Esophageal Pathophysiologic Changes and Adenocarcinoma After Bariatric Surgery: A Systematic Review and Meta-Analysis

INTRODUCTION: To assess the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) on acid reflux and esophageal motor function and to evaluate the observation of esophageal adenocarcinoma (EAC) after bariatric surgery. METHODS: We searched 5 databases for adults who underwent SG or RYGB and had esophageal pH test and/or esophageal manometry before and after surgery. A separate systemic search of observational studies and a retrospective review at 3 institutions of adults who developed EAC after these surgeries were conducted. Outcomes were changes in manometric and pH parameters and EAC cases after SG and RYGB. RESULTS: A total of 27 nonrandomized studies (SG: 612 patients; RYGB: 470 patients) were included. After SG, lower esophageal sphincter pressure and esophageal body amplitude were decreased and the risk of ineffective esophageal motility was increased. Total and recumbent acid exposure times were increased. After RYGB, an increased risk of ineffective esophageal motility was observed. Total, upright, and recumbent acid exposure times were decreased. The total reflux episodes remained unchanged but with increased nonacid reflux and decreased acid reflux events. Including our largest series, 31 EAC cases have been reported to date after SG and RYGB. DISCUSSION: This systematic review demonstrates increased acid reflux after SG and decreased acid reflux after RYGB. An observed increased nonacid reflux after RYGB might contribute to failure of gastroesophageal reflux disease improvement. This refluxate might be noxious to the esophagus, warranting further studies. RYGB might not entirely preserve esophageal function as previously believed.