Chitanvis S M, Hademenos G, Powers W J
Theoretical Division, Los Alamos National Laboratory, NM 87545, USA.
Neurol Res. 1995 Dec;17(6):426-34.
Intracranial aneurysms manifest themselves as sacculations within a weakened region of the vessel wall and pose substantial neurological risks upon rupture. A primary factor in the development and rupture stages of an aneurysm is hemodynamics and its degrading effects on the aneurysm wall. Wall dynamics and hemodynamics within a fully developed aneurysm were investigated using computational simulation techniques. To study wall dynamics, the aneurysm was modeled as a thing spherical shell with linearly elastic and plastic (viscoelastic) wall behavior. The sensitivity of this model to the biophysical parameters which describe it will assist in the quantitative assessment of factors predisposing to aneurysm rupture and subarachnoid hemorrhage. Flow dynamics simulations were performed for spherical aneurysms with rigid walls. We observed the development and motion of an annular vortex within the lateral sacculation. We also simulated a ruptured aneurysm by placing a tear near the neck of the aneurysm. Flow patterns showed blood flowing out during the initial stages of the flow, but displayed an inflow of blood soon thereafter, as the internal pressure dropped. These results are substantiated by the clinical observations that turbulent flow is observed within the aneurysm as evidenced by reduced bruits.
颅内动脉瘤表现为血管壁薄弱区域的囊状扩张，破裂时会带来重大的神经学风险。动脉瘤发生和破裂阶段的一个主要因素是血流动力学及其对动脉瘤壁的降解作用。使用计算模拟技术研究了成熟动脉瘤内的壁动力学和血流动力学。为了研究壁动力学，将动脉瘤建模为具有线性弹性和塑性（粘弹性）壁行为的薄球壳。该模型对描述其的生物物理参数的敏感性将有助于对动脉瘤破裂和蛛网膜下腔出血的易感因素进行定量评估。对具有刚性壁的球形动脉瘤进行了流动动力学模拟。我们观察到侧囊内环形涡流的发展和运动。我们还通过在动脉瘤颈部附近放置一个裂口来模拟破裂的动脉瘤。流动模式显示在流动的初始阶段有血液流出，但随着内部压力下降，随后很快显示有血液流入。这些结果得到了临床观察的证实，即动脉瘤内观察到湍流，表现为杂音减弱。
