Response to Dr Chung’s Question on Simulating the Nasal Cycle with Computational Fluid Dynamics

Abstract

I was pleased to read the interesting article by Patel and coauthors, "Simulating the Nasal Cycle with Computational Fluid Dynamics," published in your journal. 1 Decongestion of the nose is used as a way of stabilizing and evaluating nasal patency. 2 Nearly all patients feel patent nasal cavity after decongestion. The objective of this article was to develop a new method to quantify nasal surgery outcomes by simulating the nasal cycle to evaluate the exact condition of patients. Change in the thickness of turbinate mucosa is possible in the space between hard structures, such as septal bone or cartilage, and the bony portion of turbinate. Therefore, when a structure such as the septum is changed after operation, the range of swelling may change. However, in this article, postoperative computed tomography scanning was used to limit the congestion and decongestion of the turbinate in the preoperative nasal cycle model, so changes of the septum or turbinate did not need to be considered. It might have been more helpful to show the image in the maximally corrected plane in figure 1 and explain the method of dilation or erosion of the mask in that area. In figure 4, the sum of the cross-sectional areas in both nasal cavities increased 50% from 1.5 cm 2 to 2.25 cm 2 after surgery at D = 0. Is this an effect of the surgery? In figure 7, there may be confusion in the captions regarding the open and closed circles.

Estimates of nasal airflow at the nasal cycle mid-point improve the correlation between objective and subjective measures of nasal patency

“…The method requires the creation of multiple nasal cycle models for each surgical state (i.e., pre-surgery and post-surgery), running CFD simulations in each model, and fitting a curve to describe the relationship between flow variables and inferior turbinate thickness so that flow variables can be estimated at the mid-cycle. This method was previously applied to simulate the nasal cycle in two NAO patients and the results revealed that the nasal cycle can dramatically influence objective measures of surgical outcomes (Garcia et al, 2015a; Patel et al, 2015). …”