脳動脈瘤内拍動流れに及ぼす血管弾性変形の影響

抄録

The effect of elasticity on the wall shear stress and the flow characteristic inside the cerebral aneurysm induced at the apex of bifurcation was experimentally investigated by the two-dimensional particle image velocimetry (2D-PIV) in vitro. The geometry of the aneurysm model used in the experiment was based on a patient-specific shape reconstructed from magnetic resonance images (MRI). Flow model simulates a patient-specific aneurysm induced at the apex of bifurcation in the middle cerebral artery. The elastic wall of the aneurysm model was constituted of transparent silicon rubber thickness 1mm. The maximum deformation rate of PIV measurement section was about 5~8%. These characteristics were examined for both elastic and rigid aneurysm models in pulsatile blood flow wave. The effect of wall elasticity on velocity of inlet flow was noticed in comparison with that of wall rigidity. We found that the wall deformation significantly reduced by several tens percent of the spatial and temporal averaged velocity of inlet flow in comparison with the non-deformable wall, and its maximum values in the elastic model is remarkably suppressed. Consequently, the elasticity of aneurysm wall significantly suppresses the magnitude, the spatial and temporal averaged velocity of inlet flow in comparison with the non-deformable wall.