Superior mesenteric artery syndrome complicating severe acute malnutrition secondary to pulmonary tuberculosis in an adolescent: a case report

Background Superior mesenteric artery (SMA) syndrome is a rare cause of upper gastrointestinal obstruction defined by extrinsic compression of the third portion of the duodenum between the SMA and the abdominal aorta, resulting from depletion of the retroperitoneal fat pad. It predominantly affects adolescents, is rarer in children, and carries a reported mortality of up to 33% when diagnosis is delayed. Case summary A 16-year-old male presented with a three-month history of progressive weight loss, anorexia, productive cough, night sweats, abdominal pain, and bilious vomiting. He had a household contact with confirmed pulmonary tuberculosis (TB). Admission anthropometry revealed a body mass index (BMI) of 12 kg/m² and mid-upper arm circumference (MUAC) of 13 cm, confirming severe acute malnutrition (SAM). Sputum GeneXpert was positive for Mycobacterium tuberculosis. CT scan confirmed SMA syndrome with an aortomesenteric angle of 22° and distance of 6 mm. The patient was managed conservatively with ReSoMal rehydration via nasogastric tube (NGT), electrolyte correction, enteral feeding initiated with F-75 formula and advanced to F-100 following stabilization, intravenous antibiotics, and four-drug anti-tuberculosis therapy (isoniazid, rifampicin, ethambutol, pyrazinamide) initiated after two weeks of nutritional stabilization. Refeeding syndrome was anticipated and monitored throughout nutritional rehabilitation. Planned surgery was deferred after clinical improvement. Bilious vomiting and abdominal pain resolved over four months; by seven months, the patient had achieved significant weight gain and was tolerating a full family diet. Conclusion This case illustrates the bidirectional and compounding relationship between SAM driven by pulmonary TB and SMA syndrome. Conservative nutritional rehabilitation was curative, obviating surgery. Clinicians in TB-endemic, resource-limited settings should maintain a high index of suspicion for SMA syndrome when standard malnutrition management fails. Trial registration Not applicable. This study was not a clinical trial.