Tracheal Stenosis Induction: A Comparison of Open Versus Endoscopic Methods in a Rabbit Model

EDUCATIONAL OBJECTIVE At the conclusion of this presentation, the participants should be able to appreciate the value of an endoscopic method of inducing tracheal stenosis in a rabbit model. OBJECTIVE Compare the induction of tracheal stenosis by an endoscopic versus an open method. STUDY DESIGN Prospective animal study. METHODS Fifteen adult male New Zealand White rabbits underwent induction of tracheal stenosis. Six animals received mucosal injury directly through a tracheotomy and 10 strokes of a nylon brush. Nine animals received tracheal injury endoscopically: a rigid bronchoscope was placed a measured distance below the inferior edge of the cricoid cartilage and a nylon brush was passed 4 times in each of the 4 quadrants. Endoscopies were performed 3 weeks after injury. Stenosis was measured as a percentage of luminal narrowing by a consensus of 3 individuals viewing the procedure on a television monitor. RESULTS Only 1 animal in the tracheotomy group had noticeable stenosis (40%). In the endoscopic group, all animals had some degree of stenosis, ranging from 10-80% (mean 40%). The mortality rate was 20% (3/15). In the tracheotomy group, 1 mortality occurred secondary to antibiotic-induced gastroenteritis. In the endoscopic group, 2 mortalities occurred in the immediate postoperative period secondary to laryngeal edema. These 2 animals were the first to undergo the procedure, which lasted approximately 30 minutes. After refining our technique, succeeding procedures lasted an average of 5 minutes and there were no mortalities. The average duration of the tracheotomy procedure was 45 minutes. CONCLUSIONS Using an endoscopic method can greatly improve the induction of tracheal stenosis by reducing operative time and eliminating an open wound and the need for antibiotics. It also achieves stenosis more consistently than an open technique.