Effectiveness of Transoral Outlet Reduction Post-Roux-en-Y Gastric Bypass Beyond the One-Year Benchmark: A Systematic...

Transoral outlet reduction (TORe) is increasingly performed for recurrent weight gain or suboptimal clinical response after Roux-en-Y gastric bypass (RYGB). However, the durability of outcomes beyond one year remains uncertain.

A systematic review and meta-analysis was conducted following PRISMA guidelines. Six databases were searched to June 2025 for RCTs and cohort studies of adults undergoing TORe after RYGB with ≥ 12 months of follow-up. Outcomes included % total weight loss (%TWL), % excess weight loss (%EWL), and adverse events (AEs). Data were pooled using random effects restricted maximum likelihood models.

Twenty-five studies (3 RCTs, 22 observational; 2667 patients) were included. Pooled baseline age was 47.3 years, 86.0% were female, mean BMI was 38.0 kg/m², and mean interval from RYGB to TORe was 9.5 years. At 12 months, pooled %TWL was 8.0% (95% CI 6.3-9.7) and pooled %EWL was 20.3% (95% CI 14.1-26.5). Weight loss declined at longer follow-up, with pooled estimates of 7.7% TWL and 16.3% EWL at 24 months, and 4% TWL at 36 months. In meta-regression, years since RYGB predicted greater %TWL and %EWL. The pooled AE rate was 5% (95% CI 3-7%), and the pooled SAE rate was 0.3% (95% CI 0.1-0.5%), with no procedure-related mortality.

TORe can provide modest but clinically meaningful weight loss at 12 months with a low rate of serious AE although durability beyond two years appears limited. It may be best regarded as an anatomically corrective intervention that is most effective when incorporated into comprehensive, long-term obesity management.