Reflux After One-Anastomosis Gastric Bypass Surgery? A Narrative Review

Background: One-anastomosis gastric bypass (OAGB), also known as mini-gastric bypass, is a popular and effective bariatric procedure for morbid obesity. It offers weight loss comparable to Roux-en-Y gastric bypass (RYGB) while providing technical simplicity. However, concerns remain about the risk of biliary reflux into the gastric pouch and esophagus, which may lead to esophagitis or adenocarcinoma. This narrative review aimed to synthesize evidence on biliary reflux in OAGB, focusing on diagnostic methods and incidence rates. Methods: The data were collected from PubMed and Google Scholar using terms such as "OAGB," "mini-gastric bypass," and "biliary reflux." The review focused on diagnostic approaches and reported outcomes. Results: Diagnostic tools for detecting biliary reflux included hepatobiliary iminodiacetic acid scintigraphy, fiberoptic spectrophotometric bilirubin monitoring, gastroesophageal fluid aspiration, multichannel intraluminal impedance-pH monitoring, and intraluminal gamma detection, offering unique advantages for identifying acid and non-acid reflux over short- or long-term periods. Scintigraphy revealed that biliary reflux to the gastric pouch was common in 68% of cases, while esophageal involvement was rare (2–3%). Symptomatic or endoscopic findings were low, with esophagitis and ulcers reported in 13% and 10% of cases. Revisional surgeries for refractory reflux were infrequent (0.94–3%) and often managed through Braun anastomosis or fundoplication, achieving high success rates. Comparisons with RYGB revealed similar reflux frequencies. Long-term oncologic risks were minimal, with no reported increase in cancer incidence. Conclusion: While asymptomatic reflux presents diagnostic challenges, OAGB remains a safe bariatric option. Further randomized trials should evaluate preventive strategies and routine screening protocols.