Incomplete reversed midgut rotation with 540° volvulus in an adult: a case report.

Introduction and importance: Reversed midgut rotation with a retro-arterial transverse colon is a rare cause of adult midgut volvulus, requiring early imaging diagnosis and tailored surgical management. Presentation of case: A 40-year-old man with intermittent abdominal distension presented with acute obstruction. CT showed intestinal malrotation and volvulus with the transverse colon passing behind the superior mesenteric artery (SMA). Ladd's procedure was performed. Recurrent distension on day 5 led to a diverting ileostomy. Three months later, a right hemicolectomy with ileostomy closure was done. Recovery was uneventful. Clinical discussion: Reversed intestinal rotation can trap the transverse colon behind mesenteric vessels, leading to obstruction even after Ladd's procedure. CT findings - such as superior mesenteric artery or vein orientation, duodenojejunal flexure position, cecal location, and the whirl sign - are key for diagnosis and surgical planning. Persistent retro-arterial anatomy may justify elective segmental resection, even in asymptomatic patients. Conclusions: Incomplete reverse midgut volvulus in adults is a rare but potentially life-threatening condition. A high index of clinical suspicion, prompt imaging, and early surgical intervention are essential to optimize patient outcomes.