血管支架有限元优化设计

血管支架植入术是目前治疗冠心病的最流行手段,但现行支架较高的再狭窄率成为其进一步发展的最大障碍.通过对血管支架进行结构优化设计,改变其安放时的膨胀行为则是一个能够减少支架在植入时对血管内膜的损伤,从而降低支架内再狭窄率的有效途径之一.我们利用有限元技术,系统地模拟分析了支架不同环状支撑体宽度以及整体的非对称设计对其瞬时膨胀行为的影响.结果显示,在支架的结构参数中环状支撑体的宽度对支架膨胀压影响显著,在设计血管支架时,其环状支撑体结构的非对称设计,即环状支撑体的宽度从中部到端部依次逐渐递减变化,可以有效抑制了球囊伎架系统在瞬时膨胀过程中的"狗骨头"现象,从而达到减小对血管壁急性损伤的目的.

Design Optimization of Endovascular Stent by Finite Element Method

Stent implantation is now the favorable therapy of coronary heart disease, but the restenosis occurring in association with the currently used stents device has become the main obstacle limiting the further development of stent. To change the expanding behavior of endovascular stents by way of design optimization is considered one of the effective approaches for reducing the damage to the intima of blood vessel and thereby decreasing the in-stent restenosis. So in this paper, the finite element method was used to systematically simulate and analyze the influences of different width of ring supporter and the non-symmetrical design of stent on its transitorily expanding behavior. The results show that among the structure parameters, the width of ring supporter of stent influences its expanded pressure remarkably. When designing the endovascular stent, we make its ring supporter unsymmetrical, i. e., we make the width of ring supporter of stent change degressively from its central part to end part. By this means, the dogboning, which normally happens in the expanding process of the balloon/stent system, can be effectively controlled and the acute vascular injuries can be reduced.