A Numerical Study of Empty Nose Syndrome: an Evaluation of Nasal Aerodynamics

Abstract

Empty nose syndrome (ENS) is a rare complication of nasal surgery done to enlarge the internal nasal channels. The feeling of nasal obstruction despite patency is one of the most common symptoms among ENS patients. This study was conducted using the CFD software STAR-CCM+ to offer an analysis and visualization of airflow patterns within the nasal cavity during inhalation and exhalation. In addition, deposition of inhaled particles and clearance in the nasal cavity were studied. Five numerical models of nasal cavities from different patients were constructed. For two of the cases, the patients had confirmed ENS, other two have an obstruction in the nasal cavity, and the final one is completely healthy. The results of the analysis showed for one ENS geometry a very low resistance during both inhalation and exhalation when compared to the other cases. Furthermore, all the geometries except the healthy one, showed a lower resistance at exhalation than at inhalation. The study on particle deposition revealed for one of the ENS geometries a low deposition ratio, which was significantly lower than for all the other geometries. Further, for the other ENS geometry showed a lower particle deposition ratio after developing ENS. Loss of nasal mucosa was suggested as a possible cause for the low particle deposition ratio, but this needs further investigation.