PURPOSE: Airway stents are specially designed prosthetics used to relieve intramural, extramural and transmural airway obstruction. Stents increasingly are being used, in advanced bronchoscopic techniques to treat airway disorders, e.g. tracheobronchial disorders caused by malignant or benign tumors, extrinsic compression, post-intubation tracheal injuries, tracheobronchomalacia, or sequelae after tracheostomy. There are two main types of airway stents (hybrids of both are also available) currently available; tube stents made of silicone, and expandable metallic stents.The lower airways are usually sterile despite exposure to significant amount of pathogenic organisms from both the external world and secretions. We seek to evaluate the microbiologic changes that occur in the airways after placement of airway stents, for treatment of various airway disorders.
METHODS: Retrospective review of 42 patients (17males, 24 females) with stents placed for various indications followed for a period of 1-2years (2004-2006), with interval bronchoscopies and BAL, bronchial wash specimen, and sputum microbiology for various indications. Cultures, colony counts, with presence or absence of PMN were determined.
RESULTS: The most common indication for bronchoscopy after stent placement was stent check 60%, followed by evidence of/or suspicion of infection 18%, others include stent displacement/migration 12%, Obstruction 8%, and hemoptysis <1%. In almost 80% of samples organisms Isolated were Polymicrobials with gram positive organisms predominating (61% of samples), the most common Isolates with colony counts > 102 were staphylococcus spp., 39% others were streptococcus spp. 17%, Micrococcus spp 4% Corynbacteria spp 20%, Pseudomonas spp 14%, and Neiserria spp 5%.
CONCLUSION: The predominant organisms isolated from the airway after stent placement are gram positives, and in about 80% of cases multiple organisms are isolated. Most patients are asymptomatic (Colonization), in only about 18% of cases was there a concern for infection requiring antibiotics. Although isolated organisms sometimes have significant colony counts they are non pathogenic in most instance.
CLINICAL IMPLICATIONS: Airway stent placements results in polymicrobial colonization of the airways in most cases, and it is associated with true lower airway infection in about 18% of cases.
DISCLOSURE: Razaq Badamosi, None.