Restoration of the mucociliary clearance of the maxillary sinus after endoscopic sinus surgery

Background: Whether endoscopic sinus surgery (ESS) restores the mucociliary clearance of the maxillary sinus needs further evaluation. Methods: We evaluated the mucociliary clearance of the maxillary sinus by using a radionuclide technique in 12 patients with chronic sinusitis (sinusitis group) and in six patients who had undergone ESS 6 to 14 months after the surgery (post-ESS group). The mucosal cilia taken from the maxillary sinus in 12 patients with sinusitis before and after ESS (paired experiments) were examined by light and electron microscopy. Results: The radionuclide placed endoscopically in the maxillary sinus in eight patients immediately after ESS maintained 81.2% ± 16.3% of its radioactivity after 30 minutes. This result was consistent with results in four patients with untreated chronic sinusitis in whom the radionuclide had been instilled by antral puncture (86.9% ± 3.5%). On the other hand, in six patients in the post-ESS group the radionucleotide maintained only 25.9% ± 11.6% of its radioactivity, demonstrating statistically significant differences from those of both the sinusitis group without ESS (p < 0.005) and the group 4 days after ESS (p < 0.005). The absence of the cilia in the sinusitis condition was recognized in 35.5% ± 12.1% (n = 12) of the epithelial cells. On the other hand, the absence of cilia was significantly (p < 0.01) reduced to 5.3% ± 3.7% of the epithelial cells in the post-ESS condition. Electron microscopic observation also revealed abnormal cilia in the sinusitis condition, whereas the mucosal cilia were regularly arranged in the post-ESS condition. Conclusions: The mucociliary clearance of the maxillary sinus disturbed by chronic inflammation was restored by ESS, indicating the clinical effectiveness of ESS for the treatment of chronic sinusitis.