Micromechanics of the fibrosa and the ventricularis in aortic valve leaflets

Veselý, Ivan; Noseworthy, R.

doi:10.1016/0021-9290(92)90249-z

Cited by 175 publications

(147 citation statements)

References 33 publications

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“…The arrangement of these fibers corresponds to the direction of highest tensile stress. In contrast, the ventricularis endures smaller tensile forces involved with initial opening and closing of the valve [30]. In addition to circumferentially oriented collagen, the largest and strongest collagen fiber bundles are localized in the areas of greatest tensile stress along the lower part of the commissure and coapting regions [22].…”

Section: Collagen Comprises a Significant Portion Of The Aortic Valvementioning

confidence: 99%

“…When stress is applied to the leaflet, initial extension is accomplished by straightening of the collagen crimp. Further stress causes the corrugations to unfold in the radial direction [30]. Together, collagen crimp and corrugations allow the fibrosa to extend further in the radial direction when compared to the circumferential direction.…”

Section: Collagen Comprises a Significant Portion Of The Aortic Valvementioning

confidence: 99%

“…These fiber sheets are the most significant contributor to the mechanical properties of the ventricularis [6,30], which can be demonstrated when all ECM components but elastin are removed when using NaOH digestion. After this treatment, the digested ventricularis matches the mechanical behavior of the undigested ventricularis radially, indicating a strong presence of elastin in the radial direction [30]. The elastic fibers within the ventricularis undergo considerable, continual stretch from the initial stage of closure, when blood flow vortices are starting to push the leaflets towards the valve orifice, to the final coapted position of the leaflets.…”

Section: Elastic Fibers Comprise a Significant Portion Of The Ventricmentioning

confidence: 99%

“…The elastic fiber structure in the spongiosa has been characterized much less than in the ventricularis, partly due to the difficulty in isolating its structure from the rest of the leaflet [30]. This elastic structure, however, has been observed during microdissection separating the leaflet [30,48], with scanning electron microscopy (SEM) [6,46], micro-computed tomography (micro-CT) [6], immunohistochemistry (IHC) [25], and autofluorescence imaging [49,50], which all have shown a fine elastic fiber network emanating from the ventricularis and connecting to the fibrosa.…”

Section: Elastic Fibers Comprise a Significant Portion Of The Ventricmentioning

confidence: 99%

See 3 more Smart Citations

Extracellular Matrix Organization, Structure, and Function

Wiltz¹,

Arevalos²,

Balaoing³

et al. 2013

Calcific Aortic Valve Disease

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Section: Collagen Comprises a Significant Portion Of The Aortic Valvementioning

confidence: 99%

Section: Collagen Comprises a Significant Portion Of The Aortic Valvementioning

confidence: 99%

Section: Elastic Fibers Comprise a Significant Portion Of The Ventricmentioning

confidence: 99%

Section: Elastic Fibers Comprise a Significant Portion Of The Ventricmentioning

confidence: 99%

See 2 more Smart Citations

Extracellular Matrix Organization, Structure, and Function

Wiltz¹,

Arevalos²,

Balaoing³

et al. 2013

Calcific Aortic Valve Disease

View full text Add to dashboard Cite

“…Like for many other soft tissues, initial measurements of valve leaflet tissue were measured by Instron-type uniaxial tester (Clark 1973;Missirlis and Chong 1978;Thubrikar et al 1980;Rousseau et al 1983;Sauren et al 1983;Vesely and Noseworthy 1992;Vesely and Lozon 1993). Valve tissue, even compared to other biological tissues, is particularly nonlinear, nonhomogeneous, and anisotropic.…”

Section: Tissue-scalementioning

confidence: 99%

On the multiscale modeling of heart valve biomechanics in health and disease

Weinberg

Shahmirzadi

Mofrad

2010

Biomech Model Mechanobiol

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Theoretical models of the human heart valves are useful tools for understanding and characterizing the dynamics of healthy and diseased valves. Enabled by advances in numerical modeling and in a range of disciplines within experimental biomechanics, recent models of the heart valves have become increasingly comprehensive and accurate. In this paper, we first review the fundamentals of native heart valve physiology, composition and mechanics in health and disease. We will then furnish an overview of the development of theoretical and experimental methods in modeling heart valve biomechanics over the past three decades. Next, we will emphasize the necessity of using multiscale modeling approaches in order to provide a comprehensive description of heart valve biomechanics able to capture general heart valve behavior. Finally, we will offer an outlook for the future of valve multiscale modeling, the potential directions for further developments and the challenges involved.

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The aortic valve microstructure: Effects of transvalvular pressure

Sacks

Smith

Hiester

1998

J. Biomed. Mater. Res.

131

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We undertook this study to establish a more quantitative understanding of the microstructural response of the aortic valve cusp to pressure loading. Fresh porcine aortic valves were fixed at transvalvular pressures ranging from 0 mmHg to 90 mmHg, and small-angle light scattering (SALS) was used to quantify the gross fiber structure of the valve cusps. At all pressures the fiber-preferred directions coursed along the circumferential direction. Increasing transvalvular pressure induced the greatest changes in fiber alignment between 0 and 1 mmHg, with no detectable change past 4 mmHg. When the fibrosa and ventricularis layers of the cusps were re-scanned separately, the fibrosa layer revealed a higher degree of orientation while the ventricularis was more randomly oriented. The degree of fiber orientation for both layers became more similar once the transvalvular pressure exceeded 4 mmHg, and the layers were almost indistinguishable by 60 mmHg. It is possible that, in addition to retracting the aortic cusp during systole, the ventricularis mechanically may contribute to the diastolic cuspal stiffness at high transvalvular pressures, which may help to prevent over distention of the cusp. Our results suggest a complex, highly heterogeneous structural response to transvalvular pressure on a fiber level that will have to be duplicated in future bioprosthetic heart valve designs.

show abstract

Micromechanics of the fibrosa and the ventricularis in aortic valve leaflets

Cited by 175 publications

References 33 publications

Extracellular Matrix Organization, Structure, and Function

Extracellular Matrix Organization, Structure, and Function

On the multiscale modeling of heart valve biomechanics in health and disease

The aortic valve microstructure: Effects of transvalvular pressure

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