Richter's hernia through a missed traumatic abdominal wall defect: A rare cause of early postoperative obstruction after trauma laparotomy

Case report

A man in his 20's presented as an emergency with multiple stab wounds involving the left lateral thorax and abdomen. On examination, he had persistent tachycardia and clinical findings suggestive of peritoneal breach. Focused assessment with sonography for trauma demonstrated free fluid in the peritoneal and left pleural cavities. Emergency exploratory laparotomy was performed, and a left-sided intercostal drain was inserted for the associated pneumothorax.

During laparotomy, a tear in the omentum was identified. Systematic exploration of the abdominal cavity did not reveal any hollow viscus injury nor active bleeding. An omentectomy was performed, and the abdomen was closed after haemostasis and lavage.

In the postoperative period, he continued to have persistent tachycardia with progressive abdominal distension. Plain abdominal radiography demonstrated dilated bowel loops with multiple air–fluid levels suggestive of intestinal obstruction. Computed tomography (CT) scanning, performed approximately 48 h after the initial operation, demonstrated herniation of a segment of ileum through a small defect in the left lateral abdominal wall.

Our patient underwent re-exploration, where a Richter's hernia involving the ileum approximately 150 cm distal to the duodeno-jejunal flexure was identified. A segment of the anti-mesenteric bowel wall had herniated through a small abdominal wall defect measuring approximately 7–8 mm at the site of the stab wound. The bowel was reduced and found to be viable with no evidence of ischaemia or perforation. The fascial defect was repaired and the abdomen closed in layers. The postoperative recovery following the second operation was uneventful, and the patient was discharged on the third postoperative day.

Discussion

Richter's hernia involves entrapment of only the anti-mesenteric wall of the intestine within a small fascial defect. Because luminal continuity may be preserved, early symptoms may be subtle, and the classical features of intestinal obstruction may not initially be present.^1,2 This mechanism also explains why the incarcerated bowel wall is particularly prone to strangulation and necrosis. Traumatic abdominal wall defects created by stab wounds may provide a small opening through which only a portion of the bowel wall becomes incarcerated. Such defects can be easily overlooked during the initial exploration, as occurred in our case. ³

Persistent tachycardia and abdominal distension following trauma laparotomy should therefore prompt evaluation for missed injuries or mechanical obstruction. CT scanning is particularly useful in demonstrating focal bowel wall herniation through a fascial defect and identifying the cause of postoperative obstruction. ⁴ Early recognition and surgical management are essential to prevent bowel strangulation and perforation. With only isolated reports, including a firearm-related case, ⁵ traumatic Richter's hernia should be considered when unexplained postoperative obstruction occurs after trauma laparotomy.