A Rat Model of Esophagogastric Anastomotic Stricture

Esophagogastric anastomosis stricture is one of the most common postoperative complications after esophagectomy; yet, its pathogenesis is still not fully understood, and the treatment and prevention of anastomotic stricture are limited due to the lack of a proper animal model. The insufficient blood supply in the gastric tube is considered a risk factor for postoperative anastomotic strictures. In this study, we used thermal imaging to develop a stable rodent model with esophagogastric anastomotic stricture caused by ischemia. Briefly, 30 male Sprague-Dawley rats have been divided into the control group and the ischemia group. The esophagogastric ischemia anastomosis was performed with the help of intraoperative thermal imaging to identify the poor perfusion area. An unpaired t test with Welch's correction was used to analyze the difference between the two groups. On postoperative day 84, in the control group, no anastomosis stricture was observed, while in the ischemia group, 12 out of 15 animals (80%) developed obvious anastomosis stricture which could not let a 2.7-mm endoscope pass through. The diameter of the anastomosis in the control group and the ischemia group were 2.80 ± 0.15 mm and 1.73 ± 0.44 mm (p < 0.01), respectively (evaluated by endoscopy examination and barium radiography). H&E stain and Masson's trichrome showed that the anastomosis in the ischemia group had more connective tissue hyperplasia and collagen deposition than control group. Thus, this new rat model can be used as a platform to further investigate the potential interventions for prevention of esophagogastric anastomotic stricture.