Acute superior mesenteric artery syndrome in a young adult: case report

Superior mesenteric artery (SMA) syndrome is a rare condition (incidence of 0.013%-0.78%) that primarily affects young adults, resulting from duodenal compression between the SMA and the aorta following rapid weight loss and retroperitoneal fat pad depletion. Conservative management succeeds in 70-80% of cases; surgical intervention is required for refractory symptoms.

A 21-year-old woman presented with severe abdominal pain, nausea, and bilious vomiting following a 36% weight reduction over 5 months (66-42 kg; body mass index [BMI] 17.48 kg/m²). CT revealed gastroduodenal dilatation with an aortomesenteric angle of 18° (normal 28-65°) and a distance of 4.5 mm (normal 10-34 mm), confirming SMA syndrome. After 4 days of unsuccessful conservative management, laparoscopic surgery was initiated with Strong's procedure. Periduodenal fibrosis caused persistent obstruction, requiring immediate conversion to extracorporeal duodenojejunostomy. Recovery was uncomplicated, with oral intake by postoperative day 6. At the 2-month follow-up, she achieved complete symptom resolution with an 8 kg weight gain (BMI 20.81 kg/m²).

When Strong's procedure fails due to periduodenal fibrosis, immediate intraoperative conversion to duodenojejunostomy is safe and effective, sparing a malnourished patient a second procedure. Review of 20 surgically managed cases (2011-2025) confirms that most proceed directly to duodenojejunostomy; this fibrosis-driven conversion strategy is infrequently described and offers a practical framework for intraoperative decision-making in high-risk patients.

Early surgical consultation is recommended when conservative treatment fails. In malnourished patients with suspected periduodenal fibrosis, preoperative planning should anticipate possible intraoperative conversion; immediate bypass during the same operation avoids a second procedure and its associated morbidity.