Finite Element Analysis of Evolut Transcatheter Heart Valves: Effects of Aortic Geometries and Valve Sizes on Post-TAVI Wall Stresses and Deformations

Figure 1. Aorta geometry generation (a) Patient-specific CT images, (b) 3D geometry segmentation using 3D Slicer software, and (c) final volume and surface geometries for FEA.

Figure 2. (a) The parametric native valve geometry design: Geometrical parameters (mm) of the native leaflets taken from the literature [28] are indicated with the red color, and the generated parametric native leaflets in different annulus diameters (14 mm, 15 mm, 16 mm, and 17 mm, respectively). (b) The placement process of the parametric native valve geometry into the aortic root.

Figure 3. The 23 mm, 26 mm, 29 mm, and 34 mm Medtronic Evolut-R TAV design steps. (a) Surface spline created from the calibrated catalog image using the device dimensions, (b) stent, (c) prosthetic leaflets, (d) skirt, and (e) final and full geometries of the 23 mm, 26 mm, 29 mm, and 34 mm Medtronic Evolut-R devices.

Figure 4. Mesh convergence analysis graphs for prosthetic leaflets. (a) U1 displacement versus time plot for the upper midpoint of the prosthetic leaflet at different element sizes, (b) internal energy (IE) and kinetic energy (KE) versus time plot for the prosthetic leaflet at different element sizes, and (c) the percentage of IE over KE for the prosthetic leaflet at different element sizes. (d) The illustration of the meshed aorta, native leaflets, stent, skirt, and prosthetic leaflet geometries.

Figure 5. Material behaviors for the aortic root, native leaflets, and TAV device (color-coded).

Figure 6. FEA stent contact area results for all examined cases, compared to pre-crimped TAV stent outer areas seen on the left bars.

Figure 7. Bar chart representation of the FEA results for 26 mm TAV implanted cases; 23 mm TAV and 29 mm TAV implantation were also simulated for comparison.

Figure 8. Graphical presentation of FEA results for 26 mm TAV implanted cases. The 23 mm TAV and 29 mm TAV implantation were also simulated for comparison for each case. Actual valve sizes for the implants are indicated in bold and designated with “-R”. Contour plots for all 26 mm cases are provided in Supplementary Materials.

Figure 9. Bar chart representation of the FEA results for 29 mm TAV implanted cases. 26 mm TAV and 34 mm TAV implantation were also simulated for comparison.

Figure 10. Graphical representation of FEA results for 29 mm TAV implanted cases. The 26 mm TAV and 34 mm TAV implantations were also simulated for a comparative analysis in each case. Actual valve sizes for the implants are indicated in bold and designated with “-R”. Contour plots for all 29 mm cases are provided in Supplementary Materials.

Figure 11. Bar chart representation of the FEA results for 34 mm TAV implanted cases. The 29 mm TAV implantation was also simulated for comparison.

Figure 12. Graphical representation of FEA results for 34 mm TAV implanted cases. The 29 mm TAV implantation was also simulated for a comparative analysis in each case. Actual valve sizes for the implants are indicated in bold and designated with “-R”. Contour plots for all 34 mm cases are provided in Supplementary Materials.