The association between sleeve gastrectomy and histopathologic changes consistent with esophagitis in a rodent model

Background: As the association between sleeve gastrectomy (SG) and gastroesophageal reflux disease remains unclear, the aim of this study was to evaluate whether performance of SG impacts the development and severity of esophagitis in a rodent model. Setting: University Hospital. Methods: Wistar rats (Charles River Institute, Wilmington, MA) were fed a high fat diet (HFD) for 4 months and then were divided into 3 cohorts of nearly equal mean weight: HFD only (n = 25), sham operation + HFD (n = 29), and SG + HFD (n = 19). Animals were euthanized at 12 weeks. The esophagus was harvested en-bloc and processed for histologic assessment by a board certified pathologist, blinded to the animal treatment group. Reflux was graded by severity and defined as the presence of inflammation in the esophageal squamous mucosa. Results: Rats who underwent SG had significantly increased reflux severity, compared with sham and HFD alone (21.1% versus 0% versus 4.5%, P = .02), respectively. No difference was demonstrated in negative, mild, or moderate esophagitis between the control, sham, and sleeve groups. Using nonparametric ANOVA, the mean severity score for severe esophagitis was significantly increased in the SG group versus sham or HFD group (1.5 versus .81 versus 1.36, P = .0202) respectively. Following multinomial logistic regression to assess for confounding variables to the severity scores, final weight, and change in weight, had no effect on severity of esophagitis between the 3 groups (P > .373). Conclusions: SG is independently associated with histopathologic changes consistent with severe esophagitis in an animal model, likely secondary to gastroesophageal reflux. (C) 2015 American Society for Metabolic and Bariatric Surgery. All rights reserved.