Bariatric surgery: a systematic review and network meta-analysis of randomized trials

The clinical efficacy and safety of bariatric surgery trials were systematically reviewed. MEDLINE, EMBASE, CENTRAL were searched to February 2009. A basic PubCrawler alert was run until March 2010. Trial registries, HTA websites and systematic reviews were searched. Manufacturers were contacted. Randomized trials comparing bariatric surgeries and/or standard care were selected. Evidence-based items potentially indicating risk of bias were assessed. Network meta-analysis was performed using Bayesian techniques. Of 1838 citations, 31 RCTs involving 2619 patients (mean age 30-48 y; mean BMI levels 42-58 kg/m(2) ) met eligibility criteria. As compared with standard care, differences in BMI levels from baseline at year 1 (15 trials; 1103 participants) were as follows: jejunoileal bypass [MD: -11.4 kg/m(2) ], mini-gastric bypass [-11.3 kg/m(2) ], biliopancreatic diversion [-11.2 kg/m(2) ], sleeve gastrectomy [-10.1 kg/m(2) ], Roux-en-Y gastric bypass [-9.0 kg/m(2) ], horizontal gastroplasty [-5.0 kg/m(2) ], vertical banded gastroplasty [-6.4 kg/m(2) ], and adjustable gastric banding [-2.4 kg/m(2) ]. Bariatric surgery appears efficacious compared to standard care in reducing BMI. Weight losses are greatest with diversionary procedures, intermediate with diversionary/restrictive procedures, and lowest with those that are purely restrictive. Compared with Roux-en-Y gastric bypass, adjustable gastric banding has lower weight loss efficacy, but also leads to fewer serious adverse effects.