Background Roux-en-Y gastric bypass (RYGB) is often the preferred conversion procedure for laparoscopic adjustable gastric banding (LAGB) poor responders. However, there is controversy whether it is better to convert in one or two stages. This study aims to compare the outcomes of one and two-stage conversions of LAGB to RYGB. Methods Retrospective review of a multicenter prospectively collected database. Data on conversion in one and two stages was compared. Results Eight hundred thirty-two patients underwent LAGB conversion to RYGB in seven specialized bariatric centers. Six hundred seventy-three (81%) were converted in one-stage. Patients in the two-stage group were more likely to have experienced technical complications, such as slippage or erosions (86% vs. 37%, p = 0.0001) and to have had a higher body mass index (BMI) (41.6 vs. 39.9 Kg/m 2 , p = 0.005). There were no differences in postoperative complications and mortality rates between the onestage and two-stage groups (13.5% vs. 10.8%, and 0.7% vs. 0.0% respectively, p = ns). Mean final BMI and %total weight loss (%TWL) for the one-stage and the two-stage groups were 31.6 vs. 32.4 Kg/m 2 (p = ns) and 30.4 vs. 26.8 (p = 0.017) after a mean follow-up of 33 months. Follow-up at 1, 3, and 5 years was 98%, 75%, and 54%, respectively. Conclusions One-stage conversion of LAGB to RYGB is safe and effective. Two-stage conversion carries low morbidity and mortality in the case of band slippage, erosion, or higher BMI patients. These findings suggest the importance of patient selection when choosing the appropriate conversion approach.

Introduction One anastomosis gastric bypass (OAGB) has been proposed as a rescue technique for laparoscopic adjustable gastric banding (LAGB) poor responders. Aim We sought to analyze, complications, mortality, and medium-term weight loss results after LAGB conversion to OAGB. Methods Data analysis of an international multicenter database. Results One hundred eighty-nine LAGB-to-OAGB operations were retrospectively analyzed. Eighty-seven (46.0%) were converted in one stage. Patients operated on in two stages had a higher preoperative body mass index (BMI) (37.9 vs. 41.3 kg/ m 2 , p = 0.0007) and were more likely to have encountered technical complications, such as slippage or erosions (36% vs. 78%, p < 0.0001). Postoperative complications occurred in 4.8% of the patients (4.6% and 4.9% in the one-stage and the twostage group, respectively). Leak rate, bleeding episodes, and mortality were 2.6%, 0.5%, and 0.5%, respectively. The final BMI was 30.2 at a mean follow-up of 31.4 months. Follow-up at 1, 3, and 5 years was 100%, 88%, and 70%, respectively. Conclusion Conversion from LAGB to OAGB is safe and effective. The one-stage approach appears to be the preferred option in non-complicate cases, while the two-step approach is mostly done for more complicated cases.