Wall Shear Stress and Pressure Distribution on Aneurysms and Infundibulae in the Posterior Communicating Artery Bifurcation
Wall Shear Stress and Pressure Distribution on Aneurysms and Infundibulae in the Posterior Communicating Artery Bifurcation
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DOI：
10.1007/s10439-009-9794-y
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发表时间：
2009-12-01
影响因子：
3.8
通讯作者：
Karniadakis, George Em
中科院分区：
文献类型：
--
作者：
Baek, Hyoungsu;Jayaraman, Mahesh V.;Karniadakis, George Em
越来越多的病例报道了在漏斗破裂，漏斗进展到一个坦率的动脉瘤，和蛛网膜下腔出血（SAH）在后交通动脉（PCoA）。利用具有PCoA漏斗或动脉瘤的颈内动脉上突（ICA）患者特异性几何模型，采用谱/hp元方法求解Navier-Stokes方程，进行高分辨率计算流体动力学模拟。模拟结果表明，流动在靠近ICA弯道外侧的漏斗远端壁处撞击，形成一个高压区域（4-5 mmHg），周围是一个高壁剪切应力（WSS）带（平均20-30 N/m(2)）。在漏斗近端形成另一个低WSS （< 1 N/m(2)）和高振荡剪切指数的停滞区。撞击区似乎与大管破裂或发展为动脉瘤的位置一致。此外，由于动脉瘤或动脉瘤样小泡的存在，脉动血流变得不稳定，这导致动脉瘤内WSS时间波动，这可能加速血管壁的退行性过程。
A growing number of cases of rupture at an infundibulum, progression of infundibulum to a frank aneurysm, and subarachnoid hemorrhage (SAH) in the posterior communicating artery (PCoA) have been reported. Using patient-specific geometric models of the supraclinoid internal carotid artery (ICA) with PCoA infundibulum or aneurysm, high-resolution computational fluid dynamics simulations were performed by solving the Navier-Stokes equations with a spectral/hp element method. Simulation results show that the flow impinges at the distal wall of infundibulum near the outside of the ICA bend and creates a region of higher pressure (4-5 mmHg) surrounded by a band of a high wall shear stress (WSS) (20-30 N/m(2) on average). At the proximal end of the infundibulum, another stagnation area is formed characterized by low WSS (< 1 N/m(2)) and high oscillating shear index. This impingement region seems to coincide with the locations of the rupture of infundibulae or progression to aneurysms. In addition, the pulsatile flow becomes unstable due to the presence of aneurysms or aneurysm-like infundibulae, and this leads to WSS temporal fluctuations inside the aneurysm, which may accelerate the degenerative processes in the vessel walls.