Reversibility of Abnormal Mucociliary Clearance in Experimental Chronic Sinusitis

Abstract

Normal mucociliary clearance in the paranasal sinuses must be restored to reverse the effects of chronic sinusitis. This study examined effects of middle meatal antrostomy (MMA) on ciliary beat frequency (CBF), mucociliary transport (MCT) velocity, MCT patterns, and histology of sinus mucosa in rabbits with chronic sinusitis to determine whether objective measures of mucociliary function and histology could be reversed. Two groups of rabbits were compared: uninfected (Group A controls, n = 9) and infected (Group B, n = 11). Maxillary sinus ostia were occluded; 108 cfu of Streptococcus pneumoniae were inoculated into sinuses of rabbits in group B, and chronic sinusitis developed. This was confirmed by histopathology and culture 6 weeks after infection. Middle meatal antrostomies were performed in the infected group, and sinuses were studied 6 weeks later. Control animals (Group A) had mean CBF = 11.5 Hz (±.39 Hz). Animals with chronic sinusitis (Group B) had mean CBF = 8.6 Hz (±.24 Hz). This was statistically different from control (P < 0.05). Six weeks following MMA, group B had mean CBF = 12.9 Hz (±.75 Hz). This was not different from control. There were changes in MCT velocity that correlated with the CBF (r = 0.72). Examination of MCT patterns after MMA demonstrated minimal pooling and stagnation; however, small areas of misdirected flow persisted. After MMA, there were decreased numbers of inflammatory and goblet cells and increased numbers of ciliated epithelial cells. This study demonstrated that mucociliary clearance and histological changes seen in rabbits with chronic sinusitis are reversed by MMA.