Toward personalized nasal surgery using computational fluid dynamics

Abstract

Objective: To evaluate whether virtual surgery performed on 3-dimensional (3D) nasal airway models can predict postsurgical, biophysical parameters obtained by computational fluid dynamics (CFD).

Methods: Presurgery and postsurgery computed tomographic scans of a patient undergoing septoplasty and right inferior turbinate reduction (ITR) were used to generate 3D models of the nasal airway. Prior to obtaining the postsurgery scan, the presurgery model was digitally altered to generate 3 virtual surgery models: (1) right ITR only, (2) septoplasty only, and (3) septoplasty with right ITR. The results of the virtual surgery CFD analyses were compared with postsurgical CFD outcome measures including nasal resistance, unilateral airflow allocation, and regional airflow distribution.

Results: Postsurgery CFD analysis and all virtual surgery models predicted similar reductions in overall nasal resistance, as well as more balanced airflow distribution between sides, primarily in the middle region, when compared with the presurgery state. In contrast, virtual ITR alone produced little change in either nasal resistance or regional airflow allocation.

Conclusions: We present an innovative approach for assessing functional outcomes of nasal surgery using CFD techniques. This preliminary study suggests that virtual nasal surgery has the potential to be a predictive tool that will enable surgeons to perform personalized nasal surgery using computer simulation techniques. Further investigation involving correlation of patient-reported measures with CFD outcome measures in multiple individuals is under way.

FIGURE 1

Diagram of CFD workflow used to generate the various computational models.

FIGURE 2

(a) Coronal cross sections at four locations (A, B, C, D) illustrating the anatomic differences among the computer models. (b) Para-saggital 3D nasal reconstruction showing location of coronal planes illustrated in 2a. (c) Representative coronal cross-section identifying location of the inferior turbinates, middle turbinates, and septum.

FIGURE 3

Three-dimensional nasal reconstructions and left saggital views of the nasal septum. Colored regions indicate the area of the septum modified in the virtual surgery and post-surgery models.

FIGURE 4

Overall, right hand side (RHS), and left hand side (LHS) nasal resistance values calculated using CFD.

FIGURE 5

CFD-calculated airflow allocation between the right hand side (RHS) and left hand side (LHS) of the nose.

FIGURE 6

CFD-calculated regional airflow distribution between the dorsal, middle, and ventral regions of the nose on the left and right sides.