Indications and Outcomes of Conversion of Sleeve Gastrectomy to Roux-en-Y Gastric Bypass: a Systematic Review and a Meta-analysis

Purpose Sleeve gastrectomy (SG) is the most performed bariatric procedure. Conversion to Roux-en-Y gastric bypass (RYGB) for SG-related complications such as gastroesophageal reflux disease (GERD), insufficient weight loss (ISWL), and weight regain (WR) is increasing. Our aim was to investigate the safety, efficacy, and outcomes of conversion from SG to RYGB. Methods A literature search was performed from database inception to May 2020. Eligible studies must report indications for conversion, %total body weight loss (%TWL), and/or complications. The pooled mean or proportion were analyzed using a random-effects model. Results Seventeen unique studies (n = 556, 68.7% female, average age at time of conversion 42.6 ± 10.29 years) were included. The pooled conversion rate due to GERD was 30.4% (95% CI 23.5, 38.3%; I 2 = 63.9%), compared to 52.0% (95% CI 37.0, 66.6%; I 2 = 85.89%) due to ISWL/WR. The pooled baseline BMI at conversion was 38.5 kg/m 2 (95% CI 36.49, 40.6 kg/m 2 ; I 2 = 92.1%) and after 1 year was 32.1 kg/m 2 (95% CI 25.50, 38.7 kg/m 2 ; I 2 = 94.53%). The pooled %TWL after 1 year was 22.8% (95% CI 13.5, 32.1%; I 2 = 98.05%). Complication rate within 30 days was 16.4% (95% CI 11.1, 23.6%; I 2 = 57.17%), and after 30 days was 11.4% (95% CI 7.7, 16.7%; I 2 = 0%). Conclusion This meta-analysis showed that conversion from SG to RYGB is an option for conversion at a bariatric care center that produces sufficient weight loss outcomes, and potential resolution of symptoms of GERD. Further indication-based studies are required to obtain a clearer consensus on the surgical management of patients seeking RYGB following SG. Graphical abstract