Transcatheter mitral valve repair devices - in vitro studies on the influence of device-width on mitral regurgitation

Autor: Ott Robert, Kaule Sebastian, Großmann Swen, Stiehm Michael, Schmitz Klaus-Peter, Siewert Stefan, Öner Alper Ö, Ince Hüseyin, Grabow Niels
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Current Directions in Biomedical Engineering, Vol 6, Iss 3, Pp 217-220 (2020)
Druh dokumentu: article
ISSN: 2364-5504
2020-3055
DOI: 10.1515/cdbme-2020-3055
Popis: Mitral regurgitation (MR) is the most prevalent valvulopathy in the USA and the second most prevalent valvulopathy in Europe. Despite excellent clinical results of surgical mitral valve repair (SMVR), transcatheter-based mitral valve repair (MVR) procedures emerged as a feasible treatment option for surgically inoperable or high-risk patients suffering from clinically relevant MR. The current study investigates the impact of device-induced coaptationwidth on the hydrodynamic performance of insufficient mitral valves (MV) during left ventricular (LV) systole. A non-calcified, pathological MV model (MVM) featuring a D-shaped MV annulus with an area of 7.6 cm2 and a flail gap in the A2-P2 region was employed in an experimental setup. Pressure gradient-volumetric flow rate (Δp-Q) relations were investigated for steady-state backward flow with transvalvular pressure gradients ranging from (0.75 ≤ Δp ≤ 177.36) mmHg. Glycerol-water mixture (36 % (v/v) glycerol in water) at 37 °C with a density of (1 098.2 ± 1.3) kg·m-3 and a dynamic viscosity of 3.5 mPa∙s was used as circulatory fluid. In order to determine the impact of the width of transcatheter MVR devices during LV-systole Δp-Q relations were investigated for three MVM-configurations: (i) MVM without MVR device, (ii) MVM with one MVR device and (iii) MVM with two MVR devices implanted in the A2-P2 region. The MVR devices were manufactured from steel sheets with a thickness of 0.2 mm and feature arm lengths of 9.0 mm and a width of 5.0 mm. The conducted investigations show that the implantation of MVR devices in the A2-P2 region prevents the manifestation of an A2-P2 flail gap and thereby effectively reduces the retrograde blood flow during the LV-systole by 13 % with one MVR device and 27 % with two MVR devices implanted. Thus, the application of two MVR devices with a combined device-induced width of 10 mm results in a better MR reduction than the implantation of one MVR device with a device-induced width of 5 mm.
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