Median Arcuate Ligament Syndrome: A Case Report

Abstract

Introduction Median arcuate ligament syndrome is a form of nonatherosclerotic visceral ischemia caused by the extrinsic compression of the celiac axis (CA) by the median arcuate ligament. The significance of this finding is controversial, with only 40% of stenoses being symptomatic. This case report describes our findings in a 41-year-old man referred because of an incidental finding of an upper epigastric bruit. Case Report An examination of his mesenteric arteries was requested. A duplex ultrasound of his aorta, CA, and branches, superior mesenteric (SMA) and inferior mesenteric arteries (IMA) was performed. A duplex examination of his aorta revealed no plaque, no significant stenosis, and no aneurysmal dilatation. His SMA and IMA were likewise found to be of normal caliber with no significant stenosis identified. On gentle respiration, the CA was found to have a >70% stenosis with peak systolic velocity (PSV) of 308 cm/sec. On deep expiration, the PSV in CA increased to 385 cm/sec; however, on deep inspiration, the PSV in CA dropped to 121 cm/sec indicating a <70% stenosis. It was noted that there was a change in Doppler angle required to remain parallel to the vessel wall in the CA on deep inspiration from 42 degrees to a deep expiration angle of 58 degrees. Also of note was a hyperechoic band at the base of the CA on B-mode imaging. This was believed to represent either the median arcuate ligament itself or the compression of the CA wall by the ligament. Conclusion Most researchers agree that specific symptomatic patients may benefit from surgical intervention. As this patient was asymptomatic, it was felt that follow-up without intervention was an appropriate course of action at this time.