Intramesosigmoid hernia complicated by strangulated small-bowel obstruction

Abstract

An intramesosigmoid hernia is 1 of the 3 rare types of sigmoid-related hernias that could be complicated by intestinal obstruction. Our patient presented with a clinical picture of intestinal obstruction. CT scan showed features of strangulated small-bowel obstruction secondary to a sigmoid-related hernia. This was confirmed intraoperatively to be an intramesosigmoid hernia. We share the radiological findings with intraoperative surgical correlation and discuss the imaging features described in the literature.

Figure 1

The supine abdominal radiograph of the patient showing several dilated small intestinal loops, suspicious for small-bowel obstruction with a distal transition zone. There is no evidence of overt pneumoperitoneum.

Figure 2

The unenhanced coronal CT image showing a C-shaped appearance of the dilated small bowel (white arrow) with mesenteric engorgement and fat stranding suggestive of strangulation.

Figure 3

The oblique reformatted CT image better demonstrating the herniated loop of small bowel (white arrow) with a transition zone.

Figure 4

The axial CT image showing the dilated small bowel (*) in an abnormal position, posterolateral to the sigmoid colon that contains intraluminal contrast (white arrow). Its transition zone points medially (black arrow) with a beak-like appearance.

Figure 5

A diagrammatic illustration showing the anatomical relationship of the bowel loops in an intramesosigmoid hernia. The bowel herniates through a defect in the medial leaf of the mesocolon (white arrow) into a sac formed by the lateral leaf of the mesocolon (black arrow). The herniated bowel is found anterior to the left psoas muscle (*) and posterior to the sigmoid.

Figure 6

An intraoperative photograph showing the defect in the medial leaf of the mesocolon (white arrow), through which the discoloured ischaemic small bowel had herniated through.