. The myofibroblast • First identified by Gabbiani in 1971. • Differs from a fibroblast – contains cytoplasmic filaments of α-smooth muscle actin, which are also found in smooth muscle. • Actin fibres within myofibroblasts are thought to be responsible for wound contraction. • The number of myofibroblasts within a wound is proportional to its contraction. • Increased numbers have been found in the fascia of Dupuytren’s disease. ∘ Thought to be responsible for the abnormal contraction of this tissue. TGF-𝛃 • Macrophages, fibroblasts, platelets, keratinocytes and endothelial cells secrete this growth factor. • Believed to play a central role in wound healing: ∘ Chemoattraction of fibroblasts and macrophages ∘ Induction of angiogenesis ∘ Stimulation of extracellular matrix deposition ∘ Keratinocyte proliferation. • Three isoforms have been identified: ∘ Types 1 and 2 promote wound healing and scarring; upregulated in keloids. ∘ Type 3 decreases wound healing and scarring – may have a role as an antiscarring agent. General Principles 27 • Fetal wounds have higher levels of TGF-β3 than adult wounds. ∘ TGF-β3 is thought to antagonise TGF-β1 and 2. ∘ May be one factor responsible for decreased inflammation and improved scarring observed in fetal tissue. Factors affecting healing • Systemic ∘ Congenital ∘ Acquired • Local. Systemic factors: congenital Pseudoxanthoma elasticum • Autosomal recessive. • Characterised by increased collagen degradation and mineralisation. • Skin is pebbled and extremely lax. • Most have premature arteriosclerosis in their 30s. Ehlers–Danlos syndrome • Heterogeneous collection of connective tissue disorders. • Most are autosomal dominant. • Results from defects in synthesis, structure or cross-linking of collagen. • Clinical features: ∘ Hypermobile fingers ∘ Hyperextensible skin ∘ Fragile connective tissues. • Surgery is avoided if possible – wound healing is poor. Cutis laxa • Presents in the neonatal period. • Skin is abnormally lax. • Patients have inelastic, coarsely textured, drooping skin. Progeria • Characterised by premature ageing. • Clinical features: ∘ Growth retardation ∘ Wrinkled skin ∘ Baldness ∘ Atherosclerosis. Werner syndrome • Autosomal recessive. • Skin changes similar to scleroderma. • Elective surgery avoided whenever possible – healing is poor. 28 Chapter 1 Epidermolysis bullosa • Heterogeneous collection of separate conditions. • Skin is very susceptible to mechanical stress. • Blistering may occur after minor trauma (Nikolsky sign). • The most severe subtype, dermolytic bullous dermatosis (DBD), results in hand fibrosis and syndactyly – the ‘mitten hand’ deformity. • Patients may develop squamous cell carcinoma in areas of chronic erosion. Systemic factors: acquired Nutrition • Vitamin A involved in collagen cross-linking; deficiency delays wound healing. • Vitamin C required for collagen synthesis. • Vitamin E acts as a membrane stabiliser; deficiency may inhibit healing. • Zinc, copper and selenium are important cofactors for many enzymes; administration accelerates healing in deficient states. • Hypoalbuminaemia is associated with poor healing. Pharmacological • Steroids decrease inflammation and subsequent wound healing. • Cytotoxics damage basal keratinocytes. • Non-steroidal anti-inflammatory drugs (NSAIDs) decrease collagen synthesis. • Anti-TNF-α drugs used in rheumatoid may increase post-operative wound complications. Endocrine abnormalities • Diabetics often have delayed wound healing; this is multifactorial. • Untreated hypothyroidism is associated with slow healing. Age • Cell multiplication rates decrease with age. ∘ All stages of healing are therefore protracted. • Healed wounds have decreased tensile strength in the elderly. Smoking • Nicotine is a sympathomimetic that causes vasoconstriction and consequently decreases tissue perfusion. • Carbon monoxide in cigarette smoke decreases oxygen-carrying capacity of haemoglobin. • Hydrogen cyanide in cigarette smoke poisons intracellular oxidative metabolism pathways. Local factors Infection • Subclinical wound infection can impair wound healing. • Wounds with >105 organisms per gram of tissue are considered infected and are unlikely to heal without further treatment. General Principles 29 Radiation • Causes endothelial cell, capillary and arteriole damage. • Irradiated fibroblasts secrete less collagen and extracellular matrix. • Lymphatics are also damaged, resulting in oedema and an increased infection risk. Blood supply • Decreased tissue perfusion results in decreased wound oxygenation. • Fibroblasts are oxygen-sensitive and their function is reduced in hypoxic tissue. • Reduced oxygen delivery results from decreases in: ∘ Inspired oxygen concentration ∘ Oxygen transfer to haemoglobin ∘ Haemoglobin concentration ∘ Tissue perfusion. • Decreased oxygen delivery to tissue reduces: ∘ Collagen formation ∘ Extracellular matrix deposition ∘ Angiogenesis ∘ Epithelialisation. • Hyperbaric oxygen increases inspired oxygen concentration but its effectiveness relies on good tissue perfusion. Trauma • The delicate neoepidermis of healing wounds is disrupted by trauma. Neural supply • There is evidence that wounds in denervated tissue heal slowly. • May contribute to delayed healing observed in some pressure sores, and in patients with diabetes and leprosy. • Mechanisms are poorly understood, but may be related to levels of chemoattractant neuropeptides in the wound. Fetal wound healing • Tissue healing in the first 6 months of fetal life occurs by regeneration rather than scarring. ∘ Regenerative healing is characterised by absence of scarring. • Normal dermal structures such as hair follicles form normally. • Regenerative healing differs from adult healing: ∘ Reduced inflammation. ∘ Reduced platelet aggregation and degranulation. ∘ Reduced angiogenesis. ∘ Epithelialisation is more rapid. ∘ Virtually no myofibroblasts and no wound contraction. ∘ Collagen deposition is rapid, organised and not excessive. ∘ More type III than type I collagen is laid down. ∘ The wound contains more water and hyaluronic acid. • Relative proportions of TGF-β isoforms may be responsible for some of these differences. 30 Chapter 1 Skin grafts • Skin grafts are either full or split thickness. • Split-skin grafts contain the epidermis and a variable amount of dermis. ∘ Usually harvested from thigh or buttock. • Full-thickness skin grafts contain the entire epidermis and dermis. ∘ Usually harvested from areas that allow direct closure of the donor defect. • Primary contraction is the immediate recoil observed in freshly harvested skin. ∘ Due to elastin in the dermis. • Secondary contracture occurs after the graft has healed. ∘ Due to myofibroblast activity. • The thicker the graft, the greater the degree of primary contraction. • The thinner the graft, the greater the degree of secondary contracture. Mechanisms • Skin grafts heal in four phases: Adherence • Fibrin bonds form immediately on applying skin graft to a suitable bed. Serum imbibition • Grafts swell in the first 2–4 days after application. • This results from absorption of fluid (serum imbibition). • The nutritive value of serum imbibition in maintaining graft viability is debated. Revascularisation • After 48–72 hours, capillary buds from the recipient bed have formed a fine vascular network in the fibrin layer between graft and wound. • Vessel ingrowth into skin grafts begins around the 4th day. • The mechanism of revascularisation is uncertain and may be via: ∘ Inosculation – direct anastomosis between vessels in the graft and those in recipient tissue. ∘ Revascularisation – new vessel ingrowth from recipient tissue along the graft’s vascular channels. ∘ Neovascularisation – new vessel ingrowth from recipient tissue along new channels in the graft. Remodelling • The histological architecture of the graft returns to that of normal skin. Reasons for graft failure Haematoma • Most common cause of graft failure. General Principles 31 • Risk of haematoma formation is minimised by: ∘ Meticulous haemostasis ∘ Use of meshed skin graft, which allows blood to escape ∘ Application of a firm dressing. Infection • Generally, skin grafts will not take if the bacterial count of the recipient site exceeds 105 organisms per gram. • Group A β-haemolytic Streptococcus can destroy grafts when present in much fewer numbers. ∘ This ability is attributed to secretion of proteases, such as streptokinase and hyaluronidase, which prevent adhesion. Seroma • Fluid collection under the graft reduces the likelihood of successful take. Shear • Lateral force applied to a graft. • Results in disruption of the delicate connections between graft and bed. Inappropriate bed • Skin grafts will not survive on bare cartilage, tendon and endochondral bone denuded of periosteum. • Membranous bone, found in some areas of the skull, will accept a skin graft. • Grafts on previously irradiated wound beds are prone to failure. Technical error • An assortment of technical errors can result in graft failure. • Examples: upside down graft placement, graft desiccation. Bone healing and bone grafts • Bones are derived from mesenchyme. • Composed of organic matrix (osteoid), which is mineralised by hydroxyapatite (a calcium salt). • Embryologically, bones form by one of two mechanisms. 1 Intramembranous ossification ∘ Occurs by deposition of bone within a vascularised membranous template. ∘ Examples: flat bones of the face, calvarium and ribs. 2 Endochondral ossification ∘ Develops from a cartilage precursor, or anlage. – In German, Anlage means primordium, plan or template. ∘ Examples: all long bones and the iliac crest. 32 Chapter 1 Bone structure • All bones have an outer cortical layer and an inner cancellous layer. ∘ The cancellous part of membranous bone is in the diploic space. • Cancellous bone consists of loosely woven trabeculae of organic and inorganic bone. • Cortical bone consists of: ∘ Multiple columnar bone units (osteons), composed of a central longitudinal canal (Haversian canal) that contains a central blood vessel. ∘ Transverse nutrient canals (Volkmann canals) connecting adjacent osteons. • Bone is laid down in concentric layers around each Haversian canal. • Osteocytes are scattered throughout osteons, each within its own space (lacuna). Blood supply to bone 1 2 3 4 Periosteal vessels at the sites of muscle attachment. Apophyseal vessels at the sites of tendon and ligament attachment. Nutrient arteries supplying the medullary cavity (endosteal supply). Epiphyseal vessels supplying growth plates. Bone healing • The phases of bone healing are similar to those of wound healing. 1 Haematoma formation 2 Inflammation – Fracture haematoma is gradually replaced by granulation tissue. – Osteoclasts remove necrotic bone. 3 Cellular proliferation – Stem cell recruitment. – Periosteal proliferation occurs on the outer aspect of the cortex. – Endosteal proliferation occurs on the inner aspect of the cortex. 4 Callus formation – Callus consists of immature woven bone produced by osteoblasts and hyaline cartilage produced by chondroblasts. – This soft callus (osteoid) is mineralised with hydroxyapatite to form hard callus (mature woven bone). 5 Remodelling – Woven bone is slowly replaced by lamellar bone. – This lasts until cortical structure and medullary cavity are restored. • Osteoblasts form new bone by producing osteoid. ∘ Derived from osteoprogenitor cells, under the influence of bone morphogenetic proteins (BMPs). ∘ They produce alkaline phosphatase, which has a role in bone mineralisation. • Osteoclasts are responsible for bone resorption. ∘ Derived from monocyte stem cells, similar to macrophages. ∘ They are large, multinucleate cells capable of phagocytosis. • Osteocytes are osteoblasts that have become trapped within lacunae in bone matrix. ∘ They maintain bone matrix and contribute to calcium homeostasis. General Principles 33 • Osteoid is the unmineralised, organic component of bone. ∘ Consists of proteins and ground substance made by osteoblasts. ∘ Type I collagen is the main protein; ground substance comprises chondroitin sulphate and osteocalcin. Primary bone healing • This is healing without callus formation. • Occurs if bone ends are directly apposed and fixed with absolute stability. • Fracture haematoma is removed during surgery. • The bone is ‘tricked’ into thinking it was never fractured. • Inflammatory and proliferative phases of healing do not occur. • Rather, it is a process of osteonal bone remodelling: ∘ Osteoclasts ‘drill’ across the fracture site from one cortex to the other. ∘ The tunnel allows blood vessels and osteoblasts to cross the fracture. ∘ This establishes new Haversian systems and normal bone architecture. Secondary bone healing • This is healing by callus formation. • Occurs if fragments are not rigidly fixed, or if a gap exists between bone ends. • It cannot occur if there is no fracture haematoma. Complications of fractures • Delayed union • Non-union • Malunion – rotation, angulation, shortening • Infection • Avascular necrosis (AVN) • Damage to adjacent structures. Bone graft healing • Bone graft materials may be: ∘ Biological – Autograft, allograft, xenograft ∘ Engineered biological – Growth factors, recombinant BMPs, stem cells, platelet-rich plasma concentrate (PRPC) ∘ Synthetic – Metals, ceramics, polymers. • Gold standard is autologous bone graft, usually harvested from iliac crest. • Autologous bone grafts heal by these mechanisms: Incorporation • This is adherence of the graft to the host tissue. • Incorporation is maximised in immobilised, well-vascularised tissue. 34 Chapter 1 Osseoconduction • Bone graft acts as a scaffold along which vessels and osteoprogenitor cells travel. • Old bone is resorbed as new is deposited. • Also known as creeping substitution. Osseoinduction • This is differentiation of mesenchymal cells within local tissue into osteocytes. • Osteoclasts, osteoblasts and osteocytes within bone graft are not capable of mitosis. • Increased numbers of these cells within bone graft are derived from the recipient site. • Osseoinduction is controlled by BMPs. Osteogenesis • This is formation of new bone by surviving cells within the bone graft. • It is how most new bone is formed in vascularised bone grafts (bone flaps). • Vascularised bone grafts incorporate more rapidly this way, without creeping substitution. • Not much osteogenesis occurs in non-vascularised bone grafts. Survival of bone grafts • Factors influencing survival of bone grafts include: 1 Systemic factors 2 Intrinsic graft factors 3 Factors relating to the placement of the graft. Systemic factors • Age • Nutrition • Immunosuppression • Drugs • Diabetes • Smoking • Obesity. Intrinsic graft factors • Grafts with periosteum included undergo less resorption than those without. • Membranous bone undergoes less resorption than endochondral bone when used as onlay grafts in the face. • Cancellous grafts are more easily revascularised than cortical grafts. Graft placement factors Orthotopic or heterotopic placement • Orthotopic – graft is placed into a position normally occupied by bone. • Heterotopic – graft is placed into a position not normally occupied by bone. • Grafts in an orthotopic position are less prone to resorption. General Principles 35 Quality of the recipient bed • Radiotherapy, scarring and infection adversely affect graft survival. Graft fixation • Rigidly fixed grafts survive better than mobile ones. Site of graft placement • Grafts survive better in areas in which bone is normally laid down (depository sites). ∘ Includes areas such as zygoma and mandible in children. Cartilage healing and cartilage grafts Cartilage structure • Derived from condensed mesenchyme. • Differentiates into chondroblasts that secrete extracellular matrix. • Chondroblasts eventually get trapped in lacunae within the matrix and become chondrocytes. • The matrix contains type II collagen, elastin and ground substance (GAGs). • Cartilage is classified according to the relative proportions of these three matrix components into: 1 Hyaline cartilage 2 Fibrocartilage 3 Elastic cartilage. • Its molecular structure confers tensile strength and elasticity. • This facilitates absorption and distribution of mechanical loads. • Large amounts of water within the matrix help maintain its three-dimensional structure. • Its viscoelastic properties allow it to resume its original shape after deformation. Cartilage nutrition • Cartilage has no intrinsic blood, nerve, or lymph supply. • Its water content is important because it relies on diffusion of nutrients and oxygen through the matrix. Cartilage healing • Chondrocytes show little reparative ability; healing is typically fibrous. • Lack of blood supply makes healing very slow. Cartilage grafts 1 Autografts 2 Allografts 3 Xenografts. 36 Chapter 1 Autografts • These are the gold standard. • Used for nose, ear and craniofacial reconstruction. • Donor sites include: ∘ Ear conchal bowl ∘ Nasal septum ∘ Costal cartilage. • Most cartilage grows from the deep layer of perichondrial connective tissue. ∘ Inclusion of perichondrium is therefore thought to be important for continued growth of cartilage after grafting. • Cartilage has a low metabolic rate; it is resistant to the ischaemia associated with grafting. • Compared with bone graft, it is more easily shaped and undergoes less resorption. • One major drawback is warping. ∘ This is a tendency to deform under mechanical stress over several days. • Gillies in 1920 noted that cartilage carved on one side would curve towards the opposite side. • This was originally thought to be due to tension in the perichondrium, but its removal did nothing to prevent warping. • Experiments subsequently showed the outer layer of cartilage acted as a ‘taut skin’, preventing it from expanding on the intact side. ∘ This phenomenon, known as Gibson’s principle, has practical use in prominent ear correction by the anterior scoring method. • Warping is most noticeable in the nasal dorsum due to thin overlying skin. • The naturally straight segment of the 10th or 11th rib shows minimal tendency to warp. • Most warping of cartilage grafts occurs within 60 minutes of transplantation, and continues for at least 4 weeks. • For this reason, delaying implantation for at least 30 minutes after harvest is advocated. ∘ This allows the cartilage to assume its eventual curvature prior to fixation. Allografts • Cartilage allografts are generally unsuccessful in plastic surgery. • The matrix is non-immunogenic and protects chondrocytes from circulating lymphocytes. • However, once the matrix breaks down, chondrocytes are exposed and undergo rejection. • This explains the slow but steady resorption of cartilage allografts. Xenografts • These remain immunogenic even after processing. • They are therefore unsuitable for human implantation. Nerve healing and nerve grafts Nerve anatomy and function • Nerve cells (neurons) consist of a cell body from which nerve fibres project. • Outgoing impulses are carried by nerve fibres called axons. General Principles • • • • • • • • • • • 37 Impulses are received either on the cell body or nerve fibres called dendrites. Endoneurium surrounds individual nerve fibres or axons. Perineurium surrounds groups of nerve fibres (fascicles). Intraneural epineurium contains blood vessels and surrounds perineurium. The outer epineurium surrounds groups of fascicles to form a peripheral nerve. Schwann cells produce the multilaminated myelin sheath of myelinated nerves. Unmyelinated nerves are ensheathed by a Schwann cell-derived double basement membrane. Schwann cells of myelinated nerves abut at nodes of Ranvier. Nerve conduction involves passage of an action potential along a nerve. The impulse in myelinated nerves jumps between adjacent nodes of Ranvier. ∘ Known as saltatory conduction. Nerve fibres are classified based on their diameter: Group A • Myelinated, large-diameter, high-conduction velocity nerves. ∘ Group A-α fibres: motor and proprioception. ∘ Group A-β fibres: pressure and proprioception. ∘ Group A-γ fibres: motor to muscle spindles. ∘ Group A-δ fibres: pain, touch, temperature. Group B • Myelinated, small-diameter, low-velocity fibres. • Found in preganglionic autonomic nerves. Group C • Unmyelinated, small-diameter, low-velocity fibres, found in: ∘ Postganglionic autonomic nerves • Dorsal root nerves for pain, temperature, touch, pressure and itch. Medical Research Council grading of nerve function • The MRC have recommended the following grading of nerve function: Motor function M0 M1 M2 M3 M4 M5 No contraction Flicker Movement with gravity eliminated Movement against gravity Movement against resistance Normal Sensory function S0 S1 S1+ S2 S2+ S3 S3+ S4 No sensation Pain (deep) Pain (superficial) Pain and some touch S2 with over-response S2 without over-response Imperfect two-point discrimination Normal 38 Chapter 1 Injury • After nerve transection, degeneration occurs proximally to the nearest node of Ranvier. • Distally, nerves undergo Wallerian degeneration. • This process was described by Waller in 1850 and consists of: ∘ Degeneration of axons and myelin. – Phagocytosed by macrophages and Schwann cells. ∘ Remaining basement membranes form endoneurial tubes that have a bandlike appearance on electron microscopy. – Known as bands of Büngner. – Important for guiding regenerating axons to their targets. • Neurotropism is selective, directional growth of fibres towards end organs. ∘ Mediated by nerve growth factors and cell–cell interactions: 1 The proximal axon sprouts many new daughter axons, forming a growth cone. 2 Fibres growing in an inappropriate direction atrophy. 3 Those growing in the correct direction survive. • Neurotrophism is non-selective, non-directional growth of nerve fibres. • Neurotrophic factors are almost all produced by Schwann cells: ∘ Growth factors – Nerve growth factor, ciliary neurotrophic factor, insulin-like growth factor. ∘ Extracellular matrix components – Fibronectin, laminin, neural cell adhesion molecule, N-cadherin. Classification of nerve injury • Degree of nerve injury has been classified by Seddon and Sunderland. • Seddon classification: 1 Neurapraxia 2 Axonotmesis 3 Neurotmesis. • Sunderland expanded this classification: First-degree injury • Axon remains in continuity although conduction is impaired. • Recovery should be complete. Second-degree injury • Axonal injury occurs and the segment of nerve distal to the site of damage undergoes Wallerian degeneration. • All connective tissue layers remain intact and recovery should be good. Third-degree injury • Axon and endoneurium are divided. • Perineurium and epineurium remain intact. • Recovery should be reasonable. General Principles 39 Fourth-degree injury • Complete division of all intraneural structures. • Epineurium remains intact. • Recovery of some function is expected. • May result in a neuroma-in-continuity. Fifth-degree injury • Nerve trunk completely divided. • Early surgical repair is mandatory for any recovery. • Mackinnon added a sixth-degree injury to the classification. ∘ This is a mixed pattern nerve injury with segmental damage. • Seddon’s neurapraxia equates to a Sunderland first-degree injury. • Axonotmesis equates to a second-, third- or fourth-degree injury. • Neurotmesis equates to a fifth-degree injury. Nerve repair • Nerve repair by direct approximation should be performed where possible. • Nerve ends are trimmed and an epineurial repair under magnification with fine sutures is done. • Fascicles of nerve trunks should be aligned if possible. • Repairs should not be under undue tension. • Some authorities state primary repair should only be performed when a single 9/0 suture is strong enough to appose the nerve ends. • Clinical studies have not shown clear superiority of fascicular repair over epineurial repair. Fascicular identification • The following can aid fascicular matching during nerve repair. Matching of anatomical structures • Size and orientation of fascicles • Distribution of vessels on the nerve’s surface. Electrical stimulation • Motor nerves respond to stimulation for up to 72 hours after division. • Stimulation of the distal stump can differentiate motor from sensory fibres. • Stimulation in a conscious patient can differentiate motor from sensory fibres in the proximal stump: ∘ Stimulation of sensory fibres produces sharp pain. ∘ Stimulation of motor fibres feels like a dull ache. Knowledge of internal nerve topography • The fascicular layout of many nerves is known and can be used to aid accurate repair. • Ulnar nerve motor fascicles lie centrally between volar sensory branches from the palm and dorsal sensory branches from the dorsal hand. 40 Chapter 1 Nerve grafts • Required if primary repair not possible without undue tension. • For large nerves, multiple cables of smaller donor nerves may be required to bridge the defect. • Tension across the repair can be reduced by mobilising the nerve proximally and distally, and: ∘ Anterior transposition of the ulnar nerve at the elbow. ∘ Intratemporal dissection of the facial nerve. • Nerve gaps can be bridged by autografts, allografts, or synthetic materials. ∘ Autologous nerve is the gold standard. Composition • Autologous tissues used to bridge nerve gaps include: ∘ Fresh nerve ∘ Freeze–thawed muscle ∘ Segments of vein. • Allograft nerves require systemic immunosuppression to prevent rejection. • Immunosuppression is withdrawn after Tinel’s sign has progressed into the distal nerve. • Tacrolimus is the immunosuppressant of choice due to its neuroregenerative properties. • Absorbable synthetic nerve tubes of polyglycolic acid have been trialled. Autologous grafts • Common sources of autologous grafts: Sural nerve • Passes behind lateral malleolus. • Proximally, it divides into medial sural and peroneal communicating branches. • Lengths up to 30–40 cm are available in adults. • Can be harvested endoscopically. Lateral antebrachial cutaneous nerve • Lies adjacent to cephalic vein alongside ulnar border of brachioradialis. • Lengths up to 8 cm are available. • Harvest results in limited loss of sensation due to territory overlap with adjacent nerves. Medial antebrachial cutaneous nerve • Found in the groove between triceps and biceps, alongside basilic vein. • Distally, divides into anterior and posterior branches. • Posterior branch preserved if possible – supplies the resting part of elbow and forearm. • Lengths up to 20 cm are available. The terminal branch of the posterior interosseous nerve • Useful for bridging small defects in small-diameter nerves. • Located in the base of the fourth extensor compartment of the wrist. • Only a relatively short length of nerve graft is available. General Principles 41 Principles • Both nerve ends are trimmed back to healthy tissue. • Grafts are reversed to funnel regenerating axons distally. • Place grafts on a healthy vascular bed, or transfer as a vascularised graft. • Avoid tension on the graft. • Stagger the level of repair between separate cables. • Separate cables from each another as they bridge the defect. • Proper sensory and motor alignment should be restored. Tendon healing Anatomy • Tendons are composed of dense, metabolically active connective tissue. • Collagen bundles are arranged in a regular spiralling fashion. ∘ Collagen is predominantly type I, with small amounts of types III and IV. • Tendons contain few cells; those that are present include: ∘ Tenocytes ∘ Synovial cells ∘ Fibroblasts. • Endotendon encloses tendon bundles. ∘ Continuous with perimysium proximally and periosteum distally. • Epitenon is the outer layer of synovial tendons. • Paratenon is a loose adventitial layer that surrounds extra-synovial tendons. ∘ These layers contain blood vessels. • Flexor tendons receive blood supply from: 1 Musculotendinous junction 2 Bony insertion 3 Mesenteric vincular vessels. • An avascular zone exists on the volar (frictional) surface of the tendon. • Extensor tendon blood supply is similar, except that: 1 A long mesotenon exists within the synovial-lined extensor retinaculum. 2 There is no vincular supply. • Over the dorsal wrist, extensor tendons are arranged into six synovial-lined compartments: ∘ 1st compartment: abductor pollicis longus, extensor pollicis brevis. ∘ 2nd compartment: extensor carpi radialis longus and brevis. ∘ 3rd compartment: extensor pollicis longus. ∘ 4th compartment: extensor indicis and extensor digitorum. ∘ 5th compartment: extensor digiti minimi. ∘ 6th compartment: extensor carpi ulnaris. Mechanisms of tendon healing Extrinsic healing • Dependent on fibrous attachments forming between tendon sheath and tendon. 42 Chapter 1 • Historically believed to be the sole mechanism of tendon healing. • Led to development of post-operative protocols that immobilised tendons in the mistaken belief that this maximised tendon healing. Intrinsic healing • Dependent on: ∘ Blood flow through long and short vinculae. ∘ Diffusion of nutrients from synovial fluid. • Lunborg showed tendons heal when wrapped in a semipermeable membrane and placed in the knee joint of a rabbit. ∘ Enclosing the tendons in semipermeable membrane stimulates intrinsic healing as it permits passage of nutrients, but not cells. • Discovery of intrinsic healing led to early post-operative mobilisation (see Chapter 5, ‘Hand trauma’). Phases of tendon healing • Similar to those of wound healing. Inflammation • Inflammatory cells infiltrate the wound. • Secrete growth factors that attract fibroblasts. Proliferation • Fibroblasts are responsible for tissue proliferation. • They secrete type III collagen and GAGs. • Collagen is initially arranged randomly; consequently, the tendon lacks strength. Remodelling • Begins approximately 3 weeks following tendon injury. • Type III collagen is replaced by type I. • The tendon remodels into an organised structure. • Early motion limits fibrous attachments between tendon and sheath. ∘ It therefore promotes intrinsic healing at the expense of extrinsic healing. ∘ Mobilised tendons are stronger than immobilised tendons. Transplantation • Transplantation is transfer of tissue from one body location to another. ∘ Orthotopic transfers are transplants into an anatomically similar site. ∘ Heterotopic transfers are transplants into an anatomically different site. • Transplant tissue types are classified as follows: 1 Autografts ∘ Transplantation within the same individual. ∘ Includes all flaps and grafts. ∘ Flaps carry intrinsic blood supply with them; grafts do not. General Principles 43 2 Isografts ∘ Transplantation between genetically identical individuals. 3 Allografts ∘ Transplantation between different individuals of the same species. ∘ Also called homografts. ∘ Large burns can be temporarily covered with allograft skin. 4 Xenografts ∘ Transplantation from one species to another. ∘ Previously called heterografts. ∘ Porcine skin grafts can be used as temporary cover for burns. ∘ Implantable materials, e.g. Permacol and Strattice, are modified porcine xenografts. Transplant immunology History • Gibson and Medawar were pioneers of transplant immunology in the 1940s and 1950s. • They described the second set phenomenon, defined as ‘accelerated rejection of allogenic tissue due to the presence of humoral antibodies from prior exposure to the same allogenic source’. • The first set reaction occurs when skin allograft is applied to an individual for the first time. • The first set reaction is characterised by: 1 During the first 1–3 days, allograft behaves in a fashion similar to autograft in that it develops dilated capillaries with no blood flow. 2 Between 4 and 7 days, leukocytes and thrombi infiltrate the graft; punctate haemorrhages appear within its vessels. 3 Between 7 and 8 days, blood flow ceases and the skin graft necroses. • The second set reaction occurs in patients who have been previously grafted with the same allograft material. • The second set reaction is characterised by: 1 Immediate hyperacute rejection. 2 The graft never undergoes any revascularisation, termed a ‘white graft’. Immunology • Rejection occurs when the host immune system recognises foreign antigens. • ABO blood group antigens are potent barriers to transplantation. ∘ ABO matching is easily achieved but other antigens also mediate rejection. • These antigens are encoded in the major histocompatibility complex (MHC). ∘ In humans, these are known as human leukocyte antigens (HLAs). • HLAs of significance are six closely linked genes on the short arm of chromosome 6 and are divided into two classes: ∘ Class I: HLA-A, -B and -C; found on all nucleated cells and platelets. ∘ Class II: HLA-DP, -DQ and -DR; found on APCs. – APCs include monocytes, macrophages, dendritic cells (called Langerhans cells in skin), B lymphocytes and activated T cells. • HLA-A, -B and -DR are the most important mediators of tissue rejection. 44 Chapter 1 • HLAs on APCs can be recognised by T cells via two separate pathways: 1 Direct pathway – Unique to transplantation. – Recipient T cells recognise HLAs on donor APCs within transplanted tissue. – Initiates a strong immune response. – Thought to be the major route for initiating acute rejection. 2 Indirect pathway – Physiological pathway activated in response to non-self antigens, e.g. viruses. – Recipient T cells recognise donor HLAs after processing by recipient APCs. • Host immune response is co-ordinated by T helper (Th ) cells. ∘ Activation of Th cells by direct or indirect pathways induces them to differentiate along the Th 1 (cell-mediated response) or Th 2 (humoral response) route. – Release of IL-12 from APCs favours Th 1 differentiation; IL-4 favours Th 2 differentiation. • Th 1 cells release the cytokines IL-2, IFN-γ, TNF-α and TNF-β. ∘ These activate macrophages and natural killer (NK) cells that cause direct graft cell lysis. – Known as delayed type hypersensitivity (DTH) reaction. ∘ Cytotoxic CD8 T cells are also stimulated to destroy allograft cells by inducing apoptosis (Fas activation) and releasing lytic enzymes. • Th 2 cells release interleukins, particularly IL-4. ∘ Stimulate B cells to mature into antibody-producing plasma cells. ∘ These antibodies stimulate tissue destruction by complement fixation, or by targeting neutrophils, eosinophils, macrophages and NK cells to the graft. • A combination of Th 1 and Th 2 responses occurs in most immune reactions. • IL-2 is the principal T-cell growth factor. ∘ An important target for immunosuppressive drugs. Hyperacute rejection • Occurs within minutes. • Pre-existing antibodies to the donor, e.g. anti-ABO blood group antibodies, activate complement. • The allograft must be removed immediately to prevent systemic inflammatory response. • Seen with some xenografts: ∘ Discordant transplantation occurs when natural antibodies between species are present, e.g. pig to human. ∘ Concordant transplantation occurs when natural antibodies are not present, e.g. primate to human. Acute rejection • Occurs after 1 week due to the delay in T-cell activation. • May occur years after transplantation. • Usually treated with a short course of high-dose corticosteroids. • Recurrent episodes may lead to chronic rejection. General Principles 45 Chronic rejection • Poorly understood chronic inflammatory and immune response. • Irreversible; treatments, other than re-transplantation, are ineffective. Immunosuppression • Subdivided into non-specific and specific modalities. • Non-specific techniques of immunosuppresion: Radiation • Whole-body radiation removes mature lymphocytes; not used in humans. • Localised lymphoid tissue irradiation is specifically targeted, e.g. thymus. • Graft irradiation reduces antigenicity by destroying Langerhans cells in skin. Drugs • Three main groups of immunosuppressants: 1 Steroids, e.g. prednisolone – Anti-inflammatory and immunosuppressive. – Usually used in combination with other agents. 2 Cytotoxics, e.g. cyclophosphamide, methotrexate, mycophenolate mofetil, azathioprine. – Interfere with DNA replication; kill proliferating lymphocytes. 3 Fungal or bacterial products, e.g. ciclosporin, tacrolimus, sirolimus. – Ciclosporin and tacrolimus block calcineurin activation. • Decrease production of IL-2 and subsequent T-cell activation. – Sirolimus (or rapamycin) is a newer drug that blocks lymphocyte proliferation and differentiation. • It inhibits mammalian target of rapamycin (mTOR) protein. Biological agents • Anti-lymphocyte serum is made by injecting another species with lymphoid tissue from the recipient. • The resulting polyclonal anti-thymoglobulin (ATG) and anti-lymphocyte sera (ALS) deplete recipient T cells. • Specific techniques of immunosuppression involve monoclonal antibodies directed towards specific antigens. ∘ Basiliximab prevents IL-2-mediated clonal expansion of activated lymphocytes. ∘ This is an area of intense research as new antibody targets are discovered. Immunological tolerance • Transplant research is focused on development of immunological tolerance. • Tolerance is the state of immunologic acceptance or unresponsiveness of a recipient to donor allograft or xenograft. • Induction of tolerance allows transplantation without need for immunosuppression. 46 Chapter 1 Vascularised composite allotransplantation (VCA) • VCA involves transplantation of various tissues such as skin, nerve, blood vessel, muscle and bone from one human to another. • Previously known as composite tissue allotransplantation (CTA). • Examples pertinent to plastic surgery include limb and face transplantation. History • A hand transplant was performed in Ecuador in 1963, but was acutely rejected within a few weeks. • In 1997, the International Symposium on CTA was held in Louisville, Kentucky, to discuss possible human hand allotransplantation. ∘ Concluded that it was appropriate to consider undertaking the procedure. • The first successful hand transplant was performed in 1998 by an international surgical team assembled in Lyon, France. ∘ This was repeated in 1999 by units in Louisville, USA and Guangzhou, China. • Thus it became clear that modern immunosuppressive drugs could allow skin, muscle and bone allotransplants to survive and function. • This stimulated interest in face transplantation. • Facial transplantation was shown to be technically possible by a microsurgical team in India led by Abraham Thomas. ∘ In 1994 they reattached the face and scalp of a 9 year-old girl after it was avulsed by a machine. • In 2002, Peter Butler discussed the potential for face transplantation at the BAPS Winter Meeting. • A working party set up by the Royal College of Surgeons of England examined all aspects of the proposed procedure. ∘ They reported in 2003 that further research was required before facial transplantation could be performed. • The Comité Consultatif National d’Ethique (CCNE) in France produced a report in 2004. ∘ They concluded that a partial face transplant involving the mouth–nose triangle could be performed. • The first successful partial face transplant was done in 2005 by a team based in Amiens, France. • The first full face transplant was done in Barcelona by a Spanish team in 2010. • At the time of writing, the most extensive face transplant was performed in 2012 at the R Adams Cowley Shock Trauma Center in Baltimore, Maryland. ∘ The transplant replaced almost everything from the coronal plane of the scalp to the clavicles. • The first British VCA was a right hand transplant performed by the UK Hand Transplant Programme in Leeds on 27th December 2012. Technical considerations • Routine techniques of microsurgery and organ harvest, refined over many years. General Principles 47 Biological considerations • High rejection rates were anticipated due to the perceived high antigenicity of skin. • This is not borne out in practice: ∘ Immunosuppressant regimes for VCAs are virtually identical to those for solid organ transplantations. ∘ Most employ either basiliximab or ATG for induction therapy, and triple maintenance therapy with tacrolimus, mycophenolate mofetil and prednisolone. Ethical considerations • Although VCAs enhance quality of life, they are not essential for life. • Quality of life is a subjective judgement that varies between VCA recipients. Psychological considerations • These are at the forefront of VCA research. • Transplantation may have unpredictable psychological effects: ∘ Anxiety – Regarding the transplant, rejection, side effects of medication. ∘ Identity – Integration of the VCA into body image, self-recognition. ∘ Adjustment – Ability to adjust is not well predicted by the severity of disfigurement. Consent • Must be completed well in advance of a transplant. ∘ There is insufficient time once a suitable donor is identified. Patient selection • A comprehensive and coherent protocol is used to select suitable patients. • Should address physical, psychological and social attributes of the recipient. Tissue engineering • Langer and Vacanti, considered the fathers of tissue engineering, define this term as ‘an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ’. • The first tissue-engineered implant was a chondrocyte-seeded synthetic scaffold shaped into a sternum. ∘ Used to treat a case of Poland’s syndrome in 1991. • Engineered constructs made of patients’ own cells do not require immunosuppression. • Constructs may be created in vitro or in vivo. • They use cells cultured from mature cells or adult-derived stem cells. • Constructs can be pre-laminated with different cell types, e.g. skin, cartilage. 48 Chapter 1 • Intrinsic blood supply can be provided by embedding engineered capillaries. • A reliable extrinsic blood supply allows free vascularised transfer. ∘ This would minimise risks of tissue necrosis and resorption. • A method of achieving this in vivo is to use the capsule that forms around implanted foreign bodies. ∘ Transposing a vascular pedicle onto a silicone mould will form a fibrous capsule that incorporates the pedicle vessels. • The capsule provides: 1 A closed compartment for cultured cells. 2 Nutrients for cells via the capsule’s blood supply. 3 A bridge between intrinsic blood supply and incorporated vascular pedicle. • After 2–3 weeks the capsule can be elevated on its pedicle and transferred to the recipient site. • The silicone mould is removed and cultured cells are implanted into the capsule. • Engineered autogenous tissue can then form. • Neumeister famously achieved this in 2006 using an ear-shaped silicone block in a rat. • Pairing an engineered intrinsic vascular supply with an engineered extrinsic vascular pedicle could potentially allow ‘spare parts’ to be completely manufactured ex vivo. Alloplastic implantation • The ideal implant should be: 1 Non-allergenic, causing minimal soft tissue reaction. 2 Strong and fatigue resistant, but easy to shape and mould. 3 Resistant to absorption, corrosion or deformation. 4 Non-carcinogenic. 5 Non-supportive of growth of micro-organisms. 6 Sterilisable. 7 Radiolucent. 8 Inexpensive. 9 Readily available. Indications • Stabilisation of fractures. • Reconstruction or augmentation of soft tissue and bony defects. Relative contraindications • • • • Implantation within a radiotherapy field. Poor surrounding blood supply. Tenuous soft tissue coverage. Infection. Classification • Implants can be classified into: General Principles ∘ ∘ 49 Liquids (silicone, collagen preparations, hyaluronic acid preparations) Solids (metals, polymers, ceramics). Liquids Silicone • Silicon is an element. • Silica is silicone dioxide, commonly found as sand or quartz. • Silicone consists of a monomer backbone of silicon and oxygen with methyl, vinyl, or phenol side groups in a varying number of repeating units. • In medical terms, ‘silicone’ usually refers to polydimethylsiloxane. • Short polymer chains produce a viscous liquid. • Long polymer chains produce a firmer, cohesive gel. • Cross-linking of the chains produces solid silicone. • Silicone is biologically inert but elicits a mild foreign body reaction with subsequent capsule formation. • Synovitis can occur when silicone prostheses are used in joint arthroplasty. • Bioplastique™ consists of textured silicone-rubber microparticles mixed with water in a hydrogel carrier. • The ‘silicone controversy’ is discussed in Chapter 4, ‘Breast augmentation’. Collagen preparations Zyderm® 1 and 2 • Made from sterilised, fibrillar bovine dermal collagen. • Composed of 95% type I collagen and 5% type III collagen. • Forearm skin testing is required 4 weeks prior to treatment to exclude allergy. • Effects last up to 6 months, until the body degrades the collagen. • Collagen concentration in Zyderm 1 is 35 mg/ml, and 65 mg/ml in Zyderm 2. • Administered by intradermal injection; used for superficial wrinkles. • Absorption of the water carrier reduces the injected volume by 30%. ∘ Defects should therefore be overcorrected initially. Zyplast® • Formed by cross-linking collagen with glutaraldehyde. • Firmer than Zyderm 1 or Zyderm 2. • Used to treat deep dermal defects and coarse rhytids. • Little absorption occurs; overcorrection is not recommended. Autologen™ • Harvested from autologous collagen. • Autologous skin is obtained from skin biopsy or from excised skin after facelift or abdominoplasty. • Skin is processed into a collagen suspension at concentrations of 25–100 mg/ml. • It has two advantages over bovine collagen: 1 Allergic reactions should not occur. 2 Contains intact dermal collagen fibres that are more resistant to degradation. 50 Chapter 1 Hyaluronic acid preparations • A number of preparations composed of synthetic hyaluronic acid are available. ∘ Examples: Restylane®, Perlane®, Juvéderm®. • Average absorption rates are 20–50% of the original volume by 6 months. • Do not tend to cause allergic reactions. • Typically injected superficially, to treat wrinkles or increase lip definition. Solids Metals Stainless steel • Alloy of iron, chromium and nickel. • Relatively high incidence of corrosion and implant failure. • Galvanic currents between screws and plates can result in corrosion. Vitallium • Alloy of chromium, cobalt and molybdenum. • Does not corrode like stainless steel. • Higher tensile strength than stainless steel and titanium. Titanium • An element, not an alloy. • Tensile strength similar to vitallium. • May be alloyed with aluminium and vanadium for plates and screws. • More malleable and less prone to corrosion than stainless steel or vitallium. • Less likely to produce artefact on MRI or CT scanning. • Titanium implants are synonymous with osseointegration. Gold • Resistant to corrosion but low tensile strength. • Used primarily as an upper eyelid weight in facial palsy. Polymers Polyurethane • Induces intense foreign body reaction, followed by tissue adhesion. • Breast implants covered with polyurethane foam have a low rate of capsular contracture. • Initial concerns about carcinogenesis from a polyurethane breakdown product (2,4 toluene diamine, TDA) in humans led to the withdrawal of these breast implants in 1991. • However: ∘ 2,4 TDA has not been found in the blood of patients with polyurethane implants. ∘ 2,4 TDA found in urine was an artefact of the assay, which used strong hydrochloric acid boiled for an hour at 105 ∘ C. – This cleaved 2,4 TDA from harmless polyurethane breakdown oligomers. General Principles 51 • The UK Committee on Carcinogenicity concluded that the carcinogenic risk of these implants is small and unquantifiable. • They were reintroduced in the United Kingdom in 2005, but are not FDA approved in the United States at this time. Fluorocarbons • Bonding between fluorine and carbon results in an extremely stable biomaterial. • No human enzyme can break the bond between these two elements. • The most common fluorocarbon in surgery is polytetrafluoroethylene (PTFE). ∘ Marketed as Teflon® by DuPont™. Proplast® I • A black composite of PTFE and carbon. • Historically used for facial bony augmentation. Proplast® II • A white composite of PTFE and aluminium oxide. • Historically used for more superficial augmentation. • High complication rates (infection, extrusion, etc.) with Proplast temporomandibular joint implants resulted in its withdrawal from US markets. • The manufacturer went into liquidation; these products are no longer available. Gore-Tex® • A sheet of expanded PTFE. • Soft but strong and allows some tissue ingrowth. • Available as sheets and blocks. • Used for vascular prostheses since 1971. • Approved for facial augmentation in the United States since 1994. Polyethylene • Has a simple carbon chain structure and does not contain fluorine. • Available in three grades: 1 Low density 2 High density 3 Ultra-high molecular weight. • Medpor® is high-density, porous polyethylene. ∘ Commonly used for augmenting the facial skeleton. ∘ Elicits little foreign body reaction. ∘ Some soft tissue ingrowth does occur, which stabilises the implant. ∘ Implants are available in a variety of preformed shapes. • Ultra-high molecular weight polyethylene used in load-bearing orthopaedic implants. 52 Chapter 1 Polyester • Dacron® is made from high-density fibres of polyethylene terephthalate (PET). ∘ Preferred polymer for arterial prostheses. • Biodegradable polyesters include polyglycolic acid and poly-L-lactic acid. ∘ Degraded by hydrolysis over several months. ∘ Available as miniplates, screws and distraction devices for craniofacial surgery. • An absorbable injectable filler of poly-L-lactic acid microparticles is marketed as Sculptra®. Polypropylene • Structure similar to polyethylene. • Has a methyl group instead of hydrogen atom in each monomer unit. • Marlex® polypropylene mesh has high tensile strength and allows tissue ingrowth. Polymethylmethacrylate (PMMA) • Self-curing acrylic resin, used for: ∘ Securing artificial joint components ∘ Craniofacial bone augmentation ∘ Fabrication of gentamicin-impregnated beads. • Available in two forms: 1 A paste that cures, forming a solid block 2 Preformed implants. • Methylmethacrylate elicits an exothermic reaction during curing. • When used for calvarial remodelling, it should be cooled to avoid soft-tissue burns – temperatures up to 70 ∘ C have been recorded. • Artecoll® and Artefill® are permanent injectable fillers composed of PMMA microspheres suspended in 3.5% bovine collagen. ∘ Injected subdermally and massaged to prevent clumping. ∘ The collagen is absorbed but the PMMA is encapsulated. ∘ 64% of patients reported lasting effects at 2-year follow-up. Cyanoacrylate • Main constituent of adhesives such as Super Glue®. • Strong, biodegradable tissue adhesive. • The adhesives polymerise on contact with water in an exothermic reaction. • Clinically used for: ∘ Opposing skin edges ∘ Securing skin grafts ∘ Securing nails to nailbeds. • Useful for simple lacerations in children, as it avoids the pain of suturing. • Examples: Histacryl®, Dermabond®, LiquiBand®. Calcium ceramics • Three main types: 1 Calcium sulphate 2 Calcium carbonate 3 Calcium phosphate. General Principles 53 Calcium sulphate • Commercially available as Osteoset®. ∘ Dissolves in body fluids faster than bony ingrowth. • More commonly used as plaster of Paris. Calcium carbonate • Found in some corals. • Not used as calcium carbonate – hydrothermally converted to hydroxyapatite. • Commercially available as Biocoral®. Calcium phosphate • The major inorganic constituent of bone. • Available in two forms: 1 Tricalcium phosphate – This is remodelled and resorbed in an osteogenic environment. – Examples: ChronOS™, Vitoss®, Biosorb®. 2 Apatite – Remodels slowly. – Hydroxyapatites, e.g. ApaPore®, Allogran®, are regarded as non-absorbable. – Carbonated apatites, e.g. Norian®, BoneSource®, Calcibon®, resorb in an osteogenic environment. – Available as a mixture of chips, blocks and injectable cement. – Clinically, calcium phosphates are used for: • Filling bone tumour and cyst defects. • Filling bone voids following open fracture surgery. • Augmenting available autologous bone graft. • Back-fill for iliac crest after autologous bone graft harvest. • Augmentation of the facial skeleton. • Calvarial remodelling: • Inlay remodelling is replacement of full thickness skull. • Onlay remodelling is replacement of part of the outer skull. – Radiesse® is an injectable filler composed of calcium hydroxyapatite particles in a gel carrier. – Given its low solubility it can theoretically persist for years. – Appears radiopaque on X-rays. Wound dressings • There is little concrete evidence that any one dressing is better than another. • The ideal wound dressing should: 1 Protect the wound physically and microbiologically. 2 Be non-toxic and non-allergenic. 3 Maintain high wound humidity while removing excess exudate. 4 Allow gaseous exchange. 5 Remove necrotic material. 6 Promote epithelialisation. 54 Chapter 1 7 Promote granulation. 8 Ensure atraumatic application and removal. 9 Be inexpensive with long shelf life. Classification Low-adherent dressings • Allow exudate to pass through into a secondary dressing. • Further classified as: ∘ Tulles – Open-weave cloths soaked in soft paraffin (Jelonet® ) with or without chlorhexidine (Bactigras® ) ∘ Textiles – Atrauman®, NA Ultra®, Mepitel® ∘ Perforated multilayered plastic films – Telfa™, Melolin™. Semipermeable films • Permeable to gases and vapour. • Impermeable to liquids and bacteria. ∘ Omiderm™ is a polyurethane film without adhesive backing. ∘ Opsite® and Tegaderm™ are adhesive polyurethane films. Hydrogels • Composed of insoluble polymers with up to 96% water content. • Donate water to the wound surface and maintain a moist environment. ∘ Wound rehydration facilitates natural autolysis of non-viable tissue. • Not used on gangrene – usually kept dry to reduce infection risk. • Examples: Aquaform®, Intrasite™, GranuGel®. Hydrocolloids • Main components include sodium carboxymethylcellulose, gelatin, elastomers. • Forms a gel on the wound surface, maintaining a moist environment. ∘ Examples: Granuflex®, DuoDERM®. • Hydrocolloid fibres are now available, referred to as Hydrofiber® dressings. • Wound exudate converts the dry fibres to a soft coherent gel sheet. ∘ Examples: Aquacel®, Versiva®. Alginates • Derived from a brown seaweed. • Some also contain calcium, which activates the clotting cascade. • They are absorbent and become gelatinous after absorbing moisture. • Tend to adhere to non-exudating wounds, causing pain on removal. • Examples: Sorbsan®, Kaltostat®. Synthetic foams • Manufactured from either polyurethane or silicone. General Principles • • • • 55 Usually used in deep wounds. Conform to cavities, obliterate dead space. Suitable for heavily exudating wounds. Examples: Lyofoam®, Allevyn®, Cavi-Care®. Negative pressure wound therapy (NPWT) • Reports claim that application of suction improves wound-healing rates. ∘ There are no randomised controlled trials to support these reports. • Possible mechanisms of action include: ∘ Direct suction effect, pulling the wound inward. ∘ Increased rate of angiogenesis and granulation tissue formation. ∘ Reduced concentration of tissue metalloproteinases. ∘ Decreased bacterial contamination. ∘ Decreased interstitial fluid content of the wound. • Suction is applied to the wound in the following manner: 1 The wound is covered with an open-cell sponge or open-weave gauze dressing, containing the end of a suction tube. 2 The wound is sealed with a semipermeable, adhesive film. 3 Suction is applied to the wound from a specifically designed machine. • Suction pressures are usually set around 120 mmHg for acute wounds; 50–70 mmHg for chronic wounds. • Intermittent suction (e.g. 5 minutes on, 2 minutes off) has been shown to increase the rate of granulation tissue formation. • NPWT has been used to improve skin graft take. Contraindications • Malignancy within the wound • Untreated osteomyelitis • Unexplored fistulae • Where there is necrotic tissue or eschar – this should be debrided first. • Use on ischaemic wounds may increase the zone of necrosis. Sutures and suturing Suturing • Skin edges should be everted. • This results in: ∘ Better dermal apposition ∘ Improved healing ∘ A finer final scar. • Most wounds are closed by first opposing skin edges with dermal sutures. ∘ Reduces tension on subsequent cutaneous sutures. ∘ Limits stretching of the wound. 56 Chapter 1 Suture materials • Absorbable or non-absorbable • Synthetic or natural • Braided or monofilament. Absorbable sutures Catgut • Derived from either bovine serosal or ovine submucosal intestinal layers. • Elicits significant inflammatory response. • Absorption is unpredictable: ∘ Loses strength by 8–9 days. ∘ Absorbed by 2–3 months. ∘ Absorption rate decreases if the suture is chromatised (chromic catgut). • Not used frequently in the UK nowadays, but worldwide it is used for: ∘ Mucosal suture ∘ Dermal suture in the face ∘ Skin suture in children. Polyglycolic acid • Dexon™ is a synthetic suture of polyglycolic acid. • Degraded by hydrolysis. • Loses strength by 21 days; absorbed by 90 days. Polyglactin 910 • Vicryl® is a braided synthetic suture of polyglactin 910. • Loses strength by 21 days; absorbed by 90 days. • Its braided nature may make it more prone to bacterial colonisation than monofilament alternatives. • Can provoke a significant inflammatory reaction. • Vicryl Rapide is related to Vicryl, but loses its strength after 7–10 days. • Vicryl Plus is coated with Triclosan, an antibacterial and antifungal. Poliglecaprone 25 • Monocryl® is a monofilament synthetic suture composed of poliglecaprone 25. • Absorption characteristics similar to Vicryl. • Its monofilament composition may make it less prone to bacterial colonisation. • Monocryl Plus is coated with Triclosan. Polydioxanone sulphate (PDS) • PDS® II is a monofilament synthetic suture. • Absorbed more slowly than Vicryl, Monocryl, or Dexon. • Within 6 weeks of insertion: ∘ 3-0 PDS loses 40% of its tensile strength. ∘ 4-0 PDS loses 65% of its tensile strength. • Absorbed by 6 months. General Principles 57 • Primarily used as a dermal suture in areas prone to stretched scars. • Also available as PDS Plus with Triclosan. Non-absorbable sutures • Non-absorbable sutures are generally used as: ∘ Cutaneous stitches, which require removal. ∘ Deep stitches to provide permanent tissue fixation. • Non-absorbable sutures can be natural or synthetic. Natural • Silk • Cotton Synthetic • Polyamide – Nylon • Polypropylene – Prolene® • Polyester – Ethibond®, Novafil® • PTFE – Gore-Tex • Stainless steel. Tissue expansion • Tissue expansion, by techniques such as neck lengthening, has been practised since ancient times. • In 1957, Neuman described tissue expansion for therapeutic purposes. • Since then, it has been popularised by authors such as Radovan and Austad. Mechanisms • 70% of tissue gain is due to stretch (mechanical creep) and 30% due to growth (biological creep). • Tissue subjected to constant strain relaxes – less force is required to keep it stretched. ∘ This is known as stress relaxation. • Creep is the time-dependent plastic deformation of any material in response to constant stress. • Mechanisms of tissue creep: ∘ Disruption of elastin fibres ∘ Re-alignment of collagen ∘ Fluid displacement ∘ Migration of local tissue. Changes • Tissue-expanded skin is characterised by these changes: Epidermis • Thickness usually increases but can remain the same as unexpanded skin. • Mitotic rate of the basal layer is increased, suggesting new tissue is generated. 58 Chapter 1 Dermis • Thickness decreases. • Collagen fibres realign along the lines of tension. Skin appendages and nerves • Become increasingly separated from one another. • Hair density is therefore reduced. Subcutaneous tissue, muscle and bone • Pressure effects of the expander may cause localised atrophy of tissue. Blood supply • Vascularity of expanded flaps is superior to non-expanded controls. ∘ Mechanical force improves vascularity of expander capsule and dermis. ∘ Perfusion studies show increased axiality and total capillary blood flow. • Including the expander capsule in the flap harnesses this enhanced blood supply. • Improvement in flap length survival is at least equivalent to, if not better than, that achieved with conventional delay techniques. • Expanded flaps are therefore considered to be delayed. Microscopic appearance of the expander capsule • Pasyk describes four zones of a silicone expander capsule: 1 Inner zone: fibrin layer containing macrophages. 2 Central zone: elongated fibroblasts and myofibroblasts, pressed between thick bundles of collagen fibres oriented parallel to the expander surface. 3 Transitional zone: loose collagen fibres and a few blood vessels. 4 Outer zone: an established vascular layer and loose collagen fibres. Advantages • Reconstruction with tissue of colour and texture similar to that of the defect. • Reconstruction with sensate skin containing skin appendages. • Limited donor-site deformity. Insertion and placement of expanders • Can be inserted through a variety of incisions. ∘ These may be local or remote. • A remote, radially orientated incision has the lowest complication rate. • Can be placed above or below the fascia. ∘ Subcutaneous placement is usually preferred in the face and trunk. ∘ Subfascial placement is usually preferred in the forehead and scalp. • Complication rates in the limb are reportedly higher than in non-limb sites. General Principles 59 • If placed in soft, mobile tissue such as the abdomen, the filling port should be placed over firm tissue such as rib or iliac crest to facilitate filling. Contraindications • Ideally, tissue expanders should not be inserted: ∘ In the vicinity of an immature scar ∘ In the presence of infection ∘ In irradiated tissue ∘ Under skin grafts. Design of expanders • Expandable, saline-filled silicone bags. • They differ from one another in the following ways: Shape • Oval • Rectangular • Round • Square • Crescentic (croissant-shaped) ∘ May result in shorter donor defects with minimal dog ears. ∘ Expansion principally occurs over the central portion of the expander. • Custom made. Size • Base dimensions • Projection when inflated. Location of the port • Integrated ports form part of the shell of the expander. • Remote ports are attached to the expander by a filling tube. ∘ Can be placed subcutaneously or externally. Envelope composition • The shell of an expander can have a smooth or textured surface. • The shell is usually of uniform thickness and compliance. ∘ Variations in thickness and compliance produce preferential expansion in certain directions. – Isotropic expanders expand in all directions. – Anisotropic expanders expand in certain controlled directions. • Expanders may or may not have a stiff backing bonded onto their shell. 60 Chapter 1 Self-inflating expanders • Have no port; attractive to use in children because they avoid repeated needling. • Contain a hypertonic compound; they gradually fill through osmosis. • Early expanders were filled with hypertonic saline. ∘ Expansion was uncontrolled and caused widespread tissue necrosis. • Newer generation expanders, e.g. Osmed®, contain a hydrogel of vinylpyrrolidone and methylmethacrylate. ∘ The size and number of holes in the shell control expansion rate. ∘ Despite this, high complication rates have been reported. Timing and length of expansion Intra-operative expansion • Sustained traction applied to tissue by skin hooks or other instruments. • Tissue expansion with a Foley catheter. • Sure-Closure™ skin stretching devices. Rapid expansion • Rationale: most tissue creep and growth occurs in the first 2 days. • Some therefore recommend expander inflation every 2–3 days. Conventional expansion • Most expanders are inflated weekly. • Allows sufficient time for tissues to stabilise between expansions. • Expansion is stopped when the amount of tissue gained is sufficient for reconstruction. • This can be estimated by: ∘ Recording the dimensions of tissue over the expander from fixed points before it is inflated. ∘ Comparing these measurements to the dimensions after inflation. ∘ Comparing the tissue gain to the dimensions of the defect. Complications • Minor complications do not result in termination of the procedure. • Major complications do result in termination of the procedure. • Complications include: ∘ Haematoma ∘ Infection ∘ Exposure of the expander ∘ Extrusion of the expander ∘ Pain ∘ Neurapraxia ∘ Pressure effects on surrounding tissue General Principles ∘ ∘ 61 Accidental perforation by missing an integrated filling port Flipping of a remote filling port, making filling impossible. Lasers • Acronym of Light Amplification by Stimulated Emission of Radiation. Laser physics Radiation • The visible part of the electromagnetic spectrum consists of light with wavelengths from 400 nm (blue) to 700 nm (red). • Invisible wavelengths sit either side of the visible spectrum: ∘ Shorter wavelengths (higher energy) – ultraviolet, X-rays, γ-rays. ∘ Longer wavelengths (lower energy) – infrared, microwaves, radio waves. • Different lasers use light of different wavelengths to mediate their effects. Stimulated emission • A molecule or atom in its resting state is composed of a nucleus and circulating electrons in their ground state. • Adding energy to an atom causes the electrons to shift into a higher energy, unstable orbit. • As an excited electron falls back to its more stable ground state, it releases the excess energy as a photon of light. ∘ The photon has a wavelength specific to that atom or molecule. • If that photon collides with another excited electron, that electron returns to its ground state, releasing another photon. • The original photon is not absorbed, so there are now two photons of the same frequency. • Importantly, these photons are in phase: their waveforms reinforce each other. • This process is stimulated emission. Light amplification • As photons hit other excited electrons, more photons are released and the light energy increases. • For the laser to work, a population inversion is necessary. • Population inversion occurs when the majority of the molecules in the laser exist in an excited state. Structure of a basic laser • Laser requires three things: 1 An external power source, e.g. flash lamp, diode, radio frequency emission. 62 Chapter 1 2 A lasing medium, which can be: – Solid, e.g. ruby crystal, Neodymium:YAG, Erbium:YAG, KTP. – Gas, e.g. CO2 , argon. – Liquid, used in dye lasers. 3 Reflective mirrors at each end of a laser tube. – Only photons that hit the mirrors directly are reflected back into the lasing medium. – This creates an increasing number of photons that travel back and forth between the mirrors, parallel to the tube. – To allow light to escape from the tube, one mirror is only partially reflecting. – The resulting light is the output beam of the laser, which can be focused with a lens. Q-switching • Q-switching is an important exception to this basic model. • Rather than a partially reflecting mirror, a Q-switched laser uses two fully reflective mirrors. • High power is generated because of a large population inversion, and the fact that stimulated emission of light cannot escape. • The Q-switch dumps the entire contents of the chamber, producing a short pulse of high intensity. ∘ A normal laser releases its energy in the same way as water escapes from a bath through the plughole. ∘ A Q-switched laser releases its energy in the same way as if one could suddenly remove the bottom of the bath, dumping all the water at once. Properties of laser light 1 2 3 • Collimated: laser light diverges very little as it travels. Monochromatic: laser light has only one wavelength. Coherent: the peaks and troughs of laser light waves are in phase. These properties make laser light intense and powerful. Laser interaction with tissue • Lasers react with tissues through their thermal, chemical, or photoacoustic effects. • When laser light hits tissue it can be: ∘ Reflected ∘ Scattered ∘ Absorbed ∘ Transmitted. • It is the absorbed light that causes biological effects, both desirable and undesirable. • A specific wavelength of laser light will be preferentially absorbed by a target chromophore within tissue. ∘ Common biological chromophores: water, haemoglobin, melanin. General Principles 63 Thermal effects • Occur by three different mechanisms: 1 Coagulation – Light absorbed by a target chromophore is converted to heat. – Coagulation occurs when tissue containing the chromophore reaches 60 ∘ C. 2 Vaporisation – Tissue heated to 100 ∘ C will vaporise. 3 Selective photothermolysis – Thermal damage is induced in a tissue target that absorbs light of a specific wavelength. – Selectivity occurs when the exposure time of the tissue to laser light is shorter than the cooling time, or thermal relaxation time (TRT). – TRT is defined as the time taken by a specific volume of tissue to dissipate 51% of the energy absorbed. – Heat energy dissipated to surrounding non-target tissues can cause collateral effects. – Once the TRT has elapsed, another pulse can be delivered to the target without generating thermal damage to surrounding non-target tissue. Cooling • Cooling protects superficial non-target tissue, such as epidermis, from collateral thermal damage. • Allows higher energy levels to be used. • Four basic methods of skin cooling: 1 Bulk pre-cooling – epidermis and dermis cooled prior to pulse delivery. 2 Dynamic pre-cooling – epidermis cooled prior to pulse delivery. 3 Parallel cooling – epidermis cooled during pulse delivery. 4 Post-cooling – epidermis and dermis cooled after pulse delivery. • Examples: cryogen spray, gliding window handpiece, cold handpiece, cold air, cooling gel. Laser variables • Lasers are controlled by four variables: 1 Wavelength – Measured in nanometres (nm); specific to the lasing medium. 2 Power – Measured in Watts (W) or Joules per second (J/s). 3 Spot size – Measured in cm2 . Depends on focal length of the lens. – Larger spot sizes show less scatter and penetrate deeper. 4 Duration of action. – Also called pulse width; measured in fractions of a second. 64 Chapter 1 • The latter three variables are used to calculate two further values: ∘ Power density: the energy delivered per unit area of incident tissue (W/cm2 ). ∘ Fluence: the product of power density and exposure time (J/cm2 ). Clinical applications of laser Indication Chromophore Laser Vascular lesions Oxyhaemoglobin Skin resurfacing Water Pigmented lesions Melanin Hair removal Melanin Tattoo removal Black/blue/green Black/blue/green Black Red/orange/brown Pulsed Yellow Dye Laser KTP Nd:YAG IPL* Er:YAG CO2 Diode Ruby IPL* Alexandrite Diode Nd:YAG Ruby IPL* Q-switched ruby Q-switched alexandrite Q-switched Nd:YAG Q-switched Nd:YAG Wavelength (nm) 585 532 1064 N/A 2940 10,600 800 694 N/A 755 800 1064 694 N/A 694 755 1064 532 *IPL, intense pulsed light (not laser light) – Xenon flashlamps generate multiwavelength non-coherent light that is modulated by a series of filters. KTP, potassium titanyl phosphate; YAG, yttrium aluminium garnet; Nd, neodymium; Er, erbium. Laser safety • In the United Kingdom, this is legally enshrined in the Control of Artificial Optical Radiation at Work Regulations 2010. ∘ Based on requirements of the International Electrotechnical Commission. • Laser misuse can cause unintended severe and irreversible damage to the retina. ∘ This damage may go unnoticed because wavelengths outside the visible spectrum will not invoke a blink reflex. • Lasers can also cause cutaneous burns; some represent a fire hazard. • Lasers are classified from Class 1 to 4 based on wavelength and maximum power output. ∘ Medical lasers are Class 4 (severe hazard for eyes and skin). • Main facets of laser safety: ∘ Risk awareness through risk assessment. ∘ Watches, jewellery and other reflective surfaces should be covered. General Principles ∘ ∘ ∘ ∘ ∘ 65 Eye protection should be worn by everyone in the room. The laser key should be stored away from the laser machine. Treatment around the eyes may require corneal eye shields. A laser-safe endotracheal tube should be used when using CO2 laser. Lasers that create a significant laser plume, such as the CO2 laser, should be used with a plume evacuator to prevent potential transmission of live virus particles into the airway of treating personnel. Local anaesthesia • Local anaesthetics produce reversible loss of sensation in a circumscribed area of the body. • They prevent generation and conduction of nerve impulses by blocking voltage-gated sodium channels. Classification • Local anaesthetics are classified by their molecular structure: 1 Amides – Tend to have an ‘i’ in the first half of their generic name. – Examples: lignocaine, bupivacaine, prilocaine. – Metabolised in the liver; rarely cause anaphylaxis. 2 Esters – Tend not to have an ‘i’ in the first half of their name. – Examples: procaine, tetracaine, chloroprocaine, amethocaine. – Degraded in plasma by pseudocholinesterase. – More likely to cause anaphylaxis because they are metabolised to para-amino benzoic acid (PABA), which is highly allergenic. Pharmacokinetics • Local anaesthetic binds to voltage-gated sodium channels in its ionised state. • Acidifying local anaesthetic solutions to produce more ionised molecules does not increase the degree of nerve block as expected. ∘ This is because charged ions cannot cross cell membranes of the epineurium and perineurium. ∘ The proportion of local anaesthetic in its non-ionised state is what determines rate of diffusion across nerve cell membranes, and therefore the speed of onset of anaesthesia. • The pKa (acid dissociation constant) is the pH at which the ionised and non-ionised forms of an acid are in equilibrium. ∘ The pKa value is constant for any given compound. • This explains why local anaesthetics with a pKa close to that of human tissue pH (7.4) have a rapid onset, such as lidocaine, pKa 7.6. • By comparison, the slower acting bupivacaine has a pKa of 8.1. • Local anaesthetics fail in the presence of infection or inflammation because localised hypoxia produces an acidic tissue environment. • Alkalinisation of local anaesthetic solution with sodium bicarbonate has been shown to speed onset and enhance its effect. 66 Chapter 1 • Speed of onset is also related to diffusability of local anaesthetic through non-neural tissue. • More lipid soluble molecules, e.g. bupivacaine, have higher affinity for axons, and therefore slower onset and longer duration of action than more hydrophilic molecules, e.g. lidocaine. • Duration of action is influenced by the degree of vasodilatation caused by the local anaesthetic. ∘ All local anaesthetics except cocaine are vasodilators. • Quoted maximum safe doses are not universally accepted because: ∘ Patients vary both in body habitus and metabolism. ∘ Rates of absorption vary in different tissues, depending on the blood flow. ∘ Body weight gives no indication of lean tissue mass. Epinephrine • Epinephrine is added to local anaesthetics to cause vasoconstriction. • Reduces local anaesthetic absorption, therefore prolonging block duration and reducing toxicity. • Maximum safe dose of epinephrine is controversial. ∘ A safe guideline amount is 4 μg/kg. • Commonly used in combination with local anaesthetics at concentrations of 1:200,000. ∘ In fact, doses as low as 1:1,000,000 are probably just as effective. • The maximum dose should be reduced in cases of serious ischaemic heart disease, thyrotoxicosis and hypertension. • There is no evidence that using concentrations of epinephrine up to 1:100,000 in digital nerve blocks causes digital infarction. Common local anaesthetics Lidocaine • • • • • Also called lignocaine or xylocaine. Used in clinical practice for almost 60 years. Rapid onset; relatively short duration. Available as 1% and 2% solutions. Maximum safe dose: 3 mg/kg plain; 7 mg/kg with epinephrine, but see Chapter 9, ‘Liposuction’. Bupivacaine • Used in clinical practice for more than 40 years. • Long duration of action (up to 24 hours in some cases). • Adding epinephrine decreases toxicity by delaying drug absorption, but has minimal effect on block duration. • It is particularly cardiotoxic; should never be used in Biers blocks. • Available as 0.25% and 0.5% solutions. • Maximum safe dose: 2 mg/kg plain; 2 mg/kg with epinephrine. General Principles Levobupivacaine • Relatively new agent; essentially the same as bupivacaine. ∘ Bupivacaine is a racemic mixture of R and S enantiomers. ∘ Levobupivacaine contains the S enantiomer only. • It is less cardiotoxic than bupivacaine. • Available as 2.5 mg/ml and 5 mg/ml solutions. ∘ For spinal anaesthesia, 7.5 mg/ml preparations may be used. • Maximum safe dose: 3 mg/kg plain. There is little data to support this. Prilocaine • Closely related to lidocaine. • More rapidly metabolised and hence less toxic. • Can cause methaemoglobinaemia in high doses (>600 mg). ∘ Blue skin discolouration and false pulse oximeter readings. ∘ Usually benign and resolves within a couple of hours. ∘ Treatment is methylene blue 1 mg/kg, given IV over 5 minutes. • Prilocaine is the drug of choice for Biers block. • Available as a 1% solution. • Maximum safe dose: 6 mg/kg plain; 9 mg/kg with epinephrine. Topical anaesthesia • Used to minimise discomfort prior to venesection or superficial skin treatment. Ametop® • Contains 4% tetracaine. • Takes 30–45 minutes to take effect. EMLA® • Acronym for Eutetic Mixture of Local Anaesthetic. • Consists of 2.5% lidocaine and 2.5% prilocaine. • Takes 1–5 hours to take effect. LMX 4® • Contains 4% lidocaine. • Takes 30 minutes to take effect. Dose calculation • • • • Local anaesthetic concentration is usually expressed as a percentage. In contrast, maximum safe dose is expressed as milligram per kilogram. It is therefore helpful to convert percentage to milligram per millilitre. To do this for local anaesthetics, multiply the percentage by 10. ∘ Example: lignocaine 1% is 10 mg/ml; bupivacaine 0.25% is 2.5 mg/ml. 67 68 Chapter 1 • Epinephrine concentrations are expressed as ratios, such as 1:1000. • To calculate milligram per millilitre from a ratio, first convert the ratio to a percentage: ∘ If 1:100 is 1%, then 1:1000 is 0.1%. • Once you have a percentage, you can multiply this by 10 to get milligram per millilitre. • Therefore, 1:1000 epinephrine is 1 mg/ml. Toxicity • Rare, but may occur due to: ∘ Accidental intravascular administration ∘ Administration of an excessive dose. • Toxicity can manifest several hours after administration. • Primarily affects central nervous system (CNS) and cardiovascular system (CVS). CNS toxicity • Symptoms: ∘ Dizziness and light-headedness ∘ Disorientation ∘ Circumoral paraesthesia ∘ Difficulty focusing with the eyes ∘ Tinnitus. • Signs: ∘ Shivering/muscle twitching, progressing to ∘ Generalised tonic clonic seizures, progressing to ∘ Coma. CVS toxicity • Occurs at higher doses than CNS toxicity: ∘ Sinus bradycardia due to blockade of the spontaneous pacemaker. ∘ Can progress to sinus arrest. ∘ Depression of cardiac contractility. • Low level toxicity causes vasoconstriction. • Higher level toxicity causes vasodilatation. • Bupivacaine can cause refractory ventricular fibrillation. Management • The Association of Anaesthetists of Great Britain & Ireland published guidelines in 2010. • Immediate actions: ∘ Stop injecting local anaesthetic. ∘ Call for help. ∘ ABCs with 100% oxygen. ∘ Control seizures by conventional means. • If there is circulatory arrest, commence CPR and treat arrythmias conventionally (but not with lidocaine). General Principles 69 • Give 1000 ml of 20% lipid emulsion, such as Intralipid®. ∘ Using propofol, which is supplied as a lipid emulsion, is not a safe substitute for Intralipid due to the significant cardiovascular depression it causes. • Recovery from local anaesthetic-induced cardiac arrest may take over an hour. Microsurgery History • Alexis Carrel described the triangulation technique of blood vessel repair in 1902. ∘ He was awarded a Nobel Prize in 1912. • Ronald Malt and Charles McKann described the first successful arm replantation in 1962. • Nakayama, a Japanese cardiothoracic surgeon, reported the first true series of microsurgical free tissue transfers using vascularised intestinal segments for oesophageal reconstruction in 1964. • Komatsu and Tamai reported the first successful digital replant in 1968. • Cobbett first reported free toe-to-hand transfer, performed at the Queen Victoria Hospital, in 1968. • Daniel & Taylor and O’Brien & associates independently reported use of the free groin flap for leg reconstruction in 1973. Pathophysiology of vessel healing Vessel healing following anastomosis • • • • • A thin layer of platelets forms at the anastomosis site immediately after repair. These platelet aggregations disappear between 24 and 72 hours. Pseudo-intima forms at the anastomosis site within 5 days. New endothelium covers the anastomosis site within 1–2 weeks. Factors contributing to intimal damage and anastomotic thrombosis: ∘ Rough vessel dissection ∘ Desiccation of the vessels ∘ Diathermy close to the vessel ∘ Prolonged vasospasm ∘ Application of vascular clamps with closing pressures >30 g/mm2 ∘ Use of large needles ∘ Repeated needle stabs ∘ Partial-thickness suture bites ∘ Unequal spacing of sutures ∘ Loose sutures ∘ Excessively tight sutures ∘ Too many sutures ∘ Tension across the suture line. Thrombus formation • Platelets do not normally adhere to intact endothelium. 70 Chapter 1 • Collagen exposure within the media and adventitia of vessels triggers platelet aggregation and degranulation. Drugs that limit thrombus formation Heparin • A single dose of IV heparin may be given at the time of anastomosis. • Some argue that the risk of bleeding outweighs any potential benefit. Dextran • A polysaccharide available in molecular weights of: ∘ 40 kDa (Dextran 40) ∘ 70 kDa (Dextran 70) • Dextran was initially used as a volume expander. • Subsequently, it was noted to have antiplatelet and antifibrin properties. • Animal studies show improved anastomotic patency with dextran. • Side effects include anaphylactoid reactions and renal impairment. Aspirin • Inhibits platelet aggregation. Proteolytic enzymes • Used to dissolve thrombus: ∘ Streptokinase ∘ Urokinase ∘ Tissue plasminogen activator (t-PA). • Routine use of anticoagulants or fibrinolytic agents is controversial. • If thrombosis occurs, the anastomosis should be explored. ∘ These patients should probably receive anticoagulant or fibrinolytic therapy. • For salvage of repeated thrombosis, fibrinolytic therapy should be instituted. Reperfusion injury • Free radicals are used against bacteria in normal circumstances. ∘ Examples: superoxide anion radical O2 −, hydroxyl radical ⋅HO. • Free radicals accumulate when a flap is devascularised. • When a flap is ‘reperfused’ after a period of ischaemia, the following occur: ∘ Endothelial cell damage ∘ Endothelial swelling ∘ Increased capillary permeability. • Skin and subcutaneous tissue tolerate: ∘ Warm ischaemia of 6 hours ∘ Cold ischaemia of 12 hours. • Muscle is intolerant of ischaemia and develops irreversible changes after: ∘ 3 hours of warm ischaemia time ∘ 8 hours of cold ischaemia time. • Bowel is extremely intolerant of ischaemia. General Principles 71 The no-reflow phenomenon • Characterised by failure of tissue perfusion despite adequate arterial input and venous drainage. • Believed to occur due to: ∘ Swelling of vascular endothelium ∘ Platelet aggregation ∘ Leakage of intravascular fluid into the interstitial space. • Can be treated with: ∘ Fibrinolytic drugs ∘ Lidocaine ∘ Heparin ∘ NSAIDs, which act by inhibiting cyclooxygenase (COX). Equipment Magnification • Some prefer loupe magnification to repair larger vessels. • Small vessels are best repaired with an operating microscope. • The microscope should be able to magnify between ×6 and ×40. Instruments • Forceps – four pairs of jeweller’s forceps • Vessel dilators • Microdissecting scissors • Needle holders • Single and double microvascular clamps of varying sizes. ∘ They should have a closing pressure of <30 g/mm2 . Irrigating solutions • Heparin dissolved in Hartmann’s or saline to a concentration of 100 units/ml. • Topical papaverine, verapamil, or lidocaine to relieve vessel spasm. Sutures • Monofilament 8, 9, 10 and 11-0 nylon. • Half-circle or compound-curve atraumatic needles of 50–130 μm diameter. Coupling devices • Commercially available devices that may save time over hand-sewing. • Mostly used for end-to-end venous anastomosis. Technique • Acland described five factors that influence microvascular patency: 1 Surgical precision 2 Vessel diameter 3 Blood flow into the anastomosis 72 Chapter 1 4 Tension of the anastomosis 5 Use of anticoagulants or thrombolytic agents. • Key steps for successful microvascular free tissue transfer: 1 Obtain adequate access. – Do not operate down a hole. 2 Operate in a dry field. 3 Position and secure the flap before starting the anastomosis. – The flap should be tacked into position before starting the anastomosis. – Position the pedicle with care, ensuring it is: • The correct length to lie at the anastomosis site without tension • Not twisted or kinked • Not compressed. 4 Prepare the vessels for anastomosis by stripping the adventitia. 5 Flush the vessel with heparin solution. – Excessively powerful irrigation can cause intimal trauma. 6 Limit vessel distension with the dilating forceps. – Excessive dilatation causes intimal tears or vessel spasm. 7 Perform a forward-flow test prior to anastomosis: – Proximal arterial flow is tested by releasing the clamps on the artery. 8 Never start the anastomosis until you are happy with the setup. • Points of technique: ∘ The needle should be held halfway along its length. ∘ The most difficult sutures are generally inserted first. ∘ The needle should be accessible within the visual field when tying knots. – This facilitates its retrieval for the next stitch. ∘ Triangulation, bisecting and posterior wall first techniques can be used. ∘ Interrupted or continuous sutures can be used. ∘ Airborne tying techniques avoid suture ends getting stuck to surrounding tissues. ∘ The suture should not be tied if it may have caught the posterior wall. ∘ Limit vessel handling after anastomosis as this can result in spasm. Post-operative management • Patients should be ‘warm, wet and comfortable’: ∘ A warm room, often with a warming blanket during surgery and transfer. ∘ Well perfused with good urine output and normal blood pressure. – Thresholds for blood transfusion should be set. – Anaemia in the early post-operative period may be dilutional. ∘ Analgesia, often with regional anaesthetic blocks or patient-controlled analgesia. Post-operative monitoring Clinical parameters • Colour • Temperature • Tissue turgor General Principles 73 • Capillary return • Bleeding on pinprick. Doppler recordings • Commonly used. • Can record arterial or venous flow. • May give false-positive readings by detecting flow in deep vessels. • Implantable venous Doppler probes are available: ∘ An ultrasonic probe is mounted on a silicone cuff and wrapped around the venous pedicle. Laser Doppler • Records blood flow in a small area. • Scans blood flow over a large area. • Measures changes in the Doppler shift of light. ∘ Produced by movement of macromolecules within vessels. • Depth of penetration is limited to 1.5 mm. Near-infrared spectroscopy • Similar to laser Doppler. • Uses longer wavelength of light; consequently penetrates deeper. Temperature measurement • The flap’s temperature can be measured accurately with a probe. • Temperature difference >2 ∘ C between flap and body core indicates possible ischaemia. • Useful for monitoring digital replants. Pulse oximetry • Measures oxygenation of haemoglobin. • Useful for monitoring digital replants. Impedance monitoring • Measures impedance between two electrodes placed on the flap. Plethysmography • Measures changes in flap volume. • Increased readings indicate flap congestion. Intravenous fluorescein infusion • Demonstrates blood flow within the flap. • A test dose is given intravenously, followed by a dose of 15 mg/kg. • The flow of fluorescein can be observed under a Wood’s lamp. Management of a non-flowing anastomosis • A common question in plastic surgery examinations. 74 Chapter 1 • Absence of flow through a technically sound anastomosis is managed as follows: ∘ Apply lidocaine to the anastomosis and place a warm, wet gauze over it. ∘ Ask the anaesthetist to haemodynamically optimise the patient by ensuring: – They are warm and well hydrated. – They are not receiving vasoconstricting drugs. – The blood pressure is raised. • Do not disturb the anastomosis for at least 15 minutes. • If flap perfusion remains inadequate, inspect the pedicle for twisting or compression. • If the anastomosis is not patent or has thrombosed, redo the anastomosis. • A Fogarty catheter can be carefully used for thrombectomy of recipient vessels. ∘ Avoid excessive manipulation of a thrombosed anastomosis. – This may send showers of emboli into the flap. • If the anastomosis repeatedly thromboses, consider thrombolytic treatment: ∘ Streptokinase can be administered as Streptase® ∘ Give 250,000 international units (IUs) of Streptase dissolved in normal saline as a loading dose over 30 minutes. ∘ This is followed by a maintenance dose of 100,000 IUs per hour. • Contraindications to streptokinase treatment include: ∘ Administration of streptokinase within the previous 6 months ∘ Previous stroke ∘ Mitral valve disease ∘ Active bleeding. • Given the risk of systemic complications, administration of Streptase can be limited to the flap by injecting directly into the pedicle artery and allowing the venous side to bleed out. Leech therapy • The leech species Hirudo medicinalis can be used to improve venous drainage from congested flaps. • Once latched on, leeches feed for 30–60 minutes; can consume up to 10 times their body weight. • Leeches detach themselves when feeding is complete, leaving a characteristic ‘MercedesBenz’-shaped bite mark. ∘ Do not pull them off or their teeth will be left behind, causing infection. ∘ Forceful removal can also cause regurgitation of gut flora, causing infection. • Once fed, leeches are destroyed humanely in alcohol and never reused. • Prolonged bleeding may occur due to the anticoagulant action of hirudin in leech saliva. ∘ This can be controlled with simple pressure. ∘ Blood loss should be monitored for the duration of treatment. • Leech bites may be contaminated with Aeromonas hydrophila – an oral commensal. ∘ Antibiotic prophylaxis with a quinolone such as ciprofloxacin is recommended. Haemostasis and thrombosis • Haemophilia is a tendency to bleeding. • Thrombophilia is a tendency to thrombosis. • Both may be inherited or acquired. General Principles 75 The coagulation cascade • Two pathways culminating in fibrin formation – the basis of clot and thrombus. • The cascade is not linear as shown here – there are many feedback loops. ∘ Activation of one factor can activate many other factors. Coagulation cascade INTRINSIC PATHWAY Surface contact with collagen or activated platelets XII a = activated PL = cell membrane phospholipid Ca++ = ionic calcium TF = tissue factor XIIa XI EXTRINSIC PATHWAY XIa TF:VIIa IX Tissue damage IXa (VIII, PL, Ca++) X Xa FINAL COMMON PATHWAY X (V, PL, Ca++) XIII Prothrombin Thrombin XIIIa Fibrinogen Fibrin Stable fibrin clot Intrinsic pathway • Triggered by collagen or activated platelets, which activate factor XII. • Activation cascades eventually convert factor X into activated factor X (Xa). • Evaluated by the activated partial thromboplastin time (APTT). Extrinsic pathway • The primary pathway for initiation of coagulation. • Tissue damage activates factor VII, which converts factor X into Xa. • Evaluated by the prothrombin time (PT). Final common pathway 1 Conversion of prothrombin to thrombin by Xa. 2 Conversion of fibrinogen to fibrin by thrombin. 3 Thrombin also activates factor XIII, which converts fibrin monomers into stable polymers. 76 Chapter 1 Anticoagulants • Used to prevent thrombus formation in the venous circulation. • In slower circulations, thrombi predominantly consist of platelets and red cells enmeshed in fibrin. Heparin • Naturally occurring GAG produced by mast cells. • It (indirectly) has anti-thrombin and anti-Xa activity. • Used to achieve immediate anticoagulation. • Treatment is monitored by the APTT ratio, aiming for 2–2.5× normal. • Stopped 6 hours prior to surgery; restarted 6–12 hours after surgery. • Reversal with protamine sulphate is rarely required. • Use for 4 days or more is associated with heparin-induced thrombocytopenia (HIT) in some patients. Low-molecular-weight heparins (LMWH) • Examples: dalteparin, enoxaparin, tinzaparin. • Used for prophylaxis and treatment of venous thromboembolism and unstable coronary disease. • More convenient to administer and has less risk of HIT than unfractionated heparin. • Monitoring of its anti-factor Xa activity is not routinely required. Warfarin • Coumarin derivative; inhibits vitamin K epoxide reductase. • This depletes intrahepatic vitamin K, which is a necessary cofactor for synthesis of clotting factors II, VII, IX and X. • Monitored using the International Normalised Ratio (INR), based on the PT. • Warfarin is stopped pre-operatively unless the risk of thromboembolism is high. ∘ Partial reversal usually occurs after 3 days; complete reversal after 5 days. Platelets • Platelets survive for 7–10 days. • They are activated by a myriad of agonists, including: ∘ Collagen ∘ Tissue factor ∘ ADP ∘ vWF. • These converge on activation of a fibrinogen receptor: glycoprotein IIb/IIIa. • Breakdown of arachidonic acid by COX-1 produces thromboxane A2 . ∘ Thromboxane A2 activates other platelets to aggregate. Antiplatelet drugs • Inhibit thrombus formation in the arterial circulation. • In faster flowing vessels, thrombi predominantly contain platelets with little fibrin. General Principles 77 Non-steroidal anti-inflammatory drugs (NSAIDs) • Produce reversible inhibition of both COX isoforms. • Duration of antiplatelet action depends on the specific drug’s pharmacokinetics. ∘ Ranges from 8 hours to 3 days. • Selective COX-2 inhibitors, e.g. celecoxib, have no antiplatelet activity. Aspirin • A salicylate and NSAID. • It differs from other NSAIDs by causing irreversible inhibition of COX-1. • This inhibits generation of thromboxanes, required for platelet binding. • Reversal occurs over 7–10 days as the body replaces the suppressed platelets. Clopidogrel (Plavix® ) • A thienopyridine; irreversibly inhibits P2Y12 ADP receptors on platelets. ∘ This receptor is essential for activation of the glycoprotein IIb/IIIa pathway. • Does not inhibit COX; can be used in patients intolerant of aspirin. • Used in combination with aspirin following coronary stenting. • Effects persist until a new platelet population is manufactured (7–10 days). Dipyridamole • A phosphodiesterase (PDE) inhibitor. • This elevates platelet levels of cAMP by inhibiting its breakdown. • High cAMP levels reduce intracellular calcium. • Low calcium inhibits events leading to platelet degranulation. • By the same mechanism, it causes vasodilatation. • Usually given in combination with aspirin due to its modest antiplatelet activity. Glycoprotein IIb/IIIa antagonists • Examples: abciximab, eptifibatide, tirofiban. • Monoclonal antibodies (or their peptide derivatives) raised against the glycoprotein IIb/IIIa receptor. • Given parenterally by cardiologists to treat acute coronary syndromes. • Contraindicated within 4–6 weeks of trauma or major surgery. Further reading Flaps Behan FC. The Keystone Design Perforator Island Flap in reconstructive surgery. Plast Reconstr Surg 2003;73(3):112–20. Borges AF. Relaxed skin tension lines (RSTL) versus other skin lines. ANZ J Surg 1984;73(1):144–50. Cormack GC, Lamberty BGH. A classification of fascio-cutaneous flaps according to their pattern of vascularity. Br J Plast Surg 1984;37(1):80–7. Holm C, Mayr M, Höfter E et al. Perfusion zones of the DIEP flap revisited: a clinical study. Plast Reconstr Surg 2006;117(1):37–43. 78 Chapter 1 Hudson DA. Some thoughts on choosing a Z-plasty: the Z made simple. Plast Reconstr Surg 2000;106(3): 665–71. Jackson IT. Local Flaps in Head and Neck Reconstruction, 2nd edition. St. Louis: Quality Medical Publishing, 2007. Lin YT, Henry SL, Lin CH et al. The shunt-restricted arterialized venous flap for hand/digit reconstruction: enhanced perfusion, decreased congestion, and improved reliability. J Trauma 2010;69(2):399–404. Lister GD, Gibson T. Closure of rhomboid skin defects: the flaps of Limberg and Dufourmentel. Br J Plast Surg 1972;25(3):300–14. Mathes SJ, Nahai F. Classification of the vascular anatomy of muscles: experimental and clinical correlation. Plast Reconstr Surg 1981;67(2):177–87. Taylor GI, Palmer JH. The vascular territories (angiosomes) of the body: experimental study and clinical applications. Br J Plast Surg 1987;40(2):113–41. Wound healing Gauglitz GG, Korting HC, Pavicic T et al. Hypertrophic scarring and keloids: pathomechanisms and current and emerging treatment strategies. Mol Med 2011;17(1-2):113–25. Rinker B. The evils of nicotine: an evidence-based guide to smoking and plastic surgery. Ann Plast Surg 2013;70(5):599–605. Nerve Riedl O, Frey M. Anatomy of the sural nerve: cadaver study and literature review. Plast Reconstr Surg 2013; 131(4):802–10. Tendon James R, Kesturu G, Balian G et al. Tendon: biology, biomechanics, repair, growth factors, and evolving treatment options. J Hand Surg Am 2008;33(1):102–12. Transplantation Pidwell DJ, Burns C. The immunology of composite tissue transplantation. Clin Plast Surg 2007;34(2):303–17. Tobin GR, Breidenbach WC 3rd,, Pidwell DJ et al. Transplantation of the hand, face, and composite structures: evolution and current status. Clin Plast Surg 2007;34(2):271–8. Alloplastic implantation Eppley BL, Dadvand B. Injectable soft-tissue fillers: clinical overview. Plast Reconstr Surg 2006;118(4): 98e–106e. Dressings Glass GE, Nanchahal J. The methodology of negative pressure wound therapy: separating fact from fiction. J Plast Reconstr Aesthet Surg 2012;65(8):989–1001. General Principles 79 Tissue expansion Chummun S, Addison P, Stewart KJ. The osmotic tissue expander: a 5-year experience. J Plast Reconstr Aesthet Surg 2010;63(12):2128–32. Pasyk KA, Argenta LC, Austad ED. Histopathology of human expanded tissue. Clin Plast Surg 1987;14(3): 435–45. Microsurgery Anton H Schwabegger. Flap re-exploration. In: Wei F-C, Mardini S. Flaps and Reconstructive Surgery. Philadelphia: Saunders Elsevier, 2009:125–136. Kazuteru Doi. Nerves. In: Wei F-C, Mardini S. Flaps and Reconstructive Surgery. Philadelphia: Saunders Elsevier, 2009:71–79. Raja Sabapathy. Vessels. In: Wei F-C, Mardini S. Flaps and Reconstructive Surgery. Philadelphia: Saunders Elsevier, 2009:80–92. Whitaker IS, Izadi D, Oliver DW et al. Hirudo Medicinalis and the plastic surgeon. Br J Plast Surg 2004;57(4): 348–53. CHAPTER 2 Skin and Soft Tissue Lesions CHAPTER CONTENTS Benign nonpigmented skin lesions, 80 Benign pigmented skin lesions, 86 Malignant nonpigmented skin lesions, 91 Malignant melanoma, 101 Vascular anomalies, 113 Soft tissue tumours, 124 Bone sarcomas, 130 Further reading, 131 Benign nonpigmented skin lesions Skin lesions can derive from any of the constituents of skin: • Epidermis: ∘ Keratinocytes ∘ Melanocytes ∘ Merkel cells • Dermis: ∘ Hair follicles ∘ Sebaceous glands ∘ Apocrine glands ∘ Eccrine sweat glands ∘ Neural tissue • Miscellaneous: ∘ Epidermoid cysts ∘ Pilar cysts ∘ Milia ∘ Xanthelasma. Skin lesions of epidermal origin Seborrhoeic keratosis • Common; also known as basal cell papilloma. • Greasy plaque-like lesion usually found on the torso of elderly patients. • Treated by curettage. Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 80 Skin and Soft Tissue Lesions 81 Squamous papilloma • Common; also known as a ‘skin tag’ or ‘acrochordon’. • Treated by excision. Viral wart • Caused by epidermal infection with human papilloma virus (HPV). • Treated by cryotherapy, curettage or laser. Actinic (solar) keratosis (AK) • Scaly, crusted area; typically occurs on sun-exposed areas in the elderly. • Recent evidence suggests AK is part of a spectrum from sun-damaged skin to squamous cell carcinoma (SCC) in situ. ∘ 0.1% per year progress to SCCs ∘ 15–25% per year spontaneously regress. • Treatment, if indicated, is by cryotherapy, photodynamic therapy (PDT), or topical preparations of imiquimod, diclofenac or 5-fluorouracil (5-FU). Keratin horn • Hard, protruding lump of cornified material – proliferation of keratin. • The base is benign in 50%, malignant in 20% (usually SCC) and AK in 30%. • To rule out malignancy, biopsy should include the base of the horn. Bowen’s disease • First described by the American dermatologist John T Bowen (1912). • Red scaly lesion usually found on the legs of elderly patients. • Histologically resembles SCC, but abnormalities are limited to epidermis. ∘ Therefore, best regarded as in situ SCC. • 3–5% develop into invasive SCCs. • Treatment options: cryotherapy, curettage, excision, topical 5-FU, imiquimod, PDT. Keratoacanthoma (KA) • Benign epithelial tumour of pilosebaceous origin composed of keratinising squamous cells. • Characterised by rapid evolution (weeks or months) into a nodule with a central keratotic core. • Followed by spontaneous involution to leave a depressed scar, usually within 4–6 months. • Histologically difficult to differentiate from SCCs. • Some maintain they are well-differentiated SCCs rather than a distinct entity. • Familial forms of KA include: ∘ Ferguson–Smith syndrome ∘ Muir–Torre syndrome. Ferguson–Smith syndrome • Linked to a single gene mutation on chromosome 9, characterised by: ∘ Autosomal dominant inheritance ∘ Multiple self-healing epitheliomas, which look and behave like KAs. 82 Chapter 2 • Most patients can trace their ancestry to a family living in Western Scotland in the 18th century. Muir–Torre syndrome • Described by Muir (1967), then Torre (1968). • Autosomal dominant inheritance in 2∕3 of cases, often with a germline mutation in one of the DNA mismatch repair genes hMLH1 or hMSH2. • Characterised by: ∘ One or more sebaceous neoplasms (sebaceous adenoma, sebaceous epithelioma, sebaceous carcinoma) or KAs ∘ One or more visceral malignancies (usually gastrointestinal or genitourinary carcinomas). Skin lesions of dermal origin • Over 80 different adnexal tumours described. • Most are benign, with a rarer malignant counterpart. • Classified histologically according to their predominant morphological component. Lesions with hair follicle (pilar) differentiation Trichoepithelioma • Translucent pinky-white nodules. • Often located around nose and mouth; may run in families. • Can be difficult to distinguish from basal cell carcinomas (BCCs). Trichofolliculoma • Nodules with a central pore that often contains white hairs. • Histologically resemble BCCs. • However, unlike BCCs, they contain keratin-filled macrocysts. Trichoblastoma • Typically a slow-growing solitary nodule in the head and neck. • Commonly mistaken (clinically and histologically) for trichoepithelioma and BCC. Trichilemmoma • Small, skin-coloured, warty papules usually found on the face. • Multiple trichilemmomas are diagnostic of Cowden’s disease. Cowden’s disease • Autosomal dominant; thought to be due to germline mutations in the tumour suppressor gene PTEN. • Characterised by multiple hamartomas and high risk of breast, endometrial and thyroid carcinoma. Skin and Soft Tissue Lesions 83 • Mucocutaneous lesions affect over 90% of patients: ∘ Facial trichilemmomas ∘ Acral keratoses ∘ Oral papillomatous papules and mucosal cobblestoning. • Hamartomatous polyps of the intestinal tract found in 40–60% of patients. Pilomatrixoma • Also known as calcifying epithelioma of Malherbe. • Arises from outer root sheath cells of hair follicles. • Typically, a solitary rock-hard subcutaneous nodule on the face of children. ∘ 40% develop in the first decade of life; another 20% develop in the second decade. ∘ Most common in head and neck; may occur on arms, trunk and legs. ∘ Periocular tissues involved in 10–17%; 5% of cases are multifocal. • 75% have mutations in the CTNNB1 gene that codes for β-catenin. • Malignant change is rare. • Treated by excision. Lesions with sebaceous gland differentiation Sebaceous naevus • Also known as sebaceous naevus of Jadassohn, or organoid naevus. • Typically present at birth; may enlarge and become raised in puberty due to sebaceous gland hyperplasia. • Scalp lesions often excised on aesthetic grounds because they cause a bald patch. • Some excise these because of a 15% chance of transformation into a secondary tumour: ∘ Usually syringocystadenoma papilliferum (SCAP), trichoblastoma or trichilemmoma. ∘ Less common – malignant transformation into BCC, SCC, malignant appendigeal tumour. • Many advocate clinical follow-up rather than excision: ∘ Most secondary tumours arise in adulthood; most are benign. Sebaceous gland hyperplasia • Small yellowish papules; usually found on the face. • Dermoscopy helps differentiate between this and BCC. • Rhinophyma is severe sebaceous hyperplasia of the nose. Sebaceous adenomas • Small smooth papules; usually occur on the scalp of the elderly. Lesions with sweat gland differentiation Poroma • Relatively common; present as small nodules on palms or soles of adults. 84 Chapter 2 Cylindroma • Pink lesions; usually occur on scalps of the elderly. • Large or multiple lesions known as ‘turban tumours’. Syringoma • Small, skin-coloured dermal papules. • Typically occur on the eyelid and chest of women. • A subtype of syringoma is associated with Down’s syndrome. Syringocystadenoma papilliferum (SCAP) • Solitary papule or smooth hairless plaque on scalp and forehead. • May occur de novo or in association with sebaceous naevus. Hidrocystoma • Cystic lesion; typically occurs on the face. • Can differentiate into apocrine and eccrine subtypes. Lesions derived from neural tissue Neurofibroma • Skin-coloured nodule composed of neural tissue and keratin. • Arises from nonmyelinating Schwann cells; often incorporates other cell types. • Classified into dermal and plexiform subtypes: ∘ Dermal (cutaneous) neurofibromas are associated with a single peripheral nerve. ∘ Plexiform neurofibromas are associated with multiple nerve bundles. • Plexiform neurofibromas are large infiltrative lesions usually found in the head and neck. • Two types of plexiform neurofibroma: 1 Nodular 2 Diffuse. • Diffuse form also known as elephantiasis neurofibromatosa. ∘ Characterised by wrinkled, pendulous appearance due to overgrowth of skin and subcutaneous tissue. • Wound complications are common following excision. • Neurofibromas can occur as solitary lesions or associated with neurofibromatosis (NF). • This is discussed further in Chapter 3, ‘Craniofacial surgery > Neoplasia–hyperplasia’. Neurilemmoma • Also known as schwannoma; composed solely of myelinating Schwann cells. ∘ Therefore, more homogeneous than neurofibroma. • Encapsulated tumours; can be separated from the parent nerve, unlike neurofibroma. • Multiple neurilemmomas should raise the possibility of NF. Miscellaneous Inclusion cysts • Implantation cysts result from trapping a segment of epidermis within dermis following trauma. Skin and Soft Tissue Lesions 85 Dermoid cysts • Occur following entrapment of embryonic epithelium at sites of fusion during facial development. • Usually submuscular; found towards the outer corner of the eye (angular dermoids) or in the midline between forehead and nasal tip (central dermoids). • Also found more posteriorly, associated with the anterior fontanelle. • Central dermoids may have deep intracranial extensions. ∘ Preoperative radiological assessment is recommended. Epidermoid cysts • Most common superficial cysts; often incorrectly referred to as sebaceous cysts. • Firm subcutaneous swellings attached to skin. • May have an overlying punctum; frequently located in the cheek. • Histologically, consist of stratified squamous epithelium surrounding keratinised material, as well as sebum secreted by sebaceous glands. • Treated by excision of the cyst with the overlying punctum. • Incomplete excision can result in recurrence. Gardner syndrome • Autosomal dominant, characterised by a triad of: 1 Familial polyposis coli with 100% risk of malignant transformation 2 Multiple skin and soft tissue tumours – Epidermoid cysts, desmoid tumours, other benign tumours. 3 Jaw osteomas. Pilar cysts • Also known as trichilemmal cysts. • Similar to epidermoid cysts but derive from the outer root sheath of hair follicles. • Typically occur on the scalp. • Most occur sporadically; some are autosomal dominant. • Treated by surgical excision. Milia • Small, keratin-filled intraepidermal cysts. • Usually occur on the cheeks. • In children, they typically disappear on their own. • In adults, they may require treatment by needle enucleation. Xanthelasma • Represent accumulation of lipid within the skin. • Usually located around the eyes as thin, well-demarcated plaques. • Xanthelasmata that become large or nodular are called xanthomas. • Myocardial infarction, ischaemic cardiovascular disease and death are commoner in patients with xanthelasmata than in those without. ∘ Serum lipids should be checked: 50% will have hypercholesterolaemia. • Removal is accomplished by excision, laser or topical trichloroacetic acid peel. 86 Chapter 2 Benign pigmented skin lesions Structure and function of melanocytes Melanocytes • Derived from the neural crest. • Spindle-shaped clear cells with dendritic processes and dark nucleus. • The number of melanocytes does not vary between races. Melanin • Synthesised within melanocytes from the amino acid tyrosine, via the intermediate Dopa. • Accumulates in vesicles within melanocytes called melanosomes. • Melanosomes are distributed to surrounding cells via long dendritic processes. ∘ Reminiscent of synaptic transmission, reflecting neural crest origins. • Once inside the keratinocyte, melanin is orientated over the external-facing surface of the nucleus like a sun shade. • Cells around melanocytes usually contain more melanin than the melanocytes themselves. • Increased pigmentation of dark-skinned people is due to increased basal production of melanin. • Melanin production is stimulated by UVB light and melanocyte-stimulating hormone (MSH). Naevus cells • When melanocytes leave the epidermis and enter the dermis they become naevus cells. • Naevus cells differ from melanocytes: ∘ Round rather than spindle shaped ∘ No dendritic processes ∘ Tend to congregate in nests. Melanocytic lesions • In loose terms, a ‘naevus’ is any congenital skin lesion, ‘mole’ or ‘birthmark’. • In pathological terms it is a well-circumscribed hamartoma of skin or oral mucosa, not due to external causes. • A naevus (singular) or naevi (plural) may involve epidermal, connective, adnexal, neural or vascular tissues. • Naevi are benign by definition, but malignancies can arise from them. • Most use the term ‘naevus’ to describe pigmented naevi. • Benign melanocytic lesions either contain naevus cells or melanocytes: ∘ Naevus cell naevi can be congenital or acquired. ∘ Melanocytic naevi originate in either epidermis or dermis. • Melanocytic lesions can be benign or malignant. ∘ Malignant melanocytic lesions are melanomas; also known as malignant melanomas. Skin and Soft Tissue Lesions Classification Naevus cell naevi • Congenital ∘ Giant congenital melanocytic naevus (CMN) ∘ Non-giant CMN • Acquired ∘ Junctional naevus ∘ Compound naevus ∘ Intradermal naevus • Special naevi ∘ Spitz naevus ∘ Atypical naevus ∘ Halo naevus. Melanocytic naevi • Epidermal ∘ Ephelis ∘ Lentigo ∘ Café-au-lait patch ∘ Becker naevus ∘ McCune–Albright syndrome • Dermal ∘ Blue naevus ∘ Mongolian blue spot ∘ Naevus of Ota ∘ Naevus of Ito. Congenital naevus cell naevi Congenital melanocytic naevi • • • • • • Brown or black lesions present at birth. Classified as ‘giant’ if projected to be >20 cm diameter in adulthood. Giant CMN are sometimes called giant hairy naevi. Annual incidence for all sizes of CMN is approximately 2%. Giant CMN is much rarer – annual incidence 1 in 20,000. Significant risk of central nervous system (CNS) abnormalities with CMN of any size: ∘ Disorders of CNS development ∘ Intracranial melanosis ∘ Nonmelanotic intracranial abnormalities. Rationale for treatment • Two factors historically influenced CMN treatment: 1 Risk of malignant transformation 2 Aesthetic appearance. 87 88 Chapter 2 Risk of malignant transformation • Lifetime risk of malignant change within CMN is controversial: ∘ Previous studies reported risk of melanoma up to 45%. ∘ More recent prospective reports show risk of melanoma is 0.7–2.4%. • Median age at diagnosis of melanoma is 7 years. • Risk of malignancy seems to be associated with increasing CMN size. • A significant proportion of melanomas in CMN patients arise outside the CMN, and even outside the skin. • Both benign and malignant leptomeningeal melanosis, associated with CMN, carry poor prognosis. • Risk factors for associated neurocutaneous melanosis: ∘ Multiple satellite naevi. ∘ Signs of abnormal neurodevelopment, including seizures. ∘ CMN in the midline of the trunk and calvarium. ∘ Projected adult size >40 cm. • Patients with risk factors should be screened by CNS magnetic resonance imaging (MRI) before 6 months of age. Aesthetic appearance • Many CMNs lighten spontaneously over the course of years. ∘ A few become darker, hairy and nodular, causing aesthetic and oncological concerns. • This should be explained to patients considering treatment. Treatment • The best treatment of CMN is controversial. • Surgery to reduce malignancy risk is fallacious. • Nevertheless, some believe naevus cells are located superficially in the neonatal period and become deeper thereafter – termed ‘Abtropfung’ by Unna (1893). • Applying this belief, naevus cells can easily be removed by curettage and dermabrasion if done in the first few days or weeks of life. ∘ However, this opinion is based on an outdated view of melanocyte migration. • Neonatal surgery is hazardous with a narrow window of permissible blood loss. • Following this kind of superficial surgery, there may be difficulty in monitoring changes in the residual naevus cells, which lie deeper in the dermis. • The current practice of the multidisciplinary team (MDT) at Great Ormond Street Hospital, London is summarised as: ∘ No surgery offered for risk reduction. ∘ Routine surgery postponed until after the first year, when risks of anaesthesia are lower. ∘ Serial annual photography to assess spontaneous lightening. ∘ Surgery for cosmetic reasons may be offered to: – Those with facial CMN – Those with a single, easily excisable CMN. Skin and Soft Tissue Lesions 89 Acquired naevus cell naevi • Rare in infancy. • Incidence increases steadily during childhood, sharply during adolescence, more slowly in early adulthood and plateaus in middle age. • There are three main types of acquired naevus cell naevi. Junctional naevi • Flat, smooth, irregularly pigmented lesions. • Usually found in the young. • Nests of naevus cells clustered at the dermoepidermal junction. Compound naevi • Round, well-circumscribed, slightly raised lesions. • Nests of naevus cells clustered at the dermoepidermal junction extending into dermis. Intradermal naevi • Dome-shaped lesions; may be nonpigmented or hairy. • Tend to occur more in adults. • Nests of naevus cells clustered solely within dermis. Special naevus cell naevi Spitz naevi • Benign lesions; also known as epithelioid cell naevi. • The misleading term ‘juvenile melanoma’ should no longer be used because: ∘ They can occur in adults. ∘ They are not melanomas. • Usually present in early childhood as firm reddish-brown nodules. • Histologically, they share features common to all melanocytic naevi. • Treated by excision with narrow margins. • Histological examination distinguishes Spitz naevus from: ∘ Atypical Spitz naevus (spitzoid tumour of uncertain biological potential) – Borderline lesion – does not satisfy criteria for either Spitz naevus or frank melanoma. ∘ Malignant Spitz naevus (spitzoid melanoma) – This is frankly malignant. Atypical naevi • Can occur sporadically or run in families. • Diagnosed based on defined criteria, as discussed in ‘Malignant melanoma > Premalignant lesions’. Halo naevi • An otherwise normal melanocytic naevus with a peripheral area of depigmentation. 90 Chapter 2 • Depigmentation represents regression due to immunological factors. ∘ Anti-melanoma antibodies detected in some patients. • Relatively common in older children and teenagers. • Tend to regress leaving a small scar. • Treatment is expectant. Epidermal melanocytic naevi Ephelis • • • • Commonly known as a freckle. Contains a normal number of melanocytes. Pigmentation is due to increased melanin production. Lesions are said to disappear in the absence of sunlight. Lentigo • Contains an increased number of melanocytes. • Persists in the absence of sunlight. • Different types of lentigo have been described, including: ∘ Lentigo simplex – occurs in the young and middle aged ∘ Lentigo senilis – occurs in the elderly ∘ Solar lentigo – occurs after sun exposure. Café-au-lait patch • Pale brown macule. • Histologically there are ‘macromelanosomes’ in basal melanocytes. • Six or more >5 mm in children (>15 mm in adults) required to support a diagnosis of NF1. Becker naevus • Described by the American dermatologist Samuel William Becker (1948). • Dark patch on the chest, shoulder or back. • Normally appears during adolescence; may become hairy. • Predominantly affects males. McCune–Albright syndrome • Characterised by the triad of: 1 Café au lait macules 2 Polyostotic fibrous dysplasia 3 Endocrine dysfunction with precocious puberty. Dermal melanocytic naevi • Characterised by presence of melanocytes within the dermis. Blue naevus • Appears as a round area of blue-black discolouration. Skin and Soft Tissue Lesions 91 • Two variants: 1 Common blue naevus, usually <1 cm in diameter 2 Cellular blue naevus, usually >1 cm in diameter. • Thought to result from arrested migration of melanocytes bound for the dermoepidermal junction. Mongolian blue spot • Characterised by blue-grey pigmentation over the sacrum. • Said to be present in 90% of Mongolian infants. • Can be mistaken for bruising and attributed to nonaccidental injury of children. Naevus of Ota • Described by Ota and Tanino (1939). • Bluish pigmentation on the face in the distribution of the ophthalmic and maxillary divisions of the trigeminal nerve. • May also involve ocular and oral mucosal surfaces. • Causes glaucoma in up to 10% of patients. • Uncommon in Caucasians; prevalent among Japanese. Naevus of Ito • Described by Minor Ito (1954). • Blue-grey discolouration in the shoulder region. • Rare in Caucasians; common among Japanese. Malignant nonpigmented skin lesions • Nonpigmented skin cancer is the most common malignancy in the Western world: ∘ BCC ∘ SCC ∘ Merkel cell carcinoma (MCC) ∘ Sebaceous carcinoma. Aetiology Premalignant conditions • • • • • Bowen’s disease AKs Sebaceous naevi Leukoplakia Erythroplakia. Radiation • UVA and UVB both associated with development of skin malignancy. • Ionising radiation, often iatrogenic. 92 Chapter 2 Immunosuppression • Hampers cell-mediated immunity. • Reduces the number and activity of natural killer (NK) cells. Chronic wounds • Marjolin’s ulcer is SCC arising within an area of chronic inflammation. ∘ Classically presents as unhealed areas within venous ulcers, old burns, chronic sinuses. Toxins • Soot – historically, high incidence of scrotal cancer in chimney sweeps. • Arsenic – an ingredient of Bell’s Asthma Medicine and Fowler’s solution. Genetic Xeroderma pigmentosum • Deficiency of thiamine dimerase. • Thiamine absorbs UV light and forms dimers. ∘ These dimers cannot be broken down due to the enzyme deficiency. • Buildup of thiamine dimers induces defects in DNA and carcinogenesis. Albinism • Characterised by absence of melanin. • Skin is particularly sensitive to UV light. Fair skin • Fitzpatrick classified skin type based on colour and response to UV light: ∘ Type I: pale white skin, always burns, never tans. ∘ Type II: white skin, always burns easily, tans minimally. ∘ Type III: light brown skin, burns moderately, tans uniformly. ∘ Type IV: moderate brown skin (Mediterranean complexion), burns minimally, always tans well. ∘ Type V: dark brown skin (Indian complexion), rarely burns, tans profusely. ∘ Type VI: deep brown to black skin, never burns. • Fitzpatrick type I and II skin have a higher incidence of skin cancer. Basal cell carcinoma (BCC) • A slow-growing, locally invasive malignant epidermal skin tumour. • Usually emerges from keratinocyte stem cells in hair follicles, sebaceous glands or interfollicular basal cells. • BCC was known as mariner’s disease in the 19th century. • In France, it was known as ‘cancer des cultivateurs’. Epidemiology • Most common neoplasm in Caucasians in the Western world. • 85% occur after 40 years of age. • 80% occur in sun-exposed sites of the face, head and neck, arms and dorsal hands. • Over 300 cases of metastatic BCC are reported. Skin and Soft Tissue Lesions Pathogenesis • Most cases are sporadic. ∘ Associated with sun exposure, particularly UVB. • UV radiation induces gene mutations, notably in p53 and PTCH1. ∘ The hedgehog pathway is affected by mutations in these tumour suppressor genes. ∘ Gorlin’s syndrome and xeroderma pigmentosum have mutations in these genes. • UV-induced inflammation of the skin is also thought to contribute to pathogenesis. Histological appearance • Composed of sheets or nests of small round basophilic cells. • Peripheral palisading of nuclei at the margins of cell nests. • Inflammatory infiltrate and ulceration may also be seen. Classification • 26 histopathological types described by Wade and Ackerman (1978). • The three types common to all published studies, accounting for 90% of all types: ∘ Nodular (30–75%) ∘ Superficial (10–15%) ∘ Infiltrative (10%). Prognostic factors • BCCs are stratified into high or low risk of recurrence following treatment. • Increased risk of local recurrence is caused by: ∘ Patient factors ∘ Macroscopic features ∘ Microscopic features. Patient factors • Immunosuppression. Macroscopic features • Increasing tumour size. • Location: central face, especially around eyes, nose, lips and ears. • Poorly defined lesions. Microscopic features • Histological subtypes – infiltrative and morphoeic are high risk. • Perineural or perivascular involvement. • Recurrent lesions. Basal cell naevus syndrome • Also known as Gorlin’s syndrome, or Gorlin–Goltz syndrome. • Autosomal dominant; associated with germline mutations in PTCH gene. • Characterised by some or all of the following: ∘ Multiple BCCs that appear at an early age ∘ Palmar and plantar pits 93 94 Chapter 2 ∘ ∘ ∘ ∘ ∘ Odontogenic keratocysts, more common in mandible than maxilla Bifid ribs Calcification of the falx cerebri Overdevelopment of supraorbital ridges with mild hypertelorism Learning difficulties affect 5% of cases. • Associated with congenital blindness, hypogonadism and 75% of females develop ovarian fibromas. • Also increased incidence of CNS tumours, including medulloblastoma. ∘ Medulloblastoma occurs in childhood and may therefore be the presenting feature of Gorlin’s. Treatment of BCC • Nonsurgical • Surgical, which may be: ∘ Destructive – curettage and cautery, cryotherapy, laser ∘ Nondestructive – excision. • Most plastic surgeons are concerned with excisional techniques. Surgical treatment • Most are treated by excision with predetermined margins. • Deep margin should be into subcutaneous fat as a minimum. • Peripheral margins for well-defined lesions <2 cm: ∘ 3 mm clears the tumour in 85% of cases. ∘ 4–5 mm clears the tumour in 95% of cases. • Large or poorly defined lesions, e.g. morphoeic BCC, require wider excision: ∘ 3 mm clears the tumour in 66% of cases. ∘ 5 mm clears the tumour in 82% of cases. ∘ 13–15 mm clears the tumour in >95% of cases. • Up to 2% of BCCs reported as having clear margins will recur. ∘ May be due to sampling error during vertical sectioning – so-called ‘bread-loafing’. – With this technique, only about 40% of the specimen margin is assessed. Mohs micrographic surgery • An alternative to excision with predetermined margins. • Developed by Dr Frederic Mohs (1938) while a medical student at University of Wisconsin–Madison. • Gives high cure rates with maximal preservation of normal tissue. • Labour intensive; reserved for high-risk lesions in cosmetic areas on the face. • Assesses the entire specimen margin intraoperatively: 1 Obvious tumour mass is removed with no regard for clear margins, leaving a saucer-shaped defect. 2 Peripheral margins of the defect are marked at 3, 6, 9 and 12 o’clock and the entire margin – both deep and peripheral – is excised with a ≈2 mm margin. Skin and Soft Tissue Lesions 95 3 This specimen, which looks like a shallow bowl, is squashed flat and rapidly frozen to allow sectioning parallel to the surface of the skin. 4 This yields sections containing skin of the periphery and fat of the base of the wound, allowing simultaneous assessment of the entire surgical margin. 5 Residual tumour is mapped to the orientation markings; further excision is targeted to those zones. 6 The process is repeated with further excision specimens until clear margins are obtained. Incompletely excised BCCs • Approximately 4–7% of BCCs are incompletely excised. • Rate of incomplete excision is higher at inner canthus, alar base and external auditory meatus. • Reasons for this are unclear: ∘ Invasion can proceed down natural embryonic fusion lines at these sites? ∘ BCCs overlying embryonic fusion lines are more likely to be infiltrative? ∘ Excision and reconstruction in these areas is more complex? • Treatment of incompletely excised BCC is controversial: ∘ Excision with intraoperative frozen section analysis of surgical margins. ∘ Delayed wound reconstruction until formal pathology report available. – Nicknamed ‘slow-Mohs’, although margins are assessed by conventional breadloafing, not Mohs. ∘ Observation of laterally incomplete lesions – only 17% recur. – However, incomplete excision of the deep margin has 33% risk of recurrence. • Re-excision shows residual tumour in only 55% of cases using Mohs; even less frequently with bread-loafing. • Risk of recurrence is highest: ∘ Where both lateral and deep margins are involved ∘ For excisions of recurrent BCCs ∘ For radio-recurrent lesions. • Re-excision is particularly recommended in the following situations: ∘ Involvement of critical midfacial sites ∘ Involvement of deep surgical margin ∘ Aggressive histological subtypes ∘ Where flaps or skin grafts have been used, which might mask recurrence. • UK guidelines recommend excision with wider predetermined margins of 5–10 mm, or Mohs. • Radiotherapy is effective in preventing recurrence following incomplete excision. Other treatment options • Destructive methods are best applied to low-risk lesions. ∘ Adequacy of excision cannot be assessed by histopathology. • Confirming the low-risk nature of a BCC may require biopsy prior to treatment. 96 Chapter 2 Curettage and cautery • Common amongst dermatologists. • Best suited for small, well-demarcated tumours. • Wound left to heal by secondary intention; usually cosmetically acceptable. Cryotherapy • Repeated freeze–thaw cycles cause ice crystals to form in and around tumour cells; causes ischaemia by vascular stasis. • Risk of hyper- or hypopigmentation of darker skin tones. Radiotherapy • Cure rates similar to excision; excellent early cosmetic results. • Atrophic changes occur over time – unsuitable for treatment of young patients. • Following treatment a scab forms that takes several weeks to separate. • Useful for elderly patients unsuitable for surgery. Photodynamic therapy (PDT) • A photosensitising chemical, e.g. MAL (methyl aminolevulinate – Metvix® ) makes the tumour more susceptible when treated with a light source. • Efficacy depends on how deeply MAL penetrates the tumour. • Bright light causes MAL to generate oxygen radicals that induce cell death. CO2 laser • Controversial treatment with mixed results; best reserved for superficial BCCs. • Combining CO2 laser with PDT is a new approach, with clearance rates comparable to surgery. Imiquimod (Aldara® ) • Topical immune response modifier; can be used for superficial BCCs. • Binds to Toll-like receptor-7 on macrophages and dendritic cells to induce production of interferon-α, tumour necrosis factor (TNF-α) and various interleukins. • This promotes a cell-mediated immune response against the tumour. • In addition, imiquimod decreases expression of Bcl-2, leading to tumour apoptosis. • Applied for 6 weeks; can cause local and systemic side effects. 5-Fluorouracil (Efudix® ) • Applied topically to low-risk superficial BCCs. • 5-FU is an analogue of thymine; inhibits thymidylate synthetase. • This disturbs DNA synthesis, leading to cell death. Vismodegib (Erivedge® ) • Systemic inhibitor of the hedgehog signalling pathway. • Used for metastatic BCC, or locally advanced disease not amenable to surgery/ radiotherapy. Skin and Soft Tissue Lesions 97 Cutaneous squamous cell carcinoma • Malignant tumour of the keratinising cells of the epidermis or its appendages. • Second most common skin cancer; 20% of all cutaneous malignancies. • Commoner in males – lifetime risk 9–14%; 4–9% in women (US data). Risk factors • Chronic exposure to ultraviolet light or other radiation – sunbeds, outdoor workers. • Premalignant lesions – keratin horns, AK, leukoplakia, Bowen’s disease. • Smoking – particularly for lip SCC. • Immunodeficiency – recipients of organ transplants. • Chronic wounds and inflammation – scars, burns, ulcers, psoriasis. • Toxins – arsenic. • Genetic predisposition – albinism, xeroderma pigmentosum. • Viral infection – HPV, herpes simplex. Histological appearance • Dysplastic epidermal keratinocytes invade through basement membrane into dermis. • The degree of keratinisation is variable – presence of keratin pearls is characteristic. Prognostic factors • SCCs are prone to local recurrence and metastases. • Local recurrence rates are 3–23%, depending on location of the primary. • Adverse prognostic factors include: ∘ Patient factors ∘ Macroscopic features ∘ Microscopic features ∘ Previous treatment and treatment modality. Patient factors • Immunosuppression. Macroscopic features Anatomical site • Sites most prone to metastatic spread: 1 Areas of radiation or thermal injury, chronic draining sinuses, chronic ulcers, chronic inflammation or Bowen’s disease – 38%. 2 Non-sun-exposed sites (e.g. perineum, sacrum, sole of foot) – 38%. 3 Lip – 14%. 4 Ear – 9%. 5 Sun-exposed sites, excluding lip and ear – 5% (this is the only category considered ‘low risk’). Tumour size • Tumours >2 cm diameter twice as likely to recur locally and three times as likely to metastasise as smaller tumours. 98 Chapter 2 Microscopic features Depth of invasion • Tumours >4 mm depth (excluding surface layers of keratin) or extending into subcutaneous fat are more likely to recur and metastasise than thinner tumours. • Tumours with perineural involvement, lymphatic or vascular invasion more likely to recur and metastasise. Histological differentiation/Broders grade • Broders grade is based on the ratio of differentiated to undifferentiated cells: ∘ Grade 1 – ratio of 3:1 ∘ Grade 2 – ratio of 1:1 ∘ Grade 3 – ratio of 1:3 ∘ Grade 4 – No tendency towards differentiation. • Poorly differentiated tumours (Broders 3 and 4) have poorer prognosis: ∘ >2× local recurrence rate and 3× metastatic rate compared to Broders 1 and 2. Histological subtype • Acantholytic, spindle and desmoplastic have poorer prognosis than verrucous subtype. Previous treatment and treatment modality • Primary treatment with Mohs surgery has the lowest rate of recurrence. • Locally recurrent disease is a risk factor for metastatic disease. TNM staging Primary tumour (T) • Tis: carcinoma in situ. • T1: tumour ≤2 cm with <2 high-risk features. • T2: tumour >2 cm or tumour any size with ≥2 high-risk features. • T3: tumour with invasion of maxilla, mandible, orbit or temporal bone. • T4: tumour with invasion of skeleton (axial or appendicular) or perineural invasion of skull base. High-risk features for T staging: • Depth/invasion ∘ >2 mm thickness ∘ Clark level ≥ IV ∘ Perineural invasion • Anatomic location ∘ Primary site ear ∘ Primary site non-hair-bearing lip • Differentiation ∘ Poorly differentiated or undifferentiated. Skin and Soft Tissue Lesions 99 Regional lymph nodes (N) • N0: No regional lymph node metastasis. • N1: Metastasis in a single ipsilateral lymph node ≤3 cm. • N2a: Metastasis in a single ipsilateral lymph node, >3 cm but not >6 cm. • N2b: Metastasis in multiple ipsilateral lymph nodes, none >6 cm. • N2c: Metastasis in bilateral or contralateral lymph nodes, none >6 cm. • N3: Metastasis in a lymph node >6 cm. Distant metastasis (M) • M0: No distant metastases • M1: Distant metastases. Treatment Surgery • Excision with histological examination of the margins is the treatment of choice for most cutaneous SCCs, achieving complete removal in 95% of cases. • Recommended peripheral margins for cutaneous SCCs are: ∘ Minimum 4 mm for clinically well-defined, low-risk tumours <2 cm. ∘ Minimum 6 mm margin for higher risk tumours, including: – >2 cm diameter – Moderate, poor or no differentiation – Extending into subcutaneous tissue – On the ear, lip, scalp, eyelids or nose. • Larger, indistinct tumours should be excised with larger margins or Mohs surgery. Referral to a skin cancer multidisciplinary team (MDT) • Patients with high-risk SCC and/or involved lymph nodes should be reviewed by a specialist MDT for multimodality treatment planning. Radiotherapy • Cure rates >90%. Other treatment options • Cryotherapy, and curettage and cautery used by dermatologists for low-risk lesions. Merkel cell carcinoma (MCC) • Rare, aggressive, primary cutaneous neuroendocrine carcinoma. • Merkel cells are mechanoreceptors of neural crest origin. Epidemiology • Estimated annual incidence 1 in 500,000. • Commoner in elderly Caucasians; males and females equally affected. 100 Chapter 2 Aetiology • 80% thought to be caused by Merkel cell polyomavirus (MCPyV). • Also linked to previous radiation exposure and B-cell lymphoma. Clinical features • Present as rapidly growing, firm, painless purple-red nodules. • Most prevalent in sun-exposed sites: ∘ 50% in the head and neck; 35% in the extremities. • Up to 15% have involved lymph nodes on presentation. • Up to 83% eventually develop nodal disease or distant metastases. Histology • Diagnosis on light microscopy alone is difficult because MCC appears similar to other undifferentiated small-cell neoplasms, e.g. small-cell lung carcinoma. • Three histological types: 1 Classic trabecular (10%) 2 Intermediate (80%) 3 Small-cell variant (10%). • Immunohistochemistry is usually required to confidently diagnose MCC. ∘ Cytokeratin 20 and neurofilament protein unequivocally identify Merkel cells. • A chest X-ray helps exclude a lung primary with secondary skin metastasis. Prognosis • MCCs are locally aggressive, with a higher rate of regional metastasis than melanoma. • 5-year survival for primary MCC is 75% for the primary tumour, 59% for local recurrence and/or lymph node metastases and 25% for distant metastases. • Factors adversely affecting prognosis: ∘ Increasing disease stage ∘ Male sex ∘ Lesions in the head and neck or trunk ∘ Immunosuppression ∘ Small-cell variant, which is relatively undifferentiated ∘ Increasing tumour thickness. Treatment • Mainstay is aggressive wide local excision of the primary tumour. • 2–3 cm margins recommended – believed to decrease risk of local recurrence. • 55% of patients develop regional lymph node metastases. ∘ Some advocate elective neck dissection. ∘ Adjuvant radiotherapy may be directed at the primary site and likely lymphatic basins. ∘ Chemotherapy regimes similar to those used for small-cell lung cancer can be used for palliation in advanced disease. • There are no evidence-based indications for neck dissection or adjuvant therapy. • Patients are usually managed by a specialist MDT. Skin and Soft Tissue Lesions 101 Sebaceous carcinoma • Rare and aggressive tumour arising from sebaceous glands. • Presents as a yellow or orange nodule. • Approximately 75% occur in the periocular region. ∘ In this region, they commonly affect the elderly, particularly females and Asians. ∘ Often resemble a chalazion, which can delay the diagnosis. ∘ Periorbital lesions are associated with poor prognosis. • Prone to both local and distant recurrence. ∘ Local recurrence as high as 36%, even with Mohs surgery. • May present as part of Muir–Torre syndrome. ∘ Patients should be referred to a gastrointestinal MDT for intra-abdominal malignancy screening. • Treated by wide local excision. Malignant melanoma • A melanoma – or malignant melanoma (MM) – is a malignant tumour of melanocytes. Epidemiology • Fifth most common cancer in the United Kingdom; 4% of all new cancers. • Almost 13,000 new cases per year in the United Kingdom. • Annual incidence approximately 20 per 100,000 population. ∘ This is four times higher than 30 years ago. • Lifetime risk of MM in the United Kingdom is 1 in 60. • Lifetime risk in Australia is 1 in 25 for males; 1 in 34 for females. • 27% of MM occurs <50 years; 45% occurs >65 years of age. • More women than men are affected in younger age groups: ∘ Male:female ratio is 4:10 in 20–24 year olds. ∘ This is reversed in the over 85 year olds to 16:10. • MM in males most frequently found on trunk (41%), head and neck (22%). • MM in females most frequently found on leg (39%), arm (24%). Risk factors • The mnemonic is ‘PPARENTS’: ∘ Premalignant lesions ∘ Previous melanoma ∘ Age ∘ Race ∘ Economic status – The affluent are likely to experience childhood sunburn due to holidays abroad. ∘ Naevi – >50 ordinary naevi, familial atypical mole and melanoma (FAMM) syndrome ∘ Fitzpatrick Type 1 and 2 skin ∘ Sunburn and sunbed use. – MM four times more frequent after severe sunburn <10 years of age. • Risk stratification helps identify those who should be referred to a specialist: 102 Chapter 2 Moderately increased risk of melanoma • Approximately 8–10 times that of the general population: ∘ Previous primary melanoma ∘ Large number of moles (some of which may be clinically atypical) ∘ Organ transplant recipients. Greatly increased risk of melanoma • >10 times that of the general population: ∘ Giant congenital melanocytic naevus ∘ Strong family history of melanoma or pancreatic carcinoma. Premalignant lesions Atypical naevi • 7% of the general population have at least one atypical naevus. • Defined as having at least three of these features: ∘ Size >5 mm ∘ Ill-defined borders ∘ Irregular margin and shape ∘ Variegated colour ∘ Both macular and papular components. • FAMM syndrome (previously called atypical naevus syndrome) is defined as: ∘ One or more first-degree or second-degree relatives with MM. ∘ Large number of naevi (often >50), some of which are atypical. ∘ Naevi that are dysplastic on histological examination. • Patients with FAMM have a lifetime risk of melanoma close to 100%. • Prophylactic removal of abnormal naevi does not improve survival because MM can arise de novo. Congenital melanocytic naevi • Risk of MM in patients with CMN is 0.7–2.4%. Pathogenesis • Unclear; known to involve progressive genetic mutations. • Mutations may increase susceptibility to carcinogenic effects of UV radiation. Gene mutation • 50% of MMs carry mutations in the gene encoding the BRAF enzyme. • BRAF is a component of the mitogen-activated protein kinase (MAPK) cell signalling pathway. • Activation of BRAF leads to phosphorylation of MEK and ERK kinases, which promote cell proliferation and survival. • Mutations in BRAF (most commonly V600E) result in constitutive activation of the MAPK pathway, causing uncontrolled cell proliferation. Ultraviolet radiation • Arbitrarily classified as follows: Skin and Soft Tissue Lesions 103 ∘ UVA (315–400 nm) – Emitted by most sunbeds. – Exposure is thought, but not proved, to increase risk of MM. ∘ UVB (280–315 nm) – Causes sunburn. – Known risk factor for MM. ∘ UVC (200–280 nm) – Mostly filtered out by the ozone layer. • UVB is strongly absorbed by DNA, resulting in chromosomal damage. • Increasing evidence that UVA also damages DNA by generation of oxygen radicals. Assessment • Prompt diagnosis is crucial for successful treatment of MM. ABCD rule • Developed by the Melanoma Clinical Cooperative Group at New York University School of Medicine: ∘ Asymmetry ∘ Border irregularity ∘ Colour is uneven ∘ Diameter >6 mm ∘ (Evolving). Glasgow seven-point checklist • MacKie described this aid for identification of MM. • The following increases the likelihood of a lesion being MM: ∘ Major signs 1 Change in size 2 Change in shape 3 Change in colour ∘ Minor signs 1 Inflammation 2 Crusting or bleeding 3 Sensory change 4 Diameter ≥7 mm. Dermoscopy and teledermoscopy • Dermoscopy images sent to a central hub for assessment provide an efficient way of triaging pigmented lesions. Differential diagnosis • Lesions confused with melanoma: ∘ Campbell De Morgan spot ∘ Junctional or compound naevi ∘ Kaposi sarcoma 104 ∘ ∘ ∘ Chapter 2 Pigmented BCC Pyogenic granuloma Seborrhoeic keratosis. Primary treatment • In the United Kingdom, lesions suspicious for MM should not be treated in primary care. • Referral is made to the Local Skin Cancer Multidisciplinary Team (LSMDT). Excision biopsy • 2 mm margins and a cuff of subcutaneous fat is recommended for lesions suspected of being MMs. • If direct closure is not possible, dressings are applied until results are available. • Definitive excision margins are determined once the histology result is available. Incision biopsy • Incision or punch biopsies are acceptable in these situations: ∘ Large lesions – diagnosis is confirmed before major reconstruction. ∘ Lentigos not amenable to excision and direct closure. ∘ Possible subungual melanomas. • Shave biopsy or curettage is not recommended. ∘ It makes measuring Breslow thickness impossible. TNM staging Primary tumour (T) • Tis: Melanoma in situ • T1: ≤1 mm in thickness ∘ a: without ulceration and mitosis <1/mm2 ∘ b: with ulceration or mitoses ≥1/mm2 • T2: 1.01–2.0 mm ∘ a: without ulceration ∘ b: with ulceration • T3: 2.01–4.0 mm ∘ a: without ulceration ∘ b: with ulceration • T4: >4.0 mm ∘ a: without ulceration ∘ b: with ulceration. Regional lymph nodes (N) • N0: No lymph node metastasis • N1: 1 node ∘ a: Micrometastasis ∘ b: Macrometastasis Skin and Soft Tissue Lesions 105 • N2: 2–3 nodes ∘ a: Micrometastasis ∘ b: Macrometastasis ∘ c: In-transit metastases/satellites without metastatic nodes • N3: Any of the following: ∘ ≥4 nodes ∘ Matted nodes ∘ In-transit metastases/satellites with metastatic nodes. Distant metastases (M) • M0: No distant metastases • M1: Distant metastasis: ∘ a: Skin, subcutaneous or nodal metastases ∘ b: Lung metastases ∘ c: All other visceral metastases; any distant metastasis with elevated serum lactate dehydrogenase (LDH). Definitions • Micrometastases ∘ Detected by immunohistochemical analysis of a sentinel lymph node biopsy (SLNB). • Macrometastases ∘ Clinically detectable lymph node metastases. • Microscopic satellites ∘ Nests of metastatic cells >0.05 mm in diameter, clearly separated by normal dermis (not fibrosis or inflammation) from the main MM by 0.3 mm. • In-transit metastases ∘ Grossly visible cutaneous or subcutaneous intralymphatic metastases >2 cm from the primary MM but before the regional lymphatic basin. • Satellite lesions ∘ Grossly visible cutaneous or subcutaneous intralymphatic metastases <2 cm from the primary MM. Clinical staging Stage T N M 0 IA IB IIA IIB IIC III IV Tis T1a T1b or T2a T2b or T3a T3b or T4a T4b Any T Any T N0 N0 N0 N0 N0 N0 N>0 Any N M0 M0 M0 M0 M0 M0 M0 M1 106 Chapter 2 Prognostic factors • In addition to TNM stage, adverse prognosis is associated with the following. Patient factors • Males worse than females. • Elderly worse than the young. Macroscopic features • Trunk, scalp, mucosal and perineal lesions have worse prognosis. Microscopic features Ulceration • Full-thickness loss of epidermis with reactive changes. Breslow thickness • Distance between stratum granulosum and deepest part of the MM. • Directly related to survival. Mitotic rate • Has replaced Clark’s level of invasion as the primary criterion for defining T1b MM. Histological subtype • Association between MM subtypes and prognosis is controversial. ∘ Apparent associations may be due to delays in diagnosis, leading to thicker or ulcerated MMs on presentation. • Superficial spreading melanoma ∘ Most common type; about 60% of cases. ∘ Usually a radial growth phase where the edges expand, followed by a vertical growth phase with palpable or visible nodular change. • Nodular melanoma ∘ Up to 30% of cases; usually more aggressive because it lacks a radial growth phase. ∘ About 5% of nodular MMs are amelanotic. • Lentigo maligna melanoma (LMM) ∘ MM arising in a lentigo maligna (LM); 7% of all MMs. – A lentigo is a macular lesion containing an increased number of normal melanocytes confined to epidermis. – LM is an increased number of abnormal melanocytes confined to epidermis, often called ‘melanoma in situ’. – LMM is an MM – it has invaded into the dermis. • Acral lentiginous melanoma ∘ 2% of all MMs, but up to 60% of MMs in deeply pigmented and Asian skin. ∘ Occurs on palms, soles and nail beds. • Amelanotic melanoma ∘ Rare MM; no identifiable pigment by light microscopy. ∘ Mimics other skin lesions; diagnosed late during the vertical growth phase. Skin and Soft Tissue Lesions 107 • Desmoplastic melanoma ∘ 1% of MMs. ∘ Propensity for perineural invasion; may increase local recurrence rates. Determining prognosis • A convenient resource can be found at www.melanomaprognosis.org. Minimum data set • The Royal College of Pathologists published a minimum data set that should be included in histology reports. • Site of tumour, type of surgical procedure, relevant clinical information. • Macroscopic description of the specimen and gross measurements. • Essential microscopy features: ∘ Ulceration, tumour thickness, mitotic count, histological subtype, margins of excision, pTNM stage. • Desirable microscopy features: ∘ Growth phase – radial or vertical, regression, tumour-infiltrating lymphocytes, lymphatic or vascular invasion, perineural infiltration, microsatellites, evidence of a precursor naevus. • Clark’s level of dermal invasion: ∘ Level I: tumour confined to epidermis. ∘ Level II: tumour extending into papillary dermis. ∘ Level III: tumour extending to the junction between papillary and reticular dermis. ∘ Level IV: tumour extending into reticular dermis. ∘ Level V: tumour extending into subcutaneous fat. • Clark’s level is no longer recommended for staging – it is not an independent prognostic factor when mitotic rate is included in the analysis. ∘ However, Clark levels IV or V can be used to define T1b when mitotic rate cannot be determined. Definitive treatment of the primary lesion • Once biopsy confirms diagnosis of MM and its Breslow thickness, the patient should undergo a wider and deeper excision of the biopsy scar with predetermined margins. ∘ Wider excision aims to improve locoregional control by removing any micrometastases. • The LSMDT decides margin size after discussion with the patient. Surgical excision margins • UK guidelines recommend peripheral excision margins based on Breslow thickness: ∘ LM and other in situ melanomas: 0.5 cm margin, sufficient for complete excision ∘ Breslow ≤1.0 mm: 1 cm margin ∘ Breslow 1.01–2.0 mm: 1–2 cm margin ∘ Breslow 2.01–4.0 mm: 2–3 cm margin ∘ Breslow >4 mm: 3 cm margin. • General consensus is to excise tissue down to, but not including, deep fascia. 108 Chapter 2 Staging investigations • Routine investigation not required in stage I, II or IIIA disease. • Stage IIIB or IIIC (palpable lymphadenopathy) – CT of head, chest, abdomen and pelvis prior to further surgery. • Stage IV (distant metastases) – serum LDH, CT scan (as for IIIB or IIIC) based on symptoms or clinical trial protocols. Management of lymph node basins Clinically node-negative patients Elective lymph node dissection • Little evidence of survival benefit after elective lymph node dissection (ELND). ∘ ELND does however cause significant morbidity. • The Melanoma Study Group recommends ELND not be performed outside of a trial. • Intergroup Melanoma Surgical Trial demonstrated some survival benefit of ELND in subsets of patients <60 years old with nonulcerated, intermediate-thickness melanomas (Balch et al., 1996). ∘ Did not demonstrate overall survival benefit for the whole cohort. ∘ The challenge is to identify those patients who might benefit from ELND. • SLNB was developed to try to meet this challenge. Sentinel lymph node biopsy • SLNB is considered for patients with disease at stage IB or higher. • Aims to identify the first draining node or nodes (the sentinel node) within a regional lymphatic basin. • The concept is based on two key assumptions: 1 Lymph drainage from a skin primary can be predicted by mapping the lymph pathway. 2 The primary malignancy will metastasise to a ‘sentinel’ node prior to other nodes. • Normally performed at the same time as wide local excision. • Preoperative lymphoscintigraphy, vital blue dye injection and gamma camera are used to identify the sentinel node or nodes. • Modern immunohistochemical techniques allow detection of only a few melanoma cells using antibodies against melanoma antigens, e.g. HMB-45 or Melan-A/MART 1. • Most with positive SLNB proceed to completion lymphadenectomy. • Benefits of SLNB: ∘ High sensitivity and specificity for subclinical regional lymph node involvement. ∘ Prognostic information: – Intermediate-thickness melanomas have 85% 10-year survival if SLNB negative, but 62% if SLNB positive. • Whether or not SLNB confers a survival benefit is controversial. • Disadvantages of SLNB include: ∘ 5% complication rate, including seroma, infection, nerve injury and lymphoedema. ∘ Failure to find a sentinel lymph node. ∘ False-negative result. Skin and Soft Tissue Lesions 109 Clinically or radiologically suspicious lymph nodes • Fine needle aspiration cytology (FNAC) of suspicious nodes helps confirm metastatic disease. • Negative FNAC in the face of strong clinical suspicion requires further FNAC, with radiological guidance if required. • Suspicious lymph nodes persistently negative on FNAC can be open biopsied. ∘ Biopsy incision is planned so it can be included in future completion lymphadenectomy. Treatment of patients with confirmed lymph node metastasis • Positive SLNB, FNAC or open biopsy is treated by radical lymphadenectomy. • It should be done by MDT members who perform high volumes of such surgery. Axillary dissection • Removes all nodes from Berg levels I to III. • May require division or resection of pectoralis minor. • Boundaries of the axilla: ∘ Apex: first rib, clavicle, scapula. ∘ Base: skin, fat and axillary fascia – colloquially known as ‘the armpit’. ∘ Anterior: pectoralis major and minor, clavipectoral fascia above and suspensory ligament of the axilla below pectoralis major. ∘ Posterior: subscapularis superiorly, teres major and latissimus dorsi inferiorly. ∘ Medial: first four ribs and intercostals, superior slips of serratus anterior. ∘ Lateral: anterior and posterior walls converge on bicipital groove of humerus, which transmits long head of biceps and, more medially, coracobrachialis. • The axilla contains: ∘ Lymph nodes and lymphatic vessels ∘ Axillary artery – Continuation of subclavian artery at lateral border of first rib. – Becomes brachial artery at lower border of teres major. – Divided into three parts by pectoralis minor: • First part (one branch) – superior thoracic • Second part (two branches) – thoracoacromial and lateral thoracic • Third part (three branches) – subscapular, anterior and posterior circumflex humeral. ∘ Axillary vein ∘ Nerves – Cords and branches of brachial plexus; intercostobrachial nerve. – Most are superior to axillary vein – therefore, relatively safe during lymphadenectomy. – The nerves most at risk are: • Intercostobrachial nerve • Long thoracic nerve of Bell • Thoracodorsal nerve • Medial pectoral nerve, particularly if pectoralis minor is resected. 110 Chapter 2 • Levels of the axilla: ∘ Level I: inferolateral to pectoralis minor ∘ Level II: behind pectoralis minor ∘ Level III: superomedial to pectoralis minor. • Superior boundary of dissection is usually the axillary vein. Inguinal dissection • Controversy: whether to only remove nodes inferior to inguinal ligament or proceed into the pelvis with ilioinguinal dissection. • 30–44% of patients with palpable disease inferior to inguinal ligament also have pelvic disease. • No conclusive evidence that removing pelvic lymph nodes improves survival, but it may decrease groin relapse. • UK guidelines advise superficial inguinal dissection (inferior to inguinal ligament) for: ∘ Single clinically involved inguinal node or femoral triangle node. ∘ Single positive superficial inguinal sentinel node. • Indications for considering ilioinguinal dissection: ∘ More than one palpable inguinal or femoral triangle node. ∘ CT/ultrasound evidence of more than one inguinal or femoral triangle node, or pelvic node involvement. ∘ More than one microscopically involved node at SLNB. ∘ Conglomerate of inguinal or femoral triangle lymph nodes. ∘ Microscopic or macroscopic involvement of Cloquet’s node. • Boundaries of the femoral triangle: ∘ Superior: inguinal ligament. ∘ Medial: medial border of adductor longus. ∘ Lateral: medial border of sartorius. ∘ Floor: adductor longus, pectineus and iliopsoas. ∘ Roof: fascia lata, subcutaneous fat including great saphenous vein, skin. • Contains femoral nerve, artery, vein and superficial inguinal lymph nodes. ∘ Mnemonic for the arrangement of neurovascular structures: ‘NAVYVAN’ – The ‘Y’ represents a pair of Y-fronted underpants, separating left from right. • Key points of inguinal dissection: ∘ Longitudinal, lazy-S or transverse skin incision. ∘ Raise thin skin flaps. ∘ Ligation of great saphenous vein. ∘ Dissect fatty and lymphatic tissues from the neurovascular structures. ∘ Consider sartorius switch to cover vessels in case of wound breakdown. ∘ Insert a drain. • For ilioinguinal dissection, the inguinal ligament is divided 2 cm lateral to the femoral artery. • The retroperitoneal space is entered; ureter is protected as it crosses common iliac vessels, close to their bifurcation into internal and external iliac vessels. Skin and Soft Tissue Lesions 111 • A segment of deep inferior epigastric vessels is included in the specimen – they are divided at their origin from external iliac vessels and again at the lateral border of rectus abdominis. • Aim to remove external iliac and obturator nodes in continuity with superficial inguinal nodes. • Boundaries of obturator lymph nodes: ∘ Anterior: external iliac vein ∘ Posterior: obturator nerve ∘ Inferior: obturator foramen ∘ Superior: internal iliac artery. Specific complications of inguinal and axillary lymphadenectomy • Injury to any structure passing through the surgical field. • Numbness (common). • Skin edge necrosis (50%). • Seroma (30%). • Lymphoedema (30%). • Wound infection (25%). Neck dissection • Neck dissection for MM removes levels I–V as a minimum. • Selective neck dissection is not recommended. • Neck dissection is discussed in detail in Chapter 3, ‘Head and neck cancer’. Management of metastatic disease Locoregional recurrent melanoma • Treatment options are palliative: ∘ Surgical excision for solitary lesions. ∘ CO2 laser for multiple small (<1 mm) dermal lesions. ∘ Extensive limb disease may benefit from regional chemotherapy by isolated limb infusion or perfusion. ∘ Consider radiotherapy. Systemic disease Immunotherapy Ipilimumab • Monoclonal antibody; inhibits cytotoxic T-lymphocyte antigen 4 (CTLA-4). ∘ CTLA-4 normally downregulates T-cell activation. ∘ Inhibiting CTLA-4 therefore stimulates the immune system to attack the cancer. • Trials demonstrate improved progression-free survival and overall survival. Interleukin-2 • Arrests growth of metastatic MM for prolonged periods. 112 Chapter 2 • Only 6% of patients obtain durable complete remission. • Potentially life-threatening side effects at doses required for therapeutic effect. Signal transduction inhibitors Vemurafenib • Given orally. • Targets a mutated form of the BRAF gene present in about half of MMs. • Resected MM tissue is first tested to confirm presence of the BRAF V600 mutation. ∘ Without a V600 mutation, vemurafenib stimulates growth of tumour cells. • Increased incidence of cutaneous SCC and KA while on vemurafenib. • Trials demonstrate improved progression-free survival and overall survival. Chemotherapy • The main drug for MM is dacarbazine, an alkylating agent. • Dacarbazine does not provide survival benefit. • Response rates are 10–20% and short-lived, usually <6 months. Palliative local therapy • Metastases to distant lymph node basins can be palliated by lymphadenectomy. • Single metastases can be palliated with resection. • MM is classically radioresistant, but radiotherapy may alleviate symptoms. Important trials in melanoma Surgical excision margins World Health Organisation (WHO) Melanoma Cooperative Group Trial (Veronesi, 1988, 1991) • No difference between 1 and 3 cm margins for MMs ≤2 mm thick. Intergroup Melanoma Surgical Trial (Balch, 1993, 2001) • No difference between 2 and 4 cm margins for MMs 1–4 mm thick. The Swedish trial (Cohn-Cedermark, 2000) • No difference between 2 and 5 cm margins for MMs 0.8–2.0 mm thick. The French trial (Khayat, 2003) • No difference between 2 and 5 cm margins for MMs <2.1 mm thick. The Melanoma Study Group, BAPS and Scottish Cancer Therapy Group trial (Thomas, 2004) • No difference in overall survival between 1 and 3 cm margins for MMs >2 mm thick, but did show higher rate of locoregional recurrence when 1 cm margins were taken. The Swedish and Danish trial (Gillgren, 2011) • No difference between 2 and 4 cm margins for melanomas >2 mm thick. • Does not support 3 cm margins recommended in the 2010 UK guidelines. Skin and Soft Tissue Lesions 113 SLNB Multicenter Selective Lymphadenectomy Trial (MSLT-1) (Morton, 2014) • Patients with intermediate-thickness (1.2–3.5 mm) MMs randomised to one of two treatment groups: 1 Wide local excision and observation of regional lymph nodes, with lymphadenectomy if nodal relapse occurred. 2 Wide local excision and SLNB with immediate lymphadenectomy if nodal micrometastases were detected on biopsy. • Showed sentinel node status to be the most important prognostic factor for recurrence and survival. • Patients with positive SLNB have 62% 10-year survival compared with 85% if SLNB negative. • Reports a 10-year survival advantage in node-positive patients in the SLNB group (62%) versus observation group (42%). Multicenter Selective Lymphadenectomy Trial (MSLT-2) • At the time of writing, this trial is still recruiting patients. • SLNB-positive subjects are randomised to one of two treatment groups: 1 Immediate completion lymphadenectomy 2 Observation with nodal ultrasound. • The primary outcome measure is melanoma-specific survival. • Secondary outcome measures are disease-free survival and recurrence. • Subjects are followed up for 10 years or until death. Ipilimumab and vemurafenib Hodi et al. (NEJM 2010) • Overall survival 10 months for ipilimumab compared to 6.4 months for placebo. Robert et al. (NEJM 2011) • Randomised patients to ipilimumab plus dacarbazine or placebo plus dacarbazine. • Overall survival 11.2 months for ipilimumab compared with 9.1 months for placebo. BRAF Inhibitor in Melanoma 3 (BRIM-3) (Chapman, 2011) • Compared vemurafenib with dacarbazine for metastatic MM. • Vemurafenib associated with 63% relative reduction in risk of death compared to dacarbazine. Vascular anomalies • Generally managed by an MDT of specialists in supraregional centres. Classification • The 2014 International Society for the Study of Vascular Anomalies (ISSVA) classification is based on original work by Mulliken and Glowacki: 114 Chapter 2 1 Vascular tumours Benign • Infantile haemangioma • Congenital haemangioma • Tufted angioma • Spindle-cell haemangioma • Epithelioid haemangioma • Pyogenic granuloma. Locally aggressive or borderline • Kaposiform haemangioendothelioma • Retiform haemangioendothelioma • Papillary intralymphatic angioendothelioma • Composite haemangioendothelioma • Kaposi sarcoma. Malignant • Angiosarcoma • Epithelioid haemangioendothelioma. 2 Vascular malformations Simple • Capillary malformations • Lymphatic malformations • Venous malformations • Arteriovenous malformations∗ • Arteriovenous fistula.∗ Combined • Capillary venous malformation • Capillary lymphatic malformation • Lymphatic venous malformation • Capillary lymphatic venous malformation • Capillary arteriovenous malformation∗ • Capillary lymphatic arteriovenous malformation∗ • Others. Of major named vessels • Anomalies of: ∘ Origin ∘ Course ∘ Number ∘ Length ∗ High flow lesions. Skin and Soft Tissue Lesions ∘ ∘ ∘ ∘ 115 Diameter (aplasia, hypoplasia, stenosis, ectasia/aneurysm) Valves Communication (arteriovenous fistula) Persistence (of embryonal vessel). Associated with other anomalies • Klippel–Trénaunay syndrome • Parkes–Weber syndrome • Sturge–Weber syndrome • Others. • The classification is useful for: ∘ Diagnosis ∘ Planning ∘ Management ∘ Predicting future behaviour of lesions. Vascular tumours Infantile haemangioma • • • • • • • Most common tumour of infancy. Incidence: 10% in white infants; 23% in premature babies with low birthweight (<1 kg). Male:female ratio 1:3. Approximately 80% focal, 20% multifocal. 60% in the head and neck. 1∕3 noticed at birth as a ‘herald patch’; majority appear 2 weeks after birth. Deep-seated tumours may not be noticed until 2–4 months. Classification Pattern • Focal • Multifocal • Segmental • Indeterminate. Type • Superficial • Deep • Mixed (superficial and deep) • Reticular/abortive/minimal growth • Others. Aetiology • Precise cause is not known; possible mechanisms: ∘ Placental embolisation, evidenced by expression of GLUT1 and other placental antigens. ∘ Mutation in an endothelial cell leading to clonal expansion. ∘ Germline mutation, evidenced by hereditary transmission. 116 Chapter 2 Pathogenesis • Natural history divided into three phases: Proliferating phase • Occurs over the course of 6–8 months. • Tumour appears raised, bosselated and deep red. • Deep haemangiomas can take on a blue hue. • Characterised by rapidly dividing endothelial cells that form tightly packed sinusoidal channels. • Increased vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) thought to be responsible for upregulating angiogenesis. Involuting phase • Occurs over the course of 5–10 years. • The deep red colour becomes less vivid; pale patches develop within the lesion. • Regression, decreased endothelial cell activity, luminal enlargement. • Fibrous tissue and other stromal cells are deposited – mast cells, fibroblasts, macrophages. • Increased tissue inhibitor of metalloproteinase (TIMP)-1 suppresses angiogenesis. Involuted phase • Rule of thumb: 50% involuted by 5 years of age, 60% by 6, 70% by 7 … and 100% by age 10 or 12. • Characterised by sparse capillaries and veins with multilaminated basement membranes. • Residual loose fibrofatty tissue often enclosed by stretched, thin, crêpe-like skin. ∘ However, the skin appears near normal in 50% of cases. Associations • Infantile haemangiomas occasionally occur as part of a syndrome or association: ∘ PHACES association – Posterior cranial fossa cystic malformations – Haemangioma on the face, often large and plaque-like – Arterial anomalies – Cardiac defects – Eye anomalies – Sternal cleft/supraumbilical raphe. ∘ Lumbosacral haemangioma associated with occult spinal dysraphism. ∘ Diffuse perineal haemangioma associated with urogenital/anorectal anomalies. Complications 1 Intrinsic to the haemangioma. 2 Due to obstruction of a body orifice. Skin and Soft Tissue Lesions 117 Intrinsic complications • Ulceration (10%) usually occurs in areas subject to repeated trauma, e.g. perineum. ∘ Ulceration is painful; can lead to scarring. • Infection may occur secondary to ulceration. • Severe bleeding is rare, typically caused by trauma; ulceration may cause minor bleeding. Obstructive complications • Obstruction of the visual axis requires urgent treatment to avoid amblyopia. • Visual obstruction can cause deprivational amblyopia: ∘ Attenuated optic nerve transmission to the brain causes abnormal maturation of the visual cortex. – This is not correctable by refraction. • Anisometropia is where the eyes have unequal refractive power. ∘ Can result from direct pressure on the globe, causing deformation or strabismus. ∘ The brain may suppress information received from the problematic eye to prevent double vision. – If the refractive error is not corrected early, this can also lead to amblyopia. • Airway obstruction is a rare complication of cervicofacial haemangioma. ∘ Classically have a ‘beard’ distribution. ∘ Subglottic lesions may present with insidious onset biphasic stridor at 6–8 weeks of age. • External acoustic meatus obstruction is uncommon; results in conductive deafness. Treatment • Indications include: ∘ Obstruction of a vital structure ∘ Ulceration or bleeding due to local trauma ∘ Significant distortion and aesthetic considerations. • Treatment is usually nonoperative: ∘ Observation ∘ Local treatments ∘ Pharmacological agents. Observation • Most haemangiomas are ‘treated’ with observation alone. • Spontaneous involution occurs in 85–90%. • More limited involution may occur at the nasal tip (Cyrano nose) and parotid region. Local treatments • Indicated for ulceration and bleeding. • Bleeding can be stopped with gentle direct pressure. • Ulcerated haemangiomas are painful and cause distress for child and parents. 118 • • • • Chapter 2 Analgesics: paracetamol, oral morphine, intranasal diamorphine. Topical lignocaine gel – be sure not to cause systemic toxicity. Cover ulceration with a thin hydrocolloid dressing, e.g. DuoDERM to reduce pain. Most infections can be treated topically, e.g. mupirocin or metronidazole ointment. Pharmacological agents Propranolol (β-blocker) • Has superseded systemic corticosteroids as the treatment of choice. • Propranolol’s efficacy was a chance discovery, described in 2008 in two children who received the drug for cardiopulmonary conditions. • Now widely used ‘off-label’ to treat infantile haemangioma. • Treatment is usually continued for 12 months to avoid rebound growth. • Propranolol’s side effects can be serious, including: ∘ Hypoglycaemia ∘ Bronchospasm ∘ Hypotension ∘ Hypothermia. • Most centres have treatment protocols involving paediatricians or cardiologists. • Full history, examination, ECG and echocardiogram are required prior to commencing treatment. • Heart rate, blood pressure and blood glucose should be monitored during initiation of treatment. • Absolute contraindications: sick sinus syndrome, 2nd or 3rd-degree heart block. • Relative contraindications: ∘ Impaired cardiac function ∘ Sinus bradycardia ∘ Hypotension ∘ First-degree heart block ∘ Chronic renal insufficiency ∘ PHACES syndrome, where cerebral perfusion can be compromised. • Topical β-blockers, e.g. 0.5% timolol, can be considered for superficial lesions when systemic propranolol is contraindicated. Systemic corticosteroids • Alternative first-line treatment or adjunct to β-blockers. • Treatment may be required for up to 12 months. • Close monitoring required during withdrawal because of rebound growth. • Side effects: ∘ Cushingoid appearance ∘ Irritability ∘ Gastrointestinal upset ∘ Fungal infections ∘ Growth retardation ∘ Hypertension Skin and Soft Tissue Lesions ∘ ∘ 119 Adrenal suppression Immunosuppression – live vaccines should be avoided. Intralesional corticosteroids • Best used on localised superficial haemangioma. • Steroid of choice is triamcinolone; injected at monthly intervals. • Fewer systemic side effects with intralesional treatment. • Injecting periorbital lesions can cause retinal or ophthalmic artery occlusion and eyelid necrosis. • Such lesions are best treated by specialist teams including an ophthalmologist. Vincristine • Reserved for adjunctive treatment of resistant, life-threatening haemangiomas. • Inhibits cellular proliferation. • Usually administered by teams including an oncologist, who is familiar with dosing and side effects. Interferon α-2a • Used for life-threatening haemangiomas resistant to propranolol and steroids. • Not usually given concomitantly with steroids. • Side effects: flu-like illness and spastic diplegia. Imiquimod • Not an accepted treatment, but reportedly accelerates involution. Surgery • Not usually required in the proliferative phase. • Acute debulking or excision is only indicated to preserve critical function after failure to respond to all means of pharmacological treatments. • Most surgery is done during the involuted phase for cosmesis. Laser • Vascular lasers do not penetrate deeply enough to ablate haemangiomas. • Can be used for acute ulceration, or residual telangiectasia after involution. Congenital haemangioma • Rare vascular tumours; completely formed at birth. • Do not rapidly proliferate as infantile haemangiomas do. • Two main types: 1 Rapidly involuting congenital haemangioma (RICH) 2 Noninvoluting congenital haemangioma (NICH). • Both tumours are GLUT1 negative. • Large lesions can cause high-output cardiac failure. ∘ Presents on antenatal ultrasound as hydrops fetalis. 120 Chapter 2 • RICH undergoes accelerated regression after a few weeks; usually complete by 14 months. • NICH does not involute; continues to grow in proportion to the child. Pyogenic granuloma • Acquired lesions composed of proliferative vascular tissue. • Common on face and hands. • May arise following seemingly trivial trauma. • Rapid growth, may bleed, can be confused with cutaneous malignancy. • Easily treated by curettage or excision. • Histological examination excludes malignancy, particularly melanoma. The Kasabach–Merritt phenomenon • Described by two paediatricians in 1940. • Associated with: ∘ Kaposiform haemangioendothelioma ∘ Tufted angioma. • Rare, life-threatening condition – mortality rate up to 30%. • Peak incidence is in early infancy. • Managed in a paediatric intensive care setting. • Characterised by: ∘ Enlarging invasive vascular tumour. ∘ Platelet trapping within the lesion, leading to profound thrombocytopenia. ∘ Secondary consumptive coagulopathy and hypofibrinogenaemia. • Risk of spontaneous internal haemorrhage into any body cavity. Vascular malformations • Occur due to an intrinsic abnormality of development; they are not tumours. • Present at birth; generally grow in proportion to the body. ∘ Can increase in size after weight gain, trauma or hormonal surges of puberty/pregnancy. • Causative genes have been identified in some cases. • Investigation of choice is gadolinium-enhanced MRI. ∘ Assesses flow characteristics and extent of involvement. • CT is useful for intraosseous lesions. • Conventional angiography is used for treatment rather than diagnosis. Simple malformations Capillary malformations (CMs) Cutaneous and/or mucosal CMs • Red macules present at birth. • Usually flat and pale in youth; become raised, nodular and dark with age. • Usually treated with a vascular laser, e.g. pulsed dye laser or KTP. • Results are better if treatment initiated in infancy or childhood. • Most CMs are harmless and confined to the skin. Skin and Soft Tissue Lesions 121 • Some features indicate more extensive involvement: ∘ CMs in the territory of the ophthalmic division of the trigeminal nerve (V) is a feature of Sturge–Weber syndrome. – Associated with ipsilateral leptomeningeal and ocular vascular anomalies. ∘ CMs of either ophthalmic or maxillary division of V is associated with glaucoma. ∘ Midline cephalic or spinal CMs indicate possible encephalocele or spinal dysraphism. Naevus simplex • These lesions are also known as: ∘ Angel kiss ∘ Salmon patch ∘ Stork mark. • Typically occur on the nape of the neck or glabella in 40% of neonates. • Lesions are flat, pale pink and fade slowly; do not usually require treatment. Telangiectasia • May be inherited (hereditary haemorrhagic telangiectasia) or acquired. • Commonly occur on the face, neck, thorax and arms. • Easily treated with a vascular laser. Venous malformations (VMs) Common VMs • Present at birth but may not be noticed until the child is older. • Usually present as a faint blue patch or soft blue compressible mass. • Usually solitary; tend to occur in cutaneous or visceral locations. • Easily compressible and swell when dependant. • May contain phleboliths; recurrent episodes of thrombosis can occur. ∘ Use of limb compression garments minimises risk of painful thrombosis. • Enlargement during puberty is well described. • There is a risk of disseminated intravascular coagulation with very large lesions: ∘ Platelets and PT/APTT may be normal, but fibrinogen is low with increased levels of fibrin degradation products (unlike Kasabach–Merritt phenomenon). • Treatment is indicated on functional or aesthetic grounds: ∘ Small cutaneous VMs can be sclerosed with 1% sodium tetradecyl sulphate. ∘ Large deep VMs require treatment by experienced specialists, under general anaesthesia with fluoroscopic monitoring. – The sclerosant of choice for these cases is absolute ethanol. – Ethanol may cause nerve damage, so 3% sodium tetradecyl sulphate may be used in high risk areas. • Complications of sclerotherapy: ∘ Local effects: blistering, necrosis, nerve deficit. ∘ Systemic effects: cardiac arrest, renal toxicity. • Surgical debulking, if required, is done after completion of sclerotherapy. • Conditions associated with VMs: 122 Chapter 2 Blue rubber bleb naevus (BRBN) syndrome • Characterised by multiple VMs of skin and viscera. • Rare, but significant for causing intestinal haemorrhage, which can be fatal. Multiple cutaneous and mucosal venous malformations (also known as VMCM) • Characterised by small, multifocal bluish cutaneous and/or mucosal VMs. • Autosomal dominant; accounts for 1% of all VMs seen in specialist centres. • Small lesions are asymptomatic; larger lesions can invade muscle, causing pain. Lymphatic malformations (LMs) • Common (cystic) LMs are classified as: ∘ Microcystic ∘ Macrocystic ∘ Mixed cystic. • Most are evident at birth or detected within the first 2 years. • Soft tissue and bony hypertrophy can occur. • Expand and contract depending on movement of lymphatic fluid. • Sudden enlargement can be caused by intralesional bleeding or infection. ∘ Managed conservatively with analgesia, antibiotics and rest. • Mainstay of treatment is sclerotherapy. • Large cystic areas can be aspirated, followed by instillation of sclerosant, e.g. absolute ethanol, sodium tetradecyl sulphate, doxycycline, OK-432. • Localised disease may be amenable to curative surgery. • Diffuse disease requires complex, staged surgery, where blood loss may be measured in ‘number of blood volumes replaced’. • Complications of surgery: ∘ Infection ∘ Haematoma ∘ Prolonged drainage ∘ Incomplete excision and recurrence. • Primary lymphoedema is also a form of LM, discussed in Chapter 6, ‘Lymphoedema’. Arteriovenous malformations (AVMs) • Usually present at birth but only become apparent in infancy or childhood. • Commoner intracranially than extracranially. • The epicentre or nidus is a compact tangle of dysplastic, thin-walled vessels, connecting feeding arteries to ectatic draining veins via numerous micro- and macroarteriovenous fistulas. • Trauma or puberty triggers expansion, manifest by: ∘ Darkening of overlying skin to a red or violaceous colour ∘ Enlargement of the lesion, palpable as a mass ∘ Local warmth, bruit and thrill. • Sequelae of expansion: ∘ Ischaemic skin changes Skin and Soft Tissue Lesions ∘ ∘ ∘ ∘ 123 Ulceration Bleeding Significant pain Increased cardiac output (very large lesions). Classification • Sporadic • In hereditary haemorrhagic telangiectasia • In CM-AVM • Others. Staging • Schobinger described a clinical staging system: ∘ Stage I: Quiescence – a pink-blush stain with warmth. ∘ Stage II: Expansion – a mass associated with a bruit and thrill. ∘ Stage III: Destruction – a mass associated with ulceration, bleeding and pain. ∘ Stage IV: Decompensation – stage III plus heart failure. Treatment • Notoriously difficult to treat. • Treatment is targeted at the nidus. • Intervention is usually indicated for Schobinger III and IV lesions. • Extent of disease is delineated with MRI or MR angiography. • Conventional angiography is only done when therapeutic embolisation is planned. • Ligation or embolisation of proximal feeding arteries should not be done. ∘ This limits endovascular access to the nidus and recruits more collaterals. • Superselective angiography and embolisation of the nidus is done 24–72 hours prior to planned surgical resection. • Wide excision aims to remove all involved tissues, including overlying skin if abnormal. • Curative resection is not usually achievable. Malformations associated with other anomalies Klippel–Trénaunay syndrome (KTS) • Combined capillary-lymphaticovenous malformation associated with soft tissue and skeletal hypertrophy in one or more limbs. ∘ Rarely, it is associated with limb undergrowth. • Most common in the anterolateral thigh, buttock and trunk. • Venous anatomy often aberrant and complex. • Specialist assessment is required prior to any treatment. Parkes–Weber syndrome • Combined capillary lymphatic arterial venous malformation; presents at birth. • Lower limb is usually affected. • Angiography shows multiple microscopic arteriovenous fistulae throughout the affected limb. 124 Chapter 2 Soft tissue tumours • ‘Soft tissue’ is defined as nonepithelial extraskeletal tissue: ∘ Muscle ∘ Fat ∘ Fibrous tissue ∘ Vessels. • By convention, peripheral nerves are also defined as soft tissue. Classification of soft tissue tumours • Benign • Malignant • Tumours of intermediate malignancy. Benign • Resemble normal tissue: ∘ Lipoma ∘ Leiomyoma ∘ Rhabdomyoma ∘ Lymphangioma ∘ Schwannoma. • Limited capacity for autonomous growth. • Not locally invasive; low rate of recurrence following treatment. Malignant • Known as sarcomas. • Locally invasive; can metastasise. • Prone to recurrence; require radical treatment. Tumours of intermediate malignancy • These are tumours of borderline or low malignant potential. • May have high local recurrence rate but low risk of metastasis. • Examples: ∘ Dermatofibrosarcoma protuberans (DFSP) ∘ Kaposiform haemangioendothelioma ∘ Atypical lipoma ∘ Haemangiopericytoma. Sarcoma • ‘Sarcoma’ derives from the Greek, meaning ‘fleshy growth’. • Whilst the majority of malignancies (carcinomas) arise from epithelial tissues, malignant tumours arising from mesoderm, e.g. bone and muscle, are sarcomas. • By convention, peripheral nerve malignancies are also defined as sarcomas, despite being of ectodermal origin. Skin and Soft Tissue Lesions 125 Epidemiology • 1% of all malignant tumours; affect 20 per million per year. • Soft tissue sarcomas (STSs) gradually increase in incidence with age. ∘ In contrast, bone sarcomas have a clear bimodal incidence. • 75% of STSs occur in the lower extremity, mostly in the thigh. ∘ Other sites: trunk, retroperitoneum, viscera, head and neck. Aetiology • Most are sporadic. • Potential causative factors: ∘ Genetic – NF-1: up to 10% lifetime risk of malignant transformation. – Gardner syndrome (familial polyposis coli): associated with desmoid tumours. – Hereditary retinoblastoma survivors: increased risk of STS. – Gorlin’s syndrome: associated with fibrosarcoma and rhabdomyosarcoma. – Li Fraumeni syndrome (germline mutation in p53): increased risk of STS. ∘ Radiation ∘ Chronic lymphoedema: associated with lymphangiosarcoma. ∘ Chronic burn scar. ∘ Chemical exposure: phenoxyacetic herbicides, Agent Orange, arsenic. ∘ Viral infection: herpes virus or HIV associated with Kaposi sarcoma; Epstein–Barr virus (EBV) associated with smooth muscle sarcoma. Clinical presentation • Typically presents as a painless lump. • Other symptoms depend on location and structures distorted by the tumour. • Certain features of a lump strongly suggest a diagnosis of sarcoma: 1 Size >5 cm 2 Deep to deep fascia 3 Pain 4 Increasing size. • The greater number of cardinal features, the greater the risk of malignancy: ∘ One – 16%; two – 43%; three – 65%; four – 86%. • A tumour that recurs following excision also raises possibility of malignancy. • Suspected sarcomas should be referred urgently to a specialist sarcoma MDT. • The MDT will plan appropriate imaging, biopsy and ongoing treatment. • Attempts at biopsy or treatment by nonspecialists usually results in inadequate surgery and treatment delay. Diagnostic pathway 1 Clinical assessment ∘ Extent of resection required ∘ Regional lymphadenopathy (rare in sarcoma) ∘ Reconstruction required. 126 Chapter 2 2 Radiological assessment ∘ Localises and characterises the tumour. ∘ Stages the disease. ∘ CT assesses the primary tumour and any metastatic disease. ∘ MRI differentiates fat and nonfat tumours; excellent soft tissue detail. ∘ PET is sensitive for most sarcomas. ∘ USS used for targeted biopsy. ∘ Imaging is usually done before biopsy to minimise artefact from bleeding or oedema. 3 Biopsy ∘ Percutaneous core biopsy, reviewed by a specialist sarcoma histopathologist, is the procedure of choice. ∘ Ultrasound or CT guidance can target areas of interest within the tumour mass. – Also helps avoid passing through uninvolved muscle compartments. ∘ Open biopsy is indicated after failed core biopsy. – This transgresses compartment boundaries and may upstage the tumour. ∘ Biopsies, incisions and drain sites are placed within the zone of future excision. 4 Planning ∘ Neoadjuvant and adjuvant therapies. ∘ Surgery and reconstruction. Classification • Sarcomas are classified by: ∘ Histological type ∘ TNMG classification ∘ Stage. Histological type • Pathology reference manuals are replete with types and subtypes of sarcoma. • Selected examples: ∘ Smooth muscle – leiomyosarcoma ∘ Striated muscle – rhabdomyosarcoma ∘ Fat – liposarcoma ∘ Blood and lymph vessels – angiosarcoma, Kaposi sarcoma ∘ Fibrous tissue – malignant fibrous histiocytoma (MFH) ∘ Nerve – malignant peripheral nerve sheath tumour (MPNST) – Malignant triton tumour (MTT) – a histological variant of MPNST with rhabdomyosarcomatous differentiation ∘ Synovium – synovial sarcoma ∘ Skin – atypical fibroxanthoma (AFX). • The most common sarcomas in the United Kingdom are MFH (28%), liposarcoma (15%), leiomyosarcoma (12%). TNMG classification Primary tumour (T) • Tx: Primary tumour cannot be assessed • T0: No evidence of primary tumour Skin and Soft Tissue Lesions 127 • T1: Tumour ≤5 cm ∘ a: Superficial tumour ∘ b: Deep tumour • T2: Tumour >5 cm ∘ a: Superficial tumour ∘ b: Deep tumour • (Superficial tumour is superficial to fascia). Regional lymph nodes (N) • Nx: Regional lymph nodes cannot be assessed. • N0: No regional lymph node metastasis. • N1: Regional lymph node metastasis. Distant metastasis (M) • M0: No distant metastasis • M1: Distant metastasis. Trojani grade (G) • Based on number of mitoses, presence of necrosis, degree of differentiation. • G1: low-grade tumour • G2: intermediate-grade tumour • G3: high-grade tumour. Clinical staging Stage T N M G Stage IA T1a T1b T2a T2b T1a T1b T2a T2b T2a, T2b Any T Any T N0 N0 N0 N0 N0 N0 N0 N0 N0 N1 Any N M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M1 G1 G1 G1 G1 G2, G3 G2, G3 G2 G2 G3 Any G Any G Stage IB Stage IIA Stage IIB Stage III Stage IV Surgical management Planning • Planning treatment requires knowledge of a sarcoma’s typical behaviour. • Most have a centrifugal growth pattern. • Compression of surrounding soft tissue produces a ‘pseudocapsule’ around the tumour. ∘ This is a reactive zone surrounding the tumour, harbouring nests of tumour cells. 128 Chapter 2 • Nonspecialists may find a tumour ‘shells out’, implying a well-defined border. ∘ For sarcomas, this inevitably leaves viable tumour cells within the pseudocapsule. • Sarcomas usually respect fascial boundaries until late in their progression. • These factors are taken into account when planning excision. Excision margins • Two main systems in use: 1 AJCC residual tumour (R) classification – Describes tumour status following treatment. – Includes lymph nodes and sites of distant metastases. • R0 – no residual tumour • R1 – microscopic residual tumour • R2 – macroscopic residual tumour. 2 Enneking classification Intralesional • Describes the ‘shell out’ procedure. • Macroscopic tumour is left behind; recurrence is close to 100%. Marginal • The pseudocapsule forms the periphery of the resection specimen. • Microscopic disease is left within the reactive zone; recurrence is 40–60%. Wide • Removes the tumour and pseudocapsule with a margin of nonreactive normal tissue. • Risks leaving microscopic skip lesions; more likely with high-grade lesions. • Recurrence rates approximately 10%. Radical • Removes all normal tissue of the compartment involved with tumour. • Muscles are excised en bloc, from origin to insertion, including fascial sheaths. • In theory, leaves no residual disease; local recurrence rate 0.5%. Amputation versus limb salvage • Amputation is considered when critical structures must be resected, which would otherwise leave a poorly functioning limb. • Limb salvage strategies have reduced amputation rates to about 5% of cases. • Limb salvage requires a multimodal approach to achieve low recurrence: ∘ Neoadjuvant radiotherapy or, less commonly, chemotherapy ∘ Resection – Aim for a wide margin while preserving critical neurovascular structures. ∘ Reconstruction – Functional reconstruction with nerve grafts, nerve transfers, vascular reconstruction and free functioning muscle transfer. ∘ Adjuvant radiotherapy or, less commonly, chemotherapy. Skin and Soft Tissue Lesions 129 Prognosis • Overall survival is 50–60%. • Prognostic factors: age, metastasis at presentation, tumour size and depth. • Histological grade is the critical determinant of prognosis: ∘ Low grade (Trojani 1): 90% 5-year survival. ∘ High grade (Trojani 2 and 3): 50–60% 5-year survival without metastases; <10% with metastases. • Metastasis mainly occurs via the haematogenous route. • Pulmonary metastatectomy may be beneficial in young patients with a low-grade primary. • Lymph node involvement is as ominous as lung metastasis, but uncommon. Exceptions and special situations Chemosensitive tumours • Paediatric rhabdomyosarcoma, soft tissue Ewing’s sarcoma and synovial sarcoma are all chemosensitive. • The preferred treatment algorithm for these tumours is: ∘ Neoadjuvant chemotherapy ∘ Surgery, with or without radiotherapy ∘ Further adjuvant chemotherapy. Children • Children with metastatic disease, on the whole, fare better than adults. • Radiotherapy has a greater risk of long-term sequelae in children. • Chemotherapy may cause infertility. Isolated limb perfusion • Controversial treatment for unresectable extremity sarcoma. • Used to reduce the extent of extremity sarcoma in an effort to avoid amputation. • Also used for extensive locoregional metastases. Cutaneous sarcomas • Primary tumours originate in skin; managed similar to other skin cancer. ∘ Surgical excision is the mainstay of treatment. ∘ Imaging rarely required without clinical evidence of metastasis. • Secondary tumours are skin metastases from cutaneous or noncutaneous sarcomas. Malignant fibrous histiocytoma (MFH) • Rare aggressive tumour; presents as a firm subcutaneous nodule in the elderly. ∘ Also known as pleomorphic undifferentiated sarcoma. • Commonly affects the thigh, upper limb and retroperitoneum. • 2∕3 located in skeletal muscle; <10% confined to subcutis. • Treated by wide excision or Mohs surgery; consider adjuvant radiotherapy. • Prone to local recurrence; 30% develop distant metastases. 130 Chapter 2 Atypical fibroxanthoma (AFX) • The superficial cutaneous counterpart of MFH. ∘ Also known as pleomorphic undifferentiated sarcoma of skin. • Starts as small, firm cutaneous nodules. • Usually occurs on head and neck of older patients, in sun-damaged or irradiated skin. • Histology is indistinguishable from MFH – aggressive, poorly differentiated lesion. ∘ However, unlike MFH, prognosis is usually excellent. • AFX rarely recurs after wide excision with clear margins. Angiosarcoma • Aggressive, often multicentric tumour; typically occurs on face and scalp of the elderly. • At presentation, it usually extends beyond its clinical margins. • High rate of local recurrence and metastasis. • Surgical margins of 5 cm, where anatomically feasible, are suggested. Dermatofibrosarcoma protuberans (DFSP) • A tumour of intermediate malignancy. ∘ Prone to local recurrence but rarely metastasises. • Slow-growing, red-brown nodule, most common on the trunk. • Mean age of presentation is 35 years. • Pathogenesis involves a distinctive rearrangement of chromosomes 17 and 22. • Excised with a wide margin of at least 2–3 cm down to deep fascia. • Despite wide excision, local recurrence rates are reportedly 15%. ∘ Recurrence rates as low as 1.3% are reported with Mohs. • Imatinib is a tyrosine kinase inhibitor – useful neoadjuvant treatment of inoperable, metastatic or recurrent DFSP. Bone sarcomas • Rare; affect <500 people per year in the United Kingdom. • Most common bone sarcomas: ∘ Osteosarcoma ∘ Ewing’s sarcoma ∘ Chondrosarcoma. Treatment • Investigated and managed in specialist bone sarcoma centres. • Treatment broadly involves: ∘ Neoadjuvant therapy (chemotherapy ± radiotherapy) ∘ Surgical resection and reconstruction ∘ Postoperative adjuvant therapy, determined by surgical margins and histology. Reconstruction • Reconstruction of long bones can be achieved by: ∘ Bespoke prostheses Skin and Soft Tissue Lesions 131 ∘ ∘ Allograft bone Extracorporeal radiotherapy. – Involved bone is resected, including the tumour. – The tumour is excised from the bone after its removal from the patient. – The remaining bone is irradiated to 90 cGy, which avoids collateral soft tissue damage that would occur with traditional external beam radiotherapy. – The irradiated bone is reinserted as a graft. • Vascularity of both allograft and irradiated autologous bone graft can be augmented with free vascularised bone from the fibula. ∘ Known as the Capanna technique. ∘ The diaphysis of the long bone is reamed to accept the fibula. Further reading Benign skin lesions Christoffersen M, Frikke-Schmidt R, Schnohr P et al. Xanthelasmata, arcus corneae, and ischaemic vascular disease and death in general population: prospective cohort study. BMJ 2011;343:d5497. Kinsler V, Bulstrode N. The role of surgery in the management of congenital melanocytic naevi in children: a perspective from Great Ormond Street Hospital. J Plast Reconstr Aesthet Surg 2009;62(5):595–601. Ludgate MW, Fullen DR, Lee J et al. The atypical Spitz tumor of uncertain biologic potential: a series of 67 patients from a single institution. Cancer 2009;115(3):631–41. BCC Telfer NR, Colver GB, Morton CA; British Association of Dermatologists. Guidelines for the management of basal cell carcinoma. Br J Dermatol 2008;159(1):35–48. Whitaker IS, Shokrollahi K, James W et al. Combined CO2 laser with photodynamic therapy for the treatment of nodular basal cell carcinomas. Ann Plast Surg 2007;59(5):484–8. SCC Motley RJ, Preston PW, Lawrence CM; British Association of Dermatologists. Multi-professional guidelines for the management of the patient with primary cutaneous squamous cell carcinoma. 2009. http://www.bad.org.uk (last accessed 13th July 2014). MCC Bichakjian CK, Lowe L, Lao CD et al. Merkel cell carcinoma: critical review with guidelines for multidisciplinary management. Cancer 2007;110(1):1–12. Feng H, Shuda M, Chang Y et al. Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science 2008;319(5866):1096–100. MM Balch CM, Soong SJ, Bartolucci AA et al. Efficacy of an elective regional lymph node dissection of 1 to 4 mm thick melanomas for patients 60 years of age and younger. Ann Surg 1996;224(3):255–63. 132 Chapter 2 Balch CM, Soong SJ, Smith T et al.; Investigators from the Intergroup Melanoma Surgical Trial. Long-term results of a prospective surgical trial comparing 2 cm vs. 4 cm excision margins for 740 patients with 1–4 mm melanomas. Ann Surg Oncol 2001;8(2):101–8. Chapman PB, Hauschild A, Robert C et al.; BRIM-3 Study Group. Improved survival with vemurafenib in melanoma with BRAF V600E mutation. N Engl J Med 2011;364(26):2507–16. Cohn-Cedermark G, Rutqvist LE, Andersson R et al. Long term results of a randomized study by the Swedish Melanoma Study Group on 2-cm versus 5-cm resection margins for patients with cutaneous melanoma with a tumor thickness of 0.8–2.0 mm. Cancer 2000;89(7):1495–501. Gillgren P, Drzewiecki KT, Niin M et al. 2-cm versus 4-cm surgical excision margins for primary cutaneous melanoma thicker than 2 mm: a randomised, multicentre trial. Lancet 2011;378(9803):1635–42. Hodi FS, O’Day SJ, McDermott DF et al. Improved survival with ipilimumab in patients with metastatic melanoma. N Engl J Med 2010;363(8):711–23. Khayat D, Rixe O, Martin G et al.; French Group of Research on Malignant Melanoma. Surgical margins in cutaneous melanoma (2 cm versus 5 cm for lesions measuring less than 2.1-mm thick). Cancer 2003;97(8):1941–6. Marsden JR, Newton-Bishop JA, Burrows L et al.; British Association of Dermatologists (BAD) Clinical Standards Unit. Revised UK guidelines for the management of cutaneous melanoma 2010. J Plast Reconstr Aesthet Surg 2010;63(9):1401–19. Morton DL, Thompson JF, Cochran AJ et al.; MSLT Group. Final trial report of sentinel-node biopsy versus nodal observation in melanoma. N Engl J Med 2014;370(7):599–609. Robert C, Thomas L, Bondarenko I et al. Ipilimumab plus dacarbazine for previously untreated metastatic melanoma. N Engl J Med 2011;364(26):2517–26. Thomas JM, Newton-Bishop J, A’Hern R et al.; United Kingdom Melanoma Study Group; British Association of Plastic Surgeons; Scottish Cancer Therapy Network. Excision margins in high-risk malignant melanoma. N Engl J Med 2004;350(8):757–66. Veronesi U, Cascinelli N. Narrow excision (1 cm margin). A safe procedure for thin cutaneous melanoma. Arch Surg 1991;126(4):438–41. Vascular anomalies Léauté-Labrèze C, Dumas de la Roque E, Hubiche T et al. Propranolol for severe hemangiomas of infancy. N Engl J Med 2008;358(24):2649–51. Mulliken JB, Glowacki J. Hemangiomas and vascular malformations in infants and children: a classification based on endothelial characteristics. Plast Reconstr Surg 1982;69(3):412–20. ISSVA classification for vascular anomalies (approved at the 20th ISSVA Workshop, Melbourne, April 2014). http://www.issva.org (last accessed 13th July 2014). Soft tissue sarcoma Enneking WF, Spanier SS, Malawer MM. The effect of the anatomic setting on the results of surgical procedures for soft parts sarcoma of the thigh. Cancer 1981;47(5):1005–22. Hollmig ST, Kirkland EB, Henderson MT et al. The evolving conception and management challenges of malignant fibrous histiocytoma. Dermatol Surg 2012;38(12):1922–9. Misra A, Mistry N, Grimer R et al. The management of soft tissue sarcoma. J Plast Reconstr Aesthet Surg 2009;62(2):161–74. CHAPTER 3 The Head and Neck CHAPTER CONTENTS Embryology, 133 Dental terminology, 137 Craniofacial surgery, 138 Cleft lip; cleft lip and palate, 160 Cleft palate, 171 Velopharyngeal insufficiency, 177 Head and neck cancer, 180 Maxillofacial trauma, 209 Oculoplastic surgery, 228 Facial palsy, 244 Abnormalities of the ear, 254 Further reading, 261 Embryology ‘Branchia’ is the Greek word for ‘gills’. Branchial arches are paired swellings along the pharynx of a 4-week-old embryo. Humans have six paired branchial arches, but the fifth disappears. Each branchial arch contains neural crest cell derivatives: ∘ A cartilage ∘ A cranial nerve ∘ An aortic arch ∘ Myoblasts. • First and second branchial arches are most important in facial development. • Grooves between the arches on their external surfaces are called branchial clefts. ∘ The cleft between the first and second arch becomes the external auditory meatus. ∘ The other three clefts disappear. • Grooves between the arches on their inner surfaces are called pharyngeal pouches, which form: ∘ First pouch: tubotympanic recess (middle ear, Eustachian tube) ∘ Second pouch: palatine tonsils ∘ Third pouch: inferior parathyroids, thymus ∘ Fourth pouch: superior parathyroids ∘ Fifth pouch (ultimobranchial body): parafollicular cells of the thyroid. • • • • Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 133 134 Chapter 3 The first branchial arch • Supplied by the trigeminal nerve and maxillary artery. • Also known as the mandibular arch, it gives rise to: ∘ Paired mandibular prominences that contain Meckel’s cartilage. – This mostly resorbs, but its posterior part forms the malleus. – The body and ramus of the mandible form from dermal mesenchyme adjacent to Meckel’s cartilage. ∘ Paired maxillary prominences that form: – Premaxilla – Maxilla – Zygoma – Squamous portion of the temporal bone. ∘ The quadrate cartilage lies within the maxillary prominence. – Forms the incus and greater wing of sphenoid. • Mesenchyme of this arch forms: ∘ Muscles of mastication ∘ Anterior belly of digastric ∘ Mylohyoid ∘ Tensor veli palatini ∘ Tensor tympani. – These are all supplied by the trigeminal nerve. The second branchial arch • Supplied by the facial nerve and stapedial artery. • Also known as the hyoid arch, it contains Reichert’s cartilage, which forms: ∘ Stapes ∘ Syloid process ∘ Lesser cornu and part of the body of the hyoid. • Mesenchyme of this arch forms: ∘ Muscles of facial expression ∘ Posterior belly of digastric ∘ Stapedius ∘ Stylohyoid. – These are all supplied by the facial nerve. The frontonasal process • Formed by proliferation of mesoderm ventral to the forebrain. ∘ Not a branchial arch derivative. • Develops paired placodes (ectodermal thickenings) on its inferolateral borders: ∘ Medial part of the placode forms the medial nasal process. ∘ Lateral part of the placode forms the lateral nasal process. • Between the two appears the nasal pit; this becomes the nostril. • Merging of the medial nasal processes forms: ∘ The philtrum and Cupid’s bow of the upper lip ∘ Nasal tip The Head and Neck 135 ∘ ∘ Nasal septum Premaxilla. • The lateral nasal processes form the nasal alae. Facial development • Mainly occurs between 4th and 8th weeks of intrauterine life. • The face is formed from five facial prominences: ∘ Paired maxillary processes ∘ Paired mandibular processes ∘ Frontonasal process. • The medial nasal process fuses with the maxillary process. ∘ Failure results in cleft lip (CL). ∘ Bilateral failure of fusion results in a bilateral CL. • Failure of midline fusion of the medial nasal processes results in a median CL or Tessier 0 cleft. • The lateral nasal process fuses with the maxillary process at the alar groove. ∘ Failure of fusion results in a Tessier 3 cleft. • Failure of fusion between maxillary and mandibular processes results in macrostomia or Tessier 7 cleft. • Fibroblast growth factors (FGFs), bone morphogenetic proteins (BMPs), sonic hedgehog (SHH) and retinoic acid have all been implicated. Cranial development • Bones of the skull base develop from cartilage precursors, including: ∘ Sphenoid, ethmoid, petrous temporal and basioccipital. • Bones of the cranial vault develop in membrane derived from the presumptive dermis, including: ∘ Frontal, parietal, squamous temporal and squamous occipital. • At birth, seams of connective tissue called sutures separate the skull bones. • Where more than two bones meet, there is a wider gap called a fontanelle. ∘ The posterior fontanelle closes by 3 months. ∘ The anterior fontanelle normally remains open until 18 months. • These fibrous connections allow the skull to deform during childbirth. • Expansion of the skull is driven by brain growth. • Brain growth stimulates new bone formation at the suture front. ∘ Hydrocephalus causes persisting suture patency. ∘ Microcephaly causes premature suture closure. • The dura plays a key role in controlling suture patency. The neural crest • Just prior to fusion of the neural tube, a population of cells known as the neural crest is generated in the area of the neural folds. 136 Chapter 3 • The neural crest contains pluripotential ectomesenchymal tissue. ∘ Although derived from ectoderm, they exhibit properties of mesenchyme. • These cells migrate throughout the body. • They are prevalent within the facial primordia and are essential for normal craniofacial development. • Teratogens, such as retinoic acid and alcohol, affect neural crest migration. • Neural crest derivatives encompass: ∘ The endocrine system, including the adrenal medulla ∘ The melanocytic system ∘ Connective tissue, including teeth and bone ∘ Muscle tissue ∘ Neural tissue, including the autonomic nervous system. Developmental terminology and definitions Malformation • A morphological defect due to an intrinsic abnormality of development. • Most common types include: ∘ Incomplete morphogenesis, such as microcephaly. ∘ Incomplete closure, such as cleft palate (CP). ∘ Incomplete separation, such as syndactyly. • Malformations initiated earlier in fetal development tend to be more severe. Deformation • An abnormality of form or position of a body part due to intrauterine mechanical forces that restrict movement of the developing fetus. • Deformations can arise from oligohydramnios, bicornuate uterus or twin pregnancy. • Central nervous system (CNS) malformations can cause deformations due to paralysis. Disruption • A defect caused by interference with otherwise normal development. • In utero amputation of a limb due to an amniotic band is a disruption. Sequence • Where a single developmental defect results in a chain of secondary defects. • Secondary defects may cause further tertiary defects. • The result is a group of defects traceable to an originating event. • The primary defect in Pierre Robin sequence (PRS) is mandibular hypoplasia. • The secondary defect is posterior displacement of the tongue. • This blocks closure of the palatal shelves resulting in a tertiary defect: CP. Syndrome • A group of anomalies (symptoms and signs) containing multiple malformations or sequences. • Collectively they indicate or characterise a particular syndrome. • In Greek, syn is with; dromos is running. The Head and Neck 137 Association • A group of anomalies not known to be part of a syndrome or sequence but found in multiple patients. ∘ Examples include VATER and CHARGE. • Not specific diagnoses, but alert clinicians to search for other components of the association. Dental terminology • • • • • • • • • • • • Primary dentition is the first set of 20 ‘baby’ or ‘deciduous’ teeth. Permanent dentition refers to the 32 secondary ‘adult’ teeth. There are two dental arches: maxillary or upper; mandibular or lower. Arches are divided into quadrants by the midline, e.g. maxillary right quadrant. Teeth are classified by their morphology: ∘ Incisors have an incisal edge. ∘ Canines or cuspids have one pointed cusp. ∘ Premolars or bicuspids have two cusps. ∘ Molars have three or more flattened cusps. Tooth position can be recorded as follows: ∘ Descriptive, e.g. ‘right upper second molar’. ∘ Palmer notation, the most popular method in the United Kingdom: – Teeth are numbered according to their position from the midline. – Baby teeth are assigned a letter from A to E. – Addition of a symbol (⌟ ⌞ ⌝ ⌜) indicates the quadrant. ∘ The universal numbering system is commonly used in the United States. – Teeth are numbered from 1 to 32, starting at the right maxillary third molar. – The maxillary arch is numbered 1–16. – The mandibular arch is numbered 17–32, starting at the left mandibular third molar. – Baby teeth are assigned a letter from A to T. Teeth have a crown above the gum line and a root below. A cusp is a pronounced elevation on the occlusal surface. A groove delineates the boundary between adjacent cusps. Direction is expressed as follows: ∘ Buccal: towards the cheek ∘ Labial: towards the lips ∘ Lingual: towards the tongue ∘ Palatal: towards the hard palate ∘ Mesial: towards the median line, following the curve of the dental arch ∘ Distal: away from the median line, following the curve of the dental arch ∘ Apical: towards the apex of the root ∘ Occlusal: towards the biting surface of a posterior tooth ∘ Proximal surfaces are those between adjacent teeth. Malocclusion is an incorrect relationship between the teeth of the two dental arches. Angle classified malocclusion based on a relationship where the mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar. 138 Chapter 3 • Normal occlusion has this molar relationship, with normal alignment of the remaining teeth. • Class I malocclusion has a normal molar relationship, but there may be overcrowding or misalignment of the other teeth. • Class II malocclusion has a molar relationship where the buccal groove of the mandibular first molar is distally positioned (away from the median line) from the mesiobuccal cusp of the maxillary first molar. • Class III malocclusion has a molar relationship where the buccal groove of the mandibular first molar is mesially positioned (towards the median line) from the mesiobuccal cusp of the maxillary first molar. • Overbite is the amount of vertical overlap of the mandibular anterior teeth by the maxillary anterior teeth. • Overjet is the horizontal distance between the maxillary incisors and the mandibular incisors. • Open bite is lack of vertical overlap of the maxillary and mandibular anterior teeth or no contact between the maxillary and mandibular posterior teeth. • Cross bite is a discrepancy in the buccolingual relationship of the maxillary and mandibular teeth. Craniofacial surgery Classification • In 1981, the American Cleft Palate Association published the following classification of craniofacial abnormalities: 1 Clefts (centric, acentric) 2 Synostoses (symmetric, asymmetric) 3 Atrophy–hypoplasia 4 Neoplasia–hyperplasia 5 Unclassified. • Some conditions fit into more than one category: ∘ Treacher Collins syndrome is not only associated with facial clefts, but also with facial hypoplasia. Clefts Craniofacial clefts are rare. Also known as ‘atypical’ clefts, as distinguished from ‘typical’ CL and palate. Occur sporadically once in every 25,000 live births. Two leading theories of pathogenesis: ∘ Classic theory – failure of fusion of the facial prominences. ∘ Mesodermal penetration theory – lack of mesodermal penetration leads to dehiscence of the epithelial elements. • Clefts may also arise from intrauterine compression by amniotic bands. • Identification of the genetic basis of craniofacial syndromes is a rapidly expanding field. • Environmental causes include: 1 Radiation • • • • The Head and Neck • • • • • • • 139 2 Infections – Maternal infection with toxoplasmosis, rubella or cytomegalovirus. 3 Maternal – Diabetes, phenylketonuria, maternal age, weight and general health. 4 Chemicals – Folic acid deficiency. – Vitamin A derivatives, such as isotretinoin. Overlap exists between clefts and other hypoplastic syndromes. Treacher Collins syndrome is a hypoplastic condition of the lateral face. ∘ Also known as a confluent Tessier 6,7,8 cleft – has features found in all three cleft patterns. Clefts can affect any or all layers of the face. They may be unilateral or bilateral. Bilateral cases may present different clefts on each side. Soft tissue defects do not always correspond to the bony abnormality. Craniofacial clefts are often associated with hairline markers. ∘ These are areas of abnormal linear hair growth along the cleft. Classification 1 Anatomical – Tessier’s classification. 2 Embryological – Van der Meulen’s classification. Tessier’s classification • The most commonly used and internationally accepted. • Facial clefts extend downwards from the level of the orbit. • Cranial clefts extend upwards from the level of the orbit. • A midline cleft is numbered 0. • Facial clefts are numbered 1–7. ∘ Start near the midline with a Tessier 1. ∘ Each sequential facial cleft is more lateral than the last. ∘ Tessier 7 is the most lateral, extending outwards from the corner of the mouth. • Cranial clefts are numbered 8–14. ∘ Tessier 8 is the most lateral and extends into the corner of the orbit. ∘ Thereafter, each sequential cranial cleft is more medial than the last. • Facial and cranial clefts can be connected. ∘ If this occurs, the patterns tend to add up to 14, e.g. 12 + 2. • Tessier 30 is a midline cleft of the lower lip and mandible. • David Fisher, from the Hospital for Sick Children in Toronto, rationalises Tessier’s classification as follows: ∘ ‘Think in groups of three’: – 0,1,2: lip to nose – 3,4,5: lip to orbit/lower eyelid – 6,7,8: Treacher Collins – 9,10,11: Orbit and upper lid – 12,13,14: Medial to orbit. ∘ Tessier 3 involves 4 cavities: oral, maxillary sinus, nasal and orbital. 140 ∘ ∘ ∘ ∘ ∘ ∘ Chapter 3 Tessier 4 involves 3 cavities: oral, maxillary sinus and orbital. Tessier 4 is medial to the infraorbital foramen. Tessier 5 is lateral to the infraorbital foramen. Tessier 7 is macrostomia. Tessier 8 is the ‘equator’. Tessier 0,14 is nasofrontal dysplasia. 14 12 13 9 10 11 8 7 6 7b 4 3 10 9 8 1 5 7 23 6 7 4 5 321 0 13 12 11 7 30 0 7 1 2 3 3 4 5 6 6 4 5 7 7 5 7 0 11 12 10 14 0 13 12 1 2 9 3 8 4 5 3 4 5 6 Source: Tessier (1976). Reproduced with permission of Elsevier. 6 12 3 4 The Head and Neck 141 Principles of surgery 1 Functions: oral competence, speech and eyelid reconstruction. 2 Separation of cavities: oral, nasal and orbital. 3 Cosmesis. ∘ The skeleton can be reconstructed by: – Removing abnormal elements. – Transposing skeletal components (including distraction osteogenesis). – Bone grafting skeletal defects. – Alloplastic implants. ∘ Musculature is reattached to the skeleton in its correct anatomical position. – Sphincters should be recreated where possible. ∘ Soft tissues can be reconstructed with: – Local, regional or distant flaps with or without prior tissue expansion. – Use of Z-plasty to redirect scars. ∘ Reconstruction is facilitated by a wide surgical exposure. Hypertelorism • An increase in the distance between the bony orbits. • May be seen in the context of facial clefts. • The intervening ethmoid sinuses (interorbital space) are overexpanded. ∘ In practice, it is always a congenital condition. ∘ Trauma cannot cause true widening of the nasal–orbital walls without creating large midline defects. • Hypertelorism may prevent development of binocular vision. ∘ It is also a significant cosmetic problem. • Telecanthus is an increase in the intercanthal distance (ICD). ∘ In telecanthus, the distance between the bony orbits may be normal. • Pseudotelecanthus is the illusion of telecanthus caused by a flat nasal bridge or prominent epicanthal folds. Classification • Tessier graded hypertelorism in adults according to interorbital distance (IOD): ∘ First degree: IOD 30–34 mm ∘ Second degree: IOD >34 mm ∘ Third degree: IOD >40 mm • A normal adult IOD is 22–30 mm. • IOD is measured on a posteroanterior (PA) X-ray or computed tomography (CT) scan as the interdacryon distance. ∘ The dacryon is the point of union of lacrimal, frontal and maxillary bones. Causes • Hypertelorism is associated with numerous conditions: ∘ Median and paramedian facial clefts ∘ Sincipital encephaloceles ∘ Midline tumours. 142 ∘ Chapter 3 Craniofacial syndromes: – Apert’s – Crouzon’s – Craniofrontonasal dysplasia. Surgical management • CT is essential for preoperative planning. • Ophthalmological assessment of visual acuity, amblyopia or extraocular dysfunction is required. • The orbits can be repositioned without disturbing the optic nerve because the optic foramina are not displaced. • Tessier gives these basic principles: ∘ The 360∘ orbit must be mobilised to allow adequate translocation. ∘ The ‘functional orbit’ posterior to the equator of the globe must be mobilised. ∘ A combined craniofacial approach protects the brain. – The roof of the orbit is also the floor of the anterior cranial fossa. Box osteotomy • Used for patients with hypertelorism and normal midface width. • Through a coronal approach, osteotomies are made around each orbit. • Nasal bones and ethmoid sinus are removed, and the orbits moved medially towards each other. ∘ Alternatively, two paramedian segments are resected, which preserves the nasofrontal junction and cribriform plate. • Rigid fixation is achieved with plates and screws. Facial bipartition • This procedure is well-suited to treat an inverted V deformity of maxillary occlusion. • Orbital osteotomies leave the floor in continuity with the maxilla. • Osteotomy through the midincisor line allows medial rotation/transposition. • An occlusal splint ensures proper positioning of the maxilla. • Rigid fixation, augmented with bone graft, holds the reduction. Medial canthopexy • Osteotomies usually result in detachment of the medial canthal ligament. • If not reattached, canthal drift gives the appearance of recurrence of the hypertelorism. Encephaloceles • Caused by herniation of brain or its lining through a skull defect. ∘ Frontal skeletal defects can result from Tessier clefts 10, 13 and 14. • Clinically, they are soft, pulsatile, compressible masses. • They may transilluminate and have a positive Furstenberg’s sign. ∘ This is pulsation or expansion of the mass with crying or straining. • Encephaloceles are classified by their composition into: ∘ Meningoceles – contain meninges ∘ Meningoencephaloceles – contain meninges and brain The Head and Neck 143 ∘ ∘ Cystoceles – contain meninges, brain and a portion of ventricle Myeloceles – contain a portion of spinal cord. • Differential diagnosis includes teratomas, gliomas and dermoids. • Principles of treatment include: ∘ Surgical planning aided by ultrasound (US), X-ray, CT and magnetic resonance imaging (MRI). ∘ Multidisciplinary surgical team for a combined intra- and extra-cranial approach. ∘ Incision of the sac. ∘ Amputation of excess tissue to the level of the surrounding skull. ∘ Dural closure. ∘ Bony reconstruction. ∘ Skin closure. • The remaining intracranial brain tissue should be imaged for abnormalities. Synostosis • Premature fusion of one or more sutures in the cranial vault or skull base. • Occurs approximately once in every 2500 live births. • May occur: ∘ As an isolated abnormality or ∘ As part of a syndrome. • Nonsyndromal synostosis accounts for 90% of cases. • Most synostosis syndromes are autosomal dominant. ∘ The often-cited exception – Carpenter’s syndrome – is autosomal recessive. • Genetic mutations can be identified in: ∘ 70% of patients with Crouzon’s, Pfeiffer’s or Saethre–Chotzen syndrome. ∘ Almost 100% of patients with Apert’s syndrome. • Craniosynostosis begins during pregnancy or the first year of life. • Usually complete by 3 years. Aetiology • Three theories have been proposed: 1 Virchow suggested a primary sutural abnormality. 2 McCarthy suggested a dural abnormality. 3 Moss suggested abnormality in the skull base. • Many synostotic syndromes may be caused by gene mutations in MSX2, TWIST and fibroblast growth factor receptors 1, 2 and 3 (FGFRs). • Many craniosynostosis syndromes have associated limb abnormalities. ∘ Craniofacial and limb development may share common molecular pathways. Classification • Synostosis is classified according to: ∘ The location of the affected suture or sutures. ∘ The resultant head shape. • The sagittal suture is the most common single suture synostosis (40–60%). • It has a male preponderance of 4:1. • Virchow’s law states that skull growth occurs parallel to a synostosed suture. 144 Chapter 3 • Each pattern of fusion therefore results in a characteristic skull shape: ∘ Sagittal suture: an elongated keel-shaped skull (scaphocephaly or dolichocephaly). ∘ One coronal suture: a twisted skull (plagiocephaly). ∘ Both coronal sutures: a short skull anteroposteriorly (AP) (brachycephaly). – Compensatory growth may occur upwards (turricephaly, oxycephaly or acrocephaly). ∘ Metopic suture: a triangular-shaped skull (trigonocephaly). ∘ One lambdoid suture: a twisted skull (posterior plagiocephaly). ∘ Both lambdoid sutures: a short skull (brachycephaly). ∘ Synostosis of multiple sutures leads to a cloverleaf-shaped skull (Kleeblattschädel or triphyllocephaly). • In Greek, dolichos is long; scaphos is boat; plagios is oblique; brachys is short; acros is high; oxys is sharp; trigonos is triangular; triphyllos is trefoil or three leaves. • In Latin, turris is tall. • In German, Kleeblattschädel is cloverleaf skull. Clinical features • The most striking feature is abnormal skull shape. • Because the face is attached to the cranial base, synostosis may limit or distort growth of the face and affect occlusal plane symmetry. ∘ Midface hypoplasia can lead to obstructive sleep apnoea, requiring continuous positive airways pressure (CPAP) therapy. • Bicoronal synostosis may result in recession of the fronto-orbital rim. ∘ Can lead to exorbitism and exposure keratitis. – Exorbitism is protrusion of the eyeball due to decreased volume of the bony orbit. – This is different from exophthalmos, which is protrusion of the eyeball due to an increased volume of orbital contents in a normal bony orbit. • Patients may show signs and symptoms of raised intracranial pressure (ICP), including: ∘ Irritability/headaches ∘ Vomiting ∘ Tense fontanelles ∘ Papilloedema ∘ Developmental delay ∘ Seizures. • Long-term problems of untreated raised ICP include: ∘ Blindness ∘ Intellectual disability. • Incidence of raised ICP increases proportionately with the number of involved sutures: ∘ Approximately 14% with single suture synostosis. ∘ Approximately 47% with multiple suture synostosis. • Normal ICP values in children are arbitrarily set: ∘ <10 mmHg is considered normal. ∘ 10–15 mmHg is considered borderline. ∘ >15 mmHg is considered high. The Head and Neck 145 • Plotting head circumference on a growth chart can help differentiate synostosis from primary microcephaly or hydrocephalus. • The cranial index (CI) is the ratio of maximum cranial width to maximum cranial length. ∘ Children with isolated sagittal synostosis typically have CIs of 60–67%. ∘ Children with normal head shape typically have CIs of 76–78%. ∘ Children with isolated coronal synostosis typically have CIs of 84–91%. • CI is not a diagnostic measure but helps quantify the difference between pre- and postoperative head shape. Radiological features • Include primary changes in the suture and secondary changes due to abnormal skull growth. • Primary changes include: 1 Loss of suture lucency 2 Loss of sutural interdigitations 3 Sclerosis of the suture 4 Raising (lipping) of the suture. • Secondary changes include: 1 Abnormal skull shape 2 Harlequin appearance of the lateral orbit on AP films. – Caused by superior displacement of the lesser wing of sphenoid. 3 Copper-beaten appearance of the skull (a sign of raised ICP). 4 Widening of the adjacent sutures in compensation. • CT allows direct visualisation of each suture. • MRI is not used routinely. ∘ In syndromic cases, it can rule out cerebellar tonsillar herniation (Arnold–Chiari malformation), which may limit compensatory diversion of cerebrospinal fluid (CSF) in raised ICP. Positional plagiocephaly • True plagiocephaly is caused by unilateral synostosis of the coronal or lambdoid sutures. • Positional plagiocephaly is distortion of the skull due to external pressure. • Incidence of positional plagiocephaly has increased in recent years due to the ‘Back to Sleep’ campaign, which recommends nursing babies supine to reduce the risk of cot death. • Positional plagiocephaly should be managed nonoperatively, as it is usually self-correcting: ∘ ‘Active repositioning’ into the prone position during waking hours. ∘ Special orthotic helmets are commercially available to help remodel the skull. ∘ Physiotherapy may be required to treat an underlying cause, such as torticollis. • Clinical features that differentiate positional from true plagiocephaly include: ∘ Skull shape – The skull is rhomboid shaped in positional plagiocephaly. – The occiput is flattened by external pressure, which pushes the ear and forehead forward on that side. 146 ∘ ∘ ∘ Chapter 3 – In true plagiocephaly, one side of the skull does not grow adequately in an AP direction due to synostosis. • This produces a triangular-shaped skull. • The base of the triangle lies on the unaffected side. • The apex of the triangle lies on the affected side, as if pinched at the site of synostosis. Ear position – In true plagiocephaly, the distance between the lateral orbit and the ear is asymmetrical. Brow shape – The brow has an ipsilateral prominence in positional plagiocephaly. – It has a contralateral prominence in true plagiocephaly. Cheek position – The ipsilateral cheek is prominent in positional plagiocephaly. Syndromal synostosis • Synostosis is a feature of over 100 syndromes. • The more common syndromes share many features: ∘ Midface hypoplasia ∘ Skull base growth abnormalities ∘ Abnormal facies ∘ Limb abnormalities. Apert’s syndrome • Occurs once in 160,000 live births. • Most cases are sporadic but can be autosomal dominant. • Clinical features: ∘ Bicoronal synostosis ∘ Exorbitism with hypertelorism ∘ Downslanting palpebral fissures ∘ Midface hypoplasia ∘ Small, beaked nose ∘ Class III malocclusion ∘ CP in 20% of cases ∘ Complex syndactyly of both hands and feet. • The hand deformity is classified as: ∘ Type I: little finger and thumb are separate. ∘ Type II: only the thumb is separate. ∘ Type III: all fingers are fused and share a common nail. • There may be nonprogressive ventriculomegaly, but hydrocephalus is uncommon. • Some have delayed mental development, but many develop normal intelligence. • Conductive hearing loss is common. • Cardiac and genitourinary abnormalities found in up to 10% of cases. The Head and Neck 147 Crouzon’s syndrome • Affects one in 25,000 live births. • Most are autosomal dominant but can occur sporadically. • Clinical features: ∘ Bicoronal synostosis, although other sutures may be involved ∘ Midface hypoplasia with significant exorbitism ∘ Normal hands ∘ High palatal arch; occasional CP ∘ Class III malocclusion ∘ Conductive hearing loss. • Progressive hydrocephalus, often associated with chronic tonsillar herniation. • In the absence of raised ICP, developmental delay is rare. Saethre–Chotzen syndrome • Estimated to affect one in 50,000 live births. • Caused by mutations in the TWIST gene (autosomal dominant). • Clinical features: ∘ Bicoronal synostosis ∘ Low-set hair line ∘ Eyelid ptosis ∘ Small, posteriorly displaced ears with prominent crura ∘ Partial syndactyly of the second and third digits is often seen. • Intelligence is usually normal, but some have mild impairment. Pfeiffer’s syndrome • Rare; inherited as an autosomal dominant trait. • Craniofacial appearance is similar to that of Apert’s. • A severe form of Pfeiffer’s is characterised by Kleeblattschädel deformity and profound CNS abnormalities. • Otherwise, intelligence is usually normal. • Hallmark feature is broad great toes and thumbs. Muenke’s syndrome • Discovered in 1996; also known as FGFR3-associated coronal synostosis. • Differs from other syndromic synostoses because it is defined by a genetic test (Pro250Arg mutation) rather than a constellation of symptoms and signs. • Affects one in 30,000 and inherited as an autosomal dominant trait. • Coronal sutures are specifically involved; appearances are otherwise largely normal. • Hearing loss (30%) and learning difficulties (10%) may occur. • Reoperation is required more often than with other syndromic synostoses. Carpenter’s syndrome • Very rare autosomal recessive condition. • Various sutures may be involved, commonly sagittal and coronal. 148 • • • • Chapter 3 Intelligence is usually impaired. Congenital cardiac abnormalities seen in 1∕3 of cases. Obesity is typical. Clinical features: ∘ Partial syndactyly of the fingers. ∘ Preaxial polydactyly of the feet. Treatment • Surgery is extensive and potentially risky, associated with significant blood loss. • Regarded as safe if performed by specialist teams in established centres. • Main aims of surgery: ∘ Protect the airway and corneas ∘ Prevent progressive deformity ∘ Correct established deformity ∘ Reduce risks to function from raised ICP. • Advantages of operating in infancy include: ∘ Harnessing the most ‘brain push’ to remodel the calvarium during infancy. ∘ Postsurgical defects ossify more completely before 9–10 months. ∘ Infantile calvarium is more malleable. • However, operating too early can lead to excessive blood loss and difficulties with fixation because the bone is too soft. • Shunting procedures to treat progressive hydrocephalus are usually done prior to bony remodelling. ∘ Were both procedures carried out simultaneously, shunting would reduce brain size while vault remodelling would increase skull size. ∘ The resulting dead space would allow haematoma to collect. • Surgical techniques include: Sagittal strip craniectomy • A longitudinal strip of bone over the suture is excised. Fronto-orbital advancement and anterior cranial vault reconstruction • The fronto-orbital bar is advanced and held with miniplates. ∘ This increases the AP dimension of the skull. ∘ Also deepens the upper orbits, improving exorbitism. • The remaining frontal bone is sectioned and replaced in the desired shape. Posterior cranial vault reconstruction • Distraction osteogenesis is being used more frequently, given the higher incidence of severe bleeding with posterior vault remodelling. Le Fort III osteotomy • Performed to correct midface retrusion encountered in syndromal synostosis. • May be performed early, aiming to become independent of tracheostomy or ameliorate severe obstructive sleep apnoea. The Head and Neck 149 Monobloc advancement • Advances the fronto-orbital and Le Fort III segments as one block. • Associated with higher infection rates and greater blood loss, likely due to communication between cranial and nasal cavities. Le Fort I osteotomy • Addresses class III malocclusion and anterior open bite, commonly seen with midface hypoplasia. • Planned to coincide with completion of orthodontic treatment, at the time of skeletal maturity. Skeletal distraction • Many skeletal manipulations are now done by distraction, including: ∘ Le Fort I ∘ Posterior cranial vault ∘ Le Fort III ∘ Monobloc ∘ Mandible. • Osteotomies are made as usual. • A distraction device is fitted either internally or externally. • As the bone is distracted, the soft tissues are gradually stretched over several weeks. ∘ Greater advancement can be achieved with distraction than by single-stage advancement. • Once the desired advancement is achieved, further surgery may be required to stabilise the bones with plates and screws. ∘ If not, a prolonged period of consolidation is required with the distractor in place. Post-operative care • Monitoring of haemodynamic stability and conscious level on a paediatric intensive care unit is required for 24–48 hours. • A significant amount of swelling is expected. • Pyrexia of 38 ∘ C for the first 72 hours is not unusual. Complications • Overall mortality reported as 1–2% in specialist units. • Low risk of infection, dehiscence, meningitis, dural tears with CSF leak, air embolus, cerebral oedema and life-threatening bleeding. • Coagulopathy is most commonly precipitated by massive blood transfusion and low body temperature. • There may be persisting asymmetry, contour irregularities or incomplete ossification. Atrophy–hypoplasia • This group includes: ∘ Hemifacial microsomia ∘ Treacher Collins syndrome 150 Chapter 3 ∘ ∘ ∘ ∘ ∘ Nager’s syndrome Binder’s syndrome PRS Hemifacial atrophy Radiation-induced atrophy–hypoplasia. • Many of these conditions could be classified as clefts due to the predictable lines of hypoplasia seen in some Tessier clefts. Hemifacial microsomia • Congenital condition with a variable phenotype, characterised by underdevelopment of one side of the face. Also known as: ∘ First and second branchial arch syndrome. ∘ Otomandibular dysostosis. • Correlates with a Tessier 7 cleft. • Hemifacial microsomia is relatively common, affecting one in 4000 live births. • Unlike Treacher Collins syndrome, it is not usually inherited and is typically asymmetrical. • It may arise due to haemorrhage from an abnormal stapedial artery. • Clinical features: ∘ Underdevelopment of the external and middle ear. ∘ Underdevelopment of the mandible, zygoma, maxilla, temporal bone, facial muscles, muscles of mastication, palatal muscles, tongue and parotid gland. ∘ Macrostomia, a first branchial cleft sinus and possible cranial nerve involvement. • Goldenhar syndrome is a variant of hemifacial microsomia but is typically bilateral, associated with epibulbar dermoids and vertebral abnormalities. Classification • The following classifications of hemifacial microsomia have been described: • OMENS classification ∘ This classifies deformities of the Orbits, Mandible, Ear, Facial Nerve and Soft tissue. • Pruzansky classification of the mandible: ∘ Type I: mild ramus hypoplasia, the body is minimally affected. ∘ Type IIa: ramus and condyle hypoplasia, but the glenoid–condyle relationship is maintained. ∘ Type IIb: as for type IIa but with a nonarticulating temporomandibular joint (TMJ). ∘ Type III: the ramus is very thin or absent with no evidence of a TMJ. – Mulliken and Kaban subdivided Pruzansky type II as shown. • Meurman classification of the ear: ∘ Grade I: small, malformed auricle, but all components present. ∘ Grade II: vertical remnant of cartilage and skin; atresia of the external meatus. ∘ Grade III: total or near-total absence of the auricle. • SAT classification ∘ Proposed by David, it is analogous to the TNM system used in cancer staging. The Head and Neck ∘ 151 It grades the Skeletal, Auricular and soft Tissue anomalies and suggests a treatment plan. Treatment • Should be individualised to the patient. • Abnormalities in other organ systems should be sought. • The following is a general guide: Before 2 years • Remove any auricular appendages. • Correct macrostomia with a commissuroplasty. • Fit hearing aids. • Occasional involvement of the fronto-orbital region may require fronto-orbital advancement. Between 2 and 6 years • Distraction of the mandibular ramus. • Pruzansky III deformities may require formal reconstruction of the mandibular ramus. ∘ This is usually performed with a costochondral rib graft. Between 6 and 14 years • Orthodontic treatment. • Ear reconstruction. • Soft tissue augmentation: ∘ Free tissue transfer ∘ Fat grafting. After 14 years • Augmentation of deficient areas of the facial skeleton. ∘ Can be done using bone grafts or alloplastic implants, e.g. Medpor®. • Orthognathic surgery (OGS). Treacher Collins syndrome • Also known as: ∘ Franceschetti syndrome. ∘ Mandibulofacial dysostosis. ∘ Tessier 6,7,8 cleft. • Autosomal dominant with variable expressivity. • Affects between one in 25,000 and one in 50,000 live births; equal sex distribution. Clinical features • Bilateral symmetrical abnormalities of the first and second branchial arches. • Characteristic convex facial profile. ∘ Prominent nasal dorsum and retrusive lower jaw and chin. 152 Chapter 3 • Average or above-average intelligence is the norm. • Typically, abnormalities are present in the following sites: Eyes • Part of the lateral canthus and lower eyelid may be absent (coloboma). • Eyelashes are often absent medially. • Atrophic tarsal plate. • Medially displaced lateral canthus. • Absent lacrimal apparatus. • Antimongoloid slant of the palpebral fissure. • Hypoplastic lateral orbits. Nose • Moderately wide bridge with mid-dorsal hump. • Drooped tip that lacks projection. Cheek • The zygoma may be hypoplastic, clefted through the arch or absent. • A depression may run between the corner of the mouth and angle of the mandible, along the line of a Tessier 7 cleft. Palate • CP, with or without CL, occurs in 30% of cases. • There may be associated choanal atresia. • If not, the palate is usually high-arched. Maxilla and mandible • The ramus of the mandible is often short. • TMJ and muscles of mastication may be hypoplastic or absent. • Class II malocclusion with anterior open bite. Ear • May be small (microtia) or buried under the skin (cryptotia). • External meatus may be hypoplastic. • Middle ear deformities include missing ossicles or cavities. Cranium • Reduced cranial base angle (basilar kyphosis). • Although synostosis is not a feature, the skull may have abnormally short AP length and bitemporal width. Treatment Airway • Patients often have difficulty maintaining their airway due to maxillary and mandibular hypoplasia. ∘ Tracheostomy may be required. The Head and Neck 153 • Nursing them in a prone position can help improve their oxygen saturation. • Increased risk of airway obstruction following CP repair. Feeding • Factors affecting the airway can also affect swallowing and feeding. • Failure to thrive requires supplemental tube feeding. Zygoma and orbit • Calvarial bone graft can be used to augment the orbital floor and zygoma. • Lateral canthopexy is done through the same bicoronal incision. • Usually performed when the child is >7 years, when bony development in that region is almost complete. Mandible • Mandibular deformity may be corrected with: ∘ Rib grafts ∘ Mandibular advancement ∘ Bimaxillary procedures ∘ Le Fort I osteotomy and orthodontic treatment ∘ Distraction ∘ Genioplasty ∘ TMJ reconstruction with costochondral graft (Pruzansky III). • Usually performed at early skeletal maturity, between 13 and 16 years. Ear • Reconstruction of the external ear may be required. • Middle ear surgery is postponed until after auricular reconstruction, to preserve soft tissues. • Hearing deficits can be improved with hearing aids. Nose • Rhinoplasty involves: ∘ Open approach ∘ Osteotomies ∘ Dorsal hump reduction ∘ Cephalic trim of the lower lateral cartilages ∘ Columella strut to improve tip projection. • This is done following any OGS. Nager’s syndrome • Also known as acrofacial dysostosis. • Rare; inherited as an autosomal recessive trait. • Craniofacial features are similar to Treacher Collins syndrome. • CP is almost universal. • There is associated thumb and radial hypoplasia. • Intelligence is usually impaired. 154 Chapter 3 Binder’s syndrome • Also known as maxillonasal dysplasia. • May be inherited as an autosomal recessive trait. • Clinical features: ∘ Short nose with flat bridge and short columella ∘ Absent frontonasal angle ∘ Absent anterior nasal spine ∘ Perialar flattening ∘ Convex upper lip ∘ Tendency to class III malocclusion. Pierre Robin sequence (PRS) • Affects approximately one in 8500 live births and consists of: ∘ Micrognathia ∘ Glossoptosis ∘ CP. • Due to a small jaw, the tongue occupies a greater proportion of the oropharynx. • Severe respiratory obstruction can result from the tongue falling backwards (glossoptosis). • The combined effort of feeding and maintaining the airway is tiring. ∘ This leads to faltering growth or failure to thrive. • Most babies have outgrown these difficulties by 6 months, due to mandibular growth and improved neuromuscular control of the tongue. • Reports suggest underlying genetic mutations in SOX9 and KCNJ2. Treatment • Immediate life-saving airway management involves turning the newborn prone to relieve glossoptosis. • If unsuccessful, a nasopharyngeal airway (NPA) can be inserted to bypass the obstruction caused by the tongue. • PRS has been classified by severity by the Cleft service at Birmingham Children’s Hospital, UK. • This classification is also used to guide treatment: ∘ Grade 1: Nursed side-to-side only. ∘ Grade 2: Requires nasogastric (NG) feeding and nursed side-to-side. ∘ Grade 3: Requires NPA, NG feeding and nursed side-to-side. • Once stabilised and gaining weight, all PRS babies are discharged with an oxygen saturation monitor. • A cleft specialist nurse closely monitors weight gain. • Parents and other carers are trained to manage NG feeds and the NPA. ∘ Also trained in Paediatric Basic Life Support prior to discharge. • Birmingham Children’s Hospital successfully treats all PRS babies this way. • Other more invasive treatments include: ∘ Glossopexy (tongue–lip adhesion) ∘ Tracheostomy The Head and Neck 155 ∘ ∘ Subperiosteal release of the floor of the mouth Distraction osteogenesis of the mandible – Distraction osteogenesis carries a low but quantifiable mortality rate. • Some surgeons maintain that a proportion of severely affected PRS babies require surgical intervention, but that view is controversial. • PRS may present with other syndromes and anomalies. ∘ All PRS babies should be screened for Stickler’s syndrome. – There is a risk of retinal detachment, preventable by early intervention. Progressive hemifacial atrophy (PHA) • Acquired condition also known as Parry–Romberg syndrome. • Usually unilateral; 5% of cases are bilateral. • Occurs sporadically and not associated with a family history. • Aetiology is unknown; may be due to viral infection, trigeminal peripheral neuritis or an abnormality in the cervical sympathetic nervous system. • Presents similar to linear scleroderma in early stages. Clinical features • Characterised by gradual wasting of one side of the face and forehead. • Usually starts between 5 years and late teens. • Female to male ratio is 1.5:1. • Involves skin, soft tissue and bone. • Muscle involvement can also include atrophy of the tongue and palate. • Typically progresses within the dermatome of one or more divisions of the trigeminal nerve. • Wasting continues for a number of years before gradually stopping. • The result is permanent tissue deficiency on one side of the face. • The following may be seen: ∘ Localised atrophy of the skin with pigment changes ∘ Change of hair colour or alopecia ∘ Change of iris colour and enophthalmos ∘ A sharp depression on the forehead, occasionally extending into the hairline – This early sign is known as ‘coup de sabre’ ∘ Atrophy of cheek bone and soft tissue ∘ Malocclusion. Treatment • Generally, no treatment is performed while the condition is active and progressive. • Short-term improvements may be achieved with injectable fillers. • Reconstruction is performed once the condition has been stable for about 12 months. ∘ This is judged by serial photographs. • Reconstructive options include: ∘ Fat and dermofat grafts ∘ Cartilage grafts ∘ Le Fort I osteotomy 156 ∘ ∘ ∘ ∘ ∘ Chapter 3 Genioplasty Alloplastic augmentation Temporoparietal fascia and temporalis muscle transfers Free tissue transfer. Adipofascial flaps are preferred over muscle flaps due to the atrophy of muscle over time. Radiation-induced atrophy–hypoplasia • High dose radiation is used to treat some childhood tumours. • Deformity may arise by the following mechanisms: ∘ Impaired growth as the sphenoid ‘locks in’ the upper face. ∘ The frontal, ethmoid and maxillary sinuses fail to expand. • Reconstruction usually involves a combined craniofacial approach: ∘ Craniotomy to reposition the skull base, orbit and maxilla ∘ Orbital expansion and mandibular lengthening ∘ Bone grafts (inlay rather than onlay) ∘ Free tissue transfer to augment the soft tissues. Neoplasia–hyperplasia Fibrous dysplasia • Rare, non-neoplastic benign bone disease. • Lesions are osseous rather than fibrous, characterised by abnormal proliferation of boneforming mesenchyme. ∘ Bone maturation stalls at the woven bone stage. • Usually presents as an enlarging mass in the maxilla or mandible. • Mass effect can cause cranial nerve compression, proptosis and malocclusion. • Malignant transformation occurs in 0.5% of patients. • The condition is usually progressive until about 30 years. • Diagnosis is confirmed on bone biopsy. Classification 1 Monostotic, with single bone involvement. ∘ Craniofacially, it usually affects frontal bone, sphenoid or maxilla. ∘ Can also affect ribs, femur or tibia. 2 Polyostotic, with multiple bone involvement. ∘ Approximately 3% have the triad of McCune–Albright syndrome: – Polyostotic fibrous dysplasia – Precocious puberty – Café-au-lait macules. • Hyperthyroidism and tumours of the pituitary gland may also be found. • Cherubism is a rare autosomal dominant condition, also known as familial fibrous dysplasia. ∘ Characterised by multiple areas of fibrous dysplasia within the mandible and maxilla. ∘ Self-limiting and regresses spontaneously, leaving no deformity. The Head and Neck 157 Treatment • Early intervention is required when function is at risk: ∘ Optic nerve compression or other nerve palsies ∘ Diplopia ∘ Malocclusion. • Surgery involves resection of the abnormal areas. • The resultant defects can be reconstructed with calvarial bone grafts or alloplastic implants. • Free tissue transfer is used to fill postresection dead space. • Some cases have responded to bisphosphonate therapy. Neurofibromatosis • A group of genetic disorders that predispose to development of Schwann cell tumours. • Inherited as an autosomal dominant trait with variable penetrance. • 50% of new cases arise from spontaneous mutations with no family history. Classification • Many types have been described; only two forms are commonly encountered: Neurofibromatosis type 1 (NF1) • Also known as von Recklinghausen’s disease. • The most common type (90%), affecting one in 3000 births. • The mutated gene is on chromosome 17. • Two of the following clinical features are required for diagnosis: ∘ Six or more café-au-lait macules (>0.5 cm in children; >1.5 cm in adults) ∘ Two or more neurofibromas or one plexiform neurofibroma ∘ Axillary or inguinal freckling ∘ Optic glioma ∘ Two or more Lisch nodules (hamartomas of the iris) ∘ A distinctive osseous lesion with cortical thinning or dysplasia ∘ A first-degree relative with NF1. • NF1 is associated with orthopaedic complications, including: ∘ Scoliosis or kyphosis of the spine ∘ Congenital bowing and pseudarthrosis of the tibia and forearm. Neurofibromatosis type 2 (NF2) • Also known as central neurofibromatosis. • Affects approximately one in 25,000 live births. • The mutated gene is on chromosome 22. • Characterised by bilateral vestibular schwannomas. • Other abnormalities include: ∘ Intracranial meningiomas ∘ Spinal tumours (usually schwannomas or meningiomas) ∘ Peripheral nerve schwannomas ∘ Ocular abnormalities (posterior subcapsular lenticular opacities). 158 Chapter 3 Malignancy • Lifetime risk of malignant transformation is <10%. • Malignant peripheral nerve sheath tumours (MPNST) arise from Schwann cells. ∘ Usually occur in plexiform neurofibromas. • Pain and rapid growth are indicators of malignant degeneration. ∘ Positron emission tomography (PET) scanning can help localise the malignancy. • Metastases are common. • An aggressive surgical attempt at total excision is undertaken. • 5-year survival following MPNST is approximately 16–52%. Treatment • Treatment of plexiform neurofibromas requires a multidisciplinary team (MDT) approach. • Trials are underway looking at imatinib for treatment of plexiform neurofibromas. • However, surgery is currently the mainstay of treatment. • The following should be considered: ∘ Timing and extent of surgery ∘ Strategies to deal with bleeding refractory to conventional electrocautery: – Hypotensive anaesthesia, invasive monitoring and cell salvage – Some advocate packing the wounds open with direct compression. • Delayed closure then takes place after 48 hours. • There is a balance between an acceptable aesthetic outcome and preserving function. ∘ The limits of surgery should be discussed with the patient. • Surgery addresses the deformity only; recurrence is usual. • Improvements are temporary because skin involved with neurofibroma lacks elasticity. • Specific craniofacial problems associated with NF1 include: Orbitopalpebral neurofibromas • Associated with dysplasia of the sphenoid wing. ∘ Allows the temporal lobe to herniate into the orbit. • The bony orbit is enlarged, with pulsatile exophthalmos. • If vision is preserved in the affected eye, the neurofibroma is debulked. • The orbit can be approached through: ∘ The upper eyelid for mild lesions ∘ A bicoronal skin incision with osteotomy into the lateral orbit ∘ A combined craniofacial approach with frontal craniotomy. • The sphenoid wing is reconstructed using split rib or calvarial bone graft. • If vision is impaired, orbital exenteration is performed. ∘ The eyelid is used for skin cover to allow the orbit to take a prosthesis. Plexiform neurofibromas of the facial soft tissues • Cause distortion of the facial soft tissues and skeleton. ∘ Deformities can lead to visual loss. • Bony defects are tackled first, with correction of the occlusal plane. • Soft tissues are reconstructed with free tissue transfer or dermal-fascial-fat grafts. The Head and Neck 159 • Tissue redundancy is addressed through a facelift incision or Weber–Ferguson approach. • Techniques to minimise recurrence of soft tissue ptosis include: ∘ Anchoring tissue to bone ∘ Fascia lata slings. Unclassified craniofacial abnormalities • These include organ-specific abnormalities: ∘ Anophthalmia ∘ Choanal atresia ∘ Anotia. Congenital dermoid cysts • Commonly located in the superolateral orbit, orbital rim and forehead. • Represent displacement of dermal and epidermal cells into embryonic lines of fusion. ∘ They differ from inclusion cysts by the presence of dermis and skin adnexa. • Complete surgical excision is the only effective treatment. • Can be excised through a supratarsal incision on the upper eyelid. ∘ Dissection proceeds through the orbicularis oculi onto the cyst. ∘ Often located deep to periosteum. Nasal dermoid cysts • Approximately 10% of dermoids are located on the nose. ∘ Have a different origin to other dermoids and warrant investigation. Embryology • Frontal and nasal bones are separated by a small fontanelle – the fonticulus nasofrontalis. • A prenasal space exists between the skull base and nasal tip. • Dura extends through the fonticulus into the prenasal space, where it contacts skin. • With facial growth, the dura separates from the skin and recedes. ∘ At this time, the fonticulus nasofrontalis and foramen cecum fuse, forming the cribriform plate. • Nasal dermoids and sinuses are formed when the dura fails to separate from skin. ∘ As the dura retracts intracranially, it pulls ectodermal tissue with it. • Nasal or midline dermoids should be imaged to rule out intracranial extension. ∘ CT may show a bifid crista galli and patent foramen cecum. ∘ MRI further demonstrates the extent of intracranial involvement. Treatment • A combined craniofacial approach with a neurosurgeon. • The entire cyst can sometimes be removed through a frontal craniotomy. • Alternatively, it can be approached by direct incision around the cyst or open rhinoplasty. ∘ The stalk is traced superiorly, between the cartilaginous septum and nasal bones. ∘ If the stalk is not excised, craniotomy is required to ensure complete removal. ∘ Incomplete excision can lead to infection and osteomyelitis. 160 Chapter 3 Cleft lip; cleft lip and palate Cleft lip (CL) • CL is a congenital abnormality of the primary palate. • The primary palate lies anterior to the incisive foramen and consists of: ∘ The lip ∘ The alveolus ∘ The hard palate anterior to the incisive foramen. Cleft palate (CP) • CP is a congenital abnormality of the secondary palate. • The secondary palate lies posterior to the incisive foramen and consists of: ∘ The hard palate posterior to the incisive foramen ∘ The soft palate. • Isolated CP is embryologically and aetiologically distinct from CL and CL&P. Cleft lip and cleft palate • Both CL and CP may be: ∘ Complete or incomplete ∘ Unilateral or bilateral. • Unilateral CP occurs when the vomer remains attached to one palatal shelf. • Bilateral CP occurs when the vomer is attached to neither palatal shelf. • In isolated CP, the vomer tends to be high and hypoplastic. Epidemiology • Incidence of CL&P varies according to the study population. ∘ In the United Kingdom, CL, CL&P and CP occur once in 700 live births. ∘ In Caucasians, CL ± CP occur once in 1000 live births. ∘ In Asia, the incidence is higher: once in 500 live births. ∘ In Africa, the incidence is lower: once in 2500 live births. • Combined CL&P is most common, seen in 50% of cases. ∘ Isolated CP occurs in 30% of cases. ∘ Isolated CL occurs in 20% of cases. • The ratio of left:right:bilateral CL is 6:3:1. CL and CL&P • Twice as common in males. • Has a familial association. • The relative risk of a child having CL or CL&P is: ∘ 0.1% if there is no history of CL or CL&P in the family ∘ 4% if there is one affected sibling The Head and Neck 161 ∘ ∘ ∘ • • • • • 7% if there is one affected parent 9% if there are two affected siblings 17% if one parent and one sibling are affected. Only 10% of CL and CL&P cases are associated with other abnormalities. Van der Woude syndrome is one of the few syndromes associated with CL. ∘ 1–2% of CL and CL&P patients are affected. ∘ It has the following characteristics: – Autosomal dominance – Lower lip pits – Absence of second premolar teeth. Environmental teratogens associated with CL and CL&P include: ∘ Intrauterine exposure to phenytoin (10-fold increased incidence) ∘ Maternal smoking (twofold increased incidence) ∘ Maternal diabetes ∘ Excessive maternal alcohol consumption ∘ Other anticonvulsants ∘ Retinoic acid and its derivatives. These are associated, not causal, factors. Some studies show that maternal folic acid supplementation produces a lower rate of cleft deformities than predicted. Isolated CP • Twice as common in females. • Fairly consistent worldwide incidence: once in 2000 births. • Occurs in association with other abnormalities or syndromes in up to 70% of cases. • Nonsyndromal CP may be associated with the environmental teratogens previously mentioned. Mechanism • CL is thought to be caused by either: ∘ Failure of fusion between the medial nasal process and maxillary process or ∘ Failure of mesodermal penetration into the layer between ectoderm and endoderm. – This leads to breakdown of the processes after they have initially fused. Anatomy • Complete unilateral CL deformity is characterised by: 1 Discontinuity in the skin and soft tissue of the upper lip. 2 Vertical and transverse soft tissue deficiency on the cleft side. 3 Abnormal attachment of lip muscles into the alar base and nasal spine. 4 Outwardly rotated and prominent premaxilla. 5 Retropositioned and hypoplastic lateral maxillary element. 162 Chapter 3 6 Cleft in the alveolus, usually found at the site of future canine tooth eruption. 7 Defect in the hard palate anterior to the incisive foramen. 8 Nasal deformity. Incomplete CL • CL is incomplete when the cleft does not involve the full height of the lip. ∘ The nostril sill will therefore be intact. • Forme fruste, or microform cleft, is a mild form of incomplete CL. • One or more of the following features may be present in a forme fruste: ∘ A notch in the vermilion ∘ A vertical fibrous band from the wet–dry vermilion border (the red line) to the nostril floor ∘ A kink in the nasal ala on the same side. • Simonart’s band is a soft tissue bridge lying across an otherwise complete CL and alveolus. ∘ There is no consensus definition; the etymology is interesting. ∘ Simonart’s band does not convert a complete CL into an incomplete CL. Anatomy of the unilateral CL nasal deformity • The nasal deformity associated with CL includes: 1 Deviation of the nasal spine, columella and caudal septum away from the cleft side. 2 Dislocation of the inferior edge of the septum out of the vomer groove. 3 Separation of the domes of the alar cartilages at the nasal tip. 4 Dislocation of the upper lateral nasal cartilage from the lower lateral cartilage on the cleft side. 5 Sagging of the lateral crus of the lower lateral cartilage on the cleft side. 6 Retroposition of the alar base on the cleft side. 7 Deficient vestibular lining on the cleft side. 8 Flattening and displacement of the nasal bone on the cleft side. Classification • Popular classification systems include: Descriptive • A ‘say-what-you-see’ classification, such as ‘left unilateral complete CL’. • Can include a schematic diagram showing the relative width and extent of the cleft. Kernahan’s striped ‘Y’ • A graphical classification, likening the CL&P deformity to the letter ‘Y’. • Centred on the incisive foramen, dividing primary from secondary palate. • Each anatomical area is allocated an area on the Y. • Stippling of a box indicates a cleft. • Stippling of half a box indicates an incomplete cleft. • Cross-hatching indicates a submucous cleft. • The original has been modified by many, including Millard, Jackson and Schwartz, to represent submucous clefts, Simonart’s bands and the nasal deformity. The Head and Neck 1 R lip 2 R alveolus 3 R palate anterior to the incisive foramen 4 L lip 5 L alveolus 6 L palate anterior to the incisive foramen 7 Anterior hard palate 8 Posterior hard palate 9 Soft palate R L 1 4 163 5 2 6 3 7 8 9 LAHSHAL • Otto Kriens described this palindromic acronym for clefts. • Represents the Lip, Alveolus, Hard palate and Soft palate. • The letters read from the patient’s right to left. • The second H is sometimes omitted for simplicity. • Upper case letters represent complete clefts. • Lower case letters represent incomplete clefts. • No cleft is represented with a dot. • An asterisk represents a microform cleft. • For example: ∘ . . HSH . . is a complete cleft of the secondary palate. ∘ l . . . . . . is a right-sided incomplete CL. ∘ LA . . . AL is a bilateral complete CL and alveolus. Veau • Described in 1931; classifies CL&P into four groups: ∘ I: Defect of the soft palate alone. ∘ II: Defect of the hard and soft palate (not anterior to the incisive foramen). ∘ III: Defects involving the palate through to the alveolus. ∘ IV: Complete bilateral clefts. Organisation of cleft services in the United Kingdom • Historically, CL&P repair was undertaken by surgeons specialising in plastic, maxillofacial, ENT or paediatric surgery. • In 1996, UK Health Ministers commissioned a study to advise on standards of care for children with CL&P. • The Clinical Standards Advisory Group (CSAG) study findings were published in 1998. 164 Chapter 3 • The results were disappointing: ∘ Many surgeons operated on fewer than 10 cases per year ∘ Almost 40% of patients had poor or very poor dental arch relationship ∘ Only 58% of alveolar bone grafts were successful ∘ 40% of 5-year-old children were in need of treatment for dental caries ∘ 10% of 12-year-old children had persistent symptomatic oral fistulas. • Recommendations were based on ‘good practice’ models from Europe and the United States: ∘ Primary cleft surgeons should see at least 30 new referrals per year ∘ Expertise and resources should be concentrated from 57 to 8–15 units. ∘ Cleft surgeons should have undergone extended CL&P training. ∘ Cleft teams should participate in multicentre audit and research. ∘ Record keeping should be standardised and protocolised. ∘ Both child and family should have access to a range of specialties, including paediatrics, clinical psychology and genetics. • Currently, England and Wales are served by nine different cleft services or networks. • Scotland, Northern Ireland and the Republic of Ireland have their own services or networks. • A modern cleft team comprises the following members: ∘ Cleft coordinator ∘ Plastic surgeon, maxillofacial surgeon and ENT surgeon ∘ Cleft specialist nurse, speech and language therapist ∘ Clinical psychologist, clinical geneticist and audiologist ∘ Paediatrician, paediatric dentist, orthodontist and medical photographer. • Parents may require support from cleft specialist nurses regarding: ∘ Explanation of the diagnosis ∘ Outline of the likely treatment plan ∘ Help and advice on how to feed a baby with a cleft ∘ Psychological and emotional support. Timing of repair • Repair was traditionally performed when the child had attained the three ‘10’s: 1 Weight >10 lb 2 Age >10 weeks 3 Haemoglobin >10 g/dl. • There is little firm evidence to support the optimum timing of cleft repair. • There is little to suggest superiority of neonatal repair. • Palate closure before 8 years affects maxillary growth; closure after this point does not. ∘ However, the aim of palate repair is to allow acquisition of normal speech by 5 years. – This is facilitated by palate repair before speech acquisition begins (with babbling) at 8 months. • Options include: Conventional repair • Lip and anterior palate repaired at 3 months. • Any remaining cleft in the secondary palate is repaired between 6 and 12 months. The Head and Neck 165 Delaire technique • Lip and soft palate repaired simultaneously at 6–9 months. • Remainder of the palate closed at 14–18 months. ∘ May result in better midface growth, as less palate dissection is required at the second operation. Schweckendiek technique • Soft palate repaired at 6–8 months. • Lip repaired 3 weeks later. • Repair of hard palate postponed until 11–13 years. • Excellent midface growth reported because maxillary growth centres are not disturbed. • However, only 28% of patients achieved normal speech. Oslo technique • Lip repaired at 3 months. • Anterior palate and alveolar region closed with a vomerine flap during lip repair. ∘ The vomer flap closes the anterior hard palate and nasal floor in continuity with the lip. • Remaining palate repaired at 18 months with a modified von Langenbeck repair. • Critics of the vomerine flap claim the scar at the vomeropalatine suture limits maxillary growth. Adjuncts to surgery Presurgical orthodontics • Presurgical orthodontics involves the application of devices, which: ∘ Narrow the cleft deformity ∘ Correct alignment of the alveolar processes ∘ Mould the nasal deformity. • Proponents claim that this: ∘ Makes subsequent surgical repair easier ∘ Improves outcome, particularly for the nose. • There are two main types of presurgical orthodontic appliances: 1 Passive appliances – Include obturators or feeding plates. – Prevent displacement of the alveolar arch by reducing distorting forces produced by tongue movement. 2 Dynamic appliances – Include the Latham appliance. • This is pinned into the maxilla intraorally and exerts an active force on the cleft deformity. – Less invasive alternatives include nasoalveolar moulding. • Consists of an intraoral plate with attached nasal moulding bulbs. • Not all units utilise presurgical orthodontics; its use is controversial. • Some reserve it for severe deformities, such as a wide bilateral CL&P. • There is some evidence that presurgical orthodontics may be detrimental to subsequent growth, although this effect is probably largely related to the Latham. 166 Chapter 3 Lip adhesion • Essentially converts a difficult wide cleft into a less difficult incomplete cleft. • Shapes and repositions a protruding premaxillary segment in cases of bilateral CL. • Can also narrow a wide cleft, facilitating definitive repair. • May be done at any age, under local or general anaesthesia. • Skin and mucosal flaps are planned within tissue to be discarded in a definitive lip repair. • Definitive lip repair is planned 3 months later, after the tissues have softened. • Disadvantages include possible need for general anaesthesia, additional scar tissue and dehiscence. Techniques of repair • Principles of management: 1 Optimisation of function – Feeding and growth – Speech – Dentition – Hearing. 2 Optimisation of appearance. • The aims of CL repair are to create: ∘ A lip that moves normally ∘ A lip of normal length and width ∘ Well-aligned anatomical landmarks of the lip: – Vermilion border, wet–dry mucosal junction (red line), white roll, Cupid’s bow, philtral columns, philtral dimple and nasal sill. ∘ Symmetry ∘ Minimal scar. • Each technique lengthens the shortened lip on the cleft side, usually by a form of modified Z-plasty. • The most common techniques are based on either the Millard or Tennison–Randall. • Whichever technique is used, it is important to perform a functional muscle repair: ∘ Detach abnormal muscle insertions ∘ Reconstruct the lip musculature – The nasalis group of muscles should be attached to the anterior nasal spine – The orbicularis group of muscles should be attached to each other. Straight-line techniques • Rose-Thompson • Mirault-Blair-Brown-McDowell Upper Z-plasties • Millard • Delaire Lower Z-plasties • Tennison–Randall • Le Mesurier (rectangular flaps) The Head and Neck Upper and lower Z-plasties • Skoog • Trauner. The Millard rotation–advancement technique The Millard rotation advancement technique (a) (b) (c) C C C R A A R A = advancement flap R C = C flap A R = rotation flap • An upper triangular flap is advanced into the rotation defect of the medial segment. • Advantages: ∘ The scar ‘recreates’ the philtral column ∘ The degree of lip lengthening can be adjusted during surgery – It has been labelled a ‘cut-as-you-go’ technique. ∘ Secondary revision is possible by re-elevation and rerotation of the flaps. • Disadvantages: ∘ It is a difficult technique to master ∘ It places a scar across the philtrum at the nasal base ∘ There is tension at the nostril sill, which can constrict the nostril ∘ Poor results tend to produce lips that are too short. The Tennison–Randall technique (a) (b) (c) 16 3 2 4 8 5 10 1 6 7 9 2 3 4 5 16 7 8 9 10 3 27 49 5 10 8 167 168 Chapter 3 • Described by Tennison; the geometry was elucidated by Randall. • Advantages: ∘ Relatively easy to learn ∘ Maximal tension is below the alveolar ridge, where the lip normally begins to pout. • Disadvantages: ∘ Not easy to adjust the degree of lip lengthening intraoperatively ∘ The philtral column is not restored ∘ Anecdotally more difficult to revise than a rotation–advancement repair ∘ Poor results tend to produce lips that are too long. How to draw a unilateral rotation–advancement repair • Practise drawing both right- and left-sided cleft repairs. (a) Landmarks (b) Flap markings (c) Completed markings H E A B E E D C G F A D C B G F A D C B 1. Identify the landmarks • A – peak of Cupid’s bow on the normal side • B – midpoint of Cupid’s bow, level with the upper lip frenulum • C – peak of Cupid’s bow on the cleft side, symmetrical with A • D – columella base on the cleft side • E – columella base on the normal side • F – the point where the white roll begins to change (not where it disappears) ∘ This indicates where underlying muscle insertions become abnormal. • G – most inferolateral point of the alar base on the cleft side • Line A–E is the philtral column on the normal side ∘ This is the normal length of the lip. • Line C–D is the philtral column on the cleft side ∘ It is shorter than line A–E. • The repair must increase distance C–D to match that of A–E. 2. Draw the rotation flap • The rotation flap is drawn as a curved line between C and D. • It can be extended along the columella base (dotted line). G F The Head and Neck 169 • CD is lengthened by straightening the curved line and opening the back-cut at the columella base. ∘ Some surgeons prefer not to back-cut due to additional scarring. 3. Draw the advancement flap • Draw a line from G to the vermilion border. ∘ This line differentiates nasal from facial skin. – Nasal skin brought onto the face may darken or grow nasal hairs. • The line usually lies perpendicular to the vermilion border. • A straight line joins this line to point F. 4. Draw flaps for the nostril sill • A tangent drawn from the rotation flap into the nose delineates Millard’s ‘c’ flap (H). • This interdigitates with the lip advancement flap and, if done, a vomerine flap. 5. Draw what will be discarded • Points C and F are extended through the lip perpendicular to the vermilion border. • The shaded mucosa is excised because it is not required. • This mucosa would not have existed had the cleft not formed. • It looks abnormal, and is sometimes called ‘sterile mucosa’. Primary nasal surgery • Aims of nasal surgery in CL: ∘ Restore continuity ∘ Restore symmetry ∘ Provide normal function ∘ Allow normal growth. • Correction of the nasal deformity can be performed at any time: ∘ Primary surgery, at the time of lip repair ∘ Delayed surgery, at preschool age ∘ Late surgery, when facial and nasal growth is complete. • Correction in the late teens usually involves an open rhinoplasty approach. • The deformity will be improved to some extent by transposing facial muscles into their normal locations during primary CL repair. • The following techniques have been modified by various surgeons: McComb technique • Presurgical orthodontic treatment realigns the skeletal base. • A ‘hemirhinoplasty’ at the time of lip repair shortens the nose on the cleft side: ∘ Dorsal dissection between nasal cartilages and skin ∘ Release of the cleft side alar cartilage from the piriform aperture ∘ Percutaneous sutures passed through nasal lining into the mobilised alar cartilage, through the dissected subcutaneous space, to exit in the region of the nasion ∘ The suture is tied over a bolster to lift the alar cartilage into its correct position. 170 Chapter 3 Tajima technique • Intranasal, reversed U incision to access alar cartilages. ∘ The incision crosses the alar margin, allowing excision of excess skin causing hooding of the ala on the cleft side. • The deformed alar cartilage on the cleft side is sutured to three points: 1 Ipsilateral upper lateral cartilage 2 Contralateral upper lateral cartilage 3 Contralateral alar cartilage. Anderl technique • The dorsum of the nose is widely undermined to reposition all dislocated structures, including the septum, into their normal position. • Bony augmentation of the hypoplastic piriform aperture is stimulated by dissecting a fold of mucoperiosteum off the inferior turbinate. Alveolar bone grafting • Involves insertion of bone graft into the alveolar gap at the site of the cleft. • It completes the dental arch and stabilises the maxillary segments. • Usually performed when the permanent canine is about to erupt into the cleft. ∘ This occurs at the time of intermediate dentition, approximately 9–11 years of age. ∘ The canine will not erupt correctly into an alveolar defect. ∘ Performing surgery sooner risks damage to the root of the adjacent incisor. • Timing of canine eruption is assessed by: ∘ Observing when the contralateral upper canine is about to erupt ∘ X-ray examination to ascertain the developmental stage of the tooth. • Alveolar bone grafting is done as follows: 1 Raise gingivoperiosteal flaps from the edges of each side of the defect. 2 Separate the oral and nasal cavities by closing mucosa on the nasal side. 3 Harvest cancellous bone graft, usually from the iliac crest. 4 Pack the graft into the alveolar defect. 5 Close the oral side of the mucosa. • Primary bone grafting at the time of lip repair is done in some centres. ∘ This is controversial because: – The bone may resorb – Securing the dental arch early may affect facial growth. • Gingivoperiosteoplasty of the alveolar cleft can be performed at the time of lip repair. ∘ This is also controversial: – Proponents argue that patients do not require secondary bone graft. – Critics argue that it limits maxillary growth. Bilateral cleft lip • Characterised by bilateral defects in the lip, alveolus and anterior hard palate. • The central segment of the lip is the remnant of the medial nasal processes of the frontonasal process, consisting of a: ∘ Soft tissue element called the prolabium ∘ Skeletal element called the premaxilla. The Head and Neck 171 • It contains no muscle because mesenchyme of the second branchial arch could not migrate across the cleft during embryogenesis. • The premaxilla may initially be protuberant as its growth is unrestrained. • However, as the child grows, it becomes relatively hypoplastic. • Historically, bilateral CL repair involved excision of the premaxilla. ∘ Sometimes this was followed by transposition of an Abbe flap. ∘ This resulted in severe deformities of the upper lip and nose. • Other techniques involved fracturing the vomer and setting back the premaxilla. ∘ This affected facial growth, as growth centres were disrupted. Techniques • Presurgical orthodontics may narrow the cleft and align the premaxilla. • Lip adhesion. • Staged surgery to one side before the other for some wide clefts. • The upper buccal sulcus may require reconstruction. • Most techniques are modifications of these two fundamental methods: The Millard repair • This technique is often used if the prolabium is relatively large. • Lip repair at 3 months. • The prolabium is divided into: ∘ A central flap for the philtrum ∘ Lateral forked flaps for the nostril sills. • The vermilion of the prolabium is discarded. • The orbicularis muscles are reconstructed. • The vermilion of the lateral lip elements is sutured in the midline. • The philtral flap of the prolabium is draped over the muscle repair. The Manchester repair • Named after the late Sir William Manchester of Auckland, New Zealand. • His technique may be used when the prolabium is relatively small. • He advocated surgery at 5 months. • The prolabial vermilion is augmented by releasing incisions on the mucosal side. • Straight-line incisions are made either side of the prolabium and lateral lip elements. • The prolabium is sutured to the lateral lip elements in layers. • Muscle within the lateral lip elements is sutured to the dermis of the prolabium. ∘ Manchester argued that suturing muscle in front of the premaxilla caused class III malocclusion. • The hard palate is repaired at the same operation, but soft palate repair is delayed. • Inadequate prolabial vermilion can result in a whistle deformity. Cleft palate Embryology • Palatal development occurs between the 7th and 10th weeks of intrauterine life. ∘ The lip is formed earlier, between the 4th and 8th weeks. 172 Chapter 3 • The palatal shelves of the maxilla are initially orientated vertically. • As the head and mandible grow, the neck straightens and the tongue descends, allowing the palatal shelves to rotate upwards into their usual horizontal position. ∘ This process is delayed in female embryos. ∘ The right palatal shelf becomes horizontal before the left side. ∘ This may explain the higher prevalence of CP in females and left-sided clefts. • If the tongue does not descend, upward rotation of the palate is blocked. ∘ This results in a palatal cleft. • Palatal shelves contact each other and the vomer in the midline at the incisive foramen. • Apoptosis of the epithelial edges is necessary for midline fusion. • Fusion of the secondary palate proceeds posteriorly from the incisive foramen. • Fusion of the primary palate proceeds anteriorly from the incisive foramen. • This explains the pattern of incomplete clefting that is seen in practice: ∘ It is ‘impossible’ to have a cleft hard palate with an intact soft palate or a cleft alveolus with an intact lip. ∘ Such patterns would indicate an acquired cause of oronasal fistulation, such as trauma, infection or previous repair attempt. Anatomy of the palate • The hard palate is composed of: ∘ The palatal processes of the maxilla anteriorly ∘ The palatine bones posteriorly. • It is covered with a dense mucoperiosteal layer. • This mucosa is divided into three distinct anatomical and physiological zones: ∘ Palatal mucosa is thin and located centrally where the palate is horizontal. – It contributes to growth of the palatal shelves prior to their upward rotation. ∘ Maxillary mucosa is thick and located laterally where the palate curves downwards. – It is well vascularised and plays a major role in maxillary growth. ∘ The gingival mucosa lies between the maxillary mucosa and teeth. – It is required for normal eruption of teeth; it contributes little to maxillary growth. • The soft palate separates oropharynx from nasopharynx. ∘ This separation is required for proper speech and swallowing. • It is also called the velum (velum is Latin for ‘veil’). • It contains the following pairs of muscles: • Tensor veli palatini ∘ Originates from the membranous wall of the Eustachian tube. ∘ Its tendon passes around the pterygoid hamulus and gives rise to the palatine aponeurosis, which fuses with the posterior hard palate. ∘ Opens the Eustachian tube. • Levator veli palatini ∘ Originates from temporal bone and Eustachian tube. ∘ Descends to insert from above and behind into the palatine aponeurosis as a sling. ∘ The main functional muscle of the soft palate. ∘ Elevates the soft palate and pulls it posteriorly, closing the opening between nasopharynx and oropharynx. The Head and Neck 173 • Muscularis uvulae ∘ This small muscle lies within the uvula at the centre of the palate. ∘ Elevates and shortens the uvula. ∘ May be small or absent in submucous CP. • Palatopharyngeus ∘ Arises from posterior pharynx, passes through the posterior tonsillar pillar and inserts into the velum. ∘ Lies on the oral side of the levator. ∘ Depresses the soft palate. • Palatoglossus ∘ Arises from the tongue, passes through the anterior tonsillar pillar and inserts into the anterior velum. ∘ Lies on the oral side of the levator. ∘ Depresses the soft palate. • The greater palatine vessels and nerves (branches of V) are the predominant neurovascular supply to the hard palate. ∘ These pass anteriorly and medially from the greater palatine foramina, situated at the posterolateral corners of the hard palate. • The lesser palatine vessels and nerves are the predominant sensory neurovascular supply to the soft palate. ∘ The lesser palatine nerves also supply motor fibres to muscularis uvulae. • Tensor veli palatini is supplied by a branch of V. • The remaining muscles are supplied by the pharyngeal plexus (IX, X and cranial part of XI). Anatomy of the cleft soft palate • Levator veli palatini and other velar muscles run parallel to the cleft margin. ∘ They do not join in the midline to form a sling. ∘ They insert abnormally into the posterior edge of the hard palate. ∘ This leads to impaired velopharyngeal and Eustachian tube function. • Features of a submucous CP include: ∘ Palpable notch in the posterior nasal spine ∘ Zona pellucida, indicative of midline muscle diastasis in the soft palate ∘ Bifid uvula. ∘ Occasionally, a double row of neonatal palatal cysts can be seen, lateral to the zona pellucida. – These epithelial inclusion cysts are called Epstein pearls. – They can be a normal finding in a neonate when they are in the midline. ∘ ‘Occult submucous CP’ describes a palate that looks normal but functions abnormally. Associated syndromes • CP, unlike CL and CL&P, often occurs as part of a syndrome. • Syndromes associated with CP include: ∘ 22q11.2 deletion syndrome ∘ Treacher Collins syndrome ∘ Stickler’s syndrome 174 Chapter 3 ∘ ∘ ∘ ∘ ∘ Apert’s syndrome Crouzon’s syndrome Down’s syndrome Kabuki syndrome Popliteal pterygium syndrome. • PRS is a sequence rather than a syndrome, as one event (a small jaw) results in: 1 Limited tongue descent 2 This in turn prevents upward rotation of the palatal shelves 3 The palatal shelves do not fuse and a wide, U-shaped CP results. • PRS is discussed further in ‘Craniofacial surgery > Atrophy/hypoplasia’. 22q11.2 deletion syndrome • Occurs once in every 2000–5000 live births. • Also known as: ∘ Velocardiofacial syndrome ∘ DiGeorge’s syndrome ∘ Shprintzen’s syndrome ∘ CATCH 22 syndrome – C: cardiac defects – A: abnormal facies – T: thymic hypoplasia – C: cleft palate – H: hypocalcaemia – 22: the genetic abnormality is on chromosome 22. • Diagnosis is made by fluorescence in situ hybridisation (FISH) testing. • Characteristic facial features include: ∘ A long face that is flat both in physical appearance and in expression ∘ Asymmetric facial structure and function ∘ Narrow palpebral fissures ∘ A pinched nasal tip. • It is the most common syndrome associated with CP. • In the absence of an overt CP, submucous CP should be excluded. • Characteristic hypernasal speech and poor speech articulation is typical. • 25% of affected individuals have medially positioned carotid arteries. ∘ This makes surgery on the posterior pharyngeal wall hazardous ∘ Such surgery is done to treat velopharyngeal insufficiency (VPI) in these patients. • Many develop psychological problems in later life. ∘ 30% have an episode of psychosis, and 25% develop schizophrenia. ∘ It is otherwise rare for genetic abnormalities to be associated with psychological illness. Stickler’s syndrome • A group of autosomal dominant genetic disorders affecting collagen. • 75% of cases have mutations in the COL2A1 gene. • Characterised by: ∘ Midface hypoplasia ∘ Cleft secondary palate The Head and Neck 175 ∘ ∘ ∘ High myopia with eventual retinal detachment Congenital hearing loss Arthropathy. • A proportion of patients with Stickler’s syndrome present with PRS. ∘ Any patient found to have PRS should be screened for Stickler’s. – Early ophthalmological intervention can limit potential ocular complications. Surgical repair of CP • Aims of CP repair: 1 Functional reconstruction of the muscles of the palate 2 Separation of the oral and nasal cavities 3 Minimise the incidence of fistula. Hard palate • Repair should minimise scarring and damage to palate growth centres. • In general, the palate is repaired in two layers. • Following repair, there is no bony continuity across the cleft. ∘ Over time, new bone is formed by periosteum within the flaps. • Nasal mucosa is repaired by suturing to the vomerine mucosa. • The following techniques may be used to close the oral surface of the palate: Veau-Wardill-Kilner repair • Also known as ‘the push back’. • Triangular mucoperiosteal flaps, apex anterior, are raised from either side of the palate. ∘ Each flap is based posteriorly on the greater palatine vessels. • The V-Y advancement (‘push back’) was intended to lengthen the palate and improve speech. • However, this is not borne out in practice: ∘ It is criticised for extensive dissection, bone exposure and anterior fistulas. Von Langenbeck repair • Lateral releasing incisions through mucoperiosteum along the inner aspect of each alveolar arch. • Incisions extend from the level of the canine to the posterior alveolar arch, lateral to the greater palatine foramen. • Bipedicled flaps are created between the lateral incisions and medial border of the cleft. • Flaps are transposed medially and sutured together in the midline. • Each flap receives its blood supply from the greater palatine vessels. • Unlike ‘the push back’, it avoids incising the anterior palate. ∘ This area is believed to contain important maxillary growth centres. • More medial placement of the releasing incisions – so-called ‘medial von Langenbeck’ – may be less deleterious to subsequent facial growth. Bardach two-flap repair • Two long flaps are raised that extend to the alveolar margins anteriorly. • Flaps are based posteriorly on the greater palatine neurovascular bundle. 176 Chapter 3 • They are sutured in the midline but not used to achieve ‘push back’. • Proponents claim raising the flaps facilitates exposure of the soft palate muscles. Repair without lateral releasing incisions • The preferred method of Sommerlad where possible (>90% of cases). ∘ Clefts >10 mm wide at the back of the hard palate at 6 months usually require lateral releasing incisions to close. • The ability to close a cleft in this way depends on: 1 Placing sloping palate mucosa into a more horizontal orientation 2 Unfolding mucoperiosteum 3 Mobilising greater palatine neurovascular pedicles 4 Dividing the oral component of the tensor veli palatini insertion. • The reduced dissection may improve subsequent palatal growth. Soft palate • Key points of repair: 1 Detach abnormal muscle insertions into the back of the hard palate 2 Reconstruct the normal muscular sling. Intravelar veloplasty • Preferred method of Sommerlad. • The edges of the cleft are incised. • Soft palate musculature is dissected from the posterior hard palate and overlying mucosa. • The palate is repaired in three layers: 1 Nasal mucosa 2 Muscle, repositioned in the posterior half of the velum – The normal muscular sling is restored by reorienting the muscle fibres. 3 Oral mucosa. Furlow technique • Lengthens the palate by two opposing Z-plasties. • One Z-plasty is based on nasal mucosa. • The second is designed in the opposite direction, based on oral mucosa. • The muscle layer is included in the posteriorly based flap of each Z-plasty. • By transposing the Z-plasties, muscle is repositioned posteriorly. ‘Furlad’ technique • This is slang for an amalgamation of the Furlow and Sommerlad techniques. • Soft palate muscles are treated in the same way as for an intravelar veloplasty. ∘ This formally recreates the muscular sling with reorientation of muscle fibres. • The mucosal layers are each closed by incorporating a Z-plasty. Orthognathic surgery (OGS) • Up to 50% of patients with unilateral complete CP are deemed to require OGS. ∘ This increases to 65% with bilateral CP. The Head and Neck 177 • Problems requiring OGS include: ∘ Occlusal abnormalities, particularly anterior open bite ∘ Constricted maxillary dental arch ∘ Maxillary retrusion ∘ Persistent alveolar defect. Principles of management • OGS is done after skeletal maturity is reached. • Orthodontic treatment is done first, to optimise occlusion and expand the maxillary arch. Surgical approach • Advancement of the maxilla is preferred. ∘ This will treat both the occlusion and midface contour. ∘ It requires a Le Fort I osteotomy. • If midface retrusion is severe, maxillary advancement is combined with mandibular setback. ∘ Mandibular setback can also treat asymmetry and occlusal cant. ∘ It requires a bilateral sagittal split osteotomy. • The segments are held in place with an intermediate occlusal splint. • Alternatively, the segments are attached to a distraction device and gradually moved into their ideal position. • There is a risk of post-operative VPI after maxillary advancement. Velopharyngeal insufficiency • During speech, the soft palate controls air entry into the nasopharynx. • VPI results from inability to fully close the space between soft palate and posterior pharyngeal wall (the velopharyngeal port or orifice). • The sounds M, N and NG are nasal consonants, which require air passage from oropharynx to nasopharynx. • Articulation of the plosives B and P, and the fricatives F and S, requires closure of the velopharyngeal port. • If the soft palate cannot close the velopharyngeal orifice, air escapes into the nose. ∘ This results in characteristic hypernasal speech. • The most common cause of VPI is a cleft secondary palate. • Other causes include: ∘ Submucous CP ∘ Neuromuscular abnormalities ∘ Previous adenoidectomy ∘ Idiopathic congenital VPI. • VPI can cause delayed language development. • Other causes of language delay include: ∘ Hearing difficulty ∘ Other language ‘bad habits’ 178 Chapter 3 ∘ ∘ Global psychosocial delay Tongue restriction. • Language difficulties are therefore best investigated by an MDT. Speech assessment • Formal speech assessment is done once all speech sounds can be produced. ∘ Most children achieve this by 3 years. • Speech and Language Therapists look for characteristic VPI or CP speech: ∘ Abnormal place of articulation – Due to malocclusion or hypodontia as a primary problem. – Due to secondary compensatory techniques learnt to minimise hypernasality, such as using the tongue to lift the soft palate or obturate the cleft. – This can give rise to abnormal added sounds, such as clicks. – It may also manifest as facial grimacing. ∘ Hypernasality – Excessive nasal resonance of an unoperated CP or VPI. ∘ Hyponasality – Decreased nasal resonance heard with adenoid hypertrophy or over-zealous pharyngoplasty. ∘ Nasal airflow errors – These include nasal emission and nasal turbulence. • Nasal emission is audible escape of air through the nose accompanying oral pressure consonants, such as p, f or s. It has a frictional quality. • Nasal turbulence is similar but has a snorting or turbulent quality. • GOS.SP.ASS (Great Ormond Street Speech Assessment) is a speech assessment protocol for CP and velopharyngeal dysfunction. • CAPS-A (Cleft Audit Protocol for Speech-Augmented) is a validated assessment tool for use in multicentre audit studies of cleft speech. Velopharyngeal assessment • Once other causes of language delay are excluded, a formal VPI assessment is done. • Velopharyngeal closure is assessed by: Video fluoroscopy • This is a lateral soft tissue X-ray. • Movement of the soft palate and pharynx is screened in real time. • The following features are noted: ∘ Palate length and thickness relative to the pharynx ∘ Involvement of tonsils and adenoids in palate closure ∘ Abnormal tongue movements, or tongue ‘humping’ ∘ Movement of posterior pharyngeal wall during velopharyngeal closure ∘ The presence of Passavant’s ridge. – Some say this is contraction of the superior pharyngeal constrictor. – Others say it is part of the palatopharyngeus muscle. ∘ The position of the levator, indicated by the ‘genu’ (knee) of the soft palate. ∘ The degree of palate to pharynx contact – how secure the closure appears. The Head and Neck 179 Nasendoscopy • A flexible endoscope is inserted through the nose to the velopharyngeal orifice. • The relationship of the soft palate to the lateral pharyngeal walls can be assessed. • Small openings and areas of scar not detectable on fluoroscopy can be seen. • The pattern and degree of velopharyngeal closure can be visualised. ∘ The surgical plan can be tailored to the pattern of velopharyngeal closure. Treatment of VPI • Nonsurgical treatments of VPI include: ∘ Speech therapy ∘ Prosthetic management with speech bulb or palatal lift appliances ∘ Posterior pharyngeal wall injections or implants. • In general, these do not have a therapeutic role in VPI due to CP. ∘ Abnormal muscle insertions and a short palate cannot be influenced by conservative methods. ∘ Orticochea stated, ‘VPI is like cancer. There is nothing to be gained by waiting to see what will happen’. • Surgical treatment of VPI is based on velopharyngeal assessments: ∘ Palate re-repair to posteriorise the muscular sling ∘ Palatal lengthening with a Furlow if the palate is short ∘ Pharyngoplasty if little palatal movement occurs or the palate is very short. • Most speech surgery is done between 3 and 7 years of age. Pharyngoplasty • Aims to improve closure of the velopharyngeal orifice by altering the pharyngeal wall. • Inspect and palpate the pharynx for anomalous carotid arteries. • Post-operative hyponasality is expected for the first 2–3 months. Posterior wall pharyngoplasties Pharyngeal wall augmentation • Historically, Teflon®, silicone and cartilage have been used. Superiorly based pharyngeal flap • Elevated from the pharyngeal wall and inset into the soft palate. • Passage of air from oropharynx to nasopharynx occurs either side of the flap. • The superiorly based flap is preferred to the inferiorly based one because: ∘ As it contracts, its pull is upwards ∘ Theoretically its nerve supply, which enters from above, is preserved. Inferiorly based flap • The base of the flap is planned high up to avoid downward pull on the soft palate. Lateral wall pharyngoplasties Hynes pharyngoplasty • Two superiorly based flaps from either side of the pharyngeal wall. • Each is 3–4 cm long and includes part of salpingopharyngeus with overlying mucosa. 180 Chapter 3 • Flaps are transposed medially and sutured to each other on the posterior pharyngeal wall. • This creates bulk on the posterior wall, but Hynes reported many patients had a contractile pharyngoplasty. Orticochoea sphincter pharyngoplasty • Superiorly based flaps from the posterior tonsillar pillars. • Each contains the underlying palatopharyngeus. • This is a dynamic pharyngoplasty – preserve the motor supply entering the pedicle. • Flaps are transposed medially and interdigitated into a small, inferiorly based, posterior pharyngeal flap to create a sphincter. • Flaps are not connected to the pharynx laterally, resulting in one central and two lateral ports for passage of air from oropharynx to nasopharynx. Jackson’s modification of the Orticochoea pharyngoplasty • Posterior pharyngeal wall is incised transversely from the superomedial border of one tonsillar pillar flap to the other. • Flaps are inset into the entire length of this posterior incision, leaving no raw areas. • The tips of the flap are sutured end-to-end rather than interdigitated. • This creates a single narrowed central port with no lateral ports. Complications following pharyngoplasty • Major bleeding, due to raw surfaces on the posterior pharynx • Respiratory obstruction • Obstructive sleep apnoea • Persistent hyponasality • Snoring. Head and neck cancer • Squamous cell carcinoma (SCC) of the head and neck arises from the lining membranes of the upper aerodigestive tract. • Other mucosal malignancies include: ∘ Adenocarcinoma ∘ Sinonasal undifferentiated carcinoma (SNUC) ∘ Olfactory neuroblastoma ∘ Malignant melanoma ∘ Lymphoma. TNM classification • Establishes stage grouping and helps determine prognosis and treatment. • N and M classifications are universal for most tumours of the head and neck. • T classifications differ between tumours due to anatomic considerations. T classification for head and neck cancer • T refers to the primary tumour. • Tx: primary tumour cannot be assessed. The Head and Neck 181 • T0: no evidence of primary tumour. • Tis: carcinoma in situ. • For all sites except nasopharynx, T4 is divided into: ∘ T4a (moderately advanced) ∘ T4b (very advanced, invasion of critical structures, not resectable in most centres). • Salivary gland tumours are defined as from parotid, submandibular or sublingual glands. ∘ Extraparenchymal extension is defined as macroscopic rather than microscopic. • Ohngren’s line connects the medial canthus to the angle of the mandible. ∘ Historically, this line was used to divide the maxillary sinus into two: – Anteroinferior tumours have a good prognosis – Posterosuperior tumours have a poor prognosis • This reflects their proximity to the eye and skull base. Nasopharynx Hypopharynx T1 <2 cm Confined to nasopharynx or extends to oropharynx ± nasal cavity <2 cm and confined Limited to sinus to one subsite mucosa T2 2–4 cm Parapharyngeal extension beyond pharyngobasilar fascia 2–4 cm without fixation of hemilarynx or in more than one subsite or an adjacent site T3 >4 cm (±extraparenchymal extension for salivary gland tumours) Invades bony structures ± paranasal sinuses >4 cm or fixation of Invades bone of hemilarynx posterior sinus, orbital floor, ethmoid sinuses or subcutaneous tissues T4 Invades adjacent structures Skull base/intracranial extension and/or cranial nerves Invades other neck or mediastinal structures Oral cavity, oropharynx and salivary gland N and M classification for head and neck cancer • Nx: regional nodes cannot be assessed • N0: no regional lymph node metastases • N1: single ipsilateral lymph node ≤3 cm • N2a: single ipsilateral lymph node 3–6 cm • N2b: multiple ipsilateral lymph nodes <6 cm • N2c: bilateral or contralateral lymph nodes <6 cm Maxillary sinus Invades bone of hard palate ± middle nasal meatus Invades orbital contents, skin, brain 182 Chapter 3 • N3: lymph node >6 cm. • Midline neck nodes are considered to be ipsilateral. • Spread to the lower neck (levels IV and V) is associated with significantly worse survival. ∘ N staging should indicate whether involved nodes are in the upper (U) or lower (L) neck, based on their relationship to the cricoid cartilage. • Prognosis of nodal spread from nasopharyngeal cancers differs from other head and neck cancers: ∘ N1: single ipsilateral lymph node ≤6 cm above the supraclavicular fossa or retropharyngeal nodes ∘ N2: bilateral lymph nodes ≤6 cm, above the supraclavicular fossa ∘ N3a: lymph node >6 cm ∘ N3b: lymph node(s) extending to the supraclavicular fossa – The supraclavicular fossa includes caudal portions of levels IV and V. • The M classification is common to all head and neck SCCs: ∘ Mx: distant metastasis cannot be assessed ∘ M0: no distant metastasis ∘ M1: distant metastasis. • Most common sites of distant spread are lung and bone. • Mediastinal lymph node metastases are considered distant metastases. Stage grouping of head and neck cancer Stage 0 Stage I Stage II Stage III Stage IVA Stage IVB Stage IVC Tis T1 T2 T3 T1 T2 T3 T4a T4a T1 T2 T3 T4a Any T T4b Any T N0 N0 N0 N0 N1 N1 N1 N0 N1 N2 N2 N2 N2 N3 Any N Any N M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M1 Levels of the neck • The neck is divided into the following seven levels. • Some levels are divided into clinically significant sublevels. The Head and Neck 183 Level I: submental and submandibular triangles • Sublevel IA bounded by anterior bellies of both digastrics and hyoid bone. ∘ Contains submental lymph nodes. • Sublevel IB bounded by anterior belly of digastric, mandible and a vertical plane through the posterior edge of the submandibular gland. ∘ Contains submandibular lymph nodes. ∘ The submandibular gland is included in excision specimens from level IB. Level II: upper jugular region • Extends horizontally from level IB to posterior border of sternocleidomastoid (SCM). • Extends vertically from skull base to hyoid. • Divided into sublevel IIA (anterior) and IIB (posterior) by the spinal accessory nerve (SAN). • Contains upper jugular lymph nodes. Level III: midjugular region • Extends horizontally from sternohyoid to posterior border SCM. • Extends vertically from hyoid to lower border of cricoid. • Contains middle jugular lymph nodes. Level IV: lower jugular region • Extends horizontally as for level III. • Extends vertically from level of cricoid to clavicle. • Contains lower jugular lymph nodes, thoracic duct (left) and right lymphatic duct. Level V: posterior triangle • Bounded by posterior SCM, anterior trapezius and clavicle. • Divided by a horizontal plane through the inferior border of the cricoid: ∘ Sublevel VA contains spinal accessory nodes. ∘ Sublevel VB contains transverse cervical and supraclavicular nodes. Level VI: anterior central compartment • Lies between medial borders of each common carotid artery, from hyoid to suprasternal notch. • Contains perithyroidal, pre- and para-tracheal nodes and precricoid (Delphian) node. Level VII: upper mediastinum • Lies outside the boundaries of the neck; its use was discouraged. • However, it continues to be used for the superior mediastinal lymph node group. • Limited to nodes that are an extension of the paratracheal lymph node chain to the level of the innominate artery. • These nodes can be managed through a cervical approach, whereas nodes that extend to the aortic arch require a transmanubrial approach. 184 Chapter 3 Neck dissection • The aim of neck dissection is locoregional control of disease. ∘ Whether it confers a survival advantage is debatable. • Various American surgical societies proposed a classification system based on four main procedures: Radical neck dissection (RND) • Removes ipsilateral lymph nodes from levels I to V. • Also removed are: ∘ SAN ∘ Internal jugular vein (IJV) ∘ SCM. • Level VI and VII nodes are not included. Modified radical neck dissection (MRND) • Removes the same lymph nodes as RND. • It is ‘modified’ to preserve one or more nonlymphatic structures (SAN, IJV and SCM). • Preserved structures are specifically named, e.g. ‘MRND with preservation of SAN’. Extended neck dissection • Removes additional lymph node groups and/or nonlymphatic structures not normally removed with RND. • Examples of additional lymph node groups include: ∘ Superior mediastinal (level VII) ∘ Parapharyngeal and retropharyngeal ∘ Paratracheal ∘ Periparotid and buccinator. • Examples of additional nonlymphatic structures include: ∘ Carotid artery ∘ Hypoglossal and vagus nerves ∘ Paraspinal muscles ∘ Parotid gland. • All additional structures removed are documented in parentheses. Selective neck dissection (SND) • Preserves one or more lymph node level(s) that would otherwise be removed by RND. • Lymph node groups are selected based on patterns of metastases from a particular site of primary disease. • The levels removed are specified, rather than using names such as ‘supraomohyoid’. ∘ ‘Supraomohyoid’ would therefore be documented as ‘SND (I–III)’. SND for oral cavity cancer • The procedure of choice is SND (I–III). • For cancers involving midline structures, bilateral SND (I–III) is recommended. • Invasive oral tongue cancers may justify SND (I–IV). The Head and Neck 185 SND for oropharyngeal and hypopharyngeal cancer • The procedure of choice is SND (II–IV). • These cancers may also involve retropharyngeal lymph nodes. SND for cutaneous malignancies • The operation of choice depends on the location of the primary. • Posterior scalp and upper neck: ∘ SND (II–V, postauricular, suboccipital). • Preauricular, anterior scalp and temporal region: ∘ SND (parotid and facial nodes, II, III, VA and external jugular nodes). • Anterior and lateral face: ∘ SND (parotid and facial nodes, I–III). SND for cancer of midline structures of the anterior lower neck • The procedure of choice is SND (VI). • This includes primaries of thyroid, larynx and pyriform fossa. Indications • This is a controversial area. • There are no randomised controlled trials to guide treatment. • Common sense suggests that neck dissection should be considered: ∘ If access is required to expose neck vessels for free flap anastomosis ∘ In unreliable patients with high-risk tumours – follow-up is not guaranteed ∘ In patients with high-risk tumours and thick necks – clinical detection of nodal metastases may be difficult. • Whether to perform a neck dissection, and extent of surgery, should be made on an individual patient basis by a specialist MDT. The clinically node positive neck (N1–3) • Active treatment is required with combinations of surgery, chemo- or radio-therapy. • Uninvolved levels carry a high risk of occult metastases. ∘ These should be treated prophylactically. • Radical and MRND give equivalent rates of disease control in selected patients. ∘ Localised neck disease may be suitable for SND combined with radiotherapy. • N2 or N3 disease is less likely to completely respond to chemoradiotherapy. ∘ MRND following chemoradiotherapy confers a disease-free and overall survival advantage. • Success of salvage surgery for relapse following radiotherapy is low. The clinically node negative neck (N0) • RND specimens from N0 necks reveal significant rates of microscopic disease. • For all T stages, risk of microscopic nodal spread in a clinically N0 neck is: ∘ >20% for tumours of the oral cavity ∘ >50% for tumours of the oropharynx and hypopharynx. 186 Chapter 3 • Appropriate SND for N0 necks can give equivalent rates of locoregional control to those achieved by MRND. • If an untreated N0 neck should relapse, salvage rates are poor. Technique of radical neck dissection • This is Shah’s method; it is not the only way to clear a neck. Incision • A T-shaped incision is planned: ∘ Transverse limb from mastoid to contralateral SCM – This is two fingers’ breadths below the mandible in a skin crease. ∘ Vertical limb just posterior to the carotid, to midclavicular point. Elevation of the posterior skin flap • Subplatysmal as far as the anterior border of trapezius. ∘ Avoid the external jugular vein. • SAN is seen at the posterior border of SCM in the posterior triangle. Dissection of the posterior triangle • Peel soft tissues medially, exposing the floor of the posterior triangle. • SCM is detached from the mastoid. • Transverse cervical vessels are ligated. • Inferior belly of omohyoid is divided. • Inferior end of external jugular vein is ligated. • Motor branches of the cervical plexus and phrenic nerve are preserved. • The brachial plexus comes into view as dissection is completed. Elevation of the anterior skin flap • Subplatysmal, same as the posterior skin flap. • Sternal and clavicular attachments of SCM are divided. • Preserve branches of internal mammary artery entering the skin flap near the clavicle. Dissection of the carotid sheath • SCM reflected superiorly. • IJV dissected using sharp and blunt dissection. • Proximal end of transverse cervical vessels ligated. • Thoracic duct ligated. • Fascia between carotid sheath and strap muscles is incised. ∘ Strap muscles retracted medially. ∘ Common carotid artery and vagus nerve retracted medially. • Inferior end of IJV can now be doubly ligated. • Middle thyroid vein may enter IJV medially and is ligated. • Dissection continues superiorly along carotid sheath to skull base. ∘ Lymph nodes posterior to IJV are pulled out to remain in continuity with the specimen. The Head and Neck 187 • Hypoglossal nerve is preserved. • Superior belly of omohyoid is detached from the hyoid. • Superior thyroid artery is preserved, but vein ligated. Elevation of the superior skin flap • Marginal mandibular nerve is preserved by retracting it upwards with the skin flap. ∘ Seen overlying the submandibular gland, two fingerbreadths below and anterior to the mandibular angle. • Facial vessels and branches of the occipital artery are ligated. • Contents of the submandibular triangle (level I nodes, submandibular gland, its nerve supply and Wharton’s duct) are dissected. • Lingual and hypoglossal nerves preserved. • Tail of parotid separated or transected along posterior belly of digastric and retracted upwards. • SAN ligated and divided near jugular foramen. • Upper end of IJV doubly ligated, and the specimen is delivered. Closure • After haemostasis, the wound is closed over two suction drains. Complications of neck dissection • With all operations, complications can be divided into: ∘ Intraoperative ∘ Early ∘ Late • Of these, the complications may be: ∘ Specific to the operation ∘ General complications of anaesthesia and major surgery. Specific intraoperative • Bleeding • Carotid artery embolism and stroke • Air embolus ∘ Requires immediate ligation or packing of the open vein. ∘ Turn the patient onto the left side with head down. ∘ Cardiac arrest may necessitate aspiration of air from the heart via a central line. • Pneumothorax • Carotid artery injury ∘ This is repaired intraoperatively. • Hypotension caused by the carotid sinus reflex. ∘ Prevented by injection of local anaesthetic into the adventitia of the carotid bifurcation. • Nerve injury: phrenic, vagus, brachial plexus, lingual, hypoglossal or glossopharyngeal. Specific early • Skin flap necrosis 188 Chapter 3 ∘ If the carotid artery is exposed, it should be covered with vascularised tissue: – Pedicled pectoralis major, deltopectoral or trapezius flap – Free tissue transfer. • Carotid blow out ∘ Usually fatal, more common with salivary fistulas or postradiotherapy. ∘ May be preceded by a sentinel bleed, which mandates surgical exploration. • Salivary fistula • Chylous fistula ∘ Results from damage to the thoracic duct or right lymphatic duct. ∘ Presents with milky drainage from the neck, or a collection. ∘ A fat-free diet can reduce the volume of the leak. ∘ For a large leak, total parenteral nutrition (TPN) usually reduces its volume. Specific late • Scar contracture • Neuroma formation ∘ Usually from cut ends of the cervical plexus. • Shoulder pain syndrome ∘ Its incidence is reduced if the SAN is preserved. • Cellulitis and facial oedema. Management of intraoperative bleeding from the IJV • • • • • • • • • • This is a common examination question. Tell the anaesthetist you have a bleeding problem. Prevent air embolus by controlling the vein with pressure. Try to isolate the bleeding point by: ∘ Suction ∘ Dissection of the surrounding tissues. If possible, repair or oversew the defect in the IJV. If this is not possible, plug the defect with a finger or gauze. Ask your assistant to apply pressure to the area while you finish the neck dissection. If the area continues to bleed, plug it with a segment of SCM. Uncontrollable bleeding may require a thoracic surgeon to enter the superior mediastinum. If the superior IJV is cut, the stump can retract into the temporal bone. ∘ Pack the jugular foramen with Surgicel® and plicate the posterior belly of digastric over the hole. Radiotherapy • Radiotherapy is delivered by: ∘ External beam ∘ Brachytherapy – implanting radioactive devices into the tumour. • The aim is to achieve one of the following: ∘ Cure: radical radiotherapy. ∘ Improving post-operative local control: adjuvant radiotherapy. ∘ Symptomatic relief: palliative radiotherapy. The Head and Neck 189 Radical radiotherapy • In the N0 neck, there is no difference between control rates at 5 years following treatment with either elective neck dissection or prophylactic radiotherapy. • Radical treatment with radiotherapy alone works best for N1 necks. ∘ More than 30% of N2 or N3 necks have microscopic residual disease postradiotherapy. Adjuvant radiotherapy • Adjuvant treatment of N2 or N3 necks can be given before or after neck dissection. • Cases at high risk of recurrence that may warrant adjuvant radiotherapy include: ∘ Oral cavity primary tumours ∘ T3 or T4 lesions ∘ Close or positive surgical margins ∘ Perineural or lymphovascular invasion ∘ Extracapsular lymph node spread. Side effects • Most common side effects in the head and neck are: ∘ Mucositis ∘ Xerostomia, which is often permanent. • Modern 3D CT planning of treatment delivers intensity-modulated radiotherapy. ∘ This minimises collateral radiation damage to adjacent normal tissues. • Osteoradionecrosis is not commonly seen nowadays. ∘ Resection with vascularised reconstruction is the mainstay of treatment. ∘ The original radiotherapy field maps can help plan the extent of resection. Chemotherapy • • • • Indications for chemotherapy in head and neck cancer are not well established. Most often used for tumours at high risk of recurrence. Currently, platinum-containing agents such as cisplatin are most effective. Cetuximab is a monoclonal antibody targeted at the epidermal growth factor receptor. ∘ It confers a 9% survival advantage over radiotherapy alone in T3 and T4 lesions. The unknown primary • Defined as SCC presenting in a neck lymph node with no primary site in the head and neck having been identified. • These comprise less than 5% of all head and neck cancers. • Interestingly, prognosis is better than for cases with a known primary. • Such patients are best assessed in a dedicated neck lump clinic. History • General symptoms: ∘ Weight loss ∘ Cough or haemoptysis ∘ Night sweats suggest lymphoma. • Local symptoms: ∘ Pain, ulceration, trismus or dysphagia may indicate the site of primary. 190 Chapter 3 Examination • General examination: ∘ Cachexia ∘ Metastases. • Local examination: ∘ Palpate, inspect or endoscopically evaluate the nose, postnasal space, oral cavity, tongue base, oropharynx, larynx and hypopharynx. ∘ Look for cutaneous lesions on the head and neck. Investigations Biopsy of the node • US-guided core biopsy is preferred. • Histological architecture can indicate the primary site. • Specific markers can also help locate the primary site: ∘ Epstein Barr Virus (EBV) – nasopharyngeal. ∘ Human Papilloma Virus (HPV-16) – oropharyngeal. • Open biopsy risks tumour spillage – only done if necessary. • Open biopsy incisions should lie along those of subsequent neck dissection. Cross-sectional imaging • PET combined with CT is the investigation of choice. ∘ Identifies the primary in 1∕3 of cases but has a significant false positive rate. • All patients should undergo CT scan from skull base to diaphragm: ∘ To show the extent of lymphadenopathy ∘ To locate a primary tumour ∘ To locate other primaries or lung metastases. Panendoscopy • Panendsoscopy aims to locate the primary and detect synchronous lesions. • It is done after imaging to avoid postsurgical artefact. • It requires general anaesthesia. • Various straight and angled telescopes are used to visualise: ∘ Nose, paranasal sinuses and nasopharynx ∘ Oral cavity, hard and soft palate ∘ Tongue base, tonsil and posterior pharyngeal wall ∘ Vallecula, supraglottis, glottis and subglottis ∘ Pyriform fossa, postcricoid region and proximal oesophagus. • Photographs and deep biopsies are taken from areas showing: ∘ Ulceration ∘ Change in colour ∘ Asymmetry ∘ Fullness. • Random biopsies are also taken from likely primary sites, including: ∘ Pyriform fossa ∘ Nasopharynx The Head and Neck ∘ ∘ 191 Tonsillar fossa Base of the tongue. Tonsillectomy • In the ongoing absence of a primary, ipsilateral or bilateral tonsillectomy is performed. • The combination of whole body PET–CT, panendoscopy with directed biopsy and bilateral tonsillectomy offers the best chance of identifying a primary tumour. Treatment • Most cases require MRND or SND; some require bilateral surgery. • N2/N3 or extracapsular spread requires adjuvant radiotherapy, directed to: ∘ The likely primary sites – ‘total mucosal irradiation’. ∘ The neck, either ipsilateral or bilateral. Radiology Magnetic resonance imaging (MRI) Good at demonstrating abnormalities of soft tissue. Modality of choice for oropharyngeal tumours. T1-weighted images show fat as white and water as black. T2-weighted images show water as white and fat as black. Blood in large arteries moves too rapidly to produce a reliable magnetic resonance (MR) signal. ∘ This causes black ‘flow voids’, used to generate MR angiograms. • Modifications of the basic T1- and T2-weighted scans can suppress distracting signals from fat and free water that might otherwise obstruct pathology in adjacent structures. • These include: ∘ STIR: Short T1 inversion recovery – a fat suppression technique. ∘ FLAIR: Fluid attenuated inversion recovery – suppresses signal from free water. – Used for brain imaging to highlight oedema while suppressing CSF. • Contrast agents are generally gadolinium-based compounds. • • • • • Computed tomography (CT) • CT demonstrates bony detail well. • Density on CT is given a specific value, measured in Hounsfield units (HU). • Air is −1000 HU; water is 0 HU; bones range from hundreds to thousands of HUs. • The Hounsfield scale spans a range of many thousands, whereas most computer displays are only capable of displaying 256 different shades of grey. ∘ CT images are therefore displayed with a modified greyscale. • Changing software settings displays scans at ‘lung windows’ or ‘bony windows’, etc. • Contrast agents are generally iodinated compounds. Positron emission tomography (PET) • Useful for locating occult primary tumours and assessing recurrence. • Produces a map showing levels of glucose metabolism within tissues. • Radiolabelled 16-fluorodeoxyglucose (FDG) is injected intravenously. 192 Chapter 3 • Cancer cells take up more FDG than normal cells; this is detectable by gamma camera. • Modern scanners incorporate CT or MRI to localise uptake to its precise anatomical site. Ultrasound (US) • Uses sound waves with frequencies between 2 and 18 MHz. • Soundwaves are partially reflected when tissue density changes. ∘ Allows visualisation of anatomy. • Can detect occult cervical lymphadenopathy and salivary gland tumours. • Can guide fine needle aspiration (FNA) or core biopsy of suspicious neck lumps. Salivary gland tumours • May take origin from epithelial, mesenchymal or lymphoid tissues. • Salivary glands are classified into two groups: 1 Major salivary glands – Paired parotid, submandibular and sublingual glands. 2 Minor salivary glands – Approximately 1000 small glands throughout the upper aerodigestive tract. • Salivary gland tumours account for approximately 3% of head and neck neoplasms. ∘ 80% occur in the parotid ∘ 80% of parotid masses are benign ∘ 50% of submandibular gland tumours are benign ∘ 20% of sublingual and minor salivary gland tumours are benign. – The smaller the gland, the greater the chance of malignancy. • Benign tumours classically present with a painless, slow-growing mass. • The location of the mass indicates the likely gland involved: ∘ On the face – parotid. ∘ Angle of the mandible – parotid tail, submandibular. ∘ Neck – submandibular. ∘ Floor of the mouth – sublingual. • Malignancy is rare, affecting 1 per 100,000 population per year. • Features of malignancy include: ∘ Pain ∘ Obstruction or infection ∘ Nerve involvement ∘ Invasion of other structures ∘ Bleeding from the duct ∘ Rapid progression. Benign tumours • These lesions are common. Pleomorphic adenoma • Also known as a benign mixed tumour. • Most common salivary gland tumour, accounting for 85% of neoplasms. The Head and Neck • • • • • • • • 193 Represents 70% of parotid tumours and 50% of submandibular gland tumours. Affects individuals of any age; most common in third to sixth decades. Females affected twice more frequently than males. Most commonly affects the tail of the superficial lobe of the parotid. Invasion of the facial nerve is rare. Although seemingly well encapsulated, simple enucleation has high local recurrence rates. Treated with superficial parotidectomy or total excision of a nonparotid salivary gland. Malignant transformation occurs in up to 10% of these tumours. Adenolymphoma • Also known as Warthin’s tumour. • Accounts for up to 15% of salivary gland tumours. • Almost exclusively affects the parotid gland. • Usually arises after middle age, with a male preponderance of 5:1. • Strongly associated with smoking. • 10% of tumours are bilateral. • Most are treated by superficial parotidectomy. Other benign tumours of the salivary glands • Oncocytoma • Sebaceous neoplasms • Intraductal papilloma. Malignant tumours • 80% originate in the parotid. • 10–15% originate in the submandibular gland. • The remainder originates in the sublingual and minor salivary glands. • Carcinomas are classified as high, low or mixed grade. • Excepting mucoepidermoid tumours, clinicopathological correlation is unreliable. ∘ Clinical behaviour, rather than histology, is a better guide to treatment. • Malignant salivary gland lesions are either primary or secondary tumours. ∘ Most secondary tumours are melanoma or SCC of the scalp or ear. • Primary malignancies include: Mucoepidermoid carcinoma • Most common salivary gland malignancy. • Accounts for 30% of malignant parotid tumours, where it usually affects the superficial lobe. • Highest incidence during the third to fifth decade, with no sex difference. • Variable malignant potential; histological grade correlates with lymphatic spread and survival: ∘ Low-grade lesions follow an indolent course, with 86% 5-year survival. ∘ High-grade lesions behave analogous to SCC, with 22% 5-year survival. • Lymph node involvement occurs with 40% of intermediate- and high-grade tumours. ∘ Adjuvant radiotherapy is indicated for high-grade tumours. 194 Chapter 3 Adenoid cystic carcinoma • Most common malignancy of the submandibular and minor salivary glands. • Accounts for 20% of malignant parotid tumours. • Highest incidence during the fourth to seventh decades, with no sex difference. • Has a prolonged clinical course. • There are three distinct histopathological patterns: 1 Cribriform, which may carry a better prognosis 2 Tubular 3 Solid. • Tumour spreads along nerves; skip lesions of the facial nerve are common. • Notable for recurrence many years after initial presentation. • 5-year survival estimates are unreliable due to slow tumour growth. ∘ 20% of patients with pulmonary metastases survive for 5 years or more. • Some believe all patients eventually develop recurrence. • Treatment is by widest possible local excision with preservation of uninvolved major nerves. • Adjuvant radiotherapy is indicated. Acinic cell carcinoma • Accounts for 3% of parotid tumours, where it occurs most frequently. • Peak incidence is in the fifth decade. • Can be multifocal and occasionally bilateral. • Usually low grade and has a 90% 5-year survival rate. • Lymph node metastases occur in 10% of cases. • Treatment is by total parotidectomy with preservation of uninvolved nerves. • Elective neck dissection is not indicated. • Not usually radiosensitive. Malignant mixed tumour • Also known as carcinoma ex pleomorphic adenoma. ∘ In fact, only a minority arises from pleomorphic adenomas. • Tends to be high grade; metastasises via the haematogenous route. • Radical resection with adjuvant radiotherapy is usually required. Other malignant salivary gland tumours • Adenocarcinoma • Primary SCC • Sebaceous carcinoma • Lymphoma. Assessment and staging • This is challenging because 1∕3 of malignancies follow an indolent course. ∘ Clinically indistinguishable from benign lesions. • Diagnosis made on clinical presentation and investigations: The Head and Neck 195 Fine needle aspiration cytology (FNAC) • Can distinguish benign from malignant lesions in 90% of cases. • However, it depends on the skill of the cytopathologist. Imaging • US: to assess primary tumour and lymphadenopathy; guides FNAC. ∘ Its usefulness is operator dependent. • CT and MRI assess anatomy of the tumour and distant metastases. Open biopsy • Avoided in major salivary gland lesions due to tumour seeding. Frozen section • Accurate diagnosis is difficult, but useful for determining clear margins. Technique of superficial parotidectomy • The parotid is divided into superficial and deep lobes by the facial nerve. • 80% of the gland volume is in the superficial lobe. • Using a nerve stimulator helps identify the facial nerve. ∘ The anaesthetist is asked to avoid using neuromuscular blockers. Blair incision • From the anterosuperior border of the ear, along the preauricular crease, continues posteriorly over the mastoid process. • From here it passes anteriorly in a cervical crease towards the hyoid. ∘ Lies 2 fingerbreadths below the mandible. ∘ Short enough to convert into a neck dissection, if required. Elevation of the skin flap • Skin is elevated from the parotid at the level of the superficial parotid fascia. • Inferiorly, avoid damaging great auricular nerve and external jugular vein. ∘ The nerve may subsequently be required as a nerve graft. Separation of the tail and preauricular part of the parotid gland • Tail of parotid is separated from SCM and posterior belly of digastric. • Anything lateral to the posterior digastric is ‘safe’ and can be dissected quickly. • Avoid damaging posterior facial vein – ligation causes venous congestion of the gland. • Parotid is separated from ear cartilage by staying on cartilage down to the tragal pointer. Approach to the facial nerve • The nerve can be approached proximally as it enters the gland (antegrade approach) or distally as it exits the gland (retrograde approach). • Large tumours make it difficult to retract the parotid – a retrograde approach may be preferred. 196 Chapter 3 The antegrade approach • The cartilaginous tragal pointer is visualised. • The facial nerve is found 1 cm deep to this point. • The superficial lobe is separated from the nerve by dissection along the perineural space of each branch. The retrograde approach • Distal branches of the nerve can be identified at the following sites: ∘ The cervical branch runs alongside the retromandibular vein. ∘ The marginal branch lies below the lower border of the mandible. – It runs superficially over the facial artery. ∘ The buccal branches run alongside the parotid duct (Stensen’s duct). – Identification of the duct is aided by cannulation from inside the mouth. • After the gland is freed, the parotid duct is ligated and divided. Technique of total parotidectomy • The superficial lobe is removed as described. • Facial nerve branches are mobilised. • The deep lobe is removed from between the nerve branches. • If there is involvement of the facial nerve, a radical parotidectomy is required. ∘ The facial nerve is included in a radical parotidectomy. • The cut ends of the nerve may be tagged to facilitate nerve grafting. Complications of parotidectomy 1 Facial nerve injury 2 Frey’s syndrome ∘ Gustatory sweating caused by aberrant innervation of cutaneous sweat glands by postganglionic parasympathetic salivary nerves. ∘ Can be minimised by interposition of tissue or acellular dermal matrix between the raw surface of the parotid and overlying skin. 3 Salivary leakage ∘ A collection or fistula affects up to 15% of patients. 4 Ear numbness ∘ A common sequela due to injury of the great auricular nerve. 5 Facial asymmetry 6 Skin flap necrosis. Carcinoma of the lip Anatomy • The lip becomes the oral cavity at the junction of the wet and dry mucosa. • Labial arteries form a continuous loop around the lip. ∘ Located just beneath the mucosa on the lingual side. • Lymphatic drainage is mainly to submandibular nodes. The Head and Neck 197 • The commissure may drain to periparotid nodes. • The midline lower lip drains to submental nodes and may cross the midline. Pathology • SCC is the most common tumour affecting the lip. ∘ Associated with long-term sun exposure. • Lip SCC behaves more analogous to cutaneous SCC than intraoral SCC. • Most tumours occur on the lower lip, possibly due to more sun exposure. • Most upper lip tumours are basal cell carcinomas (BCCs). • Large tumours (>2 cm) and those arising from mucosa are more likely to involve underlying muscle. ∘ This affects 5-year survival: 75–80% for T1–T2; 40–50% for T3–T4. Excision • UK guidelines recommend resection margins of ≥6 mm. ∘ Large or poorly differentiated tumours require wider excision. • Early stage lesions are equally well treated by surgery or radiotherapy. ∘ Radiotherapy may be preferred for small tumours around the commissure, as function may be difficult to restore after resection. • Tumours fixed to bone should be imaged preoperatively. Reconstruction • In 1920, Sir Harold Gillies stated these principles of lip reconstruction: ∘ ‘Restoration is designed from within outwards. The lining membrane must be considered first, then the supporting structures, and finally the skin covering’. • Reconstructing lip with lip tissue is preferable. • Reconstituting orbicularis oris gives a functional reconstruction. • Function is more important in the lower lip than the upper lip. ∘ A static upper lip contributes to oral continence if the lower lip is normal. • Lesions limited to mucosa can be managed by vermilionectomy (‘lip shave’) and mucosal advancement. • Small lesions (<2 cm) invading adjacent muscle are amenable to wedge excision and direct closure. ∘ W-plasty can avoid crossing the mental crease with a wedge excision. • Generally, defects are closed directly where possible. ∘ 25% of the upper and 30% of the lower lip can be directly closed ∘ This is a guideline – different individuals have varying degrees of tissue laxity. • If direct closure is not possible, tissue can be introduced from the intact lip to reconstruct defects up to 2∕3 of the horizontal width using one of the following techniques: ∘ Abbe or Abbe–Estlander. ∘ Karapandzic or reverse Karapandzic, preserving the nerve supply to orbicularis. ∘ Perialar crescentic flap for the upper lip. 198 Chapter 3 Lip reconstruction Abbe lip switch flap Abbe-Estlander Karapandzic Perialar crescentic flap Excise Excise The Head and Neck • Larger defects can be reconstructed as follows: Upper lip • Combinations of flaps, e.g. Abbe with perialar crescentic flap • Nasolabial transposition. Lower lip • Gillies’ fan flap • Webster-Bernard • Nasolabial transposition. • Free tissue transfer may be required for total lip defects. • Lip reconstructions often require revision to shape the commissure. Gillies’ fan flap a b b a c c Webster-Bernard Excise Excise (partial thickness) Mucosal flaps for vermilion Nasolabial transposition 199 200 Chapter 3 Tumours of the oral cavity Anatomy • Extends anteriorly to the wet–dry border of the lips. • Extends posteriorly to the junction of hard and soft palate and circumvallate papillae of the tongue. • The oral cavity contains: ∘ The inner aspect of the lips ∘ Buccal mucosa ∘ Alveolar ridges ∘ Floor of the mouth ∘ Retromolar trigone ∘ Hard palate ∘ Anterior 2∕3 of the tongue. Aetiology and pathology • Oral malignancies account for 30% of head and neck cancer. ∘ Most are SCCs. • Present as nonhealing ulcers or mass lesions. ∘ Advanced tumours can present with loose teeth, trismus or referred otalgia. • SCC may arise de novo or from a premalignant lesion. • Associated with: ∘ Tobacco ∘ Alcohol ∘ Local trauma ∘ Oral HPV-16 infection ∘ Betel nut. • Premalignant lesions specific to oral SCC are: ∘ Leukoplakia – A white patch, which, unlike lichen planus, cannot be scraped off. • Diagnosis of exclusion. – Epithelial dysplasia is present in 25% of leukoplakia biopsies. – Up to 20% of these lesions undergo malignant transformation. – Biopsy is essential: dysplastic leukoplakia is excised; nondysplastic lesions can be observed. ∘ Erythroplakia – A red patch with a soft, velvety texture. • Also a diagnosis of exclusion. – Epithelial dysplasia or invasive SCC is present in almost all erythroplakia biopsies. – The threshold for excision of these lesions is lower. • General premalignant conditions can be inherited or acquired: The Head and Neck 201 Inherited • Fanconi’s anaemia ∘ Rare autosomal recessive disorder prevalent in Ashkenazy Jews and Afrikaners. ∘ High risk of developing oral SCC, particularly after stem cell transplantation. ∘ Oral SCC can occur as early as 11 years. ∘ Requires screening for head and neck SCC every 3 months. • Li–Fraumeni syndrome ∘ Rare autosomal dominant disorder linked to mutations in the p53 tumour suppressor gene. Acquired • Immunodeficiency due to AIDS, medication or poor nutrition. Management • Planned by an MDT, including the patient. ∘ Curative or palliative intentions should be made clear. • History and examination using a systematic approach. • Imaging – MRI is the modality of choice for oral malignancy. ∘ Plain X-ray or CT chest may show metastasis or lung primaries. • Staging (TNM). • Routine panendoscopy, looking for synchronous tumours, is contentious. Treatment • T1 and small T2 tumours can be treated with either surgery or radiotherapy. • Treatment choice is influenced by: ∘ Fitness for anaesthesia and surgery. ∘ Tumour size and location. ∘ Depth of invasion. ∘ Proximity to bone (radiotherapy can cause osteoradionecrosis). ∘ Growth patterns. ∘ Presence of neck nodal disease. ∘ Patient choice and convenience. • Advanced disease (T3, T4 or nodal disease) is usually managed by: 1 Surgical resection of the primary 2 Neck dissection 3 Reconstruction 4 Post-operative radiotherapy, ideally starting within 6 weeks of surgery. • Tumour should be resected with clinical margins of 1 cm, vital structures excepted. • A ‘close’ margin is defined histologically as <5 mm. ∘ This usually requires adjuvant treatment or further resection. Reconstruction • Priorities of reconstruction include: ∘ Restoring a continuous lining to the oral cavity. 202 Chapter 3 ∘ ∘ ∘ Maintaining oral continence. Maintaining speech and swallowing function. Providing an acceptable aesthetic result. • Choice of reconstruction depends on prior surgery, radiotherapy and the patient’s general health. Free tissue transfer • The mainstay of oral soft tissue reconstruction. • Radial forearm flap (RFF) ∘ Large, thin, pliable flap. ∘ Multiple skin paddles can be designed. ∘ Can be raised as cutaneous, fasciocutaneous, fascial or osseocutaneous flap. – Availability of bone is minimal. ∘ The donor site can be troublesome if a large flap is required. • Anterolateral thigh (ALT) flap ∘ Provides a large volume of tissue. ∘ Cutaneous, fasciocutaneous and fascial flaps can be raised with vastus lateralis if required. ∘ Long pedicle that may be septocutaneous or musculocutaneous. ∘ Depending on habitus it may be relatively thick, but can be thinned. ∘ Donor site morbidity is minimal; numbness of the thigh is usual. • Latissimus dorsi flap • Rectus abdominis flap • Scapular/parascapular axis flaps. • Commonly used recipient vessels in the head and neck: ∘ Facial artery ∘ Superior thyroid artery ∘ Superficial temporal artery ∘ Transverse cervical artery. Local and regional flaps • Local mucosal flaps • Facial artery musculomucosal (FAMM) flap • Pectoralis major flap • Deltopectoral flap • Nasolabial flap. • Small defects may be closed directly or with skin grafts. Mandibular reconstruction • Floor of mouth tumours frequently involve the mandible. • Treatment planning should consider the following: ∘ Does the mandible require resection? ∘ How much resection should be undertaken? • Factors influencing management include: ∘ Proximity of the primary tumour to the mandible. ∘ Whether the mandible is dentate or edentulous. The Head and Neck ∘ ∘ ∘ 203 Degree of alveolar atrophy. Previous radiotherapy. Whether the tumour has invaded the mandible. Pathology • Mandibular periosteum is resistant to tumour spread. • In the dentate mandible, invasion occurs via the tooth sockets. ∘ Presence of teeth is a relative barrier to tumour invasion. • Invasion of the edentulous mandible occurs through the occlusal surface. ∘ Resorption of alveolar bone gives tumours a shorter route to the occlusal surface of edentulous mandibles. • Radiotherapy disrupts the barrier function of mandibular periosteum. ∘ Invasion can therefore occur directly through irradiated cortical bone. • Proximal–distal spread within cancellous bone is usually limited to within 5 mm of overlying soft tissue involvement. ∘ 5–10 mm margin of bone resection beyond the overlying soft tissue involvement is adequate. • However, tumour involvement of the inferior alveolar canal allows extensive perineural spread. ∘ Tumour can involve the skull base in this way. • Adequacy of planned clinical margins is confirmed by imaging. Excision • For tumours >1 cm from the bone, no mandible resection is required. Marginal resection • Resection of alveolar ridge ± lingual plate, sparing inferior alveolar nerve. • For tumours <1 cm from bone, marginal resection ensures 1 cm margins. • For tumours involving gingival mucosa or periosteum, marginal resection ensures any subclinical bone involvement is resected. • Not suitable for edentulous mandibles with alveolar resorption: ∘ The remaining bone would be critically weakened, risking fracture. • Also not suitable for irradiated mandibles because patterns of tumour spread are unpredictable. Segmental resection • Required if tumour is fixed to the occlusal surface or has invaded bone. • The inferior alveolar nerve is assessed by frozen section if there is extensive invasion. ∘ Bony excision may be extended if the nerve is involved. Reconstruction • Consider: ∘ Site and size of the defect ∘ Associated soft tissue loss ∘ Goals for dental rehabilitation. 204 Chapter 3 • Mandibular defects are classified using the HCL method (Jewer et al.) as follows: ∘ C (central) – segment between the distal surfaces of the canine teeth. ∘ L (lateral) – lateral segment not including the condyle. ∘ H (hemimandible) – lateral segment including the condyle. • Defects are commonly a combination of segments, e.g. LCL. Free tissue transfer • The mainstay of mandibular reconstruction. Fibula flap • Longest piece of vascularised bone available. • Classified as a Mathes and Nahai type V flap: ∘ Dominant nutrient artery from the peroneal artery. ∘ Segmental periosteal pedicles along the length of the bone. • Bone can be safely contoured by multiple osteotomies due to the segmental supply. • Peroneal septocutaneous vessels can supply a skin paddle if required. Deep circumflex iliac artery flap (DCIA) • Suitable for hemimandible reconstruction. ∘ The curve of the iliac crest means osteotomy may be unnecessary. • Classified as a Mathes and Nahai type I flap. • The skin overlying the flap is not always reliable. • A segment of internal oblique may be included in the flap. • Donor site can be problematic; hernias and numbness reported. Scapular flap • Based on the subscapular axis. • Can include up to 14 cm of the lateral border of the scapula. • Large volume of skin and muscle can be taken. • Simultaneous two-team resection and harvest is not usually possible. Radial forearm flap • Less than ideal bone due to its low height. • Up to 10 cm of bone involving 40% cross section of the radius available. • Risk of subsequent fracture of the radius. Pedicled transfer • Segment of clavicle, pedicled on SCM. • Segment of the spine of the scapula, pedicled on trapezius. • Segment of rib or sternum, pedicled on pectoralis major. Reconstruction with nonvascularised bone • These techniques are not ideal and require a vascular bed: ∘ Bone graft from rib or iliac crest. The Head and Neck 205 ∘ Freeze-dried, autoclaved or irradiated allograft mandible. • Historically, titanium or Dacron trays containing cancellous bone graft were used. Reconstruction without bone • Segmental bony defects can be spanned with contoured reconstruction plates. • These are rigidly fixed to bone at either end of the defect. • They may be temporary or permanent. • Best suited to patients who: ∘ Are not suited to other methods of reconstruction. ∘ Have lateral defects. ∘ Have good soft tissue coverage. ∘ Have not received and will not receive radiotherapy. • Dental reconstruction is not possible. • Risk of infection and extrusion. Tumours of the nasal cavity and paranasal sinuses • • • • • • • Rare; affect less than 1 per 100,000 population per year. More common in the Far East. Most common sites: lateral nasal wall, ethmoids and maxillary sinus. Proximity to orbit and cranium makes management difficult. Delayed presentation is common. Early symptoms: nasal blockage, bloodstained discharge and anosmia. Late symptoms: proptosis, diplopia, epiphora, trismus, oroantral fistula, pain and paraesthesia. Primary tumours • Heterogeneous group; SCC is the most common. Epithelial tumours • SCC • Adenocarcinoma • Olfactory neuroblastoma • Malignant melanoma • Adenoid cystic carcinoma. Sarcomas • Chondrosarcoma • Rhabdomyosarcoma. Benign tumours • Inverted papilloma. ∘ Most common sinonasal pathology. ∘ Locally aggressive tumour of the nasal cavity. ∘ 2% risk of malignant transformation; high risk of recurrence. 206 Chapter 3 ∘ • • • • • • • Specialist histopathology review is required: – Well-differentiated SCC is easily mistaken for inverted papilloma. Juvenile angiofibroma. ∘ Slow growing but locally invasive vascular tumour. ∘ Usually arises from the sphenopalatine region of adolescent males. ∘ Can cause life-threatening epistaxis. Osteoma Haemangiopericytoma Haemangioma Schwannoma Pleomorphic adenoma Meningioma. Management • Planned in a skull base MDT. • Assessment and staging with MRI and CT scan. • Biopsy to confirm the presence of a tumour. • Adjuvant radiotherapy commonly used for malignancies Excision • Extent of resection is tailored to the individual tumour. • Most benign lesions accessed through a midfacial degloving approach. • Frontal sinus or ethmoid tumours may require a combined craniofacial approach. • Surgery is contraindicated for aggressive tumours involving cavernous sinus, internal carotid artery or massive intracranial extension. Reconstruction • The aims are to: 1 Achieve dural seal 2 Separate the aerodigestive tract from the intracranial space 3 Re-establish orbital and oropharyngeal cavities 4 Restore form using skeletal support, soft tissue bulk and overlying skin 5 Obliterate dead space. • Maxillectomy defects require obturation with either a prosthesis or biological tissue. • Prostheses for large, complex defects are difficult to fit and retain. ∘ They are best suited to small defects; flaps are favoured for large defects. • Brown’s revised classification of maxillectomy defects helps guide treatment: ∘ I: maxillectomy not causing oronasal fistula ∘ II: not involving orbit ∘ III: involving orbital adnexae with orbital retention ∘ IV: with orbital enucleation or exenteration ∘ V: orbitomaxillary defect ∘ VI: nasomaxillary defect. The Head and Neck II II III IV V VI 207 Source: Brown and Shaw (2010). Reproduced with permission of Elsevier. • Skull base and dural defects require a multilayered technique using: ∘ Fascia ∘ Cartilage ∘ Fat ∘ Split calvarial bone ∘ Local mucosal flaps. Reconstruction of the nose • The nose grossly consists of three layers: 1 External skin 2 Midlayer of bone and cartilage for support 3 Lining, largely mucoperichondrium. • Reconstruction should replace the missing elements of this trilamellar structure. • Reconstruction should not obstruct the nasal airway. • Patients unwilling or unable to undergo autologous reconstruction can have a prosthesis. 208 Chapter 3 Skin • Nasal aesthetic subunits were described by Burget and Menick: ∘ Dorsum ∘ Tip ∘ Columella ∘ Paired sidewalls ∘ Paired alae ∘ Paired soft triangles. • Reconstructing whole subunits may produce better aesthetic results. Small, superficial defects • Small defects can be left to heal or closed primarily. • Full thickness skin grafts give good results in the upper 2∕3 of the nose. ∘ Suitable donor sites include forehead, preauricular and supraclavicular areas. • Composite chondrocutaneous grafts from the ear helix can be used for alar rim and columella. ∘ This part of the ear can also been transferred as a free flap. • Local flaps from the nose are limited to 1.5–2 cm defects: ∘ Transposition flaps, such as a banner flap ∘ Bilobed flap ∘ Rotation–advancement flaps of the nasal dorsum and glabella ∘ Nasolabial flap. Large, deep defects • The nasolabial flap can be used as a one- or two-stage procedure. • The paramedian forehead flap is considered the gold standard: ∘ Has been refined and described in detail by Menick. ∘ Gives excellent texture and colour match. ∘ Usually pedicled at the medial eyebrow, based on supratrochlear vessels. ∘ Transferred in two or three stages. ∘ Any donor site that cannot be closed is left to heal. • If forehead skin is not available, free flaps can be used. Support • ‘Scaffolding’ for nose shape; it resists scar contracture. • Components that may be required include: ∘ Dorsal buttress ∘ Sidewall brace ∘ Tip grafts for projection and definition ∘ Alar batten grafts to prevent rim collapse. • Common materials used include: ∘ Nasal septal cartilage ∘ Ear conchal cartilage ∘ Costal cartilage. The Head and Neck 209 • Rib or split calvarial bone graft can be used as a cantilever for dorsal support. • Use of synthetic materials in the nose has a poor track record. Lining • Inadequate reconstruction of lining causes scar contraction and distortion. • Lining material should be thin, supple and vascular: • Local hingeover flap ∘ Skin or scar tissue adjacent to the defect can be turned over based on the defect edge. ∘ It is stiff and prone to necrosis, making it useful only for small rim defects. • Intranasal lining flaps ∘ Can be small random pattern flaps or larger axial flaps of mucoperichondrium. ∘ Small defects of the alar rim can be lined with an adjacent bipedicled flap. – The donor site must be resurfaced with skin graft to prevent late contracture. ∘ Larger septal flaps based on the anterior ethmoidal artery, hinged from one half of the nose to the other. ∘ Composite flaps of the entire septum based on septal branches of the right and left superior labial arteries. – Composite flaps provide both support and lining. • Skin grafts ∘ Can be placed on the deep surface of a forehead flap. ∘ Full thickness grafts are preferred due to lower rates of secondary contracture. ∘ After 3 weeks, grafts are vascularised by adjacent nasal mucosa. – They can then be separated from the flap if required, e.g. to insert cartilage. • Folded forehead flap ∘ The distal flap can be folded on itself at the alar rim to provide both lining and cover. ∘ After 3 weeks, the folded part of the flap is vascularised by the adjacent nasal mucosa. – The fold can therefore be divided and thinned without compromising blood supply. • A second flap ∘ Could be a second forehead flap, nasolabial or FAMM flap. • A free flap. Maxillofacial trauma • Maxillofacial trauma is common and incidence is increasing. • Causes of maxillofacial trauma in the United Kingdom are the following: 1 Interpersonal violence (52%) 2 Sports injuries (19%) 3 Road traffic collisions (16%) 4 Falls (11%) 5 Industrial accidents (2%). • Incidence of maxillofacial trauma due to road traffic collisions has decreased. ∘ Attributed to stricter legislation and car safety innovations. • Incidence of maxillofacial trauma due to interpersonal trauma and falls is increasing. ∘ Associated with recent consumption of alcohol in over 1∕3 of cases. 210 Chapter 3 General management principles • • • • • • • Effective early management of life-threatening injuries. Accurate diagnosis. Early single-stage surgery. Thorough exposure of all bony fragments through cosmetic incisions. Precise internal fixation. Immediate bone grafting where necessary. Reconstruction and resuspension of soft tissues. Initial management • Care of all trauma patients begins with an Advanced Trauma Life Support (ATLS)-style primary survey. ∘ The purpose of the primary survey is to identify and treat all immediately life-threatening conditions. • Facial injuries should raise suspicion of: ∘ Cervical spine injury, found in up to 10% of facial trauma cases. ∘ Ocular injury, found in up to 10% of facial trauma cases. ∘ Airway compromise. ∘ Brain injury. • Specific facets of the primary survey in the context of facial trauma include: Airway with cervical spine control • Cervical spine is triple immobilised with hard collar, sandbags and tape. • Avoid blind nasal intubation: risk of aggravating bleeding and intracranial placement of the tube. ∘ Fibre optic-assisted intubation is often required. • Airway compromise may be due to: ∘ Laryngeal injury – Requires tracheostomy. ∘ Foreign bodies – Remove and retain to determine whether teeth or bone fragments are missing. ∘ Bleeding from the upper airway – Due to comminuted fractures of mandible or maxilla. – Disimpacting the fracture helps stop the bleeding. – Pulling on the symphysis menti brings the genial tubercles and attached tongue forward and re-establishes the airway. • A tongue stitch may be required to maintain it in a forward position. Breathing • The chest X-ray is inspected to rule out aspiration of teeth. Circulation with haemorrhage control • Haemorrhage can be controlled with direct pressure. • If this fails, packing the nasal and postnasal cavities is required. The Head and Neck 211 • If bleeding persists, haemostatic resuscitation is initiated. • Facial bandaging may be required. ∘ Involves packing oral and nasal cavities and applying circumferential facial bandaging. ∘ The patient remains intubated in ICU until removal of the packing is deemed safe. • Ongoing haemorrhage is best dealt with by angiographic embolisation. Disability • Brain injury is a leading cause of death in facial trauma. • Facial fracture surgery is avoided if there is evolving head trauma. • The head should be imaged with CT as soon as possible. • Conscious level is monitored using the Glasgow Coma Scale (GCS). Assessment History • Take an ‘AMPLE’ history. • Mechanism of injury: high or low energy; blunt or penetrating. • Loss of consciousness or limb weakness. • Facial paraesthesiae, numbness or paralysis. • Abnormalities of bite or occlusion; trismus. • Ocular symptoms: visual disturbance, diplopia and pain. • Tinnitus or vertigo. Examination • This should be logical and systematic. • Swelling often impairs assessment. • A photographic record is helpful. Skull vault • Laceration, haematoma or crepitus may indicate skull fracture. Face • Elongated facial appearance suggests high Le Fort injury. ∘ Palpate the maxilla for crepitus or movement. • Examine from above and behind the patient for depression of the zygomatic arches and associated enophthalmos. ∘ A depressed zygomatic arch may cause trismus, due to impingement of the mandibular coronoid process. • Surgical emphysema may indicate fracture into a paranasal sinus. ∘ Air may also track to the face following injury to the larynx, trachea or lung. • Test cranial nerve function, especially V and VII. ∘ Includes specific sensory examination of the branches of V: – Supra- and infra-orbital, supratrochlear, zygomaticofacial, zygomaticotemporal and mental. 212 Chapter 3 Eyes and orbits • (Formal ocular assessment is best carried out by an ophthalmologist.) • Fractures produce crepitus or a palpable step in a bony rim. • Periorbital subcutaneous emphysema is a feature of orbital wall fractures. • Look for asymmetry, exophthalmos, enophthalmos, hypoglobus, orbital dystopia and telecanthus. • Look for injuries to the eyelids, conjunctiva, lacrimal system and canthal ligaments. ∘ The ‘bow-string’ test pulls the eyelid laterally – lack of resistance suggests medial canthal ligament injury or underlying fracture. • Evert the eyelids, look for corneal injuries with fluorescein and blue light. • Asymmetry of the iris, vitreous haemorrhage or hyphaema indicate globe injury. • Subconjunctival haemorrhage without posterior limit is characteristic of tetrapod fractures of the zygoma. • Red colour desaturation is an early sign of optic nerve compression. ∘ Ask the patient whether they perceive a difference in the intensity of a red light with alternate eyes closed. • Record visual acuity and fields, eye movements, pupil reactivity and relative afferent pupillary defect (RAPD). • A RAPD is tested for using the ‘swinging flashlight test’: ∘ Under normal circumstances, shining light into one eye causes both pupils to constrict: this is the consensual pupillary reflex. ∘ Swinging a flashlight from one eye to another normally maintains both pupils in a constricted state. ∘ If the retina or optic nerve is injured on the left side, the pupillary response will be normal (consensual) when light is shone into the right eye. ∘ When the flashlight is quickly swung over to the left eye, the brain is unable to perceive the shining light and responds by dilating both pupils. – This is known as a Marcus Gunn pupil. ∘ In contrast, if there is injury to the oculomotor nerve on the right side, the right eye cannot effect pupillary constriction. – However, an uninjured left eye will constrict when light is shone into either eye. • Retrobulbar haematoma is an emergency that manifests as: 1 Severe pain in the eye 2 Progressive loss of vision (especially colour vision) 3 RAPD 4 Proptosis 5 Tense orbit 6 Subconjunctival haemorrhage without posterior limit 7 Periorbital oedema. • Emergency sight-saving treatment involves bedside lateral canthotomy: ∘ Lignocaine with epinephrine is injected into the lateral canthus. ∘ Make a 1–2 cm cut out of the lateral corner of the palpebral fissure with scissors. ∘ Cantholysis divides inferior and superior limbs of the lateral canthal tendon. ∘ Transfer to the operating theatre for formal exploration. ∘ Urgent ophthalmology review is required. The Head and Neck 213 • Superior orbital fissure syndrome is a consequence of severe force to the lateral orbit. ∘ Leads to pinching of neurovascular structures between the edges of the superior orbital fissure, akin to closing the blades of a scissors, causing: 1 Palsies of III, IV, VI and nerve to levator palpebrae superioris 2 RAPD 3 Mydriasis and loss of the corneal reflex 4 Altered sensation on the forehead. • Orbital apex syndrome is similar but also involves the optic nerve. Nose • Look for fracture or dislocation of the nasal septum. • Epistaxis may indicate nasal or paranasal sinus fracture. • Drain septal haematoma to avoid septal necrosis. • Telecanthus and ‘saddle-nose’ deformity may indicate nasoethmoidal fracture. • Straw-coloured nasal drainage suggests CSF leak. ∘ Diagnosis is confirmed by: – Analysis of fluid for beta-2 transferrin. – Neuroradiological imaging with intrathecal contrast. – Intrathecal injection of fluorescent dyes. – Comparing fluid glucose level to the patient’s serum glucose. • CSF rhinorrhoea indicates fracture communication with the anterior cranial fossa. Ears • Battle’s sign over the mastoid tips suggests basal skull fracture. • Otoscopy: haemotympanum, rupture of the tympanic membrane, CSF otorrhoea, wounds of the external auditory meatus. • Subcutaneous haematoma of the pinna is drained to prevent ‘cauliflower ear’. Mouth • Check for loose or missing teeth, foreign bodies and dentures. • Malocclusion and lacerations of the gingivae and tongue suggest mandible fracture. ∘ Check for paraesthesia or numbness of the inferior alveolar nerve. ∘ Sublingual haematoma is pathognomonic of mandible fracture. • Bimanual compression at the mandibular angles may highlight fractures. • The ‘tongue blade test’ is 95% sensitive and 65% specific for mandible fractures: ∘ The patient bites down on one end of a wooden tongue depressor. ∘ The examiner tries to bend the depressor to breaking point. ∘ Patients with mandible fractures cannot do this without considerable pain. Imaging • In general, CT is the imaging modality of choice. • CT is close to 100% sensitive and specific for facial fractures. ∘ Gives excellent 3D information to assist surgical planning. • Images take minutes to acquire, unlike a series of facial X-rays. • CT does not require cervical spine clearance, unlike some facial X-rays. 214 Chapter 3 • The one exception is mandible fractures. ∘ Tooth and root details are better demonstrated on plain X-ray. ∘ These are imaged with orthopantomogram (must include condyles) and PA X-rays. • The cervical spine may also require imaging. Management of facial soft tissue injuries Skin • Usually requires only minimal debridement and suture. • Dirt and foreign bodies must be removed to avoid tattooing. Eyelids • Require layered closure. • Conjunctiva can be left to heal without sutures. • Consider a Frost suture to protect the cornea. • Lacrimal canaliculus injury can be demonstrated by irrigating fluorescein-stained saline into the punctum and looking for dye in the wound. • The lacrimal system may be repaired as follows: 1 Dilate the punctum to allow passage of a Bowman probe to highlight the injury. 2 Intubate the injured duct with a soft silicone stent, e.g. Mini-Monoka. 3 Suture the duct around the stent. 4 The stent can be removed after 2–3 months. • Coexisting injury to the medial canthal ligament must also be repaired. Ears • Suturing the skin usually brings the cartilage into alignment. • Through-and-through bolster sutures may help avoid pinna haematoma. • Total amputations may be suitable for microsurgical replantation. ∘ Most composite grafts fail. Nose • Unlike the ears, suturing the skin is unlikely to restore cartilage alignment. • Anatomical restoration and layered closure are required. Lips • Layered closure to restore muscular continuity. • Anatomical restoration of lip landmarks is essential. Facial nerve • Repair of facial nerve branches is easier within 48–72 hours of injury. ∘ Allows distal nerve stumps to be identified by stimulation. • Branches medial to the lateral canthus are usually too arborised for accurate repair. ∘ Most undergo spontaneous reinnervation at this level. • Nerve grafts may be required to bridge segmental loss. The Head and Neck 215 Parotid duct (Stensen’s duct) • Traverses the midthird of a line drawn between tragus and corner of the mouth. • May be associated with injury of the facial nerve. • Untreated may result in a parotid fistula and parotitis. • Repair is facilitated by intraoral cannulation of the duct, opposite the maxillary second molar tooth. • Repaired over a stent, such as a 5Ch paediatric feeding tube, secured within the mouth during the healing period (until 3 weeks). Mandibular fractures • The mandible has areas of strength and weakness dictated by foramina, teeth and bony buttresses. • This explains why certain regions fracture more readily than others: ∘ Condyle: 36% ∘ Body: 21% ∘ Angle: 20% ∘ Parasymphysis (between the distal surfaces of the canine teeth): 14% ∘ Alveolus: 3% ∘ Ramus: 3% ∘ Coronoid process: 2% ∘ Symphysis (midline): 1% • Double fractures are common; they may occur distant from the site of trauma: ∘ Blows to the symphysis classically cause bilateral condylar or subcondylar fractures. ∘ Fractures of the body may be accompanied by contralateral subcondylar fracture. Classification Closed or open • Fractures may be open through: ∘ The skin ∘ The oral mucosa ∘ A tooth socket. Fracture pattern • Simple • Greenstick • Comminuted • Impacted. Anatomical location (Dingman and Natvig) • Symphysis • Body • Angle • Ramus 216 Chapter 3 • Condylar process • Alveolar process • Coronoid process. Favourable or unfavourable (Fry) • Classifies the direction and bevel of the fracture. • Favourable fractures oppose muscle forces. ∘ Muscle forces pull the fragments into a position favourable for healing. • Unfavourable fractures allow muscle forces to pull fragments into displacement. Presence of teeth (Kazanjian and Converse) • Knowing the status of the teeth helps plan fixation. ∘ Occlusal guidance is lost in edentulous patients. • Class I: teeth present on both sides of the fracture line. • Class II: teeth present on only one side of the fracture line. • Class III: fragments on both sides of the fracture line are edentulous. Management • The goal is to restore occlusion to its preinjury state. • Most should be treated within 48 hours of injury where possible. • Perioperative antibiotics are required due to the risk of bacterial contamination. • Early immobilisation reduces the risk of wound infection. Conservative management • This is the exception rather than the rule. • Age, dentition and compliance of the patient may preclude conservative treatment. • Involves a nonchew diet for 4–6 weeks. • Often indicated for condylar and greenstick fractures. • Also for stable, undisplaced, favourable fractures with normal occlusion. Intermaxillary fixation (IMF) • Also called mandibulomaxillary fixation (MMF). • Involves wiring teeth of the maxilla and mandible together. • Achieved by application of wires, arch bars, screws or cap splints. • IMF is used to treat severely comminuted fractures, paediatric fractures, condyle fractures and minimally displaced (favourable) fractures. • IMF usually maintained for 4–6 weeks. • Does not provide rigid fixation. ∘ Excessive movement of the fracture can lead to malunion, nonunion and osteomyelitis. • Other disadvantages include: ∘ Difficulty maintaining oral hygiene. ∘ Eating problems and weight loss. ∘ Potential airway obstruction or aspiration. – Some units give patients wire cutters in case of emergency. ∘ Persistent trismus. The Head and Neck 217 Open reduction and internal fixation (ORIF) • ORIF is the preferred method of treating most mandibular fractures. • Closed reduction using temporary IMF helps re-establish occlusion prior to ORIF. Surgical approaches • Intraoral ∘ Open ∘ Endoscopic • Extraoral ∘ Through pre-existing lacerations ∘ Submental ∘ Submandibular (Risdon) ∘ Retromandibular (transparotid or retroparotid) ∘ Preauricular ∘ Facelift. Fixation • Two basic types of fracture fixation: 1 Load bearing – Fixation bears the forces of function at the fracture site. – Usually requires larger locking reconstruction plates and bicortical screws. 2 Load sharing – Stability at the fracture site is created by a combination of friction between bone ends and the implants used for fixation. • Load sharing is not suitable where there is comminution or bone loss. – Usually accomplished with lag screws or compression plates with monocortical screws. • Champy popularised a load sharing miniplating technique: ∘ A single plate is applied along ‘ideal lines of osteosynthesis’, analogous to a tension band. • Screws should avoid the mandibular canal and tooth roots. External fixation • External fixation is rarely used but occasionally indicated for: ∘ Temporary stabilisation ∘ Extensive bony defects ∘ Osteomyelitis. Management of condylar fractures • This is controversial. • Intracapsular fractures are prone to ankylosis, particularly if immobilised. • Options for condylar fractures include: ∘ Conservative management with soft diet and physiotherapy. ∘ Closed reduction and application of IMF. – IMF with elastics rather than wires may reduce the risk of ankylosis. 218 ∘ Chapter 3 ORIF with one or two plates and screws. – Where IMF is contraindicated, e.g. epilepsy. – If adequate occlusion cannot be achieved by closed reduction. – Fracture-dislocation into the middle cranial fossa. – Lateral extracapsular fracture-dislocation of the condyle. Mandible fractures in children • Treatment depends on the child’s dental development. • Most are treatable using closed methods. • ORIF risks injury to bony growth centres and tooth buds. • Until 2 years of age: splint. • Until 4 years of age: IMF for 2–4 weeks. • Until 8 years of age: deciduous molars used for IMF. • Most children aged 9 years or older can be treated similarly to adults. • The condyle has great remodelling capacity in preteen children. ∘ IMF for 7–10 days is sufficient for condylar fractures. Zygomatic (malar) fractures • The zygoma forms: 1 Eminence of the cheek 2 Inferolateral border of orbit. • Cheek numbness affects >50% of patients with zygomatic fractures. ∘ Usually due to contusion of the infraorbital nerve. • Globe injury affects 5% of patients, mandating ophthalmology review. • The zygoma tends to fracture as a tetrapod at the following locations: 1 Zygomaticofrontal (ZF) suture 2 Greater wing of sphenoid in the lateral orbit 3 Maxilla in the orbital margin, orbital floor and anterior maxillary sinus 4 Temporal bone in the zygomatic arch. • Tetrapod fractures disarticulate the zygoma from the facial skeleton. • Enophthalmos is rare with pure tetrapod fractures. ∘ Usually indicates an associated fracture of the orbital cavity. Classification • Zingg et al. (1992), based on radiographs and CTs of 1025 patients: ∘ Type A (incomplete) – Accounts for 8% of fractures and subdivided as follows: • A1: Isolated zygomatic arch. • A2: Isolated lateral orbital rim. • A3: Isolated infraorbital rim. ∘ Type B (complete monofragment) – Accounts for 57% of fractures – the classic tetrapod. ∘ Type C (multifragment) – Accounts for 35% of fractures. • Complications of late enophthalmos and malalignment are more common with type C. The Head and Neck 219 Management Conservative • For stable undisplaced fractures. Gillies’ lift • Isolated zygomatic arch fractures are classically amenable to closed reduction using Gillies’ temporal fossa approach: 1 Incision in the temporal scalp behind the hairline. 2 Incision is deepened through superficial and deep temporal fascia onto temporalis. 3 Gillies’ elevator inserted between deep temporal fascia and temporalis. – This plane leads under the arch and avoids injury to VII. 4 The fracture is elevated; a satisfactory ‘click’ is felt on reduction. Keen’s transoral approach • The zygoma is accessed through the lateral upper buccal sulcus. • An instrument is inserted under the arch and the fracture reduced similar to Gillies’ method. ORIF • Preferred for most zygomatic fractures. ∘ Instability following attempted closed reduction necessitates ORIF. ∘ Associated orbital floor disruption also mandates ORIF. • Simple isolated fractures can be approached through one incision. • More complex and comminuted fractures require multiple incisions. Surgical approaches • Lateral canthotomy with superior cantholysis. • Transcutaneous lateral brow or upper blepharoplasty incision. • Transconjunctival preseptal approach. • Intraoral upper buccal sulcus incision. • A coronal flap gives access to the zygomatic arch in the context of severe comminution or other facial fractures. Fixation • A Carroll-Girard screw can be used as a joystick to reduce the zygoma. • The sphenozygomatic suture, due to its curvilinear shape, is a measure of the adequacy of reduction but is rarely fixed. • Miniplates (0.85 mm) are used for the load-bearing buttresses of the face: ∘ Zygomaticomaxillary (ZM) buttress and ZF suture, which withstand the pull of the masseter. • Microplates (<0.6 mm) are used on the infraorbital rim. • Type B or C tetrapod fractures typically require: 1 A miniplate to the ZF suture 2 A microplate to the infraorbital rim 3 A miniplate to the ZM buttress if there is ongoing instability. 220 Chapter 3 Maxillary fractures • The maxilla is reinforced by three vertical and three horizontal buttresses. • The vertical buttresses are: 1 Nasomaxillary buttress, along the junction of cheek and nose. 2 ZM buttress, through the body of the zygoma into the lateral orbital rim and zygomatic arch. 3 Pterygopalatine buttress, which passes posteriorly. • The horizontal buttresses are less important and pass through the: 1 Infraorbital rims 2 The zygoma 3 The alveolar arch. Le Fort fractures • René Le Fort classified maxillary fractures in 1901. • He observed the distribution of fractures in cadaveric skulls that he hit with wooden clubs and other blunt objects. • He grouped fractures of the maxilla into the following patterns. Le Fort I • Also known as Guérin’s fracture or horizontal maxillary fracture. • The fracture passes transversely through: 1 Base of the piriform aperture 2 Base of the maxillary sinus 3 Pterygoid plates posteriorly. • This fracture divides the maxilla into two segments. • The lower segment, so-called ‘floating palate’, contains: ∘ Alveolus and maxillary dentition ∘ Palate ∘ Variable amounts of the pterygoid plates. Le Fort II • Also known as a pyramidal maxillary fracture. • The fracture line passes: 1 Across the nasal bones. 2 Into the medial wall of the orbit behind the lacrimal bone. 3 Out of the orbit over the medial portion of the infraorbital rim. 4 Diagonally down and out, under the ZM buttress. 5 Through the pterygoid plates posteriorly. • The bony fragment contains: ∘ Lacrimal crests. ∘ Bulk of the maxilla with piriform margin. ∘ Alveolus and maxillary dentition. ∘ Palate. ∘ Variable amounts of the pterygoid plates. The Head and Neck Le Fort III • Also known as craniofacial dysjunction. • The fracture line passes: 1 Through the nasofrontal suture. 2 Across the orbital floor to the inferior orbital fissure. 3 Along the sphenozygomatic suture line and out through the ZF suture. 4 Through the zygomatic arch laterally and pterygoid plates posteriorly. • Results in detachment of the facial bones from the cranial base. • Patients with Le Fort injuries are often unconscious. ∘ Associated with head injury, CSF leak and significant orbital trauma. ∘ A neurosurgical and ophthalmological opinion is required. • Pure Le Fort fractures are rare and often asymmetric. ∘ Usually associated with multiple other midface fractures. • Midface fractures can also occur in a non-Le Fort pattern: ∘ Sagittal fractures of the maxilla and isolated fractures of the alveolus. ∘ Fractures of the thin maxillary wall without buttress involvement. Management • The goal of treatment is to restore preinjury facial appearance and occlusion. ∘ Achieved by restoring anterior facial projection and vertical facial height. Conservative • Reserved for undisplaced, stable Le Fort I fractures with normal occlusion. Closed reduction • May be required for emergency treatment to reduce bleeding or CSF leak. • Otherwise reserved for patients unable to have a general anaesthetic. • Following reduction, the patient is fitted with arch bars and elastic traction. • External fixation devices, such as a Levant frame, can be attached to the skull. ∘ Facial fractures can be held using percutaneous pins suspended from the frame. ORIF • This is the preferred method. • Nasotracheal intubation may not be possible, requiring tracheostomy. • Preinjury photographs of the patient can help guide treatment. Surgical approaches • Access to the fractures can be gained through the following incisions: ∘ Through extensions of existing lacerations. ∘ Upper buccal sulcus incision, giving access to: – Lower maxilla, required for all Le Fort fractures. ∘ Lower eyelid incision, usually transconjunctival, giving access to: – Orbital floor. – Infraorbital rim, required for Le Fort II and III fractures. 221 222 ∘ ∘ Chapter 3 Glabellar incision, giving limited access to: – Nasofrontal region, for some Le Fort II fractures. Coronal incision, giving access to: – Nasofrontal region. – Orbital walls. – ZF suture, zygoma and arch, required for some Le Fort II and III. Fixation • Fractures are exposed, mobilised and reduced. ∘ The maxilla requires strong mobilisation forces using various instruments: – Rowe’s disimpaction forceps. – Stromeyer hook. – Tessier retromaxillary levers. • IMF is applied, creating a maxillomandibular unit hinged on the TMJ. ∘ This is rotated superiorly until maximum bone contact occurs at the fracture site. • Plates are selected based on how unstable the fractures are: ∘ Larger plates for buttresses, which bear forces of mastication. ∘ Larger plates are also required to bridge areas of comminution. ∘ Smaller plates supplement larger plates to support comminuted fragments. • More fracture sites are plated if there is ongoing instability: ∘ Le Fort I: plates applied to each ZM buttress. – Then, if required, to each nasomaxillary buttress. ∘ Le Fort II: plates applied to each ZM buttress. – Then, if required, to each infraorbital rim. – Then, if required, to the nasofrontal suture. ∘ Le Fort III: plates applied to each lateral orbital buttress or ZF suture. – Plating of the nasofrontal suture and zygomatic arch is usually also required. • IMF is removed on completion of fixation and occlusion verified. • Bone grafting may be required for: ∘ Gaps resulting from missing bony segments. ∘ Severely comminuted fractures. Orbital fractures • Orbital fractures often occur in conjunction with: ∘ Zygomatic fractures ∘ Nasoethmoid fractures ∘ High Le Fort fractures. • There are three theories regarding the mechanism of orbital fractures: 1 Hydraulic theory – Pressure on the globe causes increased intraorbital pressure and subsequent outfracture of the orbital wall. – This is the most widely accepted theory. 2 Bone conduction theory – Pressure on the orbital rim fractures the orbital floor via buckling forces. 3 Direct globe-to-wall theory – The globe itself impacts the orbital walls causing fracture. – This is the least likely mechanism. The Head and Neck 223 • A pure orbital blowout fracture does not involve the orbital rims. • Diplopia is present in most cases but resolves within 6 months in >95% of patients. • It is important to differentiate self-limiting diplopia from diplopia that requires surgical correction: ∘ Oedema, muscle contusion or neurapraxia are self-limiting. ∘ Entrapment of inferior rectus or orbital fat requires exploration. – Entrapment can cause severe bradycardia due to the oculocardiac reflex. • The forced duction test detects true entrapment: 1 Local anaesthetic is injected into the conjunctival fornices. 2 Inferior rectus tendon is grasped with forceps through the inferior fornix, and the globe is rotated upwards. 3 Resistance to globe movement indicates mechanical restriction of movement. • The lamina papyracea of the ethmoid is the thinnest part of the orbital wall. ∘ Forms most of the medial wall. • However, the orbital floor is the most common site of a pure blowout fracture. ∘ May be because injury commonly involves the inferior orbital rim. ∘ This transmits force to the orbital floor rather than medial wall. • Blow-in fractures may result in impalement of the globe and proptosis. ∘ These usually involve the orbital roof and lateral wall. • All orbital fractures require evaluation by an ophthalmologist. Management Conservative • Most pure orbital fractures do not require surgical intervention. • Enophthalmos <2 mm is not usually noticeable. ∘ This is measured using a Hertel exophthalmometer. • Indicated for minimally displaced floor fractures with normal eye movements. • Also indicated for patients with only one seeing eye. • Needs regular follow-up to check for developing diplopia, enophthalmos or dystopia as post-traumatic oedema resolves. Surgical • Goals of surgical management are as follows: 1 Prevent or correct globe malposition. 2 Restore orthoscopic vision. 3 Maintain or improve visual acuity. • Early repair (<3 weeks) is associated with improved outcomes. • Decision to operate is based on the likelihood of developing enophthalmos or diplopia in future. • Emergency surgery may be required, e.g. for retrobulbar haematoma. Indications for surgery: enophthalmos or prevention of enophthalmos • Any acute enophthalmos. • Combined medial and inferior wall fractures. • Isolated medial wall fractures with medial displacement >3–5 mm. • Isolated orbital floor fractures with inferior displacement ≥3 mm. 224 Chapter 3 Indications for surgery: diplopia • Diplopia and a positive forced duction test. • Diplopia and depression or significant displacement of the inferior oblique muscle origin. • Acute entrapment of an extraocular muscle – can lead to avascular necrosis. Surgical approaches • The orbital floor is usually reached through various lower eyelid approaches. ∘ The aim is to reach the front of the inferior orbital rim, where dissection proceeds subperiosteally. ∘ The cornea should be protected. ∘ Important to resuspend soft tissues to the inferior orbital rim to avoid cheek ptosis. • Transcutaneous ∘ Subciliary or lower blepharoplasty ∘ Subtarsal or mideyelid ∘ Infraorbital. • Transconjunctival ∘ Inferior fornix transconjunctival (pre- or post-septal) ∘ Transcaruncular or medial transconjunctival ∘ Transconjunctival with lateral skin extension, known as a ‘swinging eyelid’. • Transoral maxillary sinus ∘ Used for endoscopic assessment of the size of fracture fragments. Reduction without fixation • In some cases, the fracture is stable following reduction and does not require fixation. • Requires close clinical follow-up. Reduction with fixation • Secure one end of a plate to the intact orbital rim and place the other end into the orbit underneath the reduced fracture, as a cantilever. Reconstruction • Most require reconstruction due to fracture comminution or bone loss. • The choice of material for orbital reconstruction is controversial: ∘ Autologous tissue – Ear or septal cartilage – Iliac crest – Anterior maxillary sinus wall – Split calvarial bone. ∘ Alloplastic material – Titanium mesh – Marlex mesh – Porous polyethylene sheets, e.g. Medpor – Resorbable materials, e.g. PDS® sheets. The Head and Neck 225 • A forced duction test must be performed after implant placement to verify that normal eye mobility has been restored. • Post-operatively, patients are monitored for retrobulbar haematoma. Nasal fractures • The nose is the most commonly fractured facial bone. • Most nasal fractures cause significant bleeding. • Intranasal examination is required to exclude septal haematoma. Classification • The AO craniomaxillofacial classification: 1 Laterally displaced fractures – Most common type. 2 Posteriorly depressed fractures – Associated with nasoethmoidal fractures. 3 Disarticulation of the upper lateral cartilage 4 Anterior nasal spine fracture – Associated with septal dislocations. Treatment • Radiological investigation is not required for isolated fractures. • Treatment is divided into early and late phases. Early phase • Acute fractures cause significant swelling, which makes reduction difficult. ∘ Closed reduction is done at 10–14 days, when swelling has reduced. • Simple fractures are treatable by closed reduction, aided by: ∘ Asch’s septum-straightening forceps ∘ Walsham’s septum-straightening forceps ∘ Boies’ nasal fracture elevator ∘ Killian’s nasal septum speculum. • The nose is packed, and an external splint applied. Late phase • Defined as the period when bony union has occurred to a degree where osteotomy is required to reduce the deformity. • This involves rhinoplasty to restore the nasal airway. Nasoorbitoethmoidal (NOE) fractures • Caused by trauma to the interorbital region. • Often occur in conjunction with other facial fractures, involving: ∘ Nose ∘ Medial wall of the orbit, including medial canthal tendon 226 Chapter 3 ∘ ∘ ∘ Ethmoids Base of the frontal sinus Floor of the anterior cranial fossa. • It is important to rule out CSF leak due to the risk of meningitis. • The nasolacrimal system should be assessed for patency. Classification • Divided into three types by Markowitz. • Can be unilateral or bilateral. ∘ Type I – A single large fragment bearing the medial canthal tendon. ∘ Type II – Comminution of the NOE area but the medial canthal tendon remains attached to a fragment of bone, allowing stabilisation with wires or a small plate. – Bilateral type II fractures may require bone grafting for dorsal nasal support. ∘ Type III – A type II but with detachment of the medial canthal tendon from the bone. – Nasal bones often require bone grafting for support. Management • Majority is managed by ORIF. • Accurate repositioning of the medial canthal tendon is crucial. Surgical approaches • A combination of approaches is usually required, including: ∘ Intraoral upper buccal sulcus incision. ∘ Extended glabellar approach, usually for type I fractures. ∘ Lower eyelid incision, usually transconjunctival. ∘ Coronal incision, usually not required for isolated type I fractures. Fixation • Type I fractures: held with a plate between the fragment and piriform aperture. ∘ If two-point fixation is required, a plate is placed at the nasofrontal suture. • Type II and III fractures usually require three-point fixation: 1 At the junction of the NOE complex and frontal bone. 2 Along the inferior orbital rim. 3 Along the piriform aperture. • Some type II and all type III fractures require a transnasal wire to reposition the medial canthal tendon. ∘ Alternatively, a bone anchor can be used. Frontal sinus fractures • The frontal sinus pneumatises at 2 years. • Size of a pea age 4 years; becomes visible on X-ray about age 8 years. The Head and Neck 227 • Continues to expand until 15–19 years. • Has a thick anterior table of bone and thin posterior table. • The nasofrontal duct, also called the frontal recess, runs from the posteromedial floor of the sinus to the middle meatus in the nose. • Most fractures are the result of high velocity trauma: ∘ 20% of patients are unconscious at presentation. ∘ 20% have CSF leaks. ∘ 75% have associated orbital, nasal or midfacial fractures. Classification • Frontal sinus fractures are classified anatomically: ∘ Anterior table fractures. ∘ Posterior table fractures. ∘ Nasofrontal duct fractures. • The following also have an impact on management: ∘ Associated dural tears. ∘ Associated fracture comminution. Management • The goals of treatment are: 1 To create a safe sinus 2 Restore facial contour 3 Avoid complications. • Treatment can require input from neurosurgeons and ophthalmologists. • Posterior table fractures have risk of CSF leak, meningitis, encephalitis, abscess and mucocele formation. • Empirical antibiotic cover is given to all for 7 days, but continued for 14 days if there is CSF leak. Observation • Suitable for minimally displaced (<2 mm) isolated anterior or posterior table fractures, not involving nasofrontal duct with no CSF leak. ∘ Some will observe CSF leaks for a week. ORIF • Suitable for displaced anterior table fractures not involving the nasofrontal duct, with risk of cosmetic deformity. • Approach through a coronal incision. • Fragments are reduced and held with thin titanium plates and screws. Obliteration • Required for comminuted fractures of the anterior ± posterior table. • Mucosal disruption can result in a nonfunctioning sinus that should be obliterated. • Fractures that interfere with the drainage system may also render the sinus nonfunctional. 228 Chapter 3 • Obliteration involves: 1 Exposure of the entire sinus by removal of the anterior table via a coronal incision. 2 Meticulous removal of all sinus mucosa, aided by burring of the bone. 3 Closing the outflow tract by packing the nasofrontal duct with fascia or bone graft. 4 Obliteration of the sinus cavity with autologous tissue. – Grafts of fascia, fat, muscle, bone or pericranial flaps. 5 Replacing the anterior table and fracture fragments with plates and screws. Cranialisation • Severe injuries involving >25% of the posterior table are considered for cranialisation. • Cranialisation is similar to obliteration but also involves: 1 Separating the dura from the posterior table with a smooth elevator. 2 Removal of the posterior table with a rongeur; the edges are smoothed with a burr. • The brain expands into the cranialised sinus. • Dural tears are repaired with neurosurgical assistance. • A pericranial flap can help achieve watertight dural closure. Frontal sinus endoscopy • With experience, this can open a damaged nasofrontal duct from below. • When successful, it obviates the need for obliteration of the sinus. • However, careful follow-up with CT scans in 6–12 weeks is essential. Panfacial fractures • These are challenging combinations of facial fractures. • Determining the ideal sequence of repair can be difficult. • The two broad options are: 1 Bottom-up – This re-establishes the maxillomandibular unit as the first major step. 2 Top-down – This starts with reduction and fixation of the calvarium. • If the mandible is used to reduce the maxilla using IMF, the mandible must first be completely reconstructed from condyle to condyle. • Fixation begins on the least comminuted side that has most reference structures intact. Oculoplastic surgery Anatomy of the eyelid • Each eyelid is arbitrarily divided into two lamellae: 1 Anterior lamella: skin and orbicularis oculi muscle. 2 Posterior lamella: tarsal plate and conjunctiva. • The grey line denotes the junction of anterior and posterior lamellae. ∘ This is visible along the middle of each eyelid margin. • The term ‘middle lamella’ is relatively new. ∘ Refers to tissues between anterior and posterior lamellae: orbital septum and preaponeurotic fat. ∘ There is no middle lamella in the region of the tarsal plates. The Head and Neck Anatomy of the eyelids Upper lid Skin Bone Fat pad Whitnall's ligament Arcus marginalis Orbicularis oculi Levator palpebrae superioris Septum Levator insertion to skin/orbicularis Levator insertion to tarsus Superior conjunctival fornix Levator aponeurosis Müller’s muscle Tarsal plate Eyelash Conjunctiva Lower lid Tarsal plate Eyelash Conjunctiva Inferior conjunctival fornix Inferior tarsal muscle Capsulopalpebral fascia Septum Arcus marginalis Orbicularis oculi Skin Inferior rectus Inferior oblique Lockwood’s ligament Bone Fat pad Asian upper lid Bone Fat pad Skin Orbicularis oculi Septum Levator palpebrae superioris Whitnall's ligament Levator aponeurosis Tarsal plate Müller’s muscle Conjunctiva Eyelash 229 230 Chapter 3 Tarsal plates • Fibroelastic sheets that maintain the structural integrity of the lids. • Contain meibomian glands. ∘ Openings of these glands mark the mucocutaneous junction, just posterior to the grey line. Orbital septum • Originates from the orbital rim as a thickening called the arcus marginalis. ∘ This is where facial and orbital periostea meet the posterior layer of the galea to form the septum. • Inserts onto the tarsus either directly (in some Asians) or via the levator aponeurosis. Orbicularis oculi muscle • Supplied from its deep surface by temporal and zygomatic branches of VII. • Orbital part for forced eye closure; palpebral part for blinking. • Palpebral part is subdivided into pretarsal and preseptal components. • These form the medial canthal tendon, which divides into two: 1 Superficial part – merges with tarsal plates and inserts anterior to the anterior lacrimal crest. 2 Deep part – inserts onto posterior lacrimal crest, posterior to the lacrimal sac. • The lateral canthal tendon arises from periosteum of the lateral orbital rim and Whitnall’s tubercle. ∘ Divides to merge with the tarsal plates. Levator palpebrae superioris muscle • Originates from the apex of the orbit near the optic canal. • Becomes aponeurotic just posterior to the septum. ∘ At this point, the muscle sheath thickens to form Whitnall’s ligament. – Attaches to the trochlear fascia medially and fascia of the lacrimal gland laterally. – Acts as a pulley, converting posterior pull into vertical movement. • The levator aponeurosis inserts into: 1 Tarsal plate. 2 Orbicularis oculi and skin. • The lower lid equivalent is the capsulopalpebral fascia. ∘ Attached to the inferior rectus muscle; depresses the lower lid in downgaze. ∘ The lower lid analogue of Whitnall’s ligament is Lockwood’s ligament. • In Caucasians, connections between levator aponeurosis and skin produce the upper eyelid fold. ∘ Usually lies along the superior border of the tarsus. • The upper eyelids of some Asians differ in the following ways: 1 The levator aponeurosis does not pass through the septum to the skin. – The lids, therefore, do not have a fold. The Head and Neck 231 2 The orbital septum is attached lower on the anterior border of the tarsal plate. – This allows the postseptal fat pads to lie anterior to the tarsal plate. • Corresponding differences can be found in the lower eyelid. Müller’s muscle • Also known as the superior tarsal muscle. • A sympathetically innervated smooth muscle elevator of the upper lid. • Arises from the undersurface of the musculoaponeurotic junction of the levator. • Inserts into the superior edge of the tarsus. • Always active, except during blinking and sleeping, providing 2–3 mm of lid lift at rest. • Its counterpart in the lower eyelid is the inferior tarsal muscle. ∘ Arises from the sheath of the inferior rectus muscle. Fat pads • Postseptal (preaponeurotic) fat pads lie between the orbital septum and levator aponeurosis. • Two fat pads in the upper eyelid: medial and central. • Three fat pads in the lower eyelid: medial, central and lateral. ∘ The lateral compartment of the upper lid is occupied by the lacrimal gland. • Part or all of the fat pads are removed during traditional blepharoplasty. • Preseptal (submuscular) fat pads lie between septum and orbicularis: ∘ Retro-orbicularis oculi fat (ROOF) pad is in the upper eyelid. ∘ Suborbicularis oculi fat (SOOF) pad is in the lower eyelid. Blood supply • Internal carotid branches anastomose with external carotid branches via: ∘ Facial artery and angular artery at the medial canthus. ∘ Superficial temporal artery at the lateral canthus. ∘ Infraorbital artery at the lower eyelid. • Medially, the ophthalmic artery gives superior and inferior marginal arteries. ∘ Pass laterally on the anterior tarsus as the marginal arcades. • Laterally, the lacrimal artery gives a lateral palpebral artery to each lid. ∘ Course medially to anastomose with the marginal arcades. The lacrimal system Secretory function • Basic secretors provide lid lubrication in three layers: 1 Mucin-secreting goblet cells produce the innermost mucoprotein layer. 2 Accessory lacrimal glands produce an intermediate aqueous layer. 3 Meibomian glands in the tarsus, and the glands of Zeis and Moll at the root of the eyelashes, produce the outermost oily layer that increases tear evaporation time. 232 Chapter 3 • The lacrimal gland proper is a reflex secretor, producing fluid similar to the intermediate tear layer. ∘ Reflex secretors respond to sudden changes in the physical or emotional environment. Drainage function • At the apices of the lacrimal papillae, the upper and lower puncta drain into the canaliculi. • The canaliculi have a 2 mm vertical part and 8 mm horizontal part. ∘ They dilate to form the ampulla at the junction of vertical and horizontal parts. • The horizontal parts of each canaliculus join to form the common canaliculus. • This empties into the lacrimal sac. ∘ The sac is surrounded by the ‘lacrimal pump’ – fibres of the orbicularis oculi. • The sac empties into the bony opening of the nasolacrimal duct. • The nasolacrimal duct empties into the inferior meatus of the nose. Eyelid reconstruction • The aim is protection of the globe with: ∘ Stable skin ∘ Lid support ∘ Lining ∘ Function (a dynamic lid). • Defects of anterior and posterior lamella require separate reconstruction. • Defects of skin alone require thin full thickness skin grafts. • Wounds that cross the eyelid margin require reconstruction of both lamellae. • The upper lid contributes most to eyelid closure. • The lower lid contributes most to passive corneal coverage. • The adage that the lower eyelid is used to reconstruct the upper, but the upper is not used for the lower is not a universally held view. • Skin should never be used to replace conjunctiva. ∘ Surface keratinisation and lanugo hairs irritate the eye. • Flaps are planned so any tension is oriented parallel to the lid margin. • When estimating tissue requirements for posterior lamella reconstruction, gently pull the wound edges towards each other to eliminate horizontal lid laxity. • Posterior lamella grafts must be secured to tarsal plate or canthal tendon at the defect margins. ∘ If neither is available, the graft is sutured to periosteum. Lower eyelid Defects less than 1∕3 of the horizontal width • Lesions are excised as a pentagon to produce a square-edged tarsal defect. • Layered closure with perfect alignment of the tarsus. • The eyelid margin is realigned with a suture through the grey line or lash line. • Dog-ear excision is tapered laterally to minimise risk of ectropion. • If there is excessive tension, lateral cantholysis may be required. • Larger defects can be closed in elderly patients due to greater tissue laxity. The Head and Neck 233 Pentagonal excision Larger excision with dog ear Defects between 1∕3 and 2∕3 of the horizontal width • Pentagonal excision as previously mentioned. • Lateral cantholysis mobilises the lower lid to allow direct closure. ∘ Usually provides an additional 5 mm of advancement. ∘ Involves division of the lower limb of the lateral canthal tendon: – Lateral canthotomy for access to the lateral canthal tendon. – Medial traction is applied to the lateral part of the lower lid. • The lower limb of the lateral canthal tendon can now be felt as a tight band. – The lower limb is dissected by spreading scissors along its edges. – It is divided, allowing the lower eyelid to advance medially. • Tenzel’s semicircular musculocutaneous rotation flap can be used if lateral cantholysis alone is insufficient to allow direct closure. ∘ The posterior lamella can be reconstructed with a periosteal flap hinged on the lateral orbital margin. Lateral canthotomy Lateral cantholysis Tenzel flap Limit to lateral eyebrow 234 Chapter 3 Defects greater than 2∕3 of the horizontal width • Modified Hughes tarsoconjunctival flap from the upper lid can reconstruct a shallow posterior lamella defect: ∘ Evert the upper lid and incise horizontally through conjunctiva and tarsus ≥4 mm superior to the eyelid margin. – The width of the incision is just narrower than that of the lower lid defect. ∘ Vertical incisions extend superiorly from the ends of the horizontal incision to allow the flap to reach the lower eyelid defect. • The Hughes flap is covered with a local flap or skin graft for the anterior lamella. • The flap can be divided at 10 days, but many delay division for 3 weeks. • Alternatively, tarsoconjunctival graft from the opposite eyelid, or chondromucosal graft from nasal septum, can be used for very large defects. ∘ Grafts need vascularised cover with a flap for the anterior lamella. ∘ Examples include cheek rotation–advancement flaps (Mustardé or McGregor). Hughes tarsoconjunctival flap Everted upper lid Conjunctiva Flap of tarsus Mustardé cheek rotation flap McGregor cheek flap The Head and Neck 235 Alternatives for the anterior lamella • Bipedicled Tripier flap from the upper lid. • Superiorly based nasojugal flaps. • Glabella flaps for defects around the medial canthus. • Fricke temporal brow flap and paramedian forehead flap. Alternatives for the posterior lamella • Auricular cartilage grafts. • Oral mucosal grafts from hard palate or buccal mucosa. • Acellular dermal matrix. • Tarsomarginal grafts from an intact eyelid. • Hewes tarsal transposition flap, for defects extending to the lateral canthus. Hewes tarsal transposition flap Flap of tarsal plate and conjunctiva Donor site closed directly (Müller’s to tarsus) Posterior lamella flap in place Upper eyelid Defects less than 1∕3 of the horizontal width • Reconstructed by direct closure, similar to the lower eyelid. Defects between 1∕3 and 2∕3 of the horizontal width • Lateral canthotomy and cantholysis may allow direct closure. • A Tenzel or McGregor flap gives more advancement if required. • Larger defects: sliding upper eyelid tarsoconjunctival flap for posterior lamella, covered by local flap or full thickness skin graft. Upper eyelid Tenzel flap Limit to lateral eyebrow 236 Chapter 3 Defects greater than 2∕3 of the horizontal width • Cutler-Beard flap for central defects: ∘ Inferiorly based flap containing all layers of the lower eyelid. ∘ Apex is 5 mm inferior and parallel to the lower lid margin. ∘ Sides of the flap run down towards the inferior orbital rim. ∘ Flap is advanced into the defect under a bridge of intact lower lid. ∘ Sutured into position to lie across the globe for 6 weeks. ∘ The flap is divided as a second procedure. ∘ The base of the pedicle is then inset into the lower lid donor site. Cutler-Beard flap Full thickness incision 5mm bridge Alternative reconstructions • Mustardé lower lid switch flap. ∘ Donor site is reconstructed by one of the techniques outlined previously. ∘ The lid switch flap is divided at a second procedure. • Orbicularis myocutaneous advancement flap. ∘ Large V-Y advancement from the upper eyelid. ∘ Can be used for large anterior lamella defects. • Other regional flaps: ∘ Nasal chondromucosal flap based on the dorsal nasal artery. ∘ Cutaneous flaps based on branches of the superficial temporal artery. Mustardé lid switch Secondary defect Pedicle divided The Head and Neck 237 Ptosis • Ptosis (or blepharoptosis) is drooping of the upper eyelid. • Contraction of the levator elevates the lid. ∘ Normal upper lid excursion is 12–15 mm. ∘ Müller’s muscle adds 1–2 mm of elevation. • In primary gaze, the upper eyelid covers 1–3 mm of the upper cornea. ∘ True ptosis is defined as drooping below this normal position. • It should be differentiated from: 1 Pseudoptosis – Apparent ptosis unrelated to deficiency of eyelid elevation. • Microphthalmos and enophthalmos. • Loose skin that overhangs the lid margin. • Lid retraction or proptosis of one eye giving the appearance of ptosis in the other. 2 Blepharophimosis – Autosomal dominant condition characterised by congenital small palpebral fissures due to: • Ptosis • Epicanthal folds (epicanthus inversus) • Telecanthus. 3 Blepharochalasis – Rare syndrome of unknown aetiology; occurs in young adults. – Recurrent bouts of upper eyelid oedema. – Results in excess eyelid skin and laxity of supporting structures. Classification • ‘MMAN’: • Myogenic: ∘ Congenital levator dystrophy ∘ Myasthenia gravis ∘ Blepharophimosis syndrome ∘ Progressive external ophthalmoplegia. • Mechanical: ∘ Dermatochalasis ∘ Tumour ∘ Scar ∘ Anophthalmos. • Aponeurotic: ∘ Congenital or acquired defects in the levator mechanism. 238 Chapter 3 • Neurogenic: ∘ Third nerve palsy ∘ Marcus Gunn jaw-winking – Peculiar congenital cause of ptosis – Synkinetic winking on movement of the jaw. ∘ Aberrant regeneration of the third nerve ∘ Horner’s syndrome: 1 Ptosis 2 Miosis 3 Anhidrosis 4 Apparent enophthalmos. • Lack of sympathetic innervation to Müller’s and inferior tarsal muscles narrows the palpebral fissure, causing apparent enophthalmos. Assessment • Establish the cause: not all ptosis requires surgery, e.g. myasthenia. • History: duration and progression, precipitating events and family history. • Examination: fundi, visual acuity, pupil reaction and range of eye movements. • Evaluate Bell’s phenomenon, corneal sensation, tear break-up time and Schirmer’s filter paper test. ∘ Deficiency increases risk of post-operative discomfort, corneal damage and visual impairment. • Bell’s phenomenon is assessed by holding the upper lid open as the patient attempts gentle closure of the eye. ∘ Upward movement of the eye confirms the presence of Bell’s phenomenon. • Schirmer’s test quantifies tear production and involves the following: ∘ The conjunctiva is anaesthetised with topical drops. ∘ A 35 mm × 5 mm strip of filter paper is placed at the junction of the middle and lateral thirds of both lower lids. ∘ Excursion of tears along the paper is measured after 5 minutes. ∘ 10 mm or more is normal; less than 5 mm indicates tear deficiency. • Tear break-up time assesses the quality of the tear film. ∘ Fluorescein is instilled into the eye. ∘ The cornea is visualised with cobalt blue light. ∘ The tear film should remain intact for about 20 seconds. • Examination should also include the following specific tests for ptosis: Margin-reflex distance • Documents the relative positions of all four eyelids. • The patient looks at a point light source about 50 cm away. • Distance between the corneal light reflex and each lid margin is measured using a narrow ruler held vertically against the medial eyebrow. Levator function • Brow position is fixed with a thumb to eliminate compensation by frontalis. The Head and Neck 239 • A ruler, held against the medial eyebrow, measures excursion of the upper lid between upgaze and downgaze. • Levator dehiscence produces a higher skin crease with a deep upper lid sulcus. Jaw-winking • Voluntary movement of the jaw side-to-side, or wide mouth opening, will elevate the eyelid if jaw-winking is present. Fatigue • Seen in myasthenia gravis. • The patient is asked to look up for 30 seconds without blinking. • Upper lids will droop if fatigue is present. Phenylephrine test • Used in patients with minimal ptosis <2 mm. • 10% phenylephrine is instilled into the affected eye; 2.5% can be used if there is a cardiac history. • Phenylephrine is an α1-adrenergic agonist that stimulates Müller’s muscle. • The margin-reflex distance is reassessed after 5 minutes. • Restoration of normal lid position indicates suitability for Müller’s muscle shortening. Surgical correction • The correct choice of operation is determined by: ∘ Levator function. ∘ The degree of ptosis. • Recommended operations are as follows: ∘ Levator function >10 mm with ptosis ≤2 mm: Müller’s muscle shortening. ∘ Levator function >10 mm with ptosis <4 mm: levator aponeurosis repair. ∘ Levator function >4 mm with any degree of ptosis: levator resection. ∘ Levator function <4 mm: brow suspension. Müller’s muscle shortening • The Fasanella-Servat tarso-Müllerectomy removes conjunctiva, Müller’s muscle and superior third of the tarsal plate: ∘ Evert upper lid and apply artery forceps close to the superior border of the tarsus. ∘ Place a row of sutures through conjunctiva, Müller’s and tarsus just proximal to the clip. ∘ Remove the clip and excise tissue distal to the line of sutures. ∘ Run a second continuous suture over the cut edge and bury all knots. Levator aponeurosis repair • Can be done under local anaesthetic, allowing dynamic assessment of the correction. ∘ Either anterior approach: incision at the level of a normal upper lid skin crease. ∘ Or posterior approach: transconjunctival incision of the upper eyelid. • Suture through tarsal plate into healthy aponeurosis. • Excise excess levator tissue and skin prior to closure (anterior approach). 240 Chapter 3 ∘ Incorporate a bite of levator aponeurosis to recreate the skin crease. • For the posterior approach, suture ends come through the lid to emerge along the skin crease. ∘ Tie sutures over a bolster after the tension has been set. Levator resection • Also done through an anterior or posterior approach. • Beard described an algorithm for levator resection in congenital ptosis. • Resection varies from 10 to >23 mm, depending on levator function and degree of ptosis. Brow suspension • Depends on the action of frontalis for efficacy. • Crawford’s method is used from the age of 4 years: ∘ A strip of fascia lata is inserted transversely, just above the upper lid margin. ∘ Tunnelled upwards, deep to orbicularis and within frontalis, using a Wright needle. ∘ The ends are brought out at the brow, tightened, tied and buried. • Fox’s method is used in children younger than 4 years. ∘ Synthetic material, such as a silicone rod, is used to avoid harvesting fascia. Ectropion • • • • Ectropion is eversion of the eyelid margin away from the globe. More common in the lower eyelid. Exposure of the globe and conjunctiva results in a dry eye with reflex tear production. Leads to epiphora, punctum stenosis and secondary cicatricial changes in the skin. ∘ Ectropion progressively worsens in a vicious circle of scarring. Classification • ‘PICM’: ∘ Paralytic ∘ Involutional ∘ Cicatricial ∘ Mechanical. Assessment • Mechanical causes, e.g. eyelid tumour. • Facial nerve weakness. • Cicatricial skin changes. ∘ Ask the patient to look up while opening the mouth. • Assess horizontal lid laxity by gently pulling the lid away from the eye. ∘ A gap >10 mm between cornea and posterior lid margin is abnormal. • Pull the lid downwards and observe ‘snap-back’ to normal position. ∘ Immediate snap-back is normal. ∘ Severe laxity may require a blink or push from a finger to return the lid. The Head and Neck 241 • Assess canthal tendons by pulling the lower lid laterally, then medially: ∘ The punctum lies just lateral to the caruncle and moves laterally <1–2 mm. ∘ The lateral canthus lies 1–2 mm medial to lateral orbital rim and moves medially <1–2 mm. ∘ Rounding of the acute angle of the lateral canthus is a sign of lateral tendon laxity. Surgical correction Paralytic ectropion • The medial aspect is addressed first. • Medial canthoplasty is done if the medial canthal tendon is intact. ∘ An unstable medial canthus requires medial canthopexy ± medial wedge excision. • Any remaining ectropion requires lid tightening with a lateral canthal sling or KuhntSzymanowski. Involutional ectropion • Caused by horizontal laxity of the eyelid. ∘ Most procedures therefore involve horizontal shortening. • Choice depends on the site of maximum laxity and stability of canthal tendons: ∘ Medial laxity and stable medial canthus: medial wedge (pentagon) excision. ∘ Medial laxity but unstable medial canthus: medial canthopexy ± medial wedge. ∘ Lateral laxity and stable lateral canthus: lateral wedge. – If there is also excess skin: Kuhnt-Szymanowski. ∘ Lateral laxity but unstable lateral canthus: lateral canthal sling. Kuhnt-Szymanowski procedure • This technique combines: ∘ Wedge resection of the lateral posterior lamella ∘ Subciliary blepharoplasty incision with excision of excess skin. Lateral canthal sling (or lateral tarsal strip) • Tightens the lower lid. • Lower limb of the lateral canthal tendon is dissected through a lateral canthotomy. • Adjacent tarsal plate is denuded of soft tissue, creating a ‘strip’ of tarsus. • This is secured to lateral orbital rim, 2–3 mm above the level of the medial canthus. ∘ Usually requires release of the septum from the inferolateral orbital rim. Cicatricial ectropion • Generalised: release tethering structures and graft or flap. • Linear: Z-plasties to lengthen the scar. Entropion • Entropion is inward rotation of the eyelid margin and eyelashes towards the globe. • The lower eyelid is most commonly affected. • Entropion traumatises the globe, resulting in pain and corneal scarring. 242 Chapter 3 Classification • ‘CIC’: ∘ Cicatricial ∘ Involutional ∘ Congenital. Assessment • Cicatricial entropion is due to contracture of the posterior lamella. ∘ May cause difficulty everting the eyelid during examination. – In contrast, everting the lid in involutional entropion is easy. • Involutional entropion occurs when preseptal orbicularis displaces over the pretarsal orbicularis. ∘ Usually occurs during blinking and lid closure. • Congenital entropion is rare; usually caused by dysgenesis of the eyelid retractors. ∘ It should be distinguished from epiblepharon, although the two may coexist: ∘ Epiblepharon is when pretarsal orbicularis and skin override the eyelid margin. – This pushes the eyelashes vertically upward, but lid position is normal. ∘ In congenital entropion, eyelashes turn inward due to rotation of the lid margin. Surgical correction • Cicatricial entropion is caused by vertical deficiency of the posterior lamella. ∘ Treated by releasing the scar and grafting the resultant defect. ∘ Other options include transverse fracture and eversion of the tarsal plate or everting wedge excisions of the tarsus. • Involutional entropion can be treated by: ∘ Simple everting sutures. ∘ Quickert’s procedure – Corrects horizontal lid laxity, attenuation of lid retractors and overriding orbicularis in one sitting – It is therefore the preferred procedure. • Congenital entropion is usually repaired by excising a strip of skin and muscle. ∘ The lid retractors may have to be advanced to the tarsal plate. ∘ During closure the skin crease is fixed to the tarsal plate. Other oculoplastic conditions and procedures Trichiasis • Common acquired condition – normal eyelashes are directed inwards towards the globe. • Often associated with entropion. Distichiasis • Rare congenital condition – an additional abnormal row of eyelashes arises from the meibomian gland orifices. The Head and Neck 243 Symblepharon • Adhesion between palpebral conjunctiva of the eyelid and bulbar conjunctiva of the globe. • Causes include chemical burns and Stevens–Johnson syndrome. Epicanthic folds • Prominent vertical skin folds overlying the medial canthus, affecting: ∘ Patients with blepharophimosis. ∘ Some patients with Down’s syndrome. ∘ Some people of Asian descent. • Can be released with a Mustardé jumping man flap. ∘ The ‘legs’ of this flap should extend laterally onto the eyelids. Temporary central tarsorrhaphy sutures • Protect the cornea when there is scleral show following trauma or surgery. • Disadvantage: they close the eye and obstruct vision. • 4/0 suture brings the eyelids together as follows: ∘ The suture enters the upper lid, 2 mm from the lash line. ∘ Passes through the grey line of each lid. ∘ Exits at a symmetrical point on the lower lid. ∘ Repeated in the opposite direction, akin to a horizontal mattress suture. ∘ Tarsorrhaphy tubing prevents the suture from cutting through the skin. Temporary lateral tarsorrhaphy sutures • The length of palpebral fissure to be closed is prepared by excising a 1 mm rim of tissue just posterior to the grey line. • Sutures are passed through the skin and cut edges, similar to the central tarsorrhaphy technique. Lid traction sutures • Commonly known as Frost sutures. • Used to protect the cornea beneath dressings: ∘ A suture is passed through the grey line onto skin, 2–3 mm from the lash line. ∘ Tarsorrhaphy tubing is place over the needle and the suture passed back through the skin and grey line. ∘ Alternatively, pass the suture in and out of the grey line without going through skin. ∘ The free ends of suture can be taped onto the brow to elevate the lower lid or onto the cheek to lower the upper lid. Evisceration • Removal of cornea and contents of the globe, leaving sclera intact. • The optic nerve is separated from the back of the sclera. • An implant is placed inside the globe. • Sclera, Tenon’s capsule and conjunctiva are closed in layers. 244 Chapter 3 • A prosthesis is placed on top of the globe at a later date. • Small risk of sympathetic ophthalmitis in the other eye. Enucleation • Removal of the globe, leaving soft tissues of the orbit intact. • Extraocular muscles may be sutured to an implant to maintain their function. Exenteration • Complete removal of the contents of the orbit, including eyelids. • Performed by dissection in a subperiosteal plane. • The defect can be left to heal by secondary intention – can take 3 months. ∘ Skin grafting results in a deeper socket by minimising granulation tissue formation. • Free or pedicled flaps can be used to obturate the defect. Facial palsy Anatomy of the facial nerve Intracranial • Two distinct roots: 1 The facial nerve proper, from about 7000 facial motor nuclei. 2 Nervus intermedius, from about 3000 sensory and visceral efferent nuclei. • No predictable topographic fascicular organisation. • Emerges from the medullopontine angle of the brain stem to enter the petrous temporal bone at the internal auditory meatus alongside VIII. Intratemporal • Intratemporal branches: 1 Greater petrosal nerve – From the geniculate ganglion; contains taste and parasympathetic fibres. – Secretomotor to the lacrimal gland and mucosal glands of the nose and palate. – Conveys taste fibres from the soft palate. 2 Nerve to stapedius 3 Chorda tympani – Leaves the middle ear through the petrotympanic fissure. – Supplies taste to the anterior 2∕3 of the tongue, via the lingual nerve. – Also parasympathetic secretomotor fibres to submandibular and sublingual glands, via the submandibular ganglion. Extratemporal • Exits the stylomastoid foramen to become extratemporal. • Injuries distal to the stylomastoid foramen cause facial paralysis only. The Head and Neck 245 • More proximal injuries also cause: ∘ Loss of taste (ageusia) in the anterior 2∕3 of the tongue (chorda tympani). ∘ Hyperacusia (nerve to stapedius). • The first extratemporal branch is the posterior auricular nerve. ∘ Supplies occipitalis and posterior auricular muscles. • The next branch supplies posterior belly of digastric and stylohyoid. • The nerve then enters the parotid to divide into: 1 An upper temporozygomatic trunk. 2 A lower cervicofacial trunk. • Within the parotid, trunks divide and rejoin, resulting in five terminal divisions. ∘ There is extensive variability, cross-innervation and functional overlap. 1 Temporal or frontal branch ∘ Travels along Pitanguy’s line, from 0.5 cm below the tragus to 1.5 cm above the lateral end of the eyebrow. – This is a guideline only – there is extensive variability. ∘ Lower motor neuron lesions paralyse the ipsilateral frontalis muscle. ∘ Upper motor neuron lesions preserve frontalis, due to dual cortical representation of the forehead. 2 Zygomatic branch ∘ Supplies orbicularis oculi and upper lip elevators. 3 Buccal branch ∘ Travels alongside the parotid duct. ∘ Branches supply buccinator and upper lip muscles. 4 Marginal mandibular branch ∘ Lies just below the mandible, deep to platysma and superficial to facial vessels. – However, its location is variable. ∘ Supplies lower lip muscles. ∘ Division results in elevation of the corner of the mouth. 5 Cervical branch ∘ Supplies platysma. Congenital aetiologies Trauma • The most common cause of unilateral congenital palsy is birth trauma. • Risk factors include: ∘ Forceps delivery ∘ High birthweight ∘ Primiparity. • Neurapraxia is usual – complete transection is rare. Developmental • Causes include syndromes and teratogens. 246 Chapter 3 Möbius syndrome • Rare; typically involves bilateral paralysis of VI and VII. ∘ Cranial nerves III, IV, V, IX, X and XII may also be involved. • Patients have expressionless ‘mask-like’ facies and difficulty feeding. • Intelligence is usually normal. • Autistic symptoms reported in 30–40% of cases. • Musculoskeletal abnormalities affect 25%; the most common is talipes equinovarus. • Poland’s syndrome affects 15%. • Most are sporadic, but a minority appears to have a genetic basis. Hemifacial microsomia • Discussed in detail in ‘Craniofacial surgery > Atrophy/hypoplasia’. • Sensorineural hearing loss and facial palsy occur in up to 25% of cases. The CHARGE association • Involves VII in up to 1∕3 of cases. Acquired aetiologies • Classified by the sites at which they occur: Central causes • Tumours • Multiple sclerosis • Polio. Intratemporal causes • Bell’s palsy • Trauma • Otitis media • Cholesteatoma • Acoustic neuroma • Herpes zoster oticus (Ramsay Hunt syndrome) • Lyme disease. Extratemporal causes • Trauma • Parotid malignancy • Iatrogenic injury. Bell’s palsy • Named after Sir Charles Bell, following his case reports from the 1820s. ∘ Originally, it referred to facial nerve paralysis from any cause. ∘ Today, the term refers to idiopathic facial nerve paralysis. • It is the most common ‘cause’ of unilateral facial palsy – 55% of cases. • Mean age of onset is 40–44 years; equal sex distribution. The Head and Neck 247 • 31% have incomplete paralysis; 69% have total paralysis. • Bell’s palsy is a diagnosis of exclusion. ∘ Theories implicate herpes simplex virus causing nerve swelling. ∘ VII’s tight intratemporal course may predispose it to ischaemia when swollen. Clinical features • Typical history is acute onset facial palsy, unilateral in >99% of cases. • Most report a viral prodrome. • Common associated symptoms include pain and taste disturbance. • Lacrimal dysfunction is rare. Treatment and prognosis • Level 1 evidence shows benefit from 60 mg/day of prednisolone, started within 72 hours of onset. ∘ There is no benefit to antiviral drugs. • Most patients recover full facial nerve function. ∘ In cases of facial paresis (incomplete paralysis), 94% recover completely. ∘ In cases of total paralysis, prognosis is as follows: – 71% recover normal facial nerve function. – 13% have insignificant sequelae of incomplete recovery. – 16% have permanent and significant facial nerve dysfunction. • 6–9% of all cases will go on to develop recurrent Bell’s palsy. • Those who recover completely usually show some return of facial movement within 3 weeks, consistent with neurapraxia. ∘ Complete recovery usually takes 6–12 weeks. • In severe cases, complete axonal degeneration occurs. ∘ Recovery usually begins after 3 months and is incomplete. Iatrogenic injury • The most common site is the parotid. • May be mechanical injury from a blade or thermal injury from drilling bone. • Most cases are not detected intraoperatively. • Exploration of the nerve is indicated if paralysis persists beyond the duration of action of any local anaesthetics used, and the integrity of the facial nerve was not confirmed at the index operation. Herpes zoster oticus • Also known as Ramsay Hunt syndrome. • Responsible for approximately 10% of unilateral facial palsy. • Caused by reactivation of latent herpes zoster virus within the geniculate ganglion. • Characterised by facial palsy with vesicular lesions in the external acoustic meatus. • There is severe otalgia and other cranial nerves may be involved, particularly VIII. • Carries a worse prognosis than Bell’s palsy: ∘ 50% of patients with complete palsy fail to recover. • Prednisolone with aciclovir is beneficial if started within 72 hours of onset. 248 Chapter 3 Melkersson-Rosenthal syndrome • A chronic granulomatous condition characterised by: ∘ Recurrent facial palsy. ∘ Chronic facial oedema. ∘ Fissured tongue. • Surgery is generally unsuccessful – patients are best managed by a rheumatologist. Grading • House and Brackmann defined a system that evaluates gross appearance, symmetry and tone at rest, motion of the forehead, eye and mouth. ∘ Grade I: normal ∘ Grade II: mild dysfunction ∘ Grade III: moderate dysfunction ∘ Grade IV: moderately severe dysfunction ∘ Grade V: severe dysfunction ∘ Grade VI: total paralysis. • Their study defines each grade in detail and provides a scoring system for movement. • It is criticised for not being able to detect significant changes in facial function. ∘ However, it was not designed for this purpose. • The Sunnybrook Facial Grading System is regarded as more sensitive, easier to use, with better interobserver reliability. • Nevertheless, the House Brackmann scale remains the gold standard. Assessment Asymmetry, both static and dynamic. Scars or signs of previous trauma. Absence of forehead wrinkles. Position and movement of the upper eyelid. Evidence of conjunctival exposure. Ectropion of the lower eyelid. Position of the mouth. The smile. Any synkinesis. It is important to: ∘ Test the strength of eyelid closure. ∘ Perform the lower eyelid snap test. ∘ Assess whether the patient has any nasal valving. ∘ Verify temporalis function – can be used for reanimation. ∘ Analyse the smile on the normal side to plan vectors of slings or muscles. – Rubin classifies the smile as follows: • A: The ‘Mona Lisa’ smile. • B: The ‘canine’ smile. • C: The ‘full denture’ smile. • Standardised photography and videography are useful adjuncts. • • • • • • • • • • The Head and Neck 249 Special tests • Help localise the site of the facial nerve lesion: ∘ Schirmer’s test for integrity of the greater petrosal nerve. ∘ Taste to the anterior 2∕3 of tongue. ∘ Stapedius reflex test. Imaging • CT and MRI have largely superseded stapedius reflex tests. • CT assesses bone; MRI assesses soft tissues, pontomedullary angle and parotid. Electrophysiology • Electroneuronography (ENoG) is the most accurate electrophysiological test for determining prognosis during early stages of Bell’s palsy. ∘ Also called evoked electromyography (EEMG). • Measures compound action potential of facial muscles near the nasolabial fold during transcutaneous stimulation of VII at the stylomastoid foramen or zygomatic arch. • Performed after 72 hours of symptom onset, once Wallerian degeneration has taken place. • Degree of axonal degeneration is proportional to the reduction in amplitude of the compound action potentials. ∘ This is expressed as a proportion of the normal side’s amplitudes. – Less than 90% degeneration is associated with 80–100% recovery rates. – Of those with more than 90% degeneration, 50% will not recover function. • ENoG can be repeated at 3–5 day intervals to establish a trend. ∘ Can help decide which patients might benefit from early nerve decompression. • Less useful after 21 days due to the combination of degeneration and regeneration that may be occurring. • ENoG should not be confused with electroneurography – a generic term for nerve conduction studies. ∘ It is also different from standard electromyography, which measures spontaneous and voluntary muscle activity. Management 1 Nonoperative. 2 Operative. ∘ Static procedures. ∘ Dynamic procedures. Nonoperative treatment Eye protection • Protection of the eye preserves the patient’s sight. ∘ Regular eye drops. ∘ Punctal plugs to prevent tear drainage. ∘ Wearing glasses. ∘ Taping the eyelids closed at night. • Paralytic ectropion may be helped by horizontal taping of the lower lid. 250 Chapter 3 Botulinum toxin • Injection into the normal side can improve facial symmetry. ∘ Used to paralyse the normal lower lip depressors and forehead. • Can be used to create eyelid ptosis to protect an at-risk cornea. • Also used for synkinesis and crocodile tears. ∘ Injecting toxin into the lacrimal gland has a risk of diplopia. Fillers • Asymmetry of the cheeks and nasolabial folds can be improved with fillers. Physiotherapy • Telling the patient to ‘try to move as much as you can’ is counterproductive. ∘ Induces frustration and strengthens the normal side, worsening asymmetry. • Neuromuscular retraining by specialist therapists can be beneficial for patients with partial paralysis. • Biofeedback exercises can help. • Use of electrical stimulation to improve recovery is controversial. Operative treatment – static procedures • Indicated in the following circumstances: ∘ Corneal protection. ∘ Persisting asymmetry following partial nerve recovery. ∘ Specific functional problems, such as nasal valving or oral incompetence. ∘ Inability to tolerate a prolonged procedure under general anaesthetic. ∘ Head and neck cancer with poor prognosis. ∘ Failure of dynamic reconstructions. • Treatments for paralytic ectropion are discussed in ‘Oculoplastic surgery > Ectropion’. Temporary tarsorrhaphy • Narrows the palpebral fissure by joining part of the eyelids to one another. ∘ Narrowing the palpebral fissure aids eye closure and protects the cornea. • Done when there is still some expectation of recovery. Permanent lateral tarsorrhaphy • Permanent lateral tarsorrhaphy is not usually recommended: ∘ Narrows the temporal visual field. ∘ Cosmetically unattractive because it reverses the normal palpebral slant. Medial canthoplasty • This is preferred over a permanent lateral tarsorrhaphy. Insertion of gold weights or springs • Inserted into the upper eyelid to help eye closure. • Sutured to the anterior surface of the tarsal plate. • Aim to achieve ptosis at rest and complete closure on blinking. The Head and Neck 251 • They are less effective when supine due to the action of gravity. Brow lifts • Brow lifts can be performed by: ∘ Direct excision of skin just above the brows. ∘ Suspension of the brow through a coronal or endoscopic approach. • The greatest amount of lift is achieved using the direct approach. • The supraorbital and supratrochlear sensory nerves are at risk. • Alternatives include midforehead and pretrichial brow lifts. • Brow lift has the potential to cause lagophthalmos. Static slings • Fascia or tendon grafts can be used to elevate the corner of the mouth and nasal ala. • Use of barbed threads has also been described, with variable results. • The aim is to achieve symmetry at rest. Nasal alar batten grafts • Cartilage grafts are placed deep or caudal to the lateral crus of the lower lateral cartilage. • They strengthen and lateralise the ala to minimise collapse (valving) during inspiration. Lower lip wedge resection • Can assist with oral competence. Operative treatment – dynamic procedures • The aims of dynamic reconstruction are to restore: ∘ Voluntary movement, especially the smile. ∘ Facial symmetry. ∘ Resting tone. • Trophic status of the facial muscles is key to management: ∘ Reinnervation must occur within 2 years to avoid chronic changes of denervation. ∘ Neuromuscular fibrosis and atrophy of the muscles make it impossible to achieve useful movement after this time, even if reinnervation is achieved. • Procedures should therefore be completed within 18 months to allow time for the nerve to reach its targets. • Beyond this time, new muscle must be imported. Primary nerve repair • Microsurgical repair can be done for damaged or cut nerves. • In optimal conditions, it is associated with good recovery of function. Primary nerve autografting • Done following nerve resection during tumour removal. • Grafts of the cervical plexus, e.g. great auricular nerve, or sural nerve are used to bridge the defect. 252 Chapter 3 • Approximately 75% of patients have ‘good’ results, defined as House Brackmann III or better. Reinnervation or nerve substitution • Re-establishes input to distal facial nerve stumps using donors other than native VII. • Useful when the proximal stump of VII is not available. Hypoglossal (XII) to facial (VII) nerve transfer • XII–VII transfer is used due to its proximity to the extratemporal facial nerve. • XII is divided distally and reflected up to VII. • Achieves good resting tone in >90% of patients. ∘ However, many patients only achieve mass facial movement. ∘ Severe tongue dysfunction may affect 25% of patients. • Rather than transecting the whole nerve, Viterbo described a jump graft between XII and VII. ∘ Involves end-to-side coaptation of a nerve graft to XII. ∘ The other end of the graft is sutured to distal stumps of VII. VII–VII cross facial nerve grafting (CFNG) • First described by Scaramella in the 1970s. • A reversed sural nerve graft is coapted to a branch of VII on the unaffected side of the face. ∘ The precise donor branch is selected after mapping the function of each branch of VII. – This is necessary due to the extensive variability and branching seen. ∘ A branch is selected that produces pure smile without eye closure or grimacing. ∘ The graft is then coapted to the distal stumps of VII on the affected side of the face. • CFNG can be performed as a one- or two-stage procedure. • The two-stage procedure involves: 1 Securing the distal end of the CFNG to the tragus. – This aids its future identification. – Growth of axons is assessed by an advancing Tinel’s sign. – Usually takes 6–12 months. 2 The end of the graft is found on the paralysed side and the terminal neuroma resected. – The graft is sutured to the distal stump(s) of the facial nerve. • The advantage of using VII as a donor is its mimetic input. ∘ Allows spontaneous involuntary blink and smile. • Disadvantages are a long nerve graft and potential for weakness on the normal side. • Despite initial enthusiasm, CFNG has enjoyed only limited success because the ability of muscles to reinnervate decreases with time. • To circumvent this issue, Terzis describes a ‘mini hypoglossal’ nerve transfer as a ‘babysitter’ of the facial muscles. ∘ XII rapidly reinnervates the facial muscles while waiting for CFNG axons to grow across the face. The Head and Neck 253 Other donor nerves • Glossopharyngeal • Trigeminal • Accessory • Ipsilateral C7 • Phrenic. • None is popular due to increased donor morbidity and greater surgical access required compared to the XII–VII transfer. Local muscle transposition • Local and regional muscles can be transferred to produce facial movement. • Most options are motored by V, which will not produce true mimetic function. Temporalis muscle • A strip can be raised and folded over the zygomatic arch to reach the eye or oral commissure. • Labbé uses a different technique by detaching its coronoid insertion: ∘ The tendon is rerouted to the corner of the mouth through a cheek pocket. ∘ Additional length is achieved by repositioning the muscle’s origin on the skull. Masseter muscle • It is released from the mandible and transposed to the orbicularis oris. • Results in a lateral vector of pull. Digastric muscle • Used for isolated mandibular branch palsy to restore lower lip depressor function. • Divided through its central tendon, which is flipped up to the inferior orbicularis oris. • Its native nerve supply can be preserved, or it can be motored by a CFNG. Free functioning muscle transfer • Brings functioning muscle from a distant site to the face. • Preferred by many surgeons because the precise origin, insertion, tension and location of the muscle can be controlled. • Procedure of choice for congenital palsy due to lack of native facial muscle and nerve. • Less likely to fully succeed in older patients due to decreased potential for nerve regeneration, but age is not an absolute contraindication. • Can be done in one or two stages, depending on whether CFNG is required. One stage procedure • Muscle is harvested with its neurovascular bundle, revascularised in the face and the motor nerve is sutured directly to a branch of the contralateral facial nerve. ∘ The ipsilateral VII can be used if available, but this is unusual. ∘ If neither facial nerve is available, nerve to masseter is commonly used. 254 Chapter 3 • Advantages of the one stage procedure: ∘ Functional improvement within a few months. ∘ Nerve graft not required therefore there is no donor defect. ∘ Axons only have to regenerate over a single suture line. ∘ A second operation is avoided. • Disadvantages of the one stage procedure: ∘ Relative lack of suitable muscles with a nerve of sufficient length. – Typically limited to gracilis, latissimus dorsi and serratus anterior. ∘ The length of nerve required to reach the contralateral VII precludes use of one stage gracilis in children and people of short stature. Two-stage procedure • The first stage involves placing a CFNG. • The second stage is done once the CFNG has matured (confirmed by Tinel’s sign). • A free muscle flap is inset into the face through a facelift incision. • Location of the inset depends on the smile vector of the normal side: ∘ Proximally, can attach to temporalis fascia, zygomatic arch or parotid fascia. ∘ Distally, can insert into upper and lower lip, modiolus, alar base. • The muscle is revascularised to the facial vessels. • The CFNG is sutured to the motor nerve of the muscle. • The following muscles may be used as free functioning transfers: ∘ Gracilis ∘ Pectoralis minor ∘ Latissimus dorsi ∘ Serratus anterior ∘ Rectus abdominis ∘ Rectus femoris ∘ Abductor hallucis. • Each has its advocates; none completely substitutes for the subtle movements of the face. Treatment of Möbius syndrome • The facial nerve cannot be used because both sides are abnormal. • There may also be abnormalities of the remaining motor donor nerves. • The most common nerve used in Möbius is the nerve to masseter. ∘ This is found deep to the zygomatic arch, where masseter takes origin. • Other nerves include the accessory and hypoglossal. Abnormalities of the ear Embryology • The external ear begins to form during the 5th week of gestation. ∘ The external ear is also called the auricle or pinna. • Ectoderm induces the underlying mesoderm to differentiate into cartilage. The Head and Neck 255 • By 6 weeks, it is comprised of: ∘ Three anterior hillocks, from the first branchial arch. ∘ Three posterior hillocks, from the second branchial arch. ∘ Between the two arches is the first branchial cleft, the future external auditory meatus. • The hillocks of His – named after Wilhelm His – were mistakenly assumed to be precursors of specific parts of the ear. • In reality, hillocks blend into a bland mass before a recognisable auricle is formed: ∘ The ventral part of the mass forms tragus, antitragus, lobule and helical root. ∘ The dorsal part forms concha, triangular fossa, inferior crus and body of the antihelix. ∘ Most of the helix, scaphoid fossa and superior crus of the antihelix derive from the free ear fold. – This is a separate area just posterior to the hillocks of the second arch. • A recognisable auricle is formed by the ninth week. • The middle ear cavity and Eustachian tube develop from the first pharyngeal pouch. • The inner ear forms by invagination of an otic placode in the ectoderm of the head. The surface anatomy of the ear Helical rim Superior crus Triangular fossa Inferior crus Scaphoid fossa Cymba concha Root of helix Antihelix External auditory meatus Conchal fossa Tragus Tail of the helix Cavum concha Intertragal notch Antitragus Lobule Blood supply • The ear is supplied by branches of the external carotid artery: 1 Posterior auricular artery 2 Superficial temporal artery 3 Occipital artery. 256 Chapter 3 • There is extensive communication between all three arterial systems. • Venous drainage is to external jugular, retromandibular and superficial temporal veins. Nerve supply 1 Great auricular nerve ∘ Supplies lateral and medial aspects of the inferior half of the ear. 2 Lesser occipital nerve ∘ Supplies medial aspect of the superior half of the ear. 3 Auriculotemporal nerve ∘ Supplies lateral aspect of the superior half of the ear. 4 Auricular branch of the vagus nerve ∘ Known eponymously as Alderman’s or Arnold’s nerve. ∘ Supplies conchal fossa and external auditory meatus. ∘ Stimulation can cause vagal-induced coughing or vomiting. Classification • Tanzer classified auricular deformities into groups: ∘ I: Anotia ∘ II: Complete hypoplasia (microtia) – A: with atresia of the external auditory canal – B: without atresia of the external auditory canal ∘ III: Hypoplasia of the middle third of the auricle ∘ IV: Hypoplasia of the superior third of the auricle – A: constricted (cup and lop) ear – B: cryptotia – C: hypoplasia of the entire superior third ∘ V: Prominent ears. • Congenital deformities can be malformations or deformations: ∘ Malformations generally require surgical correction. ∘ Deformations can also be treated by moulding in the first months of life. Microtia • A malformed remnant of cartilage attached to a variable amount of soft tissue. • The most severe form is anotia – complete absence of auricular tissues. • The incidence of microtia is: ∘ One in 6000 in the Western world ∘ One in 4000 in Japan ∘ One in 1000 in Navajo Indians. • Males affected 2.5 times more frequently than females. • Right:left:bilateral ratio is approximately 6:3:1. • Due to its different embryological origin, the inner ear is usually spared. • However, the middle ear is usually abnormal. ∘ Most cases therefore benefit from bone conduction hearing aids. • Bilateral cases are fitted with hearing aids early, to help speech acquisition. The Head and Neck 257 • Hearing aids can be held against the skull with an elasticated headband, or anchored to the skull. ∘ The bone-anchored hearing aid (BAHA) involves insertion of a titanium osseointegrating implant into the skull behind the ear, followed by a percutaneous abutment. ∘ A battery powered sound processor clips to the abutment and transmits sound vibrations directly to the bone. • Exploration of the middle ear is not universally supported. ∘ There is a risk of damaging the facial nerve and inner ear for modest gains. • Associated syndromes usually have other first and second branchial arch anomalies: ∘ Treacher Collins syndrome ∘ Hemifacial microsomia – 1∕3 – 1∕2 of microtia patients have features of hemifacial microsomia. Reconstruction • The main options are: 1 Bone-anchored prosthesis. 2 Autologous reconstruction. 3 Alloplastic reconstruction. • Each can provide excellent results in the appropriate situation. • Educating patient and parents to allow an informed choice to be made is paramount. • Techniques using implanted polymers fell out of favour due to high rates of extrusion. ∘ However, some continue to use these materials without high complication rates. • The following help guide positioning of the new ear: ∘ The earlobe lies at the level of the tip of the nose. ∘ The helix attaches to the head at the level of the lateral canthus. ∘ The distance between the point of attachment of the helix to the head and the lateral orbital margin is approximately the height of the ear, 65–70 mm. ∘ The highest point of the helix is level with the arch of the eyebrow. ∘ The external auditory meatus is level with the midpoint between eyebrow and tip of nose. • Reconstruction is more difficult in cases of bilateral microtia, low hairlines and when there are associated syndromic anomalies. Bone-anchored prosthesis • Bone anchoring is superior to securing a prosthesis with adhesive. • A prosthesis is attached to osseointegrated implants. • Osseointegration was discovered by Brånemark; many implant systems bear his name. ∘ Osseointegration is the formation of a direct interface between an implant and bone, without intervening soft tissue. ∘ Implants are coated with an osseoconductive porous layer containing titanium oxide or calcium hydroxyapatite to facilitate this process. • Placement of an implant broadly involves: 1 CT scans to plan precise placement of implants into good bone stock. 2 Remnants of the microtic ear are excised; overlying soft tissues are thinned. 258 Chapter 3 3 Implants are traditionally placed in two stages: – The first stage involves screwing the osseointegrating component into the mastoid. – At a second stage some months later, the implant is uncovered and a percutaneous abutment attached to it. • Two or three such implants are usually required. – This allows a prosthetic ear to be attached using magnets or ‘bar and clip’ method. – Implants have since been developed that can be placed in a single stage. • Disadvantages of prosthetic reconstruction include: ∘ Risk of implant infection. ∘ Need for lifelong maintenance. ∘ Continued patient perception of having an artificial body part. Autologous reconstruction • Timing of surgery is governed by physical and psychological factors: ∘ The ear has attained 85% of its adult size by age 4 years. ∘ Availability of rib cartilage is usually sufficient for the Brent technique by age 6 years. – Patients need to be older for the Nagata technique. ∘ Teasing at school is not usually a problem until 7–10 years. • Reconstruction should be done through virgin, unscarred skin. ∘ This is taken into account when middle ear or craniofacial surgery is also required. • Ear reconstruction by the Brent method is performed in the following way. ∘ He waits at least 3 months between stages. Stage I Planning • Contours of the normal ear are traced onto a sheet of film. • The tracing is reversed and placed in a similar position to the contralateral ear. Harvesting cartilage • The film tracing is used to help choose which cartilages will work best. ∘ Brent prefers the configuration of cartilage in the contralateral chest. • A wood-carving chisel is used to sculpt the cartilage. • The helical rim is secured to the main construct using clear nylon sutures. Creation of a subcutaneous pocket • This is dissected through an incision anterior to the auricular vestige. ∘ Any residual cartilage is removed. • The cartilaginous construct is inserted into the pocket. • Suction drains prevent fluid accumulation and coapt the pocket to the cartilage. Stage II • The lobule is rotated to the correct anatomical site. The Head and Neck 259 Stage III • The construct is elevated to create the postauricular sulcus: ∘ An incision is made just outside the helical rim. ∘ Postauricular scalp is advanced into the sulcus. ∘ The posterior ear is resurfaced with split-thickness skin graft. Stage IV • Conchal cartilage from the normal side is used to reconstruct the tragus. • The Nagata method differs in the following ways: ∘ The cartilage framework consists of a baseplate, onto which separate helix, antihelix and tragus components are mounted using stainless steel sutures. ∘ The lobule is transposed through an anterior incision at the same time as the cartilage construct is inserted into a pocket through a posterior incision. ∘ The second stage involves elevation of the new ear, placement of a wedge of cartilage in the postauricular sulcus to maintain projection and coverage of the whole area with a temporoparietal fascial flap and split skin graft. Alloplastic reconstruction • Involves placing an ear-shaped implant into a subcutaneous pocket. • Ready-made ‘off-the-shelf’ generic ear-shaped implants are available. • Alternatively, a custom-made ear can be carved from a block of Medpor. • Alloplastic implantation is associated with high rates of extrusion. • Covering the implant with a temporoparietal fascial flap decreases the complication rate. Prominent ears • A common aesthetic problem affecting 1–2% of individuals. • The definition of prominent ears is largely subjective. ∘ Objective helix to mastoid prominence of more than 2 cm, and a pinna to mastoid angle of more than 25∘ , usually gives the appearance of a prominent ear. • Classified according to the underlying structural abnormality: 1 Excessive height of the conchal wall. 2 Absence of the antihelical fold (conchoscaphal angle >90∘ ). 3 A combination of both. Otoplasty • Otoplasty refers to correction of any deformity or defect of the external ear. ∘ However, it is most commonly used to describe correction of prominent ears. • Prominent ears can be corrected by: ∘ Suture techniques. ∘ Excisional techniques. ∘ Operative or nonoperative cartilage moulding techniques. ∘ Combinations of techniques. 260 Chapter 3 • Operating is avoided before the age of 4 due to risk of growth disturbance. • Surgery should not be undertaken solely due to parental wishes. ∘ If the child resists the idea of surgery, treatment should be deferred. • Surgery is usually done under general anaesthesia. ∘ It can be done under local anaesthetic, but not usually until adolescence. Suture techniques • Rely on strength of sutures to hold cartilage in the desired position. • For this reason, permanent sutures armed with round-bodied needles are used. Concha-mastoid sutures • Known as Furnas sutures. • Pass between cartilage of posterior concha and fascia overlying the mastoid. • They pull the concha towards the head, reducing ear prominence. Mustardé sutures • Mattress sutures between cartilage of the scaphoid and conchal fossae. • They increase the degree of antihelical folding. Fossa-fascia sutures • Mattress sutures between scaphoid fossa and temporal fascia. • Used to correct persistent prominence of the upper third. Excisional techniques Skin excision alone • Excision of posterior skin without correcting cartilage results in recurrence. • However, skin excision can correct a prominent lobule. Conchal excision • Reduces the height of the conchal wall. • A crescent of cartilage is excised from the posterior conchal wall. • Performed through an anterior or posterior approach. Cartilage moulding techniques Nonoperative • Involves placing a soft tube in the presumptive scaphoid fossa and securing it with tape. • The time required to achieve permanent improvement varies from a couple of weeks at birth to a few months at 6 months of age. • Auricular cartilage is malleable during the first 3 months of life due to maternal oestrogens. ∘ Good results are obtainable after 3 months but the success rate wanes. Operative • Operative techniques rely on Gibson’s principle. ∘ This states that cartilage bends away from its scored surface. The Head and Neck 261 • Anterior scoring of cartilage through an open posterior approach was described by Chongchet. • Closed techniques, where cartilage is scored through small anterior or posterior skin incisions, have also been described – notably by Stenström. Other auricular abnormalities The constricted ear • Characterised by deficiency in the circumference of the helix: ∘ Lop ear is downward folding of the superior helix. ∘ Cup ear combines features of lop ear with a prominent ear. • Difficult to correct once the window for nonoperative moulding has passed. • Usually managed with a combination of otoplasty techniques. Stahl ear • Also known as Spock ear, after the Star Trek character. • An abnormal third crus traverses the superior third of the ear, thus flattening the helix. • Amenable to nonoperative moulding; surgical correction is difficult. Cryptotia • The upper pole of the helix is buried beneath the temporal skin. • Rare in Caucasians but affects one in 400 Japanese. • Surgery involves elevating the ear and creating a posterior sulcus with skin grafts or flaps. Telephone deformity • An acquired deformity, usually following prominent ear correction, where there is relative prominence of the upper and lower thirds. • This gives a C-shaped helical rim when viewed from behind. • A reverse telephone deformity is due to excessive prominence of the concha relative to the upper and lower poles. Further reading Craniofacial surgery Baser ME, Friedman JM, Joe H et al. Empirical development of improved diagnostic criteria for neurofibromatosis 2. Genet Med 2011;13(6):576–81. Ferner RE, Huson SM, Thomas N et al. Guidelines for the diagnosis and management of individuals with neurofibromatosis 1. J Med Genet 2007;44(2):81–8. Tessier P. Anatomical classification facial, cranio-facial and latero-facial clefts. J Maxillofac Surg 1976;4(2): 69–92. Tessier P, Guiot G, Derome P. Orbital hypertelorism. II. Definite treatment of orbital hypertelorism (OR.H.) by craniofacial or by extracranial osteotomies. Scand J Plast Reconstr Surg 1973;7(1):39–58. Wagener S, Rayatt SS, Tatman AJ et al. Management of infants with Pierre Robin sequence. Cleft Palate Craniofac J 2003;40(2):180–5. 262 Chapter 3 Whitaker LA, Pashayan H, Reichman J. A proposed new classification of craniofacial anomalies. Cleft Palate J 1981;18(3):161–76. Cleft lip and palate Markus AF, Delaire J. Functional primary closure of cleft lip. Br J Oral Maxillofac Surg 1993;31(5):281–91. Mulliken JB, Schmidt AG. Gustav Simon’s band and the evolution of labial adhesion. J Craniofac Surg 2013;24(1):108–14. Sandy J, Williams A, Mildinhall S et al. The Clinical Standards Advisory Group (CSAG) Cleft Lip and Palate Study. Br J Orthod 1998;25(1):21–30. Schweckendiek W, Doz P. Primary veloplasty: long-term results without maxillary deformity. a twenty-five year report. Cleft Palate J 1978;15(3):268–74. Stanier P, Moore GE. Genetics of cleft lip and palate: syndromic genes contribute to the incidence of non-syndromic clefts. Hum Mol Genet 2004;13 Spec No 1:R73–81. Head and neck cancer Brown JS, Shaw RJ. Reconstruction of the maxilla and midface: introducing a new classification. Lancet Oncol 2010;11(10):1001–8. Chim H, Salgado CJ, Seselgyte R et al. Principles of head and neck reconstruction: an algorithm to guide flap selection. Semin Plast Surg 2010;24(2):148–54. Ferlito A, Robbins KT, Shah JP et al. Proposal for a rational classification of neck dissections. Head Neck 2011;33(3):445–50. Jewer DD, Boyd JB, Manktelow RT et al. Orofacial and mandibular reconstruction with the iliac crest free flap: a review of 60 cases and a new method of classification. Plast Reconstr Surg 1989;84(3):391–403. Menick FJ. Practical details of nasal reconstruction. Plast Reconstr Surg 2013;131(4):613e–30e. Robbins KT, Shaha AR, Medina JE et al.; Committee for Neck Dissection Classification, American Head and Neck Society. Consensus statement on the classification and terminology of neck dissection. Arch Otolaryngol Head Neck Surg 2008;134(5):536–8. Roland NJ, Paleri V (eds). Head and Neck Cancer: Multidisciplinary Management Guidelines, 4th edition. London: ENT UK, 2011. Wallace CG, Chang YM, Tsai CY et al. Harnessing the potential of the free fibula osteoseptocutaneous flap in mandible reconstruction. Plast Reconstr Surg 2010;125(1):305–14. Maxillofacial trauma Ehrenfeld M, Manson P, Prein J. Principles of Internal Fixation of the Craniomaxillofacial Skeleton. New York: Thieme, 2012. Oculoplastic surgery http://www.oculoplastics.info Tyers AG, Collin JRO. Colour Atlas of Ophthalmic Plastic Surgery, 3rd edition. Oxford: Butterworth Heinemann, 2008. Zide BM, Jelks GW. Surgical Anatomy of the Orbit. New York: Raven, 1985. The Head and Neck 263 Facial palsy Chuang DC. Free tissue transfer for the treatment of facial paralysis. Facial Plast Surg 2008;24(2):194–203. Fattah A, Borschel GH, Manktelow RT et al. Facial palsy and reconstruction. Plast Reconstr Surg 2012; 129(2):340e–52e. House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985;93(2):146–7. Kanerva M, Poussa T, Pitkäranta A. Sunnybrook and House–Brackmann Facial Grading Systems: intrarater repeatability and interrater agreement. Otolaryngol Head Neck Surg 2006;135(6):865–71. Labbé D, Huault M. Lengthening temporalis myoplasty and lip reanimation. Plast Reconstr Surg 2000; 105(4):1289–97. Terzis JK, Tzafetta K. The “babysitter” procedure: minihypoglossal to facial nerve transfer and cross-facial nerve grafting. Plast Reconstr Surg 2009;123(3):865–76. Tzafetta K, Terzis JK. Essays on the facial nerve: Part I. Microanatomy. Plast Reconstr Surg 2010;125(3):879–89. Abnormalities of the ear Brent B. Technical advances in ear reconstruction with autogenous rib cartilage grafts: personal experience with 1200 cases. Plast Reconstr Surg 1999;104(2):319–34. Gosain AK, Recinos RF. A novel approach to correction of the prominent lobule during otoplasty. Plast Reconstr Surg 2003;112(2):575–83. Reinisch JF, Lewin S. Ear reconstruction using a porous polyethylene framework and temporoparietal fascia flap. Facial Plast Surg 2009;25(3):181–9. CHAPTER 4 The Breast and Chest Wall CHAPTER CONTENTS Breast anatomy, 264 Breast reduction, 265 Mastopexy, 267 Breast augmentation, 269 The tuberous breast, 277 Gynaecomastia, 278 Breast cancer, 280 Breast reconstruction, 290 Chest wall reconstruction, 298 Posterior trunk reconstruction, 305 Further reading, 306 Breast anatomy • The breast base extends vertically from 2nd–6th rib. ∘ Horizontally, it extends from the lateral margin of sternum to anterior axillary fold. ∘ The axillary tail of Spence extends superolaterally towards the axilla. • Each breast contains 15–20 lobes, which radiate outward from the nipple. ∘ A lobe contains a variable number of lobules; each contains 10–100 alveoli. ∘ Each alveolus has a small duct that joins with others to form a single duct for each lobule. ∘ This duct system opens onto the nipple as lactiferous ducts. ∘ Most breast cancers originate from this ductal system. • Adjacent lobes are separated by fibrous septa from skin to pectoral fascia. ∘ Septa in the upper breast are well developed, known as suspensory ligaments of Astley Cooper. • The thin horizontal fibrous septum of Würinger originates from pectoral fascia along the fifth rib and curves upwards into vertically oriented medial and lateral ligaments. ∘ This septum attaches the breast to the sternum and lateral edge of pectoralis minor. ∘ Carries the main nerve supply to the nipple together with intercostal perforators. Arterial supply • Internal mammary artery perforators • Pectoral branches of the thoracoacromial axis Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 264 The Breast and Chest Wall 265 • Lateral thoracic artery • Lateral branches of 3rd–5th intercostal arteries. Nerve supply • • • • Anterior cutaneous branches of 2nd–6th intercostal nerves. Anterior cutaneous branches of 3rd–6th lateral cutaneous nerves. Supraclavicular branches of cervical plexus. Main supply to the nipple is from branches of the 4th lateral cutaneous nerve. Surface anatomy • Penn described ‘ideal’ breast measurements: ∘ Sternal notch to nipple distance is roughly equivalent to the distance between the nipples. – This is 21 cm on average. ∘ Nipple to inframammary crease is approximately 6.8 cm. ∘ Areolar diameter varies from 3.8 to 4.5 cm. Brassiere size • Estimating bra size is difficult: sizes vary between countries and manufacturers. • This mathematical method of bra sizing is a guide at best. Band size • In the United Kingdom, this is based on chest circumference: ∘ Measured in inches at the inframammary fold (IMF). ∘ Either 4 or 5 inches are added to make an even number. ∘ Band sizes typically range from 28 to 46 inches. Cup size • Based on the difference between band size and chest circumference around the most prominent part of the breasts: ∘ <1 inch difference – AA cup ∘ 1 inch difference – A cup ∘ 2 inch difference – B cup ∘ 3 inch difference – C cup ∘ 4 inch difference – D cup ∘ 5 inch difference – DD cup. Breast reduction History • • • • Thorek (1920s): free nipple graft technique. Wise (1950s): keyhole pattern of skin incision. Strombeck (1960): horizontal bipedicle technique. Skoog (1963): modified Strombeck; superomedial pedicle technique. 266 • • • • • • • • Chapter 4 McKissock (1972): vertical bipedicle technique. Weiner (1973): superior pedicle technique. Ribeiro (1975): inferior pedicle technique. Lejour popularised the vertical scar technique originally described by Lassus. Benelli (1990): round-block technique. Hall-Findlay (1999): modified the vertical scar technique with a medial pedicle. Hammond (1999): short scar periareolar inferior pedicle reduction (SPAIR) technique. Hamdi (2005): uses the septum of Würinger to maintain vascularity and sensation to the nipple–areola complex (NAC). Techniques • Classified by: ∘ Pattern of skin excision ∘ Design of NAC pedicle. Patterns of skin excision • Wise pattern, also known as a ‘keyhole’ due to its shape. ∘ Alternatively known as an ‘inverted T’ due to the resultant scars. • Regnault described a ‘B’-shaped skin excision. • Lejour popularised vertical skin excision. • Marchac described vertical excision with short lateral extensions. • Benelli popularised the periareolar technique. Design of the pedicle • Blood reaches the NAC via a pedicle from the chest wall, composed of: ∘ Glandular tissue, or ∘ Glandular tissue and de-epithelialised dermis, or ∘ Horizontal septum of Würinger. Free nipple graft technique • The NAC is removed and replaced as a graft. • Advantages: ∘ Avoids morbidity associated with a long pedicle. ∘ Relatively quick and easy to perform. • Disadvantages: ∘ Poor ‘take’ of the NAC. ∘ Loss of nipple sensation. • For these reasons, the technique is generally reserved for older patients requiring large reductions. Inferior pedicle technique • Popular technique of breast reduction. The Breast and Chest Wall 267 • Advantages: ∘ Relatively simple to learn. ∘ May preserve nipple sensation via the 4th lateral cutaneous nerve. • Key points of the inferior pedicle technique: 1 The pedicle must remain attached to the chest wall. – Avoid undermining the pedicle. 2 The base of the pedicle can be inclined laterally. – Increases the chance of including a sensory branch in the pedicle. 3 In firm breasts, the width of the keyhole pattern should be narrowed. – Otherwise undue tension may be placed on the skin flaps. 4 The NAC should never be sited too high. – A high nipple is difficult to correct. – At the end of the procedure, the nipples should lie just below the most prominent part of the breast. Medial pedicle technique • Also a popular technique of breast reduction. • With the patient upright it looks like more of a superomedial pedicle. • The Hall-Findlay technique combines it with vertical skin excision. • Key technical points: 1 Create a full thickness dermoglandular pedicle down to chest wall, without exposing pectoralis fascia. 2 Parenchymal resection predominantly inferiorly and laterally. 3 The inferior border of the pedicle becomes the medial breast pillar after the nipple is rotated into position. 4 Pillars are sutured together to cone the breast; skin redrapes over the parenchyma. Mastopexy • Corrects ptosis by elevating breast tissue and NAC. ∘ Ptosis is derived from the Greek, meaning ‘to fall’. • Involves excision of breast skin without parenchymal resection. Classification • Regnault classified breast ptosis: First degree ptosis • Nipple lies at the level of the IMF, above the lower contour of the gland and skin brassiere. Second degree ptosis • Nipple lies below the IMF but above the lower contour of the breast and skin brassiere. 268 Chapter 4 Third degree ptosis • Nipple lies below the IMF and at the lower contour of the breast and skin brassiere. Pseudoptosis • The major portion of the breast mound lies below the IMF while the NAC remains at the level of the IMF. • This appearance can occur after breast reduction. Surgical correction of ptosis Augmentation only • An implant can increase breast volume and improve contour. • Can treat minor degrees of ptosis. • Not suitable for more severe ptosis because: 1 An excessively large implant would be required to tighten the slack skin. 2 Ptotic skin may hang over the implant creating a ‘double-bubble’ or ‘Snoopy-nose’ appearance. Skin excision and glandular remodelling • Four main scar patterns: Periareolar technique • Involves de-epithelialising a concentric ring of tissue around the NAC. • Breast skin is tightened by suturing the outer ring to the NAC. • Benelli described a ‘round-block’ technique of securing the NAC after circumareolar mastopexy: 1 A purse-string (the ‘round-block’) reduction of the outer dermal circumference with a permanent suture. 2 A ‘skin compensation suture’: horizontal bites of the outer dermal circumference, but vertical bites of the NAC. • Advantages: ∘ Reduces the tendency of the NAC to stretch. ∘ Reduces the tendency of nipple herniation through the ‘round-block’. ∘ Minimises puckering as a larger circle is closed to a smaller diameter NAC. Vertical scar technique • Adds a vertical or oblique limb to the periareolar skin excision: ∘ Allows more skin to be excised. ∘ Helps elevate the NAC. Inverted T scar technique • The full Wise ‘keyhole’ pattern is used for severe ptosis: ∘ Removes large amounts of excess skin. ∘ Transposes the NAC into its correct position. The Breast and Chest Wall 269 L-shaped scar technique • Reduces the length of the horizontal component of the inverted T technique by eliminating the medial component and shortening the lateral component. • Best suited to correcting first or second degree ptosis. Complications of mastopexy and breast reduction General • Risks of general anaesthesia • Chest infection and atelectasis • Deep vein thrombosis or pulmonary embolism Specific Early • Altered nipple sensation (20%) • Haematoma (1%) • NAC necrosis (<0.5%) • Infection. Intermediate • Wound healing problems (5%) • Seroma • Fat necrosis. Late • Inability to breastfeed (up to 50%) • Hypertrophic or keloid scarring • Lumpiness • Under- or over-resection • Asymmetry • Dog ears. Breast augmentation History 1890: breasts augmented with paraffin wax injections. 1950: polyvinyl sponge implants available. 1960s: silicone gel prosthetic augmentation first performed by Cronin and Gerow. Estimated that 3% of women in the United States have undergone breast augmentation. • In the United Kingdom, >10,000 women had breast implants for cosmetic purposes in 2011. • • • • 270 Chapter 4 Classification • Implant-based breast augmentation can be classified by: ∘ Composition and surface of the implant shell ∘ Contents of the implant ∘ Implant shape ∘ Incision through which the implant is inserted ∘ Site of implant placement. Implant shell Texture of the shell • Smooth • Textured ∘ Believed to induce less capsular contracture. Composition of the shell • Most breast implant shells are silicone. • Polyurethane foam coated implants are increasing in popularity. ∘ Reported to have lower rates of capsular contracture. ∘ Concerns over formation of toluene by-products (carcinogenic in animals) resulted in their temporary withdrawal from the market. ∘ This is discussed further in Chapter 1, ‘Alloplastic implantation’. Implant content • Liquid silicone gel • Cohesive silicone gel • Saline • Hydrogel • Triglyceride • Hyaluronic acid • Only implants filled with silicone (semi-liquid or cohesive) or saline are available in the United Kingdom. Shape • Round • Anatomically shaped ∘ Designed to resemble the natural breast contour. ∘ Less upper pole projection; more lower pole projection. ∘ Anatomical implants have various projections, heights and widths. – This allows selection of an implant for a specific breast shape. ∘ Particularly suitable for thin patients at risk of excessive upper pole fullness. • There is controversy about whether shaped or round implants produce a better result: ∘ Proponents of anatomical implants claim they produce better breast shape. ∘ Proponents of round implants argue that: – Round implants become anatomically shaped when held upright. – Anatomical implants may rotate within their pocket. The Breast and Chest Wall 271 Incisions for insertion Inframammary incision • Most common method of inserting breast implants. • Advantages: good exposure; ease of pocket dissection. • Disadvantage: visible scar. Axillary incision • Relatively inconspicuous scar. • Pocket dissection, particularly medially and inferiorly, can be difficult. ∘ If this is not done adequately, implants tend to displace superiorly. Periareolar incision • Concealed scar. • Nipple paraesthesia and scar tenderness may occur. Umbilical incision • Expansion devices are inserted via the umbilicus to create a cavity under the breast. • Collapsible saline implants are then inserted through the umbilical incision. • Despite numerous proponents, this approach is not widely practised. Endoscopic insertion • The pocket can be dissected endoscopically. • Reduces the length of the incision. • Useful for inflatable implants inserted via an umbilical or axillary approach. Site of implant placement Subglandular pocket • Deep to breast tissue but superficial to pectoralis fascia. Subfascial pocket • Described by Graf (1998). • Pocket is between pectoralis fascia above and pectoralis major below. • May decrease visibility of implants and reduce risk of capsular contracture compared to subglandular placement. Subpectoral pocket • Deep to pectoralis major but superficial to pectoralis minor. • The lower pole of the implant may lie inferior to the edge of the muscle. Dual plane • Described by Tebbetts; a variation of subpectoral plane augmentation. • In addition to a subpectoral pocket, subglandular dissection extends above the inferior border of pectoralis major for a variable distance towards the superior border of the NAC. • Allows both implant placement and soft tissue redraping, which can avoid a double-bubble deformity in certain patients with ptosis. 272 Chapter 4 Submuscular pocket • Most of the pocket lies under pectoralis major. • Laterally it lies under serratus anterior. • Inferiorly it lies under the fascia of rectus abdominis. • This technique was initially advocated by Scott Spear. • He has since changed his practice with the advent of acellular dermal matrix (ADM), which is used to ensure total implant coverage. Pocket fashioned with acellular dermal matrix • ADM is becoming popular in breast surgery. • It is used in a variety of ways in both primary and secondary augmentation: ∘ Within the pocket to bolster areas of thin tissue. ∘ To minimise visible rippling. ∘ To support the lower pole of the implant and maintain IMF position. • ADM is said to reduce incidence of capsular contracture. • It is discussed further in ‘Breast reconstruction’ and ‘Chest wall reconstruction’ The silicone controversy • In the early 1980s, concerns arose over whether silicone implants were responsible for: ∘ Some types of autoimmune disease ∘ Increased risk of breast cancer ∘ Difficulties in screening for cancer. • In 1992, the US Food and Drug Administration (FDA) removed all silicone gel-filled breast implants from the market. • Following years of investigation, the FDA approved specific types of Allergan and Mentor® silicone gel-filled breast implants in 2006. • A condition of approval is that each manufacturer conducts six studies to assess the long-term performance and safety of their devices. • The ‘Core’ study was one such study, designed to follow women for 10 years and assess effectiveness of magnetic resonance imaging (MRI) in detecting implant rupture. • Allergan’s Core study enrolled 715 women; Mentor’s Core study enrolled 1008. Findings of the IRG in the United Kingdom • An Independent Review Group (IRG) was set up in the United Kingdom to examine evidence for claims that silicone had adverse health effects. • In 1998, the report concluded silicone breast implants are not associated with greater health risk compared to other surgical implants. • There was no evidence of: ∘ Association with abnormal immune response. ∘ Association with typical or atypical connective tissue diseases or syndromes. ∘ Increased risk of connective tissue disease in children of implanted women. The Breast and Chest Wall 273 • Silicone implants are associated with a number of local complications: ∘ Implant rupture ∘ Capsule formation. • The report recommended a national implant registry to record details of all women undergoing breast augmentation. Findings of IMNAS in the United States • In the United States, the Institute of Medicine of the National Academy of Science (IMNAS) released its final report in June 1999, concluding: ∘ No evidence that silicone implants are responsible for any major diseases. ∘ Women are exposed to silicone constantly in their daily lives. ∘ No evidence that recurrent breast cancer is more prevalent in women with implants. ∘ Silicone breast augmentation is not a contraindication to breastfeeding. – Cows’ milk and infant formulas contain higher levels of silicone than breast milk from women with silicone implants. Lymphoma • In 2008, Dutch researchers studied a group of women with a rare lymphoma. • A case–control study found women with breast implants had a higher association with a rare anaplastic large T-cell lymphoma (ALCL) subtype than those without implants. ∘ The odds ratio for ALCL associated with breast prostheses was 18.2. • Nevertheless, only 34 cases of ALCL have been reported in women with breast implants throughout the world. • This is a fraction of the estimated 10 million women who have received breast implants worldwide, making the absolute risk of ALCL very low. Capsule formation • Capsules form around all implants. • In some cases, capsules contract, causing discomfort and distortion. • Calcification of the capsule may occur. ∘ Rare within 10 years of implantation, but ubiquitous after 23 years. Aetiology • Cause of capsular contracture is unknown; suggested factors: ∘ Biofilm on the implant shell. – Biofilm: ‘a complex aggregation of microorganisms growing on a solid substrate’. – S. epidermidis was found in 90% of capsules removed for contracture, compared to 12% of capsules removed for other reasons. • Implants may be washed in antibiotics or povidone–iodine for this reason. ∘ Implant location. – Submuscular placement is said to be associated with less contracture. ∘ Implant size. – Implants >350 cc have greater incidence of contracture. ∘ Surface covering of the implant. – Polyurethane foam covered implants have less reported contracture. 274 ∘ ∘ ∘ ∘ Chapter 4 – The Allergan Core study showed textured and smooth silicone implants have similar contracture rates. • However, most textured implants were used in reconstruction patients, who were expected to have a higher capsular contracture rate than observed. Haematoma. Silicone gel bleed, causing local tissue irritation. Foreign body reaction. Genetic predisposition. Classification of capsular contracture • Baker classified capsular contracture: ∘ Grade I: the augmented breast feels as soft as an unoperated one. ∘ Grade II: minimal – implant palpable, but not visible. ∘ Grade III: moderate – implant easily palpable, and it (or distortion from it) is visible. ∘ Grade IV: severe – the breast is hard, tender, painful and cold. Distortion is often marked. Incidence • Data from the Core studies show Baker III/IV contracture rates of: ∘ Allergan Natrelle® implants (10 years): 18.9% for primary surgery; 28.7% for revision surgery. ∘ Mentor MemoryGel® (8 years): 10.9% for primary surgery; 24.1% for revision surgery. Treatment • Patients with Baker grade III or IV contracture often seek revision surgery. • Options include: 1 Closed capsulotomy – Squeezing the augmented breast until it ‘pops’, indicating capsule rupture. – Not recommended due to high recurrence rate, displacement or haematoma. 2 Open capsulotomy or capsulectomy – Capsulectomy associated with lower risk of recurrence, but more complications. – Capsulectomy decreases breast volume, which may not be desirable. • Capsulectomy may be preferred over capsulotomy in these circumstances: ∘ If the capsule is very thickened or calcified, causing contour irregularity. ∘ If the implant has ruptured, particularly if it is a Poly Implant Prothèse (PIP) implant. • Scott Spear advocates capsulectomy, either partial or total, with replacement of the implant in a dual plane. Poly Implant Prothèse (PIP) silicone implants • Manufactured by a French company of the same name. • Widely marketed in Europe, South America and Australia. • In 2009, French authorities found silicone gel used in the implants was industrial grade, intended for mattresses and cushions. ∘ This had been the case since 2001. The Breast and Chest Wall 275 • Case reports also indicated the 5-year risk of implant rupture was 2–6 times higher than expected. • Based on relatively poor data, 10-year PIP rupture rates are reportedly 15–30%. ∘ This is broadly comparable to Allergan (13% at 10 years) and Mentor (14% at 8 years). • Patients with PIP ruptures are more likely to have a local tissue reaction and lymphadenopathy. • Official tests carried out in 2010 by the UK Medicines and Healthcare products Regulatory Agency (MHRA) and its French and Australian counterparts revealed no evidence of genotoxicity or cytotoxicity associated with the industrial silicone used. Recommendations of the UK Department of Health Expert Group • Providers of PIP implants should offer consultation and investigation to determine whether implants are intact. • Patients whose providers are unwilling to do this should be referred to a specialist via their general practitioner (GP). • If there is any sign of rupture, explantation should be offered. • If the implants are intact, discussion with the patient should include: ∘ Risks of surgery for revision augmentation – greater than for primary augmentation. ∘ If the implants are not removed, there is ongoing risk of rupture. • If the patient decides against early explantation, annual review is offered. Joint surgical guidelines for PIP implants • Authored by five UK surgical organisations, including the British Association of Plastic Reconstructive and Aesthetic Surgeons (BAPRAS) and British Association of Aesthetic Plastic Surgeons (BAAPS). • Surgeons should remove or exchange implants using conventional techniques, through the original incision where possible. • Biopsy and capsulectomy is recommended for extensive capsular thickening, inflammation or contracture. • Biopsy or capsulectomy is not required for uncomplicated, soft capsules without evidence of silicone impregnation or local inflammation. • When there is extreme silicone contamination, consider deferring implant replacement. • Patients with extensive lymphadenopathy or parenchymal lumpiness should be investigated and discussed by a breast multi-disciplinary team (MDT). ∘ Patients should be informed of the additional risks of any planned axillary surgery. Consequences and complications of breast augmentation surgery • Normal post-operative sequelae of surgery: ∘ Swelling, hardness, discomfort, bruising, pain, altered sensation. ∘ Usually takes months until the final result is achieved. ∘ Most take a few weeks off work to recover. ∘ Risk of not being able to breastfeed after periareolar approach. • Implants have a finite lifespan; almost all require replacement at some point. 276 Chapter 4 • Implants can present difficulties during routine mammography. ∘ Specialised ‘Eklund push-back views’ improve visualisation of breast tissue during mammography. ∘ Implants do not adversely affect breast cancer detection, stage at diagnosis or survival. • Patients should be told about these specific complications: Early • Infection, bleeding, seroma (1–3%) ∘ Deep infection often requires explantation. • Decreased nipple sensation (15%) ∘ Nipples can also become hypersensitive and painful – may take months to improve. Late • Problematic capsular contracture • Rupture rate ∘ The Allergan Core study showed a rupture rate of 13% for subjects and 7.7% for implants at 10 years (primary augmentation, revision augmentation and reconstruction). – Up to 35% of ruptures are asymptomatic. ∘ The Mentor Core study showed a rupture rate of 13.6% at 8 years (primary augmentation). ∘ The Danish MRI study showed a 15% rupture rate at 10 years. • Problematic scarring (5%) • Visible creasing and folding of the implant. Other techniques of breast augmentation Lipofilling • Most suitable in these circumstances: ∘ For augmentation by one cup size. ∘ For increased upper pole fullness. ∘ Following ‘conservative’ breast cancer surgery. • Advantages: ∘ Relatively easy to learn. ∘ Less scarring than implant augmentation or flap reconstruction. • Disadvantages: ∘ Fat necrosis, oil cysts and microcalcification, which is visible on mammograms. – These changes can be differentiated from cancer by experienced radiologists. • Effects of stem cells on breast tissue are controversial. ∘ Long-term follow-up studies have not shown increased rates of local recurrence of cancer, but these case series are relatively small. • Recently, technical refinements have been described that achieve significantly larger breast augmentation, more fat graft placement and higher graft survival rates. • This involves using the Brava® device, a bra-like vacuum-based external tissue expander, that is said to enlarge the subcutaneous and periglandular tissue matrix. ∘ Brava may also increase the vascularity of the breast. • After 4 weeks of expansion, lipofilling is done into this expanded, vascular breast. • Disadvantages include wearing the Brava, which many cannot tolerate for prolonged periods of time. The Breast and Chest Wall 277 • Lipofilling in this procedure requires 10–14 needle puncture sites per breast, which carries a risk of hypertrophic or keloid scarring in certain patients. Hyaluronic acid • Non-animal stabilised hyaluronic acid (NASHA), also known as Macrolane™, was previously authorised for breast augmentation. • It is now known that Macrolane in the breast can make diagnosing breast cancer more difficult, particularly with mammography. • The manufacturer (Q-Med) has since discontinued this indication for its product. The tuberous breast • Also known as a constricted breast. • Characterised by: ∘ Deficient breast base dimension ∘ Tight, elevated IMF ∘ Elongated thin breast ∘ Herniation of the NAC ∘ Stretching of the areola ∘ Breast asymmetry is common. • The Northwood index was recently proposed as a more precise way to diagnose tuberous breasts. Classification of tuberous breast deformity • Von Heimburg classified tuberous breast deformity: ∘ Type I: Hypoplasia of the lower medial quadrant. ∘ Type II: Hypoplasia of the lower medial and lateral quadrants with sufficient skin in the subareolar region. ∘ Type III: Hypoplasia of the lower medial and lateral quadrants with deficient skin in the subareolar region. ∘ Type IV: Severe breast constriction, minimal breast base. Surgical correction • The tuberous breast is a difficult problem to correct. • Principles of correction: ∘ Reducing the size of the areola ∘ Correcting nipple herniation ∘ Dividing any constrictions within breast parenchyma ∘ Lowering and releasing the IMF ∘ Insertion of an implant or tissue expander. Minimal deformity • Usually correctable by insertion of an implant. • Lipofilling is also useful. 278 Chapter 4 More severe deformity • Usually treated with a combination of: ∘ Release of constrictions within breast parenchyma ∘ Insertion of a prosthesis or tissue expander ∘ Circumareolar mastopexy ∘ Round-block suture to limit NAC herniation. • Extreme cases may require importation of extra skin. ∘ Transposition of a medially based thoraco-epigastric flap from below the IMF has been described. Gynaecomastia • Enlargement of the male breast. • Incidence varies with age; trimodal distribution: ∘ Up to 90% of neonates have a degree of gynaecomastia. ∘ 75% of boys have evidence of gynaecomastia at puberty. – 75% of these have resolved within 2 years. – 7% of 17-year-old boys have significant gynaecomastia. ∘ 30% of middle aged men have significant gynaecomastia. Aetiology • Most cases are idiopathic. • Causes classified by three ‘P’s: Physiological • Neonatal • Puberty • Old age Pharmacological • Cimetidine • Digoxin • Diazepam • Spironolactone • Oestrogens • Cannabis • Alcohol • Anabolic steroids Pathological • Cirrhosis • Malnutrition • Hypogonadism • Thyroid disease • Testicular and pituitary tumours. The Breast and Chest Wall 279 Classification of gynaecomastia • Simon classified gynaecomastia: ∘ Grade 1: Small, visible breast enlargement, no skin redundancy. ∘ Grade 2A: Moderate breast enlargement without skin redundancy. ∘ Grade 2B: Moderate breast enlargement with skin redundancy. ∘ Grade 3: Marked breast enlargement with marked skin redundancy, i.e. pendulous female breasts. Pre-operative assessment History • • • • Duration of gynaecomastia Pain Drug use Symptoms suggestive of a pathological cause. Breast examination • Assess volume of gynaecomastia • Amount of excess skin • Palpation of a firm central core of breast tissue below the NAC • Abnormal breast masses. General examination • Genitalia • Liver palpation • Thyroid examination. Investigations • Further investigation indicated if abnormalities revealed on history and examination. ∘ The GP or endocrinologist may have already done this; results should be confirmed. • Common tests required are: ∘ Hormones: oestrogen, testosterone, prolactin, luteinising hormone, follicle stimulating hormone, thyroid function tests. ∘ Biochemistry: liver function, glucose. ∘ Karyotyping: may be required to confirm Klinefelter’s syndrome (47XXY). ∘ Imaging: ultrasound of the testes. Surgical correction • Techniques include liposuction, with or without excision. Liposuction • Liposuction is effective for mild deformities without a significant core of breast tissue. • Liposuction may also be used as an adjunct to excisional surgery. • Ultrasound-assisted liposuction (UAL) has emerged as an effective treatment. ∘ At higher energy settings, UAL is effective at removing dense, fibrous parenchymal tissue that conventional liposuction does not address. ∘ May obviate the need for open excision of the residual breast tissue. 280 Chapter 4 Excisional techniques • Can be performed through a semicircular incision made just within the margin of the areola. ∘ Now known as Webster’s operation. ∘ Access to the breast tissue is relatively poor. • Access can be improved by de-epithelialising a doughnut of skin around the NAC: ∘ Breast tissue is accessed through a transverse incision passing across the de-epithelialised area, then curving below the NAC. ∘ Skin is closed similar to a circumareolar mastopexy. • Endoscopic resection of tissue via a small axillary incision has been reported. • Extremely large breasts require radical excision and nipple transposition on a dermal or dermoglandular pedicle. ∘ Such pedicles can add bulk to the end result; many advocate mastectomy and free nipple grafting instead. Breast cancer • • • • • • Most common cancer in the United Kingdom, despite being rare in men. Second most common cause of cancer death in women (15%), after lung cancer. Third most common cause of cancer death in the United Kingdom (7%). Annual incidence 157 per 100,000 women; 1 per 100,000 men. Lifetime risk of developing breast cancer in the United Kingdom is 1 in 8 for women. UK breast cancer mortality is decreasing, probably due to earlier diagnosis, more effective treatment and declining use of hormone replacement therapy (HRT). Risk factors Reproductive factors • • • • • Early menarche; late menopause. Age >30 at first childbirth. Parity – childbearing reduces breast cancer risk. Breastfeeding reduces risk. Exogenous hormones. ∘ Increased risk with oral contraceptive pill and HRT. Breast factors • High breast density – more glandular tissue, less fatty tissue. • Previous breast cancer. • Atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH). ∘ These confer fivefold increased risk. • Lobular in situ neoplasia (LISN) ∘ Up to 11 times greater risk of developing cancer in either breast. • Previous breast irradiation early in life. Genetic factors Family history • A woman with one affected first degree relative (mother or sister) has double the risk. ∘ This risk increases when two or more relatives are affected. The Breast and Chest Wall 281 • Nevertheless, over 85% of women who have an affected close relative never develop breast cancer. • In addition, 85% of women with breast cancer have no family history. Gene mutations • Mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 account for the majority of families with four or more affected members. • 1 in 450 women in the general population carry a mutation in one of these genes. ∘ These mutations probably account for 2% of all breast cancers. ∘ Mutations show autosomal dominant inheritance. • Female carriers of BRCA1 gene mutations have: ∘ Up to 65% risk of breast cancer and 46% risk of ovarian cancer by age 70. • Female carriers of BRCA2 gene mutations have: ∘ Up to 57% risk of breast cancer and 23% risk of ovarian cancer by age 70. • Increased breast cancer risk is also seen with mutations in TP53 gene (Li–Fraumeni syndrome) and PTEN gene (Cowden’s syndrome). Other factors • Age – the older the woman, the higher the risk. ∘ 80% of new breast cancer cases occur in women >50 years. • Increased body weight. • Lack of physical activity. • Excess alcohol consumption. • Caucasian race. Classification • Breast cancer is a heterogeneous group of tumours; classified by: ∘ Distribution within the breast ∘ Histological type ∘ Tumour grade ∘ Tumour node metastasis (TNM) stage ∘ Receptor status. Distribution within the breast • A multifocal tumour has two or more foci within one breast quadrant. • A multicentric tumour has two or more foci within different breast quadrants. Histological type 1 Non-invasive tumours 2 Invasive tumours. Non-invasive tumours Ductal carcinoma in situ (DCIS) • Characterised by dysplasia confined to epithelial cells of mammary ducts. ∘ Bilateral in 10% of cases; multicentric in 20% of cases. • DCIS is harmless per se, but up to 60% develop invasive breast cancer. 282 Chapter 4 • Small lesions are usually treated by local excision. • Larger lesions or lesions within smaller breasts may require mastectomy. Lobular in situ neoplasia (LISN) • Formerly known as lobular carcinoma in situ. • Usually occult; detected as an incidental finding. • Considered a marker, rather than a precursor, of breast cancer. • Bilateral in 40% of cases; multifocal in 60% of cases. • Risk of breast cancer is approximately 1% per year. ∘ Some patients therefore opt for bilateral risk-reducing mastectomy. Invasive tumours • Ductal carcinoma represents 80% of invasive tumours. • Lobular carcinoma represents 10% of invasive tumours. ∘ Invasive lobular carcinoma is more likely to be bilateral. • Other invasive tumours: ∘ Medullary carcinoma ∘ Tubular carcinoma ∘ Papillary carcinoma ∘ Mucinous carcinoma ∘ Adenoid cystic carcinoma. Grade • Scored on tubule formation, nuclear pleomorphism and mitotic count: ∘ Grade 1 (well differentiated, low grade) ∘ Grade 2 (moderately differentiated, intermediate grade) ∘ Grade 3 (poorly differentiated, high grade). TNM stage Primary tumour (T) • Tis: in situ carcinoma • T1: tumour ≤20 mm ∘ T1mic: microinvasion <1 mm ∘ T1a: tumour >1 mm but ≤5 mm ∘ T1b: tumour >5 mm but ≤10 mm ∘ T1c: tumour >10 mm but ≤20 mm • T2: tumour >20 mm but ≤50 mm • T3: tumour >50 mm • T4: tumour of any size with direct extension to chest wall ± skin ∘ T4a: extension to chest wall, not including only pectoralis muscle adherence/invasion ∘ T4b: ulceration ± ipsilateral satellite nodules ± oedema (including peau d’orange) of skin ∘ T4c: both T4a and T4b ∘ T4d: inflammatory carcinoma. The Breast and Chest Wall 283 Regional lymph nodes (N) • N0: no regional lymph node metastases • N1: mobile ipsilateral level I, II axillary lymph node(s) • N2a: ipsilateral level I, II axillary lymph nodes fixed to one another or other structures • N2b: clinically detected (including on imaging) ipsilateral internal mammary nodes without level I, II axillary lymph node metastases • N3a: ipsilateral infraclavicular lymph node(s) • N3b: ipsilateral internal mammary lymph node(s) and axillary lymph node(s) • N3c: ipsilateral supraclavicular lymph node(s). Distant metastases (M) • M0: no distant metastases • cM0(i+): no clinical or radiographic evidence of distant metastases, but deposits of molecularly or microscopically detected tumour cells in circulating blood, bone marrow or other nonregional nodal tissue that are no larger than 0.2 mm in a patient without symptoms or signs of metastases. • M1: distant detectable metastases as determined by classic clinical and radiographic means ± histologically proven larger than 0.2 mm. Stage grouping Stage Stage 0 Stage IA Stage IB Stage IIA Stage IIB Stage IIIA Stage IIIB Stage IIIC Stage IV T N M Tis T1 T0 T1 T0 T1 T2 T2 T3 T0 T1 T2 T3 T3 T4 T4 T4 Any T Any T N0 N0 N1mi* N1mi* N1 N1 N0 N1 N0 N2 N2 N2 N1 N2 N0 N1 N2 N3 Any N M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M1 *Micrometastases (>0.2 mm ± more than 200 cells, but <2.0 mm). 284 Chapter 4 Predicted survival • The American Joint Committee on Cancer Staging (AJCCS) gives these 5-year survival rates: ∘ Stage I: 92% ∘ Stage II: 73% ∘ Stage III: 50% ∘ Stage IV: 13%. Prognostic tools • These help decision making in the management of breast cancer: ∘ Nottingham Prognostic Index (NPI) ∘ Adjuvant! online prognostication and treatment benefit tool ∘ PREDICT online breast cancer survival tool. Receptor status • Determined by immunohistochemistry (IHC) or fluorescence in situ hybridisation (FISH). • Knowledge of receptor status helps target treatment with specific adjuvant therapy. ∘ Also provides prognostic information. • Receptors routinely tested for: ∘ Oestrogen receptor (ER) ∘ Progesterone receptor (PR) ∘ Human epidermal growth factor receptor 2 (HER2/neu). Oestrogen receptor (ER) • 70% of invasive breast cancers are ER positive. • ER positive cancer cells depend on oestrogen for growth. ∘ Targeted by drugs that interfere with oestrogen activity. Progesterone receptors (PR) • PR status is less important than ER status in predicting response to hormone treatment. • PR status influences likelihood of recurrence. Human epidermal growth factor receptor 2 (HER2/neu) • One of the four known members of the HER family. • HER2 positivity (determined by protein overexpression or gene amplification) is found in 15% of early stage invasive breast cancers. ∘ Associated with poor prognosis. • Tumours with high levels of these receptors may respond to drugs such as trastuzumab (Herceptin®). Triple negative breast cancer • Tumours not expressing ER, PR or HER2/neu are known as triple negative tumours. • They have a relatively poor prognosis. The Breast and Chest Wall 285 Biological tools • Rather than assessing receptor status in isolation, newer biological tumour analysis techniques look at all these factors together. ∘ Commercially available gene profiling kits include MammaPrint® and Oncotype DX®. • These categorise breast cancer into a number of molecular subtypes, which have different prognoses and different responses to treatments. • Four distinct molecular subtypes have been described so far: ∘ Luminal A (42–59%) ∘ Luminal B (6–19%) ∘ Triple negative/basal-like (14–20%) ∘ HER2+ (7–12%). • This is a relatively new area of research. Triple assessment • Breast cancer diagnosis is normally made on triple assessment: 1 Clinical examination 2 Imaging – mammography and/or ultrasound with MRI as required 3 Biopsy – fine needle aspiration cytology (FNAC) or needle core biopsy. Imaging Mammography • The UK NHS breast screening programme offers 3-yearly mammographic screening to all women between age 47 and 73. ∘ Routine screening between age 40 and 50 is controversial. • Patients with a strong family history should have earlier mammography. • Suspicious signs on mammography: ∘ Microcalcification ∘ Density changes ∘ Asymmetry ∘ Architectural distortion. • Mammography is less useful for <35-year-olds as the increased fibrous nature of young breasts makes detection of abnormalities more difficult. Ultrasound • Useful, particularly in younger patients, to differentiate between solid and cystic lesions. • Allows assessment, measurement and aspiration/biopsy of lumps. MRI • Not routinely used for breast imaging; can be useful if: ∘ There is discrepancy between clinical and radiological estimated extent of disease. ∘ There is a dense breast pattern on mammography. ∘ Core biopsy suggests invasive lobular cancer. 286 Chapter 4 MARIA • Multistatic Array Processing for Radiowave Image Acquisition (MARIA) recently reported as a new imaging modality that is more comfortable than a mammogram and suitable for a range of breast densities. Management • Usually multi-modal, including: ∘ Surgery ∘ Radiotherapy ∘ Chemotherapy ∘ Hormonal therapy ∘ Biological therapy. Surgical treatment Primary tumours • Breast conserving surgery ∘ Wide local excision (WLE) ∘ Quadrantectomy • Mastectomy ∘ Radical ∘ Extended radical ∘ Modified radical ∘ Simple ∘ Skin sparing ∘ Nipple sparing. Wide local excision (WLE) • Primarily indicated for selected patients with stage 1 or stage 2 disease. • Randomised trials report similar long-term survival for women treated by either WLE or mastectomy. ∘ However, most of these trials exclude patients with tumours >2.5 cm. • Not suitable for: ∘ Widespread disease ∘ Patients with small breasts. • Determining the extent of disease may require MRI in some cases, particularly for invasive lobular cancer or in dense breasts. • For impalpable lesions, a radiologist can lodge a fine wire into the lesion to allow its guided excision. ∘ Tumour removal is confirmed by X-raying the specimen, which should show the tip of the guidewire in the tumour. Quadrantectomy • Removes an entire quadrant of the breast. • Primarily used for T2 tumours. • Significant deformity may result if the defect is not reconstructed. The Breast and Chest Wall 287 Radical mastectomy • Developed and performed by William Stewart Halsted (1882). • Removes the entire breast with pectoralis major and minor, and axillary lymph nodes. Extended radical mastectomy • Combines radical mastectomy with intrapleural en bloc resection of internal mammary lymph nodes, approached by splitting the sternum. Modified radical mastectomy • Removes the entire breast and axillary lymph nodes with preservation of pectoralis muscles. Simple (total) mastectomy • Removes the entire breast without axillary nodes. • Usually done for: ∘ T3 or T4 tumours ∘ T2 tumours in patients with small breasts ∘ Multicentric tumours ∘ Small invasive breast cancer but with widespread DCIS. Skin sparing (subcutaneous) mastectomy (SSM) • Removes 90–95% of breast tissue but preserves most of the skin to facilitate reconstruction. • Breast tissue is excised through a periareolar incision. • Cancers involving skin are not suitable for SSM. • In large breasts, a Wise pattern can help reduce the skin envelope. ∘ The de-epithelialised skin flap can be used to cover an implant. Nipple sparing mastectomy (NSM) • Similar to SSM, but all the skin and NAC are preserved. • The main concern is local recurrence in the NAC and retroareolar area. ∘ Many advocate biopsy from under the NAC to ensure clear margins. • No randomised trials look at recurrence rates in skin- or nipple sparing techniques. • Case series show 3–6% local recurrence at 5 years, consistent with traditional mastectomy. • NSM can be used for ‘prophylaxis’ and selected therapeutic cases. ∘ When used ‘prophylactically’, it is a risk-reducing rather than cancer-preventing procedure, because some breast tissue remains. • Most suited to patients with tumours <3 cm, located far from the nipple with favourable pathological features and no axillary disease. • Women are counselled about nipple necrosis and potential for local recurrence. • Examples of immediate reconstruction after SSM or NSM: ∘ Subpectoral implant or expander, with inferior pole coverage using ADM placed between the inferior border of pectoralis major and IMF. ∘ Implant or expander placed beneath a latissimus dorsi (LD) flap. 288 ∘ ∘ Chapter 4 Extended latissimus dorsi (ELD) flap with or without subsequent lipofilling. De-epithelialised transverse rectus abdominis myocutaneous (TRAM) or deep inferior epigastric perforator (DIEP) flap. The axilla • The aims of managing the axilla are to: ∘ Stage the axilla ∘ Treat disease in the axilla. • Risk of distant metastases increases with the number of positive nodes. • Metastasis tends to occur to: ∘ Lung ∘ Liver ∘ Bone. Staging the axilla • Pre-operative axillary ultrasound with, if appropriate, FNAC or core biopsy. • If metastatic disease is not confirmed pre-operatively, the axilla should be staged operatively by one of these methods: 1 Sentinel lymph node biopsy (SLNB) using a combined radioisotope and blue dye technique. – This is the preferred technique in early breast cancer. 2 Axillary node sampling. – Removes part of level 1, including at least four lymph nodes. Treatment of the axilla • Indications for axillary clearance: 1 Positive pre-operative FNAC or ultrasound-guided biopsy. 2 Positive SLNB, either macrometastases or micrometastases. • Treatment involves either axillary clearance or radiotherapy. • The significance of isolated tumour cells in lymph nodes is uncertain. ∘ Currently, such patients are regarded as lymph node negative. ∘ Axillary clearance is not recommended. Axillary lymph node clearance • Preferred over radiotherapy as it provides additional staging information. • Levels of the axilla are defined anatomically, based on pectoralis minor: ∘ Level I: inferolateral to pectoralis minor. ∘ Level II: behind pectoralis minor. ∘ Level III: superomedial to pectoralis minor. • Level I–III clearance is effective in controlling regional disease, with recurrence rates of 3–5% at 5 years. • The Edinburgh study showed a similar rate of control is achievable with adjuvant radiotherapy following axillary sampling. • Specific management is determined by local protocols and MDT discussion. The Breast and Chest Wall 289 Adjuvant therapies • Adjuvant systemic treatments reduce risk of recurrence and improve overall survival. Radiotherapy • Indicated in these circumstances: Breast • Primary invasive breast cancer treated with breast conserving surgery. • DCIS treated with breast conserving surgery. • Chest wall radiotherapy for high risk disease, such as: ∘ Large tumour ∘ High grade tumour ∘ ≥4 positive axillary lymph nodes ∘ Involved resection margins. Axilla • Treated by either lymphadenectomy or radiotherapy, but usually not both, unless there is a particularly high risk of regional relapse. Chemotherapy • Lymph node positive breast cancer • Large primary tumour • High grade (grade 3) tumour • ER negative, HER2 positive. • Chemotherapy can be used as: ∘ Neoadjuvant treatment – to reduce the size of tumour prior to surgery. ∘ Adjuvant therapy – to prolong disease-free survival in patients with early breast cancer, especially pre-menopausal women with ER negative tumours. ∘ Treatment for recurrence. Hormonal therapy • All patients with ER positive cancer potentially benefit from hormonal therapy: ∘ Tamoxifen ∘ Aromatase inhibitors (anastrozole, exemestane, letrozole) ∘ Progestogens ∘ Luteinising hormone releasing hormone (LHRH) analogues ∘ Oophorectomy by radiotherapy, laparoscopy or open surgery. Tamoxifen • ER antagonist in breast tissue via its active metabolite, hydroxytamoxifen. • Partial agonist in endometrial tissue. ∘ Linked to endometrial cancer in some women. Aromatase inhibitors • Prevent conversion of androgens to oestrogen in peripheral tissues ∘ They do not stop oestrogen production in the ovaries. 290 Chapter 4 • Considered in postmenopausal women with ER positive tumours. ∘ Not used in pre-menopausal women because decreased oestrogen would stimulate the hypothalamic-pituitary-ovarian axis to increase production. • Can lead to drug-induced bone loss; monitored by dual-energy X-ray absorptiometry (DEXA) scanning. Biological therapy • Trastuzumab (Herceptin) is a monoclonal antibody to HER2 receptor. • Reduces relapse of HER2 positive breast cancer by 50% and mortality by 30%. • Can cause cardiac toxicity. Breast reconstruction Classification Timing • Immediate reconstruction – at the same time as oncological surgery. • Delayed reconstruction – at a later date. • ‘Delayed immediate’ reconstruction has recently been introduced. ∘ Involves preservation of the skin envelope with a tissue expander until the need for adjuvant radiotherapy is known. ∘ If radiotherapy is not required, the expander is removed and reconstruction performed in the ensuing weeks. ∘ If radiotherapy is required, autologous tissue reconstruction can be performed later. Amount of tissue resected • Partial breast reconstruction – after breast conserving surgery. • Complete breast reconstruction – after mastectomy. • Partial breast defects can be reconstructed by: 1 Volume replacement – transferring tissue into the breast. 2 Volume displacement – rearranging breast tissue to fill the defect. Reconstructive options • Oncoplastic techniques. • Breast implant or expander ∘ Combined with flap reconstruction. ∘ Combined with ADM. • Flap reconstruction alone. • Lipomodelling. Oncoplastic techniques Classification • Clough classified oncoplastic techniques: The Breast and Chest Wall ∘ ∘ 291 Level I: loss of ≤20% breast volume. – Reconstruction based on dual plane undermining of the gland followed by glandular reapproximation. – No skin excision is required. – The NAC can be repositioned by de-epithelialising a crescent adjacent to the areola. Level II: loss of 20–50% breast volume. – Reconstruction using more complex procedures based on breast reduction techniques. – These ‘therapeutic mammaplasties’ involve skin excision and breast reshaping. Therapeutic mammaplasty • Uses reduction mammaplasty techniques to extend the role of breast conserving surgery. • Tumour within expected mammaplasty excision areas is removed as part of a normal breast reduction. • Tumour outside normal excision areas requires secondary parenchymal pedicles or extension of the primary pedicle to reconstruct the defect. Other techniques • Local flaps are useful for retroareolar and periareolar tumours. ∘ Examples: Grissoti flap, Batwing or omega flap. Implants or expanders • Implant-based reconstruction is best suited to small breasts (A or B cup). • Requires healthy, non-irradiated overlying skin. • Simple implants or tissue expanders can be used. • Tissue expanders are advantageous because: ∘ They are adjustable. ∘ They create some ptosis if initially over-expanded, then partially deflated. • Implants are placed under pectoralis major whenever possible. • Limitations of subpectoral placement following mastectomy: ∘ Difficulty controlling the lower pole of the pocket during expansion. ∘ Unprotected device coverage by a thin inferior mastectomy flap. ∘ Effacement of the IMF. ∘ Limited control of superior migration of pectoralis major. • Inferolateral support and soft tissue coverage of implants is improved by: ∘ Adjacent local tissues – muscle or fascia. ∘ De-epithelialised skin from a Wise pattern mastectomy. ∘ ADM. • Tissue expanders for breast reconstruction include: Mentor Siltex® Becker expander/implant • Outer lumen filled with silicone gel. • Inner lumen is expandable; filled with saline. 292 Chapter 4 • Silicone gel accounts for 25%, 35% or 50% of the final implant volume, depending on the model used. • Expansion is done percutaneously through a remote port. • When expansion is complete, the remote port is removed by traction. • The saline is retained by a self-sealing valve. • The expander can then be left in place, like a conventional implant. Natrelle® Style 133V series expander • Shaped implant with more projection inferiorly. • Expansion is done via an integral valve in the shell. ∘ The valve is located with a magnet. Implants or expanders combined with flap reconstruction • Implants can be placed under a transposed LD myocutaneous flap. • Advantages: ∘ Relatively easy to perform. ∘ LD flap is reliable. ∘ Well-vascularised tissue is placed over the implant. ∘ Low complication rate. • Disadvantages: ∘ A prosthesis, with all its inherent risks, is required. ∘ Unsightly donor site on the back. Implants combined with acellular dermal matrix • Allows total implant coverage without transfer of autologous tissue. • Best suited to the reconstruction of small to medium-sized breasts. ∘ Complication rate is higher for large breasts, smokers, and obese patients. • ADM is useful: ∘ To extend the subpectoral plane. ∘ To support the implant in its anatomical position. ∘ To define the inferior and lateral folds of the breast. • Can be achieved in a single stage following SSM: 1 A standard subpectoral pocket is developed. 2 A piece of ADM is sutured to the inferior border of the pectoralis major. 3 An implant is placed in this muscle-ADM pocket. 4 The inferior border of the ADM is fashioned around the implant. 5 The pocket is closed by suturing ADM to chest wall, creating the IMF. 6 The space between the ADM and overlying skin is drained. – Collections here delay revascularisation of the ADM, risking infection. – Some also drain the implant pocket. • Two stages may be necessary in these circumstances: ∘ After mastectomy with substantial skin excision. The Breast and Chest Wall 293 ∘ When the viability of mastectomy skin flaps is doubtful. – Involves insertion of a tissue expander as a first stage. • Advantages of reconstruction with ADM: ∘ Reduced soft tissue dissection for inferior pole coverage. ∘ Improved lower pole expansion with better control of breast shape. ∘ Reduced rates of capsular contracture. – A study of 260 patients reported rates of 0.4% after 29 months mean follow-up. • Disadvantages: ∘ Seroma (5%) ∘ Infection (5%) ∘ Reconstructive failure (4%) ∘ Possible need for prolonged drainage. • ADMs are discussed further in ‘Chest wall reconstruction’. Flap reconstruction alone • Flaps are commonly taken from these areas: Back • LD is versatile and robust. The LD muscle only flap • Also known as the latissimus dorsi miniflap (LDMF). Traditional LD myocutaneous flap • Variations in skin paddle design: ∘ Crescentic flaps ∘ Trefoil flaps Extended (autologous) LD (ELD) • Traditional LD flaps do not usually provide sufficient tissue for autologous reconstruction. • ELD flaps incorporate additional adipose tissue from: ∘ Adjacent to the skin island ∘ Covering the whole muscle surface ∘ Scapular area, above the superomedial edge of the muscle ∘ Anterior to the muscle ∘ ‘Love handle’ area above the iliac crest. Thoracodorsal artery perforator (TDAP) flap • Described by Angrigiani in 1995. 294 Chapter 4 • Based on the vertical intramuscular branch of the thoracodorsal artery, which gives two to three cutaneous perforators. • Used alone to reconstruct partial defects, or with an implant for larger defects. Chest wall Intercostal artery perforator (ICAP) flaps • Can be based on: ∘ Vertebral segment – dorsal intercostal artery perforator (DICAP). ∘ Costal segment – lateral intercostal artery perforator (LICAP). ∘ Muscular or rectal segment – anterior intercostal artery perforator (AICAP). • LICAP flaps are useful for partial defects of the lateral breast. Thoracoabdominal advancement flap • Reconstructs the inferior pole with skin of similar colour and texture. • May allow reconstruction without the need for an island skin paddle. Abdomen Pedicled TRAM flap • Supplied by the superior epigastric vessels. • Based on one or both rectus abdominis muscles. ∘ The upper end can be detached from the ribs to facilitate transposition. • Delaying the flap by ligating the deep inferior epigastric vessels may improve flap survival. • Supercharging or turbocharging the flap by anastomosing deep inferior epigastric vessels to the thoracodorsal axis has been suggested. • The donor site is usually reconstructed with synthetic mesh or ADM. • Advantages: ∘ Relatively simple and quick to perform. ∘ Avoids need for an implant. • Disadvantages: ∘ May cause significant donor site morbidity, particularly if both muscles harvested. ∘ Can produce an unsightly bulge in the hypogastric region. ∘ May be difficult to shape and position due to limitations imposed by the pedicle. ∘ High local complication rate, notably fat necrosis, compared to free TRAM. • Proponents of this technique report excellent aesthetic results with minimal donor site morbidity. Free TRAM flap • Based on the deep inferior epigastric artery (DIEA) and vein. • The DIEA usually divides into two major branches, giving perforators in medial and lateral rows: ∘ Lateral branch is dominant in 50%. ∘ Medial branch is dominant in 7%. ∘ Both are equal in 15%. ∘ A single axis with multiple side-branches is seen in 28%. • >90% of the major perforators are within a 6 cm area inferolateral to the umbilicus. The Breast and Chest Wall 295 • The skin paddle is divided into four zones: ∘ Zone 1 – over the ipsilateral rectus abdominis; receives perforators from the DIEA. ∘ Zone 4 – over the extreme opposite side of the abdomen in the territory supplied by the contralateral superficial circumflex iliac artery (SCIA). ∘ There is confusion over whether zone 2 or 3 lies across the midline; this is discussed in detail in Chapter 1. ∘ Zone 4 is relatively poorly perfused and is usually discarded. • Not usually used after abdominoplasty, abdominal liposuction or midline abdominal incisions. Muscle sparing TRAM flap • The whole width of the rectus abdominis need not be harvested. • Limited harvest of rectus abdominis and rectus sheath decreases donor site morbidity. • Include internal oblique when closing the rectus sheath to reduce risk of abdominal bulge. • Nahabedian classified muscle sparing (MS) TRAM flaps: ∘ MS-0 – full width, partial length. ∘ MS-1 – preservation of the lateral segment. ∘ MS-2 – preservation of the lateral and medial segments. ∘ MS-3 (DIEP) – preservation of the entire muscle. Deep inferior epigastric perforator (DIEP) flap • Uses the same skin and soft tissue paddle as a TRAM flap. ∘ However, the flap is based on DIEA perforators rather than the muscle. • Motor nerves are preserved as they traverse horizontally through the muscle. • Advantages: ∘ Less donor site morbidity – the function of rectus abdominis is preserved. ∘ Greater pedicle length. • Disadvantages: ∘ Technically difficult for those unfamiliar with perforator flaps. ∘ May be associated with higher rate of flap complications, particularly fat necrosis. Superficial inferior epigastric artery (SIEA) flap • Uses the same skin and soft tissue as the DIEP flap; however, it does not breach rectus sheath or muscle. • Disadvantages include a small diameter artery and variable anatomy. Omental flap • Laparoscopic harvest of the omental flap, either pedicled or free, for volume replacement has been described. Flank/buttock Superior gluteal artery perforator (SGAP) flap • A perforating vessel is dissected through gluteus maximus to the superior gluteal artery (SGA). 296 Chapter 4 • 5–8 cm of pedicle is available. • Closure of the donor site acts as a unilateral thigh lift. Inferior gluteal artery perforator (IGAP) flap • Based on perforators from inferior gluteal artery (IGA) that pass through gluteus maximus. • The IGAP donor site is more favourable than the SGAP, both in terms of buttock contour and scar concealment in the buttock crease. • A flap based on a deep femoral artery perforator (DFAP) using similar skin and soft tissue has recently been described. Rubens flap • Harvests soft tissue overlying the iliac crest, based on deep circumflex iliac vessels. ∘ This soft tissue pad is prominent in ladies painted by Peter Paul Rubens. • Accurate repair of donor site muscles is important to avoid complications. • Usually used when other autologous options are not available. Lower limb Transverse upper gracilis (TUG) flap • Uses part or all of gracilis with a paddle of skin and fat from the upper medial part of the thigh. • Used to reconstruct small breasts, or for partial breast defects. Lipomodelling • Fat transfer can be used for: ∘ Correction of defects following breast conserving surgery, with or without radiotherapy. ∘ Improvement of soft tissue coverage following implant reconstruction. ∘ Volume augmentation or refinement of autologous reconstruction. ∘ Stimulation of neovascularisation of chronically ischaemic irradiated tissue. ∘ Volume replacement when prosthetic implants have to be removed. • Advantages: ∘ Relatively simple technique to learn. ∘ Performed through stab incisions with minimal scarring. • Disadvantages: ∘ Incomplete fat ‘take’. – Repeat procedures may be required to achieve the desired result. ∘ Fat necrosis, calcification and oil cysts, all of which can lead to unnecessary imaging and biopsies. ∘ Concern about adipose-derived stem cells stimulating cancer growth. – There is no evidence of increased cancer recurrence after lipomodelling. Reconstructing the NAC • Can be done at the same time as breast reconstruction. • However, many surgeons prefer to delay >3 months after breast reconstruction. ∘ Can be difficult to site the NAC at the time of breast reconstruction. • The patient can mark their preferred NAC position in a mirror prior to surgery. The Breast and Chest Wall Nipple reconstruction External nipple prosthesis • Custom-made silicone NAC, stuck on with glue. • Simplest option; can produce realistic results. • Application can be messy and it can fall off. Nipple sharing • Part of the contralateral nipple is used as a composite graft. • Suitable for women with a large nipple on the unoperated breast. Local flaps • Quadripod flap, described by Little (1983). • C-V flap, described by Bostwick (1998). • Double-opposing tab (DOT) flap. • Skate flap, described by Little (1984). ∘ The local flap resembles a skate fish. ∘ Leaves a de-epithelialised donor site around its periphery. ∘ Full thickness skin graft is applied to this area for the areola. • Star flap. ∘ A modified skate flap. ∘ Allows direct closure of the lateral donor sites. ∘ The areola is reconstructed by tattooing. • Tripod ∘ Flaps are shaped like three- or four-bladed propellers. ∘ The centre is drawn up and the propeller blades reconstruct the sides. ∘ Nipple retraction is common post-operatively. Cartilage grafts • Cartilage can be used in two ways: 1 As the sole method of nipple reconstruction. – A lump of cartilage is shaped into a nipple. – Secured in a subcutaneous pocket to give the appearance of a nipple. – Nipples tend to feel firm and unnatural. – Risk of cartilage extrusion, particularly in an irradiated field. 2 To help maintain projection of a local flap nipple reconstruction. – A local flap is wrapped around a central core of cartilage. • Cartilage can be sourced from: ∘ Autologous costal cartilage, removed during exposure of internal mammary artery. – Can be ‘banked’ in the IMF for future use. ∘ Allograft tissue banks. Areola reconstruction Tattooing • Performed at the time of nipple reconstruction or at a later date. • The colour tends to fade with time, necessitating repeat procedures. 297 298 Chapter 4 Full thickness skin grafts • Can be harvested from the contralateral areola during simultaneous contralateral breast symmetrisation. • Alternatively, obtained from non-hairy skin lateral to the labia majora. ∘ Pigmentation of this site approximately matches areola. Chest wall reconstruction • Indicated following: ∘ Tumour resection ∘ Infection ∘ Radiation injury ∘ Trauma. Embryology and anatomy • Ribs, costal cartilages and sternum begin to develop during the 6th week. • Sternum arises from paired longitudinal mesodermal bars. ∘ Fuse cranial to caudal during the 10th week, forming a cartilaginous sternal plate. ∘ Failure of fusion leads to congenital cleft sternum. • 1st–7th ribs extend ventrally to fuse with the sternum in the 9th week. ∘ Known as true ribs. ∘ 8th–10th are false ribs; 11th and 12th are floating ribs. • Intercostal spaces contain three muscles and associated neurovascular bundle (NVB): ∘ External intercostal muscle ∘ Internal intercostal muscle ∘ Innermost intercostal muscle. ∘ NVBs run between internal and innermost muscle layers, along the rib’s inferior border. • Dominant sternal blood supply is from paired internal mammary arteries. • Inspiratory muscles pull the ribcage upwards: ∘ Sternocleidomastoid ∘ Scalenes. • Expiratory muscles pull the ribcage downwards: ∘ Rectus abdominis ∘ External oblique ∘ Internal oblique. • Extensive trauma and tumour resection disrupts chest wall integrity, leading to paradoxical chest movement known as flail chest. • When a flail segment, usually >5 cm, loses continuity with the surrounding chest wall, ventilation becomes inefficient. ∘ Defects <5 cm may be amenable to soft tissue reconstruction alone. Pectus deformities • Occur approximately once every 300 live births. The Breast and Chest Wall 299 • Result from rib cage overgrowth, causing one of these patterns: ∘ Pectus excavatum (concave chest). ∘ Pectus carinatum (convex or pigeon chest). Pectus excavatum • Most common congenital chest wall anomaly. • The sternum is displaced posteriorly; can lie in contact with vertebral bodies. • Associated with scoliosis and Marfan’s syndrome, suggesting a link with connective tissue disorders. • Male:female ratio 3:1. • Most are asymptomatic; some have pulmonary or cardiac compromise. ∘ In such cases, surgery improves ejection fraction but not baseline lung function. • Severity of sternal depression is assessed by the Haller index. ∘ Ratio of transverse to anteroposterior chest diameters. ∘ Normal average index is 2.5; significant pectus deformity scores >3.25. • Can be corrected by: ∘ Ribcage reconstruction. ∘ Insertion of a prosthetic moulage. Reconstruction of the ribcage Ravitch procedure (1949) 1 Perichondrial flaps elevated from costal cartilages. 2 Resection of abnormal costal cartilages; preservation of costochondral junction. 3 Osteotomies of upper and lower sternum, which is mobilised anteriorly. 4 Stabilisation of the sternum in its new position with wires or bars. 5 Pectoralis muscles sutured over the sternum in the midline. • Ravitch’s original description did not use perichondrial flaps or preserve the costochondral junction, resulting in damage to NVBs and rib growth centres. Sternal turnover operation 1 The sternum is mobilised, based on an internal mammary pedicle. 2 Turned over and shaped with anterior osteotomies. 3 Replaced and stabilised with stainless steel wires. Nuss repair (1988) 1 Small incisions are made in the lateral chest wall. 2 A shaped convex metal bar is inserted subcutaneously as far as the sternum. 3 The bar is passed retrosternally under video thoracoscopic guidance, then re-enters the subcutaneous plane on the other side to reach the opposite lateral chest wall. 4 The bar is inserted with its convexity facing posteriorly, then flipped over when correctly positioned. ∘ Results in sternal elevation with subsequent remodelling of ribs and costal cartilages. ∘ Not effective in adults because the chest is less flexible. 300 Chapter 4 Insertion of a prosthetic moulage • Cosmetic treatment using a custom-made prosthesis. • The deformity is imaged and a moulage fabricated from porous polyethylene (Medpor®) or solid silicone, based on 3D reconstructions. • The implant is placed in a subcutaneous pocket. Pectus carinatum • Second most common congenital chest wall abnormality. • Occurs once every 2500 live births; male:female ratio 4:1. • Most patients are asymptomatic; they may complain of pain when lying prone. • Can be corrected by: ∘ Non-operative management with a brace. – Worn 14 hours a day for 2 years; provides continuous anteroposterior compression. – Progressively remodels the chest. ∘ Operative management by modifications of the Ravitch or Nuss procedure. Poland’s syndrome • Described by Alfred Poland (1841) while an anatomy demonstrator at Guy’s Hospital, London. • Originally described absence of sternocostal part of pectoralis major (intact clavicular origin), absence of pectoralis minor, hypoplastic serratus anterior and external oblique. Clinical features • Characterised by unilateral chest wall and upper limb abnormalities. • Variable manifestation from mild to severe. • Affects one in 30,000. • Male:female ratio 2–3:1, but more females seek treatment (for breast asymmetry). • Most cases are sporadic; some cases run in families, suggesting a genetic basis. • Twice as common on the right side in males; rarely bilateral. • Deformities rarely cause functional problems. • Thought to be caused by a vascular developmental anomaly of the subclavian artery in the 6th week. • Associated with Möbius and Klippel–Feil syndromes. ∘ These may be caused by more proximal involvement of the subclavian artery. Chest wall • Absence of the sternocostal head of pectoralis major is pathognomonic. • Absence or hypoplasia of breast and NAC – may be displaced superiorly. • Lack of subcutaneous fat and axillary hair. • Abnormalities of pectoralis minor, infraspinatus, supraspinatus, LD, serratus anterior, external oblique and rectus abdominis. • Abnormalities of the rib cage with possible lung herniation. Upper limb • Short arms • Brachysyndactyly. The Breast and Chest Wall 301 Surgical treatment • Surgery is targeted at cosmetic deformities: Breast • Asymmetry in adolescents can be treated with tissue expanders or expander/implant. ∘ Allows adjustments to match the contralateral breast as it develops. • Once breast development is complete, the expander can be replaced with: 1 Definitive implant covered with LD flap or ADM. 2 Wholly autologous tissue: – Pedicled ipsilateral LD or free contralateral LD. – Omental flap. – TRAM/DIEP flap. – Lipomodelling has been described. Chest • LD can recreate the anterior axillary fold and mask the infraclavicular hollow. ∘ The origin is transposed anteriorly; the humeral insertion is detached and sutured more anteriorly on the bicipital groove. • When multiple ribs are hypoplastic or absent, contralateral costal grafts can be used. ∘ Donor rib periosteum is left behind to encourage regeneration. • Chest implants can be used in males, but may appear unnatural due to lack of muscle cover. Sternal wound infection 1 Superficial infection involves skin, subcutaneous tissue and pectoralis fascia. ∘ Usually eradicated with systemic antibiotics. 2 Deep infection, or mediastinitis, is life-threatening; affects 1–5% of median sternotomies. ∘ Requires aggressive surgical debridement and flap coverage. • Risk factors: ∘ Diabetes ∘ Obesity ∘ Chronic obstructive pulmonary disease ∘ Osteoporosis ∘ Smoking ∘ Use of bilateral internal mammary arteries ∘ Revision operations ∘ Prolonged stay on the intensive care unit. • Success using rigid fixation with plates and screws have led some surgeons to use this method in preference to cerclage wires for sternal repair in high risk patients. Classification of sternal infection • Pairolero classified infected median sternotomy wounds: • Type I ∘ Typically appears within the first week after sternotomy. ∘ Characterised by serosanguinous discharge without evidence of cellulitis, costochondritis or osteomyelitis. – Requires systemic antibiotics and sometimes a single-stage operation. 302 Chapter 4 • Type II ∘ Typically appears between second and fourth weeks after sternotomy. ∘ Characterised by purulent mediastinitis with osteomyelitis ± costochondritis. – Requires debridement and removal of foreign material. – Dead space management with a soft tissue flap. • Type III ∘ Typically appears months to years after sternotomy. ∘ Characterised by chronic draining sinus tracts with costochondritis, osteomyelitis and retained foreign bodies. – Repeated debridements are usually required, followed by dead space obliteration with flaps. Treatment Negative pressure wound therapy (NPWT) • Widespread use of NPWT on sternal wounds has led to: ∘ Reduced need for surgical intervention. ∘ Reduced reoperation rates for persistent infections. ∘ Curtailment of hospitalisation for patients. • NPWT has the following effects on sternotomy wound infections: ∘ Increased local blood flow. ∘ Decreased bacterial count. ∘ Enhanced granulation tissue formation. ∘ Chest stabilisation and improved respiratory function. • Many can be treated with NPWT alone. ∘ Useful for debilitated patients unable to withstand additional surgery. • Factors predicting need for surgical intervention: ∘ Bacteraemia ∘ Wound depth >4 cm ∘ Bone exposure ∘ Sternal instability. • In such cases, NPWT is used as bridging therapy to definitive surgical treatment. Surgery • Pairolero types II and III require surgical debridement of all necrotic and infected soft tissue and bone, with removal of sternal wires or other foreign bodies. • Tissue is submitted for microbiological analysis. • Dead space is filled with well-vascularised tissue: Pectoralis major flap • Can be used in one of two ways: 1 Turnover – based on medial perforators from the internal mammary artery (if intact). 2 Rotation advancement – based on pectoral branches of the thoracoacromial axis. – Can include part of anterior rectus sheath to cover inferior sternum. The Breast and Chest Wall 303 Rectus abdominis flap • Can be used in one of two ways: 1 Muscle only. 2 Myocutaneous. – The skin paddle is oriented vertically, known as a vertical rectus abdominis myocutaneous (VRAM) flap. • Supplied by superior epigastric artery. ∘ This is the continuation of the internal mammary artery. ∘ Flap perfusion may be compromised if internal mammary vessels are used for coronary artery bypass. – In such cases, muscle perfusion may be maintained from the 8th intercostal artery. • Risk of abdominal hernia can be reduced by transposing the muscle while leaving rectus sheath in situ on the abdomen. Omental flap • Based on either of the gastro-epiploic pedicles. • The flap is skin grafted after transposition. • Contours easily into the recesses of a sternal wound. • Has intrinsic immunological function. • Complications related to laparotomy are minimised by laparoscopic harvest. • There is a risk of spreading infection between chest and abdominal cavities. Reconstruction following tumour ablation and trauma • Most agree that chest wall defects >5 cm, or segmental loss of four contiguous ribs, benefit from reconstruction. • Anterior and posterior defects are better tolerated than lateral defects. • Radiotherapy defects may be better tolerated due to the stabilising properties of fibrosis. • Reconstruction should consider skeletal support and soft tissue cover. Skeletal support • Provided by autologous tissue or alloplastic materials. Autologous tissue • Split rib grafts • Iliac crest • Fibula. ∘ Vascularised bone preferred – less resorption, greater rates of union. Alloplastic materials Mesh and composite implants • Polypropylene knitted mesh ∘ Permanent. ∘ Induces fibrovascular infiltration with incorporation into surrounding tissues. 304 Chapter 4 ∘ • • • • • • • Available as single- and double-knit fabrics: – Single-knit (expandable in one direction, rigid in another): Marlex®. – Double-knit (expandable in both directions): Prolene®. Polyester: Mersilene®, Dacron®. Polyglycolic acid: Dexon®. Expanded polytetrafluoroethylene (e-PTFE): Gore-Tex®. Polydioxanone: PDS®. Polyglactin: Vicryl®. Composite techniques allow a construct to be contoured while maintaining rigidity. ∘ Most common is polypropylene mesh and polymethylmethacrylate (PMMA): – Mesh is cut generously, leaving excess to secure the construct to the defect. – PMMA is then added to fill the defect. – A second layer of mesh is placed on the PMMA, creating a sandwich. – Vital structures should be protected because PMMA produces heat as it cures. Mesh repair of previously irradiated or contaminated defects increases risk of infection and implant exposure. Biological materials • Most commonly used are ADMs derived from human or porcine sources. • Most ADMs are gradually revascularised and remodelled into autologous tissue, while maintaining their structural integrity. • More resistant to infection and more readily incorporated into irradiated wounds than synthetics. • Classification of biologicals: ∘ Allografts (human ADM) – From cadaveric dermal allografts. – AlloDerm® is processed human dermis. – Cellular components are chemically and physically removed, while preserving extracellular matrix and basement membrane. – Widely used in the United States, but not currently available in the United Kingdom for this purpose. ∘ Xenografts – Porcine • Permacol® – crosslinked ADM. • Strattice® – non-crosslinked ADM. • Surgisis® – small bowel submucosa. – Bovine • Tutopatch® – pericardium. • Veritas® – pericardium. • Surgimend® – non-crosslinked ADM. Soft tissue cover • Defects not requiring stabilisation can be reconstructed with soft tissue only. • Most reconstructions are accomplished with pedicled flaps: The Breast and Chest Wall 305 Muscle flaps (with or without a skin paddle) • Pectoralis major ∘ For central, supraclavicular, lateral and axillary defects. ∘ Can also be transposed to obliterate intrathoracic dead space. • LD ∘ Useful for large anterior, anterolateral, posterior midline and paramedian defects. • Rectus abdominis ∘ For anterior defects, particularly inferior to the xiphisternum. ∘ The skin paddle can be transversely or vertically oriented. • External oblique ∘ Rarely used; useful for anterolateral chest wall. ∘ Type V blood supply: dominant vessel is deep circumflex iliac artery, with secondary segmental supply from 5th–12th posterior intercostal arteries. ∘ The overlying skin paddle is usually designed as a laterally-based hatchet flap. ∘ Can reach the 2nd intercostal space and up to 5 cm beyond the midline. Other pedicled flaps • Local tissues can be mobilised as fasciocutaneous or perforator flaps. • Omentum can be used for dead space obliteration and soft tissue cover. Free tissue transfer • Indications for free flaps include: ∘ Salvage after the failure of pedicled flaps. ∘ Large defects unreconstructible with pedicled flaps, particularly after radiotherapy. ∘ Defects inaccessible to pedicled flaps. ∘ Intrathoracic deadspace. • Most common free flaps used for chest wall defects: ∘ Tensor fasciae latae – Provides soft tissue cover and thick, strong fascia. ∘ Latissimus dorsi – Including serratus anterior on the same pedicle allows coverage of large defects. ∘ TRAM, VRAM or DIEP – Free transfer is more versatile for insetting than the pedicled equivalent. ∘ Anterolateral thigh flap – Can include fascia lata for support and vastus lateralis for bulk. ∘ Scapular and parascapular flaps – Supplied by the circumflex scapular artery, a branch of the subscapular artery. – Gives a transverse cutaneous scapular branch and vertical parascapular branch. Posterior trunk reconstruction • Most defects result from: ∘ Congenital causes – Spina bifida 306 Chapter 4 ∘ Acquired causes – Trauma – Iatrogenic, following spinal instrumentation – Tumour – Pressure ulcer. • Reconstruction is usually best accomplished with a flap: ∘ Healing by secondary intention or skin grafts is not durable. ∘ Exposed bone or implants require vascularised coverage. Flap options Cervical • Trapezius flap ∘ Raised as muscle or myocutaneous flap. ∘ Based on the superficial branch of transverse cervical artery, from thyrocervical trunk. ∘ Superior fibres of the muscle are left intact to avoid ‘drop shoulder’. Upper thoracic • LD flap • Trapezius flap ∘ Can be raised on posterior intercostal perforators, but rarely required if LD is available. • Scapular or parascapular flap Lower thoracic • LD flap ∘ Can be raised on secondary segmental supply from posterior intercostal arteries. • Intercostal artery perforator flaps ∘ Can be used if muscle is not required for dead space obliteration. • Omentum ∘ Used as a last resort. Lumbar • Lumbar artery perforator flap ∘ Has largely superseded the transverse lumbosacral flap, which is random pattern. ∘ Basing the flap on an identified perforator may be more reliable. • SGAP flap • LD flap ∘ Based on its segmental supply; may not reach inferior lumbar defects. • Omentum. Further reading Breast reduction and mastopexy Benelli L. A new periareolar mammaplasty: the "round block" technique. Aesthetic Plast Surg 1990;14(2): 93–100. The Breast and Chest Wall 307 Hall-Findlay EJ. Vertical breast reduction with a medially-based pedicle. Aesthet Surg J 2002;22(2): 185–94. Hamdi M, Van Landuyt K, Tonnard P et al. Septum-based mammaplasty: a surgical technique based on Würinger’s septum for breast reduction. Plast Reconstr Surg 2009;123(2):443–54. Regnault P. Breast ptosis. Definition and treatment. Clin Plast Surg 1976;3(2):193–203. Robbins TH. A reduction mammaplasty with the areola–nipple based on an inferior dermal pedicle. Plast Reconstr Surg 1977;59(1):64–7. Rohrich RJ, Thornton JF, Jakubietz RG et al. The limited scar mastopexy: current concepts and approaches to correct breast ptosis. Plast Reconstr Surg 2004;114(6):1622–30. Breast augmentation Basu CB, Jeffers L. The role of acellular dermal matrices in capsular contracture: a review of the evidence. Plast Reconstr Surg 2012;130(5 Suppl 2):118S–24. Cunningham B. The Mentor Core Study on silicone MemoryGel breast implants. Plast Reconstr Surg 2007;120 (7 Suppl 1):19S–29. de Jong D, Vasmel WL, de Boer JP et al. Anaplastic large-cell lymphoma in women with breast implants. JAMA 2008;300(17):2030–5. Khouri RK, Eisenmann-Klein M, Cardoso E et al. Brava and autologous fat transfer is a safe and effective breast augmentation alternative: results of a 6-year, 81-patient, prospective multicenter study. Plast Reconstr Surg 2012;129(5):1173–87. Little G, Baker JL Jr., Results of closed compression capsulotomy for treatment of contracted breast implant capsules. Plast Reconstr Surg 1980;65(1):30–3. Medicines and Healthcare products Regulatory Agency. Information for women considering breast implants. 2012. http://www.mhra.gov.uk (last accessed 18th July 2014). Spear S. Augmentation/mastopexy: “surgeon, beware”. Plast Reconstr Surg 2003;112(3):905–6. Spear SL, Carter ME, Ganz JC. The correction of capsular contracture by conversion to “dual-plane” positioning: technique and outcomes. Plast Reconstr Surg 2003;112(2):456–66. Spear SL, Murphy DK. Allergan Silicone Breast Implant U.S. Core Clinical Study Group. Natrelle round silicone breast implants: core study results at 10 years. Plast Reconstr Surg 2014;133(6):1354–61. Tebbetts JB. Dual plane breast augmentation: optimizing implant-soft-tissue relationships in a wide range of breast types. Plast Reconstr Surg 2001;107(5):1255–72. Tebbetts JB, Adams WP. Five critical decisions in breast augmentation using five measurements in 5 minutes: the high five decision support process. Plast Reconstr Surg 2006;118(7 Suppl):35S–45. Tuberous breast von Heimburg D. Refined version of the tuberous breast classification. Plast Reconstr Surg 2000;105(6): 2269–70. von Heimburg D, Exner K, Kruft S et al. The tuberous breast deformity: classification and treatment. Br J Plast Surg 1996;49(6):339–45. Pacifico MD, Kang NV. The tuberous breast revisited. J Plast Reconstr Aesthet Surg 2007;60(5):455–64. Gynaecomastia Simon BE, Hoffman S, Kahn S. Classification and surgical correction of gynecomastia. Plast Reconstr Surg 1973;51(1):48–52. Webster JP. Mastectomy for gynecomastia through a semicircular intra-areolar incision. Ann Surg 1946; 124(3):557–75. 308 Chapter 4 Breast cancer and reconstruction Association of Breast Surgery at Baso 2009. Surgical guidelines for the management of breast cancer. Eur J Surg Oncol 2009;35(Suppl 1):1–22. Chan CW, McCulley SJ, Macmillan RD. Autologous fat transfer – a review of the literature with a focus on breast cancer surgery. J Plast Reconstr Aesthet Surg 2008;61(12):1438–48. Dewis R, Gribbin J. Breast Cancer: Diagnosis and Treatment. An Assessment of Need. NICE Clinical Guidelines, No. 80–81S. Cardiff, UK: National Collaborating Centre for Cancer, 2009. Forrest AP, Everington D, McDonald CC et al. The Edinburgh randomized trial of axillary sampling or clearance after mastectomy. Br J Surg 1995;82(11):1504–8. Galimberti V, Zurrida S, Zanini V et al. Central small size breast cancer: how to overcome the problem of nipple and areola involvement. Eur J Cancer 1993;29A(8):1093–6. Jeevan R, Cromwell D, Browne J et al. National Mastectomy and Breast Reconstruction Audit 2011. Leeds: The NHS Information Centre, 2011. http://www.hscic.gov.uk (last accessed 18th July 2014). Nahabedian MY. Acellular dermal matrices in primary breast reconstruction: principles, concepts, and indications. Plast Reconstr Surg 2012;130(5 Suppl 2):44S–53. Chest wall reconstruction Arnold PG, Pairolero PC. Chest-wall reconstruction: an account of 500 consecutive patients. Plast Reconstr Surg 1996;98(5):804–10. Blanco FC, Elliott ST, Sandler AD. Management of congenital chest wall deformities. Semin Plast Surg 2011;25(1):107–16. Fokin AA, Robicsek F. Poland’s syndrome revisited. Ann Thorac Surg 2002;74(6):2218–25. Hester TR Jr., Bostwick J 3rd., Poland’s syndrome: correction with latissimus muscle transposition. Plast Reconstr Surg 1982;69(2):226–33. Mahabir RC, Butler CE. Stabilization of the chest wall: autologous and alloplastic reconstructions. Semin Plast Surg 2011;25(1):34–42. Singh K, Anderson E, Harper JG. Overview and management of sternal wound infection. Semin Plast Surg 2011;25(1):25–33. CHAPTER 5 The Upper Limb CHAPTER CONTENTS Embryology, 309 Congenital deformities, 311 Hand trauma, 329 Hand infections, 351 Complex regional pain syndrome (CRPS), 355 Nerve compression, 357 Traumatic brachial plexus injury, 371 Obstetric brachial plexus palsy, 382 Tendon transfers, 384 Dupuytren’s disease, 388 Tumours, 396 Arthritis, 401 Miscellaneous tendinopathy, 417 Further reading, 419 Embryology Developmental anatomy • Upper limb bud appears in the flank of the embryo on day 26. • Consists of a core of lateral plate mesoderm covered by ectoderm. ∘ This mesoderm will differentiate into bone, cartilage and tendon. • Ectoderm thickens at the tip of the bud in the anteroposterior (AP) axis to form the apical ectodermal ridge (AER). ∘ In the embryo, the AP axis is analogous to the radio-ulnar axis. • The limb bud is initially supplied by a capillary network. • This coalesces into a main stem artery that drains into a marginal vein. ∘ Artery becomes the subclavian-axillary-brachial axis. ∘ Vein becomes the basilic-axillary-subclavian axis. • The brachial artery branches into interosseous and median arteries. ∘ The median artery provides the main blood supply to the hand. ∘ It is usually replaced by ulnar and radial arteries around day 44. ∘ Regresses to provide the blood supply of the median nerve. • By day 33 a paddle-shaped hand is present. Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 309 310 Chapter 5 • Prechondrogenic condensations of mesenchyme appear where skeletal elements will form. • Around day 36, nerve trunks enter the arm. • Somitic mesoderm invades the limb and aggregates into dorsal and ventral masses. ∘ These differentiate into myoblasts that become muscle. • By day 42, digital rays are present and the hand assumes a webbed appearance. • During the 7th week, upper limbs rotate 90∘ laterally to bring the palm anteriorly. • At the same time, the elbow begins to flex. • During this period, ossification begins and digital separation occurs. ∘ This occurs by the apoptosis of tissue between finger rays. • By the 8th week, the upper extremity resembles a miniature adult upper limb. Mechanisms of development • Our understanding comes largely from transplanting tissue within chick embryos. • Discrete cell signalling pathways establish the three axes of limb development: Proximodistal axis • Controls how the limb differentiates into a shoulder proximally but fingers distally. • The critical area is the AER. ∘ Resection of the AER results in a truncated limb. ∘ Earlier resection results in more proximal limb truncation. ∘ Grafting of the AER elongates limbs of chick embryos. • AER produces fibroblast growth factors (FGFs), most importantly FGF 2, 4 and 8. Anteroposterior axis • Controls how an ulna and little finger develop on one side but a radius and thumb on the other. • The critical area is the zone of polarising activity (ZPA). ∘ ZPA is a cluster of mesenchymal cells in the posterior limb bud margin. ∘ Grafting of ZPA cells to the anterior limb margin induces mirror image duplication. • The ZPA produces Sonic hedgehog (Shh). ∘ Higher concentrations of Shh result in more posterior (ulnar) digits being formed. • Cells of the AER and ZPA are interdependent: ∘ FGFs from the AER are required for Shh expression. ∘ Shh signal is required to maintain AER integrity. • This may explain why loss of elements often occurs in both AP and proximodistal axes. Dorsoventral axis • Controls how the limb differentiates into a dorsal and palmar surface. • The critical area is non-AER ectoderm. ∘ Removing and replacing ectoderm from a chick limb bud, having reversed its dorsoventral polarity, will produce a reversal in the polarity of the underlying mesoderm. • Wnt-7a is a protein encoded by the WNT7A gene. ∘ WNT7A is expressed specifically by dorsal limb ectoderm and determines dorsal limb identity, e.g. fingernails. ∘ Wnt-7a activates expression of LIM homeodomain factor Lmx1. The Upper Limb 311 • In contrast, ventral ectoderm expresses engrailed-1 (en-1), which inhibits Wnt-7a and restricts its actions to the dorsal ectoderm. • Failure of these systems produces duplicated palms or circumferential fingernails. Congenital deformities Classification • Swanson’s classification is widely accepted. • The following account does not include the full hierarchy of the classification: I. Failure of formation of parts (arrest of development) A. Transverse arrest • Shoulder, arm, elbow, forearm, wrist, carpal, metacarpal, phalanx. B. Longitudinal arrest • Radial ray • Ulnar ray • Central ray (cleft hand) • Intersegmental (intercalated) type of longitudinal arrest. II. Failure of differentiation (separation) of parts A. Soft tissue involvement • Arthrogryposis • Cutaneous syndactyly • Camptodactyly • Thumb-in-palm deformity B. Skeletal involvement • Clinodactyly • Osseous syndactyly • Symphalangia • Elbow, forearm and carpal synostosis. C. Congenital tumorous conditions III. Duplication • Whole limb, humerus, radius, ulna • Mirror hand • Radial polydactyly (preaxial polydactyly) • Central polydactyly • Ulnar polydactyly (postaxial polydactyly). IV. Overgrowth • Whole limb • Macrodactyly. 312 Chapter 5 V. Undergrowth • Whole limb, whole hand • Brachymetacarpia • Brachysyndactyly, with or without absence of pectoral muscle • Brachydactyly. VI. Congenital constriction band syndrome • Constriction band either with or without lymphoedema • Acrosyndactyly • Intrauterine amputation. VII. Generalised skeletal abnormalities • Chromosomal abnormalities • Other generalised abnormalities. • This classification is based on work published in the 1960s and 1970s. • As understanding of the pathogenesis has progressed, the shortcomings of the classification have become evident. • Differentiating between transverse arrest, brachysyndactyly and symbrachydactyly (previously termed atypical cleft hand) can be difficult: ∘ Some consider brachysyndactyly and symbrachydactyly to be the same entity, on a continuum with transverse arrest, rather than classified as undergrowth. ∘ Buck-Gramcko wrote in 1999: ‘The Congenital Committee of the IFSSH has recognized the problem of symbrachydactyly classification since 1995 but has not come to any conclusions and recommendations’. ∘ Swanson himself noted: ‘Brachysyndactyly could be placed in either Category I or II because of some of its features … Its most obvious failure clinically, however, is hypoplasia or undergrowth, and for that reason it is placed in Category V’. Failure of formation Transverse arrest • Can occur at any level. • Most common at the junction of proximal and middle thirds of the forearm. • Treatment is usually non-surgical with a prosthesis from 6 months. ∘ Children with unilateral deformities tend to discard the prosthesis. • When there are metacarpal remnants, these may be amenable to: ∘ Distraction lengthening ∘ Free phalangeal or toe transfer. Longitudinal arrest Radial deficiency • A spectrum of abnormalities affecting the radial side of the forearm. • Radius, radial carpus, thumb, tendons, ligaments, muscles, nerves and blood vessels can all be involved. • Most common type of longitudinal failure of formation, affecting one in 55,000 live births. The Upper Limb 313 • Usually manifests as hypoplastic or absent radius with radial deviation of the hand – formerly known as ‘radial club hand’. Associated abnormalities • Up to 40% of unilateral and 77% of bilateral cases are syndromal. • All require assessment by a paediatrician and geneticist. • Associated conditions include: ∘ Holt–Oram syndrome – Cardiac septal defects and various upper limb malformations. – Autosomal dominant inheritance. ∘ VACTERL association – Vertebral anomalies, Anal atresia, Cardiac defects, Tracheal anomalies (including tracheo-oesophageal fistula), Esophageal atresia, Renal and radial abnormalities, other Limb abnormalities. ∘ TAR syndrome – Thrombocytopaenia-Absent Radius; autosomal recessive inheritance. – The thumb is usually present in TAR. ∘ Fanconi’s anaemia – Rare autosomal recessive cause of bone marrow failure. – Radial deficiency affects 40%; aplastic anaemia develops around 6 years. – Fatal without bone marrow transplantation. Clinical features • Short forearm, bowed on the radial side. • Complete or partial absence of the radius, which may be replaced by a fibrous anlage. ∘ [In German, Anlage (pronounced ann-lager), means ‘foundation’ or ‘plan’] • Radially deviated hand with reduced passive wrist motion. • Radial skin deficiency with relative excess on the ulnar side. • Hypoplastic or absent thumb. • Flexion contracture and stiffness of the radial digits. • Elbow stiffness, which may be due to bony fusion (synostosis). • Proximal muscles of the arm and shoulder can also be affected. • Bilateral and unilateral involvement are equally common. ∘ Involvement of the contralateral limb may be subtle and asymmetric. Classification • Classified into four types by Bayne and Klug: ∘ Type I: Short distal radius ∘ Type II: Hypoplastic radius ∘ Type III: Partial absence of the radius ∘ Type IV: Total absence of the radius. Treatment • Based on age, severity and degree of functional deficit. 314 Chapter 5 Manipulation • Physiotherapy to elbow and wrist prevents progressive stiffness and maintains range of motion. ∘ Parents should do this at least twice a day. • Mildest deformities can be treated with physiotherapy alone. • Splintage is difficult to apply and adds little benefit. • External fixators are widely used to distract radial soft tissues prior to surgery. Surgery • Performed around 12 months, but this varies. • The following abnormalities may be found: ∘ Variable deficiencies of the radial forearm structures. ∘ Aberrant radial wrist extensors and extrinsic thumb muscles. ∘ Absence of the radial artery. ∘ Absence of the radial nerve below the elbow. ∘ Median nerve is always present – often the most radial structure of the wrist. • Centralisation ∘ Carpus is repositioned over the ulna and stabilised with a pin through the third metacarpal and carpus into the ulna. – Usually requires extensive soft tissue release. ∘ Radial wrist extensors are transposed onto extensor carpi ulnaris (ECU) to counter the radial deforming force. ∘ Some recommend transposing redundant skin from the ulnar wrist to release the radial contracture. • Radialisation ∘ Scaphoid is placed over the ulna and secured with a pin through the second metacarpal. ∘ Transfer of flexor carpi radialis (FCR) and flexor carpi ulnaris (FCU) to the ulnar carpus or fifth metacarpal decreases the radial deforming force. • Microvascular joint transfer ∘ Centralisation and radialisation are associated with high recurrence rates. ∘ They also have the potential to injure the distal ulnar physis, causing growth arrest. ∘ Vilkki described vascularised transfer of the second MTPJ to avoid these problems. ∘ It is technically demanding and not widely practised. • Pollicisation of the index finger ∘ Indicated for cases with a severe hypoplastic thumb. ∘ Aims to reproduce thumb function by shortening and rotating the index finger. 1 A radial palmar incision is made, creating skin flaps at the base of the index finger. • Allows subsequent creation of a first webspace. 2 Ulnar digital nerve is mobilised by interfascicular dissection of the common digital nerve to the index-middle finger web. 3 Radial digital artery to the middle finger is ligated and divided. 4 Interossei are elevated from the index finger metacarpal. 5 Index metacarpal is removed, except for its head, which forms the new trapezium. • The epiphysis is resected to prevent subsequent growth. The Upper Limb 315 6 Metacarpal head is rotated 160∘ – this will subsequently relax to 120∘ , ideal for opposition. • Secured with K wires in 40∘ of palmar abduction with metacarpophalangeal joint (MCPJ) hyperextended. 7 The length of metacarpal removed is measured and a similar length of flexor and extensor tendon is excised. • Some do not remove tendon because they are said to shorten over time. 8 Rebalancing the intrinsics is essential: • First dorsal interosseous is sutured to the radial lateral band to become abductor pollicis brevis (APB). • First palmar interosseous is sutured to the ulnar lateral band to become adductor pollicis. • Extensor indicis proprius (EIP) acts as extensor pollicis longus (EPL). • Extensor digitorum communis (EDC) to the index finger acts as the abductor pollicis longus (APL). • Many children require opponensplasty between 5 and 8 years. Ulnar deficiency • One-tenth as common as radial deficiency. • Spectrum of abnormalities, from hypoplasia of ulnar digits to absence of ulna. • Hand and carpus are always affected: missing digits, syndactyly, thumb abnormalities. • It differs from radial deficiency: ∘ The wrist is stable but elbow unstable. ∘ Associated more with musculoskeletal abnormalities than cardiovascular. ∘ Total absence is most common for the radius; partial absence is most common for the ulna. ∘ Less likely to occur as part of a syndrome. Classification • Classified by Bayne into four types: ∘ Type I: hypoplasia of the ulna (both proximal and distal epiphyses present) ∘ Type II: partial aplasia of the ulna (absence of the distal or middle third) ∘ Type III: total aplasia of the ulna ∘ Type IV: radiohumeral synostosis. Treatment • Depends on the nature and severity of the deformity; there is no consensus view. • Release of the fibrous anlage with realignment of the carpus and forearm. ∘ The anlage, present in types II and IV, is claimed to increase ulnar deviation of the hand and ulnar bowing of the radius as the child grows. • Hand function is improved as required by: ∘ Separating any syndactyly ∘ Deepening the first webspace ∘ Thumb reconstruction: opponensplasty, rotation osteotomy or pollicisation. • Rotation osteotomy of the humerus improves hand position for some cases of radiohumeral synostosis. 316 Chapter 5 Central deficiency • Also known as cleft hand. • Historically, cleft hand was divided into typical and atypical types. Typical cleft hand • V-shaped cleft in the centre of the hand; one or more digits may be absent. • Often bilateral; frequently involves both the hands and feet. • Family history is common – inheritance is autosomal dominant. • May form part of a syndrome, e.g. split-hand/split-foot, EEC (ectrodactyly, ectodermal dysplasia, facial clefts). • First webspace often narrowed. • ‘Transverse metacarpals’ can further widen the cleft over time. • Phalanges may have longitudinally bracketed epiphyses or duplications. Classification of typical cleft hand • The Manske and Halikis classification focuses on the first webspace: ∘ Type I: normal web ∘ Type IIA: mildly narrowed web ∘ Type IIB: severely narrowed web ∘ Type III: syndactylised web (first webspace is obliterated) ∘ Type IV: merged web (index ray suppressed; first webspace merged with the cleft) ∘ Type V: absent web (thumb elements suppressed; first webspace not present). Treatment of typical cleft hand • Patients usually have good hand function. • Labelled ‘a functional triumph, but a social disaster’. • Early surgery may be required to prevent progressive deformity: 1 To separate syndactyly between unequal digits, especially thumb-index. 2 To remove transverse bones that would worsen the cleft with growth. • Other surgery can be postponed until between 1 and 2 years: 1 Release or reconstruction of the first webspace. 2 Closure of the cleft. – Snow-Littler technique: palmar-based flap from the cleft is transposed to the first web. – Miura and Komada method: simpler – palmar and dorsal flaps are redraped. – 2nd metacarpal is transferred to the 3rd metacarpal base and secured with K wires. • Transposing the 2nd metacarpal at the level of its neck may preserve the adductor pollicis origin from the 3rd metacarpal. – Deep transverse metacarpal ligament is reconstructed using adjacent A1 pulleys, unfolded towards one another. 3 Creation of a thumb for cases where it is absent. – Pollicisation or, if no radial ray available, free toe transfer. 4 Addressing the foot deformity – Only indicated when there are difficulties fitting footwear. The Upper Limb 317 – The fibular ray is the most important for weight bearing and gait. – The tibial toe can usually be transferred to the hand if required. Atypical cleft hand • Now known as symbrachydactyly. • Characterised by short vestigial digits, like small nubbins. ∘ Often have vestigial nails. • May occur with Poland’s syndrome. • Symbrachydactyly, in contrast to central ray deficiency: ∘ Is usually unilateral ∘ Seldom involves the feet ∘ Is not usually associated with a family history. • Its place within Swanson’s classification is controversial. ∘ Probably not a longitudinal central ray deficiency. Classification of symbrachydactyly • Blauth and Gekeler classify symbrachydactyly into four types: ∘ Short finger type – a thumb and four short stiff digits ∘ Oligodactylic type – central aplasia – the classic ‘atypical cleft hand’ ∘ Monodactylic type – a thumb and four nubbins ∘ Peromelic type – complete absence of fingers and thumb. Treatment of symbrachydactyly • Short finger type usually have excellent function. ∘ Some may require syndactyly release or free phalangeal bone transfer. • Oligodactylic type achieve pincer grip with thumb and little finger. ∘ Metacarpal rotation osteotomy can improve the position of these digits. • Some oligodactylic and monodactylic types may be suitable for toe-to-hand transfers if metacarpals and extrinsic tendons are present. • Peromelic type is difficult to reconstruct due to lack of proximal structures. Intersegmental deficiency • ‘Phocomelia’ is the historical term for intercalated deficiency of the upper limb. ∘ Phocomelia derives from the Greek, meaning ‘seal limb’, i.e. a flipper. • The hand is always present. • Prevalent in the 1960s due to the use of thalidomide for hyperemesis gravidarum. ∘ Worldwide, thalidomide is still used as an anti-angiogenic drug to treat leprosy and myeloma. • Frantz and O’Rahilly classify phocomelia into three types: ∘ Type I: complete – the hand is directly attached to the trunk ∘ Type II: proximal – the forearm and hand are attached to the trunk ∘ Type III: distal – the hand is attached to the humerus at the elbow. • A prosthesis may be required if the hand cannot reach the mouth. • Surgery, usually to stabilise the limb, is rarely indicated. 318 Chapter 5 Failure of differentiation Soft tissue failures of differentiation Syndactyly • Derived from the Greek, ‘syn’ – ‘together’ and ‘dactylos’ – ‘digit’. • May result from failure of apoptosis in interdigital tissue. • Occurs once every 2000 live births. • One of the two most common upper limb malformations, the other being polydactyly. • 20% have a family history (autosomal dominant); 50% are bilateral. • Twice as common in males. • Most common in Caucasian races. • May be associated with other deformities such as Apert’s and Poland’s. Classification • Complete – digits fused to the level of the tips. • Incomplete – fusion does not extend to the tips. • Simple – only soft tissue connections between the digits. • Complex – soft tissue and bony connections between the digits. • Complex complicated – associated accessory digits or phalanges within the syndactyly. • Acrosyndactyly – characterised by fused distal parts of the fingers. ∘ Small spaces (fenestrations) are always present between the digits proximally. ∘ Pathogenesis of acrosyndactyly is different from other forms of syndactyly: – Distal parts of the digits are thought to re-fuse due to constriction ring syndrome. Clinical features • Middle-ring finger web is most commonly affected – 58% of cases. ∘ 27% ring-little finger web. ∘ 14% middle-index web. ∘ 1% thumb-index web. • Nail fusion (synonychia) with loss of the paronychial fold suggests synostosis of the distal phalanges. • Associated limb, chest wall and foot abnormalities. • Radiographs may show synostosis, synpolydactyly or other anomalies. • More complex syndactyly is associated with tendon, nerve and vessel anomalies. • Variable vascular anatomy and distal bifurcation of common digital vessels can lead to vascular compromise following separation. Indications for surgical correction • Not usually performed before 1 year of age. • Aim to have separation completed by school age. • Indications for earlier surgery, as soon as the child is deemed fit, include: ∘ Syndactyly of thumb-index or little-ring fingers. – Released early because length discrepancy can cause deformity with growth. The Upper Limb 319 Principles of surgical correction • Aim to separate the digits, provide a lined commissure, create minimal scarring. • The normal webspace slopes 45∘ dorsal to palmar and runs from the metacarpal heads to the midpoint of the proximal phalanx. • Most techniques share the following principles: ∘ Release only one side of a digit at a time to avoid jeopardising finger vascularity. ∘ If multiple digits are involved, surgery is staged: – First stage: release thumb-index and middle-ring fingers. – Three months later: release index-middle and ring-little fingers. ∘ The bifurcation of the digital NVB may be distal to the position of the new webspace. – Web release is therefore limited to the level of the bifurcation, unless: • The other side of the finger is not operated on, allowing the bifurcation to be divided. • There is definitely a second digital artery to supply the finger. – Alternatively, vein grafts can be used to lengthen the artery. ∘ The nerve can be separated by interfascicular dissection. ∘ Linear incisions are avoided due to the risk of scar contracture. ∘ The web is reconstructed with proximally based dorsal or volar flaps. – Skin grafts in the web spaces can result in web creep. ∘ Dorsal and volar interdigitating flaps close defects along the borders of the digits. – Full thickness skin grafts may be required to resurface residual raw areas. ∘ Mild first web syndactyly can be released with local flaps, e.g. four-flap Z-plasty. ∘ Severe syndromal syndactyly may require transposition flaps, tissue expansion or distant/free flaps. ∘ Hyponychial interdigitating flaps, described by Buck-Gramcko, can reconstruct the lateral nail fold. • Complications include: vascular compromise, infection, dehiscence, graft loss. ∘ The commissure may be pulled distally by scar contraction (web creep). ∘ Scars may cause joint contracture. ∘ Joint instability, due to insufficient collateral ligaments. Camptodactyly • From the Greek, meaning ‘bent finger’. • Characterised by progressive flexion deformity of the proximal interphalangeal joint (PIPJ). • Often bilateral; most commonly involves the little finger. • Affects <1%. • Virtually anything crossing the volar aspect of the finger may cause camptodactyly. ∘ Most commonly an abnormal lumbrical insertion or short flexor digitorum superficialis (FDS). • Examining PIPJ extension with the MCPJ alternately flexed and extended can differentiate between intrinsic and extrinsic causes. 320 Chapter 5 • Function is rarely affected; treatment is usually sought for the appearance. • Bone and joint abnormalities on x-ray are usually secondary changes rather than the primary cause. Classification • Type I: presents during infancy; most common type. Most do not require treatment. • Type II: presents during preadolescence (age 7–11); affects girls more than boys. ∘ Often progresses to a severe deformity. • Type III: severe type associated with various syndromes. Treatment • The majority of cases with contractures <40∘ are treated conservatively. ∘ Involves stretching exercises, splinting and serial casting. • Difficult to correct surgically. • Radiological signs that indicate the deformity may be difficult to correct: ∘ Narrowing of the joint space ∘ Indentation of the neck of the proximal phalanx ∘ Flattening of the head of the proximal phalanx. • Surgical options: ∘ Exploration and release of any tethering structures. ∘ FDS tendon transfer to the extensor surface. ∘ Angulation osteotomy. ∘ Arthrodesis. Trigger thumb • ‘Congenital’ trigger thumb is a misnomer because it is not found in newborns. ∘ Also, the thumb does not usually ‘trigger’ – it is typically fixed in flexion. • Prevalence at 1 year is 3 per 1000; bilateral in up to 30%. • Trigger thumb likely develops with postnatal growth. • Notta’s nodule is always present. ∘ May be palpable within flexor pollicis longus (FPL) just proximal to the A1 pulley. • Trigger finger is less common than trigger thumb. ∘ The pathology may lie at the A1 pulley and/or at the decussation of FDS. Treatment • Observation is reasonable under 1 year of age. ∘ 30% resolve spontaneously within the first year. • Joint contractures do not occur if release is delayed until age 3. • When to operate is agreed between surgeon and parents, considering the risks and benefits. • Surgical treatment involves release of the A1 pulley. Clasped thumb • A spectrum of congenital thumb abnormalities ranging from deficiency of thumb extensor mechanism to more severe problems with thenar muscles and first web contracture. ∘ Also associated with arthrogryposis. The Upper Limb 321 • Diagnosis often delayed because infants hold thumbs in their palms for the first 3 months. • Extension lag of the MCPJ differentiates it from trigger thumb. Treatment • Goal of treatment is to restore the thumb’s ability to grasp. • Initial treatment is splintage in extension for up to 6 months. ∘ Effective when commenced <1 year. • Surgery indicated if splintage fails, or the child is older than 2 years. • Adduction contracture requires release of the first web. • Tendon transfers or grafts to the extensor mechanism for severe deformities that remain passively correctable. • Joint fusions for malpositioned fixed deformities. Arthrogryposis • From the Greek, meaning ‘curved joint’. ∘ Also known as arthrogryposis multiplex congenita. • A syndrome of non-progressive joint contractures present at birth. • Spectrum of severity and many different types, including clasped thumb and windblown hand. • Most common types occur sporadically; can be part of Freeman–Sheldon syndrome. • Proposed aetiology is lack of motion during fetal development, leading to joint contractures. ∘ Can be caused by neuromuscular abnormalities, restricted intrauterine space, vascular insufficiency or maternal illness. ∘ There may be reduced numbers of spinal anterior horn cells. Clinical findings • Congenital contractures, usually symmetrical and bilateral. • Adduction and internal rotation of the shoulders. • Elbows fixed in extension with pronated forearms. • Wrists flexed with the hand in ulnar deviation. • Flexed and stiff digits. • Lack of subcutaneous tissue and muscle wasting. • Thin, waxy skin with no joint creases. • Lower limb involvement is an important consideration. Treatment • Goals of treatment: 1 Independent function for feeding and perineal care. 2 Maintaining or increasing passive and active motion. 3 Preserving bimanual function. • A team approach is required, with the help of adaptive equipment. • Treatment begins early: ∘ Dynamic and static splintage. ∘ Passive stretching and range of motion exercises. 322 Chapter 5 • Surgical intervention is controversial; indicated for specific functional problems: 1 Recalcitrant elbow contracture release. 2 Restoration of elbow flexion with muscle transfers. – Examples include partial triceps, pectoralis major or free gracilis. 3 Distraction lengthening of wrist soft tissues. – Dorsal wedge osteotomy of the radius and tendon transfer may allow use of a keyboard. 4 Reconstruction of a clasped thumb. Skeletal failures of differentiation Clinodactyly • From the Greek, meaning ‘inclined finger’. • Characterised by curvature of a digit in the radio-ulnar plane. • Associated with many syndromes, including 25% of Down’s syndrome. • Most commonly affects the little finger. • Usually turns the fingertip towards the middle finger. • The cause is usually deformity of the middle phalanx – often a triangular shaped delta phalanx. ∘ Formed by a J- or C-shaped epiphysis, which extends onto the lateral side of the phalanx. ∘ Also known as a longitudinal bracketed epiphysis. • Growth from the longitudinal arm of the epiphysis results in abnormal lateral growth of the bone. • Kirner’s deformity should not be confused with clinodactyly: ∘ Progressive palmar-radial curvature of the distal phalanx, usually the little finger. ∘ Develops in adolescence; can be inherited or occur sporadically. ∘ Almost never affects function. Treatment • The majority of cases are mild and should be discouraged from surgery. • Surgery considered if function is limited. ∘ This should be delayed until skeletal maturity. • Wedge osteotomy corrects the angulation. ∘ Usually an opening wedge because the finger is often short. ∘ Exchange wedge osteotomy inserts the wedge excised from the longer side of the phalanx into an opening wedge osteotomy on the shorter side. • Soft tissue shortage may require Z-plasty or local flaps. • Resection of the epiphyseal bracket with interposition fat graft was described by Vickers. Symphalangism • Congenital fusion of one phalanx to another within the same digit. • Associated with a number of other conditions, including: ∘ Syndactyly ∘ Apert’s syndrome The Upper Limb 323 ∘ ∘ Poland’s syndrome Radial longitudinal deficiency. • Flexion and extension creases over the affected joints are absent. • Radiological changes: ∘ Short middle phalanges ∘ Poorly developed joints and epiphyses. Treatment • Managed conservatively with physiotherapy and splintage. • Osteotomy or arthrodesis is considered once skeletally mature. Synostosis • Abnormal fusion of two bones. • Can occur at any site where two bones are adjacent to one another. • Synostosis between phalanges occurs in complex syndactyly. • Carpometacarpal, intercarpal and radiocarpal synostosis seldom require surgery. • Radio-ulnar synostosis poses functional problems if both forearms are affected. • Rotational osteotomy through the synostosis is performed around 5 years of age. ∘ Aims to fix the dominant limb in 10∘ –20∘ pronation and the other midprone. ∘ Allows eating, writing, bimanual manipulation and perineal care. Duplication • Can involve the whole limb or any part of the limb. • Polydactyly is when more than five digits are present in a hand. ∘ One of the most common upper limb malformations. ∘ Extra digits may be located on the ulnar border, centre or radial border. Ulnar polydactyly • Also known as postaxial polydactyly. • Usually an autosomal dominant trait with variable penetrance. • Often associated with syndromes in Caucasians. ∘ Other systemic abnormalities should be sought. • Often bilateral; commoner in boys. • Incidence is 1:2000 among Caucasians; 1:150 among African Americans. • Stelling classification of polydactyly: ∘ Type I: soft tissue mass without skeletal structure. ∘ Type II: digit contains all normal components and articulates with a normal or bifid metacarpal or phalanx. ∘ Type III: complete digit with metacarpal. Treatment • Type I: excised under local anaesthetic in the first few weeks of life. ∘ Avoids a residual nubbin resulting from simple ligation. 324 Chapter 5 • Types II and III: surgical excision and reconstruction of soft tissue elements: ∘ Attachments of the ulnar collateral ligament (UCL) and abductor digiti minimi (ADM) are transferred to the adjacent finger. Central polydactyly • Rarest form of duplication; affects the ring finger in most cases. • Stelling type II variants usually occur with syndactyly. Treatment • Types I and III: excision with soft tissue reconstruction. • Type II synpolydactyly may share tendons, nerves and vessels with adjacent fingers. ∘ The most suitable skeletal and tendinous elements are selected to create the best digit. Radial polydactyly • Refers to duplication of the thumb – preaxial polydactyly. • Isolated thumb polydactyly is usually unilateral and sporadic. • Syndromal association is documented but rare. ∘ Children should be screened for Fanconi’s anaemia. • Unlike ulnar polydactyly, it affects Caucasians more than African Americans. • Typically, there is a degree of hypoplasia of both duplicates. • Neurovascular anatomy is variable; most have only one vessel to each duplicate. Classification • Wassell’s classification, with prevalence of each type: ∘ Type I: bifid distal phalanx (2%) ∘ Type II: duplicated distal phalanx (15%) ∘ Type III: bifid proximal phalanx with duplicated distal phalanx (6%) ∘ Type IV: duplicated proximal and distal phalanx (43%) ∘ Type V: bifid metacarpal with duplicated proximal and distal phalanx (10%) ∘ Type VI: duplicated metacarpal, proximal and distal phalanx (4%) ∘ Type VII: triphalangeal thumb accompanied by a normal thumb (20%). Surgical correction • The goal is to create the best thumb possible using parts of each duplicate: ∘ A well-aligned thumb with stable joints, balanced motor functions and a cosmetic nailplate. • Surgery is usually done at 1 year, prior to development of thumb-index pinch. • In deciding which duplicate to retain, consider: ∘ Size – occasionally one is rudimentary. ∘ Deviation – at the point of duplication or at distal joints. ∘ Function – can differ between duplicates; functions may be shared. – Flexion in one but extension in the other. ∘ Passive mobility – both normal and abnormal. ∘ Radiological appearances – may reveal a triphalangeal thumb. The Upper Limb 325 • Surgical options: 1 Removing one duplicate and reconstructing the other. – For types III and IV, or types I and II with significant asymmetry. – The radial duplicate is usually proximal and smaller than the ulnar. – Radial collateral ligaments should be reconstructed. • Usually by taking a periosteal sleeve from the digit to be amputated. – Intrinsic muscles are reattached in a similar fashion. – Additional articular facets of the proximal joint surface are excised. • Improves angular deformity. – The reconstruction is protected with a transarticular K wire for 4 weeks. – Principles of treatment are similar for types V and VI. • More complex reconstruction of the intrinsics is required. • In addition, first webspace narrowing may need to be addressed. 2 Removing parts of both duplicates and combining the remaining tissue. – Symmetric types I and II are treated this way. – The Bilhaut-Cloquet procedure shares equal parts of each: • Remove adjacent inner halves of each duplicate. • The remaining outer segments are brought together and secured with sutures or K wire. – Problems include nail deformity, epiphysiodesis and joint stiffness. – Proposed modifications involve unequal sharing of parts: • The entire nail bed is taken from one of the duplicates. • Bone resection preserves the entire physis and joint surface from one of the duplicates. Triphalangeal thumb polydactyly • The duplicate has three rather than two phalanges. • Relatively common; usually an autosomal dominant trait. • The extra ‘middle’ phalanx may be: 1 Triangular (a delta phalanx) 2 Rectangular but short 3 Rectangular and normal length. • Treatment follows the principles above. • If the triphalangeal duplicate is retained, the extra interphalangeal joint (IPJ) must be addressed: ∘ Any delta phalanx is excised and soft tissues reconstructed. ∘ If the extra phalanx is rectangular – chondrodesis of the least mobile joint. Mirror hand • Rare condition – symmetrical duplication of the limb in the midline. ∘ Quoted incidence of 60 cases per 300 years. • A central digit with three fingers either side representing middle, ring and little. • Results in a hand with at least seven fingers but no thumb. 326 Chapter 5 • The forearm has two ulnae (no radius) that support a duplicated ulnar carpus. • The elbow is usually stiff and forearm rotation reduced. • The surgical anatomy is variable and complex. Treatment • Passive stretching and mobilisation of the elbow. • Fabrication of a first webspace. • Pollicisation and reducing the number of fingers. • It is a rarely performed operation, even for congenital hand specialists. Overgrowth Macrodactyly Enlargement of a digit noted at birth, or within the first years of life. True macrodactyly is enlargement of both the soft tissue and skeleton of a finger. Aetiology is unknown. It is distinct from conditions such as haemangiomas, vascular malformations and Ollier’s disease (multiple enchondromatosis) where overgrowth is due to a specific lesion. • Macrodactyly is usually unilateral; the index finger is most commonly affected. • Multiple digits can be involved; can also affect toes. • Enlargement often corresponds to the cutaneous distribution of specific nerves. ∘ ‘Nerve territory-oriented macrodactyly’ describes this relationship. • • • • Classification 1 Static macrodactyly: the enlarged finger grows in proportion to the rest of the hand. 2 Progressive macrodactyly: the enlarged finger grows out of proportion to the rest of the hand. • Flatt classifies macrodactyly according to the pathology: ∘ Type I: Lipofibromatosis – Epineural and perineural fibrosis with fatty infiltration of the nerve. ∘ Type II: Neurofibromatosis – Occurs in conjunction with plexiform neurofibromatosis. ∘ Type III: Digital hyperostosis Osteochondral periarticular nodules but no nerve enlargement. ∘ Type IV: Hemihypertrophy – Commonly known as Proteus syndrome. Surgical correction • Complicated by delayed healing due to relative vascular insufficiency (vessels are rarely enlarged). • Surgical options are usually inadequate: ∘ Soft tissue reduction, including digital nerve stripping ∘ Osteotomy ∘ Epiphysiodesis ∘ Amputation. The Upper Limb 327 Undergrowth Thumb hypoplasia • Most common site of clinically significant undergrowth. • Part of radial longitudinal deficiency – associated with the same syndromes. ∘ Children should be screened for Fanconi’s anaemia. Classification • Blauth’s classification has been modified into five groups: ∘ Type I – Minor generalised hypoplasia. ∘ Type II – Hypoplastic thenar muscles. – Adduction contracture of the first web. – Insufficiency of the UCL at the MCPJ. ∘ Type III – Features of type II plus abnormal extrinsic tendons. – Skeletal abnormalities further subclassify type III (Manske et al.): • A: stable carpometacarpal joint (CMCJ) • B: unstable CMCJ. ∘ Type IV – Small thumb attached to the hand by a soft tissue bridge. – Known as a floating thumb or ‘pouce flottant’. ∘ Type V – Total absence of the thumb. Surgical correction • Usually done at 1–2 years when thumb function is developing. • Type I: good function; do not require surgery. • Type IIIB, IV and V: ablation of any thumb elements and pollicisation. ∘ Pollicisation is described under ‘Radial deficiency’. • Type II and IIIA are reconstructed as follows: 1 First webspace release with, e.g. four-flap Z-plasty. – May require release of the first dorsal interosseous from the second metacarpal. 2 UCL reconstruction. – UCL deficiency may be primary or secondary to a pollex abductus. • This is an abnormal connection between FPL and EPL. – Any pollex abductus is released and the MCPJ stabilised: • Chondrodesis (joint fusion), or • Tendon graft to augment the vestigial UCL, or • UCL reconstruction incorporated into an FDS opponensplasty. 3 Opponensplasty to augment hypoplastic thenar muscle function. – Using the ring finger FDS is favoured by many due to its length, power and ability to reconstruct the UCL. – Others prefer the Huber transfer (ADM to APB). 328 Chapter 5 4 Extrinsic tendon reconstruction. – EIP can be transferred to EPL. – Reconstructing FPL may need pulley reconstruction in addition to tendon transfer. Brachydactyly • Brachydactyly (short finger) may occur in isolation, as part of a complex hand anomaly, or other syndrome. ∘ Often associated with syndactyly, clinodactyly and symphalangism. Treatment • Surgery is seldom required – function is relatively well preserved. ∘ Surgery frequently produces stiff fingers. • Brachymetacarpia may be corrected by distraction osteogenesis to restore normal cascade. Madelung’s deformity • Excessive radial and palmar angulation of the distal radius caused by growth disturbance of the palmar and ulnar portion of the distal radial physis. • An abnormal palmar ligament may tether the lunate to the radius (Vickers’ ligament). • Deformity becomes apparent in early adolescence; usually bilateral. • The distal ulna is prominent dorsally; ulnar deviation of the wrist is limited. • The forearm is usually short but function is minimally impaired. • More severe cases may be limited by pain. • Madelung’s may form part of Leri–Weill dyschondrosteosis, a genetic condition resulting in short stature. ∘ For this reason it is sometimes classified as a ‘generalised skeletal abnormality’. Treatment • No treatment is required for painless deformities. • Surgery may involve: 1 Resection of Vickers’ ligament and dome osteotomy to correct the radius. 2 Closing wedge osteotomy of the radius with ulnar shortening. 3 Opening wedge osteotomy of the radius. 4 Osteotomy of the radius and distal ulnar resection. 5 Osteotomy of the radius and a Sauvé–Kapandji procedure. – This fuses the distal radio-ulnar joint (DRUJ) and resects a segment of ulna to allow forearm rotation. Constriction ring syndrome • Constriction rings, or amniotic bands, form partial or complete circumferential constrictions around limbs or digits. • This can lead to: 1 Acrosyndactyly 2 Terminal absence or amputation 3 Localised swelling with oedema distal to the constrictions. • Occurs sporadically; affects one in 15,000 live births. The Upper Limb 329 • 50% of cases are associated with talipes equinovarus, cleft lip and palate, haemangioma, and cranial or cardiac defects. • Aetiology may be disruption of the amniotic membrane with release of amniotic bands that encircle limbs in utero. Classification • Patterson’s classification: 1 Simple constriction rings 2 Rings accompanied by distal deformity, with or without lymphoedema 3 Rings accompanied by distal fusion: acrosyndactyly 4 Intrauterine amputations. Surgical correction • Digital ischaemia at birth is rare. ∘ Requires surgical release, although the distal limb rarely survives. • Centres of expertise have released bands fetoscopically. • Nerve palsies can be difficult to treat because there may not be a distal nerve trunk. • Treatment of the ring itself is done for cosmesis and function. • Excision of the constriction band and soft tissue release with Z or W plasties is done for most cases. • Traditionally, no more than half the circumference was released at one sitting due to risk of distal ischaemia. ∘ However, complete circumferential release can be performed safely. • Principles of acrosyndactyly management are similar to syndactyly. • Intrauterine amputations, in contrast to other congenital causes of absent digits, have intact proximal bone, tendon and neurovascular structures. ∘ This makes toe transfer an attractive option for restoration of function. Hand trauma Assessment • Identify and treat all immediately life-threatening injuries prior to considering the hand injury. History • Hand dominance, occupation, hand-critical hobbies. • Mechanism of injury and forces involved. • Time of injury, particularly ischaemia time. • If machinery is involved: ∘ Configuration of the moving parts ∘ How much force it delivers ∘ What material is normally cut or deformed by the machine ∘ Are parts of the machine heated and to what temperature? • If an electrical saw is involved: thickness of the saw blade. 330 Chapter 5 • The direction a knife or shard of glass entered the skin. • Position of the hand at the time of injury. Examination 1 Is the injured hand or finger viable? 2 Vascular injury or compartment syndrome? 3 Tendon, nerve or bony injury? 4 True skin loss, or impending skin loss? • Plain X-rays assist with pre-operative assessment. • Fractures and dislocations present with swelling, deformity and loss of function. ∘ On palpation, there is tenderness, crepitus and abnormal motion. – Abnormal motion is also seen with periarticular ligament injury. • Tendons are initially assessed by inspecting the posture of the hand. • Passive flexion and extension of the wrist can demonstrate tendon integrity by the tenodesis effect. ∘ However, partial tendon division or isolated FDS division will appear normal. ∘ Intrinsic muscles can extend IPJs even when extrinsic extensors are divided. • Active motion of each tendon is then tested independently. • Composite motion produces the following grip types: 1 Power grip 2 Pinch grip – Pure (tip) pinch – Tripod pinch – Key (lateral) pinch. • Nerve injuries present with sensory loss, motor loss or both. • Sensation is grossly assessed by stroking within a nerve territory and simultaneously comparing with the uninjured hand. • Sweating is lost in the distribution of a divided peripheral nerve. ∘ Skin feels smooth and dry. ∘ The tactile adherence test assesses sweating by lightly dragging the smooth surface of a plastic pen along the skin. • Sensation is assessed more objectively by static and dynamic two-point discrimination (2PD): ∘ If a specific tool is unavailable, a paper clip can be folded into two points. ∘ The pressure applied should not result in blanching. ∘ Guideline values for normal 2PD are: – Distal phalanx pulp – 4 mm – Middle phalanx pulp – 5 mm – Proximal phalanx pulp – 6 mm – Distal palm – 7 mm – Mid-palm – 8 mm – Proximal palm – 9 mm – Dorsal hand – 15 mm – Volar forearm – 25 mm. The Upper Limb 331 • Paralysis of APB most reliably indicates median nerve injury. • Paralysis of FDM most reliably indicates ulnar nerve injury. ∘ Other intrinsic muscles may be cross-innervated. Position of safe immobilisation (POSI) • Immobilising the hand has the following advantages: ∘ Pain relief ∘ Reduction of post-traumatic inflammation and oedema ∘ Protection of soft tissue repairs ∘ Splinting of fractures. • The POSI, also called intrinsic-plus or Edinburgh position, is: 1 Wrist in 0∘ –30∘ of extension – Decreases MCPJ extension by the tenodesis effect. 2 MCPJs in 70∘ –90∘ of flexion – Places the collateral ligaments at their maximum length. 3 IPJs in full extension – Prevents volar plate shortening. 4 Thumb abducted and pronated – Prevents first webspace contracture. • Splintage is combined with elevation to reduce oedema. Tourniquets in hand surgery • Modern tourniquet units are pneumatic and microprocessor-controlled. Guidelines for safe use • There is little evidence in support of any guidelines. • Use the widest cuff possible – wider cuffs occlude at lower pressure. • Wrinkle-free padding under the cuff minimises risk of skin pinching. • Avoid aggressive exsanguination for infection or malignancy. • Suggested maximum inflation pressure for the upper limb is 250 mmHg, or 100 mmHg above systolic blood pressure. • Suggested maximum inflation time is 2 hours; the evidence ranges from 45 minutes to 4 hours. • Breaks of 20 minutes allow the venous pH of the limb to normalise between inflations. Complications of tourniquet use Local • Muscle injury ∘ Mechanical compression by the cuff ∘ Ischaemia beneath and distal to the cuff ∘ Reperfusion injury following tourniquet deflation. • Nerve injury ∘ Most occurs directly under the cuff. ∘ Disturbance of myelin and nodes of Ranvier due to mechanical pressure. 332 Chapter 5 ∘ ∘ Tourniquet-related nerve injury has a reported incidence of 0.1–8%. Most lesions recover spontaneously within 6 months. • Vascular injury ∘ Rare – thought to occur when atheromatous plaques rupture. • Skin injury ∘ Chemical burns – seepage of alcoholic skin preparations beneath the tourniquet. ∘ Pressure necrosis – inadequate padding or poor application of the tourniquet. • Tourniquet pain ∘ Dull aching pain that develops after 10–20 minutes. ∘ Can occur despite regional anaesthesia, possibly because C fibres are more resistant to local anaesthetic. Systemic • Cardiovascular effects ∘ Poorly tolerated in patients with little cardiac reserve. ∘ Limb exsanguination can increase circulating volume by 15%. – May precipitate cardiac failure. ∘ Tourniquet release decreases CVP and mean arterial pressure due to: – Shift of blood back into the limb. – Release of ischaemic metabolites causing myocardial depression. • Pulmonary effects ∘ Increased end-tidal CO2 following tourniquet release. ∘ Acute lung injury has been described after limb reperfusion. • Neurological effects ∘ Increased PaCO2 following deflation increases cerebral blood flow. ∘ Causes reflex decrease in systolic blood pressure, which can critically decrease cerebral perfusion pressure in a brain-injured patient. Replantation and revascularisation • Replantation is the reattachment of totally amputated parts. • Revascularisation is the repair of incomplete amputations. 1 Macroreplantation ∘ The amputated part contains muscle bulk and is therefore less resistant to ischaemia. ∘ Muscle necroses after 6 hours of warm ischaemia or 12 hours of cold ischaemia. 2 Microreplantation ∘ The amputated parts are usually digits that are more resistant to ischaemia. ∘ Digits tolerate at least 12 hours of warm ischaemia or 24 hours of cold ischaemia. • The expectations of the patient must be addressed: ∘ Many choose terminalisation rather than replantation for a shorter recovery time. Relative indications • Thumb • Multiple digits • Amputation through the palm • Almost any part in a child • Wrist, forearm, elbow and above elbow The Upper Limb 333 • Single digit distal to the FDS insertion • Patients who ‘must’ have a 10-digit hand, e.g. musicians. Relative contraindications • Severely crushed or mangled parts • Avulsion injuries with structures dangling from the part associated with: ∘ The ‘red streak sign’ – bruising over the neurovascular pedicle. ∘ The ‘ribbon sign’ – a corkscrew appearance to the vessels. • Amputations at multiple levels • Extreme contamination • Previous injury of the amputated part • Other serious injuries or diseases • Severe atherosclerosis • Prolonged ischaemia time • Mental instability • Single digit proximal to the FDS insertion. Ring avulsions • Classified by Urbaniak et al. ∘ Class I: Circulation adequate. ∘ Class II: Circulation inadequate. Microvascular reconstruction will restore circulation and function. ∘ Class III: Complete degloving or complete amputation. • Class III amputations, particularly proximal to the FDS insertion, have poor prognosis and are best terminalised. • Others have subdivided class II injuries: ∘ IIA: Only digital arteries require repair. ∘ IIB: Arteries, bone, tendon or nerves are involved. ∘ IIC: Only veins are involved. • Replantation may be attempted distal to the FDS insertion if the PIPJ and proximal phalanx are intact. Transportation of the amputated parts • Aim to keep the part cool, prevent freezing and avoid maceration. • This can be achieved by: ∘ Wrapping the part in moist gauze and placing it in a sealed container or bag. ∘ This is then placed in another container or bag containing ice and water. Surgical treatment • Two surgical teams greatly shorten the operative time. Team 1 • Osteosynthesis is planned based on X-rays of the hand and amputated part. • The part is debrided and neurovascular structures tagged in theatre. ∘ Longitudinal midaxial incisions give good exposure. • Bone shortening may allow primary repair of neurovascular structures. 334 Chapter 5 • The distal half of the bony fixation can be inserted into the amputated part in advance. • Common methods of fixation: ∘ K wires ∘ Interosseous wires ∘ Miniplates and screws. Team 2 • Debride the stump and tag neurovascular structures. • Shorten and fix the bone. • Repair the extensor and flexor tendons. • Anastomose the arteries, coapt the nerves, then anastomose the veins. • Skin cover. • Interposition vein grafts or vessel transposition from an adjacent finger may be required. ∘ Grafts from the volar wrist match the calibre of digital arteries. ∘ Grafts can be placed extra-anatomically to the radial artery at the wrist. • If suitable veins are not available, venous drainage may be achieved by: 1 Repairing any volar veins. 2 Anastomosing a digital artery (which has backflow) to a vein, creating an arteriovenous fistula. 3 Removing the nail plate and scraping the sterile matrix to encourage bleeding with heparin-soaked gauze. 4 Stab incisions of the periungual area and topical heparin. 5 Medical leeches. Special considerations in macroreplantation • The priority is establishing arterial inflow to minimise muscle necrosis. ∘ Achieved by a temporary vascular shunt, such as a Sundt, Pruitt-Inahara or Javid shunt. • Considerable bone shortening is required if amputated through muscle bellies. ∘ Shortening also makes primary vessel and nerve repair easier. • Fixation of bone is then done, prior to definitive arterial repair. • Venous blood is drained from the amputated part for some time to flush accumulated toxic metabolites. ∘ Blood transfusion is usually required. • Fasciotomies are always indicated. • Assess for further muscle necrosis within 48–72 hours under general anaesthesia. Fingertip injuries Nail bed injury • Usually caused by doors in children and DIY tools in adults. • All require X-ray because 50% have an underlying fracture. Classification • Subungual haematoma • Simple lacerations The Upper Limb 335 • Stellate lacerations • Severe crush • Avulsion. Treatment • Haematoma with intact nail edges is treated by trephination of the nail. • Disrupted nailplates are removed to allow assessment of the nail bed. • Lacerations are approximated with fine dissolving sutures or skin glue. • Nail bed avulsions can be replaced as grafts. • Central defects can be repaired directly after paronychial releasing incisions. • Split thickness nail bed graft from an adjacent finger or toe can be used for defects >30% of the width. • Associated distal phalanx fractures are normally reduced by approximation of the nail bed, and splinted by application of the nailplate. • If the fracture is unstable, K wires may be used. Fingertip amputation • Optimal management is controversial. • Reasonable attempts should be made to preserve the length of the thumb. Classification • Many systems are available, notably proposed by Tamai, Ishikawa and Allen. • Allen’s classification: ∘ Type I: pulp only. ∘ Type II: pulp and nail bed. ∘ Type III: distal phalanx fracture with associated pulp and nail loss. ∘ Type IV: lunula, distal phalanx, pulp and nail loss. Treatment • The amputated part can be replaced as a composite graft. ∘ Most successful in children <3 years old when replaced within 5 hours. • If replantation or composite grafting is not possible or not indicated: Healing by secondary intention • Considered by many to be the best option when bone is not exposed. ∘ Exposed bone can be shortened to allow healing to occur. Skin grafting • Studies show superior results are obtained by allowing the wound to heal. Local and regional flaps • Prior to flap surgery, the surgeon should be satisfied that the outcome will be superior to bone shortening and healing by secondary intention. • Rates of cold intolerance and altered sensation are similar with both treatments. 336 Chapter 5 • Options include: ∘ Atasoy-Kleinert volar V-Y ∘ Kutler lateral V-Y ∘ Segmüller lateral V-Y ∘ Homodigital island ∘ Venkataswami advancement ∘ Evans step advancement ∘ Cross-finger ∘ Thenar. • Tension on the nail bed is avoided during inset to avoid a hook nail. • Many advocate resecting the nail bed if <25% remains ∘ Nail spikes and cysts can result if the nail bed is not completely excised. Thumb reconstruction • Thumb reconstruction should address: 1 Sensation – To allow interaction with the environment – Protection – Freedom from pain. 2 Opposition – Length – Stability – Strength – Mobility. • Loss of the distal phalanx may not lead to functional problems. • Amputation proximal to the shaft of the proximal phalanx is inadequate for pinch and power grip. Classification • Lister has rationalised thumb defects: 1 Acceptable length with poor soft tissue cover. 2 Subtotal amputation with questionable remaining length. 3 Total amputation with preserved CMCJ. 4 Total amputation with loss of the CMCJ. Treatment • Treatment is dictated by Lister’s classification: Acceptable length with poor soft tissue cover • Healing by secondary intention. • Revision amputation. • V-Y advancement flaps, as described for fingertip injuries. • Moberg volar advancement flap. • Innervated cross-finger flap. • First dorsal metacarpal artery (FDMA) flap (Foucher, 1979). • Littler heterodigital island flap. The Upper Limb 337 Subtotal amputation with questionable remaining length • Deepening the first webspace to relatively lengthen the stump. Total amputation with preserved CMCJ • Free toe transfer is ideal. • Alternatively: ∘ Metacarpal distraction lengthening. ∘ Osteoplastic reconstruction (bone graft covered with soft tissue flap). ∘ Pollicisation of an injured or partially amputated digit. Total amputation with loss of CMCJ • Pollicisation. Toe-to-hand transplantation • The aim is to provide a thumb and two fingers for tripod pinch. Anatomy • Most transfers are based on the lateral digital artery to the great toe, or medial digital artery to the second toe. • Toe digital arteries arise from two systems: 1 Dorsal arterial system, from dorsalis pedis. 2 Plantar arterial system, from plantar metatarsal arteries. • Determining which system is dominant is key when harvesting a toe. ∘ First dorsal metatarsal artery is dominant in 70%. ∘ First plantar metatarsal artery is dominant in 20%. ∘ In 10%, both systems are of equal calibre. • Most are harvested with the superficial dorsal venous system. • Plantar sensation is supplied by plantar digital nerves. Variants of toe transfer Great toe transfer • Used to reconstruct a thumb. • The donor site may be unacceptable to some patients. Wraparound technique • Uses the great toenail, skin envelope and bone graft. • Gives a smaller thumb than conventional great toe transfer. • Does not restore joint mobility. • Not used in children due to the lack of capacity for growth. Trimmed great toe transfer • Combines the advantages of toe transfer and wraparound technique. • Harvested like a conventional great toe transfer. • Longitudinal osteotomy removes a strip of bone from the side of the phalanges. • Soft tissue is excised from the medial side to match the intact thumb. 338 Chapter 5 Second toe transfer • Used following finger amputations. • Can reconstruct a thumb for those who prefer the donor site to that of the great toe. • Disadvantages: tendency to claw, bulky pulp. Second toe wraparound transfer • For distal soft tissue loss of the fingers. • The distal phalanx is included to prevent pulp instability and nail deformity. Third toe transfer • Rarely used; indicated if a second toe is not available. Combined toe transfer • Useful if two adjacent digits are required. • Combinations of second-third or third-fourth toes can be transferred. • Provides a webspace, and both toes are supplied by a shared pedicle. Vascularised joint transfer • Indicated for a destroyed PIPJ or MCPJ. • Limited range of motion, but is stable, durable and shows capacity for growth. • Usually harvested from the second toe, based on articular branches from the medial digital artery. Neurosensory free flaps • Useful for large pulp defects that cannot be reconstructed with local flaps. • Free pulp flaps from the great toe provide potentially sensate glabrous skin from a donor site that is closed primarily. • First webspace flaps are thin, potentially sensate islands of glabrous skin. Donor site • Sequelae of toe harvest should be discussed in detail with patients. • Photographs of feet following toe harvest should be shown. • The donor site should be closed primarily with minimal tension. • Most patients do not have problems walking. ∘ Some experience fatigue when playing ball sports. Fractures and dislocations Collected words of wisdom • There is a wide range of acceptable treatment. • Little evidence supports superiority of one method over another. • Treat fractures using methods that work for you. ∘ Some eminent hand surgeons treat almost all fractures non-operatively. ∘ Others treat almost all fractures operatively, with similar results. • Surgery causes bleeding, swelling, scarring, and implants can become infected. ∘ Operative treatment can therefore result in worse outcomes than no treatment. The Upper Limb 339 • More aggressive surgery generally attracts more spectacular complications. • First do no harm – do not operate unless you can provide a superior outcome to nonoperative management. • Oedema causes stiffness – elevate the fractured limb above heart level. Principles of fracture management Assessment • Identify and treat immediately life-threatening injuries prior to considering the hand fracture. • Assessment should answer these specific fracture-related questions: 1 Is there a wound communicating with the fracture? 2 Is there evidence of neurovascular injury? 3 Is there evidence of associated soft tissue injury, e.g. tendon or ligament? Investigation • Most hand fractures are adequately imaged with plain X-ray. • Complex intra-articular fractures may require a CT scan. • Ultrasound and MRI assess soft tissue detail. Treatment • The three fundamental principles of fracture treatment are: 1 Reduction • By closed manipulation • By mechanical traction • By open surgery. – Minimal displacement or displacement of no functional consequence do not need reduction. – Translation is generally better tolerated than angulation or rotation. 2 Immobilisation • To prevent displacement of the fragments. • To prevent movement that might interfere with bone union. • To relieve pain. – Immobilisation can be achieved by: • External splint, e.g. plaster of Paris or Zimmer splint • Continuous traction • External fixation • Internal fixation. – Indications for fixation include: • Irreducible fractures, particularly if malrotated • Intra-articular fractures • Subcapital fractures of the phalanges • Open fractures • Segmental bone loss • Polytrauma with hand fractures 340 Chapter 5 • Multiple hand or wrist fractures • Fractures with soft tissue injury (vessel, tendon, nerve, skin). – Methods of internal fixation include: • K wires • Interosseous wires • Intramedullary devices • Screws • Plates. 3 Rehabilitation – Rehabilitation is required for all fractures. – Begin as soon as possible, with supervision from a hand therapist. – Aims of rehabilitation: 1 Preserve hand function during fracture union. 2 Return hand function to normal once the fracture has united. – It is unusual to immobilise a hand fracture for more than 3–4 weeks. – Prolonged immobilisation leads to stiffness. Complications of fractures Early • Neurovascular and other soft tissue injury. • Compartment syndrome. Late • Delayed union • Non-union • Malunion • Joint stiffness and contractures • Avascular necrosis • Complex regional pain syndrome • Osteomyelitis • Growth disturbance or deformity • Osteoarthritis (OA). Open surgical approaches to hand fractures • General aims: ∘ Provide adequate exposure ∘ Preserve the skin’s blood supply ∘ Be extendable if necessary ∘ Avoid scar contracture. Dorsal approach • Often used for metacarpals and phalanges. • Over the DIPJ they can be shaped like an H, Y or L. The Upper Limb 341 • Dorsal veins and sensory nerves are preserved if possible. • The extensor tendon can be retracted over the metacarpal. ∘ Juncturae tendinum may need to be divided, but should be repaired. • Over the proximal phalanx the central slip is freed on one side and retracted. ∘ Alternatively, the central slip is split longitudinally. • The Chamay approach is a V-shaped incision through the extensor, allowing the central slip to be reflected distally. ∘ Gives excellent exposure of the head of the proximal phalanx. ∘ Requires skill to repair the central slip to avoid extensor lag and boutonnière. Lateral approach • Midaxial incision connects the centres of rotation of the IPJs. ∘ Surface markings are the dorsal extremes of the IPJ flexion creases. ∘ The digital NVB is volar to this incision. • Midlateral incision is halfway between the dorsal and volar surfaces. ∘ It is slightly volar to the midaxial line. • The midaxial incision is generally preferred because it is ‘mechanically neutral’. Volar approach • Few closed fractures are approached from the volar aspect. • Those that are include: ∘ Volar plate avulsion fracture of the middle phalanx base. ∘ MCPJ collateral ligament avulsion fracture of the base of the proximal phalanx. – The collateral ligament travels from the metacarpal to the volar base of the proximal phalanx. Metacarpal fractures • Rotational alignment is confirmed by asking the patient to make a fist. ∘ Fingers should all point to the scaphoid tubercle. • If the fracture is stable, it is held for 3–4 weeks until union takes place. • Methods of non-operative fixation include: ∘ Buddy strapping to an adjacent non-injured finger ∘ Bedford gaiter ∘ Plaster of Paris, aiming for 3-point fixation, e.g. ulnar gutter, Barton short hand cast, clam-digger cast. • Operative treatment is indicated for open fractures. ∘ Some surgeons also elect to internally fix closed fractures. • Fixation can be achieved by: ∘ K wires: transverse, longitudinal, ‘bouquet’ wiring. ∘ Lag screws ∘ Plates – newer low profile implants rarely require removal ∘ Interosseous wires ∘ External fixation. 342 Chapter 5 Fifth metacarpal neck fractures • So-called boxer’s fracture; often over-treated. • Well tolerated due to mobility of the CMCJs. • Rarely requires treatment unless rotated or angulated >70∘ . • Usually impacted and stable if left unreduced. • Patients are told to mobilise their fingers immediately as pain allows. • A Bedford gaiter or buddy strapping prevents significant extensor lag. • No follow-up is required. Phalangeal fractures • Rotational malalignment must be corrected. Distal phalanx • Shaft fractures usually splinted; can be K wired if grossly unstable. • Bony mallet injuries: splint for 6 weeks. ∘ Others advocate intervention if >30% of the articular surface is involved, but this is arbitrary. ∘ Operative fixation is indicated if the DIPJ is subluxed in a splint. Phalangeal shaft • Most can be treated conservatively; some elect to treat them operatively. • Fixation should avoid the IPJs so they can be mobilised. • K wires are popular – phalanges are easily accessed percutaneously. Intra-articular fractures • Aim of treatment is to restore joint congruity and subsequently: 1 Prevent deformity 2 Prevent OA 3 Restore early movement. • Should be fixed with absolute stability if possible. • Some fractures require detailed assessment with pre-operative CT. • Unicondylar fractures of the phalanges are inherently unstable. ∘ They require anatomical reduction. ∘ Management is rarely successful with external splintage. ∘ Percutaneous lag screws or K wires may be possible. – Otherwise open reduction is required. • Pilon fractures are comminuted intra-articular fractures. ∘ Common at the base of the middle phalanx. ∘ Result from axial loading – the head of the proximal phalanx is driven into the base of the middle phalanx. – Pilon is the French word for pestle (a heavy tool with a rounded end) ∘ The articular surface may be splayed. ∘ Outcome is unpredictable; stiffness is expected. The Upper Limb 343 ∘ For this reason, some favour dynamic external fixators over open reduction and internal fixation (ORIF): – Examples: Hynes–Giddins device (K wires only) and Suzuki frame (K wires and rubber bands). • ORIF usually requires bone graft to support the reduced articular fragments. • No method can repair the articular surface to its pre-injury state. Dislocations and subluxations DIPJ • Dislocations or subluxations are rare. • May be associated with avulsions of FDP or extensor tendon. • Integrity of the collateral ligaments is assessed after ring block. • Most (without tendon avulsion) are splinted for two weeks, then mobilised. PIPJ • Often missed or poorly treated; a great source of litigation. • Eaton classifies volar plate injuries of the PIPJ as follows: ∘ Type I (hyperextension) – Avulsion of the volar plate without fracture; collateral ligaments split. ∘ Type II (dorsal dislocation) – Complete dorsal dislocation; volar plate avulsion without fracture. ∘ Type III (fracture subluxation) – Fracture subluxation with a palmar fragment of variable size. • Palmar fragments <40% of the articular surface should leave enough collateral ligament attached to the middle phalanx to provide joint stability when reduced. • Larger palmar fragments suggest the joint may re-sublux following reduction. ∘ The ‘dorsal V sign’ on lateral X-ray indicates a subluxed joint. • Treatment: reduction and early mobilisation in an extension block splint. • Other options include transarticular K wire, ORIF of the palmar fragment or dynamic external fixator, e.g. Suzuki frame. MCPJ • Rare and easily missed. • Closed reduction may be impossible: ∘ The volar plate can flip into the joint. ∘ FDP, FDS and lumbricals form a ‘noose’ around the metacarpal neck. • Open reduction requires particular care not to injure the digital nerves. CMCJ • Uncommon in the radial four rays; indicative of high energy trauma. • Fifth CMCJ dorsal subluxation is relatively common. ∘ Results from axial force on the fifth metacarpal. ∘ Fracture of the metacarpal base is nicknamed a ‘reversed Bennett’s fracture’. ∘ There may also be a dorsal avulsion from the hamate. 344 Chapter 5 • Treatment options include: ∘ Closed reduction and splint ∘ Closed reduction and K wire into an adjacent metacarpal or carpus ∘ ORIF. • Inadequate or lost reduction leads to weak grip. Thumb fractures • More forgiving due to the greater range of motion in thumb joints. • Specific thumb fractures include: Bennett’s fracture–subluxation • Fracture–subluxation of the first carpometacarpal joint. ∘ Does not refer to all fractures in the region of the first metacarpal base. • Mechanism of injury is axial loading of the flexed CMCJ. ∘ The palmar oblique (‘beak’) ligament holds the fragment in the anatomical position. ∘ The remainder of the metacarpal is adducted and supinated by adductor pollicis. – Also pulled proximally by APL. • The fracture–subluxation is reduced by a combination of: 1 Longitudinal traction 2 Pronation of the metacarpal 3 Pressure at the base of the metacarpal. • The reduction can be held by applying a moulded below-elbow cast. • Persistent instability can be held with percutaneous K wires: 1 Transfixion of the metacarpal base to the trapezium. 2 Transfixion of the first metacarpal base to the second metacarpal. 3 Combination of both. • ORIF is indicated for irreducible fractures. ∘ Not usually feasible if the fragment is <20% of the articular surface. Rolando fracture • Three-part intra-articular fracture of the base of the first metacarpal. ∘ Mistakenly used to describe all comminuted fractures of the first metacarpal base. • Non-operative treatment is unlikely to reduce the articular surface. • ORIF with a T-plate is usually done through a dorsal or radiopalmar approach. • More comminuted ‘Rolando’ fractures are difficult to ORIF. ∘ External fixation can maintain a reasonable reduction and prevents metacarpal collapse. • Rolando fractures are often more comminuted than shown on X-ray. ∘ Some therefore routinely assess these injuries with CT scan. MCPJ UCL avulsion • Frequently missed, leading to instability and weakness of pinch. • Commonly seen in skiers that fall onto their thumbs (especially while holding a ski pole). ∘ Colloquially known as ‘skier’s thumb’. – ‘Gamekeeper’s thumb’ refers to chronic attenuation of the UCL. The Upper Limb 345 • The avulsed ligament can displace dorsal to the adductor aponeurosis. ∘ Known as a Stener lesion. ∘ The interposed adductor aponeurosis eliminates any chance of spontaneous bony or ligamentous healing. • Incomplete injuries are managed conservatively in a cast for 4–6 weeks. • Complete injuries increase the likelihood of a Stener lesion, requiring surgical repair. ∘ Stress testing of the UCL is done with the MCPJ in 30∘ of flexion. ∘ Comparing with the uninjured side, >15∘ difference or a soft end-point suggests complete rupture. • The UCL can be reattached using a Mitek bone anchor. ∘ Repair is protected for 4 weeks; activity is gradually increased thereafter. Paediatric hand fractures • The vast majority can be managed non-operatively. • The presence of a physis means that deformity can be remodelled with growth. • Greatest remodelling potential is seen with the following: ∘ When angulation occurs in the plane of adjacent joint motion. ∘ When the fracture is in close proximity to the physis. ∘ When the fracture is in a young child with many years of remaining growth. • Rotational and angular deformity has little remodelling potential. • The physis should be respected during surgery. • Salter–Harris classification of physeal fractures: ∘ Type I – fracture through the physis (6%) ∘ Type II – fracture through the physis and metaphysis (75%) ∘ Type III – fracture through the physis and epiphysis (8%) ∘ Type IV – fracture through the epiphysis, physis and metaphysis (10%) ∘ Type V – fracture compressing the physis (1%) • Types III, IV and V are associated with physeal growth arrest. • Specific paediatric hand fractures include: Seymour fracture • Looks like a mallet ‘drop finger’, but is transepiphyseal rather than transarticular. • Usually open with nail bed involvement. • The fracture is distracted by the extensor tendon on the proximal fragment and FDP on the distal fragment. • Requires debridement, reduction, nail bed repair and replacement of the nailplate as a splint. ∘ An axial transarticular K wire can be passed if unstable. Phalangeal neck fractures • Typically occur following trapping a finger in a door. • The distal fragment is usually angulated dorsally into extension ∘ Results in incomplete flexion at the PIPJ. • Minimally displaced fractures can be splinted, but require weekly X-rays. • Displaced fractures require closed reduction and K wire. 346 Chapter 5 Tendon injury Flexor tendons • Verdan described five zones of flexor tendon injury: ∘ Zone 1: distal to FDS insertion. ∘ Zone 2: between proximal flexor sheath and FDS insertion. ∘ Zone 3: between distal flexor retinaculum and proximal flexor sheath. ∘ Zone 4: under the flexor retinaculum. ∘ Zone 5: proximal to the flexor retinaculum. – Zone 2 repair is complicated by having two tendons in a tight sheath. • Thumb zones: ∘ Zone T1: distal to IPJ. ∘ Zone T2: from A1 pulley to IPJ. ∘ Zone T3: in the thenar eminence. ∘ Zones T4 and T5 are the same as for the fingers. • FDP can be avulsed from its bony attachment. ∘ Caused by a hyperextension force on an actively flexed DIPJ. ∘ Known as ‘rugger jersey finger’ – a tackler grabs the opponent’s rugby shirt. ∘ The ring finger is most commonly injured because it is the ‘longest’ flexed finger. • Leddy and Packer classify FDP avulsions: ∘ Type I: tendon retracts into the palm; rupture of both vincula. ∘ Type II: tendon retracts to the PIPJ; long vinculum intact. ∘ Type III: a large bony fragment avulsed with the tendon prevents retraction beyond the A4 pulley. Flexor tendon repair Skin incision • An extensile exposure is planned. • Popular approaches include the Brunner and midlateral. The flexor tendon sheath • A synovial-lined fibro-osseous tunnel in the fingers and thumb. • Runs between the metacarpal neck and DIPJ. • Synovial portion contributes to tendon glide and nutrition. • Retinacular portion contributes mechanical efficiency. • Retinacular part consists of five annular (A) and three cruciform (C) pulleys: ∘ A1, A3 and A5 originate from the volar plates of MCPJ, PIPJ and DIPJ, respectively. ∘ A2 and A4 originate from proximal and middle phalanx, respectively. ∘ Cruciform pulleys are collapsible; they ‘concertina’ to allow flexion. • Pulleys are ordered from proximal to distal as follows: ∘ A1 – A2 – C1 – A3 – C2 – A4 – C3 – A5. • The thumb has two annular pulleys overlying the MCPJ (A1) and IPJ (A2). • An oblique pulley runs between the two: from ulnar on the proximal phalanx to radial on the distal phalanx. The Upper Limb 347 • The sheath usually needs to be opened for access to the tendon ends. ∘ As much sheath as possible should be preserved to maintain function. ∘ Function is usually adequate if either A2 or A4 is preserved. • Closure of the sheath is controversial, particularly if it limits glide. ∘ An alternative to venting zone II pulleys is excising a slip of FDS. The tendon repair • Results are better when repair is done within the first few days of injury. • The following principles apply to most techniques: ∘ Handle tendon ends as little as possible. ∘ Repair should be strong enough to allow early mobilisation. ∘ Strength of repair is dependent on: – Gauge of suture – 3/0 is stronger than 4/0. – Number of strands crossing the repair – four are stronger than two. – Configuration of the peripheral suture. – Tendon-suture interaction – grasping sutures pull through easily; locking sutures ‘lock’ a bundle of tendon fibres, minimising suture pullout. ∘ Excessive suture bulk can increase resistance to tendon glide. ∘ No gapping of the tendon ends on mobilisation. – A 2 mm gap increases gliding resistance significantly. – A 3 mm gap is unlikely to pass under the A2 pulley without rupture. ∘ Avoid shortening FDP >1 cm – quadriga may ensue. – The quadriga phenomenon was described by Verdan. – Occurs when FDP excursion in an unaffected finger is reduced as a result of decreased FDP excursion in another finger due to stiffness, injury or adhesion. • Decreases global grip strength because all FDPs share a common muscle belly. • Most repairs use core and peripheral sutures. • No evidence that using ‘cutting’ needles gives a higher rupture rate. • Examples of core sutures include: ∘ 2-strand repair – Kessler, with two knots on the outside of the tendon. – Modified Kessler, with a single knot within the repair site. ∘ 4-strand repair – Cruciate – Adelaide (modified Savage) ∘ 6-strand repair – Savage. • Peripheral sutures do the following: ∘ Align tendon ends prior to core suture (back wall first). ∘ Tidy up tendon ends following core suture. ∘ Contribute significant strength to the repair. • Examples of peripheral sutures include: ∘ Strickland simple continuous suture 348 ∘ ∘ Chapter 5 Silfverskiöld cross-stitch Halsted continuous horizontal mattress. Partial injury • Lacerations up to and beyond 75% of the cross sectional tendon area maintain adequate strength at physiological loads. • Partial lacerations may cause triggering – the triggering part should be trimmed. • Placing epitendinous sutures into partial lacerations doubles the gliding resistance. ∘ This is unnecessary; may require sheath incisions for access. Rehabilitation following repair of flexor tendons • Tendons were historically immobilised in the belief that adhesions were necessary for healing. • Discovery of intrinsic healing allowed early mobilisation to improve glide. • Most regimes require a dorsal blocking splint to protect the repair. • The splint is maintained for up to 6 weeks. • Heavy use is avoided for 12 weeks total. • Common regimes are variations on the following: Immobilisation • Mainly for children or adults unsuitable for early mobilisation. Early passive mobilisation • No active movement is permitted. Early active extension with passive flexion • Advocated by Kleinert et al. • Finger flexion is maintained by rubber-band traction. • Active extension is done against the recoil of the bands. • Passive flexion occurs by elastic recoil of the bands. • Critics state that PIPJ extension lag is a problem due to prolonged PIPJ flexion. • It is also regarded as a poor mobiliser of the DIPJ. Early active mobilisation • Strength of repair is increased by early active flexion. • The ‘Belfast’ regime is widely used in the United Kingdom in modified forms. • Active mobilisation is started 48 hours after the operation. • Exercises are repeated two-hourly throughout the day: ∘ Two passive movements, then two active movements of the finger(s). • The aim is full passive flexion in the splint within the first week. • Range of active motion is gradually increased. Outcomes • Rupture and adhesion affect 5% of flexor tendon repairs. The Upper Limb 349 • No consensus on ideal outcome measures. ∘ Most measure range of motion. ∘ The commonly used systems have never been validated. • The total active motion (TAM) evaluation system is proposed by the ASSH: ∘ TAM = total active flexion − total extension deficit (for MCPJ, PIPJ and DIPJ) – This flatters suboptimal zone II repairs because the MCPJ is unaffected. • Strickland’s system addresses this shortcoming by assessing IPJs only: Active flexion of PIPJ and DIPJ − Extension deficit of PIPJ and DIPJ × 100% 175∘ • Functional assessments are rarely quoted in the literature, but include: ∘ Grip and pinch strength, Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, Michigan hand questionnaire. ∘ Global assessments may not be sensitive enough for isolated flexor tendon injuries. Extensor tendons • Divided into eight zones: ∘ Zone 1: over DIPJ ∘ Zone 2: between PIPJ and DIPJ ∘ Zone 3: over PIPJ ∘ Zone 4: between MCPJ and PIPJ ∘ Zone 5: over MCPJ ∘ Zone 6: between MCPJ and extensor retinaculum ∘ Zone 7: under the extensor retinaculum ∘ Zone 8: between extensor retinaculum and musculotendinous junction. • In the thumb: ∘ Zone T1: over IPJ ∘ Zone T2: over proximal phalanx ∘ Zone T3: over MCPJ ∘ Zone T4: between MCPJ and extensor retinaculum ∘ Zone T5: under the extensor retinaculum. Extensor tendon repair • The morphology of extensor tendons changes from proximal to distal: ∘ Forearm and wrist: tendons are thick; capable of holding core sutures. ∘ Finger: tendons become broad and thin; do not take core sutures well. • Suggested techniques of repair: ∘ Zone 1: running suture that may incorporate the skin (dermotenodesis). ∘ Zone 2: running suture reinforced with Silfverskiöld cross-stitch. ∘ Zones 3–5: modified Kessler core reinforced with Silfverskiöld. ∘ Zones 6–8: As for zones 3–5; the cross-stitch can be circumferential. Rehabilitation following repair of extensor tendons • Zone 1: mallet injury. Splint with slight hyperextension of the DIPJ for 6–8 weeks. 350 Chapter 5 • Zone 2: similar to zone 1. • Zone 3: static PIPJ immobilisation in extension for 6 weeks. ∘ DIPJ is free to flex to ensure lateral bands do not shorten, leading to boutonnière. • Zone 4: distal injuries follow zone 3; proximal injuries follow zone 5. • Zones 5–7: the ‘Norwich’ regime is widely used in the United Kingdom. ∘ Volar splint – wrist 45∘ extension, MCPJs flexed >50∘ , IPJs extended. ∘ Controlled active mobilisation begins on day 1. ∘ Exercises are repeated four times each, four times a day, for the first 4 weeks: 1 Combined IPJ and MCPJ extension. 2 MCPJ extension with IPJ flexion (hook grip). ∘ After 4 weeks, the splint is worn at night only; MCPJ flexion is commenced. ∘ Full power grip should be possible by week 6. Flexor tendon reconstruction • A salvage procedure following: ∘ Failed primary tendon repair ∘ Crush injury ∘ Fractures ∘ Infections. • Appropriate patient selection is vital: ∘ They must agree to rigorous hand therapy and multiple operations. ∘ They should be prepared for recurrence of the deficit. • Timing of surgery is critical; usually after a period of hand therapy: ∘ Previous scars should be soft and supple. ∘ Joints should be mobile with passive range of motion > active range of motion. Management options 1 Do nothing 2 Tenolysis 3 Tendon transfer 4 Primary tendon graft ∘ Scar or granulation within the sheath, or sheath incompetence, requires two-stage reconstruction. 5 Two-stage tendon graft ∘ A passive silicone tendon rod (Hunter rod) is placed in the flexor sheath during the first stage. ∘ Pulleys and skin/joint contractures are reconstructed at the same time. ∘ Second stage 3–6 months later, after passive mobilisation exercises. – Tendon graft is placed into the pseudosheath formed around the rod. ∘ Common tendon graft donors: – Palmaris longus – Plantaris – Long toe extensors The Upper Limb 351 – Long toe flexors – EIP, EDM or FDS from the injured finger. Methods of securing tendon grafts • The ends of the graft are planned to lie outside the sheath. • Distally, they are usually secured to the base of distal phalanx: ∘ Suture or weave through the FDP stump. ∘ Where there is no FDP stump: – Bone anchor, e.g. Mitek. – Suture ends passed through or around distal phalanx, tied over the nail. – Graft passed through a transverse drill hole in distal phalanx. • Proximally, the most common technique is the Pulvertaft weave: ∘ Tendons are weaved together using a purpose-made instrument. ∘ The weave is tensioned to recreate the natural cascade of the fingers. ∘ Appropriate tension is confirmed by tenodesis across the wrist. Pulley reconstruction • Indicated when the pulley mechanism is insufficient to prevent bowstringing that limits active joint flexion. • Restoration of both A2 and A4 pulleys is attempted as a minimum. • Materials used for reconstruction include: ∘ Free tendon graft. ∘ Segment of wrist extensor retinaculum. ∘ Fascia lata. ∘ Slip of FDS. ∘ Artificial sources, including Dacron, silicone, PTFE. • Pulleys are fashioned in one of the following ways: ∘ Wrapping around proximal and middle phalanges in a double loop. ∘ Weaving through the remnants of the pulleys in a zigzag fashion. ∘ Suturing into holes drilled into the phalanx. ∘ Bone anchors. Alternatives to tendon reconstruction • Arthrodesis • Amputation. Hand infections • The most common pathogen is Staphylococcus aureus. Bite wounds • Majority are caused by: ∘ Dogs (60–90%) 352 Chapter 5 ∘ ∘ Cats (5–20%) Humans (4–23%). • Bites cause purulent wounds, deep abscesses, cellulitis and lymphangitis. Human • Human bites are either: ∘ Occlusal injuries, inflicted by actual biting, or ∘ Clenched fist injuries, when a fist hits someone’s teeth. • Clenched fist injuries (‘fight bites’) are particularly prone to infection. • Teeth inoculate bacteria into joints, causing septic arthritis. • Human saliva contains a mixture of aerobic and anaerobic bacteria: • Aerobic: ∘ S. aureus ∘ Staphylococcus epidermidis ∘ Streptococci • Anaerobic: ∘ Bacteroides ∘ Enterobacter ∘ Klebsiella ∘ Pseudomonas. • Eikenella corrodens is a facultative anaerobe. • There is a small risk of infection from blood-borne viruses, e.g. hepatitis B. ∘ Risk is at least 20 times less than from a needlestick injury. Management of clenched fist injuries • Innoculation of bacteria can affect: ∘ Dorsal subcutaneous space ∘ Subtendinous space ∘ Joint space ∘ Bone. • X-rays may show a fracture or retained tooth fragments. • Urgent surgical exploration and debridement is recommended. ∘ Pus contains proteolytic enzymes and toxins that degrade glycosaminoglycans, causing rapid articular destruction. • Surgery requires wide exposure of the zone of trauma. • Wound swabs are taken for culture. • The zone of trauma is examined while the hand is put through a range of motion. • Affected joints are opened and articular surfaces inspected. • Loose fragments of bone and cartilage are removed. • Following irrigation, the wound is left open. • Have a low threshold for further debridement if symptoms do not improve. ∘ Persistent symptoms may indicate osteomyelitis. Dog • Involve puncture wounds from canine teeth; other teeth shear and tear. The Upper Limb 353 • Common aerobic pathogens: ∘ Pasteurella canis ∘ Streptococci ∘ Staphylococci • Common anaerobic pathogens: ∘ Fusobacterium ∘ Porphyromonas ∘ Prevotella ∘ Propionibacterium. Cat • Fine, sharp teeth capable of penetrating bone and joint capsules. • Similar organisms to those found in dog bites, except that Pasteurella multocida is the most common aerobic pathogen. Acute paronychia • • • • Infection of the soft tissue fold around the nail. Most common hand infection. Risk factors: nail biting, manicures, hangnails. Collections should be drained by either: ∘ Separating the nail from the nail fold; or ∘ Incision over the collection. Chronic paronychia • • • • Chronic inflammatory condition with thickened cuticle and nail grooving. Common in people with constantly moist hands, e.g. dishwashers and bartenders. Causative organism is often Candida albicans. Treatment is challenging; may consist of: ∘ Nail removal and topical antifungal and steroid cream. ∘ Surgery to marsupialise the eponychium. Felon Closed-space infection of the finger pulp. Usually the result of a penetrating wound. Abscess formation results in pain and erythema. A high lateral drainage incision is advocated: ∘ Scar lies away from the pulp. ∘ Prevents disruption of the volar fat pad. ∘ Minimises risk of NVB damage. ∘ Gives access to break down the fascial septa in the fingertip. • Inadequately treated infections may result in: ∘ Osteomyelitis ∘ Septic arthritis ∘ Flexor sheath infections ∘ Tender scars on the finger pulp. • • • • 354 Chapter 5 Herpetic whitlow • • • • • • • Superficial herpes simplex virus infection of the hand. Common in dentists, who are exposed to the virus. Presents with throbbing pain, followed by vesicular lesions. Diagnosis can be confirmed with a Tzanck smear and viral cultures. Infection is self-limiting, lasting approximately 2 weeks. Surgical drainage is not indicated – there is a risk of bacterial superinfection. The virus can lie dormant and reactivate years after initial infection. Flexor sheath infections • Usually occur following penetrating injury. ∘ The flexor sheath of the thumb is in continuity with the radial bursa. ∘ The flexor sheath of the little finger is in continuity with the ulnar bursa. • Pus in the radial or ulnar bursa can rupture into the space of Parona. ∘ The potential space of Parona lies proximal to the transverse carpal ligament, between FDP and pronator quadratus fascia. • Infections can then spread between the radial and ulnar bursae – a horseshoe abscess. • Kanavel described four cardinal signs of flexor sheath infection: 1 Fusiform swelling of the finger 2 Semi-flexed finger position 3 Tenderness over the course of the flexor sheath 4 Exquisite pain on passive extension. • Infections diagnosed within 24 hours may respond to elevation and intravenous antibiotics. • Most require surgical drainage and irrigation of the sheath. • Can be performed by an open or closed technique. ∘ Open technique: decompression of the finger along its length. ∘ Closed technique: irrigation through incisions at the A1 and A5 pulleys. – A catheter may be left in situ so irrigation can be continued post-operatively. • Complications include tendon adhesion and tendon necrosis. • Late presentation of a suppurative infection can lead to the loss of the finger. Palm infections • The palm contains three potential spaces deep to the flexor tendons. • Normally empty; become enlarged only in abnormal situations. • Collections should be drained as a surgical emergency. The thenar space • Radial to the oblique septum, which extends from palmar fascia to the 3rd metacarpal. • Flexor sheath infections of thumb, index or middle finger may rupture into this space. The midpalmar space • Ulnar to the oblique septum; continuous with the deep space of Parona. The Upper Limb 355 • Its ulnar border is the hypothenar septum, which extends from palmar fascia to the 5th metacarpal. • Flexor sheath infections of the middle or ring finger may rupture into this space. The hypothenar space • Rarely involved in hand infections. • Small space between the hypothenar septum and hypothenar muscles. Dorsal hand infections • The dorsal hand contains three spaces: The dorsal subcutaneous space • Large potential space overlying the entire dorsum. • Communicates in the finger webs with the potential space beneath palmar fascia. ∘ Palmar infections can spread to the dorsum via this route. The dorsal subaponeurotic space • Lies between extensor tendons and metacarpal periosteum. The interdigital webspaces • Areas of loose connective tissue between the fingers. • Infection can track volar and dorsal, known as ‘collar stud abscesses’. ∘ Important to treat both aspects of the hand in such cases. ∘ Incisions crossing the webspace should be avoided. Complex regional pain syndrome (CRPS) • A debilitating condition characterised by continuing pain in a limb, in association with sensory, vasomotor, sudomotor, motor and dystrophic changes. ∘ Commonly results from injury to that limb, which need not be severe. Epidemiology • Incidence varies from 5.5 to 26.2 per 100,000 person years. ∘ Affects up to 28% of patients after distal radius fractures. – Anecdotally associated with an overly tight cast. ∘ Affects 4.5–40% after Dupuytren’s fasciectomy; 3.2–5% after carpal tunnel decompression. • Females affected three times more frequently than males. Clinical features • Pain is usually the most prominent symptom. • Associated with limb dysfunction and psychological distress. • Patients may have neglect-like symptoms – feeling that the limb is ‘alien’. 356 Chapter 5 • Examination may reveal trophic changes: ∘ Stiffness ∘ Oedema ∘ Osteopenia ∘ Atrophy of the hair, nails or skin ∘ Hypertrophy of the skin (hyperkeratosis) has also been described. • CRPS is divided into two types: ∘ Type 1 occurs in the absence of a lesion to a major nerve. – Formerly known as reflex sympathetic dystrophy or Sudeck’s atrophy. ∘ Type 2 occurs in the presence of a lesion to a major nerve. – Formerly known as causalgia. • The nature of the lesion in type 2 should be clarified and treated as required. • Otherwise, management is the same for both types. Definitions of terminology • • • • • • • • • Pain: unpleasant perception associated with actual or potential cell damage. Analgesia: absence of pain in response to an insult that should produce pain. Paraesthesia: spontaneous abnormal sensation. Dysaesthesia: unpleasant spontaneous abnormal sensation. Allodynia: perception of a non-painful stimulus as painful. Hyperalgesia: increased response to a stimulus that is normally painful. Hyperaesthesia: increased sensitivity to a non-painful stimulus. Hyperpathia: exaggerated and very painful response to stimulation. Neuropathic pain: pain initiated by a lesion or dysfunction of the peripheral or central nervous system. Diagnosis • Based on clinical criteria alone. • The Budapest criteria have been adopted by the UK guidelines. • A diagnosis of CRPS must meet the following criteria: 1 Continuing pain, disproportionate to any inciting event. 2 At least one symptom in three of the four following categories: – Sensory: hyperaesthesia ± allodynia. – Vasomotor: temperature asymmetry ± skin colour changes/asymmetry. – Sudomotor/Oedema: oedema ± sweating changes/asymmetry. – Motor/Trophic: decreased range of motion ± motor dysfunction (weakness, tremor, dystonia) ± trophic changes (hair, nail, skin). 3 At least one sign at the time of evaluation in two or more categories: – Sensory: hyperalgesia to pinprick ± allodynia to light touch ± temperature sensation ± deep somatic pressure ± joint movement. – Vasomotor: temperature asymmetry (>1∘ C) ± skin colour changes/asymmetry. – Sudomotor/Oedema: oedema ± sweating changes/asymmetry. – Motor/Trophic: decreased range of motion ± motor dysfunction (weakness, tremor, dystonia) ± trophic changes (hair, nail, skin). 4 No other diagnosis better explains the signs and symptoms. The Upper Limb 357 Treatment • CRPS is an idiopathic condition; there is no medical cure. • Early diagnosis and treatment aims to avoid secondary problems of disuse and psychological consequences of undiagnosed chronic pain. • Early physiotherapy and early movement may prevent progression. • Patients are best managed in specialist pain or rehabilitation clinics. • Multidisciplinary treatment includes the four ‘pillars of intervention’: 1. Patient information and education • Reassurance that CRPS is a recognised condition. • CRPS is not an indicator of substandard surgery. • Symptoms are usually transient and respond well to physiotherapy. 2. Pain relief • Aims to support an exercise/therapy programme. • Trauma-related pain is treated with paracetamol, co-codamol or non-steroidal antiinflammatory drugs (NSAIDs). • Consider neuropathic medication, e.g. amitriptyline or pregabalin. • Avoid opiate analgesia unless advised by a specialist pain clinic. • Pamidronate may be given as a single intravenous dose within 6 months. ∘ Limits osteopenia; its mechanism of pain relief is not known. 3. Physical and vocational rehabilitation • Emphasis on restoring normal function through goal-based exercises. • May involve desensitisation exercises and mirror visual feedback. • Avoid slings and splints. 4. Psychological intervention • Management of anxiety and depression. • Exploration of external influences or perverse incentives. • Cognitive behavioural therapy can provide coping strategies. • Topical lignocaine, capsaicin patches and guanethidine sympathetic block is considered for non-responders. • Surgery is avoided because it inflicts an additional painful stimulus. • Amputation is not a treatment – symptoms often recur as phantom CRPS. ∘ Amputation may be necessary for life-threatening infection. • For most patients, CRPS is transient, lasting up to 18 months. • 15% have unrelenting pain and physical impairment beyond 5 years. Nerve compression • Compression can occur at any point from the spine to the end organ. • Factors other than simple compression can produce symptoms: ∘ Traction ∘ Tethering 358 Chapter 5 ∘ ∘ Excessive excursion Ischaemia. • Typical symptoms: ∘ Pain, which can radiate proximally and distally. ∘ Sensory disturbance – tingling, numbness, clumsiness. ∘ Motor disturbance with weakness. • Signs that may be present: ∘ Tenderness over the nerve, either direct (palpation) or indirect (provocation tests). ∘ Tinel’s sign at the site of compression or just proximal to it. ∘ Sensory changes, impaired 2PD. ∘ Motor changes – wasting, postural changes or weakness. Classification 1 Anatomical ∘ Nerves are compressed at predictable pinch points. 2 Postural ∘ Repeated movements that increase compression, e.g. wrist flexion. 3 Developmental ∘ Abnormal structures can tether, stretch or compress. 4 Inflammatory ∘ Synovitis can cause carpal tunnel syndrome. 5 Traumatic ∘ Acute compression with fractures, dislocations or crush. 6 Post-surgical ∘ Oedema, haematoma or CRPS. 7 Metabolic ∘ Excessive water retention and fluid shifts. ∘ Carpal tunnel syndrome is commoner in diabetes, myxoedema (hypothyroidism or Graves’ disease), acromegaly and pregnancy. 8 Swellings ∘ Behave as space-occupying lesions, e.g. neurofibroma, ganglia. 9 Iatrogenic ∘ Improper patient positioning during general anaesthesia. ∘ Misplaced sutures, plates or screws. The median nerve and its branches • Formed by the lateral and medial cords of the brachial plexus. • Contains fibres from all roots of the brachial plexus (C5-T1). • Typically compressed at: 1 Wrist – carpal tunnel syndrome. 2 Elbow – pronator syndrome. • The anterior interosseous branch can be compressed in the forearm. ∘ Known as anterior interosseous syndrome. The Upper Limb 359 Carpal tunnel syndrome • Most common nerve compression syndrome in the upper limb. • Occurs in up to 10% of the population. • Female to male preponderance of 3:1; peaks between 45 and 60 years. Anatomy • The carpal tunnel is an inelastic fibro-osseous tunnel. ∘ The base is formed by the bony carpal arch. ∘ This is bridged by the transverse carpal ligament or flexor retinaculum. • The transverse carpal ligament is attached to: ∘ Radial side: scaphoid tubercle and ridge of the trapezium ∘ Ulnar side: hook of hamate and pisiform. • Some consider the flexor retinaculum and transverse carpal ligament to be separate structures: ∘ The proximal retinaculum is the continuation of the deep antebrachial fascia. ∘ The central part is the transverse carpal ligament. ∘ The distal part is the aponeurosis between thenar and hypothenar muscles. • The palmar cutaneous branch pierces deep antebrachial fascia within 1 cm of the wrist to enter the palm superficial to the flexor retinaculum. • Lanz classified variations of the recurrent motor branch. ∘ Most commonly, it divides from the median nerve distal to the flexor retinaculum in an extraligamentous pattern (46%). – It is subligamentous in 31% and transligamentous in 23%. ∘ Rarely, the motor branch divides from the ulnar side of the median nerve. Kaplan’s cardinal line • A surface guide to structures encountered during carpal tunnel surgery. • There is no consensus definition of the precise location of the line. ∘ Kaplan himself gave three different definitions in various publications. • A reasonable definition places the line from the apex of the first webspace to the hook of hamate, parallel to the proximal palmar crease. • It is said to localise deep structures as follows: 1 Its intersection with a line from the radial border of the middle finger: motor branch of median. 2 Its intersection with a line from the radial border of the ring finger: superficial palmar arch and distal margin of transverse carpal ligament. • Recent anatomical studies show these surface markings are approximate. Aetiology • Reduction in the size of the tunnel: ∘ Acromegaly ∘ Trauma, e.g. carpal dislocations ∘ Osteophytes due to OA. 360 Chapter 5 • Increase in the volume of the contents: ∘ Swellings, e.g. ganglia, lipomas ∘ Inflammation, e.g. rheumatoid, gout, amyloidosis ∘ Metabolic, e.g. pregnancy, diabetes, the mucopolysaccharidoses. • Congenital causes are rare: ∘ Persistent median artery ∘ Abnormally long FDS muscle belly ∘ Abnormally proximal lumbrical origin ∘ Abnormal muscles or tendons, e.g. palmaris profundus or a reversed palmaris. Symptoms • Most common is numbness or paraesthesia in the nerve’s distribution in the hand. ∘ The palm is usually spared. ∘ Ulnar-innervated fingers may also be symptomatic. • Clumsiness and dropping items. ∘ Due to loss of sensation, proprioception and strength. • Pain may extend proximally as far as the shoulder. ∘ Possibly due to generalised neuritis or referred pain from the cervical roots. • Night pain and waking. ∘ Due to swelling and flexed posture of the wrist during sleep. ∘ Relieved by shaking the hand and placing it in a dependant position. Signs • Altered sensation in the median nerve’s distribution. ∘ The palm may not be spared if there is anomalous anatomy. • Wasting and weakness of thenar muscles is a late sign. ∘ APB should be specifically tested. Tinel’s sign • Positive if percussion over the tunnel or just proximal to it induces paraesthesiae within the nerve’s distribution. Phalen’s test • Positive if wrist flexion for up to 1 minute induces numbness or paraesthesiae within the nerve’s distribution. Reverse Phalen’s test • Used when the conventional Phalen’s test has failed to produce paraesthesiae. ∘ Similar to Phalen’s, except the wrist is extended. Carpal compression test (Durkan’s sign) • Positive if pressure over the carpal tunnel induces paraesthesiae. ∘ Used in patients who cannot flex or extend their wrists. The Upper Limb 361 Investigations Electrophysiology • Can confirm clinical suspicion or localise the site of compression: ∘ Prolonged distal motor latencies (most sensitive finding). ∘ Slowed sensory nerve conduction velocity. ∘ Reduced compound action potential amplitudes. ∘ Retrograde degeneration – slowed conduction in the forearm. ∘ Electromyography (EMG) findings – fibrillation potentials, sharp waves or electrical silence. • Positive results are useful; normal studies do not rule out compression. Imaging • Indicated for bony carpal derangement or space-occupying lesions. Treatment Non-operative treatments • For mild or intermittent CTS, or transient aetiology, e.g. pregnancy: ∘ Wrist splint in slight dorsiflexion. ∘ NSAIDs. ∘ Steroid injection into the carpal tunnel. – Relief in 80%, but only 20% are asymptomatic at one year. Operative treatments • Surgical release of the flexor retinaculum: ∘ Open technique ∘ Limited incision technique ∘ Endoscopic technique. • First line of management for weakness, wasting, constant numbness or increased distal latencies. • Some recommend these ancillary procedures: ∘ Neurolysis of the median nerve. ∘ Separate decompression of the motor branch. ∘ Transfer of PL to APB (Camitz opponensplasty) for thenar wasting. ∘ Synovectomy for synovial proliferation. • Sequelae and complications of surgery: ∘ Rapid improvement in sensation for most. ∘ Decreased grip strength; usually improves over 3–9 months. ∘ Scar tenderness, possibly due to neuroma of the palmar cutaneous branch. ∘ Pillar pain – pain over thenar and hypothenar eminences – Common in the early post-operative period; resolves over 6–12 months. • May be due to inflammation at the cut edges of the ligament. • May be due to altered geometry of the carpus. ∘ Small risk of nerve injury, particularly if there is abnormal anatomy. 362 Chapter 5 Pronator syndrome • Uncommon but may be mistaken for CTS. • Nerve conduction studies (NCS) are usually normal – compression is intermittent. • The median nerve may be compressed at these sites: 1 Lacertus fibrosus – This is the biceps aponeurosis. – Symptoms are reproduced by resisted elbow flexion and supination. 2 Pronator teres – Symptoms are reproduced by resisted pronation with the elbow extended. 3 Under the arch of the proximal edge of FDS – Symptoms are reproduced by resisted flexion of the middle finger PIPJ. 4 Uncommonly, beneath the ligament of Struthers. – Arises from a lateral supracondylar process on the lower humerus. Symptoms and signs • Similar to CTS, except: ∘ Altered sensation in the palm. ∘ Negative Tinel’s at the wrist, but may be positive over the forearm. ∘ No nocturnal symptoms. ∘ NCS normal at the wrist. • Phalen’s test is paradoxically positive in up to 50%. ∘ May be explained by the ‘double crush’ phenomenon: – Compression of an axon at one location makes it more sensitive to compression at another location due to impaired axoplasm flow. Treatment • Splintage in pronation and slight wrist flexion for 6–12 weeks. • Surgical decompression if splintage fails; recovery is unpredictable. Anterior interosseous syndrome • The anterior interosseous nerve is purely motor and innervates: ∘ FPL ∘ FDP to index and middle fingers ∘ Pronator quadratus. • Sites of compression: ∘ Tendinous bands in the deep surface of pronator teres or FDS. ∘ Accessory muscles: Gantzer’s muscle (accessory head of FPL), connections between FDS and FDP. ∘ Vascular: aberrant radial artery, thrombosis of ulnar collateral vessels. Symptoms and signs • Pain – even ‘pure’ motor nerves carry afferent information from muscles and joints. The Upper Limb 363 • Weakness of pinch. ∘ Inability to make an ‘O’ sign with thumb and index finger due to paralysis of FPL and index FDP. • Weakness of pronation compared to the normal side. ∘ Accentuated by testing with the elbow flexed to reduce the effect of pronator teres. Treatment • Spontaneous resolution can occur after 6–12 weeks of conservative treatment. • Otherwise, surgical decompression of the offending cause. The ulnar nerve • Arises from the medial cord of the brachial plexus. • Contains fibres from spinal roots C8 and T1 with occasional fibres from C7. • Typically compressed at: 1 Elbow – cubital tunnel syndrome. 2 Wrist – Guyon’s canal. • Symptoms may also arise from nerve root compression in the neck. Cubital tunnel syndrome • Second most common upper limb compression neuropathy. • The cubital tunnel is formed by: ∘ Walls: medial epicondyle of humerus and olecranon. ∘ Floor: elbow joint capsule and medial collateral ligament. ∘ Roof: deep fascia of FCU and arcuate ligament of Osborne. – Osborne described transverse fibres between the medial epicondyle and olecranon. • Contiguous with the aponeurosis between the two heads of FCU. • The ulnar nerve elongates 5–8 mm with elbow flexion. • Elbow flexion changes the cubital tunnel from round to oval. ∘ Increases intraneural pressure up to six times normal. ∘ Likely a major cause of nocturnal symptoms. • Anatomical causes of cubital tunnel syndrome: 1 Arcade of Struthers. – Fascial band from the medial intermuscular septum to medial head of triceps. – Approximately 8 cm proximal to medial epicondyle. – Different from the ligament of Struthers (see ‘The median nerve and its branches’). 2 Hypertrophy of the medial head of triceps. 3 Aponeurosis between the two heads of FCU. 4 Cubitus valgus (lateral deviation of the elbow joint). – Can cause symptoms years after distal humerus fracture. • Known as ‘tardy ulnar nerve palsy’ in this context. – May be inherited as an exaggerated carrying angle. 5 Swellings, e.g. lipomas, ganglia, osteophytes. 364 Chapter 5 6 Recurrent dislocation of the nerve. – Can dislocate over the medial epicondyle on elbow flexion. – Produces a neuritis and exposes the nerve to direct trauma. 7 Abnormal muscles: anconeus epitrochlearis. Symptoms and signs • Ill-defined pain in the upper limb. • Paraesthesia and numbness of the ulnar 1 1∕2 fingers. • Weakness of adductor pollicis and first dorsal interosseous. • Wasting and clawing are signs of well-established ulnar neuropathy. • Froment’s sign is flexion of the thumb IPJ when attempting to hold a piece of paper in the first webspace against resistance. • Wartenberg’s sign is inability to adduct the extended little finger due to the unopposed action of EDM. • The Pitres–Testut sign is inability to abduct the middle finger from side to side with the hand flat on a tabletop. • Tinel’s sign is usually present over the cubital tunnel. • Elbow flexion producing pain and paraesthesiae is virtually diagnostic. • Palsy of FCU and the ulnar FDPs is rare, despite being innervated distal to the tunnel. • NCS can help localise the site of compression, but are often negative. Treatment • Trial of splintage with the elbow flexed <90∘ . • Avoiding postures and activities that stress or stretch the nerve. • Surgical decompression may be needed: ∘ Results are less predictable than for CTS. ∘ Care is taken to preserve the medial cutaneous nerves of the forearm. • The best method of decompressing the nerve is controversial: 1 Simple in situ decompression. 2 Anterior transposition of the nerve (subcutaneous or submuscular). 3 Medial epicondylectomy. Compression of the ulnar nerve in Guyon’s canal • Rare cause of ulnar nerve entrapment. • Guyon’s canal is a triangular space superficial to the flexor retinaculum. • Runs from the proximal edge of the transverse carpal ligament to the fibrous arch of the hypothenar muscle origin. • It does not have distinct walls – its boundaries change throughout its course. • The pisohamate ligament forms the floor; volar carpal ligament forms the roof. ∘ Traversed by the ulnar artery and nerve; artery is radial to nerve. ∘ The nerve divides into superficial and deep branches within the canal. – Superficial branch supplies palmaris brevis and sensation to ulnar 1 1∕2 digits. – Deep branch supplies all intrinsic muscles not supplied by median nerve. The Upper Limb 365 • Guyon’s canal is divided into zones that help localise lesions clinically: ∘ Zone 1: proximal to the nerve’s bifurcation – mixed motor and sensory deficit. ∘ Zone 2: deep motor branch – pure motor loss. ∘ Zone 3: superficial branch – pure sensory changes. • Usually caused by: ∘ Acute trauma: hook of hamate fracture. ∘ Repetitive trauma: hypothenar hammer syndrome. ∘ Space-occupying lesions: ganglia, lipomas, aneurysms. ∘ Anomalous muscles: accessory palmaris longus (PL), abnormal origin of hypothenar muscles. Symptoms and signs • Pain in the hand or forearm. • Associated weakness, paraesthesiae and numbness. ∘ Findings depend on which branches are involved. • Motor signs: ∘ Wasting and weakness, especially first dorsal interosseous muscle. ∘ Ulnar claw – MCPJ hypertension and IPJ flexion of little and ring fingers. ∘ Weakness of key pinch. ∘ Positive Froment’s, Wartenberg’s and Pitres–Testut signs. • Sensory signs: ∘ Positive Tinel’s sign. ∘ Decreased sensation in the ulnar 1 1∕2 fingers. ∘ Preserved dorsal cutaneous branch. Management • Diagnosis is usually confirmed by NCS. • MRI may demonstrate any space-occupying lesions. • Wrist splints are suitable for acute cases of localised trauma, e.g. long-distance cyclists. • Guyon’s canal can be decompressed through a carpal tunnel incision, extended proximally into the wrist. Four common communicating branches • Variable connections exist between median and ulnar nerves. • They give rise to paradoxical patterns of motor and sensory disturbance. • ‘Anastomosis’ is used below when it is the prevailing term in the literature. ∘ Some argue it is an inappropriate term because there is no ‘stoma’. Martin–Gruber anastomosis • Median to ulnar connection in the forearm. • Low median nerve injury may have no effect on intrinsic muscles because they are entirely supplied by the ulnar nerve. ∘ Similarly, a low ulnar nerve injury would paralyse all intrinsics. • Reported to occur in 5–40%. 366 Chapter 5 Marinacci communication • Ulnar to median connection in the forearm. • High median nerve injury may not produce the expected intrinsic paralysis because it receives its motor fibres from the ulnar nerve more distally. ∘ Similarly, a high ulnar nerve injury would paralyse all intrinsics. • Reported to occur in 1–17%. Riche–Cannieu anastomosis • Ulnar to median connection in the hand. • Between the deep motor branch of ulnar and recurrent motor branch of median nerve. • The ulnar nerve may supply some or all median innervated muscles. • Reported to occur in up to 83%. Berrettini branch • Superficial palmar connection between ulnar and median nerves. • A pure sensory connection at the distal edge of the transverse carpal ligament. • Most at risk during endoscopic carpal tunnel decompression. ∘ Division results in numbness of the third web. • Reported to occur in up to 100% of individuals. The radial nerve and its branches • Continuation of the posterior cord of the brachial plexus. ∘ Largest branch of the plexus. ∘ Contains fibres from all roots (C5-T1). • Passes through the triangular space to the spiral (radial) groove of the humerus. ∘ The triangular space is formed by humerus, long head of triceps and teres major. • Pierces the lateral intermuscular septum 10–12 cm proximal to the lateral epicondyle to enter the anterior compartment of upper arm. ∘ Lies between brachialis and brachioradialis; runs distally over the radiocapitellar joint. • Radial nerve is typically compressed at the elbow – radial tunnel syndrome. • The radial tunnel is approximately 5 cm long, bounded by: ∘ Brachialis and biceps tendon medially. ∘ Mobile wad of extensor muscles anterolaterally. ∘ Begins just proximal to the radiocapitellar joint (joint capsule forms the floor). ∘ Ends at the distal edge of supinator. • The nerve bifurcates at the radiocapitellar joint: 1 Superficial radial nerve – A sensory nerve; travels on the deep surface of brachioradialis. – Can be compressed at the wrist – Wartenberg’s syndrome. 2 The posterior interosseous nerve (PIN) – Predominantly motor nerve – travels deep into the forearm. – Can be compressed in the forearm. Radial tunnel syndrome • The radial nerve can be compressed at the elbow by: 1 Fibrous bands tethering the nerve to the radiohumeral joint. The Upper Limb 2 Leash of Henry. – A ‘fan’ of radial recurrent vessels passing across the nerve. 3 Tendinous margin of extensor carpi radialis brevis (ECRB). 4 Arcade of Frohse (pronounced Fro-zer). – Fibrous band on the surface of supinator. • These produce intermittent compression when: ∘ Wrist flexed and pronated with elbow extended. ∘ Wrist extended or supinated against resistance. • Activities involving these repetitive movements may cause symptoms. Symptoms and signs • Pain is the predominant symptom. ∘ Localised to the extensor muscle mass just distal to the elbow. ∘ May radiate to the dorsal wrist. ∘ Aching that worsens throughout the day with use of the arm. ∘ May be confused with tennis elbow (lateral epicondylitis). • In radial tunnel syndrome, there is no motor or sensory loss. ∘ Decreased grip strength may be due to pain. • Tenderness is localised over the radial nerve in the radial tunnel. ∘ Differentiated from tennis elbow by palpating the lateral epicondyle: – This will be more tender than palpation of the nerve in tennis elbow. • The middle finger test is more painful in radial tunnel syndrome: ∘ Involves resisted extension of the middle finger with an extended elbow. – This pushes the tendinous edge of ECRB onto the radial nerve. • Resisted supination of the extended arm can produce radial tunnel pain. ∘ Elbow extension minimises biceps but maximises supinator contraction. • NCS are unreliable because compression is intermittent. Treatment • Non-surgical treatments are trialled first: ∘ Lifestyle modifications to avoid repetitive movements. ∘ Splint to minimise wrist flexion. ∘ Steroid injection to temporarily eliminate any tennis elbow. • Surgical decompression involves release of: 1 Medial border of ECRB 2 Arcade of Frohse 3 Leash of Henry 4 Superficial head of supinator. • Performed through anterior, posterior or brachioradialis splitting approach. Posterior interosseous nerve syndrome • PIN is motor to most of the forearm extensor musculature. • Terminates in the base of the 4th extensor compartment as a small sensory branch. • Causes include: ∘ Trauma 367 368 ∘ ∘ ∘ ∘ Chapter 5 – Dislocation of the elbow – Fracture or dislocation of the radial head. Inflammation – Rheumatoid synovitis of the radiohumeral joint and subluxation of the radial head. Swellings – Ganglia and lipomas. Anatomical, postural and occupational causes – As described for radial tunnel syndrome. Iatrogenic – After injection for tennis elbow. – After plating of radius fractures. Symptoms and signs • Pain is similar to that of radial tunnel syndrome. • Accompanied/replaced by weakness of finger, thumb and wrist extensors. ∘ This differentiates it from radial tunnel syndrome. • Sensory disturbance does not occur. ∘ Dysaesthesia indicates a more proximal radial nerve lesion. • Tenderness may be present over the nerve. • Tinel’s sign may be positive. • Wrist extension may be preserved, but classically is radially deviated. ∘ The branch to ECRL is given off proximal to the PIN. Treatment • Splintage to support joints and muscles to protect function. ∘ Many cases recover with time. • Persistent cases require decompression as for radial tunnel. Wartenberg’s syndrome • Compression of the superficial branch of the radial nerve. • Wartenberg originally termed it ‘cheiralgia paraesthetica’. • Not to be confused with Wartenberg’s sign (ulnar nerve). • The nerve emerges from beneath the brachioradialis tendon, 6–8 cm proximal to the radial styloid. • Splits into two or more sensory branches to the dorsum of the radial 3 1∕2 fingers. • The nerve may be pinched between brachioradialis and ECRL in pronation. ∘ Most have a history of repetitive pronation–supination. • May also be compressed by bracelets, handcuffs or watches. Symptoms and signs • Paraesthesiae, pain and numbness in the nerve’s territory; may radiate proximally. • Tinel’s sign may be positive. • Easily confused with de Quervain’s disease. ∘ Both may give a positive Finkelstein’s test. The Upper Limb ∘ ∘ 369 There is no sensory disturbance with de Quervain’s. Pain to percussion in de Quervain’s is not a true Tinel’s sign. Treatment • Non-operative measures are usually successful: ∘ Avoid the inciting jewellery or repetitive supination–pronation. ∘ Steroid injection at the site of entrapment. • Surgical decompression is occasionally required: ∘ Approach just volar to the brachioradialis musculotendinous junction. ∘ The nerve may be entrapped in brachioradialis tendon, margin of ECRL, or fascia between the two. Thoracic outlet syndrome (TOS) • TOS is compression of the subclavian artery and brachial plexus as they traverse the thoracic outlet. • The outlet has been partitioned into three: 1 Interscalene triangle: – First rib inferiorly – Scalenus anterior anteriorly – Scalenus medius posteriorly. 2 Costoclavicular triangle: – Clavicle anteriorly – First rib medially – Superior border of scapula posteriorly. 3 Subcoracoid or pectoralis minor space: – Just deep to pectoralis minor tendon. • T1 root and the lower trunk of the brachial plexus are most frequently affected. • Causes of TOS: ∘ Cervical ribs. – Present in 0.5% of normal individuals; 10% of patients with TOS. ∘ Rudimentary first ribs. ∘ Tendinous or ligamentous bands associated with the scalenes. ∘ Bone or soft tissue tumours. ∘ Trauma, e.g. fractured clavicle. ∘ Extremes of posture – exaggerated ‘shoulders back’ or slumped shoulders. Classification • Wilbourn classification: ∘ Vascular – Arterial (1–2%) – Venous (2–3%) ∘ Neurogenic – ‘True’ (1:1,000,000) – ‘Disputed’ (97%). • ‘True’ neurogenic causes have positive NCS. 370 Chapter 5 History • Symptoms depend on whether compression is vascular, neurogenic or a combination. • Provoked by carrying heavy loads or working with arms overhead. • Neurogenic symptoms are present in 90% of cases: ∘ Pain. – Dull ache, nagging, gnawing, burning or throbbing. – Usually in the shoulder girdle, neck and medial upper arm. – May radiate to the hand. ∘ Paraesthesia and numbness. – Common in C8 and T1 dermatomes. ∘ Weakness. – Weakness and wasting of T1-innervated intrinsics of the hand. • Vascular symptoms and signs are rarer (10%): ∘ Claudication ∘ Splinter haemorrhages and digital emboli ∘ Venous engorgement ∘ Cold intolerance ∘ Colour changes in the fingers and Raynaud’s phenomenon. Examination • Begin distal to proximal because, once triggered, symptoms of TOS may persist for some time. • Sensation ∘ Differentiate ulnar nerve compression from TOS: – TOS has additional sensory changes in the medial cutaneous nerves of the arm and forearm. ∘ Pain or paraesthesiae with percussion over the posterior triangle of the neck. ∘ Differentiate cervical root compression from TOS: – Symptoms on lateral neck flexion towards the affected side are due to spinal root compression. – Symptoms on lateral neck flexion away from the affected side are due to TOS. • Motor function ∘ Weakness and wasting of ulnar and median innervated hand intrinsics. • Vascular compromise ∘ Colour or temperature difference between the normal and abnormal side. ∘ Lower blood pressure in the affected limb. ∘ A subclavian artery thrill may be palpable; a bruit may be audible in the posterior triangle. • Specific provocation tests ∘ Roos’ test, also known as the 3-minute elevated arm stress test (EAST), is said to be most reliable: – Patient seated, arms abducted to 90∘ , elbows flexed to 90∘ . – Patient asked to open and close hands repeatedly while keeping shoulders gently braced backwards. – Patients with TOS are unable to complete this test due to symptom recurrence. The Upper Limb Investigations • Chest and cervical spine X-ray. ∘ ‘True’ neurogenic TOS is usually caused by a structural abnormality. – CT or MRI scanning may be helpful for these cases. • Invasive vascular imaging is indicated for acute vascular obstruction. ∘ Otherwise, non-invasive colour duplex sonography. • ‘Disputed’ neurogenic cases do not require imaging. • Electrophysiological studies are recommended for all cases. ∘ May show slowed nerve conduction across the supraclavicular fossa. ∘ Can also rule out distal nerve compression. Management • Non-operative management for ‘disputed’ TOS. ∘ Physiotherapy, lifestyle and occupational modifications. ∘ Analgesics, NSAIDs, muscle relaxants, antidepressants, gabapentin. ∘ 50–100% of patients improve with non-operative management. • Surgery is indicated for vascular or progressive neurological dysfunction: ∘ Excision or release of anomalous anatomy ∘ Resection of first rib ∘ Excision of anterior and middle scalenes ∘ Neurolysis of the involved supraclavicular brachial plexus ∘ Release of pectoralis minor tendon. • The approach is based on surgeon preference: ∘ Supraclavicular (Adson) ∘ Transaxillary (Roos) ∘ Posterior parascapular (Claggett) ∘ Transthoracic. Cervical root compression • May be confused with peripheral nerve compression. • Pain in the upper limb is the major complaint. ∘ Exacerbated by extremes of neck movement or sneezing. ∘ May radiate into the occiput. • Sensory and motor changes show a spinal root distribution. • Diminished reflexes: ∘ Biceps (predominantly C5) ∘ Brachioradialis (predominantly C6) ∘ Triceps (predominantly C7). Traumatic brachial plexus injury • Classically affects young males 15–25 years old. 371 372 Chapter 5 • Narakas’ rule of ‘seven seventies’ gives an impression of the epidemiology: 1 70% are road traffic collisions (RTCs). 2 70% of the RTCs are motorcycles or bicycles. 3 70% of the cycle riders have multiple injuries. 4 70% of the injuries in cycle riders are supraclavicular. 5 70% of the supraclavicular injuries have at least one root avulsed. 6 70% of the avulsed roots are lower roots (C7, C8, T1). 7 70% of the avulsed roots are associated with chronic pain. Anatomy • The brachial plexus is a large network of nerves to the upper limb. • Spinal nerves arise from the spinal cord by two roots: 1 Ventral, containing motor (efferent) fibres from nerve cell bodies in the ventral horn. 2 Dorsal, containing sensory (afferent) fibres from nerve cell bodies in the dorsal root ganglion. • Spinal nerves divide into two branches: 1 A small dorsal ramus, supplying nerves to the back. 2 A larger ventral ramus, supplying nerves to the limbs and trunk. • After emerging from the spinal foramina, the ventral rami of C5-8 and T1 form the brachial plexus. • The plexus may be ‘prefixed’ or ‘postfixed’ by contributions from C4 or T2, respectively. ∘ This can give paradoxical examination findings. Arrangement of the spinal cord Grey matter Dorsal root Dorsal root ganglion Dorsal ramus Spinal nerve White matter Ventral root • The plexus is divided into five anatomical zones: 1 Roots, between scalenus anterior and scalenus medius 2 Trunks, in the posterior triangle of the neck 3 Divisions, behind the clavicle 4 Cords, in the axilla 5 Branches, throughout the plexus. – Note that ‘roots’ in this context refers to ‘ventral rami’. Ventral ramus The Upper Limb • • • • • • • • 373 The plexus is also arbitrarily divided into supra-, retro- and infraclavicular parts. C5 and C6 merge to form the upper trunk. C7 continues as the middle trunk. C8 and T1 merge to form the lower trunk. All trunks divide into anterior and posterior divisions. All posterior divisions merge to form the posterior cord. Anterior divisions of upper and middle trunks merge to form the lateral cord. The anterior division of the lower trunk continues as the medial cord. Brachial plexus A C C5 E F Anterior Middle Posterior L M N O An te rio r r D rio te C6 Lateral s Po Upper ter ior C7 H I G J Po s C8 P Posterior Lower Anterior Medial T1 K B Roots Trunks Divisions A. Dorsal scapular B. Long thoracic C. Suprascapular D. Nerve to subclavius E. Lateral pectoral F. Musculocutaneous G. Median H. Medial pectoral I. Medial cutaneous nerve of the arm J. Medial cutaneous nerve of the forearm K. Ulnar nerve L. Upper subscapular M. Thoracodorsal N. Lower subscapular O. Axillary P. Radial Cords and branches • Branches can be categorised by their origin: Branches from the roots (2) • Dorsal scapular (C5) – rhomboids, levator scapulae. • Long thoracic (C567) – serratus anterior. Branches from the upper trunk (2) • Suprascapular (C56) – supraspinatus, infraspinatus. • Nerve to subclavius (C56) – subclavius. Branches from the lateral cord (3) • Lateral pectoral (C567) – clavicular pectoralis major, pectoralis minor. • Musculocutaneous (C567) – coracobrachialis, biceps, brachialis. • Median (C5678, T1) – formed by medial and lateral cords. 374 Chapter 5 Branches from the medial cord (5) • Medial pectoral (C8, T1) – sternocostal pectoralis major, pectoralis minor. • Medial cutaneous nerve of the arm (C8, T1). • Medial cutaneous nerve of the forearm (C8, T1). • Ulnar (C8, T1) – some forearm flexors, hand intrinsics. • Median (C5678, T1) – formed by medial and lateral cords. Branches from the posterior cord (5) • Upper subscapular (C56) – subscapularis. • Thoracodorsal (C678) – latissimus dorsi. • Lower subscapular (C56) – subscapularis, teres major. • Axillary (C56) – deltoid, teres minor. • Radial (C5678, T1) – triceps, anconeus, brachioradialis, forearm extensor muscles. Mechanisms of injury • As with all trauma, the magnitude of energy transfer determines severity of injury and prognosis. • High energy trauma can cause multiple levels of injury. Traction • Most common mechanism; causes stretch, rupture and avulsion. • Often a widespread longitudinal zone of injury. • Low energy: neurapraxia, axonotmesis. • High energy: ruptures, avulsions of roots from spinal cord. C5-6 injury • 15% injure C56 roots, or the upper trunk. • Known as Erb’s palsy or Erb–Duchenne palsy. • Affects shoulder stability, elbow flexion, forearm supination, sensation. C5-7 injury • 35% injure C567 roots, or the upper and middle trunks. • In addition to C56 deficits, there may be weakness of elbow, wrist and finger extension. ∘ The contribution of C7 is variable. C8-T1 injury • 10% injure C8 and T1 roots, or the lower trunk. • Known as Klumpke’s palsy or Dejerine-Klumpke palsy. • Affects hand intrinsics, and possibly extrinsics too, sensation. ∘ The degree of weakness depends on the variable contribution of C7. • Involvement of the lower roots can result in Horner’s syndrome. C5-T1 injury • 75% of supraclavicular injuries are pan-plexus. • Patients have an insensate flail arm. The Upper Limb 375 Crush • Caused by direct blunt trauma to the neck and arm. • The plexus is crushed between clavicle and first rib. Compression • Coexisting vascular and bony injury can compress the plexus. Open injury • Sharp (blades, glass) and blunt (fans, chainsaws, bullets, teeth) penetrating trauma directly damage the plexus. • Up to a third have concomitant vascular injury. Classification • Sunderland and Seddon classifications address nerve injury. • Leffert’s classification addresses aetiology: ∘ Type I: Open (usually due to stabbing) ∘ Type II: Closed (usually due to RTCs) – IIa: Supraclavicular • Preganglionic • Postganglionic – IIb: Infraclavicular – IIc: Combined ∘ Type III: Radiotherapy ∘ Type IV: Obstetric – IVa: Upper roots (Erb’s palsy) – IVb: Lower roots (Klumpke’s palsy) – IVc: Mixed. • Most other classifications (Chuang, Millesi, Terzis) broadly address: 1 Whether the lesion is preganglionic or postganglionic. – The former has a poorer prognosis. 2 Whether the lesion is supra- or infraclavicular. – The former has a poorer prognosis. – Traction injury affects the supraclavicular plexus twice as often as infraclavicular. Assessment • Given the potential mechanisms of injury, an ATLS-style assessment is done. • Plexus assessment aims to determine the location and severity of injury. ∘ This helps with prognostication and treatment planning. History • Mechanism of injury: high or low energy, blunt or penetrating. • Associated injury: paraesthesiae or weakness in other limbs. • Severe pain in an insensate limb is suggestive of deafferentation. ∘ Seen in patients with root avulsions. 376 Chapter 5 Examination • Associated injuries: ∘ Vascular: pulseless limb, haemorrhage, haematoma, pseudoaneurysm ∘ Apical lung injury ∘ Upper limb fractures ∘ Scapulothoracic dissociation ∘ Rib fractures with pneumo- or haemothorax, lung contusion ∘ Spinal fractures with cord injury ∘ Traumatic brain injury. • Plexus examination is best done systematically: ∘ Motor and sensory deficits are documented. ∘ Documentation is facilitated by illustrated proformas. • Note the attitude of the arm, muscle wasting (not acutely), winged scapula. • Establish the stability and passive range of motion of each joint. • Assess the major distal plexus branches. • More proximal injury is suggested by weakness of: ∘ Latissimus dorsi (posterior cord) ∘ Sternocostal head of pectoralis major (medial cord) ∘ Clavicular head of pectoralis major (lateral cord). • Dermatomal sensory loss is also suggestive of proximal injury. • Suprascapular nerve involvement may indicate upper trunk injury. • Features suggestive of preganglionic injury: 1 Loss of dorsal scapular and long thoracic nerve, consistent with proximal injury. 2 Horner’s syndrome, associated with T1 root avulsion. 3 Absence of Tinel’s sign in the posterior triangle of the neck. 4 Atrophy of dorsal spinal muscles, innervated by the dorsal rami. • Features suggestive of postganglionic injury: 1 Percussion tenderness in supra- or infraclavicular areas. 2 Absence of sweating in the territory of the injured nerve. 3 Advancing Tinel’s sign, suggestive of recovering injury. • Integrity of the accessory nerve (XI) is verified by testing trapezius. ∘ Often used for nerve transfer but may have been injured. • Lower limb is examined for evidence of cervical myelopathy. • Acute Brown-Séquard syndrome is rare, but associated with plexus avulsion: ∘ Essentially a functional disruption of one-half of the spinal cord: – Ipsilateral upper motor neuron lesion below the level of injury. – Ipsilateral deficit of vibration sensation and proprioception. – Contralateral deficit of pain and temperature sensation. ∘ Urgent cervical spine MRI is indicated to exclude reversible compression of the spinal cord due to extradural or subdural haematoma. Imaging Plain X-ray • Chest radiographs in inspiration and expiration show associated trauma, e.g. rib fractures, and activity of the diaphragm. The Upper Limb 377 • Cervical spine radiographs may show fractures of the transverse processes. ∘ Transverse processes are connected to nerve roots by deep cervical fascia. ∘ Displaced fractures are markers of potential root avulsion. • Shoulder and upper limb radiographs show other fractures and dislocations. CT myelography • An invasive test involving intrathecal injection of contrast medium. • Considered the most reliable method of detecting root avulsions. • It can be performed from 1 month following injury. ∘ Allows time for pseudomeningoceles to form – indicators of root avulsion. – Pseudomeningoceles are abnormal collections of CSF that communicate with the subarachnoid space. – Not true meningoceles – they are not enclosed by meninges. MRI • MR technology is supplanting CT as the modality of choice. • Advantages: ∘ Detection of associated spinal cord injury. ∘ Contrast enhancement within intact nerve roots, suggesting neurapraxia. ∘ Visualisation of the postganglionic plexus with ‘diffusion-weighted neurography’. ∘ MR myelography using ‘fast imaging employing steady-state acquisition’ (FIESTA). – Non-invasive; excellent visualisation of nerve rootlets exiting the cord. Electrophysiological studies • Include EMG and NCS. • Used from 3 to 4 weeks post-injury, after Wallerian degeneration. • EMG evaluates activity of muscles at rest and with activity. ∘ Denervation produces characteristic fibrillation potentials at rest. ∘ Voluntary motor unit potentials are reduced or absent. ∘ EMG changes in paraspinal muscles suggest proximal injury. ∘ EMG also demonstrates subclinical evidence of recovery. • NCS, particularly sensory nerve action potentials (SNAPs), can help localise the injury. ∘ Motor axons undergo Wallerian degeneration regardless of the level of injury because their cell bodies are in the spinal cord. ∘ However, sensory axons do not undergo Wallerian degeneration after preganglionic injury because axons remain connected to cell bodies in the dorsal root ganglion. – The SNAP is therefore preserved. – Sensory loss occurs because neurons are not connected to the CNS. ∘ Postganglionic injuries result in Wallerian degeneration – the SNAP is therefore lost. • Results should be correlated with clinical and imaging findings: ∘ Absent SNAPs can be due to isolated postganglionic injury. ∘ However, combined pre- and postganglionic injury gives similar NCS findings. Management • Other more life-threatening injuries are treated first. 378 Chapter 5 Non-operative • Used when spontaneous recovery expected. • Also complements definitive surgical treatment. • Multidisciplinary approach: physiotherapy, occupational therapy, pain specialists, prosthetists. ∘ Splints and range of motion exercises prevent contractures. ∘ Facilitate early return to work – an important part of recovery. Operative • Mainstay of treatment for plexus injuries. • Controversial area – there are many valid tactics used by different surgeons. Timing of repair • Principles: ∘ Patients who recover spontaneously have better outcomes. ∘ Surgery is indicated if there is no hope of spontaneous recovery. ∘ If surgery is required, outcomes are better the sooner surgery is done. • These principles produce two conflicting philosophies: 1 Repair early (within days), accepting the risk of operating on patients that would have recovered spontaneously, given time. 2 Repair after several months, allowing time to assess spontaneous recovery but potentially compromising surgical outcomes. In general: • Open injuries are treated within days of injury. • Surgery is delayed if there is a chance of spontaneous recovery. ∘ The length of delay is balanced with the better outcomes of earlier surgery. • Reconstruction after 1 year is generally unsuccessful due to degeneration of motor nerve end plates. Surgical approaches 1 Supraclavicular ∘ Parallel to the clavicle or posterior border of sternocleidomastoid. ∘ Gives access to roots, trunks and suprascapular nerve. ∘ Osteotomy of the clavicle improves exposure. 2 Infraclavicular ∘ Incision usually in the deltopectoral groove. ∘ Gives access to cords and branches. ∘ Pectoralis minor is detached from the coracoid process to improve exposure. 3 Combined ∘ Incisions may be joined across the clavicle, or kept separate. Intraoperative assessment • Many employ intraoperative electrophysiological testing. The Upper Limb 379 • Somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) establish whether a spinal nerve is connected to the central nervous system. ∘ This rules out preganglionic injury, confirming suitability for grafting. • Nerve action potentials (NAPs) evaluate function in a segment of nerve. ∘ Stimulating and recording electrodes are placed either side of a lesion. ∘ Helps decide whether to resect and graft a neuroma-in-continuity. Surgical strategies • Ideally, surgery would re-establish the continuity of the plexus. • Not always possible because: 1 Avulsed roots cannot be replanted successfully into the spinal cord. 2 Autologous donor nerve tissue is limited. • Priorities for surgical treatment are based on: ∘ Functional significance. ∘ Likelihood of success (most success proximally). ∘ Available options for secondary reconstruction. C5-6 injury 1 Shoulder control – axillary and suprascapular reinnervation. 2 Elbow flexion – musculocutaneous reinnervation. 3 Thoracobrachial pinch – thoracodorsal and pectoral reinnervation. C5-7 injury • As for C5-6 injury plus: 1 Wrist extension 2 Elbow extension. C8-T1 injury • Reinnervation is unlikely to succeed due to the long reinnervation distances. • Rely on tendon transfers and free functioning muscle transfer (FFMT). • Aim to restore: 1 Flexion/extension of fingers and thumb 2 Opposition 3 Correction of claw deformity. Pan-plexus injury • In order of importance, priorities are: 1 Elbow flexion 2 Shoulder control 3 Hand sensation 4 Wrist and finger flexion 5 Wrist and finger extension 6 Intrinsic hand muscle function. 380 Chapter 5 Surgical techniques Neurolysis • Indicated for neuroma-in-continuity with adequate NAPs. • External neurolysis separates epineurium from surrounding tissue. • Internal neurolysis separates nerve fascicles from intraneural scar. Nerve repair • Acute repair is possible following sharp transection of a nerve. Nerve grafting • For bridging postganglionic ruptures or neuromas-in-continuity without NAPs. • Common donor nerves: ∘ Sural ∘ Superficial radial ∘ Medial cutaneous nerves of the arm and forearm ∘ Lateral cutaneous nerve of the forearm ∘ Dorsal ulnar cutaneous ∘ Saphenous. • Larger nerves can be taken as vascularised nerve grafts if not functioning. ∘ The ulnar and radial nerves are often used this way. Nerve transfer • A functioning nerve can be transferred to fulfil a more important function. • Used for preganglionic injuries, where nerve grafting is not an option. • Also used for some postganglionic injuries where regrowth distances are long. ∘ Donor nerves close to the target muscle are selected to minimise the time to reinnervation. • Transferred nerves may be intraplexal or extraplexal: ∘ Spinal accessory (cranial nerve XI) – Often used for the suprascapular nerve. ∘ Branch to long head of triceps – Often used for the axillary nerve – the Leechavengvongs (Bangkok) procedure. ∘ Ulnar nerve fascicle – A fascicle predominantly supplying FCU is selected. – Coapted to the biceps branch of musculocutaneous. – Known as the Oberlin I transfer. ∘ Median nerve fascicle – Used in combination with the Oberlin I for elbow flexion. – Double neurotisation improves outcomes. – A fascicle predominantly supplying FCR is selected. – Coapted to the brachialis branch of musculocutaneous. – Known as the Mackinnon transfer, or Oberlin II. ∘ Intercostal nerves – Traditionally used for the musculocutaneous nerve in pan-plexus injury. – The third to sixth intercostal nerves give longest length. – May be unusable after rib fractures or intercostal drain placement. The Upper Limb ∘ 381 Contralateral C7 – Controversial donor nerve because it risks functional loss in the uninjured arm. – Has been used to reinnervate shoulder, elbow and hand. – A vascularised ulnar nerve graft is used to connect C7 to its targets. – Not popular outside Asia due to neuropathic pain and suboptimal results. Free functioning muscle transfer (FFMT) • Suitable muscles should have: 1 Vascular pedicle amenable to free transfer. 2 Sufficient length, contraction and force to fulfil its new function. 3 Acceptable donor site morbidity. • Common muscles: latissimus dorsi, gracilis, rectus femoris. • FFMT can be used acutely (Doi procedure): 1 Elbow flexion with finger and wrist extension is achieved with one gracilis. – Gracilis is attached to the clavicle, routed under brachioradialis, inset into extensor digitorum tendons. – Anastomosed to the thoracoacromial artery, cephalic vein and accessory nerve. 2 A second gracilis is transferred for finger flexion. – Gracilis is attached to the second and third ribs and FDP tendons. – Anastomosed to thoracodorsal vessels and intercostal nerves 5 and 6. Secondary procedures • Salvage for: ∘ Failure of shoulder reinnervation. ∘ Painful chronic glenohumeral subluxation. ∘ Lack of elbow flexion. Tendon transfers • Require part of the plexus to be at least grade M4 power. • For rotator cuff or deltoid function: ∘ Upper trapezius ∘ Lower trapezius ∘ Latissimus dorsi ∘ Pectoralis major. • For elbow flexion: ∘ Pectoralis major ∘ Triceps ∘ Latissimus dorsi ∘ Sternocleidomastoid ∘ Steindler flexorplasty – Transposes the common flexor origin to a more proximal and anterior position on the humerus. – Increases those muscles’ moment arm for elbow flexion. 382 Chapter 5 Free functioning muscle transfer • Secondary FFMT if suitable vessels and nerves available. Joint fusions • Shoulder arthrodesis is viewed by many as a marker of failure. ∘ Requires intact trapezius and rhomboids ∘ These power shoulder movement at the scapulothoracic joint following fusion. • Wrist arthrodesis when no tendon transfers available. ∘ Potentiates the effect of finger flexion by placing the wrist in a functional position. Neuropathic pain • Resection and grafting of neuromas can provide relief. • Neurosurgical treatment following root avulsion: ∘ Radiofrequency ablation of the dorsal root entry zone. ∘ Spinal cord and deep brain stimulation. Obstetric brachial plexus palsy An injury noticed at the time of delivery. Affects 0.5–3 per 1000 live births. Attributed to increased neck-shoulder angle during parturition. Also caused by crush due to forceps or fractures of the clavicle and humerus. Presents a mixture of neurapraxia, partial or complete rupture, and root avulsion. Common patterns of palsy: C5-6 (46%) and C5-7 (29%). ∘ Usually postganglionic injuries. • C8-T1 and pan-plexus injuries are rarer; usually have a preganglionic element. • Non-plexus causes of palsy: ∘ Brain injury ∘ Limb fractures ∘ Congenital causes, e.g. arthrogryposis, synostosis. • • • • • • Risk factors Mother • Diabetes mellitus (increased risk of fetal macrosomia). • Previous obstetric complications. • Multiparous pregnancy. Child • Large baby, >500 g above average birth weight. • Breech presentation. Parturition • Prolonged second stage of labour. • Need for instrumentation, either forceps or vacuum assisted. • Shoulder or head dystocia. The Upper Limb 383 Classification • Narakas: ∘ Group 1: C5-6; paralysis of the shoulder and elbow flexion. – Spontaneous recovery >80%. ∘ Group 2: C5-7; as above with wrist drop. – Spontaneous recovery >60%. ∘ Group 3: C5-T1; complete flaccid paralysis. – Spontaneous recovery 30–50%. – Many have a functional hand. ∘ Group 4: C5-T1; complete flaccid paralysis with Horner’s. – This group carries the worst prognosis. Assessment History • Any predisposing factors listed above. Examination • Posture of the limb: ∘ ‘Waiter’s tip’ – Erb’s palsy. ∘ Claw hand – Klumpke’s palsy (rare in obstetric). ∘ Flexed elbow – isolated C7 (rare). ∘ Flail limb – pan-plexus injury. • Markers of proximal or preganglionic lesions: ∘ Abdominal asymmetry when breathing – phrenic nerve. ∘ Winging scapula – long thoracic nerve. ∘ Horner’s syndrome. • Torticollis can coexist with plexus palsy ∘ May be due to obstetric injury of sternocleidomastoid. ∘ Baby usually looks away from the side of the lesion. • Neonatal reflexes: startle, grasp and asymmetric tonic neck reflex. Investigations • Diaphragm function is assessed by ultrasound. • CT myelography or MRI may show root avulsions. • Electrophysiological tests are less useful in obstetric palsy. Management • Controversial – there is a wide range of acceptable practice. • Most cases are managed non-operatively. ∘ Passive exercises to maintain range of motion until the plexus recovers. • Most agree that surgery is indicated for Narakas group 4, or T1 root avulsion. ∘ There is little consensus on which other patients require surgery. • Repeated examination helps guide treatment: ∘ Partial recovery (at least MRC grade M3) within 2 months usually leads to full recovery by age 2. 384 Chapter 5 ∘ If some biceps and shoulder function has not recovered by 6 months, most recommend reconstruction. • The Hospital for Sick Kids, Toronto, has developed a validated Test Score to guide early treatment: ∘ If satisfactory improvement is made on the Test Score, surgery is postponed for 9 months. ∘ At 9 months, the cookie test is performed. ∘ Involves placing a cookie in the child’s hand and, while holding the humerus to the child’s side, allowing the child to bring the cookie to its mouth by flexing the elbow. ∘ Inability to reach the mouth with the cookie is an indication for surgery. Surgical technique • Principles of surgery are similar to those used in adults, except: ∘ Neurolysis is not as effective for obstetric palsy. ∘ The hand, rather than shoulder, is prioritised. – Unlike adult injuries, nerve grafting and transfer can reinnervate the hand due to shorter regrowth distances. Tendon transfers • • • • Involves moving the insertion of a tendon-muscle unit from one location to another. Historically, performed routinely after nerve injuries when recovery was typically poor. With advancements in nerve repair, tendon transfers are now used more for salvage. Have a major role following tendon or muscle loss and in preventing contractures. General principles • Successful tendon transfer is dependent on: 1 Patient selection 2 Recipient site factors 3 Donor muscle factors 4 Surgical technique. Patient selection • Well motivated • Understands the nature and limitations of surgery • Co-operates with physiotherapy. Recipient site factors • Good soft tissue coverage without active scar formation. • Stable skeleton. • Full range of passive joint motion. • Normal sensation. ∘ Sensory loss reduces the benefit of transfers, particularly opponensplasty. The Upper Limb 385 Donor muscle factors • Factors to consider when choosing which muscle to transfer (‘APOSLE’): Amplitude of motion • Donor muscle should have similar excursion to that which it replaces. ∘ Wrist flexors and extensors: 3 cm. ∘ Finger extensors: 5 cm. ∘ Finger flexors: 7 cm. • The amplitude of donor tendons is increased by: ∘ Freeing fascial tethers. ∘ Tenodesis effect. – Amplitude of a tendon that crosses the wrist is increased by 2–3 cm by full wrist range of motion. • Wrist fusion should be avoided whenever possible. Power and control • The donor muscle should have similar strength to that which it replaces. ∘ Muscles lose at least one motor grade following transfer. • Muscles with MRC motor grade 5 are ideal. • Those with MRC motor grade 4 function acceptably. • Muscles with MRC motor grade ≤3 rarely function well. • Muscles reinnervated following injury are not ideal for transfer. • Some muscles, e.g. brachioradialis, have difficulty adapting to a new function. ∘ Brachioradialis is sometimes called the ‘naughty boy’ of the wrist. • Donor muscles should be under voluntary control. One tendon, one function • Tendon transfers cannot fulfil two different functions simultaneously. • Each transfer is intended to perform a single action, e.g. finger extension. Synergistic action • Muscles that normally act together to produce a composite movement should replace each other whenever possible. ∘ Finger flexion is usually accompanied by synergistic wrist extension. ∘ Finger extension usually accompanied by synergistic wrist flexion. ∘ Transfer of a wrist flexor to a finger extensor is a synergistic transfer. • Synergistic transfers are better integrated into hand use than asynchronous transfers. ∘ They require a shorter period of rehabilitation. Line of pull • Tendon transfers function best when they travel in a straight line. • Deviation around a pulley weakens the transfer. Expendability • Only expendable muscles should be transferred. 386 Chapter 5 • It is important to preserve a wrist flexor when reconstructing wrist and finger extension following radial nerve palsy. Surgical principles 1 Operate in reverse order ∘ Have the recipient site and tunnel ready before raising the muscle. 2 Avoid interference with other structures ∘ Ensure the transfer does not compress nerves. 3 Apply the correct tension ∘ Ideal tension varies between transfers – assess by the tenodesis test. Radial nerve palsy Motor deficits • Wrist extension. • Finger extension. • Radial abduction of thumb. Tendon transfers Classic transfer • PT to ECRB ∘ PT is short so transfer with 2–3 cm of periosteum. • FCU to EDC • PL to EPL. Superficialis transfer • Alternative to the classic transfer; described by Boyes: ∘ PT to ECRL and ECRB ∘ FCR to APL and extensor pollicis brevis (EPB) ∘ FDS middle finger to EDC ∘ FDS ring finger to EIP and EPL – FDS is tunnelled through the interosseous membrane. Median nerve palsy • Classified as high or low based on the origin of the anterior interosseous nerve. Motor deficits Low median nerve lesions • Thumb opposition. ∘ APB is most reliably supplied by the median nerve. ∘ FPB and OP may be partially supplied by the ulnar nerve. – Some low median nerve palsies have adequate thumb opposition. High median nerve lesions • Thumb opposition, forearm pronation, thumb and index flexion. • Middle finger flexion is usually possible due to crossover from the ulnar nerve. The Upper Limb 387 Tendon transfers • Opponensplasties are transfers that restore opposition: The FDS opponensplasty • The Royle-Thompson technique divides FDS IV distally. ∘ The tendon is re-routed across the palm ∘ The angle between the ulnar border of the palmar aponeurosis and distal edge of the transverse carpal ligament is used as a pulley. ∘ Transferred to the APB insertion. • The Bunnell technique re-routes FDS through a pulley made from a distally based strip of FCU tendon at the pisiform. ∘ FDS is passed dorsal to the thumb MCPJ and secured to the ulnar base of proximal phalanx. The extensor indicis transfer • EI is re-routed around the ulnar side of the wrist, proximal to extensor retinaculum. • Sutured to APB insertion and/or MCPJ capsule, and EPL. The Camitz transfer • PL is lengthened by including a strip of palmar fascia. • Attached to APB insertion. • Used in long-standing median nerve palsy. ∘ Combined with carpal tunnel release in older patients. ∘ Its line of pull restores palmar abduction rather than true opposition. The Huber transfer • ADM detached from its origin and insertion, preserving its proximal neurovascular supply. • Turned through 180∘ on its long axis (like turning the page of a book) and transposed across the palm through a subcutaneous tunnel. • Attached to the APB insertion. Tendon transfers for high median nerve lesions • In addition to opponensplasty, high lesions may require: ∘ ECRL to index finger FDP. ∘ BR to FPL. – These rely on the tenodesis effect for much of their range of motion. • Side-to-side buddying of the index FDP to the conjoint middle, ring and little finger FDPs produces good range of motion, but of low power. Ulnar nerve palsy Motor deficits • • • • Thumb adduction. Dorsal interossei – weakness of finger ABduction (‘DAB’). Palmar interossei – weakness of finger ADduction (‘PAD’). Ulnar clawing. ∘ Combination of MCPJ hyperextension and IPJ flexion. 388 Chapter 5 ∘ Caused by weak intrinsics (interossei and lumbricals), which normally cause MCPJ flexion and IPJ extension. ∘ Allows the unopposed pull of EDC on the MCPJs, and of FDS and FDP on the IPJs. • Low ulnar palsy results in a more pronounced claw than higher lesions. ∘ This phenomenon is known as the ulnar paradox. ∘ Low lesions cause a greater claw because the ulnar-innervated long flexors to the ring and little fingers produce IPJ flexion. ∘ In high lesions, these muscles are denervated and cannot flex the IPJs. Tendon transfers Loss of thumb adduction • ECRB or BR is extended with tendon graft, passed through the third intermetacarpal space and inserted into the radial side of the thumb MCPJ. • Alternatively, FDS III or IV can be detached distally and transferred to the adductor tubercle of the thumb, via a pulley of aponeurosis in the mid-palm. Claw deformity • Limiting MCPJ hyperextension controls clawing if the IPJs passively extend with MCPJ flexion. • The Zancolli lasso technique is commonly used: ∘ FDS of each clawed finger is divided at its insertion. ∘ Passed through a transverse incision in the A1 pulley. ∘ The tendon is looped over the A1 pulley and sutured to itself in the distal palm. ∘ FDS then becomes a flexor of the MCPJ. • The Stiles–Bunnell procedure transfers slips of FDS through the lumbrical canals to the radial and ulnar lateral bands. ∘ It is a complex procedure, prone to adhesion and tendon imbalance. • The Brand transfer uses ECRL or ECRB, elongated with plantaris tendon grafts, inserted into the lateral bands in the finger. Dupuytren’s disease • A benign fibroproliferative disease of the hand characterised by contraction of palmar and/or digital fascia. Epidemiology • Prevalence is highest in Northern Europeans, particularly those of Scottish, Icelandic or Norwegian descent. • Incidence increases with age. • In the United Kingdom, overall prevalence is 4%; affects 20% of over 65 year olds. • Overall three times commoner in males. ∘ After age 70 the sex distribution is equal. • Strong hereditary disposition. • Rare in the Far East and Africa. ∘ Exception: Japan – similar incidence to Northern Europe. ∘ However, it is milder disease with few contractures. The Upper Limb 389 Aetiology • Cause is unknown. • Population studies show smoking and heavy alcohol consumption increases risk. • Also commoner in diabetics (Type I more so than Type II). ∘ Diabetics tend to have milder DD – more nodules than contractures. • Onset of DD may be related to acute injury, infection or surgery to the same limb. ∘ Thought that trauma hastens the onset of DD in predisposed individuals. • Anticonvulsants and manual labour are associated only loosely with DD. Pathophysiology • Diseased tissue is classically described in two forms: 1 Nodules – Palpable subcutaneous lumps, usually fixed to skin and palmar fascia. 2 Cords – Organised, relatively hypocellular collagen structures. • Predominantly type III collagen; normal palmar fascia is largely type I. • Nodules were thought to be the active, contractile component of DD while cords were the static, acellular end-product of nodule contraction. ∘ However, it is now known DD is a mix of static and dynamic contractile elements found throughout palmar and digital fascia. • The key cell in DD is the myofibroblast, which shares features of both fibroblasts and smooth muscle cells. Genetics • Clear genetic predisposition to DD. ∘ Autosomal dominant with variable penetrance. ∘ Siblings of DD patients are >3× more likely to develop the disease. • No single polymorphism has been identified as the sole cause. • Generally, genes regulating collagen breakdown are inhibited: ∘ Superoxide dismutase, matrix metalloproteinase-3, cysteine dioxygenase 1. • Conversely, genes promoting development of collagen in epidermis are upregulated: ∘ Examples include α-smooth muscle actin, β-1 integrin, collagen I, V and VIII, fibronectin, laminin. Environment • Trauma, microvascular angiopathy and ischaemia thought to be important. ∘ Microangiopathy is exacerbated by smoking, trauma and alcohol. ∘ Causes local tissue ischaemia, releasing free radicals. • Free radicals stimulate IL-1, which increases TGF-β, FGF, EGF and PDGF. ∘ These stimulate myofibroblast differentiation, proliferation and contraction. • This biochemical environment favours production of type III collagen over type I. Anatomy of the palmar fascia • Normal fascial structures are bands. • Diseased fascial structures are cords. ∘ Mnemonic: remember b comes before c in the alphabet. 390 Chapter 5 • Palmar fascia consists of: ∘ Palmar aponeurosis ∘ Hypothenar aponeurosis ∘ Thenar aponeurosis ∘ Digital fascia. Palmar aponeurosis • Composed of three layers with distinct orientations: 1 Longitudinal fibres 2 Vertical fibres 3 Transverse fibres. Longitudinal fibres • Triangular layer; fans out distally into four pretendinous bands. • Pretendinous bands bifurcate to pass either side of the flexor tendons. • They have three layers of insertion: 1 Superficially into dermis via Grapow vertical fibres. 2 Middle layer, passes dorsal to the NVBs as the spiral band of Gosset. 3 Deeply into flexor and extensor mechanism near A1 pulley, via McGrouther fibres. Vertical fibres • Consist of the septa of Legueu and Juvara. • Eight vertical septa form seven fibro-osseous compartments: ∘ Four for paired FDS and FDP tendons. ∘ Three for common digital NVBs and associated lumbrical. Transverse fibres • Transverse ligament of the palmar aponeurosis (Skoog’s ligament) proximally. • Natatory ligament distally. ∘ Skoog’s ligament is said to be spared in DD. • Many advocate preserving Skoog’s ligament during fasciectomy. ∘ It is a landmark for the NVBs, which lie deep to it, in the event of reoperation. Hypothenar aponeurosis • Consists of: 1 Hypothenar muscle fascia 2 Pretendinous band of the little finger 3 ADM soft tissue confluence 4 Pisiform ligamentous complex. Thenar aponeurosis • Consists of: 1 Thenar muscle fascia 2 Pretendinous band of the thumb The Upper Limb 391 3 Proximal commissural ligament (thumb equivalent of Skoog’s ligament) 4 Distal commissural ligament (thumb equivalent of natatory ligament). Digital fascia • The digital NVB is surrounded by four structures: 1 Grayson’s ligaments volarly, from flexor sheath to skin. 2 Cleland’s ligaments dorsally, from phalanges to skin. 3 Lateral digital sheet laterally, a continuation of the spiral band and natatory ligament. 4 Retrovascular fascia of Thomine medially. • Cleland’s ligaments are typically spared in DD. Pathological anatomy • • • • • • • • • • • • • DD transforms normal fascial bands into contracted, thickened cords. Leads to joint contracture, stiffness, decreased skin mobility and distortion. Skin thickening results from disease in superficial Grapow fibres. Skin pitting results from disease in the superficial layer of pretendinous cords. In the palm, pretendinous cords result in MCPJ contracture. Diseased septa of Legueu and Juvara can cause painful trigger finger. Natatory cords cause webspace contractures. Spiral cords cause MCPJ and PIPJ contracture. In the fingers, the spiral cord originates from four structures: 1 Middle layer of the pretendinous band 2 Spiral band 3 Lateral digital sheet 4 Grayson’s ligament. Spiral cords are in fact straight. ∘ As they contract, they cause the NVBs to spiral medially and superficially. – A more correct term might be spiral nerve and artery. ∘ Spiral cords increase risk of iatrogenic neurovascular injury. – Skin incisions should be made through dermis, not onto the cord. ∘ The location and orientation of the NVBs can then be ascertained by blunt dissection. In the little finger, a cord may arise from the musculotendinous junction of ADM. ∘ The ADM cord is superficial to the NVB and does not displace it. A central cord is an extension of the pretendinous cord in the finger. ∘ Attaches to periosteum of the middle phalanx and flexor sheath distal to PIPJ. ∘ Causes PIPJ contracture but does not displace the NVB. A lateral cord arises from the lateral digital sheet; can cause PIPJ and DIPJ contracture. ∘ A retrovascular cord may combine with a lateral cord in recurrent DD to cause DIPJ hyperextension contracture. Clinical presentation • Common signs include: ∘ Skin thickening ∘ Skin pitting 392 Chapter 5 ∘ ∘ ∘ Nodules Cords Progressive flexion contracture. • The most commonly affected finger is the ring, then little, middle, index and thumb. • Ectopic disease may be found outside the palmar fascia: ∘ Garrod’s pads on the dorsum of PIPJs affect 2–44%. ∘ Penile fibromatosis (Peyronie’s disease) affects 2–4%. ∘ Plantar fibromatosis (Ledderhose’s disease) affects 5–20%. Dupuytren’s diathesis • Concept proposed by Hueston. • Describes features in patients with increased disease severity and recurrence risk: 1 Bilateral palmar lesions 2 Family history of DD (one or more affected parent/sibling) 3 Ectopic lesions 4 Ethnicity (North European). • These criteria have recently been updated and now include: 1 Male sex 2 Age at onset <50 years old. • DD patients with all six diathesis factors have recurrence risk of 71%. • DD patients with no diathesis factors have recurrence risk of 23%. Indications for treatment • Based on British Society for Surgery of the Hand (BSSH) guidelines. • They classify DD into mild, moderate and severe. Mild • No functional problems, no contracture or MCPJ contracture <30∘ . ∘ Observation, with follow-up in 6–12 months. Moderate • Functional problems or MCPJ contracture 30∘ –60∘ ± PIPJ contracture <30∘ ± first webspace contracture. ∘ Consider needle fasciotomy for isolated MCPJ contracture ∘ Consider collagenase ∘ Limited fasciectomy. Severe • Severe contracture MCPJ >60∘ and PIPJ >30∘ . ∘ Limited fasciectomy ∘ Dermofasciectomy. • In addition to absolute degrees of contracture, rate of progression is important. ∘ Usually more rapid in young patients with aggressive disease. • Hueston’s tabletop test is a useful guide for surgical intervention: ∘ Positive when fingers cannot be placed palm down in a flat position on a tabletop. The Upper Limb 393 • Mild flexion of MCPJs is not an indication for surgery. ∘ MCPJ collateral ligaments are stretched in a flexed position. • In contrast, the PIPJ volar plate and capsule shorten in a flexed position. ∘ Allows them to contract over time, resulting in fixed flexion deformity. ∘ PIPJ contracture is therefore a stronger indication for surgery. • Patients with greater contracture pre-operatively, particularly of the PIPJ, usually have incomplete correction and higher complication rates. Management of the disease Non-surgical Observation • Valid option in many cases – not all DD causes functional problems. • Some cords may not progress to significant contracture. Percutaneous needle fasciotomy • Involves cutting a cord using the bevel of a hypodermic needle. • Complication rates are low if proximal to the distal palmar crease where nerves are deep. • A randomised controlled trial (RCT) compared needle fasciotomy with limited fasciectomy: ∘ Early results were comparable. ∘ Recurrence at 5 years for the needled group was 85%, compared with 24% after surgery. ∘ Average time to recurrence was 3.7 years. Collagenase (Xiapex® ) • Mixture of two enzymes from Clostridium histolyticum that cause lysis and rupture of contracted collagen cords. • Injected percutaneously into a cord, followed by manipulation 24 hours later to facilitate release. • Only one cord at a time should be treated. • Up to three injections to each cord, spaced four weeks apart. • Recent phase III RCTs studied its efficacy in over 200 patients with contractures ≥20∘ . ∘ Trials were named Collagenase Option for Reduction of Dupuytren’s (CORD I and II). • Primary end-point was reduction of contracture to <5∘ in a particular joint. • 77% of treated patients with MCPJ contracture and 40% with PIPJ contracture met the primary end-point, compared with 7.2% and 5.9%, respectively, of placebo patients. • There are no long-term data of recurrence rates. • Flexor tendon rupture has been reported (rare complication). Steroid injection • Some success demonstrated by injecting nodules with triamcinolone. • However, 50% recurrence rate at 1–3 years. Other treatments • These have been shown not to be effective: ∘ Hand therapy and splintage in isolation, i.e. not combined with surgery ∘ Radiotherapy or ultrasound 394 ∘ ∘ ∘ Chapter 5 Interferon 5-fluorouracil Calcium channel blockers, azathioprine, procarbazine and prostaglandin. Surgical Fasciotomy • The involved cord is incised. • Has largely been replaced by percutaneous needle fasciotomy. Segmental fasciectomy • Short segment of diseased fascia is excised as a ‘fire break’. • Less invasive than other fasciectomy techniques. • Trade-off between shorter recovery time and higher recurrence rate. Limited (partial) fasciectomy • Most common operation for DD. • Only the relevant diseased fascia is excised. Total (radical) fasciectomy • All palmar and digital fascia is excised, whether diseased or not. • Originally thought it might prevent recurrence. • Has fallen out of favour due to high complication rates but similar recurrence rates to limited fasciectomy. Dermofasciectomy • Essentially a limited fasciectomy with excision of overlying skin. • The skin defect is usually resurfaced with full thickness skin graft. Other procedures • Amputation • Joint fusion. Complications of surgery • Complication rates are highest when correcting deformity >60∘ . • Wound healing problems (23%) • Pain (18%) • Digital NVB injury (2–4% for primary surgery) • Infection (2%) • CRPS (5%). Recurrence and extension • Recurrence is reappearance of DD within an area of previous surgery. • Extension is appearance of DD in an area not previously operated on. • Recurrence rates quoted in the literature range from 0% to 70%. The Upper Limb 395 Management of the skin • Adequate exposure is essential. • A number of strategies for dealing with the skin have been described: Longitudinal incisions • Skoog described a longitudinal midline volar incision. ∘ Unlikely to inadvertently injure NVBs. ∘ Easily lengthened by incorporating Z-plasties into the closure. • Brunner’s zigzag incision can be closed primarily, or lengthened as Y-V advancement flaps. Transverse incisions • Useful if more than one ray is affected. • Skoog described a transverse palm incision with extensions into the fingers. Skin excision • Skin defects arise following dermofasciectomy or contracture release. • Can be treated with full thickness skin grafts or local flaps. • Wounds up to 1.5 cm in width can be left to heal by secondary intention. ∘ Known as the McCash open palm technique. Management of the PIPJ • Releasing the PIPJ is controversial. ∘ No overwhelming evidence either for or against. • Gentle, continuous, passive extension of the PIPJ may work. ∘ If not successful, surgical release may help. – Some believe post-operative stiffness is unavoidable. • Periarticular structures are released sequentially: 1 Check-rein ligaments 2 Transverse incision of the proximal volar plate 3 Accessory collateral ligaments 4 Flexor tendon sheath. • Full extension may still not be possible due to fibrosis of the NVBs or central slip attenuation. ∘ Both can be addressed by post-operative splintage and hand therapy. ∘ Some place a transarticular K wire to maintain joint extension. Post-operative management • Aim to maintain correction and restore function using combinations of: ∘ Elevation ∘ Splintage immediately after surgery ∘ Physiotherapy and scar management ∘ Dynamic splinting ∘ Static resting night splint for up to 6 months. 396 Chapter 5 Tumours • The most common tumours of the hand are: ∘ Ganglia ∘ Giant cell tumours of the tendon sheath ∘ Epidermoid inclusion cysts ∘ Haemangiomas ∘ Lipomas. • These constitute 95% of all hand tumours. • The remaining 5% are rare; can arise from any constituent tissues: Skin • Benign non-pigmented lesions • Benign pigmented lesions • Malignant non-pigmented lesions • Malignant pigmented lesions. Fat • Lipoma • Angiolipoma • Liposarcoma. Vascular tissue • Haemangioma • Vascular malformations • Glomus tumours • Aneurysms • Angio- or lymphangiosarcoma • Kaposi’s sarcoma. Muscle • Leiomyoma • Leiomyosarcoma • Rhabdomyosarcoma. Fibrous tissue • Dupuytren’s nodules • Dermatofibroma • Dermatofibrosarcoma protuberans • Fibroxanthoma • Fibrosarcoma. Neural tissue • Neuroma • Glioma • Neurofibroma The Upper Limb 397 • Neurilemmoma • Neurosarcoma • Merkel cell tumour. Tendon sheath • Rheumatoid synovitis • Trigger finger nodules • Giant cell tumours of the tendon sheath. Joint • Ganglion. Bone and cartilage • Enchondroma • Osteochondroma • Osteoid osteoma • Simple bone cyst • Aneurysmal bone cyst • Giant cell tumour of bone • Chondrosarcoma • Osteogenic sarcoma • Ewing’s sarcoma • Metastatic tumour. Ganglia • Most common soft tissue tumours of the hand; 50–70% of all lesions. • Three times more common in women than men. • 70% present between age 20 and 40. Pathogenesis • Mucin-filled cysts, usually attached to adjacent joint capsule, tendon or tendon sheath. • Cyst wall comprises compressed collagen fibres without epithelial or synovial lining. • The cause is debatable; proposals include: ∘ Herniation of joint synovium (Eller, 1746). ∘ Embryological remnants of synovial tissue in the joint capsule (Hoeftman, 1876). ∘ Ligament strain resulting in fibrillation of collagen and mucoid degeneration (Ledderhose, 1893). • The latter is most widely accepted, however: ∘ Does not explain why degeneration is so localised and affects young adults. ∘ Does not account for reaccumulation of fluid following aspiration. Location • Common types of ganglion are: 1 Dorsal wrist ganglion 2 Volar wrist ganglion 398 Chapter 5 3 Flexor sheath ganglion (volar retinacular ganglion) 4 Mucous cyst (DIPJ ganglion). • More rarely occur at the following sites: ∘ Over PIPJ ∘ Over extensor tendons ∘ Within Guyon’s canal ∘ Within carpal tunnel ∘ Within bone (intraosseous ganglion). Signs and symptoms • Stiffness. • Dull ache. • Weakness/pain due to carpal involvement or nerve compression. • Many are asymptomatic. • Larger ganglia can be transilluminated. • X-rays may show changes of OA. Differential diagnosis • Carpometacarpal boss ∘ An osteoarthritic spur that develops over the dorsum of the 2nd/3rd CMCJ. ∘ Hard, immobile, occasionally tender lump. ∘ May occur with a dorsal wrist ganglion, or its own small ganglion. ∘ Treatment involves excision of any ganglion and osteophytes. • Extensor digitorum brevis manus ∘ Abnormal accessory muscle. ∘ Aching pain similar to that of a dorsal wrist ganglion may occur. • Extensor tenosynovitis in rheumatoid • Radial artery aneurysm • Malignant soft tissue tumour. Dorsal wrist ganglia • 60–70% of all hand ganglia. • Originate in the region of the scapholunate ligament (SLL). • Can present anywhere on the back of the hand. • Dissection reveals a connection with the SLL via a tortuous stalk. • Occult SLL ganglia are small and difficult to detect clinically. ∘ Cause pain by exerting pressure on the SLL. ∘ Diagnosis usually made by ultrasound or MRI. Treatment Non-surgical management • Reassurance – approximately 40% resolve spontaneously over 6 years. • Aspiration may alleviate symptoms for a variable length of time. ∘ 90% recur following aspiration; 15% recur after three serial aspirations. ∘ Reassures patients of the benign nature of their lump. • No clear evidence that steroid injection affects recurrence. The Upper Limb 399 Surgical excision • Excision should include attachments to joint capsule and wrist ligaments. ∘ Achieved by open surgery or therapeutic arthroscopy. ∘ Mobilse stalk to the joint capsule. ∘ Incise the capsule and tangentially excise the ganglion off the SLL. • Recurrence up to 40% is reported after surgical excision. ∘ Suggests no long-term advantage over observation alone. • Pre-operative pain persists in up to 1∕3 of patients. Volar wrist ganglia • 20% of all hand ganglia. • Originate from the radiocarpal joint or scaphotrapezium-trapezoid (STT) joint. • May be more extensive than suggested on clinical examination. • Most are closely related to the radial artery. Treatment • Similar to dorsal wrist ganglia. • Over half disappear spontaneously within 5 years. • Reported recurrence rate up to 67% following aspiration. ∘ Radial artery is at risk during injection or aspiration. • Considerations for surgery: ∘ Incision may require extension into the carpal tunnel or thumb base. ∘ Protect the radial artery and palmar cutaneous nerve branches. ∘ Reported recurrence rate of 16–42% after surgery. • No difference demonstrated between conservative and surgical management in terms of pain, stiffness or weakness. ∘ Suggests an underlying disorder may be responsible for both ganglion and symptoms. Ganglia of the flexor tendon sheath • Also known as volar retinacular ganglia. • Account for approximately 10% of hand ganglia. • Present as firm, immobile, tender masses at the proximal digital crease. • Arise from the A1 pulley; do not move with the tendon. Treatment • Attempt needle rupture and steroid injection prior to surgery. • Extensile exposure is planned, e.g. Brunner incision. • Excise the ganglion with a small cuff of underlying A1 pulley. Mucous cysts • Mucous cysts are ganglia of the DIPJ. • Usually occur between 5th and 7th decades. • Present with nail grooving, due to pressure on the germinal matrix. ∘ Later a swelling may appear between the distal joint crease and nail. • May have Heberden’s nodes and radiological evidence of DIPJ OA. 400 Chapter 5 Treatment • An L-shaped or curved incision is made over the cyst. • The cyst is traced proximally and excised with a portion of joint capsule. ∘ Osteophytes are treated at the same time. • Preserve the extensor insertion and germinal matrix. • A local flap or skin graft may be required. • If there is severe DIPJ OA, consider primary arthrodesis. Giant cell tumour of the tendon sheath Also known as pigmented villonodular tenosynovitis. Second most common soft tissue tumour of the hand. Although benign, it can be locally invasive. Presents as a painless mass in the fingers, hand or wrist. Usually yellow–brown, multiloculated and not necessarily associated with tendon sheaths. • Treatment is by marginal excision. • Recurrence occurs in approximately 30%. • Malignant transformation has not been described. ∘ However, a primary malignant variant can occur. • • • • • Glomus tumours • Benign vascular hamartomas. • A glomus is an arteriovenous anastomosis involved in thermoregulation. ∘ Many are found in reticular dermis beneath nails and in glabrous skin. • Patients typically present with the triad of: 1 Paroxysmal pain 2 Pinpoint tenderness 3 Cold hypersensitivity. • They resemble small haemangiomas with blue discolouration. • If located in the nail bed, there may be ridging of the nail plate. • The following clinical signs may be present: ∘ Love’s sign – one exquisitely painful spot on palpation with a pinhead. ∘ Hildreth’s sign – reduction of this pain on exsanguination of the affected part with a tourniquet. • Treatment is by surgical excision. • Persistent symptoms may indicate multiple lesions. Bone and cartilage tumours Enchondroma • • • • • An area of abnormal hyaline cartilage formation within bone. Slow growing, benign lesions. Most common primary bone tumour of the hand. Usually located in tubular bones, i.e. the phalanges or metacarpals. Can present as incidental findings on X-ray. The Upper Limb • Occasionally they cause pathological fractures after minimal trauma. • They have a classic radiological appearance: ∘ Central radiolucent area with speckled calcification. ∘ Thinning and expansion of the bony cortex. • Treatment is by curettage. • The residual defect can be bone grafted or left to heal. • Multiple enchondromatosis is known as Ollier’s disease. ∘ In Ollier’s, enchondromas tend to be large, associated with skeletal deformity. ∘ Can differentiate into chondrosarcomas – any sudden change warrants biopsy. • Maffucci’s syndrome is multiple enchondromas associated with vascular anomalies. Osteochondroma • Benign osseous growths with a hyaline cartilage cap. • Risk of malignant transformation is low, particularly in the hand. • Functional impairment due to angular growth disturbance is common. ∘ This is the main indication for surgery. Osteoid osteoma • Benign bone-forming tumours; occur in 2nd or 3rd decades. • Characterised by a constant dull ache, relieved by NSAIDs. • Diagnosis can be difficult because radiological changes are subtle. • Characteristic X-ray appearances: ∘ Lesion <1 cm in diameter. ∘ Small central sclerotic nidus surrounded by a lucent zone. ∘ Sclerotic rim. • Treatment is by curettage with or without bone grafting. Simple (unicameral) bone cysts • Benign cystic lesions of unknown aetiology. • Commonly located in the proximal humerus; rare in the hand. • Treatment options include: ∘ Aspiration and steroid injection. ∘ Curettage. Aneurysmal bone cyst • Rare tumours; tend to occur in the 2nd and 3rd decades. • Although benign, they may invade locally; prone to local recurrence. • Curettage augmented with cryosurgery can be successful. • Larger lesions are best treated by wide excision to minimise recurrence. Arthritis • ‘Rheumatic disorders’ include all painful conditions of the locomotor system. • ‘Rheumatism’ is a lay term for any pain related to the musculoskeletal system. 401 402 Chapter 5 • ‘Arthritis’ is joint disease associated with inflammation. • Arthritic conditions of the upper limb are classified as: 1 Degenerative arthritis – Erosive arthritis (OA). 2 Inflammatory arthritis – Rheumatoid arthritis (RA) – Psoriatic arthritis – Systemic lupus erythematosus (SLE) – Gout – Pseudogout. 3 Infective arthritis – Septic arthritis. Osteoarthritis • A clinical syndrome of joint pain accompanied by varying degrees of functional limitation and reduced quality of life. • Most common cause of disability in the United Kingdom. • Despite the -itis suffix, inflammation is not a prominent feature. ∘ Some prefer the term ‘osteoarthrosis’. Epidemiology • 25% of adults over 50 years of age have radiographic signs of OA of the knee. ∘ Half of these are symptomatic. • 41% of older adults’ hands have radiographic signs of OA. ∘ However, only 3% are symptomatic. • Prevalence of OA is higher in women than in men. Pathogenesis • Characterised by destruction of articular hyaline cartilage. • Adjacent bone is remodelled with osteophyte formation at joint margins. ∘ This process is the natural repair mechanism of synovial joints. ∘ Explains why dramatic X-ray appearances may be asymptomatic. • Sclerosis of periarticular bone is common. ∘ Areas of relative porosity and cyst formation is also seen. • Mild synovitis and inflammatory joint effusions are often present. • Most OA is idiopathic (primary); secondary OA is predisposed to by: ∘ Joint injury ∘ Joint instability ∘ Joint surgery ∘ Inflammatory arthropathy, e.g. rheumatoid, gout ∘ Neuropathic arthropathy, i.e. Charcot joint. Clinical features • A clinical working diagnosis of OA can be made based on: 1 Persistent joint pain that is worse with use The Upper Limb • • • • • • • 403 2 Age > 45 years 3 Morning stiffness lasting no more than half an hour. These features add to the diagnostic certainty: ∘ Inactivity pain and stiffness ∘ Crepitus or bony swelling (due to osteophytes) ∘ Bony swellings of DIPJs (Heberden’s nodes) ∘ Bony swellings of PIPJs (Bouchard’s nodes) ∘ Absence of inflammation, e.g. acutely inflamed joints, raised erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP). ∘ Typical radiological findings: – Joint space narrowing – Osteophyte formation – Subchondral sclerosis and cyst formation – Deformity. Upper limb joints most commonly affected are: ∘ DIPJs ∘ Basal joints of the thumb. IPJ OA has a good prognosis: most are asymptomatic after a few years. In contrast, basal thumb OA causes lasting disability. First CMCJ OA causes ‘shouldering’ at the base of the thumb, giving a square appearance to the palm. ∘ This is due to subluxation of the CMCJ, which may also be adducted. ∘ Leads to compensatory MCPJ hyperextension. Crepitus and pain may be elicited by the ‘grind test’. Radiological changes of basal thumb joints are staged by Eaton: Stage I • Articular contours are normal. • Slight joint space widening due to effusion or laxity of joint ligaments. Stage II • Slight narrowing of trapeziometacarpal joint. • Minimal sclerotic changes of subchondral bone. • Osteophytes or loose bodies <2 mm. • Scaphotrapezial joint is normal. Stage III • Joint space markedly narrowed or obliterated. • Cystic changes, sclerotic bone with varying degrees of dorsal subluxation. • Joint debris >2 mm. • Scaphotrapezial joint is normal. Stage IV • Complete deterioration of trapeziometacarpal joint as in stage III. • Scaphotrapezial joint narrowed with sclerotic and cystic changes. 404 Chapter 5 Treatment Non-operative • Analgesia ∘ Paracetamol ∘ Topical NSAIDs ∘ Systemic NSAIDs ∘ Selective COX-2 inhibitors ∘ Opioids. • Topical capsaicin • Physiotherapy, occupational therapy and splintage. • Avoidance of repetitive grasp, pinch and twisting movements. • Injection of intra-articular corticosteroid or hyaluronans. Operative • Primary target is pain and loss of function, but deformity is also addressed in the process. • There are three basic operations for OA: 1 Arthroplasty – Excision – Interposition – Hemiarthroplasty – Total arthroplasty 2 Arthrodesis 3 Osteotomy. DIPJ • DIPJs are often arthrodesed through a dorsal approach. • Bone surfaces are prepared by cup and cone or flat-angled resection technique. • Options for fixation: ∘ K wires ∘ Interosseous wires, including tension-band wiring ∘ Lag screws, including a Herbert-type screw ∘ Plates, including bioabsorbable implants ∘ External fixation. • DIPJs are fused in 0∘ –20∘ of flexion based on the patient’s needs. PIPJ • PIPJs can be arthrodesed similar to DIPJs. • Suggested fusion angles increase from 40∘ (index) to 55∘ (little), unless there are specific occupational or recreational requirements. • PIPJ arthroplasty is controversial due to historical implant failures. • Swanson-type silicone elastomer replacements are relatively safe in the PIPJ. ∘ However, there is a higher failure rate when used for OA than rheumatoid. • Many combine arthrodesis in the radial digits (for stable lateral pinch) with arthroplasty in the ulnar digits (for range of motion and grip strength). The Upper Limb 405 MCPJ • Arthroplasty is preferred for finger MCPJs. • Arthrodesis is usually a salvage procedure. ∘ Suggested fusion angles range from 25∘ (index) to 40∘ (little). • In contrast, arthrodesis is favoured for the thumb MCPJ: ∘ Classically fused in 10∘ –20∘ flexion, 20∘ pronation, 20∘ abduction. Basal thumb joints • A huge range of procedures has been described. 1 Osteotomy – Abduction-extension osteotomy of the first metacarpal base aims to offload the palmar surface of the CMCJ. – Not often indicated because the OA is usually too advanced at presentation. – May be useful for high demand young adults with early disease. 2 Arthrodesis – Useful for post-traumatic OA, e.g. after Bennett’s fracture malunion in a young manual worker. – Arthrodesis fixes the thumb out of the plane of the hand. – Patients should be warned they will not be able to do press-ups, etc. 3 Arthroplasty – Options include excision and interposition arthroplasty. – Excision arthroplasty – trapeziectomy – is considered the gold standard. – Concerns over post-operative shortening led to various modifications: • Volar beak ligament reconstruction and tendon interposition (LRTI) using APL, PL or FCR. • Distraction to maintain thumb length with K wires. – Nothing has been conclusively shown to be superior to trapeziectomy alone. • The more complex procedures carry a higher complication rate. – Trapeziectomy may fail due to: • Incomplete removal of the trapezium. • Neuromas of the superficial radial nerve. • Collapsing pinch due to MCPJ hyperextension. • Corrected by capsulodesis, sesamoid tenodesis or MCPJ arthrodesis. • Missed pan-trapezial OA. • Gives pain on movement of both the thumb and wrist. • Pure STT OA gives pain on wrist movement only. • Treated by excision of the distal pole of scaphoid. • STT arthrodesis has been described, but it is technically difficult to maintain radial carpal height, eventually leading to radioscaphoid OA. Rheumatoid arthritis • RA is characterised by: 1 Persistent synovitis 2 Systemic inflammation 406 Chapter 5 3 Autoantibodies, particularly: – Rheumatoid factor (RF) – Anti-citrullinated protein antibody (ACPA). Epidemiology • Affects 0.5–1% of adults in developed countries. • Three times more common in females than males. • Incidence peaks at 70 years of age but can affect all ages. • >90% have some degree of hand involvement. • 30% have limitations of normal activity. Aetiology • The precise cause is unknown. Genetics • 50% of the risk of developing RA is attributable to genetic factors. • >30 DNA point mutations are associated with RA. ∘ Only PTPN22 and human leukocyte antigen (HLA) genes have pathogenic implications. Environment • Smoking doubles the risk of developing RA. • Weak association with alcohol, coffee, vitamin D and the oral contraceptive pill. Pathophysiology • Incompletely understood; involves several inflammatory cascades. Inflammation • The final common pathway is synovitis that damages articular cartilage and underlying bone. • Inflammation of tenosynovium weakens and ruptures tendons. • Overproduction of tumour necrosis factor (TNF) by macrophage-like synoviocytes drives synovitis and joint destruction. ∘ IL-1 and IL-6 are also implicated in propagating inflammation. • Fibroblast-like synoviocytes invade cartilage leading to joint destruction. Autoantibodies • 50–80% of RA patients are positive for RF, ACPA or both. ∘ RF is IgM or IgA directed against the Fc portion of IgG. • These form immune complexes that activate the complement cascade, causing inflammation. • Most ACPA-positive patients are also positive for RF. ∘ ACPA positivity is a more specific and sensitive diagnostic marker. ∘ Also a better predictor of poor prognostic features such as joint destruction. The Upper Limb 407 Classification • The American College of Rheumatology (ACR) 1987 criteria were widely used. ∘ However, they have been rendered ineffective by advancements in the treatment of early RA, which can prevent patients from fulfilling the criteria. • New classification criteria for early arthritis were published by the ACR and European League Against Rheumatism (EULAR) in 2010. • Based on a points system, with a cut-off for RA of 6 points. 1 Joint involvement (0–5) – One medium-to-large joint (0) – Two to ten medium-to-large joints (1) – One to three small joints (large joints not counted) (2) – Four to ten small joints (large joints not counted) (3) – More than ten joints (at least one small joint) (5) 2 Serology (0–3) – Negative RF and negative ACPA (0) – Low positive RF or low positive ACPA (2) – High positive RF or high positive ACPA (3) 3 Acute-phase reactants (0–1) – Normal CRP and normal ESR (0) – Abnormal CRP or abnormal ESR (1) 4 Duration of symptoms (0–1) – Less than 6 weeks (0) – 6 weeks or more (1) • Patients can also be classified as having RA if they have typical erosions on X-ray. Extra-articular disease • RA is a systemic disease: Ocular • Scleritis, episcleritis and uveitis. • Sjögren syndrome, which is the triad of: ∘ Dry eyes (keratoconjunctivitis sicca) ∘ Dry mouth (xerostomia) ∘ RA. Neurological • Peripheral neuropathy • Nerve entrapment syndromes • Cervical myelopathy • Mononeuritis multiplex. Haemopoetic • Normocytic-normochromic anaemia of chronic disease. • Felty’s syndrome – RA associated with splenomegaly and neutropenia. 408 Chapter 5 Cardiovascular • Pericarditis • Pericardial effusion • Valvular heart disease • Conduction defects. Pulmonary • Pulmonary nodules • Pleural effusion • Fibrosing alveolitis • Caplan’s syndrome – RA in combination with pneumoconiosis, manifesting as intrapulmonary nodules. Renal • RA does not directly affect the kidneys. • Secondary involvement results from drug side effects and amyloidosis. Cutaneous • Vasculitic rashes and ulcers • Pyoderma gangrenosum • Thinning of skin secondary to steroid administration • Rheumatoid nodules ∘ Soft tissue swellings present in approximately 20% of RA patients. ∘ Occur anywhere but most common over pressure points, e.g. olecranon. Clinical presentation • Joint or systemic symptoms. • The following upper limb joints are frequently affected: ∘ Elbow ∘ Wrist ∘ MCPJs ∘ PIPJs. • Always consider the potential for cervical spine instability. • It is important to record: ∘ Number of tender, swollen joints. ∘ Time period over which symptoms occurred. ∘ Degree of functional impairment. ∘ Numbness, paraesthesiae or weakness. ∘ Whether deformity is fixed or mobile. • Z deformities classically occur in the thumb and wrist, but can occur anywhere. ∘ The Z deformity occurs because when a joint persistently adopts an angulation in one direction, the joints either side of it will tend to go in the opposite direction. ∘ It is thought to be a natural adaptation to achieve the maximum reach possible when one joint is persistently angulated. The Upper Limb 409 Investigation • Once diagnosis is established, serial CRP/ESR help monitor the disease. • X-rays that show these classic features indicate inadequate disease control: ∘ Joint space widening, seen initially as a result of effusion. ∘ Joint space narrowing and ankylosis, as a result of subsequent cartilage destruction. ∘ Juxta-articular erosions, resulting from the direct mechanical action of hypertrophied synovium. ∘ Fusiform soft tissue swelling. ∘ Generalised osteopenia. Non-operative treatment • Mainstay of treatment for RA. • Aims to induce remission with no active joint inflammation and no erosive or functional deterioration. • May require a combination of different drugs, classified as follows: Disease-modifying antirheumatic drugs (DMARDs) • First-line therapies; mechanisms of action are not fully understood. • They reduce joint swelling and pain, decrease acute-phase markers, limit progressive joint damage and improve function. • Examples include: ∘ Methotrexate ∘ Sulfasalazine ∘ Leflunomide (Arava® ) ∘ Hydroxychloroquine and chloroquine. • Gold and ciclosporin are limited by their toxicity. • DMARD side effects include hepatotoxicity, blood dyscrasias, interstitial lung disease. Biologic agents • TNF-α inhibitors ∘ Adalimumab (Humira® ) ∘ Etanercept (Enbrel® ) ∘ Golimumab (Simponi® ) ∘ Infliximab (Remicade® ) • IL-1 inhibitors ∘ Anakinra (Kineret® ) • IL-6 inhibitors ∘ Tocilizumab (RoActemra® ) • T-lymphocyte inhibitors ∘ Abatacept (Orencia® ) • B-lymphocyte inhibitors ∘ Belimumab (Benlysta® ). Glucocorticoids • Steroids have a relatively unfavourable risk/benefit profile. 410 Chapter 5 • Their two main indications in RA are: 1 Short-term control of flare-ups while DMARDs are adjusted. 2 Intra-articular injection for individual active joints. Symptom control • Analgesics control pain. • NSAIDs control pain and reduce stiffness. ∘ Given with a proton pump inhibitor to minimise GI side effects. Other supportive therapies • Exercise and physiotherapy • Psychological support • Control of comorbidities • Patient education. Operative treatment • Indications for surgery, in order of importance: 1 Relief of pain 2 Improvement of function 3 Prophylaxis to prevent further deformity 4 Cosmesis. • A contraindication to surgery is a pain-free hand with good function. ∘ Deformity without functional loss is not an indication for surgery. • Surgical options for most problems include: ∘ Synovectomy ∘ Arthroplasty ∘ Tendon repair, replacement or repositioning ∘ Arthrodesis. • Arthrodesis of hand joints is easily achieved in RA. ∘ Immobilising a joint with a transarticular K wire or screw, without excision of the joint, usually brings about fusion. • RA requires a staged surgical campaign based on these principles: ∘ Start proximal with shoulder and elbow. ∘ Do not forget the lower limb. – Patients may use crutches, which would affect upper limb rehabilitation. ∘ Be aware of when not to operate. ∘ Pick winning operations. • Willie Souter, orthopaedic surgeon based in Edinburgh from 1968 to 1997, presented a distillation of his career experience in the form of a league table of rheumatoid surgery winners and losers. ∘ Fusions, extensor synovectomy, Darrach’s procedure and MCPJ arthroplasty tend to be most successful. ∘ Flexor synovectomy, PIPJ and MCPJ synovectomy tend to be less successful. ∘ PIPJ arthroplasty and soft tissue procedures for swan neck and boutonnière tend to be least successful. The Upper Limb 411 The wrist • The classic wrist deformity is caput ulnae syndrome: ∘ Volar subluxation of the carpus from the ulna. ∘ Volar subluxation of the ECU. ∘ Supination of the carpus. • Findings on examination: ∘ Prominent ulnar head, which depresses then lifts on pressure (piano key sign). ∘ Dorsal swelling due to synovial proliferation of the wrist joint and extensor compartments. • Left untreated, progressive ulnar translocation of the carpus brings the extensor tendons over the rough surface of the prominent eroded ulnar head, causing attrition ruptures. • Surgical options: ∘ ECRL to ECU transfer to correct radial deviation and carpal supination. ∘ Excision arthroplasty of the distal ulna – Darrach’s procedure. – A sling of extensor retinaculum can be used to support the subluxed ECU tendon. • An alternative to Darrach’s procedure advocated for young patients is the Sauvé–Kapandji procedure. ∘ Involves DRUJ fusion with segmental resection of the distal ulna to allow forearm rotation. • A destroyed, painful wrist is successfully treated by arthrodesis. • Fusion using a Stanley pin inserted through the head of the 3rd metacarpal is straightforward. ∘ However, it fuses the wrist in a neutral position, potentially weakening grip. ∘ It also makes future MCPJ arthroplasty difficult. ∘ Some therefore advocate intermetacarpal placement of the pin. • An alternative for patients with adequate bone stock is fusion using a dorsal wrist plate. ∘ Newer locking plates give good fixation even in osteopenic bone. • Ulnar head replacement and total wrist arthroplasty are available but lack long-term data in RA. Dorsal tenosynovitis • Proliferative synovitis within the extensor compartments of the wrist presents as boggy swelling that extends proximally and distally. • Extensor tendon rupture may occur due to: ∘ Synovial infiltration of the tendons. ∘ Abrasion of EPL on Lister’s tubercle. ∘ Tendon attrition as they pass over a prominent, roughened ulnar head and DRUJ. • Extensor tenosynovectomy is indicated for swelling unresponsive to medical treatment. • The wrist is usually approached through a dorsal longitudinal midline incision. ∘ Gives excellent access and allows for other wrist operations that may be required in future. • On completion of synovectomy, part or all of the extensor retinaculum may be placed under, rather than over, the tendons. ∘ Provides a smooth surface for tendon glide. ∘ Protects tendons from future synovial infiltration. 412 Chapter 5 Extensor tendon rupture • Ruptures tend to occur from ulnar to radial. ∘ The ECU is usually displaced volarly out of harm’s way, making EDM first to rupture. – The patient loses independent pointing of the little finger. • Left untreated, progressive ruptures of each EDC tendon occurs as they are sawn through by the prominent, sharpened ulnar head. ∘ This process is termed Vaughan–Jackson syndrome. ∘ The spike of bone on the ulnar head is a Vaughan–Jackson lesion. • Primary repair is usually impossible because the tendon edges are frayed. ∘ Transfer of the little finger extensor to the intact ring finger extensor is straightforward. • However, as more extensors rupture, reconstruction becomes more difficult. • Ruptures of both little and ring extensors can be reconstructed by: ∘ Distal ends of both transferred to middle finger extensor, or ∘ Ring extensor transferred to middle extensor, and EI transfer to little. • Three finger ruptures can be reconstructed by: ∘ Middle finger extensor transferred to index EDC. ∘ EI or FDS middle transferred to ring and little finger extensors. • If all the tendons are ruptured, FDS middle can motor index and middle finger extensors, and FDS ring used for ring and little fingers. ∘ FDS is routed around the radial side of the wrist onto the dorsum of the hand. • Extensor reconstruction is often combined with Darrach’s procedure and extensor tenosynovectomy. • The MCPJs should also be assessed and treated as required. Differential diagnosis • Differential diagnosis of ‘drop finger’ in RA is popular with examiners: 1 Extensor tendon rupture – Loss of tenodesis effect on passive movement of the wrist. 2 Ulnar subluxation of the extensor tendon over the MCPJs – Due to attrition of the radial sagittal band. – Displacement of extensor tendons volar to the MCPJ axis makes initiation of extension impossible. – However, if the joint is passively extended, the patient will be able to maintain extension. 3 MCPJ dislocation – Not usually passively correctable. 4 PIN compression – Compressed by rheumatoid synovitis at the radiohumeral joint. – Loss of finger and thumb extension but preserved tenodesis. Flexor tenosynovitis • Typically, flexor tenosynovitis of the wrist presents with: ∘ Swelling proximal to the wrist crease ∘ Pain on finger flexion The Upper Limb 413 ∘ ∘ ∘ • • • • • Decreased range of active and passive finger movement Triggering Carpal tunnel syndrome. Flexor synovitis of the fingers can also present with tendon nodules. Crepitus is palpable on finger flexion. Synovial invasion of flexor tendons may lead to rupture. Treatment is by flexor synovectomy and removal of any bony spicules. Small nodules (rice bodies) may be found within the flexor sheath. Flexor tendon rupture • The FPL is the most commonly ruptured flexor tendon. • Usually occurs due to attrition from osteophytes on the scaphoid (Mannerfelt lesion). • Reconstruction is performed by one of these techniques: ∘ Direct repair (not usually possible) ∘ Tendon graft ∘ Middle or ring finger FDS transfer. • If the IPJ is unstable or destroyed, arthrodesis is a better option. • Rupture of other flexor tendons are treated as follows: ∘ FDP rupture in the palm – Transfer of the distal tendon stump to an adjacent FDP. ∘ FDP rupture in the finger – DIPJ arthrodesis with tenosynovectomy to preserve FDS. ∘ FDS – Rupture is not always recognised as there is little functional impairment. – Synovectomy may be done to protect FDP. ∘ FDP and FDS rupture – FDP reconstruction is prioritised. – The ruptured FDS can be used as a tendon graft. Metacarpophalangeal joints • MCPJ synovitis erodes through joint capsule dorsally – its weakest point. ∘ Stretches sagittal bands (thinnest radially) causing ulnar deviation of extensor tendons. • MCPJs eventually undergo volar subluxation and ulnar drift. • Factors responsible for volar subluxation: ∘ Weak or stretched dorsal extensor expansion. ∘ Displacement of extensor tendons into the intermetacarpal valleys, where they act as flexors. ∘ Synovitis that stretches collateral ligaments and volar plate. ∘ Intrinsic tightness. ∘ Erosion of the metacarpal head. • Ulnar drift has two components: 1 Ulnar deviation: pathological when uncorrectable. 2 Ulnar shift: translation of the phalanx on the metacarpal head, causing joint incongruity and eventual subluxation. 414 Chapter 5 • Factors responsible for ulnar drift of the fingers include: ∘ Thumb pressure on the index finger from key pinch. ∘ Intrinsic tightness. ∘ Pull of ADM. ∘ Ulnar inclination of the metacarpal heads. ∘ Radial deviation of the wrist, causing compensatory ulnar deviation of MCPJs by the Z mechanism. ∘ Ulnar deviating forces of the flexor tendons, which enter the hand on the ulnar side of the wrist. • Surgical options for MCPJ disease include: ∘ Synovectomy alone. ∘ Synovectomy combined with soft tissue rebalancing, including: – Intrinsic release. – Crossed intrinsic transfer. • Involves releasing the ulnar intrinsics of index, middle and ring fingers and transferring them to the radial side of adjacent fingers. – Extensor tendon stabilisation. ∘ Arthroplasty with Swanson-type silicone elastomer implants. Proximal interphalangeal joints • PIPJ synovitis follows the path of least resistance dorsally, stretching the extensor mechanism. • The resulting imbalance produces either a swan neck or boutonnière deformity. Swan neck deformity • Characterised by PIPJ hyperextension with MCPJ and DIPJ flexion (Z mechanism). • The exact cause of deformity is unclear; contributory factors include: ∘ PIPJ volar plate rupture. ∘ Attenuation of FDS by synovitis. ∘ Intrinsic tightness. ∘ MCPJ subluxation. Classification • Nalebuff’s classification helps guide treatment. • Type I: PIPJ flexible. ∘ Treated with silver ring splints to prevent PIPJ hyperextension. ∘ Flexor tenodesis (sublimis sling) achieves the same by using a slip of FDS: – This is detached proximally and anchored to hold the PIPJ in some flexion. • Type II: PIPJ limited in certain MCPJ positions (intrinsic tightness). ∘ Treated by intrinsic release. • Type III: PIPJ fixed in hyperextension. ∘ Requires gentle manipulation under anaesthesia and intrinsic release. • Type IV: as for type III but with joint changes on X-ray. ∘ Requires arthrodesis or arthroplasty. The Upper Limb 415 Boutonnière deformity • Boutonnière means ‘buttonhole’ in French, which resembles the lateral bands as the PIPJ pokes up between them in this deformity. • Characterised by PIPJ flexion with MCPJ and DIPJ extension (Z mechanism). • Synovitis leads to disruption of the weakest part of the extensor mechanism. ∘ This lies just lateral to the central slip over the PIPJ. ∘ Results in volar displacement of the lateral bands, under the influence of the transverse retinacular ligaments. ∘ The lateral bands then exert a flexor force on the PIPJ. ∘ Eventually, attrition of the central slip occurs. Classification • Nalebuff and Millender’s classification helps guide treatment. • Type I: PIPJ extensor lag of 10∘ –15∘ , passively correctable. ∘ Night splinting with steroid injection. ∘ Dolphin or Fowler tenotomy. – These tenotomies divide the lateral bands distal to the PIPJ. – This reduces the abnormal flexion force exerted by them on the PIPJ. – Tenotomy is done proximal to the oblique retinacular ligament insertion, which avoids a mallet deformity. • Type II: PIPJ extensor lag of 30∘ –40∘ , passively correctable. ∘ Surgery to shorten the central slip or centralise the lateral bands. • Type III: Fixed flexion deformity of the PIPJ. ∘ Arthrodesis or, rarely, Swanson-type arthroplasty. The thumb • Z deformity of the thumb occurs due to either boutonnière or swan neck deformity. • Mechanisms underlying these deformities are analogous to those in the finger: ∘ Thumb MCPJ ≅ finger PIPJ. ∘ Thumb IPJ ≅ finger DIPJ. ∘ Adductor pollicis and APB ≅ intrinsic lateral bands. ∘ EPB ≅ central slip. Classification • Nalebuff’s classification describes rheumatoid thumb deformities: ∘ Type I: Boutonnière (most common). ∘ Type II: Mixed type I and type III – adducted boutonnière (rare). ∘ Type III: Swan neck. ∘ Type IV: Gamekeeper’s thumb – laxity of MCPJ UCL. ∘ Type V: Swan neck without CMCJ adduction contracture. Treatment • Treatment is aimed at the seat of disease: ∘ Types I, IV and V represent predominant MCPJ disease. – The thumb MCPJ is successfully treated by arthrodesis. 416 ∘ Chapter 5 Type III is predominantly CMCJ disease. – Can be treated by trapeziectomy. – A hemiarthroplasty is available that resembles half a Swanson-type implant. Psoriatic arthropathy • Usually a seronegative oligoarthritis found in patients with psoriasis. ∘ 10% with the skin disease develop inflammatory arthritis. • Develops between age 35 and 55; no sex predilection. • Clinically characterised by: ∘ RF negative. ∘ Involvement of DIPJs (10%). ∘ Acute attacks affecting the entire finger – dactylitis or sausage finger (35%). ∘ Arthritis mutilans (<5%). – Results from osteolysis and dissolution of joints. – The resultant telescoping of the bones leaves redundant folds of skin – so-called opera glass hand or la main en lorgnette. • Characteristic nail changes affect 80% with arthropathy but only 20% with uncomplicated psoriasis: ∘ Uniform nail pitting. ∘ Leukonychia. ∘ Onycholysis. ∘ Subungual hyperkeratosis. • Radiological features: ∘ Asymmetric joint surface erosions. ∘ Erosion of the distal phalanx tuft (acro-osteolysis). ∘ ‘Pencil-in-cup’ deformity: – Concave ‘cup’ deformity of the distal phalanx articular surface. – Convex ‘pencil’ deformity of the middle phalanx. • Diagnosis is based on clinical and radiological findings. • Medical treatment with DMARDs, NSAIDs, biologic agents and intra-articular steroid injection forms the mainstay of treatment. • Surgery may be indicated for salvage: ∘ Arthrodesis ∘ Arthroplasty ∘ Bone grafts to lengthen digits in arthritis mutilans. Systemic lupus erythematosus (SLE) • Systemic autoimmune disorder. ∘ Produces hand deformities similar to those of RA. • In contrast to RA, there is no erosive arthritis. ∘ Deformities arise largely due to ligamentous laxity. • Pain is typically disproportionate to the degree of swelling. • Annual UK incidence 5 per 100,000 population. • Mean age of onset is 15–25 years; female to male ratio 9:1. The Upper Limb 417 • Raynaud’s phenomenon is common in SLE. • Medical treatments include NSAIDs, antimalarials, immunosuppressants, biologic agents and corticosteroids. • Soft tissue laxity makes soft tissue reconstructions short-lived, leading to recurrence. • For this reason, surgical intervention usually involves arthrodesis rather than arthroplasty. Gout • Inflammatory arthritis characterised by self-limiting, excruciatingly painful acute attacks. • Males affected four times more commonly than females. • Caused by intra- and periarticular deposition of needle-shaped monosodium urate (MSU) crystals. ∘ Urate crystals initiate an inflammatory arthritis. • Recurrent attacks cause cumulative joint damage, instability and tendon ruptures. • MSU is derived from uric acid – hyperuricaemia is a risk factor for gout. ∘ Not all with hyperuricaemia develop gout. ∘ Attacks can occur with normal uric acid levels. • Hyperuricaemia may be primary or secondary. • Causes of primary hyperuricaemia include: ∘ Decreased renal clearance of uric acid ∘ Rare inborn errors of metabolism. • Secondary hyperuricaemia is caused by: ∘ Diuretics (particularly thiazides) ∘ Myeloproliferative disorders ∘ Cytotoxic drugs ∘ Alcohol. ∘ Excessive dietary purine intake and diets high in fructose. • Years of untreated gout can lead to chronic tophaceous gout. ∘ Tophi are subcutaneous nodules of uric acid crystals that commonly form in the hands. • Most gout is treated in primary care or by rheumatologists. • Surgery is occasionally indicated for unstable joints or symptomatic tophi. • Pseudogout is caused by deposits of calcium pyrophosphate. ∘ Unlike gout, there are no specific drugs that treat the underlying cause. Miscellaneous tendinopathy • These are mistakenly classified as inflammatory conditions, e.g. tenosynovitis. ∘ Neither trigger finger nor de Quervain’s disease are associated with inflammatory cells at the site of pathology. Trigger finger • Describes a popping or snapping as a digit is put through its range of motion. ∘ Can be associated with pain and locking. • A common condition; predominantly affects middle-aged females. • The thumb is most frequently affected, followed by the ring finger. 418 Chapter 5 Pathogenesis • Impingement of flexor tendons as they pass through a narrowed A1 pulley. • Repetitive loading causes thickening within the tendon and flexor sheath. • May be related to degenerative change around the metacarpal head, leading to narrowing of the fibro-osseous canal. • Secondary triggering is seen in rheumatic diseases. Treatment • Most respond well to one or two steroid injections into the flexor sheath. ∘ Rupture of the tendon or flexor sheath is a rare side effect. • Failure to respond to steroids requires A1 pulley release. • A1 pulley release in rheumatoid can exacerbate ulnar drift. ∘ Excision of FDS may be preferred for these patients. De Quervain’s disease • Stenosis of the first extensor compartment, which contains EPB and APL tendons. • Middle-aged women and post-partum lactating mothers are most frequently affected. Pathogenesis • Thought to be caused by repeated thumb abduction with an ulnar-deviated wrist. • Friction at the opening of the retinacular sheath leads to swelling and narrowing of the fibro-osseous canal. Diagnosis • Based on a history of radial wrist pain exacerbated by thumb movements. • There may be a tender swelling just proximal to the radial styloid. • Finkelstein’s test is a provocative test where the thumb is pulled into ulnar deviation under longitudinal traction. ∘ Affected patients anticipate severe pain and begin to get out of their chair as the thumb is moved. Treatment Non-operative • Splint immobilisation ∘ Effective while the splint is in situ; symptoms recur shortly after removal. • Steroid injection ∘ Leads to resolution in up to 80% of cases after two injections. Operative • Surgical release of the first extensor compartment is indicated when steroid injections have failed. The Upper Limb 419 • The anatomy of this compartment is variable: ∘ There may be multiple separate sheaths and septations ∘ There may be multiple slips of APL and EPB. • All these must be released to ensure successful decompression. • Branches of the superficial radial nerve are at risk during the approach. Further reading Congenital deformities Buck-Gramcko D. Pollicization of the index finger. Method and results in aplasia and hypoplasia of the thumb. J Bone Joint Surg Am 1971;53(8):1605–17. Buck-Gramcko D. Radialization as a new treatment for radial club hand. J Hand Surg Am 1985;10(6 Pt 2): 964–8. Hough M, Fenn C, Kay SP. The use of free groin flaps in children. Plast Reconstr Surg 2004;113(4):1161–6. de Jong JP, Moran SL, Vilkki SK. Changing paradigms in the treatment of radial club hand: microvascular joint transfer for correction of radial deviation and preservation of long-term growth. Clin Orthop Surg 2012;4(1):36–44. Kallemeier PM, Manske PR, Davis B et al. An assessment of the relationship between congenital transverse deficiency of the forearm and symbrachydactyly. J Hand Surg Am 2007;32(9):1408–12. Swanson AB. A classification for congenital limb malformations. J Hand Surg Am 1976;1(1):8–22. Hand trauma Abrahamian FM, Goldstein EJ. Microbiology of animal bite wound infections. Clin Microbiol Rev 2011; 24(2):231–46. Bansal R, Craigen MA. Fifth metacarpal neck fractures: is follow-up required? J Hand Surg Eur Vol 2007; 32(1):69–73. Ellis CV, Kulber DA. Acellular dermal matrices in hand reconstruction. Plast Reconstr Surg 2012;130 (5 Suppl 2):256S–69S. Evans DM, Martin DL. Step-advancement island flap for fingertip reconstruction. Br J Plast Surg 1988; 41(2):105–11. Giessler GA, Erdmann D, Germann G. Soft tissue coverage in devastating hand injuries. Hand Clin 2003; 19(1):63–71. Hattori Y, Doi K, Sakamoto S et al. Fingertip replantation. J Hand Surg Am 2007;32(4):548–55. Hynes MC, Giddins GE. Dynamic external fixation for pilon fractures of the interphalangeal joints. J Hand Surg Br 2001;26(2):122–4. James R, Kesturu G, Balian G et al. Tendon: biology, biomechanics, repair, growth factors, and evolving treatment options. J Hand Surg Am 2008;33(1):102–12. Lin CH, Lin CH, Lin YT et al. The medial sural artery perforator flap: a versatile donor site for hand reconstruction. J Trauma 2011;70(3):736–43. Moiemen NS, Elliot D. Composite graft replacement of digital tips. 2. A study in children. J Hand Surg Br 1997;22(3):346–52. 420 Chapter 5 Quaba AA, Davison PM. The distally-based dorsal hand flap. Br J Plast Surg 1990;43(1):28–39. Schreuders TA. The quadriga phenomenon: a review and clinical relevance. J Hand Surg Eur Vol 2012;37(6):513–22. Sebastin SJ, Ho A, Karjalainen T et al. History and evolution of the Kessler repair. J Hand Surg Am 2013;38(3):552–61. Small JO, Brennen MD, Colville J. Early active mobilisation following flexor tendon repair in zone 2. J Hand Surg Br 1989;14(4):383–91. Sylaidis P, Youatt M, Logan A. Early active mobilization for extensor tendon injuries. The Norwich regime. J Hand Surg Br 1997;22(5):594–6. Wei FC, el-Gammal TA, Lin CH et al. Metacarpal hand: classification and guidelines for microsurgical reconstruction with toe transfers. Plast Reconstr Surg 1997;99(1):122–8. Complex regional pain syndrome Turner-Stokes L, Goebel A. Guideline Development Group. Complex regional pain syndrome in adults: concise guidance. Clin Med 2011;11(6):596–600. Nerve compression Lanz U. Anatomical variations of the median nerve in the carpal tunnel. J Hand Surg Am 1977;2(1):44–53. Vella JC, Hartigan BJ, Stern PJ. Kaplan’s cardinal line. J Hand Surg Am 2006;31(6):912–8. Brachial plexus Borschel GH, Clarke HM. Obstetrical brachial plexus palsy. Plast Reconstr Surg 2009;124(1 Suppl):144e–155e. Chuang DC. Brachial plexus reconstruction based on the new definition of level of injury. Injury 2008;39 Suppl 3:S23–9. Doi K. Management of total paralysis of the brachial plexus by the double free-muscle transfer technique. J Hand Surg Eur Vol 2008;33(3):240–51. Kay SP. Obstetrical brachial palsy. Br J Plast Surg 1998;51(1):43–50. Mackinnon SE, Novak CB, Myckatyn TM et al. Results of reinnervation of the biceps and brachialis muscles with a double fascicular transfer for elbow flexion. J Hand Surg Am 2005;30(5):978–85. Teboul F, Kakkar R, Ameur N et al. Transfer of fascicles from the ulnar nerve to the nerve to the biceps in the treatment of upper brachial plexus palsy. J Bone Joint Surg Am 2004;86-A(7):1485–90. Dupuytren’s disease Black EM, Blazar PE. Dupuytren disease: an evolving understanding of an age-old disease. J Am Acad Orthop Surg 2011;19(12):746–57. Dias JJ, Braybrooke J. Dupuytren’s contracture: an audit of the outcomes of surgery. J Hand Surg Br 2006;31(5):514–21. Hindocha S, Stanley JK, Watson S et al. Dupuytren’s diathesis revisited: Evaluation of prognostic indicators for risk of disease recurrence. J Hand Surg Am 2006;31(10):1626–34. The Upper Limb 421 Tumours Dias J, Buch K. Palmar wrist ganglion: does intervention improve outcome? A prospective study of the natural history and patient-reported treatment outcomes. J Hand Surg Br 2003;28(2):172–6. Dias JJ, Dhukaram V, Kumar P. The natural history of untreated dorsal wrist ganglia and patient reported outcome 6 years after intervention. J Hand Surg Eur Vol 2007;32(5):502–8. Arthritis National Collaborating Centre for Chronic Conditions. Osteoarthritis: National Clinical Guideline for Care and Management in Adults. London: Royal College of Physicians, 2008. National Collaborating Centre for Chronic Conditions. Rheumatoid Arthritis: National Clinical Guideline for Management and Treatment in Adults. London: Royal College of Physicians, February 2009. Scott DL, Wolfe F, Huizinga TW. Rheumatoid arthritis. Lancet 2010;376(9746):1094–108. Stack HG. Button hole deformity. Hand 1971;3(2):152–4. CHAPTER 6 The Lower Limb CHAPTER CONTENTS Leg ulcers, 422 Lower limb trauma, 426 Osteomyelitis, 438 Lymphoedema, 441 Pressure ulcers, 451 Further reading, 457 Leg ulcers • Most common chronic wounds in developed countries. • Affect 1–3% of the British population. Aetiology • Leg ulceration may be caused by ‘VATIMAN’: ∘ Venous disease ∘ Arterial disease ∘ Trauma – Insect bites – Trophic ulcers – Self-inflicted injuries – Burns and frostbite – Radiation ∘ Infection – Bacterial – Fungal – Mycobacterial – Syphilis ∘ Metabolic disorders – Diabetes – Necrobiosis lipoidica diabeticorum – Pyoderma gangrenosum – Porphyria – Gout – Calciphylaxis Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 422 The Lower Limb ∘ ∘ 423 Autoimmune diseases – Vasculitis – Systemic lupus erythematosus (SLE) – Systemic sclerosis (scleroderma) – Rheumatoid arthritis – Polyarteritis nodosa Neoplasia – Squamous cell carcinoma (SCC) – Marjolin ulcer – Basal cell carcinoma (BCC) – Melanoma – Kaposi sarcoma – Lymphoma. The leg ulcer patient Medical history • • • • • • Time and mechanism by which the ulcer started Previous treatment Ambulatory status Type of footwear Symptoms suggestive of a cause, e.g. claudication, rest pain Relevant comorbidities, e.g. diabetes, smoking. Examination 1 The ulcer itself ∘ Examined for features suggestive of aetiology: – Venous ulcers – classically in the gaiter area, sloping edges. – Arterial ulcers – usually on toes, feet or ankles, ‘punched out’ edges. – Features of malignancy. 2 State of the circulation ∘ Temperature, capillary refill. ∘ Peripheral pulses. ∘ Varicose veins, oedema, venous eczema, hyperpigmentation – all suggest underlying venous disease. 3 Sensation ∘ ‘Glove and stocking’ sensory loss suggests peripheral neuropathy. Investigation • Microbiology wound swab • Ankle brachial pressure index (ABPI) • Vascular studies • Radiology ∘ X-rays, CT and bone scans assess bony involvement. • Biopsy of long-standing ulcers to exclude malignancy • Onward referral to a rheumatologist for vasculitis or connective tissue disorder. 424 Chapter 6 Venous ulcer disease • An area of epidermal discontinuity that persists for four weeks or more, occurring as a result of venous hypertension and insufficiency of the calf muscle pump. • Accounts for 80% of lower limb ulceration. • Venous hypertension may be caused by: ∘ Reflux of venous blood due to valvular incompetence ∘ Venous obstruction ∘ Insufficiency of the calf muscle pump. • May affect the superficial system (long and short saphenous veins), deep system or interconnecting perforators. • Valvular incompetence occurs due to thrombophlebitis, previous thrombosis or trauma. • Pathogenesis is not fully understood; mooted mechanisms include: 1 Venous hypertension causes protein-rich exudate to leak into subcutaneous tissue. – Forms a pericapillary fibrin cuff, causing local tissue hypoxia. 2 Venous hypertension causes extravasation of erythrocytes. – Triggers an inflammatory response, with deposition of haemosiderin within macrophages. – Transforming growth factor (TGF)-β may mediate dermal fibrosis, lipodermatosclerosis and eventual ulceration. – Lipodermatosclerosis is characterised by: • Scarring • Fibrotic, hyperpigmented skin • ‘Inverted champagne bottle’ appearance. Management Non-operative 1 Bed rest and leg elevation ∘ Impractical for most patients; ulceration tends to recur with ambulation. 2 Compression ∘ Gold standard treatment; used continuously until healing occurs. – Mean time to healing is 5 months. – Ulcer recurrence rate 30% in 5 years. ∘ Four-layer bandaging enables the shortest time to healing. – The four layers are applied from toes to knee and consist of: • Orthopaedic wool • Crêpe bandage • Elastic bandage • Cohesive retaining layer. ∘ Compression stockings are easier to use; there is limited evidence of their superiority over bandaging. – Stockings are classified as: • Class 1 (light): 14–17 mmHg The Lower Limb • Class 2 (medium): 18–24 mmHg • Class 3 (strong): 25–35 mmHg. 3 Local treatments 4 Pentoxifylline (unlicensed indication). Operative • Venous ulceration is not usually managed surgically. • Indications for surgery may include: ∘ Intractable pain ∘ Failure of non-operative treatment ∘ Surgically treatable venous disease. • Surgery addresses both the underlying venous disease and the ulcer. Treatment of venous disease • Ablation of superficial and perforating veins. ∘ Achieved by open surgery or endovenous laser ablation. • Subfascial endoscopic perforating vein surgery (SEPS). • Reconstruction of the deep venous system. Treatment of the venous ulcer • Debridement and skin grafting. ∘ High recurrence rate if underlying venous pathology is not corrected. • Excision with flap reconstruction. ∘ In exceptional circumstances, pedicled or free flaps are used after ulcer excision. Arterial ulcer disease • Results from reduced blood supply to the lower limb. • Most common cause is atherosclerosis, risk factors for which include: ∘ Age ∘ Family history ∘ Smoking ∘ Diabetes ∘ Hypertension ∘ Hyperlipidaemia ∘ Obesity. • Generalised changes in the limb: ∘ Dusky erythema ∘ Lower surface temperature ∘ Lack of hair growth ∘ Thin, brittle, atrophic skin ∘ Thickened or missing toenails ∘ Absent peripheral pulses. 425 426 Chapter 6 • Ulceration may develop after seemingly trivial trauma. ∘ Patients should be taught how to care for their skin. Management • Combination of operative and non-operative methods. • Debridement or negative pressure wound therapy may enlarge the area of ischaemia. Non-operative management • Control of modifiable risk factors, e.g. diabetes, smoking • Graded exercise regime • Foot care • Infection prevention • Cilostazol or pentoxifylline. Operative management • Indications for invasive treatment: ∘ Non-healing ulceration ∘ Gangrene ∘ Rest pain ∘ Progression of disabling claudication. • Aim to improve blood flow into the affected limb. ∘ This accelerates healing time. ∘ Achieved by reconstructive vascular surgery or angioplasty. Lower limb trauma Epidemiology • Annual incidence of open lower limb fractures is approximately 5 per 100,000 population. • Analysis of open tibial fractures treated by the Edinburgh Orthopaedic Trauma Unit (1988–1990) revealed: ∘ 21% Gustilo type I injuries. ∘ 19% Gustilo type II. ∘ 60% Gustilo type III. – Of type III fractures: 27% type IIIA, 60% type IIIB, 8% type IIIC. • Average age 42 years. • Most common mechanisms of injury: ∘ Fall from height ∘ Motor vehicle collision ∘ Interpersonal violence. Classification of open fractures • Numerous classifications have been described: ∘ Gustilo and Anderson (1976) The Lower Limb ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ 427 Hannover Fracture Scale-97 (HFS-97) (1982) Byrd and Spicer (1985) Predictive salvage index (PSI) (1987) Mangled Extremity Severity Score (MESS) (1990) The AO soft tissue grading system (1991) Limb salvage index (LSI) (1991) Nerve injury, ischemia, soft tissue, skeletal, shock and age of patient (NISSSA) (1994) Ganga hospital score (2006) Bastion classification (2012). Gustilo and Anderson • Widely used; relatively simple to apply. • Based on a retrospective study of long bone fractures. • Open fractures are best classified after wound excision. • Poor inter-observer reliability. • No account is taken of fracture characteristics or nerve/muscle injury. ∘ Grade IIIB is therefore a diverse group. • Open fractures were originally classified into three categories: Type I • Open fracture with a wound <1 cm long and clean. Type II • Open fracture with a laceration >1 cm long without extensive soft tissue damage, flaps or avulsions. Type III • Either open segmental fracture, open fracture with extensive soft tissue damage or traumatic amputation. ∘ This key point is often overlooked: all high energy pattern injuries are Type III. • Special categories in Type III: ∘ Gunshot injuries ∘ Any open fracture caused by a farm injury ∘ Any open fracture with accompanying vascular injury requiring repair. • In 1984, Gustilo et al. subclassified type III injuries: Type IIIA • Adequate soft tissue coverage of a fractured bone despite extensive soft tissue laceration or flaps. • High energy trauma irrespective of the size of the wound. Type IIIB • Extensive soft tissue injury with periosteal stripping and bony exposure. ∘ This is usually associated with massive contamination. 428 Chapter 6 Type IIIC • Open fracture associated with arterial injury requiring repair. MESS • Designed to predict whether a lower limb is salvageable. • Total score ≤6 is consistent with a salvageable limb, using modern multidisciplinary surgical reconstruction techniques. • May aid decision making when primary amputation is considered. • Does not replace experienced clinical judgement. A. Skeletal/soft tissue injury • Low energy (stab, simple fracture, civilian gunshot wound): 1 • Medium energy (open or multiple fractures, dislocation): 2 • High energy (close-range shotgun, military gunshot wound, crush injury): 3 • Very high energy (above + gross contamination, soft tissue avulsion): 4 B. Limb ischaemia (double the score for ischaemia >6 h) • Pulse reduced or absent but perfusion normal: 1 • Pulseless, paraesthesias, diminished capillary refill: 2 • Cool, paralysed, insensate, numb: 3 C. Shock • Systolic blood pressure always >90 mmHg: 0 • Hypotensive transiently: 1 • Persistent hypotension: 2 D. Age (years) • <30: 0 • 30–50 years of age: 1 • >50 years of age: 2. NISSSA • Aims to address MESS’s shortcomings by including nerve injury, and more detailed information about muscle and soft tissue injuries. • Applies only to open tibial fractures. • More sensitive and specific than MESS. AO system • The most comprehensive soft tissue classification. • However, it is very complex; usually reserved for research or coding. Bastion classification • Named after Camp Bastion, the main British military base in Afghanistan. • Classifies lower limb injuries caused by improvised explosive devices. The Lower Limb 429 Initial management of lower limb trauma • As with all trauma, initial assessment is an ATLS-style primary survey. • The purpose of the primary survey is to identify and treat all immediately life-threatening problems. • The <C>ABC approach, adopted by the military, may be appropriate. ∘ This attends to <C>, catastrophic haemorrhage, early on in the algorithm. ∘ A tourniquet may be required to stop bleeding. History • Mechanism of injury is a guide to the level of energy transferred. • Factors suggestive of high energy injury: ∘ High speed motor vehicle accidents, particularly pedestrian. ∘ Falls from significant height ∘ Missile wounds ∘ Any injury involving crushing. Examination • Establish the neurovascular status: ∘ Capillary refill time. ∘ Dorsalis pedis and posterior tibial arterial pulse. ∘ Active movement of toes and ankle (common peroneal and tibial nerves). ∘ Sensation on the sole of foot (tibial nerve) and first webspace (deep peroneal nerve). ∘ Re-examine neurovascular status regularly, particularly after fracture manipulation. • Factors suggestive of high energy injury: ∘ Transverse or segmental fracture pattern with comminution ∘ Associated injuries ∘ Large soft tissue defect ∘ Closed degloving, where skin is intact but perforating vessels are divided. ∘ Tyre prints. Treatment • Current UK Standards recommend this initial treatment: 1 Analgesia. 2 Restore limb alignment; splint using plaster of Paris backslab. 3 Remove gross contamination. 4 Photograph the wound. 5 Cover the wound with sterile, saline-moistened gauze covered with semi-occlusive film dressing. 6 Repeat neurovascular examination. 7 Intravenous antibiotics – co-amoxiclav or cefuroxime 8 hourly: – Continue until definitive soft tissue cover or 72 hours, whichever is sooner. – Additional ‘single shot’ gentamicin 1.5 mg/kg at the time of debridement. – Additional ‘single shot’ gentamicin and either teicoplanin or vancomycin at the time of skeletal stabilisation and definitive soft tissue closure. – Penicillin allergy: give clindamycin instead of coamoxiclav/cefuroxime. 430 Chapter 6 8 Tetanus prophylaxis if required. 9 X-ray – two views, including the joints above and below the fracture. Surgical management • Summarised as: ∘ Debridement ∘ Skeletal stabilisation ∘ Soft tissue cover. Timing • The traditional ‘6-hour rule’ of open fracture surgery was based on the doubling time of Staphylococcus. ∘ This is the time it takes one bacterium to reach an infective load of 105 organisms. • However, many studies fail to demonstrate a relationship between the timing of debridement and outcome. • UK Standards recommend primary surgery within 24 hours of injury by senior plastic and orthopaedic surgeons. • Exceptions mandating immediate surgery: 1 Gross contamination 2 Compartment syndrome 3 Devascularised limb 4 Another injury requiring immediate surgery. Primary surgery • A major aim of primary surgery is to convert a contaminated traumatic wound into a clean surgical wound. • This is achieved by three ‘Es’: 1 Extend 2 Explore 3 Excise. • Use of a thigh tourniquet is preferred by some surgeons. Wound extension • Extend along lines of election for fasciotomy to assess the entire zone of trauma. ∘ Should not injure perforators that supply local fasciocutaneous flaps. Degloving injuries • Degloving is avulsion of skin and subcutaneous tissue from underlying muscle or bone. • Degloving is classified by Arnež: ∘ Pattern 1 – Limited degloving with abrasion/avulsion – Tissue loss due to abrasion/avulsion and limited degloving of remaining skin. – Typically occurs around bony prominences; may expose bone or joint. The Lower Limb 431 ∘ Pattern 2 – Non-circumferential degloving – Most skin remains as a flap or undermined area, usually just superficial to muscle fascia. ∘ Pattern 3 – Circumferential single-plane degloving – More extensive than pattern 2; skin does not usually survive. ∘ Pattern 4 – Circumferential multiplane degloving – Similar to pattern 3, but with additional breach of muscle fascia. – Degloving can run between muscles and between muscle and periosteum. – Indicative of high energy transfer. • The margins of excision following degloving can be difficult to determine. • Findings suggestive of non-viable skin: ∘ Fixed staining and thrombosis of subcutaneous veins. ∘ Circumferential degloving. ∘ Poor perfusion, demonstrated by intravenous fluorescein and a Wood’s lamp. ∘ Newer technologies using indocyanine green (ICG) fluorescence have been reported. Muscle • Muscle viability is assessed by four Cs: 1 Colour (pink) 2 Contraction 3 Consistency (dead muscle tears easily in the jaws of forceps) 4 Capacity to bleed. Bone • Deliver the ends of the fracture out of the wound. ∘ This allows complete assessment and debridement of the wound and bone. ∘ The deep posterior compartment can be inspected this way. • Loose bone fragments that fail the ‘tug test’ are removed. ∘ Large articular fragments that can be fixed with absolute stability are preserved. • Bone viability is determined by its capacity to bleed: 1 Punctate bleeding from exposed cortical surfaces (paprika sign). 2 Extent of periosteal stripping and muscle/fascia connections. • Following excision, irrigate the wound with large volumes of warm saline. ∘ High pressure pulse lavage is not recommended – Associated with deep bacterial inoculation and tissue damage. • Second look within 24–48 hours is occasionally indicated; multiple serial debridements are associated with worse outcomes. Fracture stabilisation • Provisional stabilisation is achieved with a spanning external fixator. ∘ Indicated when definitive stabilisation and soft tissue cover cannot be achieved at primary surgery. ∘ Pins are inserted through ‘safe corridors’ to avoid neurovascular structures. 432 Chapter 6 ∘ ∘ The construct should allow access to the wound for soft tissue cover. If conversion to definitive internal fixation is planned, UK Standards recommend this occurs within 72 hours of primary surgery. • Definitive stabilisation is usually achieved by internal fixation (intramedullary nail, plate, screws). ∘ Internal fixation should not be placed if immediate soft tissue cover cannot be achieved. ∘ Orthopaedic implants within open wounds are associated with higher infection rate. Vascular injury • Limb devascularisation requires emergency surgical exploration. • Muscle suffers irreversible ischaemic damage in 3–4 hours. ∘ The maximum acceptable delay is 6 hours of warm ischaemia. • Diagnosed by absent dorsalis pedis or posterior tibial pulse on palpation or Doppler. ∘ Capillary refill in the toes can be misleading. • Preoperative angiography unnecessarily prolongs ischaemia time. ∘ The level of vascular injury is predicted by the fracture or dislocation. • Management of vascular injuries: 1 Direct exploration of the suspected site of injury. 2 Immediate revascularisation by temporary shunts, e.g. Javid, Pruitt-Inahara or Sundt. – Venous injury at, or proximal to, the popliteal vein is also shunted. – Risk of cardiovascular events as toxic metabolites enter the systemic circulation. – Renoprotective measures may prevent complications of myoglobinuria. 3 Once circulation is restored, reasses the limb. 4 If salvageable, stabilise the skeleton with an external fixator. 5 Replace shunts with reversed vein grafts. 6 Fasciotomy is required following revascularisation – muscle tends to swell postoperatively. – If not done, compartment pressure monitoring should be performed repeatedly. Wound cover • The decision to proceed with definitive soft tissue cover at primary surgery depends on: 1 Immediate definitive bony stabilisation possible? – Is the fracture configuration fully understood? • May require further imaging with CT. 2 Plastic surgeon available? 3 What flaps are available? 4 Zone of injury well defined? 5 Recipient vessels available? – May require CT angiography. 6 Patient stable enough to withstand long surgery? Temporary • Topical negative pressure dressing ∘ Should not be used instead of definitive vascularised soft tissue cover. ∘ Use for >7 days associated with increased risk of deep infection. The Lower Limb 433 • Antibiotic bead pouch ∘ Supplies higher local concentrations of antibiotics than systemic administration. ∘ Polymethylmethacrylate (PMMA) cement is impregnated with an antibiotic – usually gentamicin or tobramycin. ∘ PMMA beads are placed in the wound, then covered with a semi-occlusive film dressing. ∘ Antibiotic elutes from the cement; can remain effective for 21 days. Definitive • Definitive cover requires vascularised soft tissue. • UK Standards state this be done by senior specialist teams on a semi-elective basis within 7 days of injury. ∘ Evidence favours early closure to avoid infection. ∘ Delay >7 days increases likelihood of friable/fibrotic recipient vessels. Local or regional fasciocutaneous and muscle flaps • Reserved for low energy injuries with limited zone of trauma. • Fasciocutaneous flaps are typically raised on septocutaneous or myocutaneous vessels from peroneal or posterior tibial arteries. ∘ Can be located with hand-held Doppler to aid flap planning. • The pedicled medial sural artery perforator flap and reverse flow sural neurocutaneous flap can cover defects over the proximal and distal tibia, respectively. • Anterolateral thigh flap can be pedicled distally for proximal tibial wounds. • Common pedicled muscle flaps for lower leg coverage: ∘ Medial gastrocnemius for knee and proximal third. ∘ Medial hemisoleus for middle third. ∘ Bipedicled tibialis anterior for middle third. Free tissue transfer • Mainstay of treatment for high energy open tibial fractures. • Ongoing debate about fasciocutaneous versus muscle flap superiority. • There is little robust, high quality evidence to support use of one flap over another. • Proponents of fasciocutaneous flaps say: ∘ Aesthetically superior. ∘ Easier to re-elevate for secondary bony reconstruction. ∘ May be sensate. ∘ Minimal donor site morbidity. • Proponents of muscle flaps say: ∘ Conform better to cavities. ∘ Act as ‘muscle macrophages’, reducing likelihood of infection. ∘ Experimental data demonstrates improved bone healing. ∘ Muscle thins over time to provide a good aesthetic result. • Recipient vessels in the lower leg: ∘ Posterior tibial artery – Approached medially between flexor digitorum longus and soleus. • The neurovascular bundle is between soleus and tibialis posterior. 434 Chapter 6 – Also approachable posteriorly, known as the ‘Godina split’: • Posterior mid-calf incision deepened between the heads of gastrocnemius and through soleus. ∘ Anterior tibial artery – Approached just lateral to the subcutaneous border of the tibia. – The neurovascular bundle is on the interosseous membrane, between tibialis anterior and long toe extensors. • More proximal recipients include popliteal and superficial femoral vessels. ∘ Often requires interposition vein grafts. • Long and short saphenous veins provide additional drainage options if venae comitantes are unsuitable. • A ‘single vessel leg’ can support a free flap by anastomosing end-to-side. ∘ Reconstruction of the other injured vessels with vein grafts is considered. Management of segmental bone defects Primary bone shortening • Can be done for segmental defects <5 cm. • Acute shortening >5 cm may cause circumferential full thickness necrosis of a doughnutshaped block of adjacent soft tissue. ∘ May also kink vessels, resulting in distal ischaemia. Temporary placement of a spacer • Antibiotic-impregnated PMMA spacers bridge bony defects and maintain limb length. ∘ They are subsequently removed and the defect reconstructed by other means. • The Masquelet technique relies on the ‘induced membrane’ that forms around the cement spacer to revascularise morsellised cancellous bone graft, placed at a second stage. Bone grafting • Delayed cancellous bone grafting is usually performed 6 weeks after injury, when soft tissues have healed. Primary bone shortening and subsequent lengthening • Bone lengthening is accomplished by a circular frame. ∘ Examples: Ilizarov, Taylor Spatial Frame™. • Lengthening at the site of fracture is bone distraction. • Lengthening by corticotomy at a remote site is bone transport. • The bone is lengthened by turning special screws on the frame. ∘ Lengthening usually proceeds at 1 mm/day. • After lengthening, the frame is left in situ for a period of consolidation. Reconstruction with vascularised bone • Common sources include the free fibula and deep circumflex iliac artery (DCIA) flap. ∘ Ribs are usually too thin. • Up to 18 months or more is required for bone strengthening and hypertrophy. ∘ During this period, full weight-bearing risks fracture. The Lower Limb 435 Acute compartment syndrome • Compartment syndrome is elevation of interstitial pressure in a closed osseofascial compartment that results in microvascular compromise. • It is a surgical emergency. • Missed diagnosis causes irreversible neuromuscular ischaemia and significant long-term morbidity. • Compartment syndrome can be caused by: ∘ Fractures, both closed and open – Never assume open fractures concomitantly decompress compartments. ∘ Soft tissue trauma ∘ Arterial injury ∘ Prolonged limb compression in an obtunded patient ∘ Burns. • Anterior and deep posterior compartments of the lower leg are most affected. ∘ These are also the most frequently missed during fasciotomy. Pathophysiology • Compartment syndrome begins with some form of tissue injury. • This disturbs normal tissue homeostasis, leading to increased tissue pressure. • When tissue pressure exceeds capillary pressure, capillary blood flow decreases. • Causes hypoxia and local tissue necrosis. • This worsens the degree of tissue injury, forming a vicious circle. • Capillary pressure is governed by Starling forces, which include: ∘ Capillary and interstitial hydrostatic pressure ∘ Capillary and interstitial oncotic pressure. • Capillary hydrostatic pressure varies from individual to individual. ∘ Typical values: 35 mmHg at the arteriolar side; 15 mmHg at the venular end of the capillary. – Compartment syndrome therefore occurs well below arterial blood pressure. Clinical features • Pain out of proportion to that expected from the injury. ∘ Most important sign. • Pain with passive motion of muscles passing through the compartment. • Paraesthesia or numbness in the territory of nerves passing through affected compartments. • Tightness of the involved compartment. • Weakness. • Compartment syndrome does not usually cause absent peripheral pulses. ∘ This suggests possibility of vascular injury. • Presence of pulses does not exclude compartment syndrome. • Adequate examination may not be possible in these circumstances: ∘ Multiple injuries ∘ Impaired consciousness 436 Chapter 6 ∘ ∘ After regional anaesthesia or peripheral nerve injury Young age. • In such cases, compartment syndrome cannot be excluded clinically. • Compartment pressures should therefore be measured. Measurement of compartment pressures • Some units monitor compartment pressures in all patients with lower leg fractures. • Measurement is not necessary if the diagnosis is unequivocal. • Pressure is measured by inserting a needle into a compartment. • The needle is connected to a proprietary device, e.g. Stryker® Intracompartmental Pressure Monitor System. • Alternatively, the needle can be connected to an arterial line set-up. ∘ Available in most operating theatres and intensive care units. • Ideally, measurements are taken from all four compartments of the lower leg. ∘ The deep posterior compartment is difficult to access. • Compartments should be decompressed if the pressure remains: ∘ >30 mmHg ∘ ≤30 mmHg below diastolic blood pressure. Techniques of calf fasciotomy • For trauma, decompressing all four compartments is recommended. Double incision fasciotomy • Current UK Standards recommend this technique after open tibial fractures. • Incisions preserve septocutaneous vessels from the posterior tibial artery and peroneal artery, which may supply local fasciocutaneous flaps. • Think ‘mark twice, cut once’ to avoid misdirecting incisions. ∘ Inadvertently exposing the tibia or peroneal tendons causes additional morbidity. 1 Two skin incisions: ∘ Medial longitudinal incision 1–2 cm posterior to medial tibial border. ∘ Lateral longitudinal incision 2 cm lateral to anterior tibial border. – These are also lines of election for pretibial wound extension after open tibial fracture. 2 Both posterior compartments are decompressed through the medial incision. ∘ Posterior tibial neurovascular bundle is at risk during decompression of the deep posterior compartment. ∘ The tibial attachment of soleus is released to access the proximal part of the deep posterior compartment. 3 Anterior and peroneal compartments are decompressed through the lateral incision. ∘ Anterior compartment is directly deep to the lateral incision. ∘ Subfascial dissection proceeds laterally within the anterior compartment. ∘ The anterior intermuscular septum is divided to decompress the peroneal compartment into the anterior compartment. ∘ A ‘poke test’ can confirm both compartments have been decompressed: – A finger is inserted subfascially and ‘poked’ medially – hitting the tibia confirms the anterior compartment has been entered. The Lower Limb 437 – The finger is then poked posteriorly – hitting the fibula confirms the anterior intermuscular septum has been opened. Compartments of the leg and fasciotomies Anterolateral incision Fibula Deep posterior compartment Superficial posterior compartment Posteromedial incision A Anterior compartment Lateral compartment Tibia C D B M N E L G F K H I J A. Tibialis anterior B. Extensor hallucis longus C. Extensor digitorum longus D. Peroneus brevis E. Peroneus longus F . Tibialis posterior G. Flexor digitorum longus H. Flexor hallucis longus I. Soleus J. Gastrocnemius K. Posterior tibial vessels, tibial nerve L. Peroneal vessels M. Anterior tibial vessels, deep peroneal nerve N. Superficial peroneal nerve • The classic double incision fasciotomy (Mubarak and Hargens) differs from UK Standards: ∘ The lateral incision is more lateral, a few centimetres anterior to the fibula. ∘ Plane of undermining is suprafascial. • This technique is more appropriate for closed injuries: ∘ There is no need to preserve fasciocutaneous perforators. ∘ Important not to convert a closed fracture into an open one, with bone exposure. • This is favoured by the military because incisions are easily adapted for amputation when a limb is unsalvageable. Single incision fasciotomy • Described by Davey, Rorabeck and Fowler. • A single lateral incision is made in line with the fibula. ∘ Suprafascial dissection anteriorly accesses anterior and lateral compartments. ∘ Suprafascial dissection posteriorly accesses posterior compartments. • Originally described for chronic exertional compartment syndrome in athletes. • For trauma cases where soft tissues are swollen and distorted, the double incision technique is considered safer. Amputation • Indicated in three circumstances: 1 Immediately, for life saving damage control surgery. – After multi-level vascular injury and haemorrhage following ballistic trauma. – After crush injuries with warm ischaemia >6 hours. 438 Chapter 6 – The military paradigm involves radical debridement, which removes the unsalvageable limb without planning closure of the stump per se. • This preserves as much length of viable tissue as possible. – Definitive amputation is performed 48–72 hours later as a semi-elective procedure. 2 Early, when limb salvage is either impossible or would give a suboptimal result. – Incomplete traumatic amputation with an injured distal remnant. – Avascular limb with warm ischaemia 4–6 hours. – Segmental muscle loss affecting >2 compartments. – Segmental bone loss > 1∕3 length of tibia. – Severe open foot injury. 3 Late, after failed limb salvage with a stiff, useless, painful limb. – The aim of early decision making is to avoid this situation. – Early amputation gives better functional results than late amputation. • Preferred levels of amputation: ∘ Transtibial (‘below knee’) ∘ Transfemoral (‘above knee’). • Try to preserve the knee joint and proximal tibial length. ∘ Energy requirements of mobilising on a transtibial stump are lower than on a transfemoral stump. ∘ Long-term function and quality of life is superior with transtibial amputation. • This may require revascularisation or flap coverage. ∘ A fillet-of-sole flap, incorporating calcaneus, can be used for this purpose. Limb salvage versus primary amputation • The Lower Extremity Assessment Project (LEAP) is a multicentre study of severe lower limb trauma in the US civilian population. ∘ It found no difference in functional outcome between patients who underwent either limb salvage surgery or primary amputation. • The decision on whether to undertake primary amputation can be complex. ∘ Should involve at least two Consultant surgeons and, where possible, the patient and family. • Anatomical and functional deficits resulting from the injury are taken into account: ∘ Absent or altered plantar sensation is not a good predictor of long-term function (LEAP study). • Physiological, psychological and socioeconomic factors are also considered. Osteomyelitis • Osteomyelitis (OM) is inflammation of bone caused by an infecting organism. Classification Duration • There is little agreement on these time limits, which are arbitrary: ∘ Acute – less than 2 weeks The Lower Limb ∘ ∘ 439 Subacute – between 2 weeks and 1 month Chronic – more than 1 month. Mechanism of infection • Exogenous ∘ Open fracture ∘ Surgery ∘ Local soft tissue infection • Haematogenous ∘ Bacteraemia. Host response • Pyogenic • Non-pyogenic. Acute OM • The pathology of acute OM is different from chronic OM. • Bimodal age distribution, affecting children <2 or 8–12 years old. ∘ Typically involves metaphyses of rapidly growing long bones. ∘ Uncommon in immunocompetent individuals after the physes close. Pathology 1 Haematogenous bacterial seeding causes an inflammatory reaction. 2 This can cause local ischaemic necrosis of bone, resulting in an abscess. 3 The abscess causes increased intramedullary pressure, leading to cortical ischaemia. 4 Pus under pressure escapes into the subperiosteal space through a cloaca in the cortex. • Left untreated, this progresses to sequestrum formation and chronic OM. ∘ Sequestrum is dead bone that has separated from normal bone by necrosis. ∘ Involucrum is a thick sheath of new bone formation where periosteum has been lifted off as a result of pyogenic OM. • Common causative organisms include: ∘ Staphylococcus aureus or Group B Streptococcus in children ∘ Pseudomonas aeruginosa in intravenous drug abusers ∘ Fungi in the immunosuppressed ∘ Salmonella in sickle cell disease. Investigation • Blood cultures are positive in 40% of cases. • Isolating the causative organism by needle aspiration of the subperiosteal space and marrow cavity is pivotal. • Bony changes are visible on plain X-ray after 12 days. • Technetium-99 m bone scans can be positive after 24–48 hours. • MRI shows early inflammatory change in bone marrow. Treatment • Intravenous antibiotics are the mainstay of treatment. 440 Chapter 6 • Surgery is indicated for drainage of a sequestrum: ∘ A cortical window is made, followed by debridement of necrotic tissue. Chronic OM • The hallmark of chronic OM is infected dead bone within a compromised soft tissue envelope: ∘ Infected foci within bone are surrounded by sclerotic, relatively avascular bone. ∘ This is covered by thickened periosteum, scarred muscle and subcutaneous tissue. • This arrangement makes systemic antibiotics relatively ineffective. • Secondary infections are common: ∘ Samples from sinus tracts grow different types of bacteria than those detected on bone biopsy. • Eradication of chronic OM is difficult. ∘ Requires effective antibiotics and aggressive surgery. – This may not be suitable for all patients. Classification • The Cierny and Mader Staging System for Chronic OM accounts for host physiology and anatomy of the OM. Anatomical type • I: Medullary – endosteal disease • II: Superficial – cortical surface infected due to coverage defect • III: Localised – cortical sequestrum, excisable without causing instability • IV: Diffuse – Features of types I, II and III with mechanical instability before or after debridement. Physiological class • A: Normal • B: Compromised – local or systemic factors compromising immunity or healing • C: Prohibitive – minimal disability, prohibitive morbidity anticipated, poor prognosis for cure. Cierny and Mader staging system for chronic osteomyelitis I : Medullary II : Superficial III : Localised IV : Diffuse Source: Cierny and Mader (1987). Reproduced with permission from Frontline Medical Communications. The Lower Limb 441 Investigation • Diagnosis is based on clinical, laboratory and imaging data. • Gold standard is bone biopsy, sent for histological and microbiological analysis. • Plain X-rays, sinograms, CT and MRI can support the diagnosis and help delineate the anatomy. ∘ Signs on plain X-ray: cortical destruction, periosteal reaction. Treatment • Treatment choice takes into account the Cierny and Mader stage: ∘ Simple versus complex treatment ∘ Curative versus palliative treatment ∘ Limb sparing versus limb ablation. • Treatment is planned in a multidisciplinary team setting: ∘ Orthopaedic surgeons ∘ Plastic surgeons ∘ Infectious diseases specialists ∘ Medical microbiologists. • Surgery provides the only chance of complete cure. ∘ Complemented with long-term antibiotics, based on bone culture results. • Goal of curative surgery is eradication of infection by achieving a viable and vascular environment. • This involves: 1 Debridement of affected bone and soft tissues. – Instability is treated with a circular frame. 2 Dead space management – Requires importation of vascularised soft tissue, usually a free flap. – An alternative to flap transfer is the Papineau technique of open bone grafting: • Debridement, followed by daily moist dressings until granulation tissue is present throughout the wound. • The bony cavity is then filled with strips of autogenous cancellous bone graft. • The exposed wound and bone graft are covered with moist, antibiotic-impregnated gauze. • A modified technique using negative pressure wound therapy has been described. • When the bone graft is overgrown with granulation tissue, the wound is skin grafted. Lymphoedema • Lymphoedema is accumulation of protein-rich interstitial fluid within skin and subcutaneous tissues. • Over time, inflammation, adipose tissue hypertrophy and fibrosis may occur. • This can be disfiguring and limits function. The lymphatic system • Capillary hydrostatic pressure forces proteinaceous fluid into the interstitium. • 80–90% is reabsorbed by venular capillaries. 442 Chapter 6 • The lymphatic system is an accessory route for remaining proteinaceous fluid to return to the venous circulation. • Once interstitial fluid enters the lymphatic system, it is called ‘lymph’. Embryology • Lymphatic vessels, lymph nodes and spleen derive from mesoderm. • Lymphatic vessels develop from the venous system. ∘ Lymph sacs bud from venous endothelial cells. ∘ These sacs coalesce into primitive lymphatic capillaries. ∘ A rudimentary lymphatic system is established by the end of the second gestational month. • Valves are seen in the lymphatic system during the 5th month. Anatomy • The lymphatic system is divided into three parts: 1 Superficial system – Suprafascial, within subcutaneous fatty tissue. – Drains skin and subcutaneous tissue. 2 Deep system – Subfascial, accompanies blood vessels. – Drains muscle, tendon sheaths, nerves, periosteum and joints. 3 Visceral system – Drains intestines, spleen, liver, thymus and lungs. – Lymph from the intestine appears milky due to fatty acids absorbed from the gut. • Perforating lymphatic vessels connect deep and superficial systems. • They are also connected at these sites: ∘ Cubital fossa ∘ Popliteal fossa ∘ Inguinal region. • Lymphoedema is limited to tissue superficial to deep fascia. ∘ Lymphoedema of skeletal muscle does not occur. ∘ Attributed to the pumping action of muscle on lymph transport. Lymphatic vessels • Found in all areas that have a blood supply, except the central nervous system. • Lymph capillaries originate in the peripheries as valveless, blind-ended tubes. ∘ More permeable than blood capillaries because they lack basement membrane. • Lymph precollectors connect the lymph capillaries to the lymph collectors. • Lymph collectors transport lymph to lymph nodes and lymphatic trunks. ∘ 0.1–0.6 mm diameter. ∘ They resemble other vascular structures, with intima, media and adventitia. ∘ Valves feature prominently, every 6–20 mm. – The segment between a pair of valves is called a ‘lymphangion’. • Supplied by autonomic nerves; initiates vessel contraction. The Lower Limb 443 • Lymphatic ducts and trunks are the largest lymphatic vessels. ∘ Left and right lumbar trunks drain lower limbs, lower trunk and external genitalia. ∘ They join the gastrointestinal trunk to form the cisterna chyli. – This is a thin-walled sac, variably located anterior to T11 to L2. ∘ The thoracic duct is the largest lymph trunk, up to 5 mm in diameter. – Runs cranially from the cisterna chyli, alongside the aorta. – Empties 3 litres of lymph per day into the junction of left internal jugular and subclavian veins. – A valve here prevents reflux of blood into the lymphatic system. ∘ The right lymphatic duct is formed by the confluence of right jugular, supraclavicular, subclavian and parasternal trunks. ∘ 1.5 cm long; drains into the junction of right internal jugular and subclavian veins. Lymph nodes • Kidney-shaped aggregates of lymphoid tissue. • Contain macrophages, plasma cells and lymphocytes that filter waste products: ∘ High molecular weight proteins ∘ Fats ∘ Cellular debris ∘ Foreign organisms, such as viruses and bacteria. • Blood capillaries within lymph nodes absorb much of the water in lymph. • Lymph nodes also produce lymphocytes. Function 1 Transport lymph from interstitial spaces to large neck veins. 2 Maintain fluid homeostasis. 3 Regulation of immunity. • Lymph is propelled up the lymphatic channels by a combination of: ∘ Extrinsic skeletal muscle action ∘ Intrinsic smooth muscle action ∘ Respiratory movement ∘ Adjacent arterial pulsation. Pathogenesis • Lymphoedema occurs due to insufficiency of the lymphatic system. • Untreated lymphoedema leads to stagnation of water, protein and waste products in the interstitium. • Tissue damage, increased diffusion distances and impaired circulation of macrophages and lymphocytes increase susceptibility to infection. • Episodes of cellulitis and lymphangitis further increase damage to lymphatics. • Pathogenesis is attributed to two mechanisms, which may coexist: 1 High volume insufficiency 2 Low volume insufficiency. 444 Chapter 6 Simple oedema • Simple oedema is the accumulation of low-protein fluid in the interstitium. ∘ Causes swelling and pitting oedema. • Simple oedema is a sign, rather than a diagnosis caused by: ∘ Cardiac insufficiency ∘ Immobility ∘ Chronic venous insufficiency ∘ Hypoproteinaemia ∘ Pregnancy ∘ Medication, such as calcium channel blockers or non-steroidal anti-inflammatory drugs (NSAIDs). High volume insufficiency • Lymphatic load exceeds transport capacity of an intact lymphatic system. • May result from chronic simple oedema: ∘ Persistent oedema (months) causes secondary damage of lymphatics: – Intra-lymphatic pressure increases. – Causes damage to vessel walls and valves, resulting in fibrosis and protein leak. – High protein concentration increases interstitial oncotic pressure – This favours accumulation of water. • The resulting high-protein oedema is lymphoedema. Low volume insufficiency • Reduced transport capacity cannot deal with normal quantities of lymph. • Common causes: surgery, radiation, filariasis. Classification • Lymphoedema is primary or secondary, based on its aetiology. Primary lymphoedema • Developmental abnormality. ∘ Lymph vessel abnormalities are most common. ∘ More rarely, fibrosis or agenesis of lymph nodes. • Abnormalities are believed to be present at birth, but may not manifest as lymphoedema until later in life. Age of onset • Primary lymphoedema can be classified according to age of onset: Lymphoedema congenita • Congenital cases may occur due to VEGFR3 gene mutation. • Lymphoedema is present at birth or within 2 years of birth. • Accounts for 10% of primary lymphoedema. • Three times commoner in females. The Lower Limb 445 • 60% occurs in the lower limb. • Lymphangiography typically shows severe hypoplasia or aplasia. • Familial lymphoedema congenita is known as Nonne-Milroy syndrome. Lymphoedema praecox • Most common type of primary lymphoedema; accounts for 80%. • Lymphoedema first noticed between 2 and 35 years, typically at puberty. • Up to 10 times commoner in females. ∘ Oestrogen is hypothesised to have a role in the pathogenesis. • Most are unilateral; left leg affected more frequently than the right. • Lymphangiography typically shows hypoplasia. • Familial lymphoedema praecox is known as Meige disease. Lymphoedema tarda • Lymphoedema becomes apparent after 35 years. • Accounts for 10% of cases. • Lymphangiography typically shows hyperplasia. Secondary lymphoedema • Classified by its cause; the mnemonic includes five ‘I’s: 1 Invasion by tumour – Primary lymphatic tumours – Secondary tumours. 2 Infection – Most common worldwide cause is filariasis. • Caused by the Wuchereria bancrofti parasite, transmitted by mosquitos. • Can result in massive swelling of legs and genitalia, known as elephantiasis. – Lymphogranuloma, TB, recurrent infections. 3 Inflammation – Snake or insect bites – Burns. 4 Irradiation 5 Iatrogenic causes – Lymph node dissection for malignancy. • Most common cause in the Western world. – Varicose vein stripping, chronic venous insufficiency. Staging • Lymphoedema is typically a progressive disease. • Untreated lymphoedema progresses through these stages, as defined by the International Society of Lymphology: Stage 0 • Also known as the subclinical stage. 446 Chapter 6 • Swelling not evident despite impaired lymph transport. • May exist for months or years before oedema becomes evident. Stage I • Also known as the reversible stage. • Pitting oedema subsides with limb elevation. • No secondary soft tissue changes. Stage II • Also known as the spontaneously irreversible stage. • Lymphostatic fibrosis, hardening of tissues, eventual loss of pitting oedema. • Swelling does not reduce significantly with elevation. • There may be frequent soft tissue infections. • Stemmer’s sign is positive: ∘ A dorsal fold of skin can normally be pinched at the base of the second toe or middle finger. ∘ Stemmer’s sign is positive if the skin cannot be pinched and lifted. ∘ Considered an accurate test to diagnose extremity lymphoedema. ∘ Negative Stemmer’s sign does not exclude lymphoedema. Stage III • Also known as lymphostatic elephantiasis. • Extreme increase in volume. • Skin thickening, hyperpigmentation, deep skin folds, fat deposits, papillomas. • Within each stage, swelling can be assessed by volume as: ∘ Mild: <20% excess limb volume ∘ Moderate: 20–40% excess limb volume ∘ Severe: >40% excess limb volume. Clinical diagnosis • Lymphoedema may be confused with: ∘ Lipodystrophy – Sometimes referred to as ‘lipoedema’. – Classically stops at the ankles; does not involve feet. ∘ Myxoedema ∘ Oedema, due to: – Cardiac, pulmonary, hepatic or renal causes – Gastrointestinal, gynaecological or urological causes – Infectious diseases. ∘ Deep venous thrombosis ∘ Ruptured Baker’s cyst. • Simple oedema is distinguished from lymphoedema as follows: ∘ Established lymphoedema is non-pitting. ∘ Oedema usually improves within hours of elevation. ∘ Lymphoedema improves within days of elevation. The Lower Limb ∘ ∘ 447 Lymphoedematous skin is thick and hyperkeratotic. Secondary lymphoedema has a definable cause. Assessment of limb swelling • Serial photography; standardised circumferential limb measurement. • Limb volume can be assessed by water displacement (Archimedes’ principle). • Other methods: 3D cameras, perometry (using lasers or light to calculate volume). • Oedema is diagnosed if limb volume is >10% more than the normal limb. Malignant transformation • Malignant transformation (lymphangiosarcoma) occurs in 10% of severely affected patients after 10 years. ∘ 5 year survival following lymphangiosarcoma is <10%. • Stewart–Treves syndrome is angiosarcoma arising within a chronically lymphoedematous upper limb, following mastectomy and axillary lymph node dissection for breast cancer. ∘ Prognosis is poor despite treatment. Investigation Direct lymphangiography • • • • Patent blue dye is injected into the dorsal foot or hand to identify lymphatics. Lymph trunks are then cannulated and injected with oily radio-opaque contrast. Lymph channels are then imaged radiologically. Seldom used – may worsen lymphoedema by damaging valves, causing fibrosis. Indirect lymphangiography • Water-soluble contrast material is injected intracutaneously. • Contrast is preferentially absorbed by the fine lymphatic capillaries. • The lymphatic system is then demonstrated radiologically. • Regional lymph nodes cannot be identified by this method. Lymphoscintigraphy • This has largely replaced direct lymphangiography. • Radioactive tracer is injected intradermally and taken up by lymphatics. ∘ Can also be injected subfascially to visualise the deep system. • A gamma camera visualises radiation emitted by the tracer, providing a map. ∘ Also shows rate of lymph uptake and movement through lymph vessels. • Technetium-99 m is often used to label tracers, e.g. dextran, sulphur colloid, albumin. Indocyanine green (ICG) lymphography • Relatively new imaging method. • ICG is a fluorescent dye that binds to plasma proteins. ∘ The absorption and fluorescence spectrum of ICG is near-infrared. • Injected intradermally; taken up by lymphatic capillaries. • Dynamic images of superficial lymphatic flow are obtainable within minutes. ∘ Requires illumination of the skin surface with a near-infrared light source. 448 Chapter 6 ∘ ICG emission is detectable by special cameras, such as the Photodynamic Eye (PDE) or SPY® System. • Can be used intraoperatively to map lymphatics and verify results of surgery. Magnetic resonance lymphography • Machines with powerful 3T magnets can produce detailed images without the need for contrast injection. Non-surgical management • The keystone of lymphoedema management is patient education. • Rapid progression of lymphoedema can be prevented by: ∘ Skin care and hygiene ∘ Exercise and movement ∘ Simple lymphatic drainage (self-massage) ∘ Maintenance of ideal body weight ∘ Compression garments ∘ Avoidance of extremes of temperature, injury, tight clothing or jewellery ∘ Elevation ∘ Seeking early treatment for infections or increasing swelling. Complex decongestive physiotherapy • Described by Földi; considered by many to be the gold standard treatment. ∘ However, it is labour intensive and requires dedication by the patient. • Consists of four components administered in two phases: 1 Manual lymphatic drainage (MLD) – Specialised massage; redirects lymph flow to intact lymphatics. 2 Skin care – Antiseptic washes and emollients. 3 Compression – Multilayer inelastic lymphoedema bandaging in phase one. – Most are fitted with compression garments in phase two. 4 Remedial exercises – Combine elevation with muscle action to ‘pump’ lymphoedema out. • Phases of treatment: 1 Intensive phase – Often requires hospitalisation – treatment is given daily. 2 Maintenance phase – Outpatient treatment; emphasis on self-treatment under supervision. Pharmacological treatment Albendazole and diethylcarbamazine • Anthelmintic drugs, used in combination, to treat filariasis. ∘ They kill microfilariae in the blood. ∘ Also kill some adult worms in lymphatic vessels. The Lower Limb 449 • Treatment is most effective early, when worms are small. ∘ As worms get bigger, they block lymphatics after they die. ∘ In advanced disease, lymphoedema does not resolve after treatment. Antibiotics • Infection in lymphoedema is treated aggressively with antibiotics. ∘ Cellulitis and other infections can cause fibrosis that worsens lymphoedema. • Protracted courses (weeks) are usually required. • Recurrent infections may require prophylactic antibiotics. Diuretics • Should not be used to treat lymphoedema. • They remove the water, but not protein, of lymphoedema. • This leaves high concentrations of interstitial protein, leading to fibrosis and inflammation. • High protein concentrations also attract water back into the interstitium. Surgical management • It is said <10% of lymphoedema patients would benefit from surgery. • No surgical procedure provides a reliable cure for lymphoedema. • Surgery is classified as: 1 Excisional 2 Physiological. Excisional techniques • Debulking skin and subcutaneous tissue also removes some remaining functioning lymphatics. ∘ This interferes with subsequent attempts at MLD. • Excisional techniques are reserved for advanced, fibrosed lymphoedema with elephantiasis. Charles procedure (1912) • It is not clear whether Charles specifically described this technique. • Nevertheless, his name is associated with circumferential excision of lymphoedematous tissue. ∘ The sole of the foot is not excised. ∘ Split-skin graft is applied to fascia. • Harvesting skin graft from the excision specimen was described subsequently. • Significant risk of complications: ∘ Hypertrophic scarring and contracture ∘ Sensory impairment ∘ Exophytic keratosis and papillomatosis ∘ Graft loss and ulceration ∘ Aggravation of foot lymphoedema. 450 Chapter 6 Homans procedure (1936) • Near-total excision of subcutaneous fat in four staged operations. ∘ At each stage, long thinned skin flaps are used to cover the deep structures. • Circumferential deep fascial excision is also performed. Thompson procedure (1962) • Aims to bring superficial lymphatics into contact with deep lymphatics to improve lymph drainage: ∘ A thin mid-lateral skin flap is raised along the whole length of the limb. ∘ Underlying subcutaneous tissue and deep fascia are excised. ∘ The skin flap is replaced, with the redundant free edge de-epithelialised and buried into a muscle compartment. • Thompson states the principal indication of his operation is treatment of enlarged limbs with readily pitting oedema, in the presence of valved superficial lymphatics. ∘ Such cases can also be treated with complex decongestive physiotherapy. Liposuction • Chronic lymphoedema can lead to adipocyte proliferation and fat deposition. • Resulting limb enlargement may not fully respond to non-operative treatment. • Circumferential liposuction can remove excess fat, improving limb contour. ∘ However, compression garments are required to maintain the result. ∘ Critics state liposuction might induce fibrosis, worsening lymphoedema. Physiological techniques • These aim to improve lymphatic drainage of the limb. • None of the operations have proved universally successful. • In particular, these techniques have not shown long-term benefit: ∘ Lymphangioplasty – Strands of silk implanted in subcutaneous tissue to draw lymph fluid proximally by capillary action. ∘ Omental transposition – Portion of omentum pedicled to the affected limb. ∘ Enteromesenteric bridge – Pedicled segment of ileum applied to the cut surface of the most proximal normal lymph nodes. • Physiological treatments for lymphoedema include: Lymphaticovenous shunts • Lymphatic vessels anastomosed to veins. • Requires intact distal lymphatics – usually the case in secondary lymphoedema. • Not suitable for long-standing lymphoedema due to lack of patent lymphatics. • Supramicrosurgical techniques allow 0.3 mm vessels to be anastomosed. Lymphaticolymphatic anastomosis • Autologous lymphatic vessel grafts are used to bridge obstructed lymphatic segments. ∘ Vascularised lymphatic vessel transfer is also described. The Lower Limb 451 • May be useful in cases with a short segment of absent lymphatics. • Patency of both lymphaticovenous and lymphaticolymphatic anastomoses has been demonstrated in the short term, however there is doubt whether elevated interstitial pressures in the longer term leads to thrombosis. Vascularised lymph node transfer • This technique follows one of these two philosophies: 1 Transferring lymph nodes to bridge a gap in the normal path of lymphatic drainage. – Usually a proximal site, e.g. after axillary clearance for breast cancer. 2 Transferring lymph nodes to a distal site, e.g. ankle or wrist, to act as a pump. – Usually the most dependant areas; these offer an unscarred field. • Lymph nodes can be harvested from axilla, groin, submental or supraclavicular areas. ∘ Risk of causing secondary lymphoedema if harvested from axilla or groin. ∘ Some therefore advocate intraoperative lymphatic mapping to avoid morbidity. • In addition to lymph drainage, transferred lymph nodes may stimulate lymphangiogenesis by production of VEGF. • Incorporation of superficial inguinal lymph nodes with a free DIEP flap breast reconstruction has been described. ∘ Nodes are placed in the axilla, and a second anastomosis of the SIEA system to thoracodorsal vessels can be done to ensure vascularity. Pressure ulcers • A pressure ulcer is a localised injury to the skin and/or underlying tissue, usually over a bony prominence, as a result of pressure or pressure in combination with shear. ∘ The microclimate, that is moisture and temperature, also contributes to pressure ulcers. • The term ‘bedsore’ or ‘decubitus ulcer’ should be avoided. ∘ ‘Decubitus’ derives from the Latin decumbere, meaning ‘to lie down’. – However, ischial ulcers occur in seated patients. • Pressure ulcers develop in 3–14% of hospitalised patients. • Pressure ulcers are associated with fivefold increased mortality in the elderly. ∘ Up to a third of such patients die in hospital. • Pressure ulcers tend to occur in: ∘ The old ∘ The hospitalised ∘ The young neurologically impaired. Anatomical distribution • Vast majority occur below umbilical level; in descending order of frequency: ∘ Sacrum ∘ Heel ∘ Ischium ∘ Elbow ∘ Malleolus ∘ Trochanter ∘ Knee 452 Chapter 6 ∘ ∘ Scapula Occiput. • Pressure ulcers also occur with medical devices, e.g. nasogastric tubes. Pathogenesis • Pressure ulcers are initiated by extrinsic factors and propagated by intrinsic factors. Extrinsic factors Pressure • Prolonged pressure causes tissue ischaemia, leading to necrosis and ulceration. • Low pressure over a long period of time causes ulceration as effectively as high pressure over a short period. • Necrosis first occurs in tissues closest to the bone, usually muscle. • Skin necrosis occurs late and to a lesser degree than in the deeper tissues. ∘ Results in a characteristic cone-shaped wound – the degree of skin loss is the tip of the iceberg. Shear • Mechanical stress applied parallel to the skin’s surface. • Occurs when a seated patient slides down in a chair. ∘ Skin moves in the opposite direction to bone. • In such circumstances, less pressure is required to occlude blood vessels. Friction • Opposes movement of one surface against another. • Occurs when a patient is dragged across a surface, or due to ill-fitting shoes. • Results in loss of epidermis, which may initiate or accelerate pressure ulceration. Intrinsic factors General • Old age • Immobility • Acute illness or terminal illness • Impaired nutrition or hydration ∘ Low lean body mass ∘ Anaemia • Impaired perfusion ∘ Diabetes ∘ Smoking ∘ Peripheral vascular disease ∘ Use of vasopressors. Local • Local ischaemia or fibrosis The Lower Limb 453 • Decreased sensation • Loss of autonomic control • Skin moisture ∘ Excessively dry or moist skin both contribute to pressure ulceration ∘ Urinary and faecal incontinence • Infection. Classification • European Pressure Ulcer Advisory Panel (EPUAP) and American National Pressure Ulcer Advisory Panel (NPUAP) classify pressure ulcers into these categories or stages. ∘ The term ‘category’ is used because ‘stage’ incorrectly implies that pressure ulcers progress through stages I to IV, and heal from IV to I. Category I: Non-blanchable erythema • Intact skin with non-blanchable redness of a localised area, usually over a bony prominence. • Discolouration, warmth or induration may be indicators in individuals with dark skin. Category II: Partial thickness • Partial thickness loss of dermis presenting as a shallow open ulcer with a red pink wound bed, without slough. Category III: Full thickness skin loss • Subcutaneous fat may be visible but bone, tendon or muscle are not exposed. Category/Stage IV: Full thickness tissue loss • Exposed bone, tendon or muscle. Slough or eschar may be present. ∘ The wound cannot be accurately staged until slough or eschar is removed. Risk assessment • Numerous pressure ulcer risk assessment scores have been devised, e.g. ∘ Norton score (1962) ∘ Waterlow score (1985) ∘ Braden score (1987) The Waterlow score • Updated in 2005 based on new research. • Most widely used risk assessment tool in the United Kingdom. • Patients are scored on these factors: ∘ BMI ∘ Skin type and risk areas ∘ Sex and age ∘ Appetite and weight loss ∘ Continence 454 Chapter 6 ∘ ∘ Mobility Special risks – Tissue malnutrition, neurological deficit, major surgery or trauma, medications. • Scores of 10+ – at risk of developing a pressure ulcer. • Scores of 15+ – high risk of developing a pressure ulcer. • Scores of 20+ – very high risk of developing a pressure ulcer. Prevention Skin care • • • • • Avoid turning a patient onto a body surface that is still reddened. Use skin emollients for skin hydration. Avoid excessive moisture by using a barrier product. Clean and dry skin regularly. Remove particulate matter from beneath the patient. Urinary or faecal diversion • Considered in cases with gross contamination. Nutrition • Best overseen by a multidisciplinary nutritional team. Positioning • Avoid direct contact between adjacent bony prominences. • Heels can be elevated from the bed with a pillow under the calves. • Baclofen, botulinum toxin and diazepam can relieve spasms. • Surgical release of contractures, cordotomy or rhizotomy may be indicated to reduce deformity in some patients. Repositioning • Reduces duration and magnitude of pressure over vulnerable areas of the body. • Frequency of repositioning depends on the patient’s tissue tolerance, mobility, and type of support surface. ∘ More frequent repositioning is required with a standard mattress compared to viscoelastic foam. • In general, bed-bound patients are repositioned at least every 2 hours. • Seated patients are encouraged to change position every 15–30 minutes. Pressure dispersion • Helps reduce pressure ulcer risk. • If repositioning is difficult, alternating-pressure mattresses help load and unload different areas of the body. • In addition, low air-loss beds provide a flow of air to control skin temperature and humidity. The Lower Limb 455 Pressure awareness • Patients and carers should be educated about the effects of pressure. Treatment • • • • Treatment is geared towards optimising wound healing. Many wounds heal with non-operative interventions. The remainder are considered for reconstructive surgery. Many treatments are also applicable to prevention. Non-operative interventions • Optimise wound healing by addressing three main areas: 1 Optimise the patient • Nutrition • Comorbidities, e.g. diabetes or anaemia • Smoking cessation • Medication review • Exclude malignancy • Patient education. 2 Treat the wound pathology • Improve blood flow, e.g. angioplasty • Provide compression therapy for venous insufficiency • Minimise friction, shear and pressure on the wound. 3 Optimise the local healing environment • Bedside debridement of eschar • Treatment of infection ∘ Cellulitis requires simple antibiotics ∘ OM requires more extensive orthopaedic surgery • Maintain adequate wound hydration • Consider negative pressure wound therapy. Surgical intervention Indications for reconstructive surgery • Patients should be fully investigated: ∘ Imaging may reveal a dislocated hip or OM. • Predisposing factors should be corrected if possible. • Preventative measures must be in place pre-operatively to prevent recurrence postoperatively. • Patients with deteriorating conditions are not candidates for reconstruction. • Patients expected to increase their mobility are treated conservatively. ∘ Ulcers improve once pressure is relieved by ambulation. 456 Chapter 6 • Surgery is best suited to: ∘ Well-motivated, young patients ∘ Patients with clinically stable conditions ∘ Patients who will comply with post-operative preventative measures. Principles of surgery 1 Adequate wound excision, including: ∘ Surrounding scar ∘ Underlying bursa - can be delineated by staining with methylene blue ∘ Bone and soft tissue calcifications. 2 Obliteration of dead space. 3 Reconstruction with durable skin. 4 Flaps should not be wasted: ∘ Flaps that can be readvanced (in case of recurrence) should be used. ∘ If possible, territories of future potential flaps should not be violated. 5 Flaps are designed as large as possible. 6 Suture lines should lie away from pressure areas. 7 Large drains are empirically left in place for at least 2 weeks post-operatively. Reconstruction after excision Sacral pressure ulcers • Occur in supine patients. • Can be reconstructed with the gluteus maximus musculocutaneous flap. ∘ Quoted recurrence rate: 16%. • Can be designed as a rotation or V-to-Y advancement flap. • The muscle’s greater trochanter insertion can be divided in non-ambulatory patients. ∘ This increases flap mobility. • Lumbosacral flaps, based on regional perforating vessels, can also be used. • Use of the superior gluteal artery perforator flap is also described. Ischial pressure ulcers • Occur in seated patients. • Recurrence rates are higher following treatment than for sacral ulcers. • Excision of the ischium should be conservative if possible. ∘ Complete removal transfers pressure onto the contralateral ischium. ∘ Excision of both ischial processes can result in perineal ulceration and urethral fistula. • Can be reconstructed with: ∘ Inferior gluteal artery myocutaneous flap, or the equivalent perforator flap. ∘ V-to-Y advancement based on hamstring muscles. – Advantage: potential readvancement in case of recurrence. – Disadvantages: scar tends to lie on the point of maximal pressure; hip flexion places tension on the closure. – Cannot be used in ambulatory patients due to the functional donor deficit. ∘ In ambulatory patients, a posterior (gluteal) thigh fasciocutaneous flap can be used. The Lower Limb 457 Trochanteric pressure ulcers • Arise in patients that lie on their side, often due to hip flexion contractures. • Classically reconstructed with the tensor fasciae latae (TFL) flap. • Overlying skin can be designed as V-to-Y advancement, transposition or hatchet. • A pedicled anterolateral thigh flap can also be used, with vastus lateralis included if additional bulk is required. Hip joint infection • Trochanteric and ischial ulcers can lead to hip joint exposure and destruction. • Managed by the Girdlestone procedure and wide debridement. • Defect typically closed with a large muscle flap, e.g. vastus lateralis. • Rectus femoris can be used for small defects, preserving vastus lateralis for future use. Fillet of thigh • In the context of multiple ulcers where no other options are available, amputation of a leg provides tissue as a fillet of thigh flap. • This is a major undertaking with considerable risks due to long surgery and blood loss. Further reading Venous ulcers van Gent WB, Wilschut ED, Wittens C. Management of venous ulcer disease. BMJ 2010;341:c6045. Lower limb trauma Archdeacon MT, Messerschmitt P. Modern papineau technique with vacuum-assisted closure. J Orthop Trauma 2006;20(2):134–7. Arnež ZM, Khan U, Tyler MP. Classification of soft-tissue degloving in limb trauma. J Plast Reconstr Aesthet Surg 2010;63(11):1865–9. Castillo RC, Bosse MJ, MacKenzie EJ et al.; LEAP Study Group. Impact of smoking on fracture healing and risk of complications in limb-threatening open tibia fractures. J Orthop Trauma 2005;19(3):151–7. Dougherty PJ. Transtibial amputees from the Vietnam War. Twenty-eight-year follow-up. J Bone Joint Surg Am. 2001;83-A(3):383–9. Giannoudis PV, Faour O, Goff T et al. Masquelet technique for the treatment of bone defects: tips-tricks and future directions. Injury 2011;42(6):591–8. Giannoudis PV, Papakostidis C, Roberts C. A review of the management of open fractures of the tibia and femur. J Bone Joint Surg Br 2006;88(3):281–9. Gustilo RB, Anderson JT. Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: retrospective and prospective analyses. J Bone Joint Surg Am 1976;58(4):453–8. Gustilo RB, Mendoza RM, Williams DN. Problems in the management of type III (severe) open fractures: a new classification of type III open fractures. J Trauma 1984;24(8):742–6. Jacobs N, Rourke K, Rutherford J et al. Lower limb injuries caused by improvised explosive devices: proposed ’Bastion classification’ and prospective validation. Injury 2012, 10.1016/j.injury.2012.05.001 (accessed 20th July 2014). 458 Chapter 6 Johansen K, Daines M, Howey T et al. Objective criteria accurately predict amputation following lower extremity trauma. J Trauma 1990;30(5):568–72. Mubarak SJ, Owen CA. Double-incision fasciotomy of the leg for decompression in compartment syndromes. J Bone Joint Surg Am 1977;59(2):184–7. Nanchahal J, Nayagam S, Khan U et al. Standards for the Management of Open Fractures of the Lower Limb. London: Royal Society of Medicine Press, 2009. Paley D, Maar DC. Ilizarov bone transport treatment for tibial defects. J Orthop Trauma 2000;14(2):76–85. Pallister I, Rahman S, Atherton S. The poke test in lower limb fasciotomy: a potentially limb saving technical note. Ann R Coll Surg Engl 2012;94(7):532. Pollak AN, Jones AL, Castillo RC et al.; LEAP Study Group. The relationship between time to surgical debridement and incidence of infection after open high-energy lower extremity trauma. J Bone Joint Surg Am 2010;92(1):7–15. Rajasekaran S, Naresh Babu J, Dheenadhayalan J et al. A score for predicting salvage and outcome in Gustilo type-IIIA and type-IIIB open tibial fractures. J Bone Joint Surg Br. 2006;88(10):1351–60. Richard BM. Interosseous transfer of tibialis posterior for common peroneal nerve palsy. J Bone Joint Surg Br 1989;71(5):834–7. Webb LX, Bosse MJ, Castillo RC et al.; LEAP Study Group. Analysis of surgeon-controlled variables in the treatment of limb-threatening type-III open tibial diaphyseal fractures. J Bone Joint Surg Am 2007;89(5):923–8. Osteomyelitis Cierny G 3rd, Mader JT. Approach to adult osteomyelitis. Orthop Rev 1987 Apr;16(4):259–70. Lymphoedema Becker C, Arrive L, Saaristo A et al. Surgical treatment of congenital lymphedema. Clin Plast Surg 2012;39(4): 377–84. Campisi C, Bellini C, Campisi C et al. Microsurgery for lymphedema: clinical research and long-term results. Microsurgery 2010;30(4):256–60. Dumanian GA, Futrell JW. The Charles procedure: misquoted and misunderstood since 1950. Plast Reconstr Surg 1996;98(7):1258–63. Kinmonth JB, Taylor GW, Tracy GD et al. Primary lymphoedema; clinical and lymphangiographic studies of a series of 107 patients in which the lower limbs were affected. Br J Surg 1957;45(189):1–9. Koshima I, Inagawa K, Urushibara K, Moriguchi T. Supermicrosurgical lymphaticovenular anastomosis for the treatment of lymphedema in the upper extremities. J Reconstr Microsurg 2000;16(6):437–42. Lin CH, Ali R, Chen SC et al. Vascularized groin lymph node transfer using the wrist as a recipient site for management of postmastectomy upper extremity lymphedema. Plast Reconstr Surg 2009;123(4):1265–75. Lymphoedema Framework. Best Practice for the Management of Lymphoedema. International consensus. London: MEP Ltd, 2006. Wolfe JH, Kinmonth JB. The prognosis of primary lymphedema of the lower limbs. Arch Surg 1981;116(9): 1157–60. Pressure ulcers European Pressure Ulcer Advisory Panel and National Pressure Ulcer Advisory Panel. Prevention and treatment of pressure ulcers: quick reference guide. Washington DC: National Pressure Ulcer Advisory Panel, 2009. Powers KL, Phillips LG. Pressure sores. In: Thorne CH (ed). Grabb and Smith’s Plastic Surgery, 7th edition. Philadelphia: Lippincott Williams & Wilkins, 2014: 989–997. CHAPTER 7 The Trunk and Urogenital System CHAPTER CONTENTS Open abdomen, 459 Perineal reconstruction, 464 Hypospadias, 471 Bladder exstrophy-epispadias complex, 481 Ambiguous genitalia, 482 Vaginal agenesis, 485 Penile reconstruction, 486 Further reading, 488 Open abdomen • An abdominal wall defect created by intentionally leaving an abdominal incision open at the completion of surgery, or by opening or re-opening the abdomen for abdominal compartment syndrome. ∘ Also known as a ‘laparostomy’. ∘ Abdominal wound dehiscence is a major post-operative complication with high mortality. • Abdominal wall tissue loss following trauma or tumour also produces significant defects. Anatomy • In general terms, the anterior abdominal wall is composed of: ∘ Skin ∘ Subcutaneous fat within Camper’s fascia ∘ Scarpa’s fascia (below the level of the umbilicus only) ∘ Sub-Scarpa’s fat ∘ Anterior rectus sheath centrally, aponeuroses of the oblique muscles laterally ∘ Muscles ∘ Posterior rectus sheath (above the arcuate line only) ∘ Transversalis fascia ∘ Preperitoneal fat ∘ Peritoneum. Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 459 460 Chapter 7 Anatomy of the anterior abdominal wall (a) Above the arcuate line Skin Subcutaneous fat and fascia External oblique Internal oblique Linea alba Rectus abdominis Rectus abdominis Transversus abdominis Transversalis fascia Preperitoneal fat Peritoneum (b) Below the arcuate line Skin Subcutaneous fat and fascia External oblique Internal oblique Linea alba Rectus abdominis Rectus abdominis Transversus abdominis Transversalis fascia Preperitoneal fat Peritoneum Muscles 1 Longitudinally orientated, centrally placed muscles: ∘ Rectus abdominis (RA) ∘ Pyramidalis. 2 Flat, laterally placed muscles: ∘ External oblique (EO) ∘ Internal oblique (IO) ∘ Transversus abdominis (TA). • Aponeuroses of EO, IO and TA fuse lateral to the lateral edge of RA to form the linea semilunaris. • They divide into anterior and posterior laminae to enclose RA in a fascial sheath – the rectus sheath – before fusing again in the midline as the linea alba. • The posterior lamina is deficient below the level of the ASIS; its free edge is the arcuate line. ∘ The arcuate line is approximately 1∕3 the distance from umbilicus to pubic symphysis. • Superior to the arcuate line, the anterior rectus sheath comprises the aponeurosis of EO and the anterior leaf of IO aponeurosis. • The posterior rectus sheath comprises the posterior leaf of IO and TA aponeurosis. • Inferior to the arcuate line, all three of these muscles’ aponeuroses pass anterior to RA. ∘ The posterior surface of RA therefore lies directly on transversalis fascia. • Muscles have segmental nerve supply, usually T6/T7–T12. ∘ EO is also supplied by the iliohypogastric nerve (T12, L1). ∘ IO is also supplied by the iliohypogastric and ilioinguinal (L1) nerves. • All nerves run in the neurovascular plane between IO and TA. The Trunk and Urogenital System 461 Arterial supply • Segmental intercostal and lumbar vessels • Superior epigastric arteries • Superficial and deep inferior epigastric arteries • Superficial and deep circumflex iliac arteries • Superficial external pudendal arteries. Pathogenesis • The abdomen may be left open in these circumstances: ∘ Damage control surgery for trauma ∘ Intra-abdominal sepsis ∘ Excessive visceral oedema that precludes direct closure ∘ Abdominal wound dehiscence. ∘ Following decompression of abdominal compartment syndrome – Intra-abdominal hypertension is defined as >12 mmHg. – Abdominal compartment syndrome is defined as >20 mmHg with organ dysfunction. – Intra-abdominal pressure is usually measured with an intravesical probe. Classification • Björck et al. propose this classification of open abdomen: ∘ Grade 1: Open abdomen without adherence between bowel and abdominal wall or fixity of the abdominal wall (lateralisation). – A: clean – B: contaminated. ∘ Grade 2: Open abdomen with developing adherence/fixity. – A: clean – B: contaminated. ∘ Grade 3: Open abdomen complicated by fistula formation. ∘ Grade 4: Frozen open abdomen with adherent/fixed bowel that cannot be closed surgically, with or without fistula. Management of the open abdomen Three phases: 1 Temporary abdominal closure 2 Patient optimisation 3 Definitive closure. Temporary abdominal closure • Purpose of temporary closure: ∘ Protect intestines ∘ Maintain a sterile (or at least clean) environment ∘ Avoid fluid and temperature loss. • Methods of temporary abdominal closure: ∘ Skin-only closure using towel clips ∘ Silo technique, using non-adherent plastic sheets to wrap around intestines ∘ Temporary mesh 462 ∘ ∘ ∘ Chapter 7 Intraperitoneal packing Negative pressure wound therapy Various proprietary devices. Patient optimisation • Patients are often critically ill. • Optimisation maximises chances of successful reconstruction. • Summarised by the ‘SNAP’ principle: ∘ Sepsis control – both intra-abdominal infection and systemic inflammatory response. ∘ Nutrition – usually requires supplemental enteral or parenteral feeding. ∘ Anatomy – defining the defect by pre-operative imaging. ∘ Planning – determining the type and extent of reconstruction required. Definitive closure • Small wounds may be amenable to delayed primary closure or healing by secondary intention. • May be necessary to skin graft directly on to bowel or granulation tissue to minimise protein losses. • Delayed reconstruction of the myofascial layer may be required months later. • Patients unfit for reconstructive surgery are managed with an abdominal binder. Reconstruction of the myofascial layer 1 Prosthetic 2 Bioprosthetic 3 Autologous. Prosthetic reconstruction • Materials may be meshed or non-meshed; absorbable or non-absorbable. • Meshed materials allow continued drainage of the abdominal cavity. • Granulation can grow through the mesh to permit delayed skin grafting. • Alternatively, mesh can be covered with omentum and skin grafted. ∘ Necessitates leaving a small abdominal defect for the omentum pedicle. • Absorbable meshes are associated with higher rates of fistula and late hernia compared to polypropylene meshes, e.g. Marlex®. Bioprosthetic reconstruction • Acellular dermal matrix (ADM) is popular for abdominal hernia repair. • Tends to form fewer adhesions with bowel compared to prosthetic materials. • Certain ADMs incorporate by regeneration and are replaced by native tissue. ∘ They can therefore be used in infected wounds with relative impunity. • ADMs generally lose integrity when used as ‘bridge grafts’ for ventral hernias, with high recurrence rates. The Trunk and Urogenital System 463 Autologous reconstruction • Fascia lata, used as a graft or pedicled tensor fasciae latae flap. ∘ Can also be transferred as part of an anterolateral thigh (ALT) flap. • Muscle flaps from local or distant sources: ∘ RA, either as a transposition or turnover flap. ∘ EO, for upper abdominal defects. ∘ IO, for lower abdominal defects. ∘ Latissimus dorsi, rectus femoris, vastus lateralis and gracilis may also be used, either pedicled or free. • Components separation ∘ A technique described by Ramirez that allows greater advancement of myofascial layers towards the midline for direct closure. ∘ Releasing incisions are made at pre-determined points in the deep fasciae: 1 EO aponeurosis is divided from the rectus sheath just lateral to the linea semilunaris. 2 RA is separated from the posterior rectus sheath by incising the medial edge of the sheath and freeing the muscle. ∘ Allows bilateral advancement of rectus muscles and anterior rectus sheath: – 5 cm in the epigastrium – 20 cm at the umbilicus – 6 cm in the suprapubic region. Components separation Dehisced linea alba External oblique Internal oblique Transversus abdominis Rectus abdominis Peritoneum Source: Ramirez et al. (1990). Reproduced with permission of Elsevier. 464 Chapter 7 • Tissue expansion ∘ Adjacent myofascial tissue can be expanded prior to advancement. ∘ Expander placement has been described between EO and IO and between IO and TA. Post-operative complications • Relatively common: ∘ Wound dehiscence ∘ Enterocutaneous fistula ∘ Hernia ∘ Infected prosthetic mesh – usually requires removal ∘ Seroma. Perineal reconstruction Anatomy • The perineum is the region of the trunk inferior to the pelvic diaphragm. The pelvic diaphragm • Formed by the two levator ani muscles and two coccygeus muscles. • Levator ani is composed of several parts: ∘ Puborectalis ∘ Pubococcygeus ∘ Iliococcygeus ∘ Levator prostatae or levator vaginae. • These muscles form a hammock between pubis, coccyx and lateral pelvic walls. ∘ This keeps the pelvic contents within the pelvis. • Puborectalis muscles unite posterior to the anorectal junction to form a muscular sling, creating the angle between rectum and anal canal. Boundaries • Perineum boundaries: ∘ Pubic symphysis and inferior pubic rami ∘ Ischial rami and ischial tuberosities ∘ Sacrotuberous ligaments and coccyx. • An imaginary transverse line joining the anterior ends of the ischial tuberosities divides the perineum into two areas: 1 Urogenital triangle anteriorly, containing female external genitalia, or, in males, the root of the scrotum and penis. 2 Anal triangle posteriorly, containing the anus. The urogenital triangle • The urogenital diaphragm is a muscular sheet attached to the sides of this triangle. ∘ Pierced by the urethra and, in the female, the vagina. The Trunk and Urogenital System 465 • The anterior and posterior parts of the diaphragm are formed by the deep transverse perineal muscles. • The middle part is formed by the sphincter urethrae muscle. • Tough fascia overlies (i.e. is superficial to) the urogenital diaphragm, termed the perineal membrane. • Superficial to this membrane is the superficial perineal pouch, containing: ∘ Bulbospongiosus muscle ∘ Ischiocavernosus muscle ∘ Superficial transverse perineal muscle. • In the female: ∘ These muscles are less well developed ∘ The bulbospongiosus is pierced by the vagina. The perineal body • Lies at the midpoint of the line separating urogenital from anal triangles. • It is the tendinous centre of the perineum where several muscles attach, including levator ani and anal sphincters. The anal triangle • Comprises the anus, external anal sphincter, levator ani and ischioanal fossae. • The ischioanal fossae contain: ∘ Internal pudendal vessels. ∘ Pudendal nerve, supplying most perineal sensation. – This neurovascular bundle runs in Alcock’s canal – a fascial tunnel overlying obturator internus in the lateral ischioanal fossa. Regional arterial anatomy • Rich blood supply from two main sources: 1 Femoral artery, giving superficial and deep external pudendal arteries. 2 Internal iliac artery, giving internal pudendal and inferior gluteal arteries. • Branches anastomose freely, allowing design of multiple flaps with robust blood supply. Perineal skin • Perineum contains both specialised and non-specialised skin. • The skin is mobile to accommodate the full range of hip joint movement. • Also accommodates defaecation, sexual intercourse and childbirth. Pathology • Perineal defects most commonly result from: ∘ Resection of gynaecological, colorectal and urological malignancy. ∘ Debridement of sepsis, particularly Fournier’s gangrene. ∘ Inflammatory bowel disease, e.g. Crohn’s disease and ulcerative colitis. ∘ Trauma, e.g. open pelvic fractures. 466 Chapter 7 VIN, VAIN, AIN and invasive malignancy • VIN, VAIN and AIN are potentially premalignant lesions associated with human papilloma virus (HPV) 16 and 18, smoking and immunosuppression. ∘ VIN is vulval intraepithelial neoplasia. ∘ VAIN is vaginal intraepithelial neoplasia. ∘ AIN is anal intraepithelial neoplasia. • Immunisation against HPV may help prevent most of these lesions. • Diagnosis is made on biopsy of suspicious areas. • Dysplastic changes are graded similarly to cervical intraepithelial neoplasia (CIN I, II, III). • High-grade dysplasia is thought to progress to invasive squamous carcinoma in many patients. Treatment of intraepithelial neoplasia • Gold standard treatment of VIN is local excision. ∘ 12–17% of VIN excision specimens contain invasive squamous cell carcinoma (SCC). ∘ 40–60% of VIN lesions progress to invasive SCC. • Alternatives to surgery include topical imiquimod and laser. ∘ Response rates are lower than with surgery; requires close follow-up. • Treatments for VAIN include: ∘ Observation (particularly for localised VAIN I). ∘ Ablation with CO2 laser or cautery. ∘ Surgical excision (particularly for multifocal disease or VAIN III). ∘ Radiotherapy, usually delivered as brachytherapy (particularly for recurrent or multifocal VAIN III). • Treatments for AIN are still being evaluated, but include: ∘ Observation (particularly for AIN I) ∘ Topical imiquimod ∘ Laser or cautery ∘ Surgical excision (particularly for AIN III). Treatment of gynaecological invasive malignancy • Management is planned by a multi-disciplinary team (MDT) in a gynaecological cancer centre. • Most cases are SCCs; vulval melanomas and vaginal adenocarcinomas are rarer. Vulva • SCC usually treated by excision, unless the patient is unfit for surgery. ∘ Primary treatment with radiotherapy can be used in such patients. • Tumours are excised with 1cm margins, including any areas of adjacent VIN. • Larger resections may require a defunctioning colostomy. • Elective inguinal lymph node dissection may be required. Vagina • SCC often treated primarily with chemoradiotherapy. • High posterior tumours may require surgical treatment. The Trunk and Urogenital System 467 • Advanced stage and recurrent tumours also require surgery due to a high incidence of fistulation into bowel or bladder. ∘ Surgery often involves pelvic exenteration, leaving significant dead space. Treatment of anorectal invasive malignancy • Management is planned by a colorectal MDT. • The 2011 Anal Cancer Position Statement by the Association of Coloproctology of Great Britain and Ireland states that plastic surgical input should form part of the anal cancer MDT when reconstruction is considered. • The delayed healing rate of perineal wounds following direct closure is 40–70%. ∘ This decreases to 15–25% with flap reconstruction. Anus • Primary treatment of anal SCC is chemoradiotherapy. • Surgery is done for salvage if the tumour is unresponsive or recurrent. • Usually involves abdomino-perineal resection (APR) of distal rectum and anal skin. Rectum • Low rectal tumours (predominantly adenocarcinomas) usually require APR. ∘ Permanent end-colostomy is formed. • Depending on disease stage, adnexal structures may also be excised: ∘ Posterior vaginal wall ∘ Bladder ∘ Prostate and seminal vesicles. • Multivisceral involvement requires either posterior or total pelvic exenteration. • Coccyx or sacrum may also be excised. • Neo-adjuvant chemoradiotherapy is indicated for advanced tumours. Defect assessment Volume deficit • Superficial lesions may be reconstructed with skin grafts or thin local flaps. • Significant dead space may allow descent of intestines into the pelvis – so-called perineal hernia. • A bulky flap is required in such circumstances. Radiotherapy • Irradiated fields cause these problems: ∘ Preclude the use of local tissues for reconstruction. ∘ Increase incidence of wound-healing problems. ∘ Increase risk of fistulation. Diversion • When faecal and urinary diversion is planned, stoma location on the abdominal wall should be discussed with the MDT if RA is to be used for reconstruction. 468 Chapter 7 Function • Consider whether sexual function, faecal and urinary continence can be restored. Principles of reconstruction • Perineal reconstruction is indicated in these circumstances: 1 Extensive skin loss 2 Vaginal resection 3 Pelvic or perineal dead space 4 Excision of the pelvic floor 5 Excision after radiotherapy. • Reconstruction requires importation of vascularised, non-irradiated tissue of the required type, with the aims of: ∘ Managing dead space. ∘ Providing a substitute for the pelvic floor. ∘ Reconstructing the vagina. Flap options • Pedicled flap options are plentiful due to the rich blood supply. • External pressure exerted during lying, sitting and walking makes free tissue transfer riskier than in other areas. • Commonly used flaps: ∘ Fasciocutaneous – Lotus petal – Superior gluteal artery perforator (SGAP) – Inferior gluteal artery perforator (IGAP) – Posterior thigh – ALT – Pudendal-thigh (‘Singapore’ flap) ∘ Myocutaneous – Vertical rectus abdominis myocutaneous (VRAM) – Inferior gluteal artery myocutaneous (IGAM) – Gracilis ∘ Omentum ∘ Colon. Lotus petal • So-named because the possible skin paddles fan out from the midline like a lotus flower. ∘ In practice, the skin paddle does not have to look like a lotus petal and is designed to fit the defect. ∘ The flap option that lies in the buttock crease is most commonly used. • Based on perforators near the midline of the perineum. The Trunk and Urogenital System 469 • Perforators usually come from the internal pudendal artery as it traverses the ischioanal fossa. • The density of anastomoses in this region makes identification of a named vessel inconsequential. • The flap can be transposed or advanced as a V-Y. SGAP • The superior gluteal artery is a branch of the internal iliac artery. • Emerges from the pelvis superior to piriformis, deep to gluteus maximus. ∘ Surface marking is 1∕3 along a line drawn from posterior superior iliac spine (PSIS) to the apex of the greater trochanter. • Perforator location in some individuals may make it difficult to reach all perineal defects. IGAP • The inferior gluteal artery (IGA) is a branch of the internal iliac artery. • Emerges from the pelvis inferior to piriformis, deep to gluteus maximus. ∘ Surface marking is 1∕2 along a line joining PSIS and ischial tuberosity. • Travels inferolaterally between greater trochanter and ischial tuberosity. • While deep to gluteus it gives many myocutaneous perforators to inferior buttock skin. • Also gives a descending branch – the basis of the posterior thigh flap. Posterior thigh • Based on the descending branch of the IGA. ∘ Can be raised as a large transposition flap based on this. • Alternatively, most of the posterior thigh can be elevated as a large V-Y advancement flap based on IGA and profunda femoris perforators. ∘ Profunda perforators are on a line joining ischial tuberosity to lateral femoral condyle. • The flap is sensate – incorporates the posterior cutaneous nerve of the thigh. ALT • Based on the descending branch of the lateral circumflex femoral artery. • Tunnelled medially, deep to sartorius and rectus femoris, to reach the perineum. ∘ Femoral nerve branches to rectus femoris should be preserved. • Vastus lateralis can be included for additional bulk. Pudendal-thigh (Singapore or Wee flap) • Fasciocutaneous flap based on the posterior labial branch of internal pudendal artery. • Sensory supply is from the posterior labial branch of the pudendal nerve. • Designed on non-hair-bearing skin in the groin crease, lateral to labia majora. • The flap’s base is posterior, at posterior fourchette level. 470 Chapter 7 • For vaginal reconstruction, bilateral flaps are raised and tunnelled to the midline. ∘ Sutured together outside the body to form an ‘inside-out’ tube. ∘ Pushing the tube into the pelvis inverts it, so the skin lines the neo-vagina. VRAM • Based on the deep inferior epigastric artery. • Flap size and reach can be augmented by extending the skin flap obliquely to the costal margin. • Trans-pelvic inset: rotate 180∘ on its long axis and fold posteriorly over the pelvic brim. • Fascial-sparing harvest allows primary closure of the abdominal wall. IGAM • Similar to IGAP, but includes a strip of gluteus maximus (<20% of its width). • Provides additional bulk for dead space management. Gracilis • Raised with or without skin; based on the medial circumflex femoral artery. • The skin paddle is unreliable over the distal muscle. • The vagina can be reconstructed using bilateral gracilis myocutaneous flaps: ∘ Skin paddles are sutured together to fabricate a tube. ∘ Pedicle location limits flap rotation and depth of the neo-vaginal vault. Omentum • Omentum (not the omentum flap) can be pulled inferiorly to fill pelvic dead space. • Not usually robust enough to prevent pelvic descent of intestines. • May not be available for use in all patients, e.g. previous abdominal surgery. Colon • A 12–14 cm segment of rectosigmoid can be transposed to the perineum, based on the superior haemorrhoidal artery. • Bowel lumen is sutured closed at one end to form a blind-ending tube. • This reconstructs a vagina, but is prone to over-secretion of mucus. Reconstructive strategy • Small defects may be closed directly, but there is a high dehiscence rate following radiotherapy. • Skin-only defects can be closed with skin graft or small local flaps, e.g. rhomboid. • The following reconstructive strategy is illustrative rather than prescriptive. ∘ Most flaps are versatile and adaptable for various indications: – De-epithelialised fasciocutaneous flaps can be used for fistulas. – Vaginal reconstruction has been described using SGAP and IGAP flaps. Superficial defects • Example: vulvectomy. • Fasciocutaneous flaps, e.g. lotus petal, work well. The Trunk and Urogenital System 471 Complex small defects • Examples: fistulas, sinuses. • Following excision, gracilis can be interposed to prevent recurrence. Complex large defects • Examples: APR, pelvic exenteration. • Flap choice depends on whether radiation was given. ∘ No radiotherapy: local fasciocutaneous or myocutaneous flaps. ∘ After radiotherapy: non-irradiated tissue is imported, e.g. VRAM, ALT. Vaginal reconstruction • Partial defects: VRAM or one of the gluteal flaps. • Total defects: tubed VRAM, Singapore flaps or segment of colon. Hypospadias • Hypospadias is a congenital condition characterised by: 1 Abnormally proximal urethral meatus on the ventral aspect of the penis or scrotum. 2 Hooded, ventrally deficient, prepuce (foreskin). 3 Ventral curvature of the penis (chordee). – The term chordee means curvature, not ‘cords’ of tissue causing the curvature. – Chordee may therefore be corrected, but chordee cannot be excised. • The following abnormalities may also be present: ∘ Flattened glans penis ∘ Downward glans tilt ∘ Deviation of the midline penile raphe ∘ Scrotal encroachment onto the penile shaft ∘ Midline scrotal cleft ∘ Penoscrotal transposition. • ‘Megameatus intact prepuce’ (MIP) is a variant of hypospadias. ∘ MIP has a normal foreskin that conceals a glanular or distal shaft hypospadias. Epidemiology • Some degree of hypospadias affects approximately 1 in 300 live male births. • Associated abnormalities occur more frequently with proximal than distal hypospadias. • Approximately 10% of hypospadias cases are associated with inguinal hernias. ∘ Incidence of congenital inguinal hernia in the general population is 1–5%. • Approximately 20% are associated with other abnormalities of the genitourinary tract. ∘ The most common is cryptorchidism: affects 3% with distal hypospadias; 10% with proximal hypospadias. ∘ Other anomalies: asymptomatic paraurethral sinuses, urethral valves, enlarged prostatic utricle. – These may hinder placement of a urethral catheter. • 4–10% of boys with hypospadias have a positive family history, either maternal or paternal. 472 Chapter 7 • Hypospadias occurs five times more commonly after in vitro fertilisation (IVF). ∘ May be due to hormonal manipulation during IVF, or paternal subfertility. • Placental insufficiency is also implicated in hypospadias risk, which is associated with: ∘ Low birth weight (<10th centile) ∘ Preterm birth (<37 weeks) ∘ Maternal obesity, diabetes and hypertension. Aetiology • The underlying cause of non-syndromic hypospadias in most cases is unknown. • Presuming hypospadias is a form of developmental arrest, these factors are implicated: ∘ Defects of testosterone synthesis ∘ Androgen receptor deficiency ∘ Mutations in FGF8 and FGFR2 genes ∘ Increased levels of exogenous (environmental) oestrogens. Classification • Classified anatomically by the position of the urethral meatus: 1 Glanular 2 Subcoronal 3 Distal penile 4 Midshaft 5 Proximal penile 6 Penoscrotal 7 Scrotal 8 Perineal. • This is Duckett’s classification, designed to be applied after release of any ventral curvature. • Numbers 1–4 constitute ‘distal hypospadias’ (85% of cases). • The remainder are considered ‘proximal hypospadias’. Embryology Internal organs • Before the 6th gestational week, the embryo is sexually indeterminate. • During the 6th week, gonads arise from genital ridges and differentiate into their male and female forms. ∘ Occurs in response to the arrival of primordial germ cells from the yolk sac. • Internal sex organs form from the mesonephric and paramesonephric ducts: The mesonephric duct • Also known as the Wolffian duct. • Forms the majority of the male internal sex organs. • The sex-determining region of the Y chromosome (SRY) induces genital ridge cells to differentiate into Sertoli cells. • Sertoli cells secrete Müllerian-inhibiting factor. ∘ This causes the paramesonephric ducts to regress, between 8th and 10th weeks. The Trunk and Urogenital System 473 • SRY also induces genital ridge mesenchyme to differentiate into Leydig cells. • Leydig cells secrete testosterone, which stimulates development of: ∘ Mesonephric ducts ∘ Genital tubercle. • In the male, mesonephric ducts give rise to ‘SEED’: ∘ Seminal vesicles ∘ Epididymis ∘ Ejaculatory ducts ∘ Ductus (vas) deferens. The paramesonephric duct • Also known as the Müllerian duct. • In the absence of a Y chromosome and SRY, formation of Sertoli cells, Müllerian-inhibiting factor, Leydig cells and androgen production do not occur. • Without androgen stimulation, mesonephric ducts degenerate. • In the female, paramesonephric ducts persist and develop into: ∘ Fallopian tubes ∘ Uterus ∘ Cervix ∘ Upper vagina. – The lower vagina is initially occluded by a block of tissue – the vaginal plate. – This elongates during the 3rd–5th months and subsequently canalises to form the inferior vaginal lumen. • In the male, paramesonephric ducts degenerate into the appendix testis and prostatic utricle. External organs • Before the 11th gestational week, external genitalia are sexually indistinct. • At the 11th week, the external genitalia consist of: ∘ Central urethral groove (endoderm) ∘ Urethral folds either side of the urethral groove ∘ Labioscrotal swellings either side of the urethral folds ∘ Genital tubercle anteriorly. • Male or female differentiation depends upon androgen receptor signalling. In the male • The genital tubercle forms the penis. • The urethral groove grows distally down the genital tubercle. ∘ Does not quite extend to the tip of the penis. • Distal glanular urethra is formed by ectodermal ingrowth from the glans penis. ∘ Evidenced by stratified squamous epithelium in the fossa navicularis. • The urethral folds fuse over the urethral groove, forming a tubed urethra. ∘ Urethral folds fuse proximal-to-distal. • The embryonic penis initially exhibits a ventral curvature. ∘ Chordee may therefore be due to arrest of penis development at this stage. 474 Chapter 7 • Labioscrotal swellings fuse to form the scrotum. • Testes descend into the scrotum, with the aid of the gubernaculum, around the 7th month. In the female • The genital tubercle forms the clitoris. • The urethral groove does not extend into the genital tubercle. • Urethral folds do not fuse over the urethral groove. Instead, they form: ∘ Labia minora ∘ Prepuce of the clitoris. • Labioscrotal swellings become labia majora. Anatomy of the penis • The penis is composed of: ∘ The root proximally ∘ The body in its central portion ∘ The glans distally. • The dorsal surface of the penis is continuous with the anterior abdominal wall. ∘ It is therefore only ‘dorsal’ when the penis is erect. The root • Attached to the inferior surface of the perineal membrane. • Consists of: 1 Bulb of the penis centrally. – Continues as the corpus spongiosum in the body of the penis. – The bulb is penetrated by the spongy urethra and paired bulbourethral arteries. 2 Crura of the penis on each side of the bulb. – Each crus continues as a corpus cavernosum in the body of the penis. – Crura are attached to the ischiopubic rami. – The deep arteries of the penis enter each crus to run in the corpora cavernosa. 3 Bulbospongiosus and ischiocavernosus muscles. The body • Consists of: ∘ Two adjacent corpora cavernosa on the dorsal surface. ∘ A single corpus spongiosum on the ventral surface, containing the spongy urethra. • These three cylinders of tissue are enclosed by the tunica albuginea. • Superficial to tunica albuginea is the deep fascia of the penis (Buck’s fascia), which covers all three corpora. ∘ Buck’s fascia is continuous with deep muscle fascia at the root. ∘ Paired dorsal arteries of the penis, a dorsal vein and dorsal nerves are contained within Buck’s fascia. • Superficial to Buck’s fascia is skin and subcutaneous connective tissue. ∘ Over the penis and scrotum, subcutaneous connective tissue contains abundant smooth muscle fibres and is called dartos fascia. ∘ Dartos fascia is continuous with Colles’ fascia of the perineum. The Trunk and Urogenital System 475 Cross section of the penis Superficial dorsal vein Skin Subcutaneous tissue and dartos fascia Dorsal nerve and artery Deep dorsal vein Buck’s fascia Tunica albuginea Deep artery of the penis Corpus cavernosum Corpus spongiosum Urethra The glans • The distal part of the corpus spongiosum expands to form the conical glans penis. ∘ Glans is Latin for acorn. • The prominent proximal margin of the glans is called the corona. • The normal external urethral meatus is slit-shaped, not round. The urethra • Divided into three parts: 1 Prostatic urethra – Within the prostate gland. 2 Membranous urethra – Passes through the deep perineal pouch. – Pierces the perineal membrane to become the penile urethra. 3 Penile urethra – Also known as spongy urethra because it lies within the corpus spongiosum. Assessment of a child with hypospadias Important factors in the history • Ask the parents: ∘ If they have witnessed erections and whether they were straight. ∘ Direction and flow of the urinary stream – important for post-operative follow-up. Examination 1 Assess penis size. ∘ Pre-operative topical or intramuscular testosterone may be beneficial if the glans is very small (rare). 2 Check both testes have descended into the scrotum. ∘ Done bimanually, with one hand closing the deep inguinal ring while the other palpates for the testis, both in the inguinal canal and scrotum. ∘ This manoeuvre prevents the testis from migrating back into the abdomen. 476 Chapter 7 3 Exclude inguinal hernias. ∘ If the hernia is intermittent, a patent processus vaginalis may be palpable between finger and thumb – so-called ‘silk glove’ sign. 4 If possible, watch the child pass urine to assess: ∘ Direction of stream. ∘ Flow. • The foreskin is adherent to the glans in children. ∘ These adhesions should not be separated during clinical examination. • Parents should be told not to have the child circumcised. ∘ Preputial skin may be needed for reconstruction. Investigations • The majority of children require no further investigation. • Proximal hypospadias with cryptorchidism increases the likelihood of a disorder of sex development. ∘ Such patients should be referred for specialist assessment: – Pelvic ultrasound to evaluate internal genitalia – Karyotype analysis – Serum electrolytes as a screen for congenital adrenal hyperplasia. • Coexistence of hypospadias with other anomalies increases the likelihood of a syndrome. ∘ Such anomalies include developmental delay, abnormal facies, anorectal and scrotal malformations. ∘ Most are associated with proximal, rather than distal, hypospadias. ∘ These patients should, in addition, have ultrasound assessment of the upper urinary tract. Surgical correction Aims of surgery • Surgical correction of hypospadias should aim to produce: ∘ A normal aesthetic appearance, including a slit-like terminal meatus ∘ Normal erection and sexual function ∘ Normal urinary stream. Timing of surgery • Optimal timing is controversial and based on expert opinion: ∘ The tendency in North America is to operate between 6 and 12 months. ∘ The tendency in Europe is to operate between 12 and 18 months. Anaesthetic considerations • In appropriate centres of expertise, day surgery can be safely performed on healthy boys from a gestational age of 50 weeks. • Snodgrass operates at 3 months in these circumstances. The Trunk and Urogenital System 477 Psychological considerations • 18–36 months of age has been anecdotally labelled a ‘difficult period’ for hospitalisation. ∘ This long-held view is based on outdated practices where children were segregated from families. • There is some evidence that surgery between 3 and 5 years increases anxiety for physical injury. • Other evidence shows no difference in quality-of-life assessment related to patient age at operation. Technical considerations • Some patients, particularly with proximal hypospadias, have a small glans. • This makes repair technically more difficult and may require more complex reconstruction. • Some recommend delaying operating until the penis grows or until any hormonal treatments have had time to take effect. Post-operative urinary diversion • Urethral catheters extend into the bladder. • Urethral stents do not extend beyond the external sphincter of the bladder. • There is no clear guidance on whether catheterisation or stenting is necessary. • Most studies show no difference in complications whether diversion was used or not. • Incidence of dysuria, urinary retention and urinary extravasation is higher without diversion. • Many catheterise or stent intraoperatively to avoid having to insert one acutely for postoperative urinary retention. • Catheters can cause bladder spasm and urinary tract infections. • Stents avoid problems with bladder spasm, but are more easily dislodged. Surgical techniques • Hundreds of urethroplasty techniques have been described. • They can be summarised into three core procedures: 1 Tubularisation of the urethral plate. 2 Supplementation or replacement of the urethral plate with skin flaps. 3 Replacement of the urethral plate with grafts. • Any ventral curvature is addressed before completing the urethroplasty. Correction of ventral curvature • Chordee was originally attributed to fibrous bands of tissue, or a scarred distal urethral plate. ∘ However, histological examination of resected urethral plates shows vascularised tissue without fibrosis. ∘ The urethral plate is now preserved where possible. 478 Chapter 7 • It is not possible to determine pre-operatively whether ventral curvature is true chordee or simply soft tissue tethering due to deficient ventral skin. ∘ The first stage of primary hypospadias repair is therefore degloving of the penile skin. ∘ Apparent bending may improve or completely resolve as the skin is degloved. • Severity of chordee is then assessed by inducing an artificial erection – Horton’s test: 1 Place a tourniquet around the base of the penis. 2 Inject sterile saline into one corpus cavernosum. • If there is no chordee, urethroplasty is done. • If ventral curvature persists, i.e. true chordee, the following can be done: Ventral curvature <30∘ • Corrected by midline dorsal plication of the tunica albuginea. ∘ Also known as a Nesbit dorsal tunical tuck. • One or two 4-0 or 5-0 permanent sutures placed opposite the area of the greatest bending is usually sufficient. • Nesbit described the procedure both with and without excision of an ellipse of tunica. Ventral curvature >30∘ • Usually corrected using some form of ventral lengthening procedure. • Traditionally, it involves a transverse incision through the urethral plate. • Rarely, the underlying tunica albuginea is also incised to achieve full correction. • The resulting defect is usually covered using skin grafts or local flaps. ∘ Intestinal grafts or segments of vein have been described, but rarely used. • An alternative that preserves the urethral plate and corpus spongiosum is to dissect these structures from the underlying corpora cavernosa. ∘ This may correct chordee, if not, traditional corporotomy and graft is done. ∘ It may be possible to avoid a graft by making multiple transverse tunical incisions without exposing the erectile corpora cavernosa tissue. • If chordee persists, the urethral plate is divided as a last resort. Urethroplasty for distal hypospadias • The most common method of repair is the tubularised incised plate (TIP). • Others include the meatal advancement and glanuloplasty incorporated (MAGPI), Mathieu flip-flap, urethral advancement and onlay preputial flaps. • The choice of repair is largely dictated by surgeon preference. TIP • Also known as the Snodgrass repair. ∘ Simple tubularisation was first described by Thiersch (1869) and Duplay (1880). ∘ Urethral plate incision was described by Rich et al. (1989). ∘ Snodgrass (1994) described a combination of these techniques. 1 Midline longitudinal incision through the urethral plate. ∘ This widens a narrow plate and converts a flat surface into a deep groove that will tubularise to form a slit-like meatus. ∘ The incision re-epithelialises spontaneously during the healing period. The Trunk and Urogenital System 479 2 Lateral edges of the urethral plate are incised into corpus spongiosum and glans, to allow the edges to be brought over a catheter to form a tube. 3 Suturing of the tube begins distally, 3 mm proximal to the end of the urethral plate. ∘ Ensures an oval meatus and avoids later meatal stenosis. ∘ A double layer of urethral sutures is preferred. 4 A dartos flap can be raised from the skin of the prepuce or shaft. ∘ Forms an additional ‘waterproofing’ layer over the urethral suture line. 5 Glans wings are sutured together over the dartos flap to fashion an aesthetic glans. Meatal advancement and glanuloplasty • Known as the MAGPI repair. • Also known as the Duckett operation, after it was described by him (1981). • Suitable for cases that have a very distal and mobile meatus with no chordee. 1 A longitudinal incision is made between the meatus and its intended position. 2 The longitudinal incision is sutured transversely, in Heineke-Mikulicz fashion. 3 Advancement of the glans bilaterally around the urethra. The Mathieu perimeatal-based flap technique • Also known as the ‘flip-flap’. 1 A distally-based skin flap is designed with its base just proximal to the meatus. 2 The flap is flipped to create the superficial part of the circumference of the urethra. 3 The flap is sutured to the edges of the urethral plate to form a tubed urethra. 4 The glans is approximated around the neourethra. Urethral advancement • Involves circumferential dissection and advancement of the distal urethra. • Extreme mobilisation of the urethra to the bulb can gain 2.5 cm of urethral length in children. • Also known as bulbar elongation and anastomotic meatoplasty (BEAM). • Requires a separate perineal incision to fully mobilise the bulbar urethra. ∘ Full mobilisation is essential to avoid excessive tension on the advanced urethra, which would cause ventral curvature. • The dissected urethra is advanced until its end lies at the level of a normal meatus. Onlay preputial flap • The superficial part of the urethral circumference is reconstructed with a patch of skin from the inner aspect of the prepuce. • Useful for midshaft hypospadias. 1 The flap is pedicled on subcutaneous tissue. 2 It can then be transposed around the penile shaft and sutured to the edges of the urethral plate to form a tubed urethra. 3 The pedicle, consisting of dartos fascia, can be used as a waterproofing layer. Urethroplasty for proximal hypospadias • This is a controversial topic. 480 Chapter 7 • Options for repair depend upon whether the urethral plate is intact following the release of chordee. • If the urethral plate is preserved: ∘ TIP ∘ Onlay preputial flap. • If the urethral plate is transected or excised: ∘ Tubularised preputial flap ∘ Two-stage repair. TIP • Similar to that used for distal hypospadias, except: 1 Beware not to create two strips when incising a completely mobilised urethral plate. 2 The divergent corpus spongiosum is sutured over the neourethra. 3 Either a tunica vaginalis flap or dartos flap can be used for waterproofing. ∘ Tunica vaginalis is dissected off the testis as far as the superficial inguinal ring. Tubularised preputial flap • Similar in principle to the onlay preputial flap. • However, a wider and longer flap allows complete tubularisation prior to inset. Two-stage repair • In general, single-stage repairs are preferred whenever possible. • Two-stage repair is considered for: ∘ Scrotal or perineal hypospadias ∘ Severe ventral curvature ∘ Small penis. • Principles of two-stage repair: 1 Correction of ventral curvature, which may involve division of the urethral plate. 2 Widening the urethral plate by incising it longitudinally. 3 Resurfacing this incised raw area with tissue to be used for neourethra formation at a second stage. – Full-thickness skin graft from the inner prepuce is commonly used. • Described by Cloutier (1962); subsequently popularised by Bracka. – Other graft donor sites include buccal mucosa and bladder mucosa. – Alternatively, use a vascularised preputial flap, described by Bretteville. 4 The second stage is usually performed 4–6 months later, depending on tissue quality. – The resurfaced area is incised as a 10–15 mm wide U shape, to allow tubularisation. Complications of hypospadias surgery • Overall complication rates vary according to the technique used, proximal versus distal hypospadias and surgeon’s experience: ∘ 10% following distal TIP repair ∘ 20% following proximal TIP repair The Trunk and Urogenital System ∘ ∘ 481 25% following preputial flap techniques 15% following two-stage repairs. Early complications • Bladder spasm • Haematoma • Wound dehiscence • Oedema • Erections can cause complications ∘ These can be suppressed with cyproterone acetate, an anti-androgen. Late complications • Fistula ∘ Most common complication of hypospadias repair. • Urethral stenosis ∘ May indicate technical error, ischaemia or balanitis xerotica obliterans (BXO). ∘ Most common site of stricture is at the proximal anastomosis site. • Diverticulum ∘ Occurs due to distal obstruction or turbulent urinary flow. ∘ Characterised by the ballooning of the neourethra during voiding, with post-void dribbling. • Persistent urinary tract infections ∘ May occur if hair-bearing skin is used to reconstruct the urethra. Balanitis xerotica obliterans (BXO) Also known as lichen sclerosus et atrophicus. BXO is a premalignant lesion, associated with SCC in adults. May present with late development of meatal stenosis or neourethral stricture. It has a characteristic white appearance. Treatment is by radical excision of the affected skin. The defect can be reconstructed with mucosal grafts from either the mouth or bladder. ∘ Inner preputial skin grafts are prone to develop recurrent BXO. • Topical treatment with steroid or tacrolimus may not be appropriate in hypospadias because the urethra, not just the glans, is likely to be involved. • • • • • • Bladder exstrophy-epispadias complex Background • The exstrophy-epispadias complex is a congenital condition characterised by abnormal development of: ∘ Dorsal surface of the penis ∘ Abdominal wall 482 Chapter 7 ∘ ∘ • • • • Pelvic bones Anterior wall of bladder. Exstrophy is derived from Greek, meaning ‘to turn inside-out’. Thought to be due to the failure of mesenchymal penetration. Bladder exstrophy combined with complete epispadias is the most common deformity. ∘ Occurs once every 30,000 births. 3–4× commoner in males. Diagnosis and correction • Clinical features vary from mild to major: ∘ Epispadias – Characterised by a urethra that opens onto the dorsal penis. – Cleft clitoris and widely divergent labia occur in the female. • Epispadias is repaired with similar techniques as for hypospadias. ∘ Diastasis of RA. ∘ Diastasis of pubic rami with an open pelvic ring. – The pelvis can be closed with osteotomies. ∘ Bladder exstrophy. – The anterior wall of the bladder may be absent. – Bladder eversion may occur. • Corrected by dissecting the bladder plate off the anterior abdominal wall. • The lateral edges are sutured to each other to recreate the bladder cavity. Ambiguous genitalia Classification • Causes of ambiguous genitalia can be classified as: ∘ Masculinised female ∘ Undermasculinised male ∘ Disorders of gonadal differentiation ∘ True hermaphroditism. Masculinised female Congenital adrenocortical hyperplasia • Most common cause of ambiguous genitalia. • Also known as female pseudo-hermaphroditism or adrenogenital syndrome. • Patients are genetically female (46XX). • There is usually a deficiency in the enzyme 21-hydroxylase. ∘ One of the terminal enzymes of glucocorticoid synthesis. ∘ Absence causes build-up of steroid hormone intermediates that are diverted to the testosterone synthetic pathway. The Trunk and Urogenital System 483 ∘ • • • • 75% have aldosterone deficiency, leading to salt wasting. – Can present acutely with profound dehydration and adrenal crisis. External genitalia vary from mildly enlarged clitoris to normal penis with terminal meatus. These children should be raised as female and are usually fertile. Medical treatment involves life-long hydrocortisone or fludrocortisone. Surgical correction may be necessary to feminise external genitalia. ∘ Usually performed between 3 and 6 months, and may include: – Clitoral recession – Vaginoplasty. Undermasculinised male • Patients are genetically male (46XY). • They have inadequate masculinisation of external genitalia, due to: ∘ Leydig cell aplasia. ∘ Deficiency of any of the five enzymes required for testosterone synthesis. ∘ Deficiency of 5-α reductase, which normally converts testosterone to its more active form, dihydrotestosterone. ∘ Androgen insensitivity syndrome, resulting in female external genitalia. • These children should be raised as female as they would always have an inadequate phallus with likely androgen resistance of brain tissue. • Surgery involves: ∘ Orchidectomy – Some believe it is best to delay orchidectomy until after puberty. • Testes produce estradiol that results in the feminine changes of puberty. ∘ Vaginal dilatation. Disorders of gonadal differentiation Mixed gonadal dysgenesis • Second most common cause of ambiguous genitalia. • The testis on one side develops normally, albeit often intra-abdominal. • The other testis does not develop, known as a ‘streak gonad’. • Most affected children have a 46XY or 45XO karyotype. • The normal testis has high incidence of developing gonadoblastoma. • Patients should also be screened for Wilms’ tumour. • These children should be raised as female, because the phallus is usually underdeveloped but uterus, vagina and fallopian tube are present. • Surgery involves: ∘ Resection of any Y chromosomal material, e.g. the residual testis. ∘ Clitoral recession and vaginoplasty. Klinefelter’s syndrome • Males with this syndrome have a 47XXY karyotype. 484 Chapter 7 • Testes are small and firm; serum testosterone is low-normal. ∘ Leads to a more female phenotype: – Gynaecoid fat distribution – Gynaecomastia – Lack of facial hair. True hermaphroditism • Very rare. • Most patients are 46XX, and may have: ∘ An ovary on one side, and a testis on the other, or ∘ Bilateral ovotestes. • 75% are raised as male because the external genitalia are masculinised. • Sex assignment should be based on the functional potential of the genitalia. ∘ Patients raised as female who have appropriate internal genitalia have potential for fertility. – Surgery involves removal of testicular tissue. Patient assessment • Evaluation and initial management of a neonate with ambiguous genitalia should be treated as a medical and psychosocial emergency. • Tact and sensitivity are required when dealing with the family. • Aim to make a precise diagnosis of the underlying condition. ∘ This guides gender assignment, with the involvement of parents. • A full assessment is carried out by an MDT of a geneticist, specialist paediatric urologist and/or plastic surgeon, paediatrician and psychologist. History • Important features: ∘ Previous sudden infant death of a sibling. – May suggest congenital adrenal hyperplasia. ∘ Family history of infertility, amenorrhoea or hirsutism. ∘ Maternal use of steroids or contraceptives during pregnancy. Examination • The finding of one or two palpable gonads rules out masculinisation of the female. • Bilateral impalpable testes, or unilateral impalpable testis with hypospadias, strongly suggests some form of disorder of sexual development. • Measure stretched penile length – average for a term neonate is 3.5 cm. • A penis usually has a single midline frenulum. • A clitoris usually has two paramedian frenula. Investigations • Pelvic and abdominal ultrasound to identify the gonads and uterus. The Trunk and Urogenital System 485 • Full karyotype – usually takes 2 days. ∘ A quicker gross chromosomal evaluation is had with fluorescence in situ hybridisation (FISH) targeted at X and Y chromosomes. • Neonatal blood tests can rule out congenital adrenal hyperplasia and assay testosterone/ dihydrotestosterone levels. • If the diagnosis remains uncertain, laparoscopy with gonadal biopsy is required. Gender assignment • Done after the diagnosis is confirmed and discussed in detail with the family. • Meyer-Bahlburg sets out an ‘optimal gender policy’ based on: ∘ Reproductive potential, if attainable ∘ Good sexual function ∘ Minimal medical procedures ∘ Overall gender-appropriate appearance ∘ Stable gender identity ∘ Psychosocial well-being. • In general, a 46XX karyotype masculinised female is assigned a female gender. • Assignment of a 46XY karyotype takes into account penile length and evidence of androgen insensitivity. Vaginal agenesis Background • Rare; affects between 1 in 4000 and 1 in 10,000 female births. • Most common cause is Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome. ∘ This is congenital absence of uterus and vagina with a normal female genotype, normal secondary sexual characteristics and normal ovaries. ∘ Results from failure of paramesonephric duct development. ∘ 30% associated with abnormalities of the upper urinary tract: – Renal agenesis – Pelvic kidney – Horseshoe kidney. ∘ Patients should therefore be investigated with ultrasound or MRI. • There is sometimes a vestigial vaginal dimple. • Amenorrhoea is the presenting symptom if there is no uterus. • Cases of vaginal agenesis with a normal uterus may present with haematocolpos. Reconstruction • Patients usually present during puberty due to amenorrhoea. ∘ Treatment should be deferred until adolescence to allow informed consent and compliance with any post-operative dilatation. • Techniques used to reconstruct the vagina include: 486 Chapter 7 Dilatation • Non-operative technique, described by Frank (1938). • Effective dilatation requires the presence of a vaginal dimple. • The vagina is sequentially expanded with glass or plastic moulds. • Dilatation is widely considered first line treatment because success rates are high and risks are low. Reconstruction with a split-skin graft • Split-skin graft placed over a mould was popularised by McIndoe. • The mould is inserted and labia minora oversewn. • The mould is left in situ for 6 months. • Regular dilatation is required to prevent subsequent stenosis. Alternative techniques • These are analogous to those described for acquired perineal defects: ∘ Segment of colon ∘ Regional flaps, e.g. pudendal-thigh flaps, gracilis. Penile reconstruction Background • Reconstruction of the penis is indicated for: ∘ Congenital – Genital ambiguity – Gender dysphoria in female-to-male transexuals. ∘ Acquired – Traumatic amputation – Oncological amputation – Infection. Surgical reconstruction • Technique of choice largely depends on the indication for surgery. • The aims of surgery are: 1 Create a neourethra to allow urination while standing. 2 Provide tactile and erogenous sensibility. 3 Allow insertion of a prosthetic stiffener if required. 4 Aesthetically acceptable result to the patient. Ambiguous genitalia • Options to make the penis more prominent for patients with a small but complete micropenis: ∘ Mobilising corpora cavernosa from pubic rami ∘ Accentuating the penoscrotal angle ∘ Reducing pubic fat. The Trunk and Urogenital System 487 Metaidoioplasty • Used in female-to-male transexuals. • Surgery normally follows hormonal treatment to overdevelop the clitoris. • Elongation and displacement of the clitoris constructs a microphallus. • The urethra is lengthened to the tip of the phallus using an anterior musculomucosal vaginal flap. • Advantages: ∘ Maintains erogenous sensitivity. ∘ Avoids extensive scarring associated with more complex techniques. • Disadvantages: ∘ Creates a very short phallus that will not usually allow sexual intercourse. ∘ 50% of patients will not be able to void while standing. Total penile reconstruction • Flaps described include tube pedicled flaps and pedicled gracilis flaps. • Most common methods use forearm flaps. Free radial forearm flap (Chinese method) • First described by Chang and Hwang (1984). • The skin paddle design is subject to many modifications. • Plan to create a ‘tube within a tube’ to allow formation of the urethra. ∘ The neourethra is usually tubed from ulnar skin, which is less hairy. • A piece of radius or segment of costal cartilage can be incorporated for rigidity. • Lateral and medial antebrachial cutaneous nerves can also be included. ∘ These are coapted to the dorsal nerves of the penis (or clitoris). – If unavailable, an interposition nerve graft will reach a pudendal nerve. • The flap must have protective sensation prior to the use of prosthetic stiffeners. • The flap is usually revascularised using the deep inferior epigastric vessels. • The greatest disadvantage of forearm flaps is the prominent donor site. Alternative techniques • Free sensate osteocutaneous fibula flap. ∘ This can be prelaminated with a tubed skin graft to form a neourethra. • Free scapular flap. • Infra-umbilical flap. Replantation • As with finger replantation, sharp nonavulsive injuries do better. • A spatulated urethral repair is first performed over a urethral catheter, which provides a stable platform for the remaining repairs: ∘ Microsurgical anastomosis of the two dorsal arteries and single dorsal vein. ∘ Coaptation of the paired dorsal nerves. ∘ Repair of the tunica albuginea of the corpora cavernosa. 488 Chapter 7 Further reading Abdominal wall reconstruction Björck M, Bruhin A, Cheatham M et al. Classification–important step to improve management of patients with an open abdomen. World J Surg 2009;33(6):1154–7. Iida T, Mihara M, Narushima M et al. Dynamic reconstruction of full-thickness abdominal wall defects using free innervated vastus lateralis muscle flap combined with free anterolateral thigh flap. Ann Plast Surg 2013;70(3):331–4. Janis JE, O’Neill AC, Ahmad J et al. Acellular dermal matrices in abdominal wall reconstruction: a systematic review of the current evidence. Plast Reconstr Surg 2012;130(5 Suppl 2):183S-93S. Southwell-Keely JP, Berry MG. Umbilical reconstruction: a review of techniques. J Plast Reconstr Aesthet Surg 2011;64(6):803–8. Ramirez OM, Ruas E, Dellon AL. “Components separation” method for closure of abdominal-wall defects: an anatomic and clinical study. Plast Reconstr Surg 1990;86(3):519–26. Perineal reconstruction Boccola MA, Rozen WM, Ek EW et al. Inferior gluteal artery myocutaneous island transposition flap reconstruction of irradiated perineal defects. J Plast Reconstr Aesthet Surg 2010;63(7):1169–75. Nisar PJ, Scott HJ. Myocutaneous flap reconstruction of the pelvis after abdominoperineal excision. Colorectal Dis 2009;11(8):806–16. Sinna R, Qassemyar Q, Benhaim T et al. Perforator flaps: a new option in perineal reconstruction. J Plast Reconstr Aesthet Surg 2010;63(11):e766–74. Wee JT, Joseph VT. A new technique of vaginal reconstruction using neurovascular pudendal-thigh flaps: a preliminary report. Plast Reconstr Surg 1989;83(4):701–9. Yii NW, Niranjan NS. Lotus petal flaps in vulvo-vaginal reconstruction. Br J Plast Surg 1996;49(8):547–54. Hypospadias Bracka A. A versatile two-stage hypospadias repair. Br J Plast Surg 1995;48(6):345–52. Duckett JW, Snyder HM 3rd., Meatal advancement and glanuloplasty hypospadias repair after 1,000 cases: avoidance of meatal stenosis and regression. J Urol 1992;147(3):665–9. Moir GC, Stevenson JH. A modified Bretteville technique for hypospadias. Br J Plast Surg 1996;49(4):223–7. Snodgrass W. Tubularized, incised plate urethroplasty for distal hypospadias. J Urol 1994;151(2):464–5. Springer A, Krois W, Horcher E. Trends in hypospadias surgery: results of a worldwide survey. Eur Urol 2011;60(6):1184–9. Warwick RT, Parkhouse H, Chapple CR. Bulbar elongation anastomotic meatoplasty (BEAM) for subterminal and hypospadiac urethroplasty. J Urol 1997;158(3 Pt 2):1160–7. Ambiguous genitalia Meyer-Bahlburg HF. Gender assignment and reassignment in 46, XY pseudohermaphroditism and related conditions. J Clin Endocrinol Metab 1999;84(10):3455–8. Newman K, Randolph J, Anderson K. The surgical management of infants and children with ambiguous genitalia: lessons learned from 25 years. Ann Surg 1992;215(6):644–53. The Trunk and Urogenital System 489 Vaginal agenesis McIndoe A. The treatment of congenital absence and obliterative conditions of the vagina. Br J Plast Surg 1950; 2(4):254–67. Penile reconstruction Garaffa G, Raheem AA, Ralph DJ. An update on penile reconstruction. Asian J Androl 2011;13(3):391–4. CHAPTER 8 Burns CHAPTER CONTENTS Introduction, 490 Thermal burns, 491 Burn reconstruction, 516 Chemical burns, 521 Electrical burns, 523 Cold injury, 525 Conditions causing burn-like wounds, 526 Further reading, 528 Introduction • A burn is defined as coagulative destruction of the surface layers of the body. • 250,000 burn injuries occur in the United Kingdom and 2.5 million in the United States every year. ∘ Most are preventable. • Every year, 300 people die in hospital following burns in the United Kingdom; 3500 in the United States. • Mortality after a 50% total body surface area (TBSA) burn in a young adult has reduced from 50%, 25 years ago, to 10% with modern management. • Ten years ago, an 80–90% TBSA burn had a 10% chance of survival. ∘ This has improved to >50% survival. • Improvements are attributed to advancements in: ∘ Resuscitation ∘ Surgical techniques ∘ Management of sepsis ∘ Nutritional and metabolic support. Classification Aetiology • • • • • Thermal Chemical Electrical Cold injury Radiation. Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 490 Burns 491 Depth • Superficial (epidermal only) • Superficial dermal • Deep dermal • Full thickness. Body surface area involved • Burns >15% TBSA in adults or >10% in children require formal resuscitation. Thermal burns • Most burns are thermal injuries, caused by: ∘ Scalding by hot liquids or gases ∘ Contact ∘ Flame ∘ Flash. • Thermal burns tend to occur in: ∘ The young ∘ The old ∘ The unlucky. • Survival is largely determined by the burn’s TBSA and depth, and patient’s age. • Other factors determining survivability: ∘ Inhalation injury ∘ Medical conditions that limit cardiovascular and respiratory reserve ∘ Coexisting polytrauma. Pathophysiology of thermal burn injury • The degree of tissue necrosis depends on the temperature and duration of application of the burning agent. • Boiling water causes partial thickness burn in 0.1 seconds; full thickness burn in 1 second. • Prolonged contact with water or radiator at 50 ∘ C can cause deep burns in the obtunded. Local effects Jackson’s burn wound model describes three zones of injury: 1 Inner zone of coagulation (coagulative necrosis) ∘ Cell death and coagulation of cellular proteins. 2 Intermediate zone of stasis ∘ Damage to microcirculation causing ischaemia which, untreated, proceeds to necrosis. ∘ The extent of progression is influenced by effective resuscitation. 3 Outer zone of hyperaemia ∘ Cellular damage triggers release of inflammatory mediators. ∘ Inflammatory mediators are released from: – Capillary wall – White blood cells – Platelets. 492 ∘ ∘ ∘ Chapter 8 Examples: histamine, catecholamines, free oxygen radicals, platelet activating factor, arachidonic acid breakdown products. These result in vasodilatation and increased vessel permeability. Leads to fluid loss from the circulation into the interstitial space. Systemic effects • Systemic effects occur if >25–30% TBSA is burned. ∘ Conceptually, this is the zone of hyperaemia, which is so extensive that it involves the whole body. ∘ Mediated by overspill of local inflammatory mediators into the systemic circulation. – Examples: TNF, interleukins and interferon. • Early excision and closure of the burn wound limits systemic inflammation. • The systemic effects of a burn impact on all organ systems: ∘ Hypovolaemia ∘ Myocardial depression ∘ Pulmonary oedema ∘ Renal impairment ∘ Hepatic dysfunction ∘ Catabolism with increased metabolic rate ∘ Immunosuppression ∘ Loss of the protective function of the gut ∘ Psychological effects. Burn assessment Initial management • Burn is trauma; should be approached in an ATLS-style. • Airway may have sustained inhalation injury. ∘ Intubation required if airway patency is at risk or oedema expected. ∘ The tube is left uncut in case of subsequent facial swelling. • Profound hypovolaemia is not caused by acute burns – other causes of shock should be sought. • The cutaneous burn is considered after the secondary survey is underway and immediate life-threatening injuries have been dealt with. • Exposure allows the TBSA of burn to be estimated and guide initial fluid resuscitation. • Two large-bore IV cannulas inserted (through burnt skin if necessary); blood sent for baseline investigations. • Analgesia and fluid resuscitation. • Urinary catheter to assess adequacy of fluid resuscitation. • Nasogastric tube to decompress the stomach. ∘ Also used to start early feeding to provide nutrition and gut protection. • The wound is dressed, often with cling film in the first instance: ∘ Decreases evaporative fluid loss ∘ Allows reassessment without removal of dressing ∘ Helps pain relief. Burns 493 History • An ‘AMPLE’ history is taken if possible. ∘ Helps predict likelihood of inhalation injury, depth of burn, probability of other injuries. • Aim to establish the following facts: ∘ Mechanism of injury (what happened, where, when, how and why) ∘ Loss of consciousness ∘ What first aid was given and for how long ∘ What treatment received so far ∘ Tetanus status. • Regarding scalds: ∘ How recently had the kettle boiled? ∘ Was cold milk added to the tea/coffee? ∘ What was in the saucepan? – Soups, oil, vegetables or rice boil at higher temperatures than water. • Regarding electrical injuries: ∘ Voltage – domestic or industrial ∘ Associated flash ∘ Associated clothing fire. • Regarding chemical injuries: ∘ What chemical ∘ Length of time exposed to the chemical ∘ Specific antidotes used. Estimating burn depth • Burns are assessed clinically by their appearance. • Blisters are de-roofed to assess the base of the wound. Depth Appearance Superficial Red, like sunburn Superficial dermal Pink and moist Deep dermal Mottled white and ‘cherry red’ fixed staining Full thickness Leathery white/yellow Blanching Sensation Blisters Healing ✓ ✓ ✗ Painful Painful Dull ✗ ✓ ✗ ✓ ✓ ✗ ✗ None ✗ ✗ • Some use Laser Doppler Imaging to estimate blood flow within the wound, which correlates with burn depth. Estimating the surface area of a burn • Erythema should not be included. ∘ Erythema fades within hours – accurate burn estimation is a dynamic process. Comparison with the palm of the hand • A patient’s palm with fingers adducted is ≈0.8% TBSA. 494 Chapter 8 • Using a template of the patient’s hand is good for small, patchy burns. • Also good for very large burns – TBSA of unburnt skin is subtracted from 100%. The Wallace rule of nines • Adult body surface area (BSA): ∘ 9% head and neck ∘ 9% each arm ∘ 18% anterior trunk ∘ 18% posterior trunk ∘ 18% each leg ∘ 1% perineum. • BSA of children up to 1 year old is distributed differently: ∘ 18% head and neck ∘ 9% each arm ∘ 18% anterior trunk ∘ 18% posterior trunk ∘ 13.5% each leg ∘ 1% perineum. – For each additional year of age up to age 10, 1% should be subtracted from the head and neck and 0.5% added to each leg. Lund and Browder charts • Most accurate graphical record of the extent of the burn. • Automatically account for variation in body shape with age. ∘ Can therefore be used for both adults and children. Surgical decompression • Deep dermal and full thickness burns are inelastic. ∘ Can cause distal limb ischaemia if circumferential. • Similarly, extensive involvement of the chest (or abdomen in a child) can impair ventilation. • Constriction becomes worse once fluid resuscitation is begun. • Escharotomy relieves this constriction. ∘ Usually done with electrocautery, because they tend to bleed. • Fasciotomies usually required only for burns involving muscle, or high-voltage electrical injuries. • Escharotomies begin and end in unburnt or superficially burnt skin. • Limb escharotomies are generally made in midaxial lines. ∘ Avoid the ulnar nerve at the elbow and common peroneal nerve at the knee. • Chest escharotomies are made along the mid-axillary lines to the subcostal region. ∘ They are joined across the upper abdomen by a chevron incision parallel to the costal margin. ∘ This creates a mobile breastplate that moves with ventilation. ∘ The anaesthetist can advise on the adequacy of chest escharotomy by a drop in ventilator airway pressures. Burns 495 Inhalation injury • Patients with possible inhalation injury should be reviewed by an anaesthetist prior to transfer to a burns unit. • Prophylactic steroids or antibiotics are not indicated. Diagnosis • Inhalation injury is a clinical diagnosis. • Chest X-ray and arterial blood gas analysis may initially be normal. • Carboxyhaemoglobin levels are useful, but may be normal if patients receive oxygen during transfer to hospital. • Fibre-optic bronchoscopy is most reliable for making the diagnosis. • Characteristic bronchoscopic findings: ∘ Soot below the vocal cords ∘ Hyperaemia ∘ Mucosal oedema and ulceration. Factors suggestive of inhalation injury • History of inhaled hot gases and vapours given off by a fire: ∘ Fire in an enclosed space ∘ Patients found unconscious in a fire. • Symptoms ∘ Hoarse or weak voice ∘ Brassy cough ∘ Restlessness ∘ Shortness of breath • Signs ∘ Soot around the mouth and nose ∘ Singed facial and nasal hair ∘ Deep burns to face, neck and upper body ∘ Carbonaceous sputum or carbon deposits in the mouth and oropharynx ∘ Swollen upper airway ∘ Stridor ∘ Dyspnoea ∘ Hypoxia ∘ Pulmonary oedema. Classification of inhalation injury Supraglottic • Caused by heat. • If suspected, the airway must be secured before swelling develops in the ensuing hours. • Oedema usually resolves spontaneously within 3–5 days. Subglottic • Caused by products of combustion. 496 Chapter 8 • Act as direct irritants to the lungs, leading to bronchospasm, inflammation and bronchorrhoea. • Secretions tend to pool due to the dysfunction of the mucociliary elevator, leading to atelectasis, adult respiratory distress syndrome (ARDS) and secondary pneumonia. • Other changes: ∘ Ventilation-perfusion mismatching ∘ Decreased lung compliance ∘ Increased airways resistance. • Respiratory failure is common, requiring support in the form of: ∘ Humidified oxygen ∘ Nebulisers – Heparin to prevent cast formation – Acetylcysteine, a mucolytic – Salbutamol, a bronchodilator ∘ Chest physiotherapy ∘ Non-invasive ventilation with positive end-expiratory pressure (PEEP) ∘ Intubation and ventilation for bronchial lavage with dilute sodium bicarbonate. Systemic • Results from inhalation of carbon monoxide (CO) or cyanide from the fire. • Patients may require respiratory support. Carbon monoxide poisoning • CO has 250 times the affinity for deoxyhaemoglobin as oxygen. ∘ Half life of CO in patients breathing room air is ≈250 minutes. ∘ Half life of CO in patients breathing 100% oxygen is ≈40 minutes. • CO binds to intracellular cytochrome proteins, affecting mitochondria. ∘ Levels up to 10% may be found in smokers or truck drivers. ∘ 15–20% cause headache and confusion. ∘ 20–40% cause hallucinations and ataxia. ∘ CO levels of 60% are fatal. • Arterial blood gas analysis shows elevated carboxyhaemoglobin and metabolic acidosis. • Pulse oximetry cannot differentiate between oxy- and carboxyhaemoglobin. Treatment • CO poisoning is treated with 100% oxygen, delivered through a non-rebreathing facemask with a reservoir. • Patients with levels >25–30% should be ventilated. • It important to continue oxygen until the metabolic acidosis has cleared. ∘ Later secondary release of CO occurs from the cytochrome system. • Persistent metabolic acidosis may be due to poisoning by, e.g. cyanide. Tracheostomy • There is no consensus on tracheostomy use in burn patients. Burns 497 • Often used in patients with large burns and inhalation injury. ∘ They typically require repeated surgeries and prolonged ventilation. • Benefits of tracheostomy in inhalation injury: ∘ Ease of access to the bronchopulmonary tree for toileting and lavage. ∘ Improved ventilator weaning by reducing: – Dead space (10–50% less than endotracheal tube) – Airway resistance – Work of breathing – Sedation requirements. • Complications of tracheostomy: ∘ Bleeding from the wound or erosion of brachiocephalic vessels ∘ Accidental decannulation ∘ Swallowing dysfunction ∘ Tracheal ulceration and granulation tissue ∘ Tracheo-oesophageal fistula ∘ Tracheal stenosis. Complications of inhalation injury 1 Complications of mechanical ventilation ∘ Barotrauma and pneumothorax result from high ventilatory pressures required to overcome poor lung compliance and increased airways resistance seen in ARDS. ∘ This can be avoided by employing lung protective ventilation strategies: – Pressure controlled ventilation – High ventilation rate – Small tidal volumes – Inverse ratio ventilation – Physiological PEEP (approximately 5 cm H2 O) – Lower target oxygen saturation of 92% – Permissive hypercapnia and respiratory acidosis. ∘ High-frequency oscillatory ventilation can be used as a rescue strategy when conventional ventilation fails. 2 Complications of long-term intubation or tracheostomy ∘ Tracheomalacia ∘ Tracheal stenosis. 3 Complications of persistent inflammation ∘ ARDS ∘ Multiple organ dysfunction syndrome (MODS) ∘ In the long-term, fibrosis can lead to emphysema and bronchiectasis. Fluid resuscitation • Greatest fluid losses occur in the first 24 hours post-burn. • Increased vascular permeability allows leak of fluid and proteins from the intravascular to the interstitial compartment. • The rate of leakage peaks around 8–12 hours post-burn. 498 Chapter 8 • Burn shock results from this fluid shift, coupled with myocardial depression. • The goals of fluid resuscitation are: 1 Restore circulating volume 2 Preserve tissue perfusion 3 Avoid ischaemic extension of the burn wound. • Achieved by administering large volumes of salt-containing fluid. • Major burns present a ‘Catch 22’ situation: ∘ Burn oedema drives burn shock, but fluid resuscitation (required to treat burn shock) drives burn oedema. • Fluid resuscitation is required for: ∘ Adults with burns >15% TBSA. ∘ Children with burns >10% TBSA. • The optimal fluid and resuscitation algorithm is controversial. • In most units, fluid resuscitation is administered by one of the following regimes. • Fluid requirements are calculated from the time of burn, not time of admission. Parkland • 4 ml/kg/% burn of Hartmann’s solution in the first 24 hours after the burn. ∘ Half the fluid is given in the first 8 hours after injury. ∘ The second half is given in the next 16 hours. • Hartmann’s solution contains: ∘ Na+ 131 mmol/l Cl− 111 mmol/l Lactate 29 mmol/l K+ 5 mmol/l Ca2+ 2 mmol/l. Crystalloid sparing strategies • Infusion of large volumes of crystalloid is associated with oedema, increased total body sodium and abdominal compartment syndrome. • To mitigate these problems, some units introduce colloid as a crystalloid-sparing measure after 8 hours, when vascular permeability begins to decrease. • Other units may wait for 24 hours. ∘ Use of colloids in burns resuscitation is controversial. • Albumin has been used in adults for many years. • Fresh frozen plasma (FFP) is often used in children. • Randomised controlled trials of hydroxyethyl starch (HES) products in critically ill patients show increased risk of mortality and renal failure. ∘ Hence they have been withdrawn from the UK market. Muir and Barclay • Calculates the volume of human albumin solution to be given in the first 36 hours following a burn: ∘ 0.5 ml/kg/% burn gives a volume to be infused in each time period. ∘ The time periods are 3 × 4 hours, 2 × 6 hours and 1 × 12 hours. Burns 499 • Formulas give only estimates of fluid requirements. • They are unreliable at the extremes of age. • More fluid may be required for: ∘ Paediatric burns ∘ Delayed resuscitation ∘ Large burns ∘ Deep burns ∘ Burns where an accelerant, such as petrol, was used ∘ Electrical burns ∘ Inhalation injury ∘ Coexisting polytrauma. • Charles Baxter, who described the Parkland formula, reviewed its use: ∘ Accurate in 70% of adults. ∘ Overestimated in 18%; underestimated in 12%. ∘ Most often inadequate for burns >80% TBSA and patients >45 years. ∘ Few paediatric cases fell outside a range of 3.7–4.3 ml/kg/% TBSA burn. • The rate of infusion is modified to meet specific end points of resuscitation: ∘ Urine output is the best indicator of tissue perfusion – Aim for 0.5–1 ml/kg/h in adults; 1–1.5 ml/kg/h in children – Double this after high-voltage electrical injuries. ∘ Other parameters to be monitored: – Pulse, blood pressure, capillary refill – Core–peripheral temperature gradient – Respiratory rate – Urine osmolality. • Serial measures of arterial blood lactate and base excess also indicate adequacy of resuscitation. • Direct measurement of cardiac output with transoesophageal Doppler can identify patients who would benefit from inotropes or vasopressors. ∘ Inotrope of choice: norepinephrine; preferred vasopressor: dobutamine. ∘ Drugs are not used to ‘treat’ low urine output without first ruling out hypovolaemia, which is treated with more fluid. ∘ Injudicious vasopressor use worsens tissue hypoperfusion, causing extension of the burn and poor skin graft take. Factors specific to children • Proportionately greater surface area than adults. • Reduced physiological reserves. ∘ Because of this, children require additional maintenance fluid containing dextrose. • Daily maintenance fluid requirement: ∘ 100 ml/kg for the first 10 kg body weight ∘ 50 ml/kg for the next 10 kg body weight ∘ 20 ml/kg for the remainder of the body weight • Maintenance fluid is given enterally whenever possible. 500 Chapter 8 Complications of fluid resuscitation • Under-resuscitation ∘ Hypovolaemia ∘ Shock ∘ Renal failure ∘ Ischaemia-reperfusion injury ∘ MODS. • Over-resuscitation ∘ Generalised oedema ∘ Pulmonary oedema ∘ Cerebral oedema ∘ Intestinal oedema ∘ Compartment syndrome of limbs and abdomen. • Both under- and over-resuscitation may deepen the burn wound. The hypermetabolic response • Response to major injury is described by Cuthbertson’s ‘ebb and flow’ phases. • The ebb is a hypodynamic period lasting ≈48 hours following injury. • The flow phase follows, for up to a year, characterised by: ∘ Hyperdynamic circulation with doubling of cardiac output. ∘ Hyperthermia, maintaining core temperature 1–2 ∘ C above normal. ∘ Hypermetabolism, with increased oxygen consumption and CO2 production. • Circulating catecholamines and stress hormones create a diabetic-like state. • Increased glycogenolysis releases glucose, causing hyperglycaemia. • Most of the additional glucose is metabolised anaerobically at the burn wound, generating lactate. • Lactate is metabolised in the liver by gluconeogenesis, using amino acids derived from protein stores to replenish glucose levels. ∘ This process is known as carbohydrate cycling, and yields only a fraction of the energy that would be derived from aerobic metabolism. ∘ Breakdown of muscle protein for this purpose causes loss of lean body mass. ∘ Loss of >40% lean body mass is normally fatal. • Other complications of loss of lean body mass: ∘ Impaired immunity and increased infection. ∘ Impaired healing – dietary protein is preferentially used to restore lean body mass. ∘ Weakness – interferes with rehabilitation. ∘ Pressure sores. ∘ Pneumonia. Modulation of the hypermetabolic response 1 Nutrition 2 Environment control 3 Medication and hormone manipulation 4 Prevention of sepsis 5 Early wound closure. Burns 501 Nutrition • Aims of nutritional support: ∘ Maintenance of body weight and lean body mass (muscle protein). ∘ Electrolyte and vitamin homeostasis. Calculating calorie requirements • Nutritional requirements correlate with resting energy expenditure (REE). ∘ REE can be measured directly at the bedside using portable calorimeters that analyse oxygen consumption and carbon dioxide production. • Many formulas estimate energy requirements based on basal metabolic rate, with various multipliers used to account for physical activity and stress factors, such as a burn. ∘ The Harris–Benedict equation estimates REE. ∘ The Schofield equation estimates basal metabolic rate (similar to REE). • The Curreri formula is popular in adult burns: ∘ 25 kcal/kg + 40 kcal/% TBSA burn per day • The Galveston formula is used for children: ∘ 1500 kcal/m2 BSA for maintenance + 1500 kcal/m2 BSA burn. – Given the different surface area to volume ratios of children, this may be more appropriate than using body weight. • BSA (m2 ) of children is calculated by the Du Bois formula. ∘ Various web-based calculators are available for this purpose. Composition of nutritional supplementation • Standard enteral nutrition is fat-based: 44% lipid, 42% carbohydrate, 14% protein. • Using this feed, body weight is maintained by deposition of fat rather than replacement of lean body mass (muscle). • In burns, feeding should provide most calories as carbohydrate. • High carbohydrate diets stimulate protein synthesis by increasing endogenous insulin. ∘ Burn patients may require exogenous insulin to control hyperglycaemia. ∘ Tight glycaemic control improves wound healing; decreases infection and mortality. • Protein requirements are defined in terms of nitrogen needs. ∘ Nitrogen makes up about 15% of a protein. • Protein is provided to achieve a calorie to nitrogen ratio of 100:1. • Enteral nutrition for burns is typically 3% lipid, 82% carbohydrate, 15% protein. • Supplementation of vitamins C, A, E and folic acid, and trace elements copper, zinc, selenium, and iron is important in a burn >20% TBSA. ∘ Essential for normal cellular function and co-factors in many antioxidant enzymes. • Glutamine and arginine are conditionally essential amino acids. ∘ They become essential under conditions of severe stress, such as major burns. • Glutamine is a primary fuel for rapidly dividing cells. ∘ Supplementation improves wound healing rates; helps mucosal integrity. • Arginine enhances natural killer cell function and stimulates T lymphocytes. ∘ Supplementation also promotes wound healing. • Burn patients are prone to potassium, calcium, magnesium and phosphate depletion. 502 Chapter 8 Route of feeding • Healthy patients with burns <20% TBSA satisfy nutritional requirements by oral feeding and supplementary drinks. ∘ This may not be achievable with facial burns or painful upper limb burns. • Larger burns, confused or malnourished patients are best treated with enteral feeding. • Ideally, this is commenced within 4 hours of injury, via a nasogastric tube. • Major burns >40% TBSA have higher risk of gastric stasis and require repeated periods of fasting for theatre. ∘ For these patients, nasojejunal feeding tubes allow continuous feeding. • Enteral feeding provides nutrition to enterocytes that help maintain gut mucosal integrity and decrease bacterial translocation. • Parenteral nutrition is avoided in burns because of its negative effects: ∘ Decreased liver function with fatty infiltration ∘ Reduced immune function ∘ Line sepsis ∘ Increased mortality. Environment control • Burn patients are prone to hypothermia due to evaporative loss of water from wounds. • In addition, core and surface temperatures are elevated above normal by an upward shift in the set-point of the hypothalamus. • Energy to maintain body heat is provided by the cycling of carbohydrate and lipids. • This cycling relies on amino acids derived from muscle breakdown. • Warming the environment to 28–33 ∘ C provides environmental heat as energy for this insensible water loss. ∘ Decreases the metabolic burden and attenuates the hypermetabolic response. Medication and hormone manipulation Analgesics and anxiolytics • Pain and anxiety both contribute to the hypermetabolic state. • Opioid analgesia should be used, particularly before painful interventions: ∘ Dressing changes ∘ Physiotherapy ∘ Position change. • Benzodiazepines for anxiety. • Ketamine for more extensive dressing changes. Catecholamine antagonists • Propranolol is a non-selective β-blocker: ∘ Decreases heart rate ∘ Reduces cardiac work ∘ Decreases lipolysis ∘ Decreases REE with less muscle wasting Burns 503 ∘ ∘ Decreases peripheral lipolysis with less fatty infiltration of the liver Decreases thermogenesis. • Dose is titrated to reduce heart rate by 20%. Anabolic steroids • They decrease protein catabolism; increase protein synthesis. • Oxandrolone has been successfully used in burns. ∘ Oxandrolone’s virilising androgenic side effects are 5% those of testosterone, allowing its use in females. Hormones • Insulin helps maintain tight glycaemic control and inhibits muscle degradation. • Use of recombinant human growth hormone (rhGH) is controversial. ∘ Associated with increased mortality in adults, but not in children. • Potential benefits in children: ∘ Increased weight and height ∘ Improved lean body mass ∘ Improved bone mineralisation ∘ Decreased donor site healing time ∘ Decreased REE and cardiac output. Prevention of sepsis • Up to 75% of deaths in burn patients are attributable to sepsis. • Burn wounds are rapidly colonised with bacteria from: ∘ Environment ∘ Adjacent uninjured skin ∘ Bacteria located deep in uninjured hair follicles or sweat glands ∘ Haematogenous spread from the gut. • Gram-positive bacteria, e.g. Staphylococcus aureus, usually colonise the wound first. • Gram-negative bacteria take 5 days to reach significant levels. • Strategies that help prevent sepsis: ∘ Infection control procedures with barrier nursing and hand washing. ∘ Regular bathing or showering – decreases surface bacterial counts. ∘ Prevention of catheter-related infection by regular changes of intravascular lines. ∘ Topical antimicrobial agents: Silver sulfadiazine (SSD) 1% (e.g. Flamazine® ) • Effective against a wide range of bacteria and yeasts. • Active up to 24 hours. • When used on superficial burns it forms a yellow–grey pseudoeschar. ∘ This makes assessment of true burn depth difficult by mimicking full thickness burn. • Most common side-effect is transient leukopenia. • Toxic to fibroblasts, resulting in delayed wound healing. 504 Chapter 8 • Not used in the final weeks of pregnancy or first few months of life because the sulphonamide component causes kernicterus. Cerium nitrate-SSD (e.g. Flammacerium® ) • Useful for deep burns awaiting excision. • Forms leathery hard eschar with deposition of calcium. ∘ Prevents bacterial invasion; facilitates delayed tangential excision. Nanocrystalline silver (e.g. Acticoat® ) • More molecular surface area for reaction with water and subsequent release of silver ions and radicals. Povidone iodine (e.g. Betadine® ) • Duration of action only a few hours. • Repeated application to large burns can cause systemic iodine toxicity. Mupirocin (e.g. Bactroban® ) • Topical treatment of methicillin-resistant S. aureus (MRSA). Nystatin (e.g. Nystan® ) • Given topically or systemically to treat invasive fungal infections or colonisation of the alimentary tract. Sodium hypochlorite 0.025% • At this concentration, hypochlorite is bactericidal but without tissue toxicity. Honey • Honey’s antibacterial properties are attributed to: ∘ Release of H2 O2 by peroxidase in the honey. ∘ Bioflavinoids. ∘ Low pH of 3.6. ∘ High viscosity forms a barrier on the wound surface. • Prophylactic antibiotics are indicated before or during major burn excision. ∘ High incidence of bacteraemia during excision. • Indiscriminate use of antibiotics breeds resistant organisms: ∘ Multiple drug resistant Pseudomonas species. ∘ Acinetobacter baumanii-calcoaceticus (ABC) ∘ Stenotrophomonas maltophilia ∘ Extended-spectrum beta-lactamase (ESBL)-producing Klebsiella ∘ Vancomycin resistant Enterococcus (VRE) ∘ MRSA. • Early excision and wound closure removes the major substrate for bacterial growth and restores the natural barrier to bacterial invasion. Burns 505 Timing of surgery Emergency • Tracheostomy • Surgical decompression. Immediate burn wound excision • All burn wounds are operated on within 24 hours of injury. • Superficial partial thickness burns are treated with temporary skin substitutes until they heal spontaneously. • Deep burns are excised and skin grafted. • For deep burns >35–40% TBSA, there is insufficient autograft to cover excised areas. ∘ Residual ungrafted areas are closed with cadaveric allograft or temporary skin substitutes. • Allografted areas are gradually replaced with autograft after donor sites epithelialise to allow re-cropping. • Advantages: ∘ Modulation of hypermetabolic and systemic inflammatory response by removal of dead tissue. ∘ Operating early is associated with less blood loss in children. • Disadvantages: ∘ Logistics of organising a resource-intensive procedure: – Multiple surgical teams to limit operative time. – High demand for blood products. – Intensive care facilities. ∘ May not be appropriate for the elderly or physiologically unfit. Early serial burn wound excision • Can be defined as within 72 hours of the burn. • Usually up to 25% TBSA burn excised at each visit to theatre at 48-hour intervals. • By waiting until after resuscitation is complete, the burn wound is said to be stable. ∘ Decreases risk of excising potentially viable tissue. • For large burns, the aim is burn volume reduction by excising large confluent areas such as the back or anterior trunk. • Staged autografting is required for deep burns >35% TBSA. • Residual unexcised deep burns are covered with topical antibacterial agents. • Superficial partial thickness burns are treated with simple dressings, 1% SSD or temporary skin substitutes. • Advantage: ∘ Inflicts less of a physiological ‘hit’. • Disadvantages: ∘ Prolongs the hypermetabolic response. ∘ Possible increased incidence of bacteraemia associated with repeated excision. ∘ If the patient becomes unwell before total burn excision is complete, unexcised deep burn must be left in situ until the patient recovers. 506 Chapter 8 Intermediate • Most small (non-life-threatening) indeterminate depth burns are treated this way. • Typically present with mixed patches of superficial burn that will re-epithelialise and patches of deeper burn that will heal by scarring. • Early excision would remove areas that would have otherwise healed without scarring, thus worsening the outcome. • Patients are therefore treated conservatively for 10–14 days. • Following reassessment of the wound at that time, a decision is made as to whether remaining unhealed burn will heal within 3 weeks. ∘ In general, wounds that heal <3 weeks do so without scar formation. • Wounds that need >3 weeks to heal are treated as deep burns with excision and skin grafting. • 78% of wounds treated conservatively for >3 weeks form hypertrophic scars. Late • Surgery is classified as late if performed >3 weeks after the burn. • Late surgery may be appropriate for non-life-threatening burns in patients awaiting optimisation of medical co-morbidities. ∘ Their wounds may be treated with cerium nitrate-SSD while they await surgery. • This is a technique of necessity in low-income environments: ∘ Patients tend to present late following a burn, often in poor condition. ∘ Limited availability of experienced staff and resources. Burn excision Tangential excision • Burn eschar is shaved repeatedly in thin layers with a skin graft knife. • Excision stops when healthy, bleeding tissue is encountered. ∘ Needing to cause bleeding is a disadvantage. • Features suggestive of inadequate excision: ∘ Lack of bleeding. ∘ Dull, yellow–grey appearance of the dermis. – Healthy dermis is white and glistening. ∘ Pink–brown bloodstained appearance of subcutaneous fat. – Healthy fat is uniformly yellow. ∘ Thrombosed blood vessels. Fascial excision • Excision to deep fascia is sometimes indicated in massive burns. • Used to limit bleeding in areas where tourniquet cannot be used. • Using cutting diathermy minimises blood loss. • Perforating vessels are cauterised as they are encountered. Burns 507 • Advantages: ∘ Less blood loss. ∘ More certainty regarding wound bed viability. • Disadvantages: ∘ Longer operating time. ∘ Contour defects with undesirable cosmetic results. ∘ Circumferential excision can cause distal limb oedema. ∘ Greater risk of exposure of non-graftable structures, e.g. bone, tendon. ∘ Cutaneous denervation. Amputation • Indicated for unsalvageable limbs, e.g. after high-voltage electrical injury. Techniques for minimising blood loss • Minimising blood loss reduces risks of transfusion: ∘ Transfusion-related acute lung injury ∘ Allergy and anaphylaxis ∘ Coagulation factor depletion ∘ Hypocalcaemia, hyperkalaemia, acid–base disturbance ∘ Acute haemolytic transfusion reaction ∘ Bacterial or viral contamination. • Strategies for minimising blood loss: ∘ Tumescent infiltration of donor and excision sites with 1:1,000,000 epinephrine. ∘ Topical epinephrine soaks following excision. ∘ Tourniquets used on limbs. ∘ Permissive hypotension. ∘ Systemic terlipressin, a vasopressin analogue, reduces blood loss in burns and is useful in cases refractory to norepinephrine. ∘ Systemic recombinant factor VIIa (NovoSeven® ) decreases transfusion requirements in burns. ∘ Topical surgical sealants, e.g. Tisseel® . – Contains human fibrinogen and thrombin with bovine aprotinin. – Shortens the time to achieve haemostasis. ∘ Tranexamic acid is an anti-fibrinolytic used systemically in trauma and other branches of surgery. – Topical use anecdotally minimises blood loss in burn surgery. Wound closure • Temporary ∘ Biological dressings – Organic – Synthetic 508 Chapter 8 • Permanent ∘ Autograft ∘ Skin substitutes. Biological dressings • Organic or synthetic. • Characterised by good wound adherence, ‘sealing’ the wound from the environment. Organic Allograft skin • Without sufficient autograft skin, the following can cover acute wounds: Live-related allograft • Harvested from family members; not an option in most countries. Live-unrelated allograft • Freshly harvested from human organ donors. • Adheres and revascularises quicker than cadaveric allograft. • Not available in the United Kingdom. Cadaveric-unrelated allograft • This may be: ∘ Stored in glycerol after lyophilisation (freeze-drying) ∘ Cryopreserved at −80 ∘ C ∘ Irradiated. • Glycerol-preserved skin has a longer lifespan than cryopreserved skin. • Allograft allows wound closure following immediate or early excision when there are limited autograft donor sites. ∘ Reduces evaporative fluid loss, heat loss and the hypermetabolic response. • Disadvantages include the theoretical risk of transmitting disease. • Cryopreserved skin may contain viable cells that cause an inflammatory reaction. The Alexander technique • This uses two layers of skin graft, known colloquially as the ‘sandwich’ technique. ∘ Inner layer of widely meshed autograft. ∘ Outer layer of finely meshed allograft to protect the wound during healing. • As the autograft heals and epithelialisation spreads, the allograft is shed. • Useful in patients with limited donor sites where widely meshed autograft will not adequately close the wound to reduce the hypermetabolic response. Human amnion • Used extensively in low-resource environments due to its ready availability. • Useful for superficial partial thickness burns. Burns 509 Porcine xenograft • Useful for temporary cover of healing superficial burns when allograft not available. • It is not viable and does not revascularise, requiring replacement every few days to avoid infection. Synthetic Biobrane® • Bilaminate dressing of thin, semipermeable silicone film with partially embedded nylon fabric. • Porcine dermal collagen is chemically bound to the fabric, forming a complex 3D matrix. • Blood and fibrin clots in the nylon matrix, thereby firmly adhering the dressing to the wound until epithelialisation occurs. • Provides good pain relief; not usually removed until healing is complete. ∘ Used for paediatric scalds. ∘ Also used on skin graft donor sites and excised wounds awaiting grafting. • Biobrane gloves allow early physiotherapy for superficial hand burns. • It has no antimicrobial action; wound infections are not uncommon. TransCyte® • Consists of a polymer membrane and neonatal human fibroblast cells. • Cells are grown on nylon mesh coated with porcine dermal collagen, which is bonded to a thin layer of silicone. • Proliferating fibroblasts secrete human dermal collagen, matrix proteins and growth factors. • The product is frozen for storage, killing the fibroblasts but leaving the tissue matrix and bound growth factors intact. • It is applied similarly to Biobrane. Autograft skin • Once excised, a burn wound must be closed to avoid desiccation and infection. • The gold standard is autograft, but its availability is limited. • In large burns, sheet autograft is reserved for face and hands due to its superior cosmetic appearance compared to meshed autograft. • Also used early for cover of prospective tracheostomy or central venous line sites. Meshed split thickness skin graft • Meshing allows greater wound surface area to be covered from a given donor site surface area. • Bleeding tends to escape from under the graft rather than form haematoma. • Meshed grafts contour better than non-meshed grafts. • Disadvantage: honeycomb appearance when healed. • Autograft is generally meshed at ratios of 1.5:1, 2:1, 3:1 or 4:1. • Grafts meshed at 6:1 resemble Venetian blinds, making it difficult to ensure all the graft is placed ‘shiny side down’. 510 Chapter 8 Full thickness graft • Rarely used as primary cover in acute burns. ∘ Can be used for some small full thickness burns. ∘ May be required for acute cover of eyelid burns. • Full thickness graft is indicated mainly in secondary burns reconstruction. • Advantages of full thickness over split thickness grafts: ∘ Better colour and texture match with surrounding skin. ∘ Less contracture. ∘ More durable. Skin substitutes • Skin substitutes, as distinct from biological dressings, become incorporated permanently into the wound closure. Integra® • Bilaminar dermal template composed of: ∘ Thin outer layer of silicone ‘epidermis’. ∘ Thick inner layer of bovine tendon collagen and shark cartilage glycosaminoglycan (GAG). • The inner layer behaves like extracellular matrix that organises fibroblasts and collagen into a neodermis. • After 21 days, the outer silastic layer is peeled off and replaced with thin split skin graft. • Said to give better skin pliability, durability and cosmetic appearance than split skin graft alone. • Can cover acutely excised massive burns or resurface areas of troublesome scarring. • It is not antimicrobial; incidence of infection in the acute setting is significant. • Integra is also available as a single layer, without the outer silicone layer. Matriderm® • Single layer dermal template composed of: ∘ Bovine dermal collagen ∘ Bovine nuchal ligament elastin. • Thinner than Integra; applied with thin skin graft in a single stage. • The need for skin graft makes it unsuitable for use in large acute burns. Cultured epithelial autograft • Tissue culture techniques can grow autologous keratinocytes from a small patch of patient skin. • A cultured epithelial autograft (CEA) cell suspension can be sprayed onto wounds after 1 week in culture. • Alternatively, a sheet of CEA cells can be fabricated after about 3 weeks. • Wounds covered solely with keratinocytes have poor skin function and develop scar contracture. Burns 511 Cuono technique • Addresses problems of poor skin function by grafting CEA onto an allograft dermal bed. • Allograft is used for temporary wound closure while cell culture is in progress. • Once the allograft has revascularised, epidermis is removed by dermabrasion leaving viable allograft dermis onto which the CEA is applied. ∘ The dermal element of the allograft may survive, since graft rejection is primarily mediated by epidermal Langerhans cells. • Sprayed CEA cells are also effective at hastening skin graft donor site healing. • CEA is usually reserved for patients with massive full thickness burns. Complications of burns Systemic inflammatory response syndrome (SIRS) and sepsis • SIRS is manifested by two or more of: ∘ Temperature >38 ∘ C or <36 ∘ C ∘ Heart rate >90 beats per minute ∘ Respiratory rate >20 per minute or PaCO2 <32 mmHg ∘ White cell count >12,000 or <4000/μl, or >10% band forms (immature neutrophils). • Infection is an inflammatory response to microorganisms or invasion of normally sterile tissues. • Sepsis is infection with two or more SIRS criteria. • Severe sepsis is sepsis with organ dysfunction. • Septic shock is sepsis with persistent hypotension despite fluid resuscitation. • MODS is altered organ function in an acutely ill patient necessitating intervention to maintain homeostasis. • Given almost all major burn patients satisfy these criteria, some burn units raise the threshold for diagnosis of sepsis, with higher temperature and white cell count. • Differentiating sepsis from the normal burn hypermetabolic response can be difficult. Toxic shock syndrome (TSS) • Toxin-mediated acute life-threatening illness. • Young children with small burns are at risk. • Usually caused by S. aureus or Group A Streptococcus (GAS). • Features: pyrexia, rash, hypotension, MODS, desquamation of palms and soles. • Non-specific prodrome of myalgia, vomiting, diarrhoea, headache. • Most cases are due to staphylococcal toxin TSST-1. ∘ Pyrogenic exotoxins from GAS also cause TSS. • These toxins act as superantigens. ∘ Superantigens directly activate T cells, triggering massive cytokine production. • High-dependency or ITU treatment is usually required. ∘ Systemic antibiotics, FFP, supportive therapies for organ dysfunction. • Early diagnosis is crucial – mortality is 50% once shock is established. 512 Chapter 8 Cardiovascular and respiratory complications • Discussed earlier. Renal impairment • Also known as acute kidney injury; affects 25% of patients with burns >20% TBSA. • Aetiology is multifactorial: ∘ SIRS ∘ Hypotension ∘ Pulmonary dysfunction, which purportedly drives SIRS and MODS ∘ Nephrotoxic drugs, including antibiotics and NSAIDs ∘ Sepsis ∘ Myoglobinuria – Due to large full thickness burns and high-voltage electrical injury. – Causes renal failure by acute tubular necrosis. • Treatments to prevent progression to acute tubular necrosis: ∘ Maintain supra-normal urine output of 1–2 ml/kg/hour. ∘ Mannitol as an osmotic diuretic. – It is also renoprotective due to its action as a free radical scavenger. ∘ Alkalinisation of the urine by sodium bicarbonate infusion is controversial. – May be unnecessary if fluid resuscitation is adequate. Electrolyte imbalance • Disorders of electrolyte balance are common. • Initial resuscitation is characterised by hyponatraemia and hyperkalaemia. ∘ Sodium is lost from the extracellular space following changes in cell permeability. ∘ Hyperkalaemia from cell lysis and tissue necrosis following the burn. • The week following resuscitation is characterised by hypernatraemia, with low potassium, magnesium, calcium and phosphate. • Hypernatraemia is the result of: ∘ High total body sodium, due to resuscitation with salt-containing fluids. ∘ Release of intracellular sodium back into the extracellular space. ∘ Resolution of oedema, which concentrates the intra- and extracellular sodium. ∘ Urinary retention of sodium via the renin-angiotensin-aldosterone system. • In addition, there is a free water deficit. ∘ Results from insensible losses from the burn wound. • Free water deficit can be replaced with an electrolyte-free solution, e.g. 5% dextrose. ∘ This also helps restore the extracellular space to an isotonic state. • To estimate free water requirement: ∘ (25 + %TBSA burn) × BSA (m2 ) = ml/hr of free water required. • Some centres use furosemide to offload excess body sodium in the days following resuscitation. Gastrointestinal complications • Include paralytic ileus and gastrointestinal ulcerations. ∘ Curling’s ulcers are duodenal stress ulcers in burns. Burns 513 • Small bowel ischaemia and stasis allow bacterial translocation, which drives SIRS. • These effects are minimised by early enteral feeding. Neurological complications • Global weakness or neuropathy occurs after protracted ITU admission. • Neuropsychiatric complications are common: ∘ Anxiety, depression, post-traumatic stress disorder. Musculoskeletal complications • Osteoporosis due to disuse and altered calcium metabolism. • Heterotopic ossification following burns is uncommon. ∘ Decreased joint range of motion should be investigated with plain X-ray. Referral guidelines • UK National Burn Care Referral Guidance (2012): ∘ All burns ≥2% TBSA in children or ≥3% in adults ∘ All full thickness burns ∘ All circumferential burns ∘ Any burn not healed in 2 weeks ∘ Any burn with suspicion of non-accidental injury (NAI). • The following require discussion with a Burns Consultant: ∘ All burns to hands, feet, face, perineum or genitalia ∘ Any chemical, electrical or friction burn ∘ Any cold injury ∘ Any unwell or febrile child with a burn ∘ Concerns regarding burn injuries and co-morbidities that may affect burn treatment or healing. Non-accidental injury (NAI) • NAI is a catch-all term that encompasses ideas such as ‘abuse’ and ‘neglect’. • NAI can be considered as two main concepts: 1 Acts – Positive action to do something, such as: • Forcing a child into hot water. • Stubbing out a cigarette on someone’s skin. – Rare events; account for ≈0.1% of paediatric burns. 2 Omissions – Failure to act, such as: • Inadequately supervising a child or failing to protect them from injury. – Account for ≈20% of paediatric burns. • NAI also affects the elderly and other vulnerable adults. • Characteristic history and examination findings should arouse suspicion of NAI. History • Two features with greatest evidence base: 1 The described mechanism of burning is inconsistent with examination findings. 514 Chapter 8 2 The mechanism of injury is incompatible with the child’s developmental stage, e.g. a 2-month old cannot climb onto an oven. • Features with weaker evidence base: ∘ Delayed presentation ∘ Vague or changing history ∘ Inadequate supervision ∘ Sibling blamed for the burn ∘ Lack of guilt on the part of the parent ∘ Lack of engagement with the burn team. Examination • Behavioural changes, e.g. ‘frozen watchfulness’. • Obvious patterns from cigarettes or lighters. • Restraint injuries. • Burns difficult to sustain by accident, e.g. isolated burns of buttocks and perineum. • Symmetrical burns of uniform depth with a clear upper limit suggest deliberate immersion. • Sparing of flexion creases suggests fetal positioning at the time of immersion. • ‘Doughnut sign’ – area of spared skin surrounded by scald, suggestive of forced immersion where skin in contact with the bottom of the bath is spared. • Other signs of physical abuse: bruises of varying age, coexisting fractures, poor hygiene, lack of engagement with other healthcare professionals, e.g. GP or Health Visitor. • There may be a background of domestic violence. • Suspicion of NAI requires immediate admission to hospital for assessment. • Local child or vulnerable adult protection policies should be followed. Emergency management of a child with a 40% burn • Emergency management of burns is a common exam question at all levels: • First aid ∘ Stop the burning process ∘ Cool the wound. • Brief history ∘ Nature and time of the burn. ∘ Factors suggesting inhalation and associated injuries. • Airway management with cervical spine control. • Breathing ∘ Expose the chest to assess ventilation ∘ Administer oxygen. • Circulation ∘ Control haemorrhage ∘ Monitor pulse and blood pressure ∘ Insert two large-bore cannulas. Burns 515 • Disability ∘ Assess conscious level. • Exposure ∘ Remove all clothing; exclude other injuries. ∘ Evaluate TBSA and depth of burn. ∘ Assess need for escharotomies or fasciotomies. ∘ Cover burns with non-circumferential cling film. ∘ Weigh the patient. ∘ Wrap the patient in a warming blanket or place under a radiant heater. • Resuscitate ∘ Analgesia, e.g. intravenous morphine or intranasal diamorphine. ∘ Take blood for full blood count, cross-match, urea and electrolytes, glucose and drug and alcohol screen. ∘ Start fluid resuscitation with Hartmann’s solution (Parkland formula). ∘ Start maintenance fluid with dextrose solution, e.g. 4% dextrose with 0.45% saline. ∘ Take blood gases and check carboxyhaemoglobin levels if relevant. ∘ Tetanus status. • Monitor ∘ Monitor pulse, blood pressure, respiratory rate. ∘ Check core temperature and avoid hypothermia. ∘ Urinary catheter and nasogastric tube. ∘ Test urine for myoglobinuria or haemoglobinuria; consider a pregnancy test. • When stable, transfer to a Burn Centre after anaesthetic review of the airway. • If TBSA cannot be estimated, resuscitate the patient as a 20% burn. ∘ Patients tolerate this amount of fluid without becoming overloaded, even if no burn exists. Surgical strategy for the acute management of a major burn • Effective management requires planning and communication. • Agreement on treatment priorities can trigger debate amongst team members. • Many valid approaches exist, based on patient circumstances, surgeon preferences and Burn Team experience. • One suggested approach is outlined below. ∘ Adapt if the patient becomes unstable, cold, coagulopathic, acidotic or develops intractable hypotension. • It assumes resuscitation and emergency procedures, e.g. escharotomy, have already been completed. Preparation • Patient is anaesthetised supine in a warmed operating theatre. • Blood products available in theatre. • Head shaved to assess burn or harvest scalp skin. 516 Chapter 8 • Anterior trunk cleaned with povidone-iodine or chlorhexidine. • Planned sites of burn excision and skin harvest are marked prior to infiltration with 1:1,000,000 epinephrine. ∘ Marking is important because blanching from epinephrine makes subsequent burn assessment difficult. Anterior excision and harvest • Anterior donor sites harvested, dressed with alginate or Biobrane; graft meshed 3:1. • Small piece of unmeshed skin is reserved for CEA. • Anterior deep burns are excised and covered in epinephrine-soaked gauze. Posterior excision and harvest • Patient is turned prone to address the back. ∘ Prone is the most dangerous of all anaesthetised positions. ∘ Complications of inhalation injury, e.g. pneumonia, develop a few days after resuscitation and may preclude prone positioning for a week or longer. ∘ This means leaving up to 25% unexcised burn in situ, with attendant risks of deep infection, sepsis and exacerbation of the hypermetabolic response. ∘ This is why the back is addressed during this early window of opportunity. • Back burns excised; donor sites harvested. • Wound closed, usually with allograft or autograft-allograft sandwich, secured with surgical staples. • Dressed with antibacterial silver dressing, e.g. Acticoat, and patient turned supine. Anterior wound closure and limb excision • Haemostasis of anterior trunk has been achieved by epinephrine soaks and tamponade effect of being prone. ∘ If the anterior trunk was excised at this point rather than at the beginning, blood and debris would contaminate the back dressing. • Anterior trunk wounds are closed with Integra, allograft or sandwich technique. • If tracheostomy required in the next 7–10 days, this is anticipated by placing sheet graft on the neck to expedite healing. • Limbs excised under tourniquet control and wounds closed with Integra, allograft or sandwich technique. • Upper limbs splinted in a position of safe immobilisation. Burn reconstruction • Secondary burn reconstruction aims to improve function, comfort and cosmesis. Prevention • Undesirable post-burn sequelae may be prevented by: ∘ Positioning and splinting. ∘ Thick sheet grafts if possible, particularly on face, neck, hands. Burns 517 ∘ ∘ Respecting facial aesthetic subunits. Early scar management with splints, facemasks and silicone. • Early excision and grafting decreases post-burn hypertrophic scarring and contracture. Assessment • Numerous subjective scar assessment scales have been described: ∘ Vancouver Scar Scale ∘ Visual Analog Scale ∘ Manchester Scar Scale. • None of them measure: ∘ TBSA of the scar ∘ Functional disability caused by the scar ∘ Effects of pain and itch on activities of daily living. • Vancouver Scar Scale is most widely used; it scores these features of a scar: ∘ Vascularity ∘ Pigmentation ∘ Pliability ∘ Height. Potokar’s five Ps • Tom Potokar, Consultant Burns Surgeon at the Welsh Centre for Burns & Plastic Surgery, uses this mnemonic in his Burn Reconstruction Multidisciplinary Clinic: 1 Problems – Patient problems are explored with another mnemonic – F2PIP • Form (appearance of scars) • Function (restrictions on activity) • Pain (absent, moderate or severe) • Itch (absent, moderate or severe) • Psychological issues (how these problems affect daily life). 2 Priorities – In what order does the patient rank their problems? – Any urgent problems requiring acute treatment? 3 Possibilities – What treatment options are available? 4 Perceptions – Patient’s expectations for treatment and outcomes? – Are they realistic? 5 Plan – Treatment plan developed with the patient and other MDT members. – Customary to ‘start with a winner’ – a reliably successful operation that increases patient confidence. Timing • Ideally, delay reconstruction until wounds are closed and scars/grafts have matured. • However, certain circumstances mandate early intervention. 518 Chapter 8 Acute • Eyelid contractures causing exposure keratitis. • Neck contractures causing airway difficulties. • Progressive contractures causing irreversible damage, e.g. nerve compression. • Severe microstomia. Intermediate • Surgery in the intermediate period is required as gains are made with physical rehabilitation. • Increasing joint range of motion places tension on burn scars. ∘ Scars respond by hypertrophy and contraction. • Relieving tension by surgical release and reconstruction favourably influences scar maturation. Late • Late operations are for stable deformities of mature scars and grafts. • Patients may seek treatment for uncomfortable scars or cosmesis. Surgical management of post-burn contractures Analysis • Contractures may be intrinsic or extrinsic. ∘ Intrinsic contractures result from scarring within the affected area. ∘ Extrinsic contractures occur when scarring remote from the affected area creates tension. • Eyelid ectropion results from either intrinsic or extrinsic contractures. ∘ Making the correct diagnosis allows surgery to be directed at the underlying cause. Treatment • Contracture release can be incisional or excisional. • Resulting defects are reconstructed with vascularised tissue rather than grafts if possible. • Flaps often give superior functional and cosmetic results, particularly over a gliding surface. • Flaps also match the growth of children, minimising the number of operations required. • Options for reconstruction: ∘ Local flaps – Z-plasty – W-plasty – Y-V plasty – Four or five flap Z-plasty. ∘ Regional flaps – Pedicled or free fasciocutaneous and myocutaneous flaps. ∘ Skin substitutes – Integra – Matriderm. Burns 519 ∘ ∘ Tissue expansion Skin grafts. • Long-standing contractures may also require joint release. Scar management • Scar management aims to prevent hypertrophic scarring. • If abnormal scarring occurs, it aims to achieve a functional and aesthetically acceptable outcome. Preventative therapies Pressure therapy • Pressure garments and custom-made acrylic facemasks prevent hypertrophic scars. • Proposed mechanisms of action: ∘ Limiting blood supply, which decreases collagen synthesis. ∘ Increasing apoptosis within the scar. • Empirical regimes recommend continuous pressure of 15–40 mmHg for 23 hours each day for at least 6 months. • Patient discomfort limits compliance. Massage • Done with moisturiser; helps scar pliability and remodels adhesions between scars and surrounding tissues. • May help pain and mental relaxation. • Evidence for massage is weak, but is widely used nevertheless. Silicone • Topical silicone has been used since the early 1980s. • Proposed mechanisms of action: ∘ Occlusion of the scar – Causes changes in collagen orientation, cellular activation and cytokine expression. ∘ Hydration – Inhibits fibroblast proliferation and collagen production in vitro. • Silicone sheets should be worn for >12 hours a day for 2 months. • Therapy can begin as soon as 2 weeks after wound healing. • Also available as spray or gel, which conform better over joints. Treatments for abnormal scars Intralesional corticosteroid injection • Intralesional triamcinolone is the most popular treatment for hypertrophic and keloid scars. • There is little good quality RCT data to support its use. • Its effect is thought to be due to: ∘ Reduction of the ongoing inflammatory process in the scar. ∘ Reduced collagen and GAG synthesis. 520 Chapter 8 ∘ ∘ • • • • Increased collagen degradation. Inhibition of fibroblast proliferation. Response to treatment varies from 50% to 100%. Recurrence on withdrawal of treatment is seen in up to 50%. Most effect is had with young, immature scars. Side effects: dermal and fat atrophy, depigmentation, telangiectasia, injection pain. Cryotherapy • Liquid nitrogen is used alone or combined with intralesional steroid injection. • May work by inducing vascular damage, leading to tissue necrosis. • Success varies between 32% and 74% after repeated applications. • Side effects: permanent pigmentation changes, skin atrophy, blistering. Surgical excision • Total excision for small hypertrophic scars amenable to direct closure. • Subtotal excision for large scars that formed due to delayed wound healing. • Excising keloids is controversial due to high recurrence rates. • Surgery is usually combined with another treatment modality to modulate the scarring process, such as steroids, pressure therapy or radiotherapy. Radiotherapy • Effective treatment for scars; usually combined with surgical excision. • Thought to work by inhibiting neovascular buds and fibroblasts, thus decreasing collagen production. • Radiotherapy is given within 48 hours of excision. • Some are reluctant to offer this treatment due to risk of carcinogenesis. Laser • Vascular lasers, e.g. pulsed dye laser or KTP, destroy blood vessels to cause localised ischaemia. • This is thought to cause breakdown and realignment of collagen fibres, reducing scar colour, height and firmness. • Fractional CO2 lasers have been used to release contracted hypertrophic scars. 5-Fluorouracil • Normally used as an anti-metabolite in cancer therapy. • Used off-label as an anti-scarring agent after years of safe intra-ocular use. • Thought to work by inhibiting fibroblast proliferation. • Side effects include pain and local ulceration. • Systemic absorption is minimal, but patients should use contraception during treatment. Rehabilitation of burns • The goal of burn rehabilitation is to assist the patient throughout the recovery process to achieve the best possible functional outcome. Burns 521 • Rehabilitation begins on admission and involves: ∘ Maintaining correct positioning to minimise contractures. ∘ Maintaining range of motion to minimise deformity. ∘ Decreasing oedema. ∘ Preventing pulmonary complications by regular chest physiotherapy. ∘ Preventing loss of lean muscle mass. ∘ Returning the patient to normal activity as soon as possible. Chemical burns • Caused by: ∘ Alkalis ∘ Acids ∘ Other chemicals. • The chemical agent may still be active on arrival in hospital, causing ongoing injury. • Chemical burns are inflicted by various mechanisms: ∘ Oxidation, e.g. sodium hypochlorite ∘ Reduction, e.g. hydrochloric acid ∘ Corrosion, e.g. phenol ∘ Protoplasm poisoning, e.g. formic acid ∘ Vesiculation, e.g. dimethylsulfoxide ∘ Desiccation, e.g. sulphuric acid. Alkali burns • Cause liquefactive necrosis. • Often appear less dramatic than acid burns. ∘ However, liquefaction allows deeper penetration of the alkali. • Alkali burns of the eye need prompt treatment. ∘ Rapid corneal penetration of alkalis produces scarring, opacification and perforation. • Alkali burns are commonly caused by: ∘ Household cleaning solutions ∘ Oven cleaners ∘ Fertilisers ∘ Cement. Acid burns • Cause coagulative necrosis. • Should be irrigated within 10 minutes to minimise deep damage. • Hydrochloric acid fumes can cause airway oedema and pneumonitis. Hydrofluoric acid Pathophysiology • Hydrofluoric acid (HF) is extremely dangerous. ∘ Hydrogen ions cause acid burns. ∘ Free fluoride ions cause extensive local and systemic liquefactive necrosis. 522 Chapter 8 • HF burns are very painful. • Fluoride reacts with calcium and magnesium, causing systemic hypocalcaemia and hypomagnesaemia. ∘ Requires monitoring and treatment with intravenous infusion. • Fluoride also poisons the Na–K ATPase, causing efflux of K+ from cells. • Seemingly trivial cutaneous exposure can be life-threatening. • ECG should be monitored for prolongation of the Q–T interval. Management • Initial management is dilution with copious irrigation. • Topical 10% calcium gluconate gel inactivates free fluoride ions and provides pain relief. ∘ More gel is applied when the pain returns. • Pain refractory to topical calcium requires subcutaneous infiltration of 0.5 ml 10% calcium gluconate per centimetre square. • If extensive subcutaneous infiltration is impractical, e.g. in the fingers, intra-arterial infusion of calcium solutions is done. Phosphorus burns • Phosphorus is present in: ∘ Fireworks ∘ Firearms ∘ Insecticides ∘ Fertilisers. • Phosphorus spontaneously ignites in air; requires copious irrigation. • 0.5% copper sulphate solution impedes oxidation and turns the phosphorus black, making it easier to identify and remove. General management of patients with chemical burns 1 Clothing and causative agent is removed. ∘ Avoid pulling clothing over the head – chemicals could get into the eyes. 2 Wounds are copiously irrigated for at least 1–2 hours. ∘ pH of the effluent indicates adequacy of treatment. ∘ Exceptions: – Sodium, potassium and lithium should not be irrigated with water. • Water causes these to ignite. • Fires are first extinguished with a fire extinguisher. • Then cover with oil to isolate the metal from any water. – Phenol is not water soluble – remove with 50% polyethylene glycol. – Concentrated sulphuric or hydrochloric acid can release heat on contact with water. • Neutralise these with soap – contains weak NaOH – before irrigation. 3 Many workplaces have Diphoterine® available for chemical burns. ∘ Diphoterine is a chelating molecule with binding sites for many different compounds including acids, bases, oxidising agents, reducing agents, vesicants, irritants and solvents. Burns 523 ∘ ∘ 4 5 6 7 8 Can be used on skin and eyes. It decreases burn severity, pain, and results in fewer debridements. Systemic toxicity should be treated. Examine nails, hair and web spaces for traces of residual chemical. Ocular injury requires urgent continuous irrigation and ophthalmology review. ∘ Irrigation is conveniently achieved with a Morgan lens. Toxicology services may know of specific antidotes for certain substances. After the initial first aid phase, chemical burns are treated as for thermal burns. ∘ If excision is required, this should be done early. Electrical burns • Current (A) = Voltage Resistance ( I= V R ) • UK household voltage is 230 V; 120 V in the United States. • Average resistance of the human body is 500 Ω. • The current received in an electric shock from household supply is therefore: ∘ 0.46 A in the United Kingdom ∘ 0.24 A in the United States. • Ventricular fibrillation (VF) may result from shocks of 1 A. • VF is more common after a shock with high-frequency alternating current. Classification Voltage • Electrical burns can be classified as: ∘ Low voltage: <1000 V ∘ High voltage: >1000 V ∘ Extremely high voltage: lightning strikes. Current • Electrical burns can be classified as: ∘ Direct current (DC): tends to cause a single muscle spasm, throwing the body away from the electrical source. – Injury is primarily caused by blunt trauma. – Arrhythmias can arise if the shock is delivered during a vulnerable phase of the cardiac cycle. ∘ Alternating current (AC): three times more dangerous than DC for a given voltage. – Continuous muscle tetany occurs between 40 and 110 Hertz (Hz); mains electricity is supplied at 50 Hz in the United Kingdom and 60 Hz in the United States. • This can prevent the victim from releasing the electrical source. Mechanism • Direct contact ∘ Electrothermal heating 524 Chapter 8 • Indirect contact ∘ Arc ∘ Flame ∘ Flash. Lightning • Lightning injury occurs by different mechanisms: ∘ Direct strike – Usually fatal. ∘ Side flash or ‘splash’ – Occurs when lightning strikes a structure, e.g. a tree, which then discharges current through the air or ground to an individual. ∘ Contact – Occurs when a person touches part of the current pathway. ∘ Ground current or ‘step voltage’ – Describes the potential difference between a person’s feet as lightning current spreads radially through the ground. – The human body is a better conductor than the earth, so current preferentially flows through the legs and body than the ground. – Cows and horses are killed this way because their legs are so far apart. • Lightning strikes are neither AC or DC, but a massive current impulse. • Lightning may be conducted as external ‘flashover’, limiting internal conduction. • Burns and deep muscle damage are therefore rare, but asystole, respiratory arrest and neurological damage are common. • ‘Lichtenberg figures’ on the skin are said to be pathognomonic of lightning injury, but they last only a few hours. Pathophysiology Low voltage • Low voltage injuries can cause cardiac arrest and death. ∘ Burns cause little tissue destruction; usually managed conservatively. ∘ If ECG is normal, cardiac monitoring is not required. High voltage • High-voltage injuries primarily burn by heating. ∘ Secondary injuries: blunt trauma due to falls and dislocations after massive muscle contraction. • Injury severity is proportional to current, resistance and duration of contact. • Current is determined by voltage and resistance. • Resistance is determined by the current’s pathway through the body. ∘ Different tissues have different resistance; more resistance means more thermal energy generated. ∘ Nerves, muscles and blood vessels have low resistance. Burns 525 ∘ ∘ ∘ • • • • • Fat, tendons and bones have high resistance. Skin has intermediate resistance; lowered by sweating, increased by heavy callouses. Prolonged contact causes blistering that decreases resistance. – Allows current to surge into deeper tissues, causing extensive destruction. The current pathway affects the injuries seen: ∘ Through the chest: myocardial problems ∘ Through the brain: respiratory arrest, seizures ∘ Through the orbits: cataracts. Current is concentrated at points of contact with the source and ground. ∘ Causes ‘entry and exit’ wounds, which should always be sought. Trivial cutaneous wounds can hide extensive deep damage due to heat generation within bones that burns muscle from within. ∘ Compartment syndrome is common. ∘ Myoglobinuria indicates muscle necrosis. Electroporation is a suggested mechanism of injury with high voltages. ∘ Electricity causes protein configuration changes in cell membranes, forming ‘pores’. ∘ The resulting free passage of water and electrolytes causes cell death. ∘ Can cause muscle necrosis even when there is no sign of thermal injury. Cardiac monitoring, fluid resuscitation, renoprotection and early fasciotomy are essential. Cold injury • Cold injury is a thermal injury where heat energy is removed from, rather than added to, the body. • Classified as either freezing or non-freezing. Freezing injury Frostnip • • • • Mildest form of cold injury; common in skiers. Acral regions (fingers, toes, ears, nose) become white and insensate. On simple rewarming, skin becomes hyperaemic with paraesthesiae. Full recovery is expected. Frostbite • As skin cools to 0 ∘ C, extracellular ice crystals form. • Ischaemia results from shunting of peripheral blood to maintain core temperature. • Extracellular crystals draw water out of cells. • The resulting intracellular hyperosmolarity causes cell damage and protein denaturation. • Microvascular endothelial damage and vascular stasis exacerbate the situation. • If the microvasculature does not recover, thrombosis and gangrene ensues. • Rewarming is usually done in a hospital environment where a full ATLS survey is completed and systemic hypothermia treated. 526 Chapter 8 • Frostbitten extremities are rewarmed in a circulating water bath at 37–39 ∘ C for up to 1 hour. ∘ The end-point of rewarming is when a red–purple colour appears and soft tissues become pliable. • The limb is then protected from infection and accidental minor trauma. • Ibuprofen is given as an anti-inflammatory and analgesic. • There is some evidence of a benefit from thrombolytic therapy. • Fasciotomy may be required; amputation is usually delayed until demarcation is complete. Non-freezing injury Trench foot Affects soldiers whose feet have been wet, but not freezing, for prolonged periods. Occasionally affects civilians living rough. Causes a superficial, moist, liquefactive necrosis. Thought to be caused by a combination of: ∘ Near-freezing temperature ∘ Wet environment ∘ Dependancy ∘ Constriction by shoes and clothing. • Pathogenesis is divided into three overlapping phases: 1 Pre-hyperaemic phase (hours to days) – Limb is cold, swollen, discoloured and numb. 2 Hyperaemic phase (2–6 weeks) – Limb is red, swollen, with bounding circulation. 3 Post-hyperaemic phase (weeks or months) – Limb is warm with cold insensitivity. • Treatment involves washing and air-drying the feet, rewarming, bed rest and elevation. • • • • Conditions causing burn-like wounds • Rare causes of partial thickness skin loss are often managed in Burn Units. Toxic epidermal necrolysis (TEN) Rare, acute, potentially fatal skin reaction. Characterised by sheet-like skin and mucosal loss. Stevens–Johnson syndrome (SJS) is a milder form within the same disease spectrum. Most cases are attributable to a particular drug. Most common associations: allopurinol, co-trimoxazole, other antibiotics, anticonvulsants, NSAIDs. ∘ Mycoplasma infection and vaccinations are rare causes. • Genetic susceptibility is likely – associated with HLA mutations in Han Chinese. • • • • • Burns 527 • Pathogenesis believed to be immune-mediated – rapidly recurs if the causative drug is re-introduced. Diagnosis • Based on clinical and histopathological features. • Initially: erythematous skin macules with positive Nikolsky sign. • Hours later: epidermal detachment and blister formation. • Mucosal involvement affects eyes, mouth, oesophagus, upper respiratory tract, genitourinary tract and gastrointestinal tract. • TEN is differentiated from SJS by the TBSA involved: ∘ SJS: <10% TBSA involvement. ∘ TEN: >35% TBSA involvement. • An SJS–TEN overlap is diagnosed when 10–35% TBSA is involved. • Histopathology shows keratinocyte apoptosis and necrosis of all epidermal layers. ∘ This leads to widespread epidermal detachment. Prognostication • SCORTEN is a validated illness severity score to predict mortality risk in TEN/SJS. • Presence of each of these scores 1 point: ∘ Age >40 years ∘ Malignancy ∘ Heart rate >120 beats per minute ∘ Initial percentage of epidermal detachment >10% TBSA ∘ Serum urea >10 mmol/l ∘ Serum glucose >14 mmol/l ∘ Serum bicarbonate <20 mmol/l. • Predicted mortality ranges from 3.2% for score 1 to >90% for scores ≥5. • Patients with scores ≥3 should be managed on an ITU. Management • Identify and stop the causative drugs. • Score the disease with SCORTEN. • Transfer to a Burn Unit for intensive supportive care. ∘ Survival rates are significantly higher if transferred within 7 days (29.8% vs 51.4%). • Urgent ophthalmology review. • Fluid and electrolyte balance. • Whether or not blisters should be debrided is controversial. • No agreement on the ideal dressing. ∘ Biobrane seems ideal, but there is risk of infection, and new epidermolysis develops over time. • No specific intervention has conclusively shown benefit in TEN/SJS. 528 ∘ Chapter 8 Possible benefit from intravenous immunoglobulin, ciclosporin, anti-TNFα antibodies and plasmapheresis. Complications • Significant long-term morbidity affects >50% of TEN/SJS patients: ∘ Ocular: symblepharon, conjunctival synechiae, entropion with trichiasis. ∘ Cutaneous: scarring, irregular pigmentation. ∘ Mucosal: persistent erosions, phimosis, vaginal synechiae, nail dystrophy, diffuse hair loss. Staphylococcal scalded skin syndrome (SSSS) • Characterised by red, blistering skin that looks like a scald. • Caused by staphylococcal exotoxins: exfoliative toxins A and B. ∘ These are proteases that cleave proteins responsible for maintaining desmosomes. – Desmosomes bind epidermal cells to one another. ∘ If toxins are localised, they cause bullous impetigo. ∘ Systemic dissemination of toxins causes widespread blistering, called SSSS. • Predominantly affects children <5 years, especially neonates. • Risk of childhood mortality is 5%, but can be 60% in adults with co-morbidities. • Clinical appearances are similar to TEN/SJS. • Diagnosis is made on the histology of a frozen section: ∘ SSSS shows superficial epidermal blistering. ∘ TEN/SJS shows subepidermal blistering with necrotic keratinocytes. • Management is supportive with anti-staphylococcal antibiotics, e.g. flucloxacillin. • Recovery is usually rapid with complete healing within a week. Further reading Inhalation Aggarwal S, Smailes S, Dziewulski P. Tracheostomy in burns patients revisited. Burns 2009;35(7):962–6. Mlcak RP, Suman OE, Herndon DN. Respiratory management of inhalation injury. Burns 2007;33(1):2–13. Resuscitation Alvarado R, Chung KK, Cancio LC et al. Burn resuscitation. Burns 2009;35(1):4–14. Baxter C. Fluid resuscitation, burn percentage, and physiologic age. J Trauma 1979;19(11 Suppl):864–5. Baxter CR, Shires T. Physiological response to crystalloid resuscitation of severe burns. Ann N Y Acad Sci 1968;150(3):874–94. Blumetti J, Hunt JL, Arnoldo BD et al. The Parkland formula under fire: is the criticism justified? J Burn Care Res 2008;29(1):180–6. Surgery Cuono C, Langdon R, McGuire J. Use of cultured epidermal autografts and dermal allografts as skin replacement after burn injury. Lancet 1986;1(8490):1123–4. Burns 529 Desai MH, Herndon DN, Broemeling L et al. Early burn wound excision significantly reduces blood loss. Ann Surg 1990;211(6):753–9. Moiemen NS, Vlachou E, Staiano JJ et al. Reconstructive surgery with Integra dermal regeneration template: histologic study, clinical evaluation, and current practice. Plast Reconstr Surg 2006;117(7 Suppl):160S–174S. Ong YS, Samuel M, Song C. Meta-analysis of early excision of burns. Burns 2006;32(2):145–50. Sterling JP, Heimbach DM. Hemostasis in burn surgery--a review. Burns 2011;37(4):559–65. Paediatric burns Maguire S, Moynihan S, Mann M et al. A systematic review of the features that indicate intentional scalds in children. Burns 2008;34(8):1072–81. White MC, Thornton K, Young AE. Early diagnosis and treatment of toxic shock syndrome in paediatric burns. Burns 2005;31(2):193–7. Rehabilitation Falder S, Browne A, Edgar D et al. Core outcomes for adult burn survivors: a clinical overview. Burns 2009; 35(5):618–41. Non-thermal injury Kidd M, Hultman CS, Van Aalst J et al. The contemporary management of electrical injuries: resuscitation, reconstruction, rehabilitation. Ann Plast Surg 2007;58(3):273–8. Palao R, Monge I, Ruiz M et al. Chemical burns: pathophysiology and treatment. Burns 2010;36(3):295–304. Stanley JR, Amagai M. Pemphigus, bullous impetigo, and the staphylococcal scalded-skin syndrome. N Engl J Med 2006;355(17):1800–10. CHAPTER 9 Aesthetic Surgery CHAPTER CONTENTS Facelift, 530 Blepharoplasty, 541 Brow lift, 547 Rhinoplasty, 553 Genioplasty, 563 Liposuction, 565 Fat injection, 569 Body contouring, 572 Nonoperative facial rejuvenation, 581 Body dysmorphic disorder, 587 Further reading, 588 With all aesthetic patients, it is important to know: • What they perceive the problem to be. • What their expectations of surgery are. • Why they want the surgery. • Whether they have had any relevant previous surgery. • Whether they have any psychological problems that might affect their suitability for cosmetic surgery. Facelift • A surgical procedure designed to give a more youthful facial appearance. • Also known as rhytidectomy, derived from the Greek words ‘rhytis’ (wrinkle) and ‘ektome’ (excision). • Mainly addresses the lower two-thirds of the face and upper neck. Anatomy • This account of facial anatomy draws on Dr Bryan Mendelson’s concept of concentric layers. Key Notes on Plastic Surgery, Second Edition. Adrian Richards and Hywel Dafydd. © 2015 John Wiley & Sons, Ltd. Published 2015 by John Wiley & Sons, Ltd. 530 Aesthetic Surgery 531 • These layers are similar to those of the scalp: 1 Skin 2 Connective and subcutaneous tissue 3 Aponeurosis/muscle 4 Loose areolar layer 5 Periosteum. • In the face these layers are not homogeneous but modified in areas of specialised function. Layer 1: skin • Dermal thickness is related to the function and mobility of particular regions. • Thin, mobile dermis, e.g. eyelid, is more susceptible to the changes of ageing. Layer 2: subcutaneous tissue • Contains subcutaneous fat and retinacular fibres that connect the dermis to layer 3. • Thicker fat in the nasolabial area is known as the malar fat pad. ∘ This does not lie over the prominence of the zygoma but medial to it. • Where the fat layer is thick, retinacular fibres are longer and therefore more prone to weakness. Layer 3: musculoaponeurotic • This is a continuous layer over the forehead, scalp, temporal area, face and neck. • Sometimes formed by muscle, sometimes by fascia. • Exemplified on the scalp, where two separate muscles (occipitalis and frontalis) are invested in a fibrous sheath. ∘ Where there is no muscle, superficial and deep layers of this sheath fuse to form galea aponeurotica. • This layer has different names in different areas: ∘ Galea, over the scalp. ∘ Frontalis muscle, over the forehead. ∘ Superficial temporal fascia (also called temporoparietal fascia). ∘ Orbicularis oculi muscle and fascia, around the eyes and orbits. ∘ Platysma muscle, in the neck and lower face. ∘ Superficial muscular aponeurotic system (SMAS), in midface and lower face. • Muscles in this layer are indirectly attached to the skeleton by soft tissue: ∘ Frontalis is attached by deep galea along the superior temporal line. ∘ Orbicularis oculi is attached by the orbicularis retaining ligament at the orbital margin. ∘ Platysma is attached at its upper border by masseteric ligaments. • Mimetic facial muscles lie deep to this layer: corrugator supercilii, procerus, lip elevators and depressors. ∘ They arise directly from the skeleton with a short course to a focused insertion. 532 Chapter 9 Facial anatomy 1. Zygomatic arch Superior temporal fusion line Inferior temporal septum Frontal I II III IV V 3 2. Inferior temporal space 2 1 Zygomatic I II III IV V Buccal Parotid gland Mandibular Cervical Skin Subcutaneous fat SMAS Parotid–masseteric fascia with VII Zygomatic periosteum Skin Subcutaneous fat Superficial temporal fascia Parotid–temporal fascia with VII Superficial lamina of deep temporal fascia Superficial temporal fat pad Deep lamina of deep temporal fascia Temporalis Bone 3. Superior temporal space I II III IV V Skin Subcutaneous fat Superficial temporal fascia with VII Upper temporal space and layered fascia Deep temporal fascia Temporalis Bone Layer 4: loose areolar layer • On the scalp, this is a simple, mobile layer, which is easily dissected. • However, in the face, it contains: 1 Retaining ligaments 2 Spaces 3 Facial nerve branches. Retaining ligaments True retaining ligaments • Between dermis and periosteum: 1 Zygomatic retaining ligaments, from the zygoma (McGregor’s patch). – Form the anatomical basis for the mid-cheek groove. 2 Orbicularis retaining ligament, from the orbital margin. 3 Mandibular ligament, from the parasymphyseal region of the mandible. False retaining ligaments • Between dermis and underlying fascial layers (no bony attachment): 1 Platysma-auricular fascia – A wide area of attachment anterior to the ear. – Consists of fused layers of SMAS, parotid–masseteric fascia and parotid capsule. – Incorporates platysma-auricular ligament and Loré’s fascia. 2 Masseteric ligaments, from the anterior border of masseter. Aesthetic Surgery 533 Spaces • Areas devoid of attachments between bone and overlying soft tissue. • Allow mobility of facial soft tissues. • Bounded by the retaining ligaments, which provide stability. • They explain the appearance of malar mounds, jowls and labiomandibular folds (marionette lines). Prezygomatic space • Bound by orbicularis retaining ligament superiorly and zygomatic ligaments inferiorly. • Ligament laxity allows the space to bulge, causing malar mounds. Premasseter space • Bound by platysma-auricular fascia posteriorly and masseteric ligaments anteriorly. • Roof is platysma muscle. • Degeneration of platysma results in bulging of the space. • Forms a jowl behind the mandibular ligament and a labiomandibular fold. Masticator space • Medial to masseter; contains the buccal fat pad. • Degeneration of masseteric ligaments and platysma causes the space to bulge inferiorly, deepening the labiomandibular fold. Facial nerve branches • Gross anatomy of the facial nerve (VII) is reviewed in Chapter 3, ‘Facial palsy’. • Branches of VII enter the face within the parotid gland. • They exit the anterior parotid to lie on the surface of masseter. ∘ They are protected here beneath masseter fascia (layer 5). • VII is at risk as it changes plane to supply the muscles in layer 3. • This occurs at the vertical line of retaining ligaments – zygomatic, masseteric and mandibular. • Frontal and mandibular branches are most at risk. Frontal branch • Leaves the parotid just inferior to the zygomatic arch. ∘ Found on the underside of layer 3 within parotid–masseteric fascia (layer 4). • Passes superficial to the middle third of the zygomatic arch. • Sandwiched between superficial temporal fascia (layer 3) and deep temporal fascia (layer 5), within a continuation of parotid–masseteric fascia: the parotid–temporal fascia (layer 4). • The branch is avoided by dissecting deep to it, directly on deep temporal fascia. Mandibular branch • At risk where it is fixed against a ligament: ∘ Platysma-auricular fascia posteriorly. ∘ Mandibular ligament anteriorly. • The branch can be protected by dissecting superficial to platysma. 534 Chapter 9 • Although classically described as running 1–2 cm inferior to the mandible, this distance increases with ptosis of the lower face. Layer 5: periosteum and deep fascia • Periosteum is the deepest soft tissue layer of the scalp. • In the lateral face, periosteum is continuous with the masseteric and deep temporal fasciae, where the deep muscles of mastication take origin. • Approximately 2 cm superior to the zygoma, deep temporal fascia splits into two laminae that envelop the superficial temporal fat pad: ∘ The superficial lamina of deep temporal fascia inserts onto the anterosuperior surface of the zygomatic arch. ∘ The deep lamina of deep temporal fascia inserts onto the posterosuperior surface of the zygomatic arch. • The equivalent layer in the neck is the investing layer of deep cervical fascia. Blood supply • Arterial supply of the facelift flap is largely based on external carotid artery branches: ∘ Facial artery – paranasal, perioral and submental perforators. ∘ Transverse facial artery (branch of the superficial temporal artery). – Transverse facial artery perforators are divided when mobilising the facelift flap from the malar prominence. • Dissection medial to the nasolabial folds risks compromising blood supply from facial artery perforators. • The middle temporal artery (branch of the superficial temporal artery) supplies deep temporal fascia and its associated fat pad. ∘ Injury to this artery can cause fat pad atrophy and temporal hollowing. Sensory nerve supply • Branches of the trigeminal nerve (V) and cervical plexus. • Supraorbital and supratrochlear nerves are at risk during brow lift surgery. • Infraorbital nerve is at risk during subperiosteal dissection in volumetric facelifts. • Auriculotemporal nerve runs with the superficial temporal artery. ∘ At risk if the vessel is ligated. • Great auricular nerve (C2, C3) is at risk when dissecting inferior to the ear. ∘ Emerges from the posterior border of sternocleidomastoid to pierce the deep investing fascia 6.5 cm inferior to the tragus. ∘ Division results in numbness of the lower pinna. Assessment of the patient History • Specific questions for patients considering a facelift: ∘ Whether they smoke. ∘ Whether they have high blood pressure. ∘ Relevant medication, such as aspirin. ∘ Relevant medical history – healing or bleeding disorders, diabetes, rheumatoid. ∘ History of previous facial surgery, including cosmetic procedures. Aesthetic Surgery 535 Aesthetic examination of the face • Begin with patient and surgeon seated, facing each other. ∘ Further information is gleaned from a lateral view. • Assessment for facelift inevitably overlaps with brow lift and blepharoplasty. • Almost all of the examination is inspection. • Proceed logically by arbitrarily dividing the vertical face into thirds. General • Blood pressure • Skin quality ∘ ‘Dermatochalasis’ means loss of elasticity and support in the skin. • Wrinkles • Pigment irregularities • Sun exposure • Facial scars, including acne scars • Skin tumours • Obvious asymmetry. Upper third • Hairline – a posterior hairline does not hide endoscopic scars well. • Brow position: ∘ Males – the brow should sit at the superior orbital rim. ∘ Females – the brow arches above the rim, with apex in line with the lateral limbus. • Signs of brow ptosis: ∘ Lateral orbital wrinkles or crow’s feet. ∘ Transverse forehead creases due to compensatory frontalis contraction. ∘ Glabellar frown lines. ∘ Lateral orbital hooding. • Some also make these objective measurements: ∘ Vertical distance from mid-pupil to brow apex. ∘ Vertical distance from brow apex to hairline. Middle third • Redundant upper eyelid skin. • Hollowing of the orbit. • Lower eyelid laxity and wrinkles. • ‘Festoons’ – due to redundant orbicularis muscle. • Palpebral bags – due to postseptal fat bulging. • Malar projection. • Earlobe position. • Signs of midface ptosis: ∘ ‘Elongation’ of the lower eyelid ∘ Scleral show ∘ Mid-cheek groove ∘ Nasojugal groove/tear trough – Formed by the junction between orbital and palpebral parts of orbiularis. – Located just inferior to the medial canthus and nasolacrimal crest. 536 ∘ Chapter 9 – Continues laterally along the orbital margin as the palpebromalar groove. Malar mounds – Discrete triangular bulges of skin and fat overlying the malar prominence. – Not the same as malar fat pads. – Also called malar bags or malar crescents. Lower third • Deepening of nasolabial folds • Perioral wrinkles • Downturning oral commissures • Deepening of labiomandibular folds (marionette lines) • Jowls • Mandibular projection and dental occlusion. Neck • Loss of definition of the mandibular border. • Blunted cervicomental angle, normally 105∘ –120∘ . • Excess fat deposition. • Platysmal bands. Features of facial ageing 1 4 3 5 7 2 6 8 9 10 13 11 12 14 15 16 17 18 1. Forehead and glabella creases 2. Lateral brow ptosis 3. Eyelid dermatochalasis 4. Orbital hollowing 5. Lower lid laxity 6. Palpebral bags 7. Nasojugal groove 8. Palpebromalar groove 9. Malar bags 10. Mid-cheek groove 11. Generalised dermatochalasis 12. Nasolabial fold 13. Perioral wrinkles 14. Downturning oral commissures 15. Labiomental crease 16. Jowls 17. Loss of neck definition 18. Platysmal bands Aesthetic Surgery 537 • Assess facial motor and sensory nerve function. • Note the underlying aesthetic problems. • Propose a surgical plan based on the patient’s wishes. ∘ Determine the most appropriate vectors of lift. • Ancillary procedures may be required to achieve patient satisfaction: ∘ Post-operative disappointment may be due to perioral wrinkles. – Treated by resurfacing rather than surgery. Preoperative counselling Explanation • Limitations of surgery: ∘ Facelift does not address forehead and periorbital lines. ∘ ‘Bags under the eyes’ persist if blepharoplasty is not done. ∘ Nasolabial folds are not significantly affected. ∘ Fine wrinkles, e.g. perioral, are not corrected. – Resurfacing can be performed at the same time as the facelift. • Nature of surgery: ∘ General anaesthesia. ∘ Post-operative facial bandages. ∘ Incisions – most require a preauricular incision with these extensions: – Into the temple – within the hair or at the anterior hairline. • Hairline incisions are visible but do not shift the hairline after skin redraping. – Into the posterior hair – usually arches high over the mastoid behind the ear, follows the posterior hairline for a few centimetres, then enters the posterior hair at an angle. Facelift incision • Post-operative course: ∘ When the patient can go home. ∘ What they will look like – bruising and swelling are common. 538 ∘ ∘ Chapter 9 Post-operative precautions, e.g. avoiding exercise; sleeping with the head elevated. Arrangements for follow-up. Possible complications Immediate complications • Haematoma (1–3% in women, 7–9% in men). ∘ Most occur within 24 hours of surgery; requires prompt evacuation. ∘ Risk factors: preoperative hypertension, male gender, nonsteroidal anti-inflammatory drugs (NSAIDs), smoking, open platysmaplasty. • Sensory nerve damage. ∘ Numbness of the facelift flap is usual – typically resolves within 12 months. ∘ Great auricular nerve is the most common named nerve damaged (<7%). • Motor nerve damage ∘ Persistent VII dysfunction in up to 2.6%. – May be due to traction, cautery, strangulation by sutures or neurotmesis. ∘ Marginal mandibular branch is most commonly injured, followed by frontal and buccal branches. Early complications • Skin necrosis (1–3%) ∘ Most occurs in the postauricular area; treated conservatively. ∘ Smoking increases risk of necrosis 12-fold. • Infection (<1%) • Parotid gland pseudocyst • Wound dehiscence. Late complications • Alopecia (<2%) • Troublesome scars: ∘ Visible scarring ∘ Hypertrophic or keloid scars ∘ Ear distortion – ‘pixie ear’ deformity ∘ Steps in the hairline. • Asymmetry • Skin pigment changes. Techniques of facelift • Classified according to the plane of dissection: ∘ Subcutaneous – Skin only – With traditional SMAS dissection – With extended SMAS dissection – With SMASectomy Aesthetic Surgery 539 – With SMAS plication – With suture suspension (‘MACS’; Minimal Access Cranial Suspension) ∘ Sub-SMAS (‘deep-plane’) ∘ Subperiosteal. • Most facelifts involve some form of SMAS manipulation. Subcutaneous Skin only • Subcutaneous undermining of skin on the cheek and neck. • Cheek skin is redraped in a posterosuperior vector. • Neck skin is redraped posteriorly to avoid transferring creases onto the cheek. • Early recurrence is a risk because the underlying structures are not tightened. With traditional SMAS dissection • Decreases jowling and defines the angle of the mandible. • The SMAS is incised as an inverted ‘L’: ∘ Transverse incision inferior to the zygomatic arch. ∘ Vertical preauricular incision extended along the anterior border of sternocleidomastoid. • Dissection continues anterior to the parotid, where SMAS is more mobile. • SMAS is redraped in a posterosuperior vector, excess trimmed and sutured to the immobile edge of SMAS along the original incision line. • Platysma is sutured over the mastoid. With extended SMAS dissection • Differs from traditional SMAS dissection: 1 Transverse incision above the zygomatic arch. 2 Anterior dissection is taken over zygomaticus major. • More extensive dissection provides additional malar augmentation. With SMASectomy • A strip of SMAS is excised along a line connecting the angle of the mandible and lateral canthus. • Cut edges are sutured to each other, securing mobile SMAS to more immobile SMAS over the parotid. • Platysma is sutured over the mastoid. With SMAS plication • Plication sutures are placed in SMAS, in a similar location as for SMASectomy. • Because SMAS is not excised, plication can augment the volume of facial soft tissues: ∘ The dog ear at the superior end of plication augments the malar. ∘ The dog ear at the inferior end is usually excised. • Branches of VII are at risk if sutures are placed too deep. 540 Chapter 9 With suture suspension (‘MACS’) • Developed by Tonnard and Verpaele of Gent, Belgium (2002). ∘ A variant of ‘short scar’ facelift. ∘ The scar is restricted to the temporal and preauricular segments of a traditional facelift. • Soft tissues are suspended from deep temporal fascia, above the zygomatic arch, by two or three loops of purse string sutures. ∘ There is no true ‘cranial suspension’. • The lift is almost purely vertical, which can cause ruching of excess skin around the earlobe. ∘ The vertical vector can also elevate the temporal hairline. – Prevented by a hairline incision, rather than an incision within the hair. Sub-SMAS (‘deep-plane’) • Also known as Skoog’s procedure. • Cheek dissection is deep to SMAS. ∘ No dissection between SMAS and skin. • The composite flap of skin, subcutaneous fat and SMAS is tightened and secured. • This thicker flap is less prone to necrosis but poses greater risk of facial nerve damage. • Hamra’s ‘composite rhytidectomy’ is a modification of this procedure. ∘ Includes orbicularis oculi in the flap. Subperiosteal • Described by Tessier; applies craniofacial principles to facelifting. • Originally the technique used traditional craniofacial incisions – coronal, lower eyelid and upper buccal sulcus. • Recently, endoscopic techniques minimise the size of the incisions. • Advantages: protection of VII, which is superficial to the dissection plane. • Disadvantages: limited effects on excess skin and laxity of the lower face and neck. Management of the malar fat pad • Elevating the malar fat pad restores cheek fullness. • Areas such as the tear trough are difficult to correct; can be addressed with fat grafting. • The malar fat pad can be approached in one of three ways: 1 Temporal incision, using endoscopic instruments 2 Lower eyelid incision 3 Classic facelift incision. Management of the neck • Divarication of platysma produces unsightly bands medially. • The neck can be improved by: ∘ Submental defatting, by open submental incision or liposuction. ∘ Plication of the medial borders of platysma to each other, through a submental incision. ∘ Suturing lateral platysma to platysma-auricular fascia or mastoid, via a facelift incision. ∘ Resection or division of prominent platysmal bands. ∘ Suspension of ptotic submandibular glands. Aesthetic Surgery 541 Blepharoplasty • Blepharoplasty shapes or modifies the appearance of the eyelids. ∘ Can be both cosmetic and functional. • Traditionally involves the removal of varying amounts of skin, muscle and fat. • Eyelid anatomy is discussed in Chapter 3, ‘Oculoplastic surgery’. Assessment of the patient • Aims to establish three things: 1 The problems affecting the eyelids and periorbital tissues. 2 Coexisting medical conditions that increase risk of surgical complications. 3 Features that predispose to post-operative dry eye and visual changes. Medical history • Diabetes, hypertension, connective tissue disease, thyroid disease, heart disease and clotting disorders. • Medications: antiplatelet/anticoagulant drugs, over-the-counter remedies. • Smoking and alcohol. Ophthalmological history • Problems with vision • Previous ocular or periocular trauma • Glaucoma • Contact lens use • Dry eyes or excessive tearing • History of keratomileusis (‘laser eye surgery’) ∘ Periorbital cosmetic surgery should be avoided within 6 months of refractory surgery. Examination • Eyelids are assessed in the context of the whole face as discussed for facelift. • In addition to a facial assessment, the following specific features are examined: General • Lagophthalmos (inability to close the eyelids) • Blink reflex • Bell’s phenomenon (see Chapter 3, ‘Oculoplastic surgery’) • Visual acuity, using a Snellen chart • Extraocular movements • Visual fields. Brow and upper eyelid • Patients requesting blepharoplasty may have compensated brow ptosis: ∘ Brow ptosis is ‘compensated for’ by the continual action of frontalis. – This elevates the brow to lighten the burden of skin on the upper lid. ∘ Compensated brow ptosis is revealed by descent of the eyebrows as the eyes are closed. 542 Chapter 9 ∘ Blepharoplasty in such patients may worsen their appearance. – It would allow the eyelids to open without compensatory elevation of the brow. – Subsequent relaxation of frontalis would cause eyebrow descent, resulting in a hooded, stern or aged appearance. – They may benefit from brow lift prior to, or in conjunction with, blepharoplasty. • If brow ptosis is apparent, hold the brow in the correct position for the remainder of upper eyelid examination: ∘ Estimate the amount of excess tissue by gently pinching eyelid skin. ∘ Note the location of prominent fat pads or a prolapsed lacrimal gland. ∘ Measure the upper lid skin crease position from the centre of the lash line in downward gaze. ∘ Eyelid ptosis – the upper lid normally covers 2–3 mm of the superior limbus. ∘ Eyelid position can be measured by the margin-reflex distance (see Chapter 3, ‘Oculoplastic surgery’). Lower eyelid and midface • Assess skin excess and postseptal fat bulging. • Note the position of the medial and lateral canthus and canthal tilt: ∘ The lateral canthus is normally 2 mm superior to the medial canthus. ∘ Negative canthal tilt may indicate disinsertion or laxity of the lateral canthus. • Lid laxity – snap test, anterior lid traction (see Chapter 3, ‘Oculoplastic surgery’). • Scleral show is a significant finding associated with: ∘ Proptosis ∘ Lower lid laxity ∘ Poor lower lid support. – Each increases the risk of complications if not properly addressed. • Globe position relative to the orbital rim is assessed on lateral inspection: ∘ A ‘negative vector relationship’ exists if the anterior cornea is anterior to the infraorbital rim. ∘ Such patients have a prominent eye with poor globe support. – Overcorrection of lateral canthal positioning, superior to the expected location, avoids lower lid malposition and corneal exposure. ∘ A ‘positive vector relationship’ exists if the anterior cornea is posterior to the infraorbital rim. ∘ Such patients have deep-set eyes. – Posterior placement of the lateral canthus avoids anterior lower lid malposition. Preoperative counselling Explanation • Limitations of surgery: ∘ Crow’s feet lateral to the orbit are not addressed. ∘ Festoons and malar bags are not corrected by blepharoplasty alone. Aesthetic Surgery 543 ∘ ∘ Uncorrected brow ptosis affects the result. Some wrinkles persist – excess tension to remove wrinkles causes lagophthalmos. • Nature of surgery: ∘ Type of anaesthesia. ∘ Incisions and technique of blepharoplasty. ∘ Patients may wake up with eye pads on. • Post-operative course: ∘ Eye grittiness or soreness. – Treated pre-emptively with eye ointment and damp eye pads at night. ∘ What they will look like. ∘ Precautions, e.g. not straining or leaning over, desisting from contact lens use for two weeks, avoiding NSAIDs. ∘ Arrangements for follow-up. Possible complications Immediate complications • Eyelid haematoma or bruising. • Retrobulbar haematoma (see Chapter 3, ‘Maxillofacial trauma’). ∘ Rare but serious complication; quoted incidence 1 in 2500 cases. ∘ Bleeding from a postseptal artery can compress the neurovascular structures of the eye, causing permanent blindness. ∘ It is a surgical emergency – requires bedside decompression. ∘ Intravenous mannitol and acetazolamide can decrease intraocular pressure. ∘ An urgent ophthalmology opinion is sought. • Visual changes. ∘ Diplopia is usually temporary; attributable to oedema or haematoma. ∘ Permanent strabismus if extraocular muscles or motor nerves are damaged. ∘ The muscles most commonly affected are the inferior and superior oblique. • Corneal abrasions and globe perforation. ∘ Can be prevented by the use of corneal shields. Early complications • Dry eye syndrome, consisting of itching, grittiness, burning, mucoid secretions, frequent blinking, conjunctival infection. ∘ Clinical assessment can predict the occurrence of this syndrome. ∘ Pre-emptive treatment can therefore be given: – Ocular protection with patches – Temporary tarsorrhaphy or Frost sutures – Lateral canthopexy – Aggressive corneal lubrication – Control of oedema with compresses and head elevation. • Lower lid malposition ∘ Common complication, attributed to: – Excessive removal of skin, muscle or fat – Scar contracture 544 • • • • Chapter 9 – Intramuscular haematoma – Paralysis of orbicularis oculi – Adhesions of the orbital septum – Uncorrected lower lid laxity – Proptosis. ∘ Can be prevented by lateral canthal suspension. ∘ Treatment is usually conservative with massage and taping. ∘ Surgery involves lateral canthopexy, skin grafts or posterior lamella spacer grafts. Infection ∘ Rare; post-operative dry eye increases risk of corneal infection. Chemosis ∘ Oedema of the conjunctiva and cornea; relatively common and self-limiting. Asymmetry ∘ Slight asymmetry is common. ∘ Corrective surgery is delayed until inflammation and oedema have resolved. Ptosis ∘ Caused by local anaesthetic, oedema or intramuscular haematoma. ∘ May result from iatrogenic injury to the levator aponeurosis, which should be repaired during surgery. Late complications • Lagophthalmos. ∘ Usually resolves once oedema subsides. ∘ Initial treatment is non-operative with massage, taping and eye lubrication. ∘ Long-term, some patients require scar release and full thickness skin grafts. • Undercorrection of excess upper eyelid skin. ∘ Can be addressed by secondary excision or, if appropriate, brow lift. • Excessive postseptal fat resection. ∘ Gives an undesirable ‘hollowed-out’ look. ∘ Treatments include fat transfer or injectable fillers to mask the orbital rim. Techniques of blepharoplasty • If brow lift is also planned, it is done before blepharoplasty to avoid overexcision of upper lid skin. • If facelift is also planned, it is done after blepharoplasty to avoid overexcision of lower lid skin. Upper blepharoplasty • Local or general anaesthesia. • The lower border of the excision is marked in the supratarsal crease. ∘ This is approximately 10 mm superior to the ciliary margin. ∘ Continued laterally in a natural skin crease but not beyond the lateral orbital rim. ∘ It should not extend beyond the caruncle medially to avoid scar webbing. • The upper border of the skin excision is determined at multiple points by gently pinching the eyelid skin with forceps. Aesthetic Surgery 545 Mark parallel to the inferior skin marking but >10 mm below the inferior border of the brow. The marked strip of skin is excised. If there is upper lid fullness, the medial and central fat pads are accessed through small incisions in the orbital septum. ∘ The septum is opened superiorly to avoid injury to the levator aponeurosis. Conservative fat excision has been advocated. ∘ Excessive fat removal may result in a ‘hollowed-out’ skeletal appearance. ∘ Extensive excision can injure neurovascular structures and extraocular muscles. A prolapsed lacrimal gland can be resuspended in the lacrimal fossa with dissolving sutures. Some also excise retro-orbicularis oculi fat (ROOF) to reduce heaviness of the lateral brow. ∘ The supraorbital nerve and frontal branch of VII must be protected. Definition of the supratarsal crease can be enhanced by securing pretarsal orbicularis and dermis to the levator mechanism during wound closure. ∘ • • • • • • Blepharoplasty markings Lateral orbital rim Upper eyelid markings > – 10 mm Level of the caruncle >10 mm Level of the inferior punctum Transcutaneous subciliary incision Lower blepharoplasty • The technique of choice is controversial; outcomes are not as predictable as for upper blepharoplasty. • General anaesthesia is usually preferred. • There is a variety of options for each stage of the procedure. Approach Transcutaneous • A single subciliary incision, limited medially by the lacrimal punctum. • Continued beyond the lateral canthus inferolaterally into a skin crease for approximately 5 mm. 546 Chapter 9 • Preserve a 10 mm vertical skin bridge between upper and lower lid incisions to avoid scar webbing. • Once the skin is incised, dissection proceeds in one of these planes: ∘ Skin flap method – Skin is separated from underlying orbicularis to the infraorbital rim. – The junction between pretarsal and preseptal orbicularis is incised in the line of fibres to access the septum and orbital fat. – The skin flap is redraped and redundant skin excised. ∘ Skin–muscle flap method – Skin is separated from underlying pretarsal orbicularis, but preseptal orbicularis is elevated with the skin to the inferior orbital rim. – This exposes the septum for access to orbital fat, leaving pretarsal orbicularis intact. – The skin–muscle flap is redraped and excess tissue excised. – This approach may damage or denervate orbicularis, leading to lower lid malposition. – However, proponents cite post-operative electromyographic evidence of functioning pretarsal orbicularis muscle. Transconjunctival • This does not address skin excess, which can be treated by a separate skin-only excision or nonsurgical resurfacing. • The transconjunctival approach has two options: ∘ Preseptal – Incision through conjunctiva just inferior to the tarsus, ≈5 mm from lid margin. – At this level, capsulopalpebral fascia and septum are also divided. – Dissection proceeds between the septum and orbicularis to the infraorbital rim. ∘ Retroseptal – Incision several millimetres inferior to the tarsus, through conjunctiva and capsulopalpebral fascia only. Management of orbital fat Excision • Medial, central or lateral compartments are entered through small incisions in the orbital septum. ∘ The transconjunctival retroseptal approach enters the fat compartments without violating the septum. • Inferior oblique lies between medial and central compartments. Anterior repositioning with septal reset • Aims to camouflage the lid–cheek junction by releasing the septum from the arcus marginalis at the inferior orbital rim. • Allows orbital fat to prolapse over the inferior orbital margin, softening the skeletal lid–cheek junction. • The septum is reattached anteroinferior to the inferior orbital margin. • Carries significant risk of ectropion, necessitating lateral canthal support. Aesthetic Surgery 547 Lateral canthal support • Done on completion of blepharoplasty but prior to skin resection. • Consider the vector relationship of the globe to the orbital rim. • Providing canthal support is routine for some surgeons. • Others tailor support according to laxity on anterior traction of the lower lid: Minor laxity (1–2 mm of anterior traction) • Temporary tarsorrhaphy. ∘ Helps protect the cornea; prevents early cicatricial ectropion. • Orbicularis muscle sling. ∘ The superolateral edge of the lower lid preseptal orbicularis is dissected free from skin and septum for about 1 cm. ∘ This is transposed to the lateral orbital rim, via the upper blepharoplasty wound. ∘ Secured with sutures to periosteum. Moderate laxity (3–6 mm of anterior traction) • Lateral canthopexy ∘ Tightens the lower lid by suturing canthal ligament and tarsal plate to lateral orbital rim periosteum. ∘ Can be achieved by transcanthal canthopexy: – Small incision in the lateral canthus. – Both needles of a double-armed permanent suture are passed through the incision to emerge in the lateral part of the upper lid blepharoplasty wound. – The suture is secured as described for the orbicularis muscle sling. Severe laxity (>6 mm of anterior traction) • Lateral canthoplasty. ∘ Division and repositioning of the inferior limb of the lateral canthal tendon. ∘ Can be performed through the upper blepharoplasty wound. • For significant lower lid redundancy, cantholysis with full thickness lid resection, i.e. Kuhnt-Szymanowski procedure, may be required. Brow lift Anatom

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