Five-Year Endoscopic Outcomes After One-Anastomosis Gastric Bypass: A Multicenter Cohort with Bile Reflux, Marginal...

One-anastomosis gastric bypass (OAGB) is increasingly adopted worldwide as a primary bariatric procedure. Concerns persist regarding long-term gastroesophageal reflux disease (GERD), bile reflux, and postoperative mucosal injury. We evaluated 5-year endoscopic and histological outcomes after OAGB and their correlation with symptoms and preoperative risk factors.

We analyzed 1,172 patients undergoing OAGB at four high-volume bariatric centers between July 2015 and February 2020. Patients with major perioperative complications, reoperations, or incomplete follow-up were excluded. Clinical assessment included the GERD-Health-Related Quality-of-Life (GERD-HRQL) questionnaire and a modified Gastrointestinal Symptom Rating Scale (GSRS) focusing on abdominal pain. Upper endoscopy (UE) with systematic biopsy of the gastric pouch was performed according to a standardized protocol.

Mean follow-up was 62 ± 26 months (range 60-84). Mean BMI decreased from 44.31 ± 6.28 kg/m² to 25.1 ± 11.4 kg/m², with %EWL 73.2 ± 22.9% and %TWL 42.6 ± 8.5%. GERD-HRQL scores were 25-29 in 26.4% and > 30 in 17.6%; among patients with scores > 30, only 35.1% had endoscopic esophagitis. Los Angeles grade A-B esophagitis was observed in 7.7%, with no cases of Barrett's esophagus. Endoscopic gastric pouch gastritis (≥ grade 1) was detected in 27.7%, whereas histology showed at least mild inflammation in 38.8% (p < 0.001). Postoperative Helicobacter pylori infection occurred in 5.4% and was associated with histological gastritis, together with smoking and alcohol consumption ≥ 3 times/week. Anastomotic ulceration occurred in 2.6%, predominantly in heavy smokers, and three cases required surgical revision.

At 5 years, OAGB provides durable weight loss with low rates of erosive esophagitis. However, gastric pouch gastritis and anastomotic ulcers remain clinically relevant, particularly in patients with modifiable risk factors; targeted endoscopic surveillance and risk-factor management may reduce long-term mucosal injury.