A Meta-Analysis Comparing RYGB with Long Biliopancreatic Limb (BPL) Versus Long Alimentary Limb (AL) in Groups with Equal or Nearly Equal Combined Bypass Lengths (Combined BPL and AL Lengths): Does Switching Seats Enhance Weight Loss?

It is well-established that extending either the biliopancreatic limb (BPL), the alimentary limb (AL), or both, results in increased combined bypass (CB) length, which in turn leads to enhanced weight loss and potential nutritional deficiencies due to heightened malabsorptive effects. However, a key question remains: Assuming no change in CB length, does altering BPL length affect outcomes? To address this question, we examined studies comparing long BPL and long AL (short BPL) while maintaining equal or nearly equal CB lengths. We conducted this systematic literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a meta-analysis on weight loss outcomes, adverse events and safety-related outcomes, gastrointestinal complaints, and nutritional outcomes at the 2-year mark.