VASCULAR MALFORMATIONS
Pathogenesis
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Vascular malformations are errors of embryonic vasculogenesis.
Two processes are responsible for the formation of new blood vessels: vasculogenesis
and angiogenesis
o Angiogenesis involves the formation of vascular sprouts from pre-existing
vessels,
o Vasculogenesis - formation of blood vessels from differentiating angioblasts
and their organization into a primordial vascular network, consisting of the
major blood vessels of the embryo
Vasculogenesis
 Occurs in Three Stages
Stage 1 (week 2-6)
 At the end of the second week of embryonic development, the primitive vascular
plexus is formed.
 mesodermal precursors of endothelial and blood cells differentiate into solid clumps
of epithelioid cells and isolated masses called blood lakes
 The inner cells differentiate into hematopoietic precursors, and the outer cells
flatten to form primitive endothelial cells.
 Periendothelial support cells (neural crest derived) are then recruited to encase
these endothelial cells. In capillary vessels, these cells are pericytes; in larger vessels,
they are smooth muscle cells; and in the heart, they are myocardial cells
 Lymphatic channels arise as outgrowths from veins within the early capillary plexus
by the end of the 5th week
Stage 2 (week 7-12)
 In the retiform stage beginning on approx day 48 (week 7), venous and arterial
channels appear on either side of the capillary network through angiogenesis. Errors
in morphogenesis during this stage results in vascular malformations.
 Angiogenesis occurs through two different mechanisms: sprouting and
nonsprouting. Small blood vessels can be formed by sprouting (budding) from
preexisting, larger vessels. In intussusception (nonsprouting angiogenesis) the
preexisting vessels are split by transcapillary pillars or invagination by surrounding
pericytes and extracellular matrix. A possible third mechanism involves the
intercalated growth of blood vessels, allowing merging of preexisting capillaries to
increase diameter and length
 The primitive lymphatic skeleton is mature by the ninth week of development
Stage 3
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consists of maturation and further differentiation of vascular channels
Theories
1.
abnormal neural regulation process.
o The autonomic nervous system may influence the development of vascular
system through neuroregulatory control of the vascular smooth muscle
o Most likely hypothesis to explain Port-wine stains in a trigeminal distribution
and the presence of hyperhydrosis over the malformation
o It is suggested that the defect lies in the maturation of the cutaneous
sympathetic innervation causing vasodilation.
o A significant decrease in the nerve density and a increase in the vessel to
nerve ratio seen in this malformation
2.
abnormal gene regulation
o proteins/molecules and receptors that play a part in vasculo/angiogenesis may
play a role in malformations
o These include: FGF, VEGF and VEGF-R, integrin αv β3, receptor tyrosine
kinase family TIE, PDGF, angiopoietin, TGF, tissue factor
Classification Clinical, Histologic, and Rheologic
Slow flow
Capillary (CM)
Telangiectases
Lymphatic (LM) – macro or microcystic
Venous (VM)
Fast flow::
Aortic aneurysm, coarctation, ectasia, stenosis
Arteriovenous fistulas (AVF)
Arteriovenous malformations (AVM)
 Subcategorized based on predominant channel type and flow characteristics:
o slow flow = capillary and telangiectases, lymphatic and venous
o fast flow = arterial and arteriovenous (these are hemodynamicaaly active and
typically exhibit thrill , bruit , pulsations and increased skin temp, they expand
with increased blood pressure and blood flow with collateral formation second
to trauma and attempts of surgery )
Histology
 Each of the four major subcategories of vascular malformation has a particular
histopathologic appearance.
 Flat, quiescent lining endothelium is characteristic of all vascular malformations.
 Normal basement membranes; and a normal number of mast cells
 None of the vascular malformations express immunohistochemical markers of
angiogenesis (VEGF and bFGF) or type IV collagenase.
 Structurally abnormal vessels undergo progressive ectasia.
Capillary malformation
o comprised of uniform, ectatic, thin-walled capillary-to-venular–sized channels
located in the papillary and upper reticular dermis.
o Deficient perivascular neural elements may account for the altered neural
modulation of vascular tone and progressive ectasia that characterize these
anomalies.
Lymphatic malformation
o walls of variable thickness, comprised of both striated and smooth muscle,
with nodular collections of lymphocytes in the connective tissue stroma.
o filled with a proteinaceous fluid and do not have connections to the normal
lymphatic system.
o Lesions can be both macrocystic and microcystic, thoracic lesions usually
being macrocystic, and the more common cervicofacial lesions microcystic
Venous malformation
o thin walled with irregular islands of smooth muscle.
o Pale acidophilic fluid is typically seen within the channels and sacs of an LM,
whereas blood, fresh and organizing thrombi, and phleboliths characterize
VM.
o The dysplastic venous networks drain to adjacent veins, many of which are
varicose and deficient of valves.
Combined lymphaticovenous malformation (LVM)
o occurs particularly in the craniofacial region;
o microscopic thromboses also are seen in these combined slow-flow anomalies.
AVM
o The arteries in AVM are dysplastic, consisting of thickened fibromuscular
walls, fragmented elastic lamina, and fibrotic stroma.
o veins in an immature AVM appear “arterialized” (reactive muscular
hyperplasia), whereas in a mature AVM, the veins evidence degenerative
fibrosis and muscular atrophy.
The differentiation between malformations and hemangiomas
Clinical
 Hemangioma
o usually not seen at birth
o characterized by a rapid post natal growth phase and slow involution
stage
o M:F 1:3
 Cutaneous vascular malformation
o present at birth
o grow proportionately with the child and may expand rapidly secondary to
infection, trauma, hormonal changes
o M=F
Histology
 hemangioma - composed of plump rapidly dividing endothelial cells, hyperplasia
and increased mast cells
 Vascular malformations - no evidence of cellular hyperplasia but progressive
ectasia of structurally abnormal vessels with the malformed channels being lined
by a flat quiescent endothelium lying in a thin walled basal lamina and the
endothelium from malformations is difficult to culture in tissue media (poor rate
of cellular growth) unlike the hemangiomas
Haematology
 Large hemangioma can cause platelet trapping, shortened platelet half life and
profound thrombocytopaenia and may evidence a consumptive coagulopathy but
probably a secondary phenomenon
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Vascular malformations especially venous type can cause a true intravascular
coagulation defect with only mild thrombocytopenia and slightly decreased
platelet survival
Radiographic differences
 Angiogram of hemangioma shows well circumscribed mass of intense prolonged
tissue staining that is usually organized into a lobular pattern with feeding
arteries forming an equatorial network at the perimeter
 Vascular malformations are diffuse lesions consisting entirely of vessels without
paranchymal staining
 the angiogram pattern depends on the vessel type
Skeletal changes
 Vascular malformations tend to show an associated skeletal hypertrophy
Investigations
Mainstay is radiology
 can be used to diagnose; however, more often it is employed to specify a vascular
malformation’s rheologic nature and anatomic extent.
Ultrasound
 most cost-effective imaging modality and should be considered first.
 U/S and color Doppler study differentiate slow-flow from fast-flow anomalies,
and a discrete tumor mass(hemangioma) from diffuse anomalous channels in soft
tissue.
 Disadvantages: highly operator dependent and it is limited in delineation of the
anomaly’s size and its relationship to adjacent structures.
Magnetic resonance imaging
 provides the most informative portrayal of anomalous channels, their flow
characteristics, and extent of involvement of tissue planes.
 CM is not seen by MRI, except as minor skin thickening.
 VM is isointense to muscle on T1-weighted images and gives a high signal
intensity on T2-weighted sequences, a brighter signal than fat. Phleboliths,
pathognomonic of a venous anomaly, are seen as discrete, round signal voids on
T1- and T2-weighted spin-echo and gradient images.
 difficult to distinguish LM versus VM or LVM; these are better delineated by
administration of intravenous gadolinium and repetition of the T1-weighted
sequence. VM enhances inhomogeneously, whereas LM shows either rim
enhancement or no enhancement.
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MRI of an AVM demonstrates a myriad of flow voids on all sequences and highflow vessels on gradient sequences, contrast enhancement with gadolinium, and
usually no discrete parenchymatous signal abnormality.
Magnetic resonance angiography (MRA) and venography (MRV) show major
vascular channels without injection of contrast medium. These techniques are
useful to display fast-flow anomalies and abnormalities of major veins in patients
with complex-combined vascular lesions.
Contrast-enhanced computed tomography
 differentiates the various pure and combined slow-flow and fast-flow
malformations.
 Phleboliths are more clearly shown by CT than by MRI. Nevertheless, MRI has
supplanted CT for study of vascular anomalies. MRI is more accurate, does not
involve radiation, and has multiplanar capability.
 CT retains a place in evaluating intraosseous vascular malformations and
secondary bony changes.
Arteriography
 the most invasive technique, is rarely used solely for diagnosis.
 Usually done either in conjunction with superselective embolization as primary
treatment of AVF, palliation of AVM, or in preparation for surgical extirpation of
an arterial malformation.
Venous angiography (phlebography)
 still used in evaluation and treatment of certain venous anomalies of the limbs
 Slow-flow malformations are best studied at the time of sclerotherapy by
angiographic filming obtained by direct cannulation and injection of the lesion.
Capillary Malformation (“Port-Wine Stain”) (PWS)
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Capillary malformation is a macular, red vascular stain that is obvious at birth and
persists throughout life.
CM can be localized or extensive, on the face, trunk, or limbs.
Differentiated from the common fading macular stain (nevus flammeus neonatorum)
that occurs in 50% of neonates, commonly located on the glabella, eyelids, nose,
upper lip (“angel kiss”), and nuchal area (“stork bite”).
.
Incidence of Port wine stains
 0.3 % of newborns with skin discolouration
 usually evident at birth though may not be due to neonatal anaemia
 M=F
Distribution
 45 % of facial PWS are restricted to one of the three CN V distributions
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55% overlap distributions , cross the midline or are bilateral
mucous membranes are often involved contiguously
Clinical
 Flat and sharply demarcated and grows proportionately with the child and the color
ranges from pale pink or deep red or blue when the child cries , has a fever or in
warm environment.
 The pink flush darkens during age to a purple colour during middle age
 Facial CMs are prone to darken in color and likely to develop hyperplastic skin
changes.
 Thickened purple nodules can manifest in adolescence
 pyogenic granuloma can appear at any age over the lesion
 Curiously, these skin changes occur very rarely in CM of the trunk or limbs.
 Facial CM is sometimes associated with hypertrophy of soft tissues and underlying
skeleton. Lips and gums enlarge in the areas of capillary stain.
 Maxillary or mandibular overgrowth produces skeletal asymmetry.
 Extensive CM of a limb is associated with axial and transverse hypertrophy, often
present at birth.
 Venous varicosities do not develop during childhood, and limb hypertrophy, if
present, usually does not worsen as the child grows
Histology
 Ectatic capillary to venular sized channels within the papillary and upper reticular
dermis, with thin walled vessels lined with flat mature endothelium with
undetectable cellular turnover
Associated conditions
 Most CMs are harmless cutaneous birthmarks, but some are red flags that signal
underlying abnormalities
1) Sturge-Weber syndrome
 comprised of facial CM in association with ipsilateral pial and ocular
vascular anomalies.
 Proposed that it is an error in morphogenesis within a specific region of
the cephalic neural crest, giving rise to the abnormal vasculature in the
upper facial dermis and the pia arachnoid
 The leptomeningeal vascular abnormalities can cause seizures,
contralateral hemiplegia, and variable developmental delay of motor and
cognitive skills.
 There is a 45 % chance of the child having glaucoma and important for
early diagnosis to prevent permanent changes in the eye
 All children with port wine stain of the eyelid undergo early
ophthalmologic review
 The capillary stain involving the ophthalmic (V1) trigeminal dermatome
or extending into the others from VI are at risk of having intracranial and
ophthalmic complications
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Patients with either maxillary (V2) or mandibular (V3) CM alone are at
very low risk of having brain anomalies.
Radioisotope techniques, that is, single-photon emission tomography
(SPECT) and positron emission tomography (PET), are used for early
detection of the intracranial vascular anomalies in Sturge-Weber
syndrome.
MRI is more sensitive than CT in revealing pial vascular abnormalities
(i.e., CM, VM, arteriovenous fistula [AVF], and AVM), cerebral atrophy,
and prominent cortical sulci.
Gyriform calcifications of the outer layers of the cerebral cortex are seen,
typically in the temporal and occipital lobes; these changes are probably
secondary to the anomalous circulation.
Children who evidence ipsilateral increased choroidal vascularity are at
risk for retinal detachment, glaucoma, and blindness, more likely if the
CM involves both V1 and V2 neurosensory areas.
Glaucoma must be detected early before irreversible ocular damage
occurs. Fundoscopic examination and tonometry should be performed
biannually for 2 years and yearly thereafter for the remainder of the
patient’s life.
2) Capillary malformations of the limb can be part of complex-combined vascular
anomalies, such as Klippel-Trénaunay and Parkes Weber syndromes.
3) Midline cephalic CM can indicate an underlying occipital encephalocoele.
4) Dorsal CM can signal underlying cervical or lumbosacral spinal dysraphism.
5) Capillary malformation combined with pigmented nevus (more common in black
and Japanese infants) is called phacomatosis pigmentovascularis and suggests a
common defect in neural crest cell migration.
6) Cobbs syndrome - capillary stain of the posterior thorax is associated with a
underlying AV malformation
Treatment
 Treatment important to prevent trauma to child
 Left untreated 60 -70 % progress to cobblestoning ectasia which darkens the lesion
and promotes to bleeding
flashlamp pulsed dye laser
 Controversial whether results are better if treatment started in infancy and childhood.
o J Paedr 1993 - Lesions in patients less than 4 years of age were almost twice
as likely to clear than were those in older children (20% vs 12%), and in fewer
treatments (3.8 vs 6.5).
o Ann Plast Surg 1994 - children aged 3 to 8 years required the greatest number
of laser treatments
o NEJM 1998 - no evidence that treatment of port-wine stains with the flashlamp-pumped pulsed-dye laser in early childhood is more effective than
treatment at a later age.
 wavelength of 585 nm and a pulse width of 300-500 μs
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Significant lightening occurs in 70% to 80% of patients
Outcome is better in the facial area than in the trunk and the limbs.
Able to predict the outcome based on the amount of blanching achieved after the first
treatment with the best results seen in those that have significant blanching
Argon laser has been used but leads to more scarring- acceptable results are observed
in 30-40% of children
Photodynamic therapy (PRS June 1997)
 Using PsD-007 photosensitizer
 vascular lesions were irradiated less than half an hour after intravenous administration
of the photosensitizer.
 Overall, a 92% excellent or good lightening was seen after only one treatment
Surgery
 Role of surgery reserved for salvage
 Soft tissue and skeletal hypertrophy require surgical strategies.
 Contour resection for macrocheilia is very effective.
 Orthognathic correction is indicated for asymmetric vertical maxillary excess or for
mandibular prognathism.
 Excision of fibrovascular nodules is easily accomplished.
 In rare instances, it is necessary to excise an entire facial aesthetic unit(s) and to
resurface the area with a full thickness skin graft.
 Other treatments include tissue expansion to replace excised skin , SSG, over graft,
and (steroids, radiation and cryotherapy – these have poor response)
 Clodius (Ann Plast Surg 1986) - subtotal excision of the port-wine stain, retaining the
dermal base and covering the defects with full-thickness skin grafts.
Capillary-Lymphatic Malformations
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combined low flow dermal vascular anomalies( old term – hypertrophic nevus
flammeus, lymphangioma circumscriptum, hemangiolymphangioma)
Usually present at birth
Pink blue well demarcated areas located on the lower extremities/trunk
With trauma and infection the lesions become more keratotic and colour depends on
the amount of blood within the dermal channels
Treatment – local excision
Telangiectases
The telangiectatic disorders are discussed adjacent to the capillary anomalies considering
the caliber of vessels involved.
The telangiectases are pathogenically and clinically heterogeneous.
Cutis Marmorata Telangiectatica Congenita (Van Lohuizen Syndrome)
 This distinctive congenital condition consists of a reticulated, serpiginous,
depressed, blue-violet, cutaneous vascular network.
 Congenital ulceration and atrophy of the involved skin can be present.
 The lesions occur in either a localized or segmental distribution; rarely are they
generalized.
 The trunk and extremities are most commonly involved.
 Biopsy reveals dilated dermal capillaries and veins and sometimes thin-walled,
venous lakes in the subcutaneous layer. Thus, this peculiar vascular birthmark is
both capillary and venous.
 The condition improves, particularly over the first year of life; however,
cutaneous atrophy, vascular staining, and venous ectasia persist.
 This disorder should be differentiated from an accentuated pattern of normal
cutaneous vascularity called cutis marmorata or livedo reticularis.
Generalized Essential Telangiectasia
 Onset varies widely. Although lesions can appear before puberty, middle
adulthood is the usual age of presentation.
 Women are more commonly affected 2:1.
 The primary lesions are pin-sized, red-purple vascular puncta that appear in
groups, usually in the lower extremities.
 The lesions extend proximally and, over years, form gyrate or matted sheets of
telangiectasias.
 Flashlamp pulsed dye laser therapy is relatively effective.
Hereditary Hemorrhagic Telangiectasia (HHT; Rendu-Osler-Weber Syndrome)
 HTT occurs in 1 to 2 per 100,000 births and is a group of autosomal disorders of
similar phenotype caused by several genes and characterized by multisystem
vascular dysplasia and recurrent hemorrhage.
 Inheritance is autosomal dominant, and
penetrance is age-dependent, being 97
percent by the age of 40 years.
 mutation in a member of the TGF-β
receptor complex
 The homozygous form is probably
lethal.
 The pathogenesis involves structurally
weak vessels that become dilated,
elongated and tortuous as a result of
inadequate basal lamina and smooth
muscle elements
 The mechanism of bleeding is a local haemostatic abnormality perhaps related to
a plasminogen activator content resulting in elevated fibrinolysis in the
precapillary tissue
Clinical
 recurrent epistaxis, telangiectases elsewhere than the nasal mucosa, visceral
involvement, and a positive family history.
 recurrent hemorrhage from vascular lesions, especially in the nasal mucosa and
gastrointestinal tract, and from the presence of dermal, mucosal, and visceral
telangiectasia.
 The characteristic lesions are discrete, spider-like bright-red maculopapules,
typically 1 to 4 mm in diameter, located on the face, tongue, lips, nasal and oral
mucous membranes, conjunctiva, palmar aspect of the fingers, and nail beds.
 Lesions also occur on internal mucosal surfaces and in viscera.
 The telangiectasias can appear in childhood; however, they typically emerge after
puberty and increase in number with age.
 Epistaxis is the most common manifestation.
 Hematemesis, hematuria, or melena is also present and bleeding in the central
nervous system can cause neurologic symptoms.
 In certain forms of HHT, arteriovenous malformations develop, particularly in the
brain, spinal cord, liver, and lungs. Septic emboli from pulmonary AVMs
commonly cause brain abscess.
 10 to 15 percent mortality rate.
Ataxia-Telangiectasia (Louis-Bar Syndrome)
 Ataxia-telangiectasia is a neurovascular disorder of autosomal recessive
inheritance that appears at 3 to 6 years of life.
 progressive neurologic impairment, cerebellar ataxia, variable immunodeficiency
with susceptibility to sinopulmonary infections, impaired organ maturation, x-ray
hypersensitivity, ocular and cutaneous telangiectasia, and a predisposition to
malignancy.
Clinical
 Bright-red telangiectasis are first noted on the nasal and temporal area of the
bulbar conjunctiva and subsequently manifest on the face, neck, upper chest, and
flexor surfaces of the forearms.
 Cerebellar ataxia also begins in early childhood, followed by progressive
neuromotor degeneration.
 These patients have endocrine dysfunction, chromosomal instability,
immunologic deficiencies, and growth retardation.
 Death usually occurs in the second decade of life from recurrent sinopulmonary
infections and brochiectasia or from lymphoreticular malignancy.
 Heterozygous carriers of the gene also may be at significantly increased risk for
cancer; they are estimated to comprise approximately 0.5% to 1.5% of the normal
population.
Lymphatic Malformation
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Lymphatic malformation is composed of dysplastic vesicles or pouches filled with
lymphatic fluid.
Classification
 They can be described as either microcystic, macrocystic, or combined forms.
 The old terms are “lymphangioma” for microcystic LM and “cystic hygroma” for
macrocystic LM.
 Type I (cervicoaxillary)
 arise below the mylohyoid
 occur in the anterior and posterior triangles of the neck. These lesions
consist of large, thick-walled cysts with minimal infiltration of
surrounding tissues. Historically, they have been termed cystic hygromas.
 Type II(cervicofacial)
 located above the mylohyoid, commonly involving the tongue, floor of the
mouth, cheeks, lips, and sometimes the parotid gland.
Incidence
 M=F
 All races equal
 sporadic cases of lymphatic malformations are caused by de novo dominant
somatic mutations and that germline mutations are lethal
 Midline posterior cervical lymphatic cystic lesions (ranging from localized nuchal
fluid (12% risk of chromosomal abnormality), diffuse nuchal translucency (23%
risk), cystic hygroma (50% risk), and fetal hydrops (78% risk)) are often
associated with chromosomal abnormalities and usually diagnoses on prenatal
US- often fetal hydrops and significant association with Turners (45XO) and
trisomy- 13,18,21
Pathophysiology
 lymphatic system begins to develop at the end of the fifth week. Lymphatic
vessels develop as endothelial outgrowths from the venous system.
 First, 6 lymphatic sacs are formed. These lymph sacs sprout from large central
veins.
 Defect has been mapped to VEGF-R in some families.
Clinical
 LM never involutes; it expands or contracts depending on the ebb and flow of
lymphatic fluid and the occurrence of infection and bleeding.
 There are extremely rare examples of rapid, spontaneous deflation of macrocystic
cervicofacial lesions.
 Most LMs are evident at birth or detected before 2 years of age; however, they
can suddenly manifest in an older child and occasionally appear in adolescence or
adulthood. Prenatal ultrasonography can detect macrocystic LM as early as the
late first trimester of pregnancy.
 The characteristic history is enlargement commensurate with the growth of the
child
 rapid increase in size is seen in infection or bleeding; in the oral cavity (ie
tonguie) can cause speech difficulty, respiratory distress, dysphagia and sleep
apnea
 Anomalous dilated lymphatics in the skin or mucosa present as vesicles.
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Often intravesicular bleeding is evidenced as tiny, dark-red dome-shaped nodules.
Distribution
 Most common in the neck(75%), followed by the axillae(20%) and the pectoral
regions
 Airway obstruction is the most critical complication of cystic hygroma
occurring in the neck.
 In the head, the tongue, cheek and the floor of mouth are most commonly affected
 LM is the most common cause for macrocheilia, macroglossia, macrotia, and
macromelia
 LM of the upper eyelids, orbit and conj occur contiguously with involvement of
the frontotemporal skin and musculature. A characteristic feature of these is
exacerbation of exopthalmos with URTI
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LM in the cheek, forehead, and orbit is usually combined micro- and macrocystic,
causing facial asymmetry, distortion of features, and soft tissue and bony
hypertrophy.
Mandibular overgrowth manifests as malocclusion, typically anterior open bite
and class III occlusion12.
A bulky tongue, covered with vesicles, impairs speech and is complicated by
recurrent infection, swelling, bleeding, poor dental hygiene, and caries.
Micromacrocystic LM in the cervicofacial region can cause airway obstruction,
sometimes necessitating tracheostomy.
Cervicoaxillary LM commonly involves the thorax and mediastinum, causing
recurrent pleural and pericardial effusion.
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“Pure” craniofacial LM can be confused with VM. This occurs either because of
spontaneous intralesional bleeding or venous blood coursing through lymphatic
channels as a consequence of a subtotal surgical resection of LM. A third possible
diagnosis is primary combined LVM.
Extensive LM in an extremity is associated with lymphedema; another form is
distal, spongy subcutaneous LM with a large cystic reservoir in the groin.
Skeletal distortion and hypertrophy are also common features of limb LM. Pelvic
LM manifests perineal lymphangiectasias.
Visceral LM (old term “lymphangiomatosis”) can result in hypoalbuminemia
secondary to protein-losing enteropathy.
Prognosis
 A proportion of patients show spontaneous involution of the malformation and if
going to involute they do so by the age of 5.
 Those that involutes show much better aesthetic results. Thus those that show no
signs of spontaneous regression should be considered for excision
Treatment
Medical
 Sudden enlargement of an LM is usually the result of either intralesional bleeding
or cellulitis.
 Pain medication, rest, and time are all that are needed for the former.
 Any viral or bacterial infection can cause an LM to “flare up.” Antibiotics
and nonsteroidal anti-inflammatory drugs can be given during these episodes.
 Cellulitis in an LM requires immediate antibiotic therapy, and often prolonged
intravenous administration is necessary. Septicemia is life threatening.
Sclerosant therapy
 Large cysts can be treated with aspiration of lymphatic fluid and instillation of
sclerosant agents:
1. pure ethanol
2. sodium tetradecyl sulfate
 considered to be less toxic then absolute alcohol
3. bleomycin
 disadvantages: toxicity (pulmonary fibrosis); scarring making
surgical dissection more difficult.
4. OK-432 (group A Streptococcus type 3 treated with benzylpenicillin).
 inject into the lesion at a few sites until the lesion expands slightly.
 dose of OK-432 is adjusted depending on the size of the
lymphangioma, but does not exceed 0.2 mg of OK-432 in one
injection.
 Another injection is given around 6 weeks after the treatment;
when shrinkage of the lesion is judged insufficient around 5 weeks
after the treatment.
 induces sclerosis via host-mediated inflammation
 Advantage is less scarring than other sclerosants
 Results of sclerosants are much better if used as primary modality or presurgery
and worse if used after surgery
 Macrocystic lesions are more likely to respond than microcystic lesions.
 swelling is common after sclerotherapy for LM - can be a risk of compression by
surrounding vital organs such as the trachea, SVC
 thus important to monitor patients for compartment syndrome and neurological
deficits after the procedure. Airway protection is also mandatory when a lesion
involving the airway is treated with sclerotherapy. Skin blistering is a common
occurrence and may result in scarring.
 Sclerotherapy may be contraindicated in the following situations:
1. Patient is allergic to the sclerosant or contrast media.
2. Patient has a cardiac condition.
3. Bleeding cannot be controlled.
4. Systemic leak of the sclerosant cannot be avoided.
5. Significant skin or mucosal injury is expected.
6. Postinjection swelling puts another organ at risk (eg, injury to the optic
nerve).
7. Postinjection airway swelling cannot be managed by a tracheal tube or
tracheostomy
Surgery
 surgical excision with careful preservation of involved neurovascular structures
has been considered the treatment of choice.
 Resection is the only way to “cure” an LM. Surgical guidelines are:
1. focus on a defined anatomic region;
2. 2 define the duration of the procedure;
3. 3 limit the acceptable blood loss; and
4. 4 perform as thorough a resection as possible, given anatomic restrictions.
 lymphatic malformations do not invade surrounding tissue but involves
surrounding tissue that appears normal thus a wide local excision is
recommended.
 Surgery should be delayed until about 2 when structures are more easily
identifiable
 Most have stable airways and foodways and can be observed
 Cervicoaxillary lesions
1. ideally resected as a single procedure. Repeat excision is complicated by
fibrosis and distorted tissue planes. Optimal timing is age 1-2 years, if
symptoms permit.
2. median sternotomy may be needed to excise a mediastinal component.
 Cervicofacial lesions
1. difficult management issue secondary to their infiltrating nature
2. as histologically benign, complete excision is often unnecessary and may
be harmful.
3. Optimizing and preserving function are the primary objectives
4. Thus surgical procedures often are limited in scope and frequently are
staged according to anatomic areas
5. Macroglossia often requires operative reduction
6. Osteotomy/ostectomy is indicated for the abnormal maxillary/mandibular
relationship associated with cervicofacial LM.
 Approaches
1. Frontoorbital LM- use coronal incision for access
2. Cervical – radical neck type dissection is required with IJV usually
requiring excision
3. Hemificial LM – preauricular incision with dissection of the facial nerve
 Complications
1. postoperative complications include neurovascular injury, prolonged
serous drainage, hematoma, cellulitis, chylous fistula, chlothorax
2. Recurrence (10%) - Transected lymphatic channels regenerate after
subtotal excision. Thus, warty vesicles can appear in the operative scar
and the soft tissue mass can recur. Furthermore, deep cisterns are
numerous with microscopic communications, and, thus, expansion of
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persistent LM is commonly observed in the late postoperative period or
even years later.
Airway Obstruction
 Trachestomy if failure of conservative management to maintain airway
 Do not attempt drainage of the cyst because it increases the risk of
infection through possible contamination and causes increased difficulty
during resection because the thin walls of the cyst are not located easily
when not fluid filled.
Laser
 Treatment with CO2 or Nd:YAG laser is useful for unresectable lymphatic
malformations. The results are short lived thus repeated treatment is required.
 Especially useful for lymphangiomas affecting the tongue.
Cutaneous LM (“lymphangioma circumscriptum”)
 a small dermal lymphatic malformation.
 A subcutaneous lymphatic cistern communicates through dilated lymphatic
channels with superficial cutaneous vesicles.
 It often can be resected totally and the defect closed with a split-thickness skin
graft.
Venous Malformation
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Venous malformations are present at birth, but are not always evident.
These slow-flow anomalies manifest either as a faint blue patch or a soft blue
vascular mass.
They are localized or extensive within an anatomic region, minor or distorting, and
typically located on face, limbs, or trunk.
Venous malformations can occur in internal locations such as oronasopharynx,
bladder, brain, spinal cord, liver, spleen, lungs, skeletal muscles, and bones.
these anomalies often are incorrectly labeled “cavernous hemangioma.”
Distribution
 Usually VM is solitary; however, multiple cutaneous or visceral lesions occur and
they can be hereditary.
Associated conditions
1) Familial glomangiomatosis is a rather common autosomal dominant syndrome
of high penetrance, consisting of multiple, often tender, blue nodular dermal
venous lesions that can occur anywhere on the skin.
 Histologically, these differ from typical VM by the presence of numerous
glomus cells lining the ectatic venous channels.
2) Maffucci syndrome
o Venous malformations and multiple enchondromas.
o Symptoms occur by puberty. No sex predilection exists.
o Sporadic condition
3) Blue rubber bleb nevus (Bean syndrome)
o poradic combination of cutaneous and visceral VMs.
o skin lesions are soft, blue, and nodular; they can occur anywhere, but are
typically located on the hands and feet.
o The gastrointestinal lesions are sessile (submucosal-subserosal) or
polypoid, located in the esophagus, stomach, small and large bowel, and
mesentery. They are best seen by endoscopy rather than by MRI,
radionuclide scan, or arteriography.
o Recurrent intestinal bleeding can be severe, requiring repeated
transfusions.
Clinical
 Venous malformations are easily compressible and exhibit increased swelling
when dependent.
 Patients often complain of pain and stiffness in the area of the VM, especially on
awakening in the morning.
 Episodic thrombosis occurs; phleboliths can appear in patients as young as 2
years of age. VM grows proportionately to the child, expands slowly, and often
enlarges during puberty.
 Craniofacial VM is usually unilateral. A mass effect commonly causes facial
asymmetry and progressive distortion of facial features.
 Oral VM typically causes dental malalignment and open-bite deformity.
 Intraorbital VM induces expansion of the orbital cavity. The result can be
enophthalmia when the patient stands and exophthalmia when the head is
dependent.
 Orbital VM can communicate through the sphenomaxillary fissure with VM of
the infratemporal fossa and cheek.
 Buccal VM typically involves the tongue, palate, and oropharynx, but rarely
impairs speech. Pharyngeal and laryngeal VM commonly progress to obstructive
sleep apnea. VM in an extremity can involve skin only, or extend into muscles,
joints, and bone. An extremity VM rarely produces length discrepancy, although
lower limb lesions can cause slight undergrowth as a result of disuse.
 Limb VM sometimes causes structural weakening of the bony shaft and
pathologic fracture.
 VM in the synovia of the knee often results in episodic attacks of joint pain due to
bloody effusion. Hemarthrosis is particularly troublesome in children with VMassociated coagulopathy.
 Magnetic resonance imaging is the most informative imaging technique. A
coagulation profile should be done on any child with an extensive VM who is at
risk for localized intravascular coagulopathy (LIC).
 This coagulopathy is totally different from Kasabach-Merritt phenomenon. The
platelet count is minimally diminished, in the 100 to 150,000/mm3 range. Usually
prothrombin time and activated partial thromboplastin time are normal, fibrinogen
is low (150–200 mg/100 mL), and there are increased D-dimers.
Treatment
 Many venous malformations do not require specific management apart from
reassurance and an explanation.
 Treatment of a VM is indicated for appearance or for functional problems.
Sclerotherapy
 Based on the anatomy and pathophysiology of venous malformations, most
authorities advocate a trial of sclerotherapy, either alone or preceding attempted
surgical therapy.
 Small cutaneous VM in any location can be injected with a sclerosant, such as 1%
sodium tetradecyl sulfate. Alcohol yields a slightly decreased incidence of
recurrence with a marginally increased risk of systemic toxicity. OK 432 is not
used for this condition.
 A large VM, cutaneous or intramuscular, requires general anesthesia and “realtime” fluoroscopic monitoring during sclerotherapy. Absolute ethanol (100%) is
commonly used in the United States, whereas, Ethibloc (a mixture of zein, a corn
protein; alcohol; and contrast medium) is used in Europe.
 Sclerosis of a large VM is potentially dangerous and must be treated by a skilled
and experienced interventional radiologist.
 Compression and other maneuvers prevent passage of the sclerosing agent into
the systemic circulation.
 Local complications include blistering, full-thickness cutaneous necrosis, or
neural damage.
 Systemic complications include renal toxicity and cardiac arrest.
 Multiple sclerotherapeutic sessions may be necessary, often at several-month
intervals.
 Venous anomalies have a propensity for recanalization and recurrence.
Surgery
 Surgical resection is considered, after completion of sclerotherapy, to reduce
tissue mass for functional or cosmetic indications.
 Malocclusion requires orthodontic management and, if necessary, orthognathic
procedures after eruption of the secondary teeth.
 Elastic support stockings are indispensable for management of VM in the
extremities.
 Low-dose aspirin (80 mg qid or qid) seems to minimize the occurrence of
episodic, painful phlebothrombosis.
 Subtotal (contour) resection indicated where total surgical extirpation is difficult
and is performed to relieve pain, reduce bulk, or improve function.
 Intramuscular VM in the thigh or calf can diminish function and require resection.
 VMs of the gastrointestinal tract have been managed by banding via the
endoscope, sclerotherapy, and bowel resection.
 Argon laser and the YAG laser can be used to treat intraoral venous
malformations but repeated treatments may be necessary . it is a useful tool for
controlling symptoms
Venous malformation of skeletal muscle (PRS 2002 Mulliken)
Location
 Any muscle with masseter and the orbicularis oris being the most commonly
involved muscles
 The HN muscles are MCly involved followed by LL
Clinical
 Pain is most common symptom at rest and dependency and aggravated by
activity in some cases
 Bleeding (DIC) and skeletal complications may occur
Radiol
 MRI – isointense with surrounding muscle on T1 and hyper intense on T2 with
inhomogeneous enhancement after gadolinium due to intraluminal clot.
Phleboliths were seen as signal voids
 Arteriography – not routinely used but showed two characteristic features on the
late phase images
1. slight enlargement of muscular arterial branches and tiny sinusoidal spaces
often at the periphery of the mass with the conducting veins filling last
2. late filling of the conducting veins that compose the venous malformation
 Venography – performed at the time of sclerRX
Histopath
 Small medium sized thin walled vascular channels with flat endothelium and
irregular muscle walls with appearance of dysplastic veins
 Lumen contained phleboliths or organized thrombi with papillary fronds (
mansons papillary endothelial hyperplasia)
 vascular channel infiltrating the skeletal muscle
Clinical
 More common in women
 Many are asymptomatic
 Hormonally modulated with changes in menses , preg and anticonvulsant meds
 Extensive lesions can cause bleeding and DIC
Treatment
1. compressive garments and aspirin to inhibit the thrombotic episodes is all that is
required for many
2. sclerotherapy – initial treatment for all but the very localized lesions and controls the
pain and swelling with minimal collateral damage. It involves direct precut
cannulation of 100% ethanol, 3% tertradecl sulphate or 5% ethanolamine oleate. The
sclerosant damages the endothelial cells causing thrombosis and fibrosis.
Recanalization can occur requiring further treatment
3. surgical excision – best for venous malformations that are localized to one muscle
group, those with thrombosis , those in specialized muscle groups (intrinsics of hand)
those causing neurological symptoms or compression syndrome
a. aim for resection of all of the muscle tendon unit and partial resection is
avoided
4. in certain areas ie the lips the lesions are toughened with sclerotherapy followed by
contour resection
Arteriovenous Malformation
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Most fast-flow malformations in children are AVMs.
Pure arterial malformations (AM), for example, aneurysm, ectasia, or stenosis, rarely
occur as isolated symptomatic abnormalities; however, they can be associated with
AVM.
The epicenter of an AVM is called the nidus and consists of arterial feeders, microand macroarteriovenous fistulas (AVFs), and enlarged veins.
AVM is present at birth and can either manifest in infancy, or appear later.
Intracranial AVM is more common than extracranial AVM, followed in
frequency by AVM of the limbs, trunk, and viscera.
Cervicofacial involvement is most common in the cheeks, ears, nose, and forehead,
in descending order of prevalence.
Arteriovenous malformation is often underappraised in childhood.
AVM’s blush can be mistaken for hemangioma or “port-wine stain”.
Puberty, pregnanacy(hormonal modulations) and trauma appear to trigger expansion,
resulting in cutaneous signs of a fast-flow nature.
These high flow lesions are hemodynamically active with pulsations bruits increased
temp and expand with alterations of pressure or flow and with collateral formation
secondary to trauma or attempts at excision
These high flow lesions are likely to cause destruction of adjacent skeletal
structures unlike low flow lesions that cause skeletal hypertrophy
Primary skeletal involvement occurrs only in the tooth-bearing bones-invariably
expanded by the malformation. These malformations are often "silent," particularly in
absence of overlying tissue involvement, their presence found dramatically at the time
of dental extraction. This pattern has been noted previously, and a loose tooth in a
bleeding socket should be treated with extreme caution.
Secondary bony involvement in the cranium manifested as erosion or indentation of
outer cortex and corresponded to the path of dilated draining veins. This secondarily
involved bone does not need to be excised, although contouring may be indicated
Pathogenesis
Theories
1) failure of regression of arteriovenous channels in the primitive retiform plexus.
a. These primal arteriovenous communications persist, but some may not
canalize or conduct blood flow for many years. Expansion is the result of
increased blood flow through the malformation and dilation of adjacent
arteries and veins (collateralization and recruitment).
2) Local ischaemia
a. well known that an arteriovenous malformation enlarges rapidly following
proximal ligation.
b. enlargement after trauma postulated to be caused by ischemia. Steal
phenomenon may produce localized ischemia and resultant pain and
ulceration.
c. In a complementary way, Hurwitz proposed that the failure of enlargement of
residual malformation after microvascular tissue transfer may be a result of
enhanced vascularity of the reconstructed field.
Clinical
 The skin becomes a red or purple color, a mass appears beneath the vascular stain,
and local warmth, a thrill, and a bruit are present.
 Whatever the AVM’s location, the eventual consequences are ischemic skin
changes, ulceration, intractable pain, and intermittent bleeding.
 Pseudo-Kaposi sarcomatous skin changes, scaling violaceous plaques, commonly
overlie an AVM in the lower limb.
 An extensive AVM, usually involving an entire limb or the pelvis, can cause
increased cardiac output.
 Clinical diagnosis is confirmed by ultrasonography and color Doppler
examination.
Classification
clinical staging system of Schobinger:
Stage I: quiescence
 Blush/stain, warmth, and AV shunting by continuous Doppler or 20 MHz color
Doppler (visible)
Stage II:expansion
 Same as stage I, plus palpable nodule, enlargement, tortuous tense veins, pulsations,
thrill, and bruit (palpable)
Stage III: destruction
 Same as above, plus either dystrophic changes, ulceration, bleeding, persistent
pain, or destruction (painful)
Stage IV: decompensation
 Same as Stage III, plus cardiac failure (life threatening)
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Pulsed Doppler quantitates arterial output (compared to the normal side) and can be
used to follow the progression of an AVM.
MRI best documents the extent of the malformation.
Angiography is unnecessary until intervention is considered.
o Angiography usually shows a high degree of shunting with a high blood flow
through the lesion.
o A number of microshunts are not demonstrated on arteriograms but become
apparent a short time after ligation, incomplete embolization, or partial
resection because of reorientation in blood supply and altered hemodynamics.
Natural History
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The natural evolution of these malformations provides guidelines for prognosis and
urgency of intervention.
An arteriovenous malformation can remain stable for years in stage I.
A bruit is of little significance unless its intensity is increasing.
in general, once pain, bleeding, or ulceration has been established, progression of
the AVM is inevitable unless the lesion can be resected.
An important question remains to be answered: should we intervene in stage I before
it progresses to stages II and III, becoming more difficult to treat? This approach may
be advisable in certain circumstances, such as in children with discrete lesions on the
scalp or lip. A more definitive answer requires further study of the likelihood of
progression of stage I to stage II.
Puberty seems to provoke rapid progression of some arteriovenous malformations.
Previous reports underscore that pregnancy may provoke progression.
Malformations affected by pregnancy behaved aggressively.
Pregnancy, therefore, represents a definite risk in women with a late-onset
arteriovenous malformation.
Treatment
 Usually AVM is latent during infancy and childhood.
 Once the diagnostic workup is complete, the child is carefully followed.
 Early embolic/surgical management of a silent AVM is debatable, but should be
considered if resection is easily achievable.
 Conventionally, AVM is treated whenever endangering signs and symptoms arise:
ischemic pain, recalcitrant skin ulceration, bleeding, or increased cardiac output
(Schobinger stage III–IV).
 For small lesions, excision alone may be possible. For more extensive lesions, the
treatment of choice is combination therapy that consists of preoperative
angiography with selective embolization followed by definitive resection within
24-48 hours.
 If surgery delayed longer than 48 hours, AVM may undergo rapid expansion
 Ligation or proximal embolization of arterial feeding vessels must never be done!
This causes rapid recruitment of flow from nearby arterial vessels to supply the nidus.
Furthermore, arterial ligation limits access for arterial embolization.
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Superselective arterial embolization can be palliative, that is, for pain, bleeding, or
cardiac failure, particularly in those instances in which surgical excision would result
in mutilation or disfigurement.
Palliative embolization controls an AVM for a time; it cannot cure an AVM
Direct puncture of the nidus, in conjunction with local arterial and venous
compression, may be necessary if the arteries are dysplastic and tortuous, or if the
feeding arteries have been ligated.
Embolization or sclerotherapy minimizes intraoperative bleeding but does not
diminish the limits of resection.
The AVM nidus and usually the covering skin must be widely resected.
The overlying skin can be saved if it is normal; however, if it is deeply stained and
retained, recurrence is common. The principal question for the surgeon is how
extensive the resection must be.
Microvascular tissue transfer permits wide resection of malformation and optimizes
the vascularity of the region. Residual malformation adjacent to a free flap can remain
quiescent.
Examination of the earliest angiograms (before embolization) and MRI studies,
intraoperative use of the Doppler probe, and frozen sections of the margins are
helpful. However, it is the type of bleeding from the wound edges that gives the most
certain answer as to whether or not the resection margins are “clean.” Wound
coverage is performed, preferably at the same time, and microsurgical free flap
transfer is often needed for reconstruction.
After combined embolization/surgical resection, the patient must be followed for
years by clinical examination, ultrasonography, and/or MRI. .
Treatment with laser, steroids, or irradiation has not been effective.
Treatment Options
Indications for treatment(mulliken/Hansen).
(1) Early stage (I and II) lesions can be resected and reconstructed easily. Combined
embolization and resection successfully treated 7 out of 8 stage I malformations and will
prevent progression to larger, more recalcitrant lesions.
(2) Painful or rapidly enlarging lesions (stages II and III) warrant early intervention
owing to high probability of progression and risk of serious hemorrhage.
(3) Intervention for extensive stage I lesions remains controversial for three reasons:
(a) we cannot predict the risk of progression to later stages;
(b) the resection of very extensive stage I lesions is more likely to be incomplete
and hence cure rate may not conform to the figures published in this work; and
(c) the deformity produced by extensive resection and complex reconstruction of
the malformation may be worse than the original lesion.
Resection Margins
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complete excision of the nidus is critical.
Preoperative imaging studies are performed to define the limits and extent of the
nidus. Angiography demonstrates the nidus, its feeding vessels, and flow
characteristics. Magnetic resonance imaging shows the extent of soft-tissue
involvement, and computed tomography delineates bony involvement. The imaging
modalities overlap in the information they provide, and a composite mental picture of
the malformation should evolve. Newer imaging techniques (e.g., magnetic resonance
angiography and three-dimensional computer reconstruction) may enhance the
accuracy of preoperative planning.
Clinical judgment based on the pattern of tissue bleeding and intraoperative Doppler
are the best guides to the margins of resection. However, both are clearly dependent
on the experience of the surgeon.
Skin discolored by vascular stain is involved and should be excised; however, skin
with fine, scattered telangiectases can be preserved. Pre- or intraoperative assessment
may fail on occasion because the malformation is a field defect in which some of the
lesion is dormant or latent.
Frozen section and paraffin sections are unreliable. The distinction is made on the
basis of architectural features of the vessels, as no staining technique capable of
distinguishing between the arteriovenous malformation nidus and recruited collateral
vessels exists.
Compartmentalisation (PRS 2005 Ian Jackson)
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For massive malformations resistant to conservative treatment or failed
conventional surgery
Indications
1. as primary therapy for patients with massive high-flow and low-flow vascular
malformations not responsive to embolization and unsuitable for surgical
resection (Popescu)
o may result in fibrosis and it may prevent significant bleeding episodes
and enlargement of the lesion. It may even allow staged resection of a
massive vascular lesion.
2. as an adjunct for excisional surgery to control bleeding
3. to stop the sudden onset of uncontrollable bleeding from a high-flow or lowflow vascular malformation in an emergency situation.
o Allows use of high doses of sclerosant agents which would be
otherwise ineffective or hazardous in high flow lesions.
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patient should be informed as to the possibility of resection and the necessity of
abandoning the procedure. They should also know that there is a high risk of
damaging the facial nerve, of losing skin, of hematoma, and of infection.
In highly selected patients, cardiopulmonary bypass might be considered provides excision with reduced blood loss, with the lowest possible flow
conditions to protect vital organs from injury
o High bleeding risk persists due to
1. bleeding during rewarming phase
2. intraoperative heparinization
3. hypocoagulability state worsens because the cardiopulmonary
bypass pump traumatizes platelets and erythrocytes
When faced with massive bleeding during resection of a large vascular
malformation, the compartmentalization technique has been used to control this
in both high-flow and low-flow lesions
These sutures interrupt the blood supply from the regional vascular network and
divide the vascular malformation into compartments.
This technique requires the use of large, curved needles and strong nonabsorbable
suture material that will not cut out easily.
Taking deep bites into the lesion including the underlying normal tissue is
mandatory to achieve an effective result. An attempt is made to establish blocks
of tissue in which the flow is considerably reduced.
After this, a large dose of the sclerosant agent is injected into each compartment.
Complex-Combined Vascular Malformations
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The complex-combined type vascular malformations include CVM, CLM,
CLVM, and CLAVM. They are often associated with soft tissue and skeletal
hypertrophy.
These composite forms are difficult to designate by light microscopy.
Eponyms have been used to describe these disorders, but these proper names
should be relinquished because they are often misused and misleading, and
indicate nothing of pathogenesis.
Until the mechanism is understood, there is a simple nosology using acronyms,
based on flow characteristics and dysmorphic channel architecture.
Like the “pure” vascular malformations, complex-combined anomalies can be
categorized as either slow flow or fast flow
Slow-Flow Complex-Combined Malformations
 Klippel-Trenaunay syndrome (CLVM) is a well-worn eponym for a type of
combined slow-flow anomaly associated with limb hypertrophy.
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The CMs are multiple, usually studded with hemolymphatic vesicles (CLM), and
typically located in a geographic pattern on the anteriolateral aspect of the thigh,
buttock, or trunk.
Anomalous lateral veins are prominent because of insufficient to absent valves;
deep vein anomalies also occur.
Lymphatic hypoplasia is another primary defect. Limb hypertrophy can be minor
to grotesque. A few patients with classic Klippel-Trenaunay syndrome have a
short or hypotrophic limb.
Proteus syndrome is a sporadic vascular, skeletal, and soft tissue disorder
characterized by asymmetric growth. Subcutaneous tumor-like anomalies are
comprised of connective tissue, adipose tissue (lipomas and aggressive
lipomatosis), Schwann cell structures, and vascular tissue.
There is a predilection for the thorax and upper abdomen. The vascular anomalies
are of the CM, LM, CVM, and CLVM type.
Macrocephaly (calvarial hyperostoses); asymmetry of the limbs; partial gigantism
of the hands or feet, or both; and curious cerebriform plantar thickening
(“moccasin” feet) can be present. Verrucous (linear) nevus also occurs; thus,
Proteus syndrome may be on a spectrum with epidermal nevus (Solomon)
syndrome. Clinical features suggest that Proteus syndrome results from a
dominant lethal gene that survives by somatic mosaicism.
Maffucci syndrome denotes the coexistence of exophytic vascular anomalies with
bony exostoses and enchondromatoses. The vascular lesions are complex venous
in type; they can occur in the subcutaneous tissue, bones (particularly the limbs),
the leptomeninges, or the gastrointestinal tract. Malignant degeneration, usually
chondrosarcoma, occurs in 20% to 30% of patients.
Fast-Flow Complex-Combined Anomalies
These anomalies are uncommon. The acronyms CAVM, CAVF, or CLAVM correspond
to the old term Parkes Weber syndrome.
Cutaneous warmth, bruit, and thrill are pathognomonic. MRI or arteriography in young
children usually shows only diffuse hypervascularity of the limb; multiple AVFs become
obvious later, occurring throughout the affected limb, particularly near the joints.
Treatment
These children should be seen annually.
By age 2 years, clinical evaluation is made and leg length is radiologically measured.
If the length discrepancy is more than 1.5 cm, a shoe lift is prescribed to prevent limping
and secondary scoliosis.
For fast-flow combined anomalies, ultrasonography and color Doppler evaluation of
limb arterial and venous vessels are indicated when the child is 3 to 4 years old.
In contrast to pure limb VM, the muscles and joints are rarely involved; however, MR
angiography and MR venography are useful to detect arterial feeders, document the
anomalous veins, and determine whether or not the deep venous system is functional.
Management is fundamentally conservative. An elastic compressive stocking is
recommended for a limb with venous insufficiency and a functioning deep system.
Superficial varicose veins are rarely treated surgically unless they are grossly
incompetent, the deep venous system is functional, and the patient has significant
symptoms, for example, leg fatigue, heaviness, or inability to wear shoes because of
enlarged dorsal veins. It is unnecessary to correct for length differential in the upper
limbs. In contrast, percutaneous epiphysiodesis is needed if there is a 2 cm or more
differential in leg length.
Staged surgical contour resection or selective amputation is needed for grotesque
hypertrophy that prevents fitting of shoes or interferes with ambulation. Circumferential
thoracic CLVM can be resected in stages. Postoperative healing is often problematic after
resection of CLVM in any location.
Episodic bleeding from capillary-lymphatic (CLM) skin vesicles is annoying. Elastic
support helps by compressing the dilated underlying veins and provides protection from
abrasion of the skin. Sclerosis of the vesicles with 1% sodium tetradecyl sulfate can be
effective. If bleeding persists, excision of the abnormal vascular plaque and replacement
with split-thickness skin graft give long-term control.
.