Colonic Closed Loop Obstruction

Supine radiographic study of a 41-year-old woman shows a focally dilated loop of large bowel (star) in the right side of the abdomen. There is little gas in the more distal colon.

Axial CT image shows a dilated right colon (star) with a transition point with a 'whirl-like' appearance (shown on contiguous images) in the mid abdomen (arrow). The rest of the colon is not dilated. Findings are most concerning for closed loop obstruction.

Facts: Closed Loop Obstruction of the Colon

• Colonic obstruction is rarely caused by postoperative adhesion (less than 1%). It is most commonly due to tumor
• CT should be the next imaging work-up to look for a mass. Contrast enema should be omitted due to the risk of perforation
• Closed loop obstruction of the colon usually is due to volvulus, which can be sigmoid (80%), cecal (15%) or involving the transverse colon (5%). Long mesocolon can predispose to malrotated cecum and result in a bascule or volvulus
• Signs of closed loop obstruction on imaging include focally dilated bowel loop with little gas distally and proximally, transition point with a whirl-like appearance at the mesenteric root, mesenteric haziness and free fluid

Our case: transverse colonic closed loop obstruction due to extralong colonic mesentery

Reference:

Halpert RD. Gastrointestinal imaging case review series, 2nd ed, 2008.