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Objective Transcatheter aortic valve impantation(TAVI)  rapidly developed in recent decade, however, paravalvular aortic regurgitation (AR) , as a complication,  significantly influences the morbidity and mortality after TAVI. In this study, it was evaluated that effect of stent design on the paravalvular regurgitation of transcatheter aortic valve implantation based on numerical simulations. Methods Three self-expanding transcatheter aortic valve stent designs model were developed base on the commercial products. Three stents had the same inflow end but different outflow end. Stent1 had more struts on the outflow end which is similar first generation stent. Stent 2 had a sparser outflow end. Stent 3 had most sparse struts on the outflow end.  They were radial compressed and implanted into the representative calcified human aortic root models. Then the effect of different stent design on the aortic root stresses, stent deformations and the gaps between the stent and aortic root was analyzed in order to understand the relationship to paravalvular regurgitation. Results The same inflow end and the different degree of sparse outflow end was found in the three stent, which induced the different stent deformation, a different stress on the calcified plaques and aortic root, and a different gap between the stent and aortic root.  Both an excessively dense or sparse outflow end design resulted in a lager stent deformation, a higher stress calcified plaques and aortic root, and a lager gap, which led to more serious paravalvular regurgitation. Stent 2 had a moderate sparse outflow end obtained the smallest deformation, the lowest stress, and the smallest gaps, indicate this design will lead to a low risk of paravalvular regurgitation. Conclusions An excessively dense or a sparse outflow end would result in a larger stent deformation indexes, a higher stress calcified plaques and aortic root, and a lager gap, and led to serious paravalvular regurgitation.  This study provided the guidance for design of transcatheter aortic valve. And it would help predict the clinical outcome after implanted.

Transcatheter aortic valve implantation; Finite element analysis; Stent design; Paravalvular regurgitation