Application of finite element analysis to the design of tissue leaflets for a percutaneous aortic valve

Smuts, Adriaan Nicolaas; Blaine, D.C.; Scheffer, Cornie; Weich, Hellmuth; Doubell, Anton; Dellimore, Kiran

doi:10.1016/j.jmbbm.2010.09.009

Cited by 56 publications

(48 citation statements)

References 33 publications

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“…Previously published literature on leaflet geometry was taken into account for design development [5][6][7]. Modelling of the leaflet structures was conducted in an unpressurized and closed configuration as a stress-free state.…”

Section: Design Of Leaflet-structuresmentioning

confidence: 99%

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Assessment of heart valve performance by finite-element design studies of polymeric leaflet-structures

Pfensig

Kaule

Saemann

et al. 2017

Current Directions in Biomedical Engineering

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For the treatment of severe symptomatic aortic valve stenosis, minimally invasive heart valve prostheses are increasingly used, especially for elderly patients. The current generation of devices is based on xenogenic leaflet material, involving limitations with regard to calcification and durability. Artificial polymeric leaflet-structures represent a promising approach for improvement of valve performance. Within the current work, finite-element analysis (FEA) design studies of polymeric leaflet structures were conducted. Design of an unpressurized and axiallysymmetric trileaflet heart valve was developed based on nine parameters. Physiological pressurization in FEA was specified, based on in vitro hydrodynamic testing of a commercially available heart valve prosthesis. Hyperelastic constitutive law for polymeric leaflet material was implemented based on experimental stress strain curves resulting from uniaxial tensile and planar shear testing. As a result of FEA, time dependent leaflet deformation of the leaflet structure was calculated. Obtained leaflet dynamics were comparable to in vitro performance of the analyzed prosthesis. As a major design parameter, the lunula angle has demonstrated crucial influence on the performance of the polymeric leaflet structures. FEA represented a useful tool for design of improved polymeric leaflet structures for minimally invasive implantable heart valve prostheses.

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Section: Design Of Leaflet-structuresmentioning

confidence: 99%

“…The influence of various design parameters on the leaflet performance has been investigated in structural mechanical FEA, previously [3][4][5]. Within the current work, we used FEA parametric studies for the design of a novel polymeric leaflet-structure for transcatheter heart valves.…”

Section: Introductionmentioning

confidence: 99%

Assessment of heart valve performance by finite-element design studies of polymeric leaflet-structures

Pfensig

Kaule

Saemann

et al. 2017

Current Directions in Biomedical Engineering

View full text Add to dashboard Cite

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“…In the literature, mathematical models related to TAVR are increasing. They can be related to the understanding of the mechanical behavior of the stented valve, the aortic root and the leaflet dynamics from a structural point of view 3,6,14,17,23,32,39 or to the hemodynamics inside the treated aortic root. 3,13,31,37 To the best of our knowledge, scientific publications which take into account both the mechanical and the fluid aspects in a coupled manner are absent.…”

Section: Introductionmentioning

confidence: 99%

Fluid–Structure Interaction Model of a Percutaneous Aortic Valve: Comparison with an In Vitro Test and Feasibility Study in a Patient-Specific Case

Pott

Mazza

et al. 2015

Ann Biomed Eng

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Transcatheter aortic valve replacement (TAVR) represents an established recent technology in a high risk patient base. To better understand TAVR performance, a fluid-structure interaction (FSI) model of a self-expandable transcatheter aortic valve was proposed. After an in vitro durability experiment was done to test the valve, the FSI model was built to reproduce the experimental test. Lastly, the FSI model was used to simulate the virtual implant and performance in a patient-specific case. Results showed that the leaflet opening area during the cycle was similar to that of the in vitro test and the difference of the maximum leaflet opening between the two methodologies was of 0.42%. Furthermore, the FSI simulation quantified the pressure and velocity fields. The computed strain amplitudes in the stent frame showed that this distribution in the patient-specific case is highly affected by the aortic root anatomy, suggesting that the in vitro tests that follow standards might not be representative of the real behavior of the percutaneous valve. The patient-specific case also compared in vivo literature data on fast opening and closing characteristics of the aortic valve during systolic ejection. FSI simulations represent useful tools in determining design errors or optimization potentials before the fabrication of aortic valve prototypes and the performance of tests.

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“…Transcatheter aortic valve replacement (TAVRs) is a percutaneous alternative to surgical aortic valve replacement (SAVR), which is used to treat intermediate and high-risk operable patient cohorts [1][2][3]. TAVRs consist of pericardial tissue leaflets sutured to a collapsible metallic stent.…”

Section: Introductionmentioning

confidence: 99%

Total ellipse of the heart valve: the impact of eccentric stent distortion on the regional dynamic deformation of pericardial tissue leaflets of a transcatheter aortic valve replacement

Gunning

Saikrishnan

Yoganathan

et al. 2015

J. R. Soc. Interface.

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Transcatheter aortic valve replacements (TAVRs) are a percutaneous alternative to surgical aortic valve replacements and are used to treat patients with aortic valve stenosis. This minimally invasive procedure relies on expansion of the TAVR stent to radially displace calcified aortic valve leaflets against the aortic root wall. However, these calcium deposits can impede the expansion of the device causing distortion of the valve stent and pericardial tissue leaflets. The objective of this study was to elucidate the impact of eccentric TAVR stent distortion on the dynamic deformation of the tissue leaflets of the prosthesis in vitro . Dual-camera stereophotogrammetry was used to measure the regional variation in strain in a leaflet of a TAVR deployed in nominal circular and eccentric (eccentricity index = 28%) orifices, representative of deployed TAVRs in vivo . It was observed that (i) eccentric stent distortion caused incorrect coaptation of the leaflets at peak diastole resulting in a ‘peel-back’ leaflet geometry that was not present in the circular valve and (ii) adverse bending of the leaflet, arising in the eccentric valve at peak diastole, caused significantly higher commissure strains compared with the circular valve in both normotensive and hypertensive pressure conditions (normotension: eccentric = 13.76 ± 2.04% versus circular = 11.77 ± 1.61%, p = 0.0014, hypertension: eccentric = 15.07 ± 1.13% versus circular = 13.56 ± 0.87%, p = 0.0042). This study reveals that eccentric distortion of a TAVR stent can have a considerable impact on dynamic leaflet deformation, inducing deleterious bending of the leaflet and increasing commissures strains, which might expedite leaflet structural failure compared to leaflets in a circular deployed valve.

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Application of finite element analysis to the design of tissue leaflets for a percutaneous aortic valve

Cited by 56 publications

References 33 publications

Assessment of heart valve performance by finite-element design studies of polymeric leaflet-structures

Assessment of heart valve performance by finite-element design studies of polymeric leaflet-structures

Fluid–Structure Interaction Model of a Percutaneous Aortic Valve: Comparison with an In Vitro Test and Feasibility Study in a Patient-Specific Case

Total ellipse of the heart valve: the impact of eccentric stent distortion on the regional dynamic deformation of pericardial tissue leaflets of a transcatheter aortic valve replacement

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