Comparative Evaluation of Mechanical Injury Methods for Establishing Stable Tracheal Stenosis Animal Models

Abstract

Abstract To compare the stability of different mechanical injury methods for establishing tracheal stenosis animal models with endoscopic assistance and explore the feasibility of tracheal stoma in the establishment of tracheal stenosis animal models.Twenty-one healthy adult New Zealand white rabbits were randomly divided into an experimental group and a control group. In the experimental group, eight rabbits underwent tracheal incision followed by steel brush scraping with endoscopic assistance. In the control group, nylon brush scraping was performed. The control group was further divided into two subgroups (Group A and Group B). Group A consisted of eight rabbits undergoing scraping without tracheal stoma, while Group B included five rabbits undergoing scraping followed by tracheal stoma. All experimental rabbits were observed under endoscopy for tracheal stenosis changes at 7 days, 14 days, and 21 days after scraping. On the 21st day, the rabbits were euthanized, and histological observations were conducted after HE staining of the specimens.All 16 rabbits in the group without tracheal stoma survived well. The experimental group showed significant stenosis compared to Group A of the control group (P<0.05). All rabbits in Group B of the control group died at different time points after the operation. HE and Masson staining of the narrowed tracheal specimens revealed a small amount of inflammatory cell infiltration in the submucosa, along with fibroblast proliferation and abundant deposition of collagen fibers.Compared to nylon brush scraping, steel brush scraping with endoscopic assistance is a more effective method for mechanically inducing stable and pronounced tracheal stenosis in animal models. However, the survival of experimental rabbits undergoing tracheal fistula remains challenging and requires further exploration.