2694 Median Arcuate Ligament Syndrome: The Ambiguous Cause of Abdominal Pain

Abstract

INTRODUCTION: Median Arcuate Ligament Syndrome (MALS) is often under-diagnosed due to its rarity and overlap of symptomatology with other abdominal pathologies. The pathology involves the median arcuate ligament compressing the celiac artery leading to chronic, postprandial abdominal pain, nausea, vomiting, and weight loss. Making the diagnosis is complicated by a lack of sensitive diagnostic modalities. CASE DESCRIPTION/METHODS: A 69-year-old female with a history of emphysema, scoliosis, and interstitial cystitis presented for severe postprandial abdominal pain, nausea, vomiting, and anorexia from fear of food. She had a standing diagnosis of chronic ischemic mesenteric colitis for years. On examination, she had diffuse abdominal tenderness with radiation down to her upper thighs, nausea, vomiting, and cachexia. The initial labs were unrevealing. CT abdomen demonstrated severe arteriosclerosis of the celiac artery with 75% stenosis, as well as moderate stenosis of SMA, IMA, and bilateral renal arteries. Despite an inconsistent physical exam, vascular surgery agreed with the reading of ischemic colitis and suggested that a celiac stent be placed. Upon further review of the CT and an interdisciplinary conference, her images were determined to be consistent with celiac artery compression. The patient is to be scheduled for the release of the median arcuate ligament with a possible celiac nerve block. DISCUSSION: When suspecting MALS, a triad of postprandial abdominal pain, weight loss, and abdominal bruit may be the only findings to suggest the diagnosis. With our patient not having a bruit and imaging showing severe stenosis, this only made the diagnosis of MALS even more discrete. Imaging may show a narrowing of the celiac artery for further clues followed by confirmation testing via: • Inspiratory/Expiratory ultrasonography – may show an increased visible compression of the artery during expiration with the increased blood flow velocity. • Gastric Tonometry – physiological testing, as well as measurements of arterial PaCO2 levels before and after exercise, may also be used to predict the success of decompression. • Ganglion Nerve Block – percutaneous celiac ganglion block, using an anesthetic to block nerve fibers of celiac plexus, which may be diagnostic and therapeutic. This case presents the difficulty of diagnosing MALS due to its overlap with the more common ischemic colitis. Having a keen clinical suspicion with a better understanding of the workup for MALS may prevent misdiagnoses and misguided therapies.