食管良性狭窄动物模型的建立及病理学分析

Reproduction of a new canine model of benign esophageal stenosis and pathological observation

目的通过胃镜下烧灼的方法建立犬食管良性狭窄模型并观察建模不同时间后的局部形态学变化。方法健康成年犬8只，麻醉后放置食管套管，胃镜下用电热活检钳（混合电流40J／s）环形烧灼距门齿32～35cm处食管，每周复查胃镜观察食管狭窄情况及黏膜变化，并钳取组织进行病理分析。术后1、2、4、8周分批处死动物，取出狭窄部位食管组织进行病理分析。结果术后1周食管黏膜充血水肿明显，溃疡形成，可见食管狭窄、局部黏膜坏死及大量炎性细胞浸润；术后2周食管黏膜充血水肿减退，食管狭窄明显，食管组织增生显著，局部有广泛肉芽组织形成及部分纤维化，炎细胞浸润明显；术后4周及8周食管狭窄达0．4～0．6cm，局部形成白色瘢痕，出现大量的纤维结缔组织，炎细胞及新生毛细血管显著减少。结论通过局部烧灼的方法可以建立稳定的犬食管良性狭窄模型，其病理表现主要为肉芽组织形成及纤维化。

Objective To reproduce a new canine model of benign esophageal stenosis and to observe its pathological changes at different periods. Methods The esophargus wall 32～35cm from the incisor was cauterized circumferentially with a electric current of 40J/s through an endoscope. 8 adult dogs were used. The morphological changes were examined endoscopically and microscopically at the end of 1st, 2nd, 4th and 8th week. Results At the end of one week, the Narrowing of the lumen was detected at the end of the 1st week. The mucosa became highly congested and swollen, with neerosis of tissue and infiltration of inflammatory cells. At the end of two weeks, the narrowing was getting worse, and granulation and fibrous tissue appeared in the submucosa with marked cellular infiltration. At the end of four and eight weeks, the narrowing was stable with a diameter of 0.4-0.6cm, and excessive granulation tissue and proliferation of fibrous tissues with reduction of inflammatory reaction were detected in the whole-hickness of the esophageal wall. Conclusion An animal model of benign esophageal stenosis as a result of cauterization is reliable, and it is characterized by inflammatory response, which is replaced gradually by granulation tissue and fibrosis.