Micro and nanoparticle deposition in human nasal passage pre and post virtual maxillary sinus endoscopic surgery

Realistic 3-D models of the human nasal passages were developed pre and post virtual uncinectomy and Middle Meatal Antrostomy. A 3-D computational domain was constructed by a series of coronal CT scan images from a healthy subject. Then a virtual uncinectomy intervention and maxillary antrostomy were performed on the left nasal passage by removing the uncinate process and exposing the maxillary sinus antrum. For several breathing rates corresponding to low or moderate activities, the airflows in the nasal passages were simulated numerically pre and post virtual routine maxillary sinus endoscopic surgery. The airflow distribution in the nasal airway, maxillary and frontal sinuses were analyzed and compared between pre and post surgery cases. A Lagrangian trajectory analysis approach was used for evaluating the path and deposition of microparticles in the nasal passages and maxillary sinuses. A diffusion model was used for nanoparticle transport and deposition analysis. The deposition rate of the inhaled micro and nanoparticles in the sinuses were evaluated and compared for pre and post operation conditions. The results showed that after maxillary sinus endoscopic surgery, the inhaled nano and microparticles can easily enter this sinus due to penetration of the airflow into the sinus cavity. This was in contrast to the preoperative condition in which almost no particles entered the sinuses. These results could be of importance for a better understanding of the effect of sinus endoscopic surgery on patient exposure to particulate pollution and inhalation drug delivery. The significantly higher airflow rate and particle deposition in the sinus could be a reason for the discomfort reported by some patient after maxillary sinus endoscopic surgery.