A computational study of stent performance by considering vessel anisotropy and residual stresses

Abstract

Finite element simulations of stent deployment were carried out by considering the intrinsic anisotropic behaviour, described by a Holzapfel-Gasser-Ogden (HGO) hyperelastic anisotropic model, of individual artery layers. The model parameters were calibrated against the experimental stress-stretch responses in both circumferential and longitudinal directions. The results showed that stent expansion, system recoiling and stresses in the artery layers were greatly affected by vessel anisotropy. Following deployment, deformation of the stent was also modelled by applying relevant biomechanical forces, i.e. in-plane bending and radial compression, to the stent-artery system, for which the residual stresses generated during deployment were particularly accounted for. Residual stresses were found to have a significant influence on the deformation of the system, resulting in a re-distribution of stresses and a change of the system flexibility. The results were also utilised to interpret the mechanical performance of stent after deployment.

Computational analysis of mechanical stress–strain interaction of a bioresorbable scaffold with blood vessel

“…The HGO model (Holzapfel et al, 2000) was used to describe the anisotropic constitutive behaviour of arterial layers (reinforced with two families of fibre). The HGO model parameters for the three layers were calibrated against the experimental data in Holzapfel et al (2005) and given in Schiavone and Zhao (2016).…”

“…This indicates that the stent structure has accumulated significant plastic strain during crimping before the inflation process begins. These residual stresses are believed to affect the nature of stent deformation during the subsequent expansion process (Schiavone and Zhao, 2016).…”

The Crimping and Expanding Performance of Self-Expanding Polymeric Bioresorbable Stents: Experimental and Computational Investigation

“…A 32-bobbin braiding machine was used to fabricate prototype composite stents [19] in the Biomedical Textile Materials Research Laboratory of Donghua University, Shanghai, China. The cBYs were braided with PPDO monofilaments to form composite polymeric bioresorbable stents (cPBRSs).…”

“…The main objective of this study was to further mechanical research of self-expanding PBRSs under crimping and expanding processes, as well as to elucidate the relationship between their design and stability. In our former study, we developed composite self-expanding stents that incorporate poly( p -dioxanone) (PPDO) monofilaments and Poly(ε-caprolactone) (PCL) multifilaments based on braiding technology [19], which are aimed at congenital heart disease. We provided an experimental method for crimping and expanding evaluation of polymer prototypes in vitro.…”

A Computational Study of Mechanical Performance of Bioresorbable Polymeric Stents with Design Variations

“…For hypocellular plaque, the constitutive behaviour was defined in the form of first-order hyperelastic Ogden strain energy potential 30 , and the material parameters were calibrated against experimental data 31 . Further details, regarding the model parameters and comparison between model simulations and experimental data, can be found in our previous study 6,32 . Table 2, Parameter values of the anisotropic hyperelastic Gasser-Ogden-Holzapfel model 6 .…”