The purpose of this study was to evaluate whether bacterial biofilms exist on the sinus mucosa surfaces of human subjects with recalcitrant chronic sinusitis. Scanning electron microscopy was used to evaluate patients with continued symptoms of chronic sinusitis despite prior appropriate medical and surgical management. Morphologic structures that confirm the presence of bacterial biofilms were identified on the sinus mucosa of patients infected with Pseudomonas aeruginosa, a known biofilm former. The presence of bacterial biofilms may explain the recalcitrant nature of some forms of chronic sinusitis.

Objectives/Hypothesis: To study the effects of bone involvement in experimentally induced sinusitis and the effect of involved bone on the overlying mucosa. Study Design: Animal study. Methods: Sinusitis was induced unilaterally with Pseudomonas aeruginosa in the maxillary sinus of 19 New Zealand white rabbits. At 6 weeks, the pathogenic organism was confirmed by culture, and a segment of the bone from the medial wall of the sinus implanted in a submucosal pocket in the opposite sinus. The rabbits were killed at predetermined time intervals up to 13 weeks from sinusitis induction, and en bloc sinus sections were decalcified and stained. Results: The implanted bone reabsorbed partially or totally in all specimens. However, the study revealed clear histological evidence of bone involvement adjacent to the infected sinuses and the bony changes extended to the noninfected side in all specimens. The histological findings were identical to those seen in chronic osteomyelitis. Conclusions: This study demonstrates the ability for pseudomonal sinusitis, at least in the presence of surgical intervention, to involve bone at a distance from the site of primary infection in the absence of intervening mucosal disease. If confirmed with additional organisms and models, these findings have significant implications for the therapeutic management of chronic sinus disease.

The study provides further evidence that bacterial rhinosinusitis can involve bone at a distance from the site of primary infection, thereby suggesting that infectious agents may spread through bony structures in the pathogenesis of chronic rhinosinusitis.

This is evidence of the possible presence of bacterial biofilms on frontal sinus stents in patients with chronic sinusitis. Further study into the role of bacterial biofilms in perpetuating chronic sinusitis is warranted.

This is evidence of the presence of bacterial biofilms in an animal model of sinusitis. This model may serve as a means to study the efficacy and safety of pharmacologic and surgical treatments on the disruption and elimination of bacterial biofilms. Additional study into the role of bacterial biofilms in perpetuating chronic sinusitis is warranted.