Guideline sources The following summarized guidelines for the evaluation and management of median arcuate ligament syndrome (MALS) are prepared by our editorial team based on guidelines from the Society for Vascular Surgery (SVS 2021; 2020) and the European Association for Gastroenterology, Endoscopy and Nutrition (EAGEN/CIRSE/NVMDL/HSGO/UEG/DMIS/ESGAR 2020). 1 2 3 Guidelines 1. Screening and diagnosis Differential diagnosis: As per SVS 2021 guidelines, obtain an expedited workup to exclude gastrointestinal malignancies and other potential causes in patients with abdominal pain, weight loss, and fear of food, including investigations such as: upper and lower gastrointestinal endoscopy abdominal CT abdominal ultrasound. B As per UEG 2020 guidelines, obtain at least the following diagnostic tests to exclude alternative diagnoses in patients with suspected chronic mesenteric ischemia: upper gastrointestinal endoscopy https://web.pathway.md/diseases/recd1qbzSuxYa462E 1/3 6/30/23, 1:00 AM Median arcuate ligament syndrome Pathway upper gastrointestinal endoscopy lower gastrointestinal endoscopy (depending on age and symptoms, but is mandatory in patients with diarrhea) abdominal imaging (CT/MRI). B 2. Diagnostic investigations Diagnostic imaging: Obtain inspiration/expiration duplex ultrasound, CT angiography, or contrast-enhanced MRA for the diagnosis of celiac artery compression in MALS. B Obtain duplex ultrasound or contrast-enhanced MRA ( 2 mm slices with 3D reconstructions) in inspiration and expiration in younger patients with suspected MALS. B Screening for mesenteric aneurysms: consider obtaining CT angiography or duplex ultrasound for the screening of gastroduodenal artery and pancreaticoduodenal artery aneurysms in patients with MALS. C 3. Therapeutic procedures Celiac artery stenting: do not perform endovascular stenting of the celiac artery in patients with MALS (and no preceding adequate celiac artery release). D 4. Surgical interventions Celiac artery release: consider performing surgical celiac artery release in patients with MALS. C Clinical findings Symptoms Past medical history Abdominal pain Gastroduodenal artery aneurysm Bloating Gastroparesis Chest pain Pancreaticoduodenal artery aneurysm Diarrhea Epigastric pain Fear of food Imaging findings Loss of appetite Celiac artery stenosis Nausea Hook-shaped celiac trunk Postprandial abdominal pain Postprandial fullness Vomiting https://web.pathway.md/diseases/recd1qbzSuxYa462E 2/3 6/30/23, 1:00 AM Median arcuate ligament syndrome Pathway Weight loss Vascular exam References 1. Thomas S Huber, Martin Bj rck, Ankur Chandra et al. Chronic mesenteric ischemia: Clinical practice guidelines from the Society for Vascular Surgery. Vasc Surg. 2021 Jan;73 1S 87S 115S. Open 2. Rabih A Chaer, Christopher J Abularrage, Dawn M Coleman et al. The Society for Vascular Surgery clinical practice guidelines on the management of visceral aneurysms. J Vasc Surg. 2020 Jul;72 1S 3S 39S. Open 3. Luke G Terlouw, Adriaan Moelker, Jan Abrahamsen et al. European guidelines on chronic mesenteric ischaemia - joint United European Gastroenterology, European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Gastrointestinal and Abdominal Radiology, Netherlands Association of Hepatogastroenterologists, Hellenic Society of Gastroenterology, Cardiovascular and Interventional Radiological Society of Europe, and Dutch Mesenteric Ischemia Study group clinical guidelines on the diagnosis and treatment of patients with chronic mesenteric ischaemia. United European Gastroenterol J. 2020 May;8 4 371 395. Open https://web.pathway.md/diseases/recd1qbzSuxYa462E 3/3