Detailed Stress Analysis of Edwards-SAPIEN and Medtronic CoreValve Devices. Is Leaflet Stress Comparable to Surgical Carpentier-Edwards PERIMOUNT Magna Bioprosthesis?

Objective: Transcatheter aortic valves (TAVs) are prone to structural valve deterioration resulting in limited long-term durability. However, data regarding long-term durability of TAVs are limited and there might exist a difference in long-term durability of different TAVs. The aim of this study was to perform a side-by-side comparison of leaflet stress distribution of three most commonly used transcatheter and surgical bioprostheses. Methods: Using integrated experimental methods (i.e., digital image correlation measurements and hemodynamic testing) and numerical methods (i.e. finite element modeling and material optimization), three-dimensional anisotropic mechanical properties of leaflets of 26-mm Edwards SAPIEN 3 and 26-mm Medtronic CoreValve were characterized and compared to that of a 25-mm Carpentier-Edwards (CE) PERIMOUNT Magna. Maximum in-plane principal stress distribution of the leaflets were obtained and compared during systole and diastole. Results: High stress regions were primarily observed in the fixed boundary edges of the three bioprostheses in the systole. During diastole, high stress regions were observed close to the commissures in the Magna and SAPIEN 3 (Figure 1). For CoreValve, however, the maximum stress values were observed in the lower leaflet belly region. In the diastole, the peak of maximum in-plane principal stress was 0.98, 0.96 and 2.95 MPa for the CE PERIMOUNT Magna, CoreValve, and SAPIEN 3, respectively. Conclusions: The present work presents a reliable approach to compare leaflet stress distribution among different bioprostheses. Our results indicated the CoreValve had the lowest peak stress value at the identical pressure value during diastole compared to the PERIMOUNT Magna and SAPIEN 3. Considering the leaflet stress distributions, there might be a difference in the long-term durability of different TAVs.