Intestinal malrotation combined with superior mesenteric artery syndrome: a case report.

Background: Intestinal malrotation (IM) is a developmental anomaly of the intestine characterized by abnormal rotation of the midgut around the superior mesenteric artery (SMA) axis. This condition is more prevalent in children under 1 year of age. Superior mesenteric artery syndrome (SMAS) is a rare disorder caused by a decreased angle between the abdominal aorta (AA) and the SMA, leading to compression of the horizontal segment of the duodenum. Both conditions present with symptoms such as abdominal pain and vomiting. A preoperative diagnosis that relies exclusively on clinical manifestations and imaging examinations may lead to misdiagnosis or overlooking of the condition. Case description: A 13-year-old female patient was admitted to the hospital with a 12-h history of abdominal pain accompanied by vomiting and reduced passage of flatus. Physical examination revealed tenderness in the upper abdomen and periumbilical region, along with diminished bowel sounds. Preoperative imaging revealed a "vortex sign" and a reduced angle between AA and SMA (10°). During surgery, a 270° reverse rotation of the intestine was observed. The angle between the AA and SMA was further reduced, and SMA was positioned in close proximity to the duodenum. Obstruction of the distal descending duodenum was also observed. The patient was diagnosed with reverse intestinal malrotation (RIM) combined with SMAS. The patient underwent Ladd's procedure and duodenojejunostomy and recovered completely after the operation. No abnormalities were observed during the follow-up. Conclusions: In patients presenting with IM accompanied by abdominal pain and vomiting, clinicians should consider the possibility of RIM and SMAS. A comprehensive preoperative evaluation is essential to exclude complex gastrointestinal malformations, thereby optimizing the surgical strategy and enhancing postoperative recovery.