Gas-Bloat Syndrome after Magnetic Sphincter Augmentation: Incidence, Natural History, Risk Factors, and Impact on Surgical Outcomes Over Time

Abstract

Background: The notion that gas-bloat syndrome (GBS) after magnetic sphincter augmentation (MSA) is less detrimental, has not been substantiated by data. This study aimed to identify the incidence, natural history, risk factors and impact on outcomes of GBS after MSA. Study Design: Records of patients who underwent MSA at our institution were reviewed. GBS was defined as ≥4 on the gas-bloat-specific item within the GERD-HRQL questionnaire. Preoperative clinical and objective testing data were compared between those with and without GBS at 1-year using univariate followed by multivariable analysis. GBS evolution overtime and its impact on outcome were assessed in those with 1-year and 2-year follow-up. Results: A total of 489 patients underwent MSA. At a mean (SD) follow-up of 12.8 (2.1) months, patient satisfaction was 88.8%, 91.2% discontinued antisecretory medications and 74.2% achieved DeMeester score normalization. At 1-year, 13.3% of patients developed GBS, and had worse GERD-HRQL scores, antisecretory medication use and satisfaction (p<0.0001). DeMeester score normalization was comparable (p=0.856). Independent predictors of GBS were bloating (OR:1.8, p=0.043), GERD-HRQL score >30 (OR:3.0, p=0.0010) and MSA size ≤14 beads (OR:2.5, p=0.004). In a subgroup of 239 patients with 2-year follow-up, 70.4% of patients with GBS at 1-year had resolution by 2-years. The GERD-HRQL total score improved when GBS resolved [11 (7-19) to 7 (4-10), p=0.016]. Patients with persistent GBS at 2-years had worse 2-year GERD-HRQL total scores [20 (5-31) vs 5 (3-12) p=0.019]. Conclusion: Gas-bloat syndrome affects 13.3% of patients at 1-year after MSA and substantially diminishes outcomes. However, GBS resolves spontaneously with quality of life improvement. Patients with preoperative bloating, high GERD-HRQL scores or small MSA devices are at greatest risk of this complication.