Reynolds shear stress for textile prosthetic heart valves in relation to fabric design

Bark, David; Yousefi, Atieh; Forleo, Marcio; Vaesken, Antoine; Heim, Frédéric; Dasi, Lakshmi Prasad

doi:10.1016/j.jmbbm.2016.01.016

Cited by 4 publications

(3 citation statements)

References 33 publications

(36 reference statements)

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“…Based on this premise, multiple studies focused on developing polymeric heart valves[4, 15, 39] (PHVs) made out of homogeneous materials or more recently as inhomogeneous textile heart valves (THVs) [1]. In another study we demonstrated that a linear low density polyurethane (LLDPE) PHV enhanced with hyaluronic acid would provide good hemocompatibility for prosthetic heart valves [26].…”

Section: Introductionmentioning

confidence: 99%

Effect of Arched Leaflets and Stent Profile on the Hemodynamics of Tri-Leaflet Flexible Polymeric Heart Valves

2016

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Polymeric heart valves (PHV) can be engineered to serve as alternatives for existing prosthetic valves due to higher durability and hemodynamics similar to bioprosthetic valves. The purpose of this study is to evaluate the effect of geometry on PHVs coaptation and hemodynamic performance. The two geometric factors considered are stent profile and leaflet arch length, which were varied across six valve configurations. Three models were created with height to diameter ratio of 0.6, 0.7, and 0.88. The other three models were designed by altering arch height to stent diameter ratio, to be 0, 0.081, and 0.116. Particle image velocimetry (PIV) experiments were conducted on each PHV to characterize velocity, vorticity, turbulent characteristics, effective orifice area (EOA), and regurgitant fraction. This study revealed that the presence of arches as well as higher stent profile reduced regurgitant flow down to 5%, while peak systole downstream velocity reduced to 58% and Reynolds Shear Stress values reduced 40%. Further, earlier reattachment of the forward flow jet was observed in PHVs with leaflet arches. These findings indicate that although both geometric factors help diminish the commissural gap during diastole, leaflet arches induce a larger jet opening, yielding to earlier flow reattachment and lower energy dissipation.

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Section: Introductionmentioning

confidence: 99%

Effect of Arched Leaflets and Stent Profile on the Hemodynamics of Tri-Leaflet Flexible Polymeric Heart Valves

2016

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“…Despite the fact that the maximum RSS of the bileaflet valve is almost identical to that of the trileaflet valve, the bileaflet prosthesis presents a higher overall RSS level in the downstream conduit. This could be attributed to the high leaflet profile of the bileaflet design (Bark et al, 2016).…”

Section: Rss Distributionsmentioning

confidence: 99%

In vitro Assessment of the Impacts of Leaflet Design on the Hemodynamic Characteristics of ePTFE Pulmonary Prosthetic Valves

Zhu

Wei

Yuan

et al. 2020

Front. Bioeng. Biotechnol.

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Prosthetic pulmonary valves are widely used in the management procedures of various congenital heart diseases, including the surgical pulmonary valve replacement (PVR) and right ventricular outflow tract reconstruction (RVOT). The discouraging long-term outcomes of standard prostheses, including homografts and bioprosthetic, constrained their indications. Recent developments in the expanded-polytetrafluoroethylene (ePTFE) pulmonary prosthetic valves provide promising alternatives. In this study, the hemodynamic characteristics of bileaflet and trileaflet ePTFE valve designs were experimentally evaluated. The in vitro tests were performed under the right ventricle (RV) flow conditions by using an in vitro RV circulatory system and particle image velocimetry (PIV). The leaflet kinetics, trans-valvular pressure gradients, effective orifice areas, regurgitant fractions, energy losses, velocity fields, and Reynolds shear stress (RSS) in both prostheses were evaluated. The opening of the bileaflet and trileaflet valve takes 0.060 and 0.088 s, respectively. The closing of the former takes 0.140 s, in contrast to 0.176 s of the latter. The trans-valvular pressure is 6.8 mmHg in the bileaflet valve vs. 7.9 mmHg in the trileaflet valve. The effective orifice area is 1.83 cm 2 in the bileaflet valve and 1.72 cm 2 in the trileaflet valve. The regurgitant fraction and energy loss of bileaflet are 7.13% and 82 mJ, which are 7.84% and 101.64 mJ in its bileaflet counterpart. The maximum RSS of 48.0 and 49.2 Pa occur at the systole peak in the bileaflet and trileaflet valve, respectively. A higher average RSS level is found in the bileaflet valve. The results from this preliminary study indicate that the current bileaflet prosthetic valve design is capable of providing a better overall hemodynamic performance than the trileaflet design.

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“…This is then supported by the formation of vortex structures at the end of the three cusps, observed in the PIV experiment. Bark et al (2016), observed the flow fields generated by different textile fabrication techniques through time-resolved PIV technique. Mokhtar et al (2016), performed the PIV experiment to analyze the effect of stent placement on the flow pattern, velocity, and pressure with hope to reduce the size of the aneurysm issue.…”

Section: Introductionmentioning

confidence: 99%

Particle Image Velocimetry and Finite Volume Method Study of Bi-leaflet Artificial Heart Valve

Bakar

Abas

Mokhtar

et al. 2018

JAFM

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The key feature of the bi-leaflet valve is the geometry of the two leaflets, which can be crucial in determining the flow field. In this paper, observations were made on the flow pattern of the blood through the use of bi-leaflet type mechanical prosthetic valve (MHV). Finite volume method (FVM) analysis was conducted using fluidstructure interaction (FSI) method that solved on a dynamic mesh. In terms of the validation, particle image velocimetry (PIV) was used to verify the findings obtained from FVM analysis. The results of velocity and vorticity were the main parameters to be compared. Based on the findings, the results computed for the leaflets motion and the flow field using FVM was found to be in agreement with PIV experimental data. The pressure obtained for the simulation is in the range of 10,666-16,000 Pa, which is an ideal and healthy blood pressure level of human. The vorticity was observed to be formed behind the valve with DVI value of 1.275 (simulation) and 1.457 (experiment), lower than the expected range for a normal DVI in mitral valve. The maximum shear stress achieved (22.5481 Pa) is in the range of platelets activation, which could lead to thrombus formation. The maximum Von Mises stress was found to be at the hinge region of the bi-leaflet valve. These results will serve as a basis for valve design to improve the hemodynamic properties of the heart valve.

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Reynolds shear stress for textile prosthetic heart valves in relation to fabric design

Cited by 4 publications

References 33 publications

Effect of Arched Leaflets and Stent Profile on the Hemodynamics of Tri-Leaflet Flexible Polymeric Heart Valves

Effect of Arched Leaflets and Stent Profile on the Hemodynamics of Tri-Leaflet Flexible Polymeric Heart Valves

In vitro Assessment of the Impacts of Leaflet Design on the Hemodynamic Characteristics of ePTFE Pulmonary Prosthetic Valves

Particle Image Velocimetry and Finite Volume Method Study of Bi-leaflet Artificial Heart Valve

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