Median Arcuate Ligament Syndrome as a Cause of Chronic Abdominal Pain in an Adolescent: A Case Report

Abstract

Background: Median arcuate ligament syndrome (MALS) is a rare cause of chronic abdominal pain resulting from compression of the celiac artery by the median arcuate ligament. Diagnosis in children is often delayed because of non-specific symptoms and a low index of suspicion, owing to the relatively low reported prevalence of 1.7% in the paediatric population. Case Presentation: A 15-year-old boy presented with severe post-prandial peri-umbilical pain for 7 months, associated with constipation and a 5 kg weight loss. Previous investigations and symptomatic treatment at multiple centres were unrevealing. Laboratory tests, abdominal ultrasonography, and gastrointestinal endoscopy were normal. Contrast-enhanced computed tomography demonstrated focal narrowing of the celiac artery with post-stenotic dilatation. Mesenteric Doppler showed aliasing at the origin of the celiac artery, with an elevated peak systolic velocity (PSV) of 234 cm/s during expiration. Three-dimensional reconstruction revealed a characteristic “J-hook” appearance of the celiac artery. A diagnostic celiac plexus block produced complete but temporary pain relief. The patient subsequently underwent open surgical release of the median arcuate ligament, with complete resolution of symptoms. Follow-up Doppler demonstrated a reduction in PSV to 154 cm/s, and he remained asymptomatic at 2.5 years. Conclusion: MALS should be considered in adolescents with unexplained chronic post-prandial abdominal pain. Early diagnosis and multidisciplinary management can achieve favourable outcomes.