Three Cases of Median Arcuate Ligament Syndrome in a Tertiary Care Setting

Abstract

Introduction: To increase awareness of median arcuate ligament syndrome as a cause of abdominal pain, weight loss, nausea, and vomiting. Methods: This is a case series of 3 patients. Results: There is no established gold standard to diagnose MALS. It is a diagnosis of exclusion, and therefore a thorough evaluation must be done prior to its selection as the etiology of abdominal pain and weight loss. The flow velocity and the angle of the celiac artery are influenced by diaphragmatic excursion during respiration, and therefore, were used in the proposed diagnostic criteria of MALS. Due to the low prevalence of the disease, the epidemiology remains poorly known and at-risk populations are not defined. Optimal treatment of median arcuate ligament syndrome (MALS) is difficult because the exact cause of the abdominal pain is unknown. One theory is that the median arcuate ligament, a tendinous and muscular tissue, may have a compressive effect on the celiac artery, causing ischemia and pain. Another proposed mechanism of the pain in MALS is related to the celiac plexus, which is in close proximity to the celiac artery. Direct stimulation of the plexus may irritate pain fibers, causing abdominal pain as well as fibrotic changes, or celiac plexus neuromas can mechanically constrict the celiac trunk. It remains unclear to what extent ischemia plays a role in the symptomatology of MALS. Some patients undergo re-vascularization of the celiac artery to treat MALS, which proves a component of ischemia. There are likely multiple contributing factors that cause the symptoms of MALS, and once more is learned about its pathophysiology, treatment can be optimized. Conclusion: MALS is a real entity that is well-described, and needs high clinical suspicion based on history and physical in order to pursue the right diagnostic testing, which includes ultrasound with dopplers or CT scan specifically to evaluate for MALS. Our cases demonstrate 3 patients with varying demographics and presentations who had different treatment approaches with 2 out of 3 patients having complete resolution of symptoms.Figure 1: Peak flow velocity at end inspiration.Figure 2: Peak flow velocity at end expiration.