MAGNETIC SPHINCTER AUGMENTATION DEVICE FOR GASTROESOPHAGEAL REFLUX DISEASE: EFFECTIVE, BUT POSTOPERATIVE DYSPHAGIA AND RISK OF EROSION SHOULD NOT BE UNDERESTIMATED. A SYSTEMATIC REVIEW AND META-ANALYSIS.

Background: Magnetic ring (MSA) implantation in the esophagus is an alternative surgical procedure to fundoplication for the treatment of gastroesophageal reflux disease.
Aims: The aim of this study was to analyse the effectiveness and safety of magnetic sphincter augmentation (MSA) in patients with gastroesophageal reflux disease (GERD).
Methods: A systematic literature review of articles on MSA was performed using the Medical Literature Analysis and Retrieval System Online (Medline) database between 2008 and 2021, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effect model was used to generate a pooled proportion with 95% confidence interval (CI) across all studies.
Results: A total of 22 studies comprising 4,663 patients with MSA were analysed. Mean follow-up was 27.3 (7-108) months. The weighted pooled proportion of symptom improvement and patient satisfaction were 93% (95%CI 83-98%) and 85% (95%CI 78-90%), respectively. The mean DeMeester score (pre-MSA: 34.6 vs. post-MSA: 8.9, p=0.03) and GERD-HRQL score (pre-MSA: 25.8 vs. post-MSA: 4.4, p<0.0001) improved significantly after MSA. The proportion of patients taking proton pump inhibitor (PPIs) decreased from 92.8 to 12.4% (p<0.0001). The weighted pooled proportions of dysphagia, endoscopic dilatation and gas-related symptoms were 18, 13, and 3%, respectively. Esophageal erosion occurred in 1% of patients, but its risk significantly increased for every year of MSA use (odds ratio - OR 1.40, 95%CI 1.11-1.77, p=0.004). Device removal was needed in 4% of patients.
Conclusions: Although MSA is a very effective treatment modality for GERD, postoperative dysphagia is common and the risk of esophageal erosion increases over time. Further studies are needed to determine the long-term safety of MSA placement in patients with GERD.