Porcine model of airway mucosal injury

The development of a reliable animal model of laryngeal or tracheal stenosis has been limited by lack of reproducibility, high morbidity and mortality, and cumbersome technique. The small size of previously proposed models has limited the development of innovative reconstructive techniques.

Eleven of 15 post-weanling commercial piglets underwent injury by a sharpened metal rod to the anterior half of the subglottic region at repeated intervals under endoscopic guidance. Four of 15 animals did not undergo injury and served as control for normal subglottic growth over time. Each airway was sized by endotracheal tube (ETT) passage and endoscopic photography over time, and the degree of total stenosis was estimated in comparison to the control animals.

The first two animals underwent daily injury and expired from copious granulation tissue. Eight additional animals developed symptomatic subglottic stenosis manifested by audible stridor and intercostal retractions while undergoing injury every third day. Photographs documented the size of the stenosis to be greater than 50% (40% by ETT sizing) with a mean of three injuries in a mean time of 18 days.

The porcine model shows a high degree of tolerance with minimal morbidity and consistent reliable results in an animal model of airway stenosis that is suitable for further innovative studies.