Finite element analyses for design evaluation of biodegradable magnesium alloy stents in arterial vessels
Finite element analyses for design evaluation of biodegradable magnesium alloy stents in arterial vessels
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DOI：
10.1016/j.mseb.2011.03.013
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发表时间：
2011-12-15
影响因子：
3.6
通讯作者：
Migliavacca, Francesco
中科院分区：
文献类型：
--
作者：
Wu, Wei;Gastaldi, Dario;Migliavacca, Francesco
可生物降解镁合金支架(MAS)可以为病变血管提供极大的益处，避免血管与永久支架平台之间长期不相容的相互作用。然而，现有的MAS由于降解时间较短，对靶血管的支架作用不足。本研究将AZ31的三维有限元模型与可降解材料模型(Al0.03，Zn0.01，Mn 0.002，镁平衡，质量百分比)相结合，应用于三种不同的支架设计，包括已植入支架(支架A)、优化设计(支架B)和专利支架设计(支架C)。每个设计的一个环通过在血管模型中的模拟被植入，然后随着外支架表面和血管之间相互作用的变化而退化。结果表明，与支架A相比，合适的支架设计(支架B)可以使血管的半归一化反冲时间增加近120%；此外，数值验证了MAS设计具有更大的质量和优化的力学性能，可以延长支架时间的期望。支架C的材料比支架B多，但由于应力集中比支架B大得多，血管的半归一化反冲时间仅比支架A提高近50%。三维模型为新型镁合金支架的设计和测试提供了方便的工具。(C)2011爱思唯尔B.V.保留所有权利。
Biodegradable magnesium alloy stents (MAS) can provide a great benefit for diseased vessels and avoid the long-term incompatible interactions between vessels and permanent stent platforms. However, the existing MAS showed insufficient scaffolding to the target vessels due to short degradation time. In this study, a three dimensional finite element model combined with a degradable material model of AZ31 (Al 0.03, Zn 0.01, Mn 0.002 and Mg balance, mass percentage) was applied to three different MAS designs including an already implanted stent (Stent A), an optimized design (Stent B) and a patented stent design (Stent C). One ring of each design was implanted through a simulation in a vessel model then degraded with the changing interaction between outer stent surface and the vessel. Results showed that a proper stent design (Stent B) can lead to an increase of nearly 120% in half normalized recoil time of the vessel compared to the Stent A; moreover, the expectation that the MAS design, with more mass and optimized mechanical properties, can increase scaffolding time was verified numerically. The Stent C has more materials than Stent B; however, it only increased the half normalized recoil time of the vessel by nearly 50% compared to the Stent A because of much higher stress concentration than that of Stent B. The 3D model can provide a convenient design and testing tool for novel magnesium alloy stents. (C) 2011 Elsevier B.V. All rights reserved.