Malrotation With Midgut Volvulus

  • Etiology: prerequisite is malrotation – abnormal rotation of the gut as it returns to the abdominal cavity during embryogenesis -> narrow mesenteric root -> twisting of mesenteric pedicle around superior mesenteric artery -> bowel obstruction and bowel ischemia / necrosis
  • 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, whirlpool sign – swirling of mesenteric vasculature around itself – is sign of midgut volvulus
  • 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 with small intestine in right side of abdomen and colon in left side of abdomen, often a spiral / corkscrew appearance to the duodenum / proximal jejunum which is a demonstration of the volvulized bowel
  • 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, swirling of the terminal ileum is a sign of midgut volvulus
  • Treatment: Ladd’s procedure
  • Clinical: most occur early in life with 40% in first 10 days and 90% in first 3 months of life, bilious vomiting is radiological and surgical emergency as strangulation sequence can happen in few hours: malrotation -> narrow mesenteric root -> volvulus -> venous obstruction -> continued arterial inflow -> venous congestion -> raised tissue pressure above blood pressure -> cessation of arterial flow / arterial obstruction -> midgut necrosis from jejunum to middle of colon, in older children and adults may present as episodes of spontaneously resolving duodenal obstruction

Radiology Cases of Malrotation With Midgut Volvulus

AXR of small bowel obstruction due to malrotation with midgut volvulus
AXR supine shows multiple dilated loops of bowel with thickened walls.
UGI of malrotation with midgut volvulus
Two AP images from an upper GI exam show the duodenal-jejunal junction to be to the left of the spine but to be low lying. The proximal jejunum has a spiral appearance.
Upper GI of malrotation with midgut volvulus
AP image from an upper GI (left) shows the ligament of Treitz projecting over the right pedicle of the L2 vertebral body and to be lower in position than the duodenal bulb that projects over the right pedicle of the L1 vertebral body. The spiral appearance of the proximal jejunum is best appreciated on the lateral image (right).
Upper GI of malrotation with midgut volvulus
AP image from an upper GI shows complete obstruction of the duodenum at the junction of the second and third parts of the duodenum and associated massive gastroesophageal reflux. A final image taken 5 minutes later was unchanged.

Radiology Cases of Malrotation With Chronic Midgut Volvulus

Upper GI of malrotation with chronic midgut volvulus
AP image from a small bowel follow through exam (below) shows the small bowel on the right side of the abdomen and the colon on the left side of the abdomen. Close examination of the upper GI portion of the exam (above) beyond the abnormal position of the ligament of Treitz shows a thickened appearance of the folds throughout the duodenum (above left) and proximal jejunum (above right) but there was no evidence of spiraling of the bowel or obstruction.

Surgery Cases of Malrotation With Midgut Volvulus

Surgical image
Surgical image shows the entire small bowel, from the jejunum to the terminal ileum, to be infarcted.