Mechanical characterization of aortic valve tissues using an inverse analysis approach

Abstract

International audienceThe use of numerical simulation to investigate heart and valvular mechanics is becoming increasingly popular. In particular, finite element analysis is often used to support the operation planning procedure as well as the design of new prostheses with mechanical properties as close as possible to those of natural tissues and an even better biocompatibility. With one of the highest prevalence of cardiovascular degenerative diseases [1], aortic valves (AV) have been widely studied during the last decades.The elastic [2] and time-dependent [3] behaviors of the AV leaflets under physiological biaxial loading states have been previously investigated in the literature over a wide range of loading conditions.. As most soft tissues, AV has an oriented network of collagen fibers embedded in an elastin matrix, which is responsible for their hyperelastic and anisotropic behaviors. Accordingly, non-linear transverse isotropic constitutive equations are often used assuming a macroscopically-identifiable preferred fiber direction.In this study a new method is proposed in order to estimate relevant material and structural properties of AV while reducing at the same time the number of complex and time-consuming experiments. An inverse analysis procedure based on the finite element computation of planar biaxial tensile tests was used to set-up a reduced protocol. This protocol was then experimentally reproduced to identify real material parameters. The obtained material parameters will be later used to model heart valve tissues

The effect of the fibrocalcific pathological process on aortic valve stenosis in female patients: a finite element study

“…It is based on a confocal microscopy image of the collagen fibers [25]. This architecture is also supported by the data taken from [4,18,26,27,37,[42][43][44][45][46][47][48][49][50]. The fibers network in type II was denser in the belly region, and the fibers were oriented more straight in the lower belly and in a cross configuration in the upper belly compared to the type I architecture.…”