Mechanical Behavior of Vessel Wall: A Comparative Study of Aorta, Vena Cava, and Carotid Artery

Silver, Frederick H.; Snowhill, Patrick B.; Foran, David J.

doi:10.1114/1.1581287

Cited by 130 publications

(140 citation statements)

References 43 publications

Supporting

Mentioning

131

Contrasting

Order By: Relevance

“…This led to increased central AS. 50 A possible explanation for the observed differences in the PPP/CPP ratio between static handgrip and the dynamic exercise protocols could be that peripheral vasodilatation and a consequent fall in the peripheral AS occurs only during dynamic exercise. This results in lower amplitude of the reflected wave and finally lower augmentation in central pressure.…”

Section: Lydakis Et Almentioning

confidence: 98%

Changes of central haemodynamic parameters during mental stress and acute bouts of static and dynamic exercise

et al. 2008

View full text Add to dashboard Cite

Chronic dynamic (aerobic) exercise decreases central arterial stiffness, whereas chronic resistance exercise evokes the opposite effect. Nevertheless, there is little information available on the effects of acute bouts of exercise. Also, there is limited data showing an increase of central arterial stiffness during acute mental stress. This study aimed to determine the effect of acute mental and physical (static and dynamic exercise) stress on indices of central arterial stiffness. Fifteen young healthy volunteers were studied. The following paradigms were performed: (1) 2 min of mental arithmetic, (2) short bouts (20 s) of static handgrip at 20 and 70% of maximal voluntary contraction (MVC), (3) fatiguing handgrip at 40% MVC and (4) incremental dynamic knee extensor exercise. Central aortic waveforms were assessed using SphygmoCor software. As compared to baseline, pulse wave transit time decreased significantly for all four interventions indicating that central arterial stiffness increased. During fatiguing handgrip there was a fall in the ratio of peripheral to central pulse pressure from 1.69 ± 0.02 at baseline to 1.56±0.05 (Po0.05). In the knee extensor protocol a nonsignificant trend for the opposite effect was noted. The augmentation index increased significantly during the arithmetic, short static and fatiguing handgrip protocols, whereas there was no change in the knee extensor protocol. We conclude that (1) during all types of acute stress tested in this study (including dynamic exercise) estimated central stiffness increased, (2) during static exercise the workload posed on the left ventricle (expressed as change in central pulse pressure) is relatively higher than that posed during dynamic exercise (given the same pulse pressure change in the periphery).

show abstract

Section: Lydakis Et Almentioning

confidence: 98%

Changes of central haemodynamic parameters during mental stress and acute bouts of static and dynamic exercise

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Specifically, inflation [35,38], planar biaxial [20,24] and uniaxial [11,32] testing are preferable in-vitro mechanical test protocols for vascular tissue. Here, animal models remain popular in clinical hypothesis testing, where specifically the pig carotid artery has a central role.…”

Section: Introductionmentioning

confidence: 99%

Microstructural quantification of collagen fiber orientations and its integration in constitutive modeling of the porcine carotid artery

et al. 2016

View full text Add to dashboard Cite

Background Mechanical characteristics of vascular tissue may play a role in different arterial pathologies, which, amongst others, requires robust constitutive descriptions to capture the vessel wall’s anisotropic and non-linear properties.Specifically, the complex 3D network of collagen and its interaction with other structural elements has a dominating effect of arterial properties at higher stress levels.The aim of this study is to collect quantitative collagen organization as well as mechanical properties to facilitate structural constitutive models for the porcine carotid artery.This helps the understanding of the mechanics of swine carotid arteries, being a standard in clinical hypothesis testing, in endovascular preclinical trials for example. Method Porcine common carotid arteries (n = 10) were harvested and used to (i) characterize the collagen fiber organization with polarized light microscopy, and (ii) the biaxial mechanical properties by inflation testing.The collagen organization was quantified by the Bingham orientation density function (ODF), which in turn was integrated in a structural constitutive model of the vessel wall.A one-layered and thick-walled model was used to estimate mechanical constitutive parameters by least-square fitting the recorded in vitro inflation test results.Finally, uniaxial data published elsewhere were used to validate the mean collagen organization described by the Bingham ODF. Results Thick collagen fibers, i.e.the most mechanically relevant structure, in the common carotid artery are dispersed around the circumferential direction.In addition, almost all samples showed two distinct families of collagen fibers at different elevation, but not azimuthal, angles.Collagen fiber organization could be accurately represented by the Bingham ODF (¿1,2,3=[13.5,0.0,25.2] and ¿1,2,3=[14.7,0.0,26.6]; average error of about 5%), and their integration into a structural constitutive model captured the inflation characteristics of individual carotid artery samples.Specifically, only four mechanical parameters were required to reasonably (average error from 14% to 38%) cover the experimental data over a wide range of axial and circumferential stretches.However, it was critical to account for fibrilar links between thick collagen fibers.Finally, the mean Bingham ODF provide also good approximation to uniaxial experimental data. Conclusions The applied structural constitutive model, based on individually measured collagen orientation densities, was able to capture the biaxial properties of the common carotid artery. Since the model required coupling amongst thick collagen fibers, the collagen fiber orientations measured from polarized light microscopy, alone, seem to be insufficient structural information. Alternatively, a larger dispersion of collagen fiber orientations, that is likely to arise from analyzing larger wall sections, could have had a similar effect, i.e. could have avoided coupling amongst thick collagen fibers.Peer ReviewedPostprint (author's final draft

show abstract

“…elastin, collagen and vascular muscle cells (Silver et al 2003;Vito and Dixon 2003;Zhou and Fung 1997). Significant effort has been put into developing constituent-based or structural strain energy functions (SEFs) for the vascular tissue, that take into account the individual mechanical contribution of each intramural element Gasser et al 2006;Gundiah et al 2009;Holzapfel et al 2000;Zulliger et al 2004a,b) and therefore provide a solid base to study mechanical properties of the tissue in health and disease.…”

Section: Introductionmentioning

confidence: 99%

Role of elastin anisotropy in structural strain energy functions of arterial tissue

Rezakhaniha

Fonck

Genoud

et al. 2010

Biomech Model Mechanobiol

View full text Add to dashboard Cite

The vascular wall exhibits nonlinear anisotropic mechanical properties. The identification of a strain energy function (SEF) is the preferred method to describe its complex nonlinear elastic properties. Earlier constituent-based SEF models, where elastin is modeled as an isotropic material, failed in describing accurately the tissue response to inflation-extension loading. We hypothesized that these shortcomings are partly due to unaccounted anisotropic properties of elastin. We performed inflation-extension tests on common carotid of rabbits before and after enzymatic degradation of elastin and applied constituent-based SEFs, with both an isotropic and an anisotropic elastin part, on the experimental data. We used transmission electron microscopy (TEM) and serial block-face scanning electron microscopy (SBFSEM) to provide direct structural evidence of the assumed anisotropy. In intact arteries, the SEF including anisotropic elastin with one family of fibers in the circumferential direction fitted better the inflation-extension data than the isotropic SEF. This was supported by TEM and SBFSEM imaging, which showed interlamellar elastin fibers in the circumferential direction. In elastin-degraded arteries, both SEFs succeeded equally well in predicting anisotropic wall behavior. In elastase-treated arteries fitted with the anisotropic SEF for elastin, collagen engaged later than in intact arteries. We conclude that constituent-based models with an anisotropic elastin part characterize more accurately the mechanical properties of the arterial wall when compared to models with simply an isotropic elastin. Microstructural imaging based on electron microscopy techniques provided evidence for elastin anisotropy. Finally, the model suggests a later and less abrupt collagen engagement after elastase treatment.

show abstract

Mechanical Behavior of Vessel Wall: A Comparative Study of Aorta, Vena Cava, and Carotid Artery

Cited by 130 publications

References 43 publications

Changes of central haemodynamic parameters during mental stress and acute bouts of static and dynamic exercise

Changes of central haemodynamic parameters during mental stress and acute bouts of static and dynamic exercise

Microstructural quantification of collagen fiber orientations and its integration in constitutive modeling of the porcine carotid artery

Role of elastin anisotropy in structural strain energy functions of arterial tissue

Contact Info

Product

Resources

About