One Anastomosis Gastric Bypass versus Roux-en-Y Gastric Bypass: A Randomized Prospective Trial

Background and Objectives: One anastomosis gastric bypass (OAGB) and Roux-en-Y gastric bypass (RYGB) surgeries are effective methods used in bariatric surgery. There are limited randomized studies comparing these procedures over more than 2 years. Here, we aimed to compare the 3-year results of two bariatric procedures. Materials and Methods: Patients included in this randomized prospective study were compared in OAGB and RYGB groups. A total of 55 patients, aged between 18 and 65, were eligible for the study. Thirteen patients who did not accept randomization were excluded. Patients were evaluated at 6, 12, 24, and 36 months postoperatively. Results: Three patients were excluded from the study due to loss of communication during the clinical follow-up and one due to death by amyotrophic lateral sclerosis, which started in the eighth month after surgery. The study was completed with a total of 38 patients (OAGB; n = 20, RYGB; n = 18). Patients in the two groups were similar in terms of age, gender, body mass index (BMI), and obesity-related comorbidities. At the end of 3-year follow-up, BMI in the OAGB and RYGB groups was 28.80 ± 4.53 kg/m² and 29.17 ± 5.36 kg/m², respectively (p = 0.822). Percentage total weight loss (TWL%) was similar. No significant differences were found between the groups regarding percentage excess weight loss (EWL%). Remission of comorbidities was similar. De novo refluxes developed in four OAGB patients; there were no occurrences of these in RYGB patients (p = 0.066). Conclusions: Both OAGB and RYGB are effective in the treatment of morbid obesity. The two procedures are similarly successful in terms of obesity-related comorbidities.