RESUMO
Superior mesenteric artery syndrome (SMAS) is a rare and potentially life-threatening cause of small bowel obstruction in which the superior mesenteric artery impinges on the third portion of the duodenum. SMAS is typically encountered in patients with low body fat and a history of rapid weight loss and is often diagnosed as a chronic or subacute condition. Here, we describe a case of a healthy adolescent boy without typical SMAS prodromal symptoms presenting with a severe, hyperacute proximal small bowel obstruction due to SMAS. Complications arising from massive gastric and duodenal distension, including gastric, pancreatic and renal ischaemia, necessitated emergent surgical intervention consisting of the duodenojejunostomy bypass with partial gastric resection. The patient recovered without significant lasting consequences.