Numerical study of the aerodynamic effects of septoplasty and partial lateral turbinectomy.

To investigate, first, the effects of septal deviation and concha bullosa on nasal airflow, and second, the aerodynamic changes induced by septoplasty and partial lateral turbinectomy, using computational fluid dynamics (CFD). A three-dimensional model of a nasal cavity was generated using paranasal sinus computed tomography images of a cadaver with concha bullosa and septal deviation. Virtual septoplasty and partial lateral turbinectomy were performed on this model to generate a second model representing the postoperative anatomy. Aerodynamics of the nasal cavity in the presence of concha bullosa and septal deviation as well as postoperative changes due to the virtual surgery were analyzed by performing CFD simulations on both models. Inspiratory airflow with a constant flow rate of 500 mL/second was used throughout the analyses. In the preoperative model, the airflow mostly pass through a narrow area close to the base of the nasal cavity. Following the virtual operation, a general drop in the maximum intranasal air speed is observed with a significant increase of the airflow through right middle meatus. While in the preoperative model the greatest reduction in pressure is found to be in the localization of anterior septal deviation on the right side and confined to a very short segment, for the postoperative model, it is observed to be in the nasal valve region in both nasal cavities. Following septoplasty and partial lateral turbinectomy, total nasal resistance is reduced significantly. CFD simulations promise to make great contributions to understand the airflow characteristics of healthy and pathologic noses. Before surgery, planning for any specific intervention using CFD techniques on the nasal cavity model of the patient may help foreseeing the aerodynamic effects of the operation and might increase the success rate of the surgical treatment.