Khalaj Amnieh Sasan, Mashayekhi Mohammad, Shahnooshi Ehsan, Tavafoghi Mehdi, Mosaddegh Peiman
Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
J Biomech. 2021 Jun 9;122:110489. doi: 10.1016/j.jbiomech.2021.110489. Epub 2021 Apr 28.
Biodegradable endovascular stents have been claimed to be reliable candidates for implantation devices used in treating cardiovascular diseases since they reduce the long-term side effects on the human biological system. It is aimed in this study to investigate the effect of geometrical parameters on the degradation behavior of poly (lactic acid) stents in term of strut fracture and fragment separation. In this regard, various structural geometry of the PLA stents was simulated in a stenosed artery using finite element method. For predicting the PLA degradation, a computational model was prepared by which the influence of stents design on their radial strength and fracture was investigated. Using a laboratory-scale designed bioreactor, the PLA fibers degradation was evaluated to calibrate the material parameters and verify the simulation method. Simulation results demonstrated that the geometrical parameters, i.e., number of struts, curves radius and stent cells shape, strongly affect the degradation behavior. The results indicated that the smooth design leads to uniform degradation in the whole stent and decreases the danger of stent fragments separation. It was shown that the maximum degradation rate of the stents with rounded curves was one-third of the models with sharp corners.
可生物降解的血管内支架被认为是治疗心血管疾病的植入装置的可靠候选者，因为它们减少了对人体生物系统的长期副作用。本研究旨在从支柱断裂和碎片分离的角度研究几何参数对聚乳酸支架降解行为的影响。在这方面，使用有限元方法在狭窄动脉中模拟了聚乳酸支架的各种结构几何形状。为了预测聚乳酸的降解，制备了一个计算模型，通过该模型研究了支架设计对其径向强度和断裂的影响。使用实验室规模设计的生物反应器，评估聚乳酸纤维的降解以校准材料参数并验证模拟方法。模拟结果表明，几何参数，即支柱数量、曲线半径和支架单元形状，对降解行为有强烈影响。结果表明，光滑的设计导致整个支架均匀降解，并降低了支架碎片分离的风险。结果表明，带有圆形曲线的支架的最大降解率是带有尖角的模型的三分之一。
