A Computational Test-Bed to Assess Coronary Stent Implantation Mechanics Using a Population-Specific Approach

The implantation behaviour of coronary stents is of great interest to clinicians and engineers alike as in-stent restenosis (ISR) remains a critical issue with the community. ISR is hypothesized to occur for reasons that include injury to the vessel wall caused by stent placement. To reduce the incidence of ISR, improved design and testing of coronary stents is needed. This research aims to facilitate more comprehensive evaluation of stents in the design phase, by generating more realistic arterial environments and corresponding stress states than have been considered heretofore, as a step towards reducing the prevalence of ISR. Furthermore it proposes improvements to the current requirements for coronary stent computational stress analyses as set out by the Food and Drug Administration (FDA). A systematic geometric test-bed with varying levels of arterial curvature and stenosis severity is developed and used to evaluate the implantation behaviour of two stent designs using finite element analysis. A parameter study on atherosclerotic tissue behaviour is also carried out. Results are analysed using tissue damage estimates and lumen gain comparisons for each design. Results indicate that stent design does not have a major impact on lumen gain behaviour but may have an influence on the potential for tissue damage. The level of stenosis in the arterial segments is seen to have a strong impact on the results while the effects of arterial curvature appear to be design dependent.