Medium-Term Outcomes from a Series of 1000 One Anastomosis Gastric Bypass in Australia: A Case Series

This study presents the short- (less than 6 months) and medium-term (6 months to 2 years) outcomes for weight loss and type 2 diabetes mellitus (T2DM) for all patients undergoing one anastomosis gastric bypass (OAGB) across multiple institutions between 2015 and 2021.

A retrospective analysis of prospectively collected databases was performed including 1022 participants who underwent OAGB at multiple institutions by multiple surgeons between 2015 and 2021. Primary outcome was percentage total weight loss (TWL) and secondary outcomes were achieving resolution of T2DM; OAGB specific short- and medium-term complications including bile reflux, marginal ulceration and internal herniation.

One thousand and twenty-two patients underwent OAGB (81% primary surgery). A percentage of 34.1% (n = 349) had a preoperative diagnosis of type 2 diabetes mellitus (T2DM). Mean TWL was 33.6 ± 9%  with a T2DM remission rate of 74% at 1-year post-op. Rates of bile reflux and marginal ulceration was 1.1% (n = 11) and 1.1% (n = 11). There were no cases of internal herniation during the follow-up period.

OAGB results has echoed previously published work as being efficacious and safe in a short-medium term. The prevalence of complications, especially bile reflux is overall low in our population and no current evidence exists to support an increased risk of metaplasia or malignancy related to bile within the stomach.