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Wall shear stress distribution inside growing cerebral aneurysm
T Tanoue1, S Tateshima, J P Villablanca
1Department of System Design Engineering, Keio University Faculty of Science and Technology, Yokohama, Japan. moonlight_game@diamond.broba.cc
AJNR. American Journal of Neuroradiology
|October 11, 2011
Summary
Hemodynamic factors influence cerebral aneurysm growth. Reduced wall shear stress (WSS) and increased WSS gradients (WSSG) at the growing region indicate higher risk for aneurysm expansion.
Area of Science:
- Cerebrovascular research
- Biomedical engineering
- Fluid dynamics
Background:
- Hemodynamic forces are implicated in cerebral aneurysm development.
- Understanding intra-aneurysmal hemodynamics is crucial for predicting aneurysm growth.
Purpose of the Study:
- To investigate the relationship between intra-aneurysmal hemodynamics and cerebral aneurysm growth.
- To compare hemodynamic profiles in growing versus non-growing aneurysms.
Main Methods:
- Patient-specific aneurysm models created from CT angiograms.
- Particle image velocimetry and LDV used to measure flow fields and wall shear stress (WSS).
- Hemodynamic changes tracked over 27 months in a growing aneurysm case.
Main Results:
- Growing aneurysms exhibited smaller, more stagnant recirculation zones compared to non-growing ones.
- Reduced WSS was observed in the enlarging regions of growing aneurysms.
- Higher WSS gradients (WSSG) were consistently found adjacent to the growing regions.
Conclusions:
- Recirculation flow alone does not guarantee aneurysm growth.
- Distinct differences in WSS and WSSG differentiate growing from non-growing cerebral aneurysms.
- Extremely low WSS at the growing region and higher WSSG surrounding it are key indicators of aneurysm expansion.
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