A detailed stent life-cycle simulation accurately predicted the transient stent expansion, dogboning ratio, and final dimensions of folded balloons and crimped/expanded stents with less than 2% deviation from experimental measurements.
Detailed stent life-cycle simulation, including balloon folding and crimping, is essential for accurate stent expansion analysis and optimization compared to simplified displacement-controlled approaches.
In-stent restenosis remains a major problem of arteriosclerosis treatment by stenting. Expansion-optimized stents could reduce this problem. With numerical simulations, stent designs/ expansion behaviours can be effectively analyzed. For reasons of efficiency, simplified models of balloon-expandable stents are often used, but their accuracy must be challenged due to insufficient experimental validation. In this work, a realistic stent life-cycle simulation has been performed including balloon folding, stent crimping and free expansion of the balloon-stent-system. The successful simulation and validation of two stent designs with homogenous and heterogeneous stent stiffness and an asymmetrically positioned stent on the balloon catheter confirm the universal applicability of the simulation approach. Dogboning ratio, as well as the final dimensions of the folded balloon, the crimped and expanded stent, correspond well to the experimental dimensions with only slight deviations. In contrast to the detailed stent life-cycle simulation, a displacement-controlled simulation can not predict the transient stent expansion, but is suitable to reproduce the final expanded stent shape and the associated stress states. The detailed stent life-cycle simulation is thus essential for stent expansion analysis/optimization, whereas for reasons of computational efficiency, the displacement-controlled approach can be considered in the context of pure stress analysis.
Wiesent et al. (Fri,) conducted a other in In-stent restenosis. Detailed stent life-cycle simulation vs. Displacement-controlled simulation and experimental measurements was evaluated on Stent dimensions (crimped and expanded) and dogboning ratio. A detailed stent life-cycle simulation accurately predicted the transient stent expansion, dogboning ratio, and final dimensions of folded balloons and crimped/expanded stents with less than 2% deviation from experimental measurements.