The Nasal Aerodynamic Study Of Empty Nose Syndrome

ObjectiveThis study aims to investigate the nasal aerodynamic characteristics and changes of Empty Nose Syndrome-Inferior Turbinate (ENS-IT) and-Middle Turbinate (ENS-MT), the two typical subtypes of ENS, and to preliminarily explore the role of the aerodynamic changes on the pathogenesis of ENS.Methods7anatomically high-resolution sinonasal models were constructed by computational fluid dynamics (CFD) simulation, based on the computed tomography (CT) images of7healthy male adults. Bilateral radical inferior/middle turbinectomy were numerically performed respectively, to mimic ENS-IT and ENS-MT. A steady-state and laminar model was applied in the calculation. Velocity, pressure, trajectories, air flux and wall shear stress were numerically investigated and compared in the normal, ENS-IT and ENS-MT airflow fields.Results1.(1) ENS-MT Inspiration:Air flux, trajectories and wall shear stress distributions are relatively similar to those in the physiological airflow field, nasal resistances decrease, velocities decrease in the post-median nasal cavities. Velocities around the sphenopalatine ganglion increase in some subjects.(2) ENS-MT Expiration:Velocities around the sphenopalatine ganglion increase, other trends are similar to those of ENS-MT inspiration.2.(1) ENS-IT Inspiration:Most airflow passes through the former inferior turbinate areas, trajectories are less organized, areas with larger wall shear stress shrink, nasal resistances decrease, velocities decrease in the anterior and post-median nasal cavities.(2) ENS-IT Expiration:Changing trends are similar to those of ENS-IT inspiration.Conclusion1. The nasal aerodynamic characteristics change greatly after the bilateral radical inferior turbinectomy. Relatively mild changes happen after the bilateral radical middle turbinectomy; however, velocity around the sphenopalatine ganglion significantly increases, possibly leading to the pain associated with breathing. Therefore, radical turbinectomy should be performed by following the indications strictly.2. Nasal aerodynamic study is an effective tool to predict the aerodynamic changes of individual patients after sinonasal operations.3. Multiple factors are responsible for the ENS occurrence. Nasal aerodynamic changes can partially explain its occurrence. Further studies are in need to establish the more definite relationship between aerodynamic changes and the clinical manifestations of ENS.4. Individuals of the same race and in the similar climatic condition share some similar nasal aerodynamic changes after bilateral radical middle/inferior turbinectomy.