Update on esophageal function, acid and non-acid reflux after one-anastomosis gastric bypass (OAGB): high-resolution manometry, impedance-24-h pH-metry, and gastroscopy in a prospective mid-term study

BackgroundOne-anastomosis gastric bypass (OAGB) is the third most common metabolic/bariatric procedure worldwide. A point for discussion regarding OAGB is acid and non-acid reflux in mid- and long-term follow-up. The aim of this study was to objectively evaluate reflux and esophagus motility by comparing pre- and postoperative results of 24-h pH-metry, high-resolution manometry (HRM), and gastroscopy.SettingCross-sectional study and university hospital based.MethodsThis study includes primary OAGB patients operated at the Medical University of Vienna before 31st December 2022. After a mean follow-up of 4.1 +/- 2.9 years, the preoperative examinations were repeated. Additionally, history of weight, remission of obesity-related complications (ORC), and quality of life (QOL) were evaluated.ResultsA total of 50 patients were included in this study and went through all examinations. Preoperative weight was 125.5 +/- 21.0 kg with a BMI of 44.6 +/- 5.4 kg/m2 and total weight loss after 4.1 +/- 2.9 years was 37.1 +/- 8.1%. Remission of ORC and QOL outcomes was successful in all categories. Gastroscopy showed anastomositis, esophagitis, Barrett's esophagus, and bile in the pouch in 38.0%, 34.0%, 6.0%, and 48.0%, respectively. In HRM, the postoperative lower esophageal sphincter pressure was 29.6 +/- 15.1 mmHg (unchanged to preoperative). The total number of refluxes was equal to preoperative, whereas decreased acid refluxes were replaced by increasing non-acid refluxes. Impedance-24-h pH-metry showed that acid exposure time of the esophagus and DeMeester score decreased significantly to 1.6 +/- 1.4% (p = 0.001) and 10.3 +/- 9.6 (p = 0.046).ConclusionThis study has shown decreased rates of acid reflux and increased rates of non-acid reflux after a mid-term outcome of primary OAGB patients. Gastroscopy showed significant signs of chronic reflux exposure of the anastomosis, the pouch, and the distal esophagus, even in asymptomatic patients. General follow-up visits in patients after OAGB should be considered.