The role of bone in chronic rhinosinusitis

Objectives. To evaluate and confirm the histological inflammatory changes that occur in bone and in the overlying mucosa in experimentally induced chronic rhinosinusitis and to evaluate differences in the inflammatory patterns that may occur with different organisms. Study Design: Histological study of induced maxillary rhinosinusitis in 29 New Zealand White rabbits (15 with Pseudomonas aeruginosa, 14 with Staphylococcus aureus) 7 to 9 weeks after infection. Methods: Following maxillary sinus ostial infection, unilateral chronic bacterial rhinosinusitis was induced in 29 New Zealand White Rabbits, using Pseudomonas aeruginosa (n = 15) and Staphylococcus aureus (n = 14). The pathogenic organism was confirmed by culture, and the rabbits were sacrificed at predetermined time intervals (7,8, and 9 wk) from the time of infection. Following harvest, en bloc sinus sections were mounted, stained, and analyzed. Specific attention was given to identifying histological changes in paranasal sinus bones on both sides. Results. All animals (29 of 29) demonstrated histological evidence of operative occlusion on the side of the original inoculum, and all were culture-positive for the inoculated organism at death. Histological evidence of chronic rhinosinusitis in the inoculated sinus was demonstrated in 86% of animals (25 of 29). Evidence of chronic osteomyelitis in the noninfected side was seen in 15 of 29 animals (52%) overall, or 9 of 15 animals (60%) infected with pseudomonas and 6 of 14 (43%) animals infected with staphylococcus organisms. Conclusions. 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.