Endoscopic evaluation of esophago-gastro-jejunostomy in rat model of Barrett's esophagus

Abstract

Background and aims Endoscopy can be used to monitor the onset of metaplastic transformation and to observe the progression of neoplasia in small animal models of Barrett’s esophagus. By avoiding animal sacrifice, the natural history of this disease can be studied in a longitudinal fashion. We aim to characterize the endoscopic features of esophageal mucosa at various stages of the metaplasia-dysplasia-carcinoma sequence in a rat reflux model of Barrett’s for comparison with histology. Methods Acid and bile reflux was produced by introducing a side-to-side esophago-gastro-jejunostomy in Sprague-Dawley rats. Endoscopic examination of the distal esophagus was performed in 24 surgically-altered and 4 control rats, between weeks 24 to 36 after the operation in 4 week intervals, and all rats were biopsied and sacrificed at 36 weeks. Endoscopic images were classified based on the surface mucosal patterns of the distal esophagus and then compared to histology. The endoscopic appearance were classified as: 1) normal, characterized by a smooth surface; 2) intestinal metaplasia, defined as elevated plaques/ridges, deep grooves and thin linear folds; 3) dysplasia, indicated by coarse folds/grooves, mesh-like villi, and foveolar appearance, and 4) carcinoma, suggested by irregular shaped mass lesions with ulcerations. Results The endoscopic criteria for intestinal metaplasia yielded a sensitivity of 100% in comparison to histology. Intestinal metaplasia with high-grade dysplasia was found in 2 rats and with low-grade dysplasia in 3 rats. Both focally-invasive squamous cell carcinoma and invasive adenocarcinoma were found in 1 rat. Conclusions Small animal endoscopy in a rat model of Barrett’s esophagus can be used to perform surveillance, classify mucosal patterns, observe the onset of intestinal metaplasia, and monitor the progression of neoplastic transformation, representing a useful tool for studying the natural history of this disease.

Side to Side Esophagogastrojejunoplasty in Post-corrosive Stricture of Distal Esophagus and Proximal Stomach

“…Alkaline reflux is highly improbable due to the long Roux jejunal loop, and isolated gastric juices are less likely to be responsible for causing any change of the esophageal mucosa. For development of Barrett's esophagus, exposure of both gastric juices and bile acids is required for long duration of about 40-50 years [3,4].…”

Detection of fluorescent organic nanoparticles by confocal laser endomicroscopy in a rat model of Barrett’s esophageal adenocarcinoma

“…32 The animals were given 5 mg/kg of tramadol (Contramal ® , Formenti, Verona, Italy) intraperitoneally immediately after the peritoneal incision. At the end of the surgical procedure, the animal was roused, maintaining 1 L/min oxygen.…”

Establishing Magnetic Resonance Imaging as an Accurate and Reliable Tool to Diagnose and Monitor Esophageal Cancer in a Rat Model

“…Visual endoscopic analysis has been utilized as a tool for monitoring the natural history of disease [15], with biopsy allowing for analysis of molecular markers while avoiding animal sacrifice [16]–[18]; however, due to the inherent model limitation of the extra-luminal presentation of the majority of tumors, as well as the low accuracy of endoscopic biopsies, adenocarcinoma histology has only been validated post-mortem [15].…”