Superior mesenteric vein syndrome: A rare cause of duodenal obstruction mimicking SMA syndrome – Case report and surgical management

Background: Superior Mesenteric Vein (SMV) syndrome is an extremely rare cause of duodenal obstruction, resulting from external compression of the third portion of the duodenum by the SMV against the aorta. Due to its rarity and clinical similarity to Superior Mesenteric Artery (SMA) Syndrome, SMV syndrome may be misdiagnosed. Case presentation: We present a 41-year-old male with progressive postprandial epigastric pain, nausea, vomiting, and 20 kg weight loss over six months. Imaging revealed compression of the duodenum by the SMV, with a normal aortomesenteric angle and distance, confirming the diagnosis of SMV Syndrome. Despite initial conservative management, including dietary modifications, positional changes, and nutritional support, symptoms persisted. The patient underwent laparoscopic duodenojejunostomy, leading to significant symptom relief and weight gain. Conclusion: This case, the third reported in the literature, emphasizes the importance of contrast-enhanced CT with venous phase imaging for accurate diagnosis. Given the similarities with SMA Syndrome, a stepwise treatment approach is recommended, with surgery reserved for refractory cases. Increased awareness and further research are needed to optimize the management of this rare condition.