Textile Materials and Processes Research Unit MPTex, ENIM, University of Monastir, Monastir, Tunisia.
Service de Chirurgie Vasculaire - GEPROVAS, Hôpitaux Universitaires de Strasbourg, 67000, Strasbourg, France.
J Mech Behav Biomed Mater. 2019 Oct;98:131-136. doi: 10.1016/j.jmbbm.2019.06.018. Epub 2019 Jun 18.
Over the last decades, stents have been largely used to treat vascular diseases such as coronary artery or peripheral vessel stenosis. Among the solutions which are commercially available to treat vascular stenosis, metallic stents represent the gold standard. However, issues such as restenosis, corrosion and fractures have been reported with these devices and are especially due to the material which is used. Braided polymeric stents could present an alternative to replace metallic stents especially in peripheral vessels where flexibility is required. Among polymeric materials, polyethylene terephthalate (PET), could be a good candidate as its biocompatibility has already been widely proven especially in the field of cardiovascular applications. Moreover, braided devices have been already used for the stenting of peripheral zones, providing locally outstanding flexibility due to the discontinuity of these structures. The goal of this work was to evaluate the radial strength and the recovery performances of polymeric braided stents made from PET monofilaments. In particular, the behavior of these stents under repeated cyclic radial compression loading was assessed and compared to results obtained with a metallic braided stent of same diameter. Results show that polymeric braided stents provide 100% elastic recovery after 20% diameter compression over 2000 repetitive loading cycles. However, radial strength goes slightly down with cycling, which points out that friction occurs in the braid. It comes out from the study that a braided polymer stent shows suitable mechanical behavior compared to a metallic stent over cyclic loading up to 2000 cycles. Moreover, it is shown that the mechanical behavior of these stents depend highly on the braid angle.
在过去的几十年中，支架已被广泛用于治疗血管疾病，如冠状动脉或外周血管狭窄。在用于治疗血管狭窄的商业解决方案中，金属支架是金标准。然而，这些设备存在再狭窄、腐蚀和断裂等问题，主要是由于所使用的材料造成的。编织聚合物支架可以替代金属支架，特别是在外周血管中需要柔韧性的情况下。在聚合物材料中，聚对苯二甲酸乙二醇酯（PET）可能是一个很好的候选材料，因为其生物相容性已经得到广泛证明，尤其是在心血管应用领域。此外，编织设备已经用于外周区域的支架，由于这些结构的不连续性，提供了局部出色的柔韧性。本工作的目的是评估由 PET 单丝制成的聚合物编织支架的径向强度和恢复性能。特别是，评估了这些支架在重复循环径向压缩载荷下的行为，并与相同直径的金属编织支架的结果进行了比较。结果表明，聚合物编织支架在 20%直径压缩下可提供 100%的弹性恢复，经过 2000 次重复加载循环。然而，随着循环的进行，径向强度略有下降，这表明编织过程中存在摩擦力。研究表明，与金属支架相比，编织聚合物支架在 2000 次循环的循环加载下具有合适的机械性能。此外，还表明这些支架的机械性能高度依赖于编织角度。
