The Complexities of Reoperative Metabolic and Bariatric Surgery–A Retrospective Review of Outcomes at a Single Large Institution

BACKGROUND: Reoperative metabolic and bariatric surgery (MBS), consisting of revision and conversion surgery, carries higher morbidity and mortality compared with primary procedures, yet robust long-term data are limited. METHODS: A retrospective review was conducted of all patients 18 years of age or older who underwent first-time reoperative MBS between 2000 and 2024 at a single large quaternary referral center. Data were stored securely and analyzed in R (v4.4.2) using standard descriptive statistics and group tests ( t tests/Wilcoxon/Kruskal-Wallis; χ²/Fisher). Sparse late-complication data precluded pairwise tests. RESULTS: Three hundred sixty patients, 86% female, mean age 50 years, underwent reoperative MBS. Conversion to Roux-en-Y gastric bypass (49%) was the most common surgery. The majority were performed for weight recidivism (37%). Length of stay, estimated blood loss, length of surgery, complication rates, readmission rates, and reintervention rates varied by type of reoperative MBS performed and indication. Most early complications were Clavien-Dindo 2, and most late complications were Clavien-Dindo 3b for all approaches. There was one procedure-related death in the study following an open conversion. CONCLUSION: In this 24-year single-center cohort, weight recidivism was the most frequent indication for reoperation and was associated with improved perioperative outcomes and durable long-term weight loss. As the landscape of bariatric surgery continues to evolve, we recommend early referral to centers with reoperative MBS expertise.