Abdominal Wall and Hernia Surgery
The abdominal wall domain tests groin anatomy, the grammar of hernia classification, the choice between tissue repair and mesh, and the management of the emergency hernia. Cuban examinations frequently pair an anatomical landmark with a surgical decision, so be able to draw Hesselbach's triangle from memory.
Anatomy you must be able to draw
- Hesselbach's triangle: inferior epigastric vessels laterally, rectus sheath medially, inguinal ligament inferiorly - the site of direct hernias.
- The myopectineal orifice of Fruchaud is the common site of all groin hernias; laparoscopic mesh must cover it entirely.
- Indirect hernias lie lateral to the inferior epigastric vessels and pass through the deep ring; femoral hernias pass under the inguinal ligament, medial to the femoral vein.
- The ilioinguinal, iliohypogastric and genitofemoral nerves are at risk; the ilioinguinal nerve is the commonest source of post-herniorrhaphy neuralgia.
Classification and technique
- EHS classification: site (L lateral, M medial, F femoral), size, and primary or recurrent.
- Lichtenstein tension-free mesh is the standard open repair for a unilateral primary inguinal hernia; Shouldice is the best pure tissue repair.
- TAPP or TEP for bilateral and recurrent hernias; TEP avoids entering the peritoneal cavity.
- Femoral hernia carries a high strangulation risk and is repaired early, by a low (Lockwood) or inguinal approach with mesh plug or McVay repair.
- Ventral hernia: component separation for large defects; avoid mesh in an infected field, and remove infected mesh.
Worked example
A 72-year-old woman has a painful 2 cm lump below the inguinal ligament, medial to the femoral vein, with vomiting. Reasoning: this is an incarcerated femoral hernia, and femoral hernias strangulate early, so it is an emergency. Resuscitate, give antibiotics, and operate; assess bowel viability and resect if necrotic; repair through a low approach, using mesh only if the field is clean, otherwise a tissue repair.
Traps
- Calling every groin lump an inguinal hernia - palpate the pubic tubercle; the swelling lies below it in femoral hernia.
- Placing mesh in a contaminated strangulated field.
- Expecting durability from simple suture repair in a patient with chronic cough or connective tissue disease.
- Missing Richter's hernia, where only part of the bowel wall strangulates, so obstruction may be absent.