Effects of plaque lengths on stent surface roughness

Area of Science:

• Biomedical Engineering
• Materials Science
• Computational Mechanics

Background:

• Stent surface properties critically affect vascular disease treatment outcomes.
• Stent deployment involves significant deformation, potentially altering surface microstructure and roughness.
• Understanding these changes is crucial for optimizing stent design and performance.

Purpose of the Study:

• To investigate the influence of stent deployment on surface roughness using finite element analysis (FEA).
• To evaluate how plaque length relative to stent length affects surface roughness changes.
• To compare the surface roughness behavior of Palmaz and Sinusoidal bare metal stents.

Main Methods:

• Finite element simulation using ANSYS with structural transient dynamic analysis.
• Modeling of stent, balloon, plaque, and vessel wall using multilinear isotropic and hyperelastic material models.
• Implementation of 3D cyclical and translational symmetry to optimize computational efficiency.
• Correlation of plastic deformation with surface roughness via tensile testing of stent material specimens.

Main Results:

• Plaque size relative to stent length significantly impacts critical changes in surface roughness.
• Stents with length equal to plaque length exhibited moderate changes in surface roughness.
• The Sinusoidal stent design demonstrated less susceptibility to surface roughness alterations compared to the Palmaz type.

Conclusions:

• Optimizing stent length to match plaque length is a key strategy to minimize detrimental surface roughness changes.
• The Sinusoidal stent design offers potential advantages in maintaining surface integrity during deployment.
• FEA provides a valuable tool for predicting and mitigating surface modifications in vascular stents.