Definition
Abnormal protrusion of the contents of a cavity through a
weakness in its containing wall
Aetiology
Congenital
Persistent processus vaginalis (inguinal)
Persistent umbilical opening
Hernias
Types of hernias
>75% Inguinal hernia
<10% femoral hernia
Umbilical hernia
Periumbilical hernia
Incisional hernia
Spigelian hernia
Obturator hernia
Acquired
Weakened abdo wall
Ageing
Previous surgery (incisional hernia)
Steroid use
Post-op surg site infection
Smoking
Increased intraabdo pressure
Pregnancy
Obesity
Ascites
Chronic cough
Heavy lifting
Contents of a hernia
Peritoneal lining
Omentum and/ or bowel
Unusual hernia types
Richter’s hernia—only part of the bowel circumference is
trapped within the hernial sac. As a result, there is a partial
bowel obstruction with vomiting but the patient continues to
pass flatus (below)
Characteristics
Reducible—contents re-enter containing cavity (usually the
abdomen) either spontaneously or with manipulation
Irreducible/ incarcerated—hernia persists despite manipulation
May be due to narrow hernia neck
Small defects are more dangerous than large defects
At risk of strangulation
Obstructed
Kinked bowel à obstruction ± strangulation of bowel
segment
Strangulated
Ischaemia of the bowel within the incarcerated/
obstructed hernia
Decreased lymphatic flowà↑venous pressure à↑
bowel oedemaà impeded arterial inflowà infarction
Sliding hernia—retroperitoneal structure such as the colon or
urinary bladder slides down and forms the wall of the hernial
sac
Pantaloon hernia—both a direct and indirect hernia occurring
together
Inguinal hernia
Epidemiology
M>F 12:1
2 peaks in incidence
Congenital <5yo
Acquired >50yo
Location
Above and medial to the pubic tubercle
Anatomy
Inguinal canal = deep ring + superficial ring
Inguinal lig runs from ASIS to pubic tubercle
Deep inguinal ring
Formed through transversalis fascia
Lies 1-2cm above midpoint of inguinal lig
Superficial inguinal ring
Formed through a v-shaped defect in external oblique aponeurosis
Lies above and medial to pubic tubercle
Types of inguinal hernia
Direct: medial to the inferior epigastric artery
Protrude anteriorly through transversalis fascia (Hasselbach’s
triangle)
Indirect: lateral to the inferior epigastric artery
In the inguinal canal descending to the scrotum
Leaves the abdo via deep inguinal ring to follow an
oblique course through the inguinal canal
Peritoneal sac may represent a patent or reopened
processus vaginalis
May extend to the tunica vaginalis surrounding the testis
Pantaloon: combination of the both
Hasselbach’s triangle
Inferior: inguinal lig
Lateral: inferior epigastric artery
Medial: rectal sheath
Inguinal canal
Anterior wall: external oblique aponeurosis covers entire canal and internal
oblique covers lateral 1/3
Posterior wall: conjoint tendon medially, transversalis fascia entire canal
Superior wall: internal oblique and transversus abdominis (conjoint muscle
Inferior wall: inguinal lig
Contents: 3433
3 vessels: testicular artery and vein, artery and vein to vas,
cremasteric artery and vein
4 nerves: n to cremaster, sympathetic n, ilioinguinal n, genital
branch of genitofemoral n
3 fasciae: external spermatic fascia, cremasteric fascia, internal
spermatic fascia
3 others: spermatic cord, vas deferens, lymphatics
Clinical features
Lump, usually not symptomatic until exacerbated by any
condition that ↑intraabdo pressure
Chronic cough
Obesity
Constipation
When exacerbated, cause dragging/ aching sensation
Operative management
Congenital inguinal repair should be done asap due to
increased risk of incarceration, strangulation and testicular
ischaemia
Symptomatic adult hernias should be repaired
Indirect inguinal hernia
Usually asymptomatic in the morning then symptoms develop
throughout the day as the hernia moves down the canal
If deep ring defect, it behaves like a direct hernia
Direct inguinal hernia
Abdo wall lump appears immediately on standing
Diagnosis
Clinical exam
Remember to stand the patient
Presence of cough impulse
Reduction into its opening defect
Once reduced, location of deep ring can be determined
USS/ CT if equivocal dx/ obstruction suspected
Differentiation of direct vs indirect often done intraoperatively
Conservative management for elderly with significant
morbidities
Open inguinal hernia repair
Day case, but admission for complications
5cm incision in groin area
Intestines are placed into their correct position by excising the
hernial sac near the spermatic cord and repairing the weak
area
The weak area is then strengthened with a synthetic mesh
(tension free lichtenstein repair)
Post op care
Patient should not drive or operate machinery for 24h
Routinely, patient will be prescribed painkillers but not abx
Avoid heavy lifting for 6-8 weeks
Epidemiology
F>M
30% of all hernia repairs in women and <15 of all hernia
repairs in men
More common >70yo
Location
Below and lateral to pubic tubercle
Lap herniorrhaphy
Indications: bilateral hernias, recurrent hernias
Both techniques listed below require the use of mesh and are
considered tension free repairs
Totally extraperitoneal repair
Transabdominal preperitoneal patch repair
Complications of repair
Scrotal haematoma
Wound infection
Urinary retention
Chronic pain/ paraesthesia in the scrotum (labium majora in females) from
damage to the ilio-inguinal nerve
Testicular atrophy caused by inadvertent damage to the testicular artery
Recurrence
<1% rate
Due to poor operative technique
Conditions like chronic cough, constipation or bladder outlet
obstruction also contribute to recurrence
Risks of procedure
General risks of surgery and GA: N/V, sore throat, cardiac,
resp, DVT/ PE risks depending on comorbidities
Risks specific to procedure
Damage to blood vesselsà bleeding, haematoma
(require repeat operation)
Testicular atrophy (<1%) when testicular artery is
damaged
Infection of the wound or mesh (abx, removal of mesh if
infected)
Nerve damage à chronic pain in groin that may resolve
after the operation but may persist
Recurrence (1%)
Femoral hernia
Anatomy
Femoral △
Superior: inguinal lig
Lateral: medial border of sartorius muscle
Medial: medial border of adductor longus
Floor: iliacus, psoas, pectineus, adductor longus
Roof: superficial fascia, great saphenous vein
Contents: (VAN medial to lateral) fem vein, fem artery, fem n
Clinical features
Small lump immediately below the inguinal lig and just lateral
to its medial attachment to the pubic tubercle
Cough impulse rarely detected due to narrow neck of hernial
sac
Due to narrow neck, more likely to strangulate but
localising signs usually absent
30% present with bowel obstruction
DDx
Fen canal lipoma
Saphena varix (SFJ varices)
Fem lymph node
Fem artery aneurysm
Fen artery pseudoaneurysm (post angiography)
Sarcoma (leio/ rhabdomyosarcoma)
Open Lichtenstein tension free repair
Utilises a patch of non-absorbable mesh to strengthen the
posterior wall of the inguinal canal
Local anaesthesia + sedation or general anaesthesia
Femoral canal
Anterior: inguinal lig
Medial: lacunar lig
Lateral: fem vein
Post: pectineal lig
Contents: lymph node (Cloquet’s node) and fat
Management
All fem hernias should be surgically repaired
Other hernias
Umbilical hernia
Spigelian hernia
True umbilical hernia
Defect between lateral border of the rectus abdominis and
Always congenital
linea semilunaris
Through umbilical cicatrix
Hernial sac comes to lie interstitially between the layers of
May close spontaneously by 3y of age
internal and external oblique and transversus abdominis
Following this, there is little likelihood of improvement and
Difficult to diagnose
surgical repair should be considered
Usually requires imaging—CT
Should be surgically repaired after 3yo
Direct surgical repair indicated
Periumbilical
Always acquired
Not through the umbilicus itself
Common in obese patients and multiparous women
Occasionally strangulate
Assess case by case basis risk vs benefit for surgery
Incisional hernia
Up to 10% of laparotomy incisions eventually herniate
Predisposing factors
Post op wound infection
Abdo obesity
Poor muscle quality (smoking, anaemia)
Multiple operations through the same incision
Poor choice of incision
Inadequate closure technique
Clinical features
Lump and defect: vary from small (more dangerous) to
complete defects
Incisional hernias may be asymptomatic at presentation but
tend to progressively enlarge
May cause strangulation (rare)
Management
Repair indicated for pain or strangulation
Mesh used for larger defects (>4cm)
Obturator hernia
Defect through obturator canal (lateral pelvis into thigh)
Causes medial thigh pain in cutaneous distribution of the
obturator nerve
Very challenging to diagnose – CT required
High risk of obstruction