OAGB 2025. A systematic review with meta-analysis of indications and results for primary procedures at 5+ years.

One-anastomosis gastric bypass (OAGB) has gained increasing popularity as a metabolic and bariatric procedure due to its technical simplicity, promising weight loss and metabolic outcomes. However, its indications, long-term efficacy and long-term safety, remain the subject of an ongoing investigation. A systematic review of retrospective and prospective studies evaluating OAGB with a follow-up of minimum five years was conducted. 22 studies encompassing a total of 14,692 patients were included. The analysis included data on patient demographics, surgical indications, comorbidities, weight loss outcomes, and post-operative complications. Studies varied in design, with case numbers ranging from 101 to 2678 patients. Mean follow-up was 89.04 months (min 60 months, max 180 months). Patient age range was 33.8 to 47 years. Body mass index at surgery was between 33.4 and 54 kg/m². Total weight loss rate ranged from 24.62% to 48.80% and excess weight loss percentage reached up to 94%, showing diabetes remission between 36.4% and 100%, hypertension resolution from 17% to 90.9%, and dyslipidemia improvement in up to 90% of cases. Long-term complications included anemia (1%), hypoalbuminemia (0.09%), marginal ulcers (0.19-7.7%), and bile reflux (0.8-9.8%). The necessity for revisional surgery was from 0.19 to 5.21%. OAGB appears to be an effective metabolic and bariatric procedure with high rates of weight loss and metabolic improvement in the long term. However, careful patient selection, nutritional monitoring, and long-term follow-up are essential to mitigate risks, such as anemia, hypoalbuminemia, marginal ulcers, and bile reflux. Further prospective, multicentric studies are warranted to establish standardized indications and optimize patient outcomes.