Median Arcuate Ligament Syndrome: A Nonvascular, Vascular Diagnosis

Abstract

Median arcuate ligament syndrome (MALS) is often diagnosed when idiopathic, episodic abdominal pain is associated with dynamic compression of the proximal celiac artery by fibers of the median arcuate ligament. The character of the abdominal pain is often postprandial and associated with gradual weight loss from poor food intake, suggestive of chronic mesenteric ischemia. However, the pathognomonic imaging feature of dynamic, ostial celiac artery compression with expiration does not consistently predict clinical improvement from revascularization. Proposed but unproven pathophysiological mechanisms include neurogenic pain from compression of the splanchnic nerve plexus and intermittent ischemia from compression of the celiac artery. Alterations in blood flow and ganglion compression are both associated with delayed gastric emptying, another physiological correlate of the clinical syndrome. Published reports describe a variable response to revascularization and nerve plexus resection suggest a need for translational research to better characterize this poorly understood clinical entity. We illustrate the current gaps in our knowledge of MALS with the case of a 51-year-old woman with a 4-year history of chronic abdominal pain who responded to a combination of ganglion resection and celiac artery reconstruction.