Scoping Review of Reflux after Primary One Anastomosis Gastric Bypass: Navigating the Maze to Enhance the Evidence Base

Reflux after primary one anastomosis gastric bypass (OAGB) remains controversial. Despite this, no review has holistically examined and narrated the post-OAGB reflux construct, problematizing its interlacing parameters to contribute better understandings of the possible sources/reasons behind the controversies. Using three electronic databases, a scoping review of the literature explored seven interlaced questions addressing the post-OAGB reflux construct. A total of 113 items were included. Our main findings include: (1) Terminology – multiple terms describing piece-meal features of the reflux notion; (2) Timing – needed to distinguish new-onset reflux vs. post-operative changes in pre-operative reflux; (3) Diagnostics – wide variety used to different extents alone or in combinations, exhibiting various levels of certainty, and with needed clarity about, rationale, choice, and diagnostic accuracy/ies; (4) Frequency of surveillance – many propositions, wide variations, and unclear rationale regarding the pre-emptive screening; (5) Length of follow up – web of possible time durations of monitoring patients, with ambiguity about how these were determined or guided; (6) Potential confounders – lack of clarity on how H. pylori, proton pump inhibitors, and hiatal hernia could in/directly influence reflux appraisals and how to consider such effects in analyses; and, (7) Relevance/utility of clinical symptoms as indicators – deficient, with occasional ad hoc descriptions but no systematic appraisal of the dynamic relationships between the reflux notion/lack thereof and symptoms/lack thereof. Implications of the findings and potential avenues for a stronger evidence base are discussed.