Transoral Outlet Reduction (TORe) in Treating Dumping Syndrome after Roux-en-Y Gastric Bypass (RYGB) - A Systematic Review and Meta-Analysis

Background: Dumping syndrome (DS) is a frequent complication after Roux-en-Y gastric bypass (RYGB), causing gastrointestinal and neurohumoral symptoms that can significantly affect quality of life. Transoral outlet reduction (TORe) has been used in clinical practice as a therapy of DS alongside other conservative and surgical approaches. Effectiveness of different therapy options remain unclear. With this meta-analysis, we aim to create an overview over the available data concerning TORe. Methods: We conducted a meta-analysis including ten retrospective studies identified through a literature search in five databases. All studies analyzed the resolution of dumping syndrome symptoms after TORe through evaluation of Sigstad Score. Results: The literature search yielded 1,014 publications, of which ten retrospective studies involving a total of 320 patients met the inclusion criteria for this meta-analysis. The analysis showed that TORe led to a pooled success rate of 95.59%, significant weight loss (p<0.001), and an average reduction of Sigstad score by 8.71 points, indicating a consistent improvement in the severity of DS (p<0.001). Conclusion: This meta-analysis demonstrates that TORe can be an effective, endoluminal treatment option for DS following RYGB. However, limitations include the retrospective nature of the studies, lack of long-term follow-up, and inconsistent outcome measures. No distinction between early and late DS was observed in any of the included trials. Future research should focus on prospective trials, standardised outcomes and comparisons with surgical options, in order to fully assess the efficacy and durability of TORe. We suggest using additional objective primary outcome measures, such as oral glucose tolerance testing (OGTT) and continuous glucose monitoring (CGM).