靶向药物洗脱支架压握过程的力学性能

目的 研究两种不同结构的药物洗脱支架（drug eluting stent, DES）压握过程的力学性能，以期对DES结构设计提供科学的指导。方法 采用Solidworks软件分别建立支架外表面没有刻槽的传统DES（I型支架）以及支架外表面有刻槽的靶向DES（II型支架）；通过ABAQUS有限元分析软件，对两种支架压握过程中的径向紧缩反弹比、轴向紧缩反弹比、压握不均匀性、残余应力分布等重要的力学性能指标进行分析。结果 同一紧缩外径条件下，两种支架径向紧缩反弹比、轴向紧缩反弹比以及压握不均匀性指数的差值分别在0.07%~0.12%、0.016%~0.033%、0.013%~0.048%之间，II型支架支撑体上存在面积更大的低应力区域。结论 相比传统DES支架，靶向DES支架在减少载药量的同时，力学性能并未降低，对心血管狭窄等疾病的治疗具有较好的临床应用前景。

Mechanical performance of targeted drug eluting stent during compression process

Objective To investigate mechanical performances of two different drug eluting stents (DES) during compression process, so as to provide a scientific guideline for design of DES. Methods Using Solidworks, two kinds of stent models, namely the common DES without slots in outside surface (Stent I) and the targeted DES with slots in outside surface (Stent II) were established, respectively. The important mechanical properties of the two stents during compression process, such as rebound ratio of radial contraction, rebound ratio of axial contraction, the inhomogeneity of compression and the distribution of residual stress, were analyzed by ABAQUS. Results With the same outer radius, the difference values of rebound ratio of radial contraction, rebound ratio of axial contraction and inhomogeneity of compressing for the two stents were 0.07%-0.12%, 0.016%-0.033% and 0.013 %-0.048%, respectively; there was a bigger low-stress area on the support of Stent II. Conclusions Compared with the traditional DES, the targeted DES could maintain the same mechanical performances while reducing drug-loading capacity, which shows a good prospect in clinical application of the treatment for cardiovascular stenosis diseases.