A Ligamentous Agony: Median Arcuate Ligament Syndrome as an Under-Recognized Cause of Abdominal Pain.

Abstract

Median arcuate ligament (MAL) syndrome (MALS) is a rare clinical entity characterized by chronic abdominal pain resulting from compression of the celiac artery by the MAL. We present a case of MALS with imaging evidence of anterior compression of the celiac artery on expiration, which was relieved on inspiration. A 33-year-old woman presented with intermittent upper abdominal pain since three months. The pain was associated with nausea, abdominal bloating and diarrhea. Physical examination revealed a palpable abdominal aorta with no bruit. Abdominal sonogram, upper and lower gastrointestinal endoscopies, celiac disease screening, clostridium difficile toxin assays and hepatobiliary iminodiacetic acid scan were all normal. Computerized tomography angiogram (CTA) revealed subtle narrowing at the origin of the celiac artery without any atherosclerosis or calcification. Lateral aortic angiography showed anterior impression on the celiac artery at its origin on expiration. The constriction was relieved on inspiratory film - findings most consistent with MALS. MALS is rare, typically presenting with non-specific symptoms including nausea, vomiting, chronic post-prandial abdominal pain or unintentional weight loss. Angiography with respiratory maneuvers remains the diagnostic standard. However, non-invasive vascular imaging during both phases of respiration can be considered as an initial diagnostic test. The primary goal of therapy is celiac artery decompression with the additional objective of neuronolysis of the celiac ganglion. Our case highlights that MALS should be considered as a differential diagnosis in chronic, recurrent abdominal pain, particularly with an unrevealing initial evaluation. Evidence of celiac artery compression on vascular imaging, with characteristic respiratory variation, is highly suggestive of MALS.