Imaging description

A neonate who was a few days old presented with acute bilious vomiting. A radiograph of the abdomen demonstrated a “double bubble” sign with air in the stomach and the duodenum, but no air in more distal loops of bowel. An upper gastrointestinal (GI) fluoroscopy after oral administration of thin barium solution revealed an obstruction of the proximal duodenum and a “corkscrew” appearance of subsequent small bowel loops (Fig. 50.1). These findings are characteristic for malrotation of the small bowel and midgut volvulus around the mesenteric axis (Fig. 50.2).

Importance

Bowel malrotation occurs when there is abnormal rotation of the bowel in utero, resulting in absence of the normal broad mesenteric fixation from the left upper quadrant (proximal jejunum–ligament of Treitz) to the right lower quadrant (cecal fixation). As a result the mesentery and accompanying vessels have a narrow stalk-like configuration. Midgut volvulus is characterized by rotation of the proximal small bowel around the mesenteric stalk with variable compromise of the blood supply to the bowel. Affected bowel may extend from the proximal duodenum to the mid transverse colon. Arterial compromise may lead to mucosal necrosis, pneumatosis, perforation, peritonitis, and death. Thus, immediate and emergent evaluation is warranted in a case of suspected midgut volvulus.