Vomiting as the storyteller in superior mesenteric artery syndrome

BackgroundSuperior mesenteric artery syndrome (SMA) is a rare and underrecognized cause of proximal small intestinal obstruction resulting from compression of the third part of the duodenum between abdominal aorta and superior mesenteric artery. The classic presentation entails postprandial abdominal pain that is relieved in specific postures, early satiety, vomiting and weight loss. However, atypical presentations may lead to delayed diagnosis and management.Case presentationWe report a case of a 28-year-old female who presented with interactable vomiting and progressive weight loss over a two-year period, without associated abdominal pain. Symptoms began during the first trimester of her second pregnancy and persisted despite termination and medical management. She experienced profound hypokalemia, fatigue and oligomenorrhea. Over time, she lost about 30 kg and was complicated with hypothalamic-pituitary axis suppression. Laboratory and ophthalmological work-up ruled out endocrinal, infectious, neurological causes of vomiting. The upper endoscopy revealed pangastritis and duodenitis, while gadolinium-enhanced brain MRI excluded pituitary pathology. Contrast-enhanced CT abdomen demonstrated a narrowed aortomesenteric angle (19.7 degree) and reduced aortomesenteric distance (5 mm), consistent with SMA. The patient failed to respond to conservative measures including nutritional support, electrolyte correction and anti-emetics. She subsequently underwent laparoscopic duodenojejunostomy. Postoperatively, there was marked improvement in her condition regarding resolution of vomiting, weight gain reaching about 60 kg and normalization of hormonal profile.ConclusionThis case underscores the need for heightened clinical suspicion for SMA syndrome in patients with chronic vomiting and weight loss, even in the absence of abdominal pain. Furthermore, hypothalamic-pituitary axis suppression can occur as a rare complication of chronic SMA. Proper clinical, laboratory and radiological assessment should be done for patients diagnosed with SMA to exclude underlying serious illness. Contrast-enhanced CT remains the imaging modality of choice for diagnosis. Early diagnosis is essential for favorable outcomes.