Minimally Invasive Hypoabsorptive Bariatric Surgery – A Systematic Review and Network Meta-Analysis of Randomized Clinical Trials

Background: The optimal hypoabsorptive surgical approach for management of severe obesity remains unclear. Aim: To perform a network meta-analysis (NMA) of randomized clinical trials (RCTs) comparing Roux-en-y gastric bypass (RYGB), SADI-S (single anastomosis duodeno-ileal bypass with sleeve gastrectomy), one anastomosis gastric bypass (OAGB) and duodenal switch (DS). Methods: A systematic review was performed as per PRISMA-NMA guidelines. Statistical analyses were performed using R and shiny. Results: 12 RCTs (with 5 sequential analyses) were included, involving 986 patients [471 RYGB (47.8%), 341 OAGB (34.6%), 145 DS (14.7%), and 29 SADI-S (2.9%)]. Patient age, gender, BMI, and ASA grade were similar (all P > 0.050). Patient follow-up ranged from 1.0-15.4 years. Compared to RYGB, DS [mean difference (MD): -13.9, 95% confidence interval (CI): -18.7; -9.1) and SADI-S (MD: -12.4, 95% CI: 19.8; 5.0) significantly increased total body weight loss, while DS (MD: -10.5, 95% CI: -13.1; -7.9), OAGB (MD: -3.1, 95% CI: -5.1; -1.2) and SADI-S (MD: -8.1, 95% CI: -16.1; -0.1) significantly increased excess body weight loss. Relative to RYGB, DS (MD: -24.9, 95% CI: -28.3; -21.5) and OAGB (MD: -1.8, 95% CI: -3.4; -0.3) significantly increased weight loss, while DS (MD: -13.6, 95% CI: -16.0; -11.2) and SADI-S (MD: -16.0, 95% CI: -23.62; -8.38) significantly increased excess weight loss. Importantly, DS (MD: 2.1, 95% CI: 0.1; 4.0) significantly increased length of stay while OAGB was associated with long-term severe malabsorption rates. Conclusion: DS, SADI-S and OAGB all serve in significantly inducing weight loss, albeit results in support of SADI-S are limited due to a small sample size. Nevertheless, based on the data presented in this study, there is no consensus as to the optimal hypoabsorptive bariatric surgical approach.