Computational Modeling to Predict Fatigue Behavior of NiTi Stents: What Do We Need?

Journal of Functional Biomaterials

Elena Dordoni¹  Lorenza Petrini²  Wei Wu¹  Francesco Migliavacca¹  Gabriele Dubini¹  Giancarlo Pennati¹ 

[1] Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering ‘Giulio Natta’, Politecnico di Milano, Milan 20133, Italy; E-Mails:;Department of Civil and Environmental Engineering, Politecnico di Milano, Milan 20133, Italy

关键词: peripheral arterial diseases;    shape memory alloys;    cardiovascular devices;    fatigue failure;    finite element analyses;   

DOI  :  10.3390/jfb6020299

来源: mdpi

【 摘 要 】

NiTi (nickel-titanium) stents are nowadays commonly used for the percutaneous treatment of peripheral arterial disease. However, their effectiveness is still debated in the clinical field. In fact a peculiar cyclic biomechanical environment is created before and after stent implantation, with the risk of device fatigue failure. An accurate study of the device fatigue behavior is of primary importance to ensure a successful stenting procedure. Regulatory authorities recognize the possibility of performing computational analyses instead of experimental tests for the assessment of medical devices. However, confidence in numerical methods is only possible after verification and validation of the models used. For the case of NiTi stents, mechanical properties are strongly dependent on the device dimensions and the whole treatments undergone during manufacturing process. Hence, special attention should be paid to the accuracy of the description of the device geometry and the material properties implementation into the numerical code, as well as to the definition of the fatigue limit. In this paper, a path for setting up an effective numerical model for NiTi stent fatigue assessment is proposed and the results of its application in a specific case study are illustrated.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.