Esophageal function and non-acid reflux evaluated by impedance-24 h-pH-metry, high-resolution manometry, and gastroscopy after one-anastomosis gastric bypass—outcomes of a prospective mid-term study

BACKGROUND: One-Anastomosis Gastric Bypass (OAGB) is the third most common bariatric operation for patients with obesity worldwide. One concern about OAGB is the presence of acid and non-acid reflux in a mid- and long-term follow-up. The aim of this study was to objectively evaluate reflux and esophagus motility by comparing preoperative and postoperative mid-term outcomes. SETTING: Cross-sectional study; University-hospital based. METHODS: This study includes primary OAGB patients (preoperative gastroscopy, high-resolution manometry (HRM), and impedance-24 h-pH-metry) operated at Medical University of Vienna before 31st December 2017. After a mean follow-up of 5.1 ± 2.3 years, these examinations were repeated. In addition, history of weight, remission of associated medical problems (AMP), and quality of life (QOL) were evaluated. RESULTS: A total of 21 patients were included in this study and went through all examinations. Preoperative weight was 124.4 ± 17.3 kg with a BMI of 44.7 ± 5.6 kg/m(2), total weight loss after 5.1 ± 2.3 years was 34.4 ± 8.3%. In addition, remission of AMP and QOL outcomes were very satisfactory in this study. In gastroscopy, anastomositis, esophagitis, Barrett´s esophagus, and bile in the pouch were found in: 38.1%, 28.3%, 9.5%, and 42.9%. Results of HRM of the lower esophageal sphincter pressure were 28.0 ± 15.6 mmHg, which are unchanged compared to preoperative values. Nevertheless, in the impedance-24 h-pH-metry, acid exposure time and DeMeester score decreased significantly to 1.2 ± 1.2% (p = 0.004) and 7.5 ± 8.9 (p = 0.017). Further, the total number of refluxes were equal to preoperative; however, the decreased acid refluxes were replaced by non-acid refluxes. CONCLUSION: This study has shown decreased rates of acid reflux and increased non-acid reflux after a mid-term outcome of primary OAGB patients. Gastroscopy showed signs of chronic irritation of the gastrojejunostomy, pouch, and distal esophagus, even in asymptomatic patients. Follow-up gastroscopies in OAGB patients after 5 years may be considered. GRAPHICAL ABSTRACT: [Image: see text]