Acute gastrointestinal manifestation of situs inversus abdominus

Whilst situs inversus is associated with intestinal malrotation and volvulus particularly in infants, this is the first known report of acute intestinal obstruction in an adult patient with a situs anomaly specifically due to a congenital transmesenteric hernia.

A 54-year-old woman presented with a 12-h history of progressive abdominal pain. Contrast-enhanced computed tomography scan of the abdomen revealed an incidental finding of situs inversus abdominus, ischemic small bowel obstruction and a potential occlusive thrombus of the superior mesenteric artery. At operation, the cause of intestinal obstruction was found to be secondary to herniation of the intestine through a congenital mesenteric defect. The hernia was reduced and a strong pulse was subsequently felt in the distal superior mesenteric artery. The patient required resection of a segment of compromised small bowel, and was later anastomosed at a planned second laparotomy. Her laparostomy was closed using an absorbable BioA mesh.

A high index of suspicion and low threshold for exploratory surgery should be maintained in patients with major congenital abdominal anomalies presenting with an acute abdomen.