Local Hemodynamic Conditions Associated with Focal Changes in the Intracranial Aneurysm Wall

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Imaging

Background:

• Aneurysm hemodynamics is linked to wall histology and inflammation.
• Investigated associations between local hemodynamics and focal wall changes visible intraoperatively.

Purpose of the Study:

• To investigate associations between local hemodynamics and focal wall changes visible intraoperatively.
• To correlate specific hemodynamic parameters with distinct visual wall characteristics in aneurysms.

Main Methods:

• Constructed computational fluid dynamics (CFD) models from 3D images of 65 surgically treated aneurysms.
• Identified and marked aneurysm regions (atherosclerotic, hyperplastic, thin, rupture site, normal) on 3D reconstructions based on intraoperative videos.
• Compared regional hemodynamics (wall shear stress, oscillatory shear index, relative residence time, etc.) using the Mann-Whitney test.

Main Results:

• Hyperplastic regions showed lower average wall shear stress and pressure compared to normal regions.
• Atherosclerotic and hyperplastic regions exhibited higher relative residence time and oscillatory shear index than thin regions.
• Thin regions displayed lower relative residence time, oscillatory shear index, and gradient oscillatory number, with higher wall shear stress and pressure than hyperplastic regions.

Conclusions:

• Local hemodynamics is associated with visible focal wall changes in aneurysms.
• Slow, swirling flow with low and oscillatory wall shear stress correlates with atherosclerotic and hyperplastic wall changes.
• High flow conditions, characterized by higher and less oscillatory wall shear stress, are associated with local wall thinning.