Biofilm and persistent inflammation in endoscopic sinus surgery.

Bacterial biofilms have been observed in many patients with chronic rhinosinusitis, but their importance is still being investigated. This study examines the association between biofilms and other clinical findings in chronic rhinosinusitis patients. Twenty-four patients with chronic rhinosinusitis who failed medical management underwent endoscopic sinus surgery (ESS). Tissue was collected from the ethmoid sinus and analyzed for the presence of biofilm by hematoxylin and eosin staining, fluorescent in situ hybridization, and confocal scanning laser microscopy. Biofilms were classified as extensive (> 50% of mucosal surface in sample) or present (< 50% of surface). The surgeon remained blinded to the biofilm status of patients until postoperative follow-up was complete. The presence of bacterial biofilm was strongly associated with persistent mucosal inflammation after ESS (53% of biofilm-positive patients vs 0% of biofilm-negative patients, P = 0.009). The amount of biofilm was not important as there was no significant difference between the extensive and present biofilm classifications with respect to inflammation. The presence of biofilm was not associated with prior ESS, allergies, eosinophils, polyps, or presence of fungal elements.