The physical properties of the
stent surface influence the effectiveness of
vascular disease treatment after
stent deployment. During the expanding process, the
stent acquires high-level deformation that could alter either its microstructure or the magnitude of surface roughness. This paper constructed a finite
element simulation to observe the changes in surface roughness during the stenting process. Structural transient dynamic analysis was performed using ANSYS, to identify the deformation after the
stent is placed in a blood vessel. Two types of bare
metal stents are studied: a Palmaz type and a Sinusoidal type. The relationship between plaque length and the changes in surface roughness was investigated by utilizing three different length of plaque; plaque length longer than the
stent, shorter than the
stent and the same length as the
stent. In order to reduce computational time, 3D cyclical and translational symmetry was implemented into the FE model. The material models used was defined as a multilinear isotropic for
stent and hyperelastic for the balloon, plaque and vessel wall. The correlation between the
plastic deformation and the changes in surface roughness was obtained by intermittent pure tensile test using specimen whose chemical composition was similar to that of actual
stent material. As the
plastic strain is achieved from FE simulation, the surface roughness can be assessed thoroughly. The study found that the plaque size relative to
stent length significantly influenced the critical changes in surface roughness. It was found that the length of
stent which is equal to the plaque length was preferable due to the fact that it generated only moderate change in surface roughness. This effect was less influential to the Sinusoidal
stent.