Efficacy and safety of single-anastomosis gastric bypass variants versus sleeve gastrectomy or Roux-en-Y gastric bypass: a systematic review and meta-analysis

Single-anastomosis gastric bypass variants, collectively termed sleeve gastrectomy with transit bipartition (SG-TB), have emerged as simplified metabolic procedures. This meta-analysis compares the efficacy and safety of SG-TB against sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). We systematically searched multiple databases through September 2025 for comparative studies. Random-effects models were used for meta-analysis, calculating mean differences (MD) and odds ratios (OR) with 95% confidence intervals (CI). Twenty studies were included. Compared to SG, SG-TB resulted in significantly greater 1-year total weight loss (TWL MD = 3.5%, CI 1.5–5.5%) and excess weight loss (EWL MD = 10.8%, CI 8.6–13.0%). For type 2 diabetes remission, SG-TB showed a positive trend but with substantial uncertainty (OR = 2.74, CI 0.61–12.32). SG-TB demonstrated significantly higher GERD remission rates versus SG (OR = 6.90, CI 1.98–24.09). Weight loss and diabetes remission were comparable between SG-TB and RYGB. Nutritional assessment revealed generally comparable profiles, with SG-TB showing better iron/vitamin B12 preservation versus RYGB but lower vitamin D levels versus SG. SG-TB had a comparable short-term safety profile to both SG and RYGB, with no significant differences in perioperative complications, despite a longer operative time versus SG. SG-TB procedures offer superior weight loss compared to SG and achieve metabolic outcomes equivalent to RYGB, with a comparable short-term safety profile. The substantial uncertainty in diabetes remission estimates against SG warrants cautious interpretation. These findings position SG-TB as a compelling and effective surgical option for severe obesity and related metabolic disease.