title: Effects of Leaflet Design on Transvalvular Gradients of Bioprosthetic Heart Valves.
abstract: Bioprosthetic aortic valves (BAVs) are becoming the prostheses of choice in heart valve replacement. The objective of this paper is to assess the effects of leaflet geometry on the mechanics and hemodynamics of BAVs in a fluid structure interaction model. The curvature and angle of leaflets were varied in 10 case studies whereby the following design parameters were altered: a circular arch, a line, and a parabola for the radial curvature, and a circular arch, a spline, and a parabola for the circumferential curvature. Six different leaflet angles (representative of the inclination of the leaflets toward the surrounding aortic wall) were analyzed. The 3-dimensional geometry of the models were created using SolidWorks, Pointwise was used for meshing, and Comsol Multiphysics was used for implicit finite element calculations. Realistic loading was enforced by considering the time-dependent strongly-coupled interaction between blood flow and leaflets. Higher mean pressure gradients as well as von Mises stresses were obtained with a parabolic or circular curvature for radial curvature or a parabolic or spline curvature for the circumferential curvature. A smaller leaflet angle was associated with a lower pressure gradient, and, a lower von Mises stress. The leaflet curvature and angle noticeably affected the speed of valve opening, and closing. When a parabola was used for circumferential or radial curvature, leaflets displacements were asymmetric, and they opened and closed more slowly. A circular circumferential leaflet curvature, a linear leaflet radial curvature, and leaflet inclination toward the surrounding aortic wall were associated with superior BAVs mechanics.
authors: Libin Cardiovascular Institute of Alberta, Health Research Innovation Centre (HRIC), University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
authors: Yaghoub
authors: Y
authors: Dabiri
authors: Schulich School of Engineering, University of Calgary, Calgary, Canada.
authors: Janet
authors: J
authors: Ronsky
authors: Libin Cardiovascular Institute of Alberta, Health Research Innovation Centre (HRIC), University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
authors: Imtiaz
authors: I
authors: Ali
authors: Cummings School of Medicine Health Sciences, University of Calgary, Calgary, Canada.
authors: Ameen
authors: A
authors: Basha
authors: Nanotechnology Engineering, University of Waterloo, Waterloo, Canada.
authors: Alisha
authors: A
authors: Bhanji
authors: Libin Cardiovascular Institute of Alberta, Health Research Innovation Centre (HRIC), University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada. kishnarine@gmail.com.
authors: Kishan
authors: K
authors: Narine
mesh_terms: D001705:Bioprosthesis; D017076:Computer-Aided Design; D006350:Heart Valve Prosthesis; D006801:Humans; D008955:Models, Cardiovascular; D011474:Prosthesis Design / Q000379:methods*
keywords: Design; Fluid structure interaction; Numerical modeling; Prosthetic aortic valve