Mechanisms of Gastroesophageal Reflux Post-Roux-en-Y Gastric Bypass: Universal Alteration of the Antireflux Barrier is the Culprit.

INTRODUCTION: Gastroesophageal reflux disease (GERD) symptoms and the use of proton pump inhibitors (PPIs) remain prevalent after Roux-en-Y Gastric Bypass (RYGB), despite it being known to alleviate reflux. The physiological changes behind long-term GERD and hiatal hernia (HH) prevalence post-RYGB are not commonly investigated. METHODS: In this consecutive cohort study, we examined patients who underwent RYGB and subsequent upper endoscopy, conducted by an expert bariatric endoscopist. The primary focus was on pouch endoscopic retrosflexion to evaluate the antireflux barrier (ARB). We gathered data encompassing patient demographics, anthropometrics, comorbidities, and findings from esophagogastroduodenoscopy (EGD) at the time of surgery and during follow-up EGD. RESULTS: Our study included a total of 42 patients, predominantly female (97.5%) and White (100%), with an average age of 53.6±10.6 years and a body mass index (BMI) of 32.9±9.4 kg/m2. In our findings, all EGDs revealed the presence of a HH of varying sizes. The average HH size was 2.07±0.87 cm. The esophagogastric junction (EGJ) flap was also effaced in all patients with the majority (90.4%, 38 patients) classified as Hill grade IV and a smaller proportion (9.6%, 4 patients) as Hill grade III. Notably, PPI usage increased from the time of surgery to the time of EGD (69.0% vs. 42.9%, P=0.06). CONCLUSION: This research highlights the high incidence of HH and EGJ flap effacement in patients after RYGB, potentially elucidating the persistence of reflux symptoms, including weakly acidic or alkaline reflux, post-RYGB.