Take home points : · Schematic drawings of normal rotation and malrotation :
- A, Drawing
shows that normal 270° rotation and fixation of midgut results in familiar positioning of bowel with broad mesenteric attachment (dotted line).
- B, Drawing shows that malrotation results in malpositioned bowel and narrow base of mesenteric fixation (dotted line), which is prone to midgut volvulus. Abnormal fibrous peritoneal bands of Ladd (curved lines) that attach to right colon predispose to internal hernia in older patients.
· Congenital malrotation of the midgut often presents within the first month of life, but some patients will present years later or remain asymptomatic for life.
· Midgut volvulus is a complication of malrotation in which clockwise twisting of the bowel around the SMA axis occurs because of the narrowed mesenteric attachment . This life-threatening condition is a clear indication for emergent surgery.
· The clinical diagnosis of midgut volvulus in adolescents and adults is difficult
because the presentation is usually nonspecific and malrotation is rarely considered.
· Recurrent episodes of colicky abdominal pain with vomiting over a period of months or years are typical and may eventually lead to imaging
· The CT findings of malrotation with midgut volvulus are characteristic. The CT whirl or whirlpool sign describes the swirling appearance of bowel and mesentery twisted around the SMA axis .
· Additional CT findings include duodenal obstruction, congestion of the mesenteric vasculature, and evidence of underlying malrotation with the duodenal–jejunal junction fails to cross the midline and lies below the levelof the duodenal
bulb.
· The presence of intestinal ischemia or necrosis is an ominous sign