Development of a survival animal model for subglottic stenosis

Objective: To develop a reproducible survival animal model for subglottic stenosis.

Study design: Prospective study.

Methods: We evaluated five methods of inducing airway injury in 30 New Zealand white rabbits to produce a subglottic stenosis model. Experimental groups comprised: group 1 (n = 5), which underwent 4-hour intubation; group 2 (n = 5), which underwent induced subglottic injury with a nylon brush; group 3 (n = 10), which underwent subglottic injury with a nylon brush, followed by 4-hour intubation; group 4 (n = 5), which underwent subglottic injury with Bugbee cautery in 50% of the subglottic circumference, followed by 4-hour intubation; and group 5 (n = 5), which underwent subglottic injury with Bugbee cautery in 75% of the subglottic circumference, followed by 4-hour intubation. Five animals were used as controls. Endoscopy of the airway and sacrifice of animals were planned at an interval of 14 days postinjury. Histologic measurements were analyzed.

Results: No animals in groups 1 or 2 developed stenosis. In group 3, 50% of animals developed symptomatic grade 3 subglottic and tracheal stenosis, necessitating early endoscopy and sacrifice in three animals. Four animals in group 4 developed grade 1 subglottic stenosis, and four in group 5 developed grade 2 subglottic stenosis. Histologic measurements of lumen areas within each of these two groups were similar; all animals survived the follow-up period.

Conclusion: We successfully developed a reproducible survival model for induced subglottic stenosis using a combination of cautery-induced subglottic injury followed by 4-hour intubation. This model lays the foundation for future studies that evaluate endoscopic interventions for the management of subglottic stenosis.

Level of evidence: NA Laryngoscope, 129:989-994, 2019.