Reflux after bariatric surgery and the role of preoperative endoscopy

Obesity is a vastly growing global health concern. In 2014, 39% of the adult population in the world was overweight or obese. Bariatric surgery is the most efficient means of obesity management. The most commonly performed operations in the world are Sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB). Excellent weigh-loss results and remission of comorbidities have been reported for all bariatric techniques. Distinct adverse effects are, however, typical to each technique. SG has been shown to cause gastro-esophageal reflux disease (GERD). OAGB has been suspected to cause a potentially cancerogenic form of GERD (bile reflux). Objective evidence of increased bile reflux after OAGB is, however, lacking. A scintigraphic method for detecting postoperative bile reflux after OAGB has not been applied in previous studies. A gastric bypass operation entails a risk of leaving a significant lesion in the excluded portion of the stomach or duodenum. Pre- and postoperative endoscopies are reliable methods for investigating the upper gastrointestinal tract for significant lesions and for detecting signs of GERD. There is no clear consensus on whether a preoperative esophago-gastro-duodenoscopy (EGDS) should be done routinely prior to bariatric surgery and how frequently significant findings are detected This thesis aims at finding out how often significant findings are detected in preoperative EGDS and evaluating whether preoperative EGDS should be routinely done for all patients prior to bariatric surgery. This thesis also aims at finding out whether a scintigraphic method is feasible for detecting bile reflux and to what extent bile reflux is found after OAGB. In Study I, 13 consecutive OAGB patients were invited to undergo a bile reflux scintigraphy and postoperative upper gastrointestinal endoscopy (UGE) at mean 10.7 months after OAGB. In Study II, findings of all (n=1275) preoperative EGDSs prior to all bariatric operations during a 9.5-year period are reported. All reoperations after SG for the same period are studied in the same cohort. Study III is a part of an open-label randomised controlled clinical trial comparing RYGB and OAGB (RYSA trial). In Study III, 40 patients underwent preoperative EGDS prior to OAGB. A bile reflux scintigraphy and a postoperative UGE were studied six months after OAGB. In Study II, significant finding regarding SG was detected in 23.0% of patients and in 1.6% regarding gastric bypass in a preoperative EGDS. Reflux symptoms were reported for 49.0% of patients with a significant EGDS finding. During the follow-up of Study II, 26 SG patients required a reoperation, half of them due to GERD. Scintigraphy verified bile reflux into the gastric pouch after OAGB was found in 55.5% and 31.6% of patients in Studies I and III, respectively. One patient also had bile reflux activity in the esophagus in Study III. Postoperative UGE after OAGB revealed lesions suggestive of GERD in 39.5% patients in study III. Significant findings in asymptomatic patients regarding SG are often encountered in preoperative EGDS, but significant findings regarding gastric bypass are quite rarely found. Based on this evidence, preoperative EGDS should be done for all patients prior to SG and for patients with a known risk for gastric pathology prior to gastric bypass. Bile reflux scintigraphy is a reliable tool for detecting bile reflux after OAGB. Roughly one-third of patients had GERD lesions in endoscopy and bile reflux in scintigraphy after OAGB.