Bacterial colonization of central airways after stenting

Airway stenting (AS) is increasingly used in the management of obstructive lesions of the central airways. Although retention of secretions and infect ion have been reported as complications of AS, the microbiological conseque nces of AS have not yet been evaluated. In this study, we prospectively per formed protected specimen brush (PSB) sampling of the airways, before and 3 to 4 wk after AS, in 14 consecutive patients (65 +/- 17 yr), suffering fro m bronchial (5), extensive esophageal (2), thyroid (1), and adenocystic (1) carcinoma, stenotic tracheal burn lesions (2), postintubation stenosis (2) , and Wegener's granulomatosis (1). A cutoff value of greater than or equal to 10(2) colony-forming units (cfu) . ml(-1) was considered diagnostic for airway colonization (AC). PSB results were related to the presence and deg ree of secretion retention (SR) at the level of the stent. In five of the 1 4 patients, AC was present prior to AS; in three of these, potentially path ogenic microorganisms (PPM) were identified. After AS, AC was found in 11 ( including seven patients without prior AC) of the 14 patients. In six of th ese patients, one or more PPM were present (Pseudomonos aeruginosa [4], Sta phylococcus aureus [3], Streptococcus pneumoniae [1], Klebsiella spp. [1]). Although AC tended to be associated with the presence of SR (PSB greater t han or equal to 10(2) cfu . ml(-1) in 10 of 12 SR-positive and in zero SR-n egative cases; PSB < 10(2) cfu . ml(-1) in two SR-positive and in two SR-ne gative cases), statistical significance was not reached (Fisher exact test, p = 0.06). We conclude that AS is frequently followed by AC, the majority of which occurs in patients without AC prior to AS, and is caused by PPM. I n no case, however, AC was associated with clinical signs of infection. AC tended to be associated with SR in the stent.