Modeling nasal physiology changes due to septal perforations.

Objective: To use computational fluid dynamics (CFD) technology to help providers understand (1) how septal perforations may alter nasal physiology and (2) how these alterations are influenced by perforation size and location.

Study Design: Computer simulation study.

Setting: Facial plastic and reconstructive surgery clinic.

Subjects And Methods: With the aid of medical imaging and modeling software, septal perforations of 1 and 2 cm in anterior, posterior, and superior locations were virtually created in a nasal cavity digital model. The CFD techniques were used to analyze airflow, nasal resistance, air conditioning, and wall shear stress.

Results: Bilateral nasal resistance was not significantly altered by a septal perforation. Airflow allocation changed, with more air flowing through the lower-resistance nasal cavity. This effect was greater for anterior and posterior perforations than for the superior location. At the perforation sites, there was less localized heat and moisture flux and wall shear stress in superior perforations compared with those in anterior or posterior locations. For anterior perforations, a larger size produced higher wall shear and velocity, whereas in posterior perforations, a smaller size produced higher wall shear and velocity.

Conclusion: Septal perforations may alter nasal physiology. In the subject studied, airflow allocation to each side was changed as air was shunted through the perforation to the lower-resistance nasal cavity. Anterior and posterior perforations caused larger effects than those in a superior location. Increasing the size of anterior perforations and decreasing the size of posterior perforations enhanced alterations in wall shear and velocity at the perforation.