Malrotation Without Midgut Volvulus

  • Etiology: abnormal rotation of the gut as it returns to the abdominal cavity during embryogenesis
  • AXR: usually unremarkable
  • US:reversal of normal relationship of superior mesenteric vein and superior mesenteric artery on axial images – super mesenteric vein is to the right of the superior mesenteric artery in the body, if the superior mesenteric vein is above or to the left of the superior mesenteric artery in the body should raise suspicion for malrotation being present
  • UGI: duodenal-jejunal junction (ligament of Treitz) is where retroperitoneal duodenum comes out into peritoneum and it needs to be over left pedicle of spine or to left of spine and to be at level of duodenal bulb and failure to meet both of these criteria results in diagnosis of malrotation, small intestine in right side of abdomen and colon in left side of abdomen
  • BE: abnormal position of cecum out of right lower quadrant either high in position in the right abdomen or anywhere on the left side of the abdomen should raise suspicion for malrotation being present
  • Treatment: Ladd’s procedure
  • Clinical: commonly seen in heterotaxy syndrome

Radiology Cases of Malrotation Without Midgut Volvulus

Upper GI of malrotation without midgut volvulus in heterotaxy
AP image from an upper GI shows the ligament of Treitz to be in the right upper quadrant. There is no evidence of duodenal obstruction. The proximal jejunum is also in the right upper quadrant. There is also gastroesophageal reflux.
CXR of heterotaxy syndrome and upper GI of malrotation without midgut volvulus
CXR AP (above) shows the cardiac apex to be in the right hemithorax and the gastric bubble to be in the left upper quadrant. AP image from an upper GI (below) shows the ligament of Treitz to be in the right upper quadrant. There is no evidence of duodenal obstruction. The proximal jejunum is also in the right upper quadrant.
Small bowel follow through of malrotation without midgut volvulus
Delayed AP image from an upper GI shows the ligament of Treitz to be over the right pedicle of the L2 verteral body and all of the jejunum to be on the right side of the abdomen.
CT of malrotation without midgut volvulus
Axial CT with contrast of the abdomen shows the unopacified small bowel on the right side of the abdomen and the colon on the left side of the abdomen.