Stented valve dynamic behavior induced by polyester fiber leaflet material in transcatheter aortic valve devices

Leaflet thrombosis is a complication associated with transcatheter aortic valve (TAV) replacement (TAVR) correlated with sinus flow stasis. Sinus hemodynamics are important because they dictate shear stress and washout necessary to avoid stasis on TAV leaflets. Sinus flow is controlled by TAV axial deployment position but little is known regarding TAV axis misalignment effect. This study aims to elucidate TAV angular misalignment with respect to aortic root axis effect on sinus flow stasis potentially leading to leaflet thrombosis. Sinus hemodynamics were assessed in vitro using particle-image velocimetry in three different angular misalignments with respect to aorta axis: untilted, tilted away from the sinus and tilted towards sinus. A 26 mm Edwards SAPIEN3 was implanted in a 3D printed model of an anatomically realistic aortic root. TAV hemodynamics, sinus vortex tracking, leaflet shear stress probability density functions, and sinus blood time to washout were calculated. While pressure gradients differed insignificantly, blood velocity and vorticity decreased significantly in both tilted cases sinuses. Shear stress probability near the leaflet decreases with tilt indicating stasis. TAV tilted away from the sinus is the most unfavorable scenario with poor washout. TAV axial misalignment adds to factors list that could influence leaflet thrombosis risk through modifying sinus hemodynamics and washout.

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“…Viscous shear stress field was evaluated consistently with Hatoum et al 12, 13, 18, 19, 22, 23 and Moore et al 21 .…”

Section: Methodsmentioning

confidence: 99%

Sinus Hemodynamics Variation with Tilted Transcatheter Aortic Valve Deployments

et al. 2018

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“…Hemodynamic parameters were evaluated under pulsatile flow conditions created by a left heart simulator ( Figure 1f) yielding physiological flow and pressure curves as previously described [6][7][8][19][20][21]. The desired outputs can be summarized as establishing a systolic to diastolic pressure of 98/68 mmHg and 100/61 mmHg, an 81 bpm heart rate, a systolic duration of 33%, and a cardiac output of 4.2 L/min and 5.15 L/min for the bicuspid and tricuspid valves, respectively.…”

Section: Hemodynamic Assessmentmentioning

confidence: 99%

“…Velocity vectors were calculated using adaptive cross-correlation algorithms. Further details of PIV measurements can be found in Hatoum et al [6][7][8][19][20][21][22].…”

Section: Particle Image Velocimetry (Piv)mentioning

confidence: 99%

“…This may trigger pathways for various valvular heart diseases [6,11,19]. Specifically, turbulence is characterized by a tremendous rise in spatial and temporal velocity fluctuations [19,21]. These turbulent fluctuations in velocity cause non-physiological shear stresses that blood cells and platelets experience [41][42][43] and are dependent on the valve geometry (smoothness of inflow, calcification distribution, etc.…”

Section: Comparison Between Idealized and Anatomical Sinus Geometriesmentioning

confidence: 99%

“…), leaflet performance (opening, closing, calcium buildup), and distal diameter of the aorta relative to the valve orifice area. Reynolds shear stresses (turbulent stresses have been correlated in literature with hemolysis and platelet activation [19,21,[44][45][46]. Turbulent non-physiological flow (that happens due to valve deterioration) was connected with blood damage, such as platelet activation, thrombus formation and hemolysis [47][48][49][50][51].…”

Section: Comparison Between Idealized and Anatomical Sinus Geometriesmentioning

confidence: 99%

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Sinus Hemodynamics in Representative Stenotic Native Bicuspid and Tricuspid Aortic Valves: An In-Vitro Study

Hatoum

Dasi

2018

Fluids

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(1) The study’s objective is to assess sinus hemodynamics differences between stenotic native bicuspid aortic valve (BAV) and native tricuspid aortic valve (TrAV) sinuses in order to assess sinus flow shear and vorticity dynamics in these common pathological states of the aortic valve. (2) Representative patient-specific aortic roots with BAV and TrAV were selected, segmented, and 3D printed. The flow dynamics within the sinus were assessed in-vitro using particle image velocimetry in a left heart simulator at physiological pressure and flow conditions. Hemodynamic data calculations, vortex tracking, shear stress probability density functions and sinus washout calculations based on Lagrangian particle tracking were performed. (3) (a) At peak systole, velocity and vorticity in BAV reach 0.67 ± 0.02 m/s and 374 ± 5 s−1 versus 0.49 ± 0.03 m/s and 293 ± 3 s−1 in TrAV; (b) Aortic sinus vortex is slower to form but conserved in BAV sinus; (c) BAV shear stresses exceed those of TrAV (1.05 Pa versus 0.8 Pa); (d) Complete TrAV washout was achieved after 1.5 cycles while it was not for BAV. 4) In conclusion, sinus hemodynamics dependence on the different native aortic valve types and sinus morphologies was clearly highlighted in this study.

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Transcatheter Heart Valves: A Biomaterials Perspective

Bui

Khair

Yeats

et al. 2021

Adv Healthcare Materials

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Heart valve disease is prevalent throughout the world, and the number of heart valve replacements is expected to increase rapidly in the coming years. Transcatheter heart valve replacement (THVR) provides a safe and minimally invasive means for heart valve replacement in high‐risk patients. The latest clinical data demonstrates that THVR is a practical solution for low‐risk patients. Despite these promising results, there is no long‐term (>20 years) durability data on transcatheter heart valves (THVs), raising concerns about material degeneration and long‐term performance. This review presents a detailed account of the materials development for THVRs. It provides a brief overview of THVR, the native valve properties, the criteria for an ideal THV, and how these devices are tested. A comprehensive review of materials and their applications in THVR, including how these materials are fabricated, prepared, and assembled into THVs is presented, followed by a discussion of current and future THVR biomaterial trends. The field of THVR is proliferating, and this review serves as a guide for understanding the development of THVs from a materials science and engineering perspective.

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Stented valve dynamic behavior induced by polyester fiber leaflet material in transcatheter aortic valve devices

Abstract: PGs, LFs, PIs and E were improved with DS-RT compared to other textile TAVs and RS-DB. Despite achieving more RSS than the rest of TAVs, DS-RT still falls within the same range of RSS produced by the other 2 valves and control exceeding the threshold for platelet activation.

Cited by 22 publications

References 35 publications

Sinus Hemodynamics Variation with Tilted Transcatheter Aortic Valve Deployments

Sinus Hemodynamics Variation with Tilted Transcatheter Aortic Valve Deployments

Sinus Hemodynamics in Representative Stenotic Native Bicuspid and Tricuspid Aortic Valves: An In-Vitro Study

Transcatheter Heart Valves: A Biomaterials Perspective

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