Comparative Outcomes of Single-Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy Versus Roux-en-Y Gastric Bypass in Adults with Severe Obesity: A Systematic Review and Meta-Analysis.

Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is increasingly used for severe obesity, but its comparative effectiveness versus Roux-en-Y gastric bypass (RYGB) remains uncertain. This systematic review and meta-analysis included 12 comparative studies (3,317 patients) identified through searches of major databases to April 2026. Random-effects meta-analyses suggested a potential weight-loss benefit with SADI-S compared with RYGB at selected follow-up points, while no clear differences were observed in remission of type 2 diabetes, hypertension, or dyslipidemia, or in HbA1c reduction. No clear differences were observed in operative outcomes or early complications, while the findings suggested potential reductions in reoperations and selected late surgical complications with SADI-S; a nonsignificant trend toward greater calcium deficiency was also observed. Evidence certainty was predominantly low or very low because of methodological limitations and heterogeneity. Comparative mortality could not be assessed because no included study provided mortality data suitable for pooling, highlighting the need for high-quality long-term randomized studies.