Malrotation/Volvulus

• Malrotation involves arrest of nl counterclockwise rotation of gut around the SMA, leaving intestines in abnormal position with inadequate retroperitoneal attachment

• Volvulus occurs when intestine twists, cutting off blood supply

• Presents with bilious emesis, abdomenal distention, bloody stools

• Dx: UGI reveals duodenal “C” loop failing to cross to the left of the midline, and proximal jejunal loops to the right

• Rx: Reduction of volvulus, resection of Ladd's bands, replacement of colon in RLQ

There are three types of midgut malrotation*.

• Type I malrotation occurs before 6 weeks of gestational age. The duodenum and the large bowel stop rotating after their first 90 degrees counter-clockwise rotation. These are not clinically significant because good fixation prevents volvulus.

• Type II malrotation occurs between six and ten weeks of gestational age. It primarily affects the duodenum because this is the only portion of the bowel rotating at this time.

• Type III malrotation occurs after ten weeks of gestational age. The duodenum has only 90 degrees of rotation left to complete and the large bowel 180 degrees.

  • Type III A, there is either a complete obstruction from Ladd's bands or volvulus. This is the most dangerous type of malrotation. Volvulus, gangrene and death are common.

  •  Type III B is incomplete fixation of the hepatic flexure.

  •  Type III C is incomplete fixation of the cecum and mesocecum.

  •  Type III D is an internal hernia at the ligament of Treitz.

*Nair S, Lal R (2003, Nov 10).
Transverse colon volvulus due to ladd's band, {Online}.
URL: http://www.eurorad.org/case.php?id=2556