A General Method for Estimating Deformation and Forces Imposed In Vivo on Bioprosthetic Heart Valves with Flexible Annuli: In Vitro and Animal Validation Studies
Robin Shandas PhD, Max Mitchell MD, Clayton Conrad BSc, Ole Knudson RDCS, Jason Sorrell MSc, Shankar Mahalingam PhD, Miguel Fragoso MD, Lilliam Valdes-Cruz MD

Three-dimensional (3D) ultrasound imaging coupled with finite element analysis (FEA) was used to extract deformation and forces imposed in vivo on a new bioprosthetic valve with a flexible annulus. In-vitro static loading validation studies showed that spatial accuracy was preserved during translation of the 3D images into the FEA program. The method was then tested in an animal model with valves implanted in the mitral position. Results showed primary deformation of the stent along the anteroposterior axis of the mitral valve, with maximum displacements of 0.5-1.7 mm and peak reaction forces of 4.4-13.9 N. This method should prove useful for in-vivo mechanical evaluation of newly developed flexible cardiovascular prostheses.