Bacterial colonization of airway stents: a promoter of granulation tissue formation following laryngotracheal reconstruction.

OBJECTIVE To investigate whether airway granulation, a common occurrence during laryngotracheal reconstructive surgery and a common cause of delays in definitive treatment and treatment failure, is associated with a microbial etiology. DESIGN Prospective case-control study. SETTING Tertiary referral airway reconstruction unit. PATIENTS Patients who had an airway stent as part of their treatment for laryngotracheal stenosis. INTERVENTIONS All airway stents were sent for microbiological analysis. Information about patient demographics, lesion characteristics, and presence of airway granulation tissue at different times during treatment were obtained and correlated against the microbiological findings from airway stents. MAIN OUTCOME MEASURES A chi2 test was used to correlate airway colonization with specific pathogens and occurrence of airway granulation. Logistic regression analysis was used to identify independent microbiological predictors of airway granulation. RESULTS Thirty-one airway stents were removed from 26 patients. The mean (SD) age at presentation was 42 (18) years, and postintubation tracheal stenosis was the most common etiology. There were highly significant associations between stent colonization with Staphylococcus aureus and Pseudomonas aeruginosa and the occurrence of airway granulation (P<.02), and these microorganisms were independently associated with the risk of developing airway granulation. Furthermore, S aureus was associated with persistence of airway granulation on average 4 months following removal of the stent. CONCLUSIONS Airway granulation seems to be associated not with polymicrobial airway colonization but with infection with specific pathogenic microorganisms. All patients undergoing laryngotracheoplasty should receive antibiotic prophylaxis to cover these microorganisms, and the development and use of antibiotic-impregnated airway stents should be explored.