Collateral circulation as a possible predictor of symptomatic median arcuate ligament syndrome: a case report.

Introduction and importance: Median arcuate ligament syndrome (MALS) is a rare and often underrecognized cause of postprandial abdominal pain resulting from extrinsic compression of the celiac artery by the median arcuate ligament. Diagnosis is challenging due to nonspecific symptoms, overlap with common gastrointestinal conditions, and dynamic anatomical variations. Case presentation: A 48-year-old woman with a 2-year history of postprandial epigastric pain underwent multiple evaluations across specialties without a definitive diagnosis. Contrast-enhanced computed tomography ultimately revealed focal celiac artery stenosis with post-stenotic dilatation and well-developed collateral circulation between the common hepatic artery and superior mesenteric artery, confirming MALS as the cause of her symptoms and guiding a multidisciplinary management plan. Clinical discussion: MALS results from extrinsic compression of the celiac artery, occasionally compounded by variations in arterial origin, ligament position, or neural plexus involvement. Its nonspecific presentation often mimics common gastrointestinal conditions, making imaging essential for diagnosis. Emerging evidence suggests that prominent collateral circulation in the setting of significant celiac artery stenosis is associated with symptom development, as demonstrated in our case. Conclusion: MALS should be considered as a diagnosis of exclusion in patients with persistent postprandial abdominal pain. Recognition of prominent collateral circulation alongside significant celiac artery stenosis may serve as a key indicator of disease severity and symptomatic correlation.