Mechanical behavior of coronary stents investigated through the finite element method
Mechanical behavior of coronary stents investigated through the finite element method
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DOI：
10.1016/s0021-9290(02)00033-7
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发表时间：
2002-06-01
影响因子：
2.4
通讯作者：
Pietrabissa, R
中科院分区：
文献类型：
--
作者：
Migliavacca, F;Petrini, L;Pietrabissa, R
血管内支架是扩张到狭窄动脉中以恢复下游组织的血流灌注的小管状结构。将支架安装在球囊导管上并输送到堵塞部位。当球囊膨胀时，支架膨胀并压靠在冠状动脉的内壁上。球囊放气并取出后，支架仍留在原位。保持动脉通畅因此，支架扩张定义了外科手术的有效性：它取决于支架的几何形状，它包括大的位移和变形以及材料的非线性。本文应用有限元方法（i）了解不同几何参数的影响（厚度、金属-动脉表面比、纵向和径向切割长度）对器械机械性能的影响，（ii）比较不同实际支架模型在内压作用下的响应;（iii）收集优化器械形状和性能的建议。结果显示了几何形状对支架性能的影响：金属与动脉表面比低的支架具有较高的径向和纵向回缩，但狗骨化较低。厚度影响支架性能方面的缩短，纵向回缩和dogboning.In结论，有限元分析类似于本文提出的一个可以帮助设计新的支架或分析实际的支架，以确保理想的扩张和结构的完整性，替代在体外实验往往是困难和不切实际的。(C)2002爱思唯尔科技有限公司版权所有。
Intravascular stents are small tube-like structures expanded into stenotic arteries to restore blood flow perfusion to the downstream tissues. The stent is mounted on a balloon catheter and delivered to the site of blockage. When the balloon is inflated, the stent expands and is pressed against the inner wall of the coronary artery. After the balloon is deflated and removed, the stent remains in place. keeping the artery open. Hence, the stent expansion defines the effectiveness of the surgical procedure: it depends on the stent geometry, it includes large displacements and deformations and material non-linearity.In this paper, the finite element method is applied (i) to understand the effects of different geometrical parameters (thickness, metal-to-artery surface ratio, longitudinal and radial cut lengths) of a typical diamond-shaped coronary stent on the device mechanical performance, (ii) to compare the response of different actual stent models when loaded by internal pressure and (iii) to collect suggestions for optimizing the device shape and performance.The stent expansion and partial recoil under balloon inflation and deflation were simulated. Results showed the influence of the geometry on the stent behavior: a stent with a low metal-to-artery surface ratio has a higher radial and longitudinal recoil, but a lower dogboning. The thickness influences the stent performance in terms of foreshortening, longitudinal recoil and dogboning.In conclusion, a finite element analysis similar to the one herewith proposed could help in designing new stents or analyzing actual stents to ensure ideal expansion and structural integrity, substituting in vitro experiments often difficult and unpractical. (C) 2002 Elsevier Science Ltd. All rights reserved.