Hernia Flashcards
List some DDx for abdo pain and mass?
Mechanical - hernia (femoral or direct/indirect inguinal) - obstruction (SBO, LBO) - SBO causes: volvus, intersusseption, CRC, intra-abdo abscess, adhesions, AAA, haematoma - volvulus - stricture - fistula - testicular torsion Inflammatory - IBD: UC, CD - ischaemic bowel disease - diverticulitis - pancreatitis - cholecystitis Infectious - gastroenteritis - C. diff Neoplastic - SB or LB ca -> obstructing - rectal ca Genetic (e.g. Hirschsprung's disease)
Describe examination of the mass?
o Localise (above or below inguinal ligament)
o Cough impulse (?indirect)
o Reducible or not
o Bowel sounds over lumb
o Ring occlusion test- reduce hernia then block deep inguinal ring, then cough/strain to see if bulges out again
- Bulges out again -> direct hernia (only external/superficial inguinal ring)
o Blue dot sign- testicular torsion
Describe abdo x-ray findings consistent with a bowel obstruction?
- SB dilated >30mm
- Multiple air/fluid levels in SB
- “Stretch/slit sign”- slit of air caught in valvulae conniventes (SB mucosal folds)
- “String of pearls sign”- small air bubbles trapped in the valvulae conniventes of SB
- “Step ladder sign”- gas-fluid distended small bowel loops that appear to be stacked on top of each other
- Coiled spring sign- intussusception
Differentiate between SBO and LBO?
SBO:
- Causes: adhesions, hernia, volvulus, malignancy
- Clinical: pain (SBO colicky), vomiting, distension, constipation
- Abdo x-ray: “step ladder sign” and “string of pearls sign”
LBO:
- Causes: stricture (from diverticular disease), sigmoid volvulus, malignancy
- Clinical: pain, distention, vomiting, constipation
- Abdo x-ray: dilated colon and caecum
Describe the boundaries of the inguinal canal?
Inguinal canal: 4cm long from superficial ring to deep ring
• Superficial ring- opening in anterior wall between the medial and lateral crux of the external oblique aponeurosis (attaching to the pubic symphysis and PT respectively)
• Deep ring- comes from opening of transversalis fascia
Describe the contents of the inguinal canal?
MALT mnemonic:
M- Muscles (2 superior): transversalis abdominis muscle and internal oblique muscle
A- Aponeuroses (2 anterior): external oblique and internal oblique aponeurosis
L- Ligaments (2 inferior): inguinal ligament and lacunar ligament
T- (posterior 2 Ts): transversalis fascia and conjoint tendon
Differentiate between a direct and indirect hernia?
Direct hernia:
- Anatomy: only enters the external/superficial inguinal ring -> through Hesselbach’s triangle
- Epi: older men (weak abdo wall)
Indirect hernia:
- Anatomy: enters the internal/deep inguinal ring, the external ring and descends into the scrotum (following the path of testicular descent) -> through inguinal canal
- Epi: infants
What are the borders of Hesselbach’s triangle?
- Medial: lateral margin of rectus abdominis sheath (lineal semilunaris)
- Inferior: inferior epigastric vessles
- Superior: femoral vein
Describe the relevant anatomy for a femoral hernia?
A femoral hernia is one occurring below the inguinal ligament -> through the femoral canal -> through the femoral triangle
- Inguinal anatomy (NAVEL mnemonic, lateral to medial) N- nerve (femoral) A- artery V- vein E- empty space -> femoral canal L- inguinal ligament
- Femoral triangle (triangle of Scarpa):
o Superior: inguinal ligament
o Lateral: sartorius muscle
o Medial: adductor longus muscle
- Femoral canal o Medial: lacunar ligaement o Lateral: femoral vein o Anterior: inguinal ligament o Posterior: pectineus muscle, pectineal ligament, superior ramus of pubic bone
List types of hernia?
- Inguinal- occurring below inguinal lig, most common
- Incisional
- Femoral
- Umbilical
- Epigastric
- Hiatal (stomach fundus bulges into chest through oesophageal opening in diaphragm)
- Internal into duodenal of caecal recesses
Describe the descent of the testis and the pathway for weakness?
Testicular descent:
o Testes originate near kidneys
o Descend moving forwards, downwards and outwards
o Peritoneal outpouching (processus vaginalis) -> pushes through all layers of abdominal wall -> makes space for testes to descend (next to this space, not through it)
o Gubernaculum extends from base of scrotum to gonads -> contracts to facilitated descent
o Testes and assoc neurovasculature and ducts (spermatic cord) pass through inguinal canal
o Processus vaginalis obliterates
Weakness:
o If processus vaginalis does not close -> weakness in anterior abdo wall -> inguinal hernia
How would you manage a hernia?
Priority: prevent strangulation • Conservative: o NBM o IV fluids and electrolytes o NG drainage o Prophylactic abx (if concern for peritonitis) • Surgical o Open mesh repair o Bowel resection of necrotic bowel
List DDx for a groin lump?
Above inguinal ligament:
o Direct inguinal hernia (only enters external inguinal ring)
o Indirect inguinal hernia (enters internal inguinal ring, external inguinal ring and scrotum)
o Undescended testes
o Hydrocele or lipoma of spermatic cord
o Iliac node lymphadenopathy
Below inguinal ligament: o Femoral hernia o Psoas abscess o Femoral aneurysm o Saphenous varix (dilation of saphenous vein as it joins the femoral vein) o Lymphadenopathy
What are the risk factors of hernia?
Modifiable: o Obesity (stretching abdominal musculature) o Weight lifting o Previous abdominal surgery o Smoking (collagen deficiency) o COPD/emphysema -> chronic cough o Strained defecation
Non-modifiable: o Increased age o Male gender o FMHx o Prematurity (increased risk of processus vaginalis closure) o Strained micturition o Chronic cough o Pregnancy (stretching abdominal musculature) o Peritoneal dialysis
