New model of colon interposition following distal gastrectomy in rats.

An interposed colon segment has been clinically used as a gastric substitute following an esophagogastric resection for benign or malignant esophageal and gastric cardia disease. The purpose of this study is to establish a rat model of colonic interposition following distal gastrectomy and to investigate its serial mucosal changes. About 80% of the glandular stomach was resected, and a 3-cm segment of the transverse colon interposed isoperistaltically between the remnant stomach and duodenum. Epithelial proliferation and aberrant crypt foci in the interposed colon segment were investigated serially. Crypt lengths in the interposed colon increased significantly (P < 0.05) compared to the remnant colon. The number of goblet cells per crypt per 1 mm in the interposed colon also decreased significantly (P < 0.05) compared to the remnant colon. A PCNA labeling index (LI) of the remnant colon was almost 30%. A PCNA LI in the interposed colon at 4, 8, and 12 months after surgery was 30.8%, 31.8%, and 47.8%, respectively. The PCNA LI in the interposed colon increased significantly (P < 0.05) 12 months after surgery compared to the remnant colon at 4, 8, and 12 months after surgery. Aberrant crypt foci were not detected in the interposed colon segment. In conclusion, we established a rat model of colonic interposition following distal gastrectomy. The interposed colon mucosa adapted well. Long-term mucosal changes of the interposed colon segment should now be studied.