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.

Background: Aortic valve replacement (AVR) using extracorporeal circulation is currently the treatment of choice for symptomatic aortic stenosis. However, patients with multiple high-risk comorbid conditions may benefit from reduced ECC time by a simplified and faster resection in conjunction with quick sutureless valve implantation. Methods: A prototype of a new minimally invasive aortic valve resection tool equipped with rotating and foldable Nitinol cutting edges was designed. Commercially available aortic valve bioprostheses were artificially calcified (group 1: moderate calcified, n = 8, group 2: severely calcified, n = 8). In vitro resection was performed using a 21 mm cutting blade. Resection time (RT), maximum turning moment (MTM) and number of required rotations (NR) were measured. Furthermore, particle generation during the process of cutting was obtained and quantified. Results: Aortic valve cutting could be obtained without any complications in all cases. Cutting process resulted in a RTof 15.5 AE 3 s in group 1 compared to 34.9 AE 15 s in group 2 ( p = 0.005), MTM was 3 AE 0.6 N m in group 1 compared to 3.5 AE 0.6 N m in group 2 ( p = 0.068) and NR were 30.6 AE 2.3 in group 1 compared to 48.1 AE 15.5 in group 2 ( p = 0.007). Particle generation was 1.77 AE 0.17 g in group 1 compared to 1.41 AE 0.44 g in group 2 ( p = 0.047). Conclusions: These first in vitro results confirm feasibility and accelerated aortic valve resection within 30 s. This new concept holds promise for very fast AVR in combination with insertion of sutureless aortic valve prosthesis, targeting for ischemic times less than 10 min in the open heart situation. Finally, resection and percutaneous AVR within 1 min in the beating heart situation is envisioned. #

Objective Currently, sutureless heart valves (SHV) reveal good clinical results during aortic valve replacement. The aim of this study was to evaluate the fluid dynamics of the ATS 3F Enable SHV in the ascending aorta and their influence on the aortic wall in an in vitro setup. Methods A two-dimensional particle image velocimetry study with an image rate of 15 Hz was conducted to evaluate the fluid dynamics of the SHV in the aortic flow field. The prosthesis (diameter, 23 mm) was placed inside a silicone mock aorta under pulsatile flow conditions. Velocities, vorticity, and strain rate were obtained and calculated with a fixed frequency (70 Hz) at constant stroke volume (70 mL). Results 3F Enable showed a jet flow type profile with a maximum velocity of 1.01 ± 0.13 m/s during peak flow phase (PFP). The jet flow was surrounded by ambilateral vortices with a slightly higher percentage of clockwise than counterclockwise vorticity (377 ± 57/s vs 389 ± 76/s), strain rate (370 ± 79/s for elongation vs — 370 ± 102/s for contraction) was nearly similar. The point-of-interest analysis revealed a higher velocity for bottom compared with upper aortic wall (0.28 ± 0.07 m/s vs 0.31 ± 0.06 m/s, P = 0.024). All values were lower during acceleration and deceleration phase compared with PFP. Conclusions The peak flow of the 3F Enable SHV seems to be little higher compared with native aortic valves, thus simulating nearly physiologic conditions. Vorticity and strain rate are high during PFP and low during other phases and might have an influence on the aortic wall as well.