DEVELOPMENT OF A NOVEL MODULAR HEART VALVE PROSTHESIS FOR THE PULMONARY POSITION

Background: Due to the anatomical variance of the right ventricular outflow tract and resulting difficult anchoring, transcatheter pulmonary valve implantation (TPVI) has received little attention. In order to create anatomically fit, patient-customized prostheses, a modular TPVI prosthesis consisting of standardized connectable elements was developed. Methods: Anatomical studies were performed to define the dimensions of the elements needed to provide satisfactory anatomical adaptation. Finite element analyses (FEA) were performed using Abaqus/CAE (Simulia, USA) to iteratively optimize the mechanical properties. The considered conditions include expansion from a 10 mm nitinol tube during fabrication, as well as the crimping and deployment processes. Stent-leaflet interaction was assessed, considering the physiological pressure curve in the RVOT during 3 cardiac cycles. The designs of the stent frame elements and leaflets were optimized until the strains and stresses met acceptable values. Results: Maximum stresses were 800 MPa for crimping and deployment simulation at 37[degrees]C. The design of the central valve bearing element considers the need for leaflet integration and their dynamics. Prototypes were manufactured by laser cutting and assembled. Conclusions: Using the approach of iterative stent frame optimization, satisfactory designs of all elements needed to assemble modular customizable TPVI prostheses were found.