ObjectiveTo establish a simple and stable model of benign tracheal stenosis in SD rats by nylon brush scraping induced mechanical injury, and to observe the pathological changes of tracheal tissue at different time points after modeling.MethodsTwenty SD rats were divided into sham operation group (10 rats) and stenosis model group (10 rats) by random number method. Symptoms and survival conditions were observed, tracheal tissues were obtained, granulation tissue proliferation was observed, and stenosis indexes were measured and compared. Another fifteen rats were sacrificed at different time points (days 0, 2, 4, 6, and 8) after modeling. Tracheal tissues were obtained, HE staining and Masson staining were performed to observe pathological changes with time.ResultsThe survival rate of the sham operation group was 100% on the 8th day after operation, and the survival rate was 0% on the 8th day after operation in the stenosis model group. The difference in survival condition between the two groups was statistically significant (P=0.000 1) by Log-rank test. The stenosis index in the sham operation group was (6.12±1.78)%, and in the stenosis model group was (60.28±12.56)%. The difference in the stenosis between the two groups was statistically significant (P<0.000 01). HE staining results showed that the tracheal lumen was unobstructed and no granulation tissue hyperplasia or stenosis was found in the sham operation group. The epithelial mucosa was intact and smooth, and the cilia structure was clearly visible. It was a pseudo-stratified ciliated columnar epithelium, which was consistent with the characteristics of normal airway mucosa. While in stenosis model group, the lumen was significantly narrowed, and the stenosis was mainly caused by granulation tissue hyperplasia. No epithelial structure was observed, or epithelial structure was extremely abnormal. Masson staining showed that the fibroblasts in the injured site increased first and then decreased, and the collagenous fiber (blue) in the injured site gradually increased with time.ConclusionsA model of benign tracheal stenosis in rats can be successfully established by nylon brush scraping induced mechanical injury. The modeling method is simple, controllable and reproducible. The model can be widely used in the investigation of pathogenic mechanism for benign airway stenosis and efficacy exploration of new treatment.