Experimental evaluation of wall shear stress in an elastic cerebral aneurysm model

Pulsating flow within an elastic cerebral aneurysm model was visualized by particle image velocimetry (PIV) to clarify the effect of wall deformation on wall shear stress (WSS). In the experiment, we used a full-scale patient-specific cerebral aneurysm phantom model with a thin transparent silicone wall fabricated by soaking a plaster mold. The experiment was performed in two planes, one in the middle plane and the other perpendicular to it. The results showed that in the middle plane, the wall deformation reduced the maximum WSS in systole by about 20% and the averaged WSS by about 20% in comparison with the less-deformation model. On the other hand, for planes perpendicular to the aforementioned planes, the averaged WSS increased by about 10% in comparison with the less-deformation model. In addition, it was observed that the local WSS changed in intensity according to the plane and phase, because of movement of the separation point of the wall jet. This finding suggests that the wall deformation of cerebral aneurysm affects the magnitude of WSS.