【摘要】 目的 为降低下肢动脉支架内再狭窄的发生，基于下肢动脉运动形态学设计新型动脉支架，研究其几何结构对力学性能的影响，为下肢动脉支架的结构设计和临床介入治疗提供理论依据和数据支撑。方法 建立5种镍钛合金下肢动脉支架模型，支撑体有两种椭圆结构(短轴沿轴向，长轴沿轴向),支撑体两侧设计为有无弧形件；连接体采用不同螺旋升角的螺旋线或直杆。通过有限元数值模拟方法，分析支架支撑性能(径向压握、平板压缩)及柔顺性能(弯曲、轴向压缩和扭转),并比较在单一和综合力学环境(弯曲、轴向压缩及扭转耦合作用)下支架的柔顺性能。结果 支架4(相邻两层支撑体椭圆短轴沿轴向且弧形件之间3根螺旋线)同时具有最为优异的支撑性和良好的柔顺性；支架5(连接体是直杆)的支撑性能和柔顺性能最差。支架2(相邻两层支撑体之间4根螺旋线且弧形件交错排列)的径向支撑性能是支架3(无弧形件)的1.3倍，但两者的平板压缩性能无明显差异，且均优于支架1(相邻两层支撑体之间4根螺旋线且弧形件相对排列)。在单一和综合力学环境下，支架2、3的弯曲和轴向压缩性能相近。在纯扭转作用下，支架3扭矩是支架2的2.5倍；而在综合力学环境下，支架3的扭矩仅为支架2的0.86倍，且两者柔顺性能均优于支架1。结论 支架的径向支撑性能主要受支撑体几何形状的影响，而平板压缩性能则由压缩平板中间的支撑体与连接体共同决定。支撑体中椭圆短轴沿轴向布置以及弧形件交错排列的设计可显著提升支架的支撑性能；连接体采用螺旋线结构则有助于改善支架的柔顺性能，且螺旋线的扭转方向不会对支架的扭矩产生较大的影响。更多还原

【Abstract】 Objective To reduce the occurrence of in-stent restenosis in lower limb arteries, a novel arterial stent was designed based on the kinematic morphology of lower limb arteries, and the effect of geometry on its mechanical properties was investigated, aiming to provide theoretical basis and data support for the structural design of lower limb arterial stents and clinical interventions. Methods Five nitinol lower limb arterial stents were established. The stent’s struts had two elliptical structures(short axis along the axial direction and long axis along the axial direction), with the presence or absence of arc-shaped components on both sides, and the connectors were helixes and straight rods with different helix angles of lift. The finite element numerical simulation method was utilized to investigate the stent support performance(radial crimping and flat plate compression) and the flexibility performance(bending, axial compression, and torsion), and the flexibility performance of the stents in the single and combined mechanical environments(bending, axial compression and torsion) was compared. Results Stent 4(with elliptical structures oriented with short axis along the axial direction and three helical lines between the arc-shaped components) offered the best support and flexibility, while Stent 5(with straight rods as connectors connecting body) had the worst support and flexibility. Stent 2(with 4 helical lines between adjacent layers of struts and arc-shaped components arranged alternately) had radial strength performance that was 1.3 times that of Stent 3(without arc-shaped components), but there was no significant difference in their planar compression performance, and both outperformed Stent 1(with 4 helical lines between adjacent layers of struts and arc-shaped components arranged in parallel). Under single or combined mechanical environment, the bending and axial compression performance of Stent 2 and Stent 3 was similar. The torque of Stent 3 was 2.5 times that of Stent 2 under pure torsion, but it was 0.86 times that of Stent 2 under the comprehensive mechanical environment, and both Stent 2 and Stent 3 were better than Stent 1 in terms of flexibility performance. Conclusions The radial strength of the stent is mainly affected by the geometry of the struts, and the flat plate compression performance is co-determined by the the struts and the connectors located within the compressed region. The short axis of the ellipse in the struts along the axial and curved pieces of the staggered arrangement of the design can significantly enhance the stent’s support performance. Meanwhile, the connectors with the helixes can effectively improve the stent’s flexibility performance, while the twisting direction of the helix has a minimal impact on torsional resistance.更多还原