This site is targeted at medical and radiology professionals, contains user contributed content, and material that may be confusing to a lay audience. Use of this site implies acceptance of our Terms of Use.

Closed loop obstruction

A closed loop obstruction is a specific type of small bowel obstruction in which two points along the course of a bowel are obstructed at a single location thus forming a closed loop. Closed loop usually rotates around its axis, forming a small intestinal volvulus.

Pathology

This is usually secondary to adhesions, a twist of the mesentry or herniation. A similar related pathology is the large bowel volvulus (either sigmoid or caecal). In closed loop obstruction, there is a high risk of strangulation and bowel infarction (10 - 35%).

Radiographic features

CT

Some or all of the following signs may be demonstrated on CT:

  • marked distension of a segment of small bowel
  • radially distributed, C or U-shaped small bowel loops
  • "beak sign" : of the tapering bowel loops at the point of obstruction
  • "whirl sign" : of the tightly twisted mesentery
  • two adjacent collapsed loops of bowel
  • if strangulation is present, signs of bowel ischaemia

Updating… Please wait.
Loadinganimation

 Details successfully updated.

Error Unable to process the form. Check for errors and try again.

 Thank you for updating your details.