The concept of a device for the redo transcatheter mitral valve implantation

Abstract

The aim of the investigation is the development of the heart valve prosthesis and transcatheter delivery system for the replacement of a failed mitral biological prosthesis. Materials and Methods. Calculations and construction of three-dimensional models and drawings have been performed in the Computer-Aided Design environment CATIA V5 (Dassault Systèmes, France). The process of the product shaping has been simulated by the terminal element analysis in Abaqus Software (Dassault Systèmes, France). Prototypes of the stents have been made of nitinol tubes by Angioline Interventional Device company (Novosibirsk, Russia) using a laser cutting technique with outer diameter of 7.0 mm and wall thickness 0.5 mm (Vascotube GmbH, Germany). Bioprosthetic leaflets and the cover have been cut using a laser station Melas-Cardio (Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk). The valve assemblage has been hand-made using surgical sutures 8/0. Results. The self-expanding biological prosthesis design is based on the anatomy of the left heart, considering the presence of previously implanted bioprosthesis in the mitral position. The nitinol stent of cellular structure consists of a cuff, the body and the outlet part. It is round-shaped that corresponds to the shape of a standard suture bioprostheses. One-third of the cuff adjacent to the mitralaortic contact area forms a 70-degree angle to the mitral annulus plane. In the outlet part there are three hook retainers of the previously implanted bioprosthetic leaflets. For prosthesis repositioning during implantation there are two-way (on the cuff and on hook retainers) retainers and complementary latches in the central catheter of the delivery system, they providing the connection of the valve with the delivery system in both transapical and transatrial access. The valve is provided with radiopaque markers to facilitate the positioning. Valve leaflets and the cover have been made of porcine pericardium treated with epoxy compound. The cover coats the inner surface of the stent cuff and a part of the body. Conclusion. We developed the prototype of a device for the redo transcatheter mitral valve implantation. Further preclinical testing is necessary to evaluate a safety of the medical device.