CT Case 048

This is an unusual abdominal x-ray. There is evidence of small bowel obstruction, however the distribution of small bowel, all being located on the patient’s right side, is abnormal.

We know that there is bowel obstruction because we see several distended loops of bowel with multiple air-fluid levels.

We can determine that this is small bowel based on the presence of plicae circulares. These are mucosal folds which are present in the small bowel only and are seen to traverse the entire lumen. This is different from the haustra seen in large bowel, which are thicker and only extend partially across the lumen.

However, the distribution of the small bowel obstruction here is unusual. Anatomically, small bowel is located centrally within the abdomen, however in this case, we see all the loops of small bowel located on the right side of the abdomen.

This distribution of bowel loops raises suspicion for malrotation.

The CT scans confirm intestinal malrotation complicated by bowel obstruction.

Again, we see the distribution of small bowel only on the right side of the abdomen. The bowel loops are again seen to be dilated.

The CT also shows that the duodenal-jejunal flexure is located on right side of the abdomen instead of the left.

There is also inversion of the normal relation of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) with the SMA located to the right of the SMV.

Intestinal malrotation is a congenital condition in which the small intestine fails to develop in the correct location.

It is associated with a Ladd band, a fibrous band, which extends form the caecum to the sub-hepatic region, it causes the caecum to be malpositioned in the right upper quadrant, and as a result causes malrotation of the small intestine.

Clinical consequences of Ladd’s band include increased risk if midgut volvulus and duodenal obstruction from extrinsic compression on the duodenum by the Ladd’s bands.

Intestinal malrotation of the midgut is well documented in infants and children, as patients usually become symptomatic at a young age, but rarely presents for the first time in adulthood.

When this patient went on to have laparotomy for Ladd procedure (adhesiolysis of the Ladd bands) he was found also to have Abdominal Cocoon Syndrome (ACS).

ACS is a rare syndrome in which fibrosis occurs around a section of bowel creating a sac or cocoon, which in itself can lead to intestinal obstruction.

ACS can occur as a result of chronic peritoneal irritation and peritonitis, intraperitoneal chemotherapy or cirrhosis, but mostly it is idiopathic. In this case, it is thought that the cocoon is the result of the Ladd bands fixating the malpositioned bowel in place and causing chronic irritation and inflammation. Surgical management involves incising the cocoon sac and adhesiolysis of the Ladd bands.

• Roy C. Ladd bands. LITFL
• Sharma D, Nair RP, Dani T, Shetty P. Abdominal cocoon-A rare cause of intestinal obstruction. Int J Surg Case Rep. 2013;4(11):955-7.