Changes in Nasal Anatomy and Airflow After Endoscopic Resection of Pituitary Adenomas Using Computational Fluid Dynamics: A Pilot Study.

PURPOSE

Pituitary adenoma, a relatively common intracranial tumor, is often treated surgically through the nasal cavity, which alters its anatomy. This study aims to determine the severity of these changes in airflow and flow distribution within the nasal cavity, focusing on the anterior nasal region's role in airflow redistribution. Computational fluid dynamics (CFD) was employed to analyze these changes before and after surgery.

METHODS

Data from four patients of the Department of Neurosurgery and Neuro-oncology of the Military University Hospital, Prague, were analyzed using CFD simulations in Ansys Fluent 2021 R1. Computed tomography (CT) scans were used to model the nasal cavities pre- and post-surgery, creating polyhedral meshes of 1.8 million cells before surgery and 2.2 million cells after surgery. The k-ε turbulent model was applied to compute flow fields, providing consistent results across patients.

RESULTS

The surgery increased the nasal cavity volume, primarily due to the endonasal transsphenoidal approach. Cross-sectional areas, particularly in the middle nasal meatus, were enlarged, reducing airflow velocity without altering total volume flow. Most airflow was redistributed through the middle nasal meatus, while flow in peripheral regions decreased. The anterior part of the nasal cavity was identified as having the most significant influence on airflow redistribution.

CONCLUSION

Surgery impacts nasal anatomy and airflow dynamics significantly, particularly in the anterior part of the nasal cavity. These findings emphasize the need for surgical precision to minimize unintended shifts in airflow patterns. Further studies are recommended to validate these observations.