Mucociliary Clearance in Experimental Chronic Sinusitis

Abstract

Abnormal mucociliary clearance in the paranasal sinuses is a significant factor in the pathogenesis of sinusitis. This study examined effects of chronic sinusitis on ciliary beat frequency (CBF), mucociliary transport (MCT) velocity, mucociliary transport patterns, and histology of sinus mucosa in rabbits. Two groups of rabbits were studied: uninfected (n = 9) and infected (n = 18). Maxillary sinus ostia in all animals were occluded, and sinuses in the infected group were inoculated with 108 cfu of Streptococcus pneumoniae. Chronic sinusitis developed over 6 weeks and was confirmed by histopathology and culture. Evaluation of the MCT mechanism included 1) measurement of CBF using a photometric technique, 2) direct measurement of MCT velocity, and 3) analysis of MCT patterns with inert India ink. In seven of nine (77.8%) uninfected animals, the mean CBF was 11.5 Hz (±.39 Hz) initially and 11.3 Hz (±.32 Hz) 6 weeks after occlusion (P = 0.69). MCT velocity measured 20.6 mm/min (±1.40 mm/min) initially and 16.85 mm/min (±1.96 mm/min) 6 weeks after occlusion (P = 0.16). In the infected group, there were statistically significant decreases in CBF (P < 0.05) and measured MCT velocity (P < 0.05). Examination of MCT in infected animals showed patterns of misdirected flow, pooling, and stagnation. Histopathologic changes included significant losses of ciliated epithelium and mucosal abnormalities consistent with chronic sinusitis. Chronic sinusitis secondary to long-standing bacterial infection leads to alterations in CBF, MCT velocity, and MCT patterns in the paranasal sinuses of rabbits.