Superior Mesenteric Artery Syndrome Presenting With Refractory Vomiting and Acute Kidney Injury: A Case Report.

Superior mesenteric artery syndrome (SMAS) is a rare cause of upper gastrointestinal obstruction caused by compression of the third portion of the duodenum between the abdominal aorta and the superior mesenteric artery, usually due to rapid weight loss or an anatomical predisposition that reduces the retroperitoneal fat pad between these vessels. Its symptoms often mimic more common gastrointestinal disorders, which can delay diagnosis, making cross-sectional imaging, particularly computed tomography (CT), essential for identifying a reduced aortomesenteric angle and distance with proximal duodenal dilatation. We report the case of a 17-year-old female patient who presented with persistent nausea, vomiting, and inability to tolerate oral intake despite extensive gastroenterological evaluation; upper gastrointestinal endoscopy and magnetic resonance cholangiopancreatography were unremarkable, but CT subsequently demonstrated an aortomesenteric angle of approximately 17° and a distance of approximately 7 mm with proximal duodenal dilatation, consistent with SMAS. She was managed conservatively with nutritional optimisation and supportive therapy. This case highlights the diagnostic challenge of SMAS and underscores the importance of considering it in patients with unexplained persistent vomiting, as early recognition and appropriate imaging are crucial to prevent prolonged morbidity and unnecessary investigations.