Conversion to Roux-en-Y gastric bypass versus one-anastomosis gastric bypass after a failed primary gastric band: a matched nationwide study

Background: Primary laparoscopic adjustable gastric band (LAGB) has high rates of patients not achieving the desired weight loss, and it remains unclear which bariatric conversion procedure gives better results. Objective: To compare weight loss among patients undergoing conversion one-anastomosis gastric bypass (cOAGB) and conversion Roux-en-Y gastric bypass (cRYGB) after a failed LAGB. Setting: Nationwide population-based study including all 18 hospitals providing metabolic and bariatric surgery. Methods: Patients with a failed primary LAGB who underwent a cRYGB or cOAGB between January 1, 2015, and December 31, 2019, were selected from the Dutch Audit for Treatment of Obesity. The primary outcome was not achieving ≥20% total weight loss (TWL) at 1-year and up to 5-year follow-up. Secondary outcomes included postoperative complications, defined as Clavien-Dindo ≥III within 30 days, and co-morbidity remission. A propensity score matched logistic and Poisson regression model was used to estimate the difference in patients not achieving ≥20% TWL between cRYGB and cOAGB. Results: A total of 615 (78.7%) patients underwent cRYGB, and 166 (21.3%) patients underwent cOAGB, with 163 patients successfully matched. Both groups had similar rates of patients not achieving ≥20% TWL at 1 year (odds ratio [OR] = .64, 95% confidence interval [CI]: .38–1.05). However, a sensitivity analysis showed that patients undergoing cOAGB had lower rates of patients not achieving ≥20% TWL up to 5-year follow-up (rate ratio = .69, 95% CI: .51–.95, P < .05). Patients undergoing cOAGB were less likely to achieve hypertension remission (OR = .22, 95% CI: .07–.66). There were no significant differences between groups in postoperative complications (OR = .39, 95% CI: .07–2.06, P > .05). Conclusion: This matched nationwide study suggests that the cOAGB has similar short-term weight loss outcomes but potentially better long-term weight loss results than cRYGB. Therefore, cOAGB could provide a reliable alternative but needs to be substantiated in future long-term studies.