Influence of Functional Endoscopic Sinus Surgery on Airflow of Postoperative Nasal Cavity and Sinuses

【Objective】To study the characteristics of the airflow-field parameter in nasal cavity and sinuses after functional endoscopic sinus surgery (FESS) by computational fluid dynamics (CFD). 【Methods】 A subject was selected strictly from 30 healthy young people through nasal endoscopic examination, acoustic rhinometry measurement and CT scanning. Based on the CT image data of the subject, digital model of normal nasal cavity was reconstructed through Fluent 6.1.22 software. At the same time, according to the surgical requirements of FESS (remove the uncinate process and open the ethmoid sinus, maxillary sinus, and sphenoid sinus), post-FESS digital nasal cavity model was simulated. The viscous motion of nasal airflow before and after FESS was calculated by Navier-Stokes equations to compare the differences of airflow velocity, distribution, and pressure. 【Results】 In the post-FESS digital nasal cavity model, airflow through common nasal meatus decreased obviously but increased over 13% through middle nasal meatus and open ethmoid sinus. The airflow velocity in maxillary sinus, ethmoid sinus, and the anterior part of sphenoid sinus was all more than 0.01 m / s. In the middle-upper part of maxillary sinus, the airflow velocity was over 0.1m/s and an obvious annular flow was observed. Resistance in the post-FESS digital nasal cavity model diminished mainly in the middle and posterior parts of the operational cavity. 【Conclusion】 The airflow dynamic parameters of pre- and post-FESS nasal cavity models are different which proves that FESS changes some natural physiological mechanic characteristics of nasal cavity.