球扩式介入主动脉瓣膜支架的抗迁移力学行为

目的 研究球扩式主动脉瓣膜支架植入后的抗迁移力学行为。 方法 建立球扩式瓣膜支架介入主动脉瓣膜后的抗迁移力学模型,采用数值模拟方法研究不同瓣环椭圆率、摩擦因数、瓣膜支架材料及自体瓣叶钙化情况对瓣膜支架抗迁移力的影响规律。 结果 当主动脉瓣环椭圆率为 0. 2、0. 3、0. 4、0. 5 时,对应的最大抗迁移力分别为12. 37、10. 94、8. 50、4. 75 N;当摩擦因数为 0. 1、0. 2、0. 3 时,瓣膜支架的最大抗迁移力分别为 8. 98、11. 00、13. 10 N;L605 钴铬合金制成的瓣膜支架的锚定性要优于 316L 不锈钢制成瓣膜支架的锚定性,其对应的最大抗迁移力分别为 13. 10、9. 82 N;当自体瓣叶发生钙化时,最大抗迁移力为 13. 1 N,而未钙化时最大抗迁移力仅为 5. 51 N,相比而言降低了 57. 9% 。 结论 随着主动脉瓣瓣环椭圆率不断增大,瓣膜支架的锚定性逐渐降低;随着瓣膜支架与组织间的摩擦因数不断增大,最大抗迁移力也不断增大;L605 钴铬合金制成的瓣膜支架比 316L 不锈钢制成瓣膜支架的锚定性能优异;瓣膜发生钙化情况下瓣膜支架的锚定性要优于未发生钙化时的锚定性。 研究结果为抗迁移瓣膜支架的结构设计和临床选择提供重要的科学依据。

Anti-Migration Mechanical Behavior of Balloon-Expanded Interventional Aortic Valve Stent

Objective To study the anti-migration mechanical behavior of balloon-expanded aortic valve stent afteimplantation. Methods The mechanical model of anti-migration of balloon-expanded valve stent after interventional treatment of aortic valve was established. The effects of different valve ring ellipticity, friction coefficient, valve stent material and calcification of autogenous valve leaflet on anti-migration of valve stent were studied by numerical simulation method. Results When the ellipticity of aortic valve ring was 0. 2, 0. 3, 0. 4 and 0. 5, the corresponding maximum anti-migration force was 12. 37, 10. 94, 8. 50 and 4. 75 N, respectively. When the friction coefficient was 0. 1, 0. 2 and 0. 3, the maximum anti-migration force of valve stent was 8. 98, 11. 00 and 13. 10 N, respectively. The anchoring performance of valve stent made of L605 cobalt-chromium alloy was better than that made of 316L stainless steel, and its corresponding maximum anti-migration force was 13. 10, 9. 82 N, respectively. When the autogenous valve was calcified, the maximum anti-migration force was 13. 1 N. When the autogenous valve was not calcified, the maximum anti-migration force was only 5. 51 N, decreased by 57. 9% . Conclusions With the increase in ellipticity of aortic valve ring, the anchoring of valve stent decreases gradually. As the friction coefficient between the valve stent and the tissue increases, the maximum anti-migration force also increases. The anchoring performance of valve stent made of L605 cobalt-chromium alloy is superior to that made of 316L stainless steel. The anchoring of valve stent with calcification is better than that without calcification. The results in this study provide an important scientific basis for structural design and clinical selection of anti-migration valve stent.