Richter Hernia

A Richter hernia occurs when only part of the circumference of the bowel wall, usually the antimesenteric border, becomes trapped within a small fascial defect.

Because the intestinal lumen is not completely occluded, the patient may continue passing stool and flatus despite progressive strangulation of the trapped bowel wall.

This makes Richter hernia particularly dangerous. Bowel necrosis or perforation can occur without classical complete bowel obstruction.

Common sites include femoral and inguinal defects and small laparoscopic port sites.

Presentation may be deceptively mild.

There is often focal pain and tenderness over a small irreducible hernia, while vomiting and abdominal distension may be absent.

Patients can continue passing stool.

As strangulation progresses, local erythema, increasing pain, fever, tachycardia and systemic toxicity develop.

If the trapped segment necroses and perforates, the patient may present with local abscess, enterocutaneous fistula or generalised peritonitis rather than obstruction.

Diagnosis requires high clinical suspicion.

CT abdomen and pelvis with IV contrast: may demonstrate focal entrapment of the bowel wall within a small defect and assess viability, but imaging can occasionally miss partial wall incarceration.

Persistent focal hernia pain despite continuing bowel function should not be dismissed because obstruction is absent.

A reducible Richter hernia without acute symptoms should undergo planned repair because future strangulation risk remains.

An acutely tender irreducible Richter hernia requires urgent operative assessment.

Do not use continued passage of stool or absence of bowel dilatation as evidence that urgent surgery is unnecessary.

At operation, release the trapped bowel and assess the entire circumference carefully. A small antimesenteric segment can appear severely compromised while the remaining bowel appears normal.

If viability returns completely after reduction, bowel resection is unnecessary.

Full thickness necrosis requires excision. Segmental small bowel resection with primary anastomosis is preferred when the necrotic area is substantial, margins are uncertain or limited repair would compromise lumen calibre.

Repair the underlying femoral, inguinal, port site or ventral defect.

Synthetic mesh is appropriate if the field remains clean. Gross perforation or heavy enteric contamination should generally preclude permanent synthetic prosthetic placement during the contaminated phase.

If the hernia contents reduce spontaneously during anaesthetic induction before bowel viability has been seen, inspect the bowel laparoscopically or through an appropriate abdominal approach rather than assuming that the reduced segment is viable.