Histologic and endoscopic studies before and after gastric bypass surgery.

The purposes of this study were to establish a standardized multiparameter analysis system for histologic grading of gastritis and to compare histologic changes with endoscopic findings in the proximal and distal bypassed stomach in obese patients undergoing gastric bypass surgery. Three groups, comprising a total of 91 patients, were studied: a preoperative group (34 patients), a postoperative group at one year (33 patients), and a postoperative group at two years (24 patients). the biopsy specimens from the proximal and distal bypassed stomach were compared in all groups. Seventeen histologic variables were evaluated by three observers to classify the severity of gastritis. Forty percent of the patients in the postoperative group demonstrated histologic evidence of nonerosive, superficial gastritis, slightly more in the proximal stomach. Endoscopy showed significantly more bile reflux and inflammation in the distal stomach than the proximal stomach in nearly all patients. Our study demonstrates a significant discrepancy between bile reflux observed endoscopically and the histologic findings after gastric bypass surgery. No metaplastic or dysplastic changes were found up to two years postoperatively, but further studies are needed to determine the long-term endoscopic and histologic endoscopic and histologic sequelae of gastric bypass surgery.