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Flow instability and wall shear stress variation in intracranial aneurysms
H Baek1, M V Jayaraman, P D Richardson
1Division of Applied Mathematics, Brown University, Providence, RI 02912, USA.
Journal of the Royal Society, Interface
|December 22, 2009
Summary
High-resolution simulations reveal that blood flow in intracranial aneurysms can become unstable, causing high-frequency oscillations in wall shear stress (WSS) vectors. This instability occurs even at low flow rates, impacting aneurysm hemodynamics.
Area of Science:
- Biomedical Engineering
- Fluid Dynamics
- Medical Imaging
Background:
- Intracranial aneurysms pose significant health risks.
- Understanding blood flow dynamics within aneurysms is crucial for predicting rupture risk.
- Wall shear stress (WSS) is a key hemodynamic factor implicated in aneurysm progression.
Purpose of the Study:
- To investigate the flow dynamics and oscillatory behavior of wall shear stress (WSS) vectors in patient-specific intracranial aneurysms.
- To analyze the impact of aneurysm characteristics on flow instability and WSS fluctuations.
- To identify the frequency range of oscillations during hydrodynamic instability.
Main Methods:
- High-resolution numerical simulations of blood flow.
- Analysis of three distinct patient-specific internal carotid artery models with aneurysms.
- Examination of flow patterns and WSS vector behavior during the cardiac cycle.
Main Results:
- Pulsatile flow in aneurysms can exhibit hydrodynamic instability during the decelerating systolic phase.
- High-frequency oscillations (20-50 Hz) in WSS were observed, even at low parent vessel flow rates.
- Unstable flow leads to significant spatio-temporal fluctuations in WSS magnitude and direction, particularly in impingement regions.
Conclusions:
- Aneurysmal flow instability can induce high-frequency WSS oscillations.
- These WSS fluctuations may play a role in aneurysm development and rupture.
- Detailed hemodynamic analysis is essential for understanding aneurysm pathophysiology.
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