Methodology for the study by means of numerical simulation of the adaptation of the stent of an aortic valve prosthesis to the area of implantation

Abstract

This paper presents a methodology for the numerical simulation study of the adaptability of the support structure (stent) of the aortic valve prostheses used in the transcatheter aortic valve implantation (TAVI) procedure to the particular anatomy of a specific patient. The TAVI procedure is a common practice in patients with degenerative aortic valve disease such as valve stenosis who cannot undergo conventional methods of valve replacement due to the high risk of the operation. During this process, the valve prosthesis is introduced via a catheter to the implantation site. Therefore, the success of the intervention, as well as the durability and effectiveness of the prosthesis, depend to a large extent on the adaptation of the stent to the aortic cavity in which it is placed. A defective fit can lead to severe reductions in the device's lifespan and, in addition, to leaks that will result in backflow of blood into the ventricle. In order to study the adaptation of the support structure, a procedure is established by which, based on numerical simulation using finite elements (FEM), aspects such as the contact areas between the two and the stress and deformation in these components can be evaluated. For this purpose, the anatomy of the aortic root of each patient is extracted by means of medical imaging and a finite element model is constructed with it. This model is complemented with the previously validated finite element model generated for the stent. A complete model is then generated that evaluates the interaction between the artery and the stent and allows evaluation of aspects such as the contact areas between the two and the stress and deformation in these components