Effects of omega-loop bypass on esophagogastric junction function

Background: At present, no objective data are available on the effect of omega-loop gastric bypass (OGB) on gastroesophageal junction and reflux. Objectives: To evaluate the possible effects of OGB on esophageal motor function and a possible increase in gastroesophageal reflux. Setting: University Hospital, Italy; Public Hospital, Italy. Methods: Patients underwent clinical assessment for reflux symptoms, and endoscopy plus high resolution impedance manometry (HRiM) and 24-hour pH-impedance monitoring (MII-pH) before and 1 year after OGB. A group of obese patients who underwent sleeve gastrectomy (SG) were included as the control population. Results: Fifteen OGB patients were included in the study. After surgery, none of the patients reported de novo heartburn or regurgitation. At endoscopic follow-up 1 year after surgery, esophagitis was absent in all patients and no biliary gastritis or presence of bile was recorded. Manometric features and patterns did not vary significantly after surgery, whereas intragastric pressures (IGP) and gastroesophageal pressure gradient (GEPG) statistically diminished (from a median of 15 to 9.5, P <.01, and from 10.3 to 6.4, P <.01, respectively) after OGB. In contrast, SG induced a significant elevation in both parameters (from a median of 14.8 to 18.8, P <.01, and from 10.1 to 13.1, P <.01, respectively). A dramatic decrease in the number of reflux events (from a median of 41 to 7; P <.01) was observed after OGB, whereas in patients who underwent SG a significant increase in esophageal acid exposure and number of reflux episodes (from a median of 33 to 53; P <.01) was noted. Conclusions: In contrast to SG, OGB did not compromise the gastroesophageal junction function and did not increase gastroesophageal reflux, which was explained by the lack of increased IGP and in GEPG as assessed by HRiM. (C) 2016 American Society for Metabolic and Bariatric Surgery. All rights reserved.