Comparison of flow dynamics of Perimount Magna and Magna Ease aortic valve prostheses

Abstract

The aim of the present study was to evaluate and compare the in vitro and flow dynamics of the Magna (MB) and the Magna Ease aortic valve bioprosthesis (MEB) within the ascending aorta. A 2D-particle-image-velocimetry (2D-PIV) study was performed to compare the flow dynamics induced by each pericardial Carpentier-Edwards Magna and Magna Ease aortic valve prosthesis in the aortic flow field directly behind the valve. Both prostheses (diameter 23 mm) were placed inside an artificial aorta under pulsatile flow conditions (70 Hz and 70 ml stroke volume). The flow field was evaluated according to velocity, shear strength, and vorticity. Both prostheses showed a jet flow type profile with a maximum velocity of 0.97±0.09 m/s for MB and 0.83±1.8 m/s for MEB. Flow fields of both valves were similar in acceleration, peak flow deceleration and leakage phase. Maximum shear strength was 20,285±11,774 l/s2 for MB and 17,006±8453 l/s2 for MEB. Vorticity was nearly similar for counterclockwise and clockwise rotation in both prostheses, but slightly higher with MB (251±41 l/s and -250±39 l/s vs. 225±48 l/s and -232±48 l/s). The point-of-interest (POI)-analysis revealed a higher velocity for left-sided aortic wall compared to right-sided at MB (0.12±0.09 m/s vs. 0.18±0.10 m/s, p<0.001), but was consistent at MEB (0.09±0.05 m/s vs. 0.08±0.04 m/s, p=0.508), respectively. Velocity, shear strength and vorticity in an in vitro test set-up are lower with MEB compared to MB, thus resulting in improved flow dynamics with a similar flow field, which might have a positive influence on blood rheology and potential valve degeneration.

Transcatheter aortic valves produce unphysiological flows which may contribute to thromboembolic events: An in-vitro study

“…A number of pure liquids and liquid solutions have been used in other studies to simulate blood, including pure water (Falahatpisheh and Kheradvar, 2012, Van Steenhoven and Van Dongen, 1979, Wendt et al, 2012), saline solution (Akutsu et al, 2008, Bottio et al, 2004, Ducci et al, 2013, Grigioni et al, 2000) and a water–glycerol solution (Azadani et al, 2009, Bullen and Rogers, 1968, Grigioni et al, 2003, Guivier-Curien et al, 2009, Kadem et al, 2005, Kadem et al, 2006, Lim et al, 1994, Lim et al, 1998, Stühle et al, 2011, Yoganathan et al, 1986). When using a laser-based technique such as PIV, it is essential to minimise the optical distortion due to the refraction occurring at the interface between different media in complex geometries.…”

The Fluid Dynamical Performance of the Carpentier-Edwards PERIMOUNT Magna Ease Prosthesis

“…The present study intended to continue our research work that was already dealing with the comparison of the Carpentier-Edwards PERIMOUNT Magna and the Carpentier-Edwards PERIMOUNT Magna Ease bioprostheses [ 12 , 13 ].…”

“…As we used water instead of a water-saline or glycerin solution as blood similar test fluid [ 22 ] the validity of the absolute values of the collected data might be limited. Although previous studies showed that for the qualitative and relative comparison the use of water is acceptable [ 12 , 13 ].…”

“…The test setup consisted of two modules, a flow channel and a PIV (particle image velocimetry) system. The flow channel has already been described in previous studies [ 12 – 14 ]. The present flow channel was updated by a more physiological aortic model made of transparent silicon instead of PMMA (polymethylmethacrylate) and a modified simulation of peripheral resistance.…”

The Effects of Positioning of Transcatheter Aortic Valves on Fluid Dynamics of the Aortic Root

“…Digital Particle Image Velocimetry (DPIV) is a robust and validated technique for imaging, assessing and quantifying cardiac fluid dynamics in vitro. 8-11 The high spatial and temporal resolution of DPIV allows for accurate assessment of cardiovascular devices such as heart valves under different conditions. 12-15 To utilize DPIV for cardiovascular device assessment, precise replication of cardiac flow fields in vitro is essential.…”