Factors influencing the outcome of magnetic sphincter augmentation for chronic gastroesophageal reflux disease

Objectives: Magnetic sphincter augmentation (MSA) is a surgical treatment option for patients with gastroesophageal reflux disease (GERD). MSA consistently improves quality of life, maintains freedom from PPIs, and objectively controls GERD. However, up to 24% of patients did not achieve these outcomes. We sought to identify factors predicting outcomes after MSA placement with the aim of refining selection criteria. Methods: We retrospectively analyzed clinical, endoscopic, manometric, pH data, and intraoperative factors from two databases: Pivotal Trial (N = 99) and our prospectively maintained esophageal database (N = 71). A priori outcomes were defined as excellent (GERD-HRQL <5, no PPI, no esophagitis), good (GERD-HRQL 6–15, no PPI, grade A esophagitis), fair (GERD-HRQL 16 to 25, PPI use, grade B esophagitis), and poor (GERD-HRQL >25, PPI use, grade C/D esophagitis). Univariable and multivariable logistic regression analyses were performed to determine predictors of achieving an excellent/good outcome. Results: A total of 170 patients underwent MSA with a median age of 53 years, [43–60] and a median BMI of 27 (IQR = 24–30). At baseline, 93.5% of patients experienced typical symptoms and 69% atypical symptoms. Median DeMeester score was 37.9 (IQR 27.9–51.2) with a structurally intact sphincter in 47%. Esophagitis occurred in 43%. At 48 [19–60] months after MSA, excellent outcomes were achieved in 47%, good in 28%, fair in 22%, and poor in 3%. Median DeMeester score was 15.6 (IQR = 5.8–26.6), esophagitis in 17.6% and daily PPI use in 17%. At univariable analysis, excellent/good outcomes were negatively impacted by BMI, preoperative LES residual pressure, Hill grade, and hiatal hernia. At multivariable analysis, BMI >35 (OR = 0.05, 0.003–0.78, p = 0.03), structurally defective LES (OR = 0.37, 0.13–0.99, p = 0.05), and preoperative LES residual pressure (OR = 0.89, 0.80–0.98, p = 0.02) were independent negative predictors of excellent/good outcome. Conclusions: Magnetic sphincter augmentation results in excellent/good outcomes in most patients but a higher BMI, structurally defective sphincter, and elevated LES residual pressure may prevent this goal.