The role of infection in the pathogenesis of acquired tracheal stenosis.

A rabbit model was developed to study the role of infection in the development of postintubation acquired subglottic and tracheal stenosis. Following a surgically induced tracheal mucosal injury, rabbits were divided into three groups. Five animals underwent intratracheal bacterial inoculation using Staphylococcus aureus, six rabbits were given prophylactic antibiotics, and five control animals received neither bacteria nor antibiotics. After 10 days the rabbits were assessed for both tracheal stenosis and bacterial infection within the respiratory tree. Animals receiving antibiotic prophylaxis had a mean stenosis of 50.8%, similar to the 63.4% observed in controls. Rabbits inoculated with SA had a mean stenosis of 85.0%, greater than both the other groups (P = .001:ANOVA). Considering all animals, those with respiratory infection (including two control rabbits) had narrower stenoses than those that remained noninfected (82.1% versus 52.5%; P = .001). These data suggest that bacterial infection in the upper respiratory tract might increase the severity of airway stenosis following prolonged endotracheal intubation.