Intraoperative evaluation of median arcuate ligament syndrome using a transit-time flowmeter: a case report

Background: Median arcuate ligament syndrome (MALS) is a rare surgical condition caused by external compression of the celiac artery, resulting in compromised blood flow. Intraoperative evaluation is typically based on visual findings alone, and reliable, quantitative methods for assessing surgical success remains limited. Case: A 74-year-old man was referred to our hospital with a diagnosis of early gastric cancer. Radiological findings revealed severe compression at the root of the celiac axis (CA), demonstrating the characteristic hook sign of MALS. Mild enlargement of the pancreaticoduodenal arcade arteries was observed without evidence of aneurysm formation. Concurrent surgery for gastric cancer and MALS was performed. A transit-time flowmeter (TTFM; Transonic Systems) revealed a mean flow of −119 mL/min in the common hepatic artery (CHA), indicating retrograde blood flow. After releasing the compression of the CA, the blood flow in the CHA was restored, with a mean flow of 317 mL/min. The postoperative course was uneventful, and the patient was discharged on postoperative day 21. Postoperative CT showed enlargement of the CA; however, the root lumen diameter remained smaller than that of the midsection of the CHA. Conclusion: The TTFM effectively detected retrograde blood flow in the CHA and its recovery after decompression. It may serve as a reliable method for determining the indication for MALS surgery and for evaluating surgical success intraoperatively.