Lucchetti Agnese, Juhl Levi G, Corti Anna, Zaccaria Alissa, Gries Thomas, Chiastra Claudio, Vaughan Ted J, Carbonaro Dario
Institut für Textiltechnik of RWTH Aachen University, Aachen, Germany.
Department of Electronics, Information and Bioengineering, Milan, Italy.
Int J Numer Method Biomed Eng. 2025 Aug;41(8):e70078. doi: 10.1002/cnm.70078.
Bioresorbable braided stents represent a promising solution for the treatment of peripheral artery disease, providing temporary mechanical support before gradually degrading into biocompatible byproducts. Previous studies have highlighted their lower mechanical performance compared to permanent metallic stents. However, their implantation in lower limb arteries remains unexplored, leaving uncertainty on whether their mechanical performance is sufficient for effective treatment. The aim of the present study was to evaluate the performance of a poly-l-lactic acid (PLLA) braided stent for the treatment of lower limb arteries through in silico analysis and compare it with that of a nickel-titanium (NiTi) device. A finite element (FE) model of the PLLA stent was implemented and validated against experimental bench test data. Subsequently, the mechanical characteristics of the PLLA device were compared to those of a NiTi stent, with identical geometrical features, through FE simulations of two bench tests (i.e., parallel plate compression and crimping tests). Finally, a virtual implantation procedure of both devices in a patient-specific lower limb artery was conducted by FE analysis, accounting for three different arterial wall conditions, to compare the stents' treatment performance. The FE analysis of the bench tests confirmed that the PLLA stent generated much lower force magnitudes than the NiTi device. Moreover, the virtual implantation procedure indicated the limited short-term performance of the PLLA stent for the treatment of peripheral artery disease in terms of risk for permanent deformations, low lumen gain, high values of incomplete stent apposition and a nonuniform distribution of contact pressure on the arterial wall.
生物可吸收编织支架是治疗外周动脉疾病的一种有前景的解决方案，它在逐渐降解为生物相容性副产物之前提供临时的机械支撑。先前的研究强调了其与永久性金属支架相比机械性能较低。然而，它们在下肢动脉中的植入情况尚未得到探索，其机械性能是否足以实现有效治疗仍不确定。本研究的目的是通过计算机模拟分析评估一种聚左旋乳酸（PLLA）编织支架治疗下肢动脉的性能，并将其与镍钛（NiTi）装置进行比较。建立了PLLA支架的有限元（FE）模型，并根据实验台测试数据进行了验证。随后，通过两个台架试验（即平行板压缩试验和压接试验）的有限元模拟，将PLLA装置的机械特性与具有相同几何特征的NiTi支架进行了比较。最后，通过有限元分析对两种装置在特定患者下肢动脉中的虚拟植入过程进行了模拟，考虑了三种不同的动脉壁条件，以比较支架的治疗性能。台架试验的有限元分析证实，PLLA支架产生的力大小远低于NiTi装置。此外，虚拟植入过程表明，PLLA支架在治疗外周动脉疾病方面的短期性能有限，存在永久变形风险、管腔增益低、支架贴壁不全值高以及动脉壁上接触压力分布不均匀等问题。
