Exercise-induced Abdominal Pain: Median Arcuate Ligament Syndrome

Abstract

Introduction: The median arcuate ligament joins the right and left crura of the diaphragm while allowing passage of the aorta into the abdomen. Median arcuate ligament syndrome (MALS) or celiac axis compression syndrome (CACS) is a result of a low lying median arcuate ligament compressing the proximal celiac trunk (branch of aorta supplying primarily the stomach) causing intermittent ischemic symptoms of abdominal pain, weight loss and exercise intolerance. Case Report: A 70-year-old Caucasian with presented with a one year history of intermittent aching abdominal pain located in the epigastric and left hypochondriac region. The pain is constant with frequent exacerbations provoked by eating (variable) and exercising (consistent), relieved by cessation of eating and by physical rest respectively. Exacerbations led to alternating changes in bowel movements from constipation to diarrhea along with weight loss of ten pounds over the last two months. The patient denied any nausea, vomiting, fevers or bloody bowel movements. Multiple colonoscopies and endoscopies have been negative. Physical exam was unremarkable except for mild tenderness in the epigastric region. Computerized Tomography (CT) abdomen with contrast showed poor contrast flow through the celiac artery with a “hooked” appearance. The diagnosis of MALS was made and the patient was referred to surgery for medial arcuate ligament division. Discussion: Patient with chronic abdominal pain associated with weight loss and exacerbations with exercise should have MALS in the differential. Eating stimulates increased metabolic demand for the stomach leading to mismatched perfusion via a compromised celiac artery. During exercise, the diaphragm expands at a higher frequency and force to accommodate for increased oxygen demand. This leads to further reduction of celiac artery flow in patient with MALS. CT Sagital images demonstrating acute angulation and narrowing of the proximal celiac artery causing a “hooked” appearance (arrow) is characteristic of median arcuate ligament syndrome.Figure: Arrow indicates “hooked” appearance of celiac artery due to compression by medial arcuate ligament from above.