Incidental diagnosis of true intestinal malrotation

Intestinal malrotation (IM) (or nonrotation) is an embryologic anomaly occurring in gestational week 11 and presenting with obstruction in the frst month of life. Asymptomatic IM is estimated to occur in 1 out of 500 live births [1]. However, the true incidence of IM in adults is unknown and IM may be an incidental fnding during abdominal surgery [2, 3]. In fact, few case reports of IM have been published so far [4]. Wang and Welch classifed IM into four types: non-rotation with incomplete 90° rotation, malrotation with 180° rotation, reversed rotation, and paraduodenal hernia [5]. Intestinal motility was assessed by the colonic transit studies, resulting in normal transit time. A 36-year-old woman was referred by gynaecologists to our outpatient clinic with a diagnosis of subacute adhesive large bowel obstruction. She complained of multiple episodes of chronic diarrhea associated with severe abdominal pain and recurrent constipation. During a prior laparoscopy for an ectopic pregnancy, IM had been an incidental fnding, with a left-sided ileocecal valve adherent to the ascending colon, and with congenital colo-colic adhesions at the level of the descending colon. Subsequently, a barium enema confrmed the diagnosis of IM: the entire colon was located on the left side as a result of embryonic non-rotation of the intestine (Fig. 1a, b), while the small bowel was on the opposite side of the abdomen. A computed tomography scan was performed and carefully reviewed showing the right-sided small bowel, the left-sided colon sign and the inverse position of the superior mesenteric vein (Fig. 2). The IM was therefore classifed as belonging to the WangWelch’s group I, non-rotation with incomplete 90° rotation [5]. Finally, a diagnostic laparoscopy with adhesiolysis between the ascending and descending colon was satisfactorily performed. The postoperative course was uneventful and at 6 months there was no recurrence of the preoperative symptoms.