Systematic Review of the Efficacy of Treatment for Median Arcuate Ligament Syndrome

Objective: Since the first description of the median arcuate ligament syndrome (MALS), the existence for the syndrome and the efficacy of treatment for it have been questioned. Methods: A systematic review conforming to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement was conducted, with a broader view on treatment for MALS including any kind of coeliac artery release, coeliac plexus resection, and coeliac plexus blockage, irrespective of age. Online databases were used to identify papers published between 1963 and July 2021. The inclusion criteria were abdominal symptoms, proof of MALS on imaging, and articles reporting at least three patients. Primary outcomes were symptom relief and quality of life (QoL). Results: Thirty-eight studies describing 880 adult patients and six studies describing 195 paediatric patients were included. The majority of the adult studies reported symptom relief of more than 70% from three to 228 months after treatment. Two adult studies showed an improved QoL after treatment. Half of the paediatric studies reported symptom relief of more than 70% from six to 62 months after laparoscopic coeliac artery release, and four studies reported an improved QoL. Thirty-five (92%) adult studies and five (83%) paediatric studies scored a high or unclear risk of bias for the majority of the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) items. The meaning of coeliac plexus resection or blockage could not be substantiated. Conclusion: This systematic review suggests a sustainable symptom relief of more than 70% after treatment for MALS in the majority of adult and paediatric studies; however, owing to the heterogeneity of the inclusion criteria and outcome parameters, the risk of bias was high and a formal meta-analysis could not be performed. To improve care for patients with MALS the next steps would be to deal with reporting standards, outcome definitions, and consensus descriptions of the intervention(s), after which an appropriate randomised controlled trial should be performed.