Klaas Loger1, Saskia Pokorny1,2, Tim Schaller1,2, Irma Haben1, Derk Frank3, Georg Lutter1. 1. Department of Cardiovascular Surgery, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel, Germany. 2. Institute of Biomechanics, Technical University Hamburg-Harburg, Hamburg, Germany. 3. Department of Cardiology and Angiology, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel, Germany.
Abstract
OBJECTIVES: In this study, results of a functional in vitro study of 2 newly developed valved stents for transcatheter mitral valve implantation are presented. METHODS: Two novel stent designs, an oval-shaped and a D-shaped stent with a strut fixation system were developed. The fixation force of the novel stents were tested in vitro in porcine hearts with a tensile test set-up. In further experiments, the stents were equipped with a circular valved stent, and the valve performances were investigated in a pulsatile heart valve tester. RESULTS: Sufficient mean stent fixation forces in the range of 24.2 ± 0.9 N to 28.6 ± 1.9 N were measured for the different stent models. The novel valved stents showed good performance in an in vitro pulsatile heart valve tester. A sufficient opening area and low opening pressures were measured for all tested mitral valved stents. Compared with an established reference valve, the D-shaped stent and the oval-shaped valved stent showed a lower systolic transvalvular pressure gradient, which indicates slightly greater extent of valvular leakage of the closed valved stents. However, the mitral nitinol valved stents demonstrated adequate durability. CONCLUSIONS: This study indicates a sufficient annular fixation force of the tested transcatheter mitral valve implantation valved stent prototypes. Therefore, these mitral valved stents demonstrate a new type of mitral valved stent design.
OBJECTIVES: In this study, results of a functional in vitro study of 2 newly developed valved stents for transcatheter mitral valve implantation are presented. METHODS: Two novel stent designs, an oval-shaped and a D-shaped stent with a strut fixation system were developed. The fixation force of the novel stents were tested in vitro in porcine hearts with a tensile test set-up. In further experiments, the stents were equipped with a circular valved stent, and the valve performances were investigated in a pulsatile heart valve tester. RESULTS: Sufficient mean stent fixation forces in the range of 24.2 ± 0.9 N to 28.6 ± 1.9 N were measured for the different stent models. The novel valved stents showed good performance in an in vitro pulsatile heart valve tester. A sufficient opening area and low opening pressures were measured for all tested mitral valved stents. Compared with an established reference valve, the D-shaped stent and the oval-shaped valved stent showed a lower systolic transvalvular pressure gradient, which indicates slightly greater extent of valvular leakage of the closed valved stents. However, the mitral nitinol valved stents demonstrated adequate durability. CONCLUSIONS: This study indicates a sufficient annular fixation force of the tested transcatheter mitral valve implantation valved stent prototypes. Therefore, these mitral valved stents demonstrate a new type of mitral valved stent design.
Authors: Eric L Pierce; Vahid Sadri; Beatrice Ncho; Keshav Kohli; Siddhi Shah; Ajit P Yoganathan Journal: Ann Biomed Eng Date: 2018-10-17 Impact factor: 3.934