Modeling Nasal Physiology Changes due to Septal Perforations.

Objective: Some surgical procedures intentionally create asymptomatic septal perforations or inadvertently produce problematic ones. The purpose of this study is to use computational fluid dynamics (CFD) technology to help providers understand 1) how septal perforations alter nasal physiology, and 2) how this is influenced by perforation size and location. Method: Septal perforations of 1 and 2 cm were virtually created in a nasal cavity digital model in anterior, posterior, and superior (similar to a modified Lothrop procedure) locations. CFD technology was used to analyze airflow, conditioning, and wall shear stress. Results: Total nasal resistance was not significantly altered by septal perforations. Airflow allocation changed, with more airflow through the lower-resistance nasal cavity. This effect was less in the superior perforations compared to the other locations. There was less localized heat and moisture fluand wall shear stress in superior perforations compared to those in anterior or posterior locations. For anterior perforations, larger size (2 cm) correlated with 59% higher velocity and 22% greater wall shear, while the reverse relationship was seen in posterior perforations, with 5% higher velocity and 29% greater wall shear in the smaller perforation (1 cm). Conclusion: Septal perforations may alter nasal physiology. Airflow allocation is changed as air is shunted through the perforation to the lower-resistance nasal cavity. Superior perforations cause less alteration in nasal physiology than those in other locations. Larger anterior and smaller posterior perforations cause greater alterations in velocity and wall shear.