Senf B, von Sachsen S, Neugebauer R, Drossel W-G, Florek H-J, Mohr F W, Etz C D
Fraunhofer Institute for Machine Tools and Forming Technologies, Dresden, Germany.
Innovation Center Computer Assisted Surgery, Leipzig, Germany.
Med Eng Phys. 2014 Nov;36(11):1480-6. doi: 10.1016/j.medengphy.2014.07.020. Epub 2014 Aug 31.
Stent graft fixation in the vessel affects the success of endovascular aneurysm repair. Thereby the radial forces of the stent, which are dependent on several factors, play a significant role. In the presented work, a finite element sensitivity study was performed. The radial forces are 29% lower when using the hyperelastic approach for the vessel compared with linear elastic assumptions. Without the linear elastic modeled plaque, the difference increases to 35%. Modeling plaque with linear elastic material approach results in 8% higher forces than with a hyperelastic characteristic. The significant differences resulting from the investigated simplifications of the material lead to the conclusion that it is important to apply an anisotropic nonlinear approach for the vessel. The oversizing study shows that radial forces increase by 64% (0.54 N) when raising the oversize from 10 to 22%, and no further increase in force can be observed beyond these values (vessel diameter D=12 mm). Starting from an oversize of 24%, the radial force steadily decreases. The findings of the investigation show that besides the oversizing the material properties, the ring design and the vessel characteristics have an influence on radial forces.
支架移植物在血管中的固定影响血管内动脉瘤修复的成功率。因此，取决于多种因素的支架径向力起着重要作用。在本研究中，进行了有限元敏感性研究。与线性弹性假设相比，对血管采用超弹性方法时，径向力降低29%。若不采用线性弹性建模的斑块，差异增至35%。用线性弹性材料方法对斑块建模时产生的力比采用超弹性特性时高8%。材料简化研究产生的显著差异得出结论，对血管应用各向异性非线性方法很重要。超尺寸研究表明，当超尺寸从10%提高到22%时，径向力增加64%（0.54 N），超过这些值（血管直径D = 12 mm）则未观察到力的进一步增加。从超尺寸24%开始，径向力稳步下降。研究结果表明，除了超尺寸外，材料特性、环设计和血管特征也会对径向力产生影响。
