A computational fluid dynamics analysis of the effects of size and shape of anterior nasal septal perforations

Abstract

Background: Nasal septal perforations (NSPs) often cause bleeding, crusting, obstruction, and/or whistling. The objective was to analyze the impact of anterior NSP size and shape on nasal physiology using computational fluid dynamics (CFD). Methods:A 3-dimensional model of the nasal cavity was constructed from a radiologically normal CT scan using imaging software. Anterior NSPs (ovoid (ONSP): 0.5, 1, 2, and 3 cm long anterior-to-posteriorly and round (RNSP, 0.5 and 1 cm)) were virtually created in the model and divided into ventral, dorsal, anterior, and posterior regions. Steady-state inspiratory airflow, heat, and water vapor transport were simulated using Fluent™ CFD software. Air crossover through the perforation, wall shear, heat flux, water vapor flux, resistance, and humidification were analyzed.Results: Air crossover and wall shear increased with perforation size. Regionally, wall shear and heat and water vapor flux were highest posteriorly and lowest anteriorly, generally increasing with size in those regions. RNSPs had greater heat and water vapor flux compared to corresponding size ONSPs. Resistance decreased by 10% or more from normal only in the 3 cm ONSP. Maximum water content was achieved more posteriorly in larger NSP nasal cavities. Conclusions:High wall shear and heat and water vapor flux in posterior perforation regions may explain the crusting most commonly noted on posterior NSP edges. This preliminary study suggests that larger NSPs have a greater effect on nasal resistance and water content. Decrease in resistance with larger NSP size may be implicated in reported symptomatic improvement following enlargement of NSPs for treatment.

Nasal airflow of patient with septal deviation and allergy rhinitis

“…The pressure-based model was adopted for this simulation, as the density of air was assumed to be constant throughout the geometry [ 25 ]. The flow of mucus was not considered owing to its minimal thickness and low velocity [ 23 , 26 ]. The mesh models of the three meshing types for the mesh dependency study (Fig.…”

Computational technology for nasal cartilage-related clinical research and application

“…112 Virtually creating septal perforations with different sizes in different locations can also be regarded as manipulating the part of the nasal cartilage complex, and CFD showed alterations in nasal physiology following these structural changes. 113,114 The above workflow provides an experimental procedure for analysing the effects of nasal cartilage changes on airway airflow, but it is worth mentioning that if the patient sample size is sufficient, researchers can choose to use individual patient image data before and after surgery for reconstruction and computational analysis. Furthermore, there is potential to modify the model in combination with structural mechanics analysis to simulate the surgical process and then perform CFD of the airway after the operation.…”

“… 112 Virtually creating septal perforations with different sizes in different locations can also be regarded as manipulating the part of the nasal cartilage complex, and CFD showed alterations in nasal physiology following these structural changes. 113 , 114 …”

Comparing nasal physiology after superior ethmoidal and traditional endoscopic anterior cranial base approaches

“…Computational fluid dynamics (CFD) is a useful tool to examine nasal physiology and has advantages over conventional methods (4,5) . A recent study has used CFD to demonstrate different airflow, wall shear stress (WSS), heat flux and humidifying efficiencies in patients following the TA compared to controls (6) .…”