Deposition of aerosolized particles in the maxillary sinuses before and after endoscopic sinus surgery

Background: Recent studies suggest that topical therapy is beneficial in many conditions underlying chronic sinusitis. Current literature has documented low aerosolized particle deposition efficiency into the paranasal sinuses. Mathematical modeling suggests that three factors influence the deposition efficiency: particle size, pressure gradient, and size of the sinus ostium. Ostium size is the most dominant factor. Therefore, we sought to determine if maxillary antrostomy and ethmoidectomy would increase the deposition efficiency. Methods: Five cadavers underwent pre- and postoperative scintigraphy after administration of aerosolized Tc-99M. Images were obtained with a γ-camera and regions of interest (ROIs) were drawn around the maxillary sinuses. Counts per minute in the pre- and postoperative ROIs were then compared using the paired t-test. Results: Results indicated a significant increase in deposition of radioactivity in the maxillary sinuses in the postoperative state (p < 0.01). Conclusion: Topical therapy for chronic sinusitis may be more feasible in the postoperative population.