Artery buckling analysis using a two-layered wall model with collagen dispersion

Abstract

Artery buckling has been proposed as a possible cause for artery tortuosity associated with various vascular diseases. Since microstructure of arterial wall changes with aging and diseases, it is essential to establish the relationship between microscopic wall structure and artery buckling behavior. The objective of this study was to developed arterial buckling equations to incorporate the two-layered wall structure with dispersed collagen fiber distribution. Seven porcine carotid arteries were tested for buckling to determine their critical buckling pressures at different axial stretch ratios. The mechanical properties of these intact arteries and their intima-media layer were determined via pressurized inflation test. Collagen alignment was measured from histological sections and modeled by a modified von-Mises distribution. Buckling equations were developed accordingly using microstructure-motivated strain energy function. Our results demonstrated that collagen fibers disperse around two mean orientations symmetrically to the circumferential direction (39.02°±3.04) in the adventitia layer; while aligning closely in the circumferential direction (2.06°±3.88) in the media layer. The microstructure based two-layered model with collagen fiber dispersion described the buckling behavior of arteries well with the model predicted critical pressures match well with the experimental measurement. Parametric studies showed that with increasing fiber dispersion parameter, the predicted critical buckling pressure increases. These results validate the microstructure-based model equations for artery buckling and set a base for further studies to predict the stability of arteries due to microstructural changes associated with vascular diseases and aging.

Twist buckling of veins under torsional loading

“…We found the fiber dispersion parameter κ to be in the range of 0.10-0.19 which is in close agreement with previous study on murine vein tissue (McGilvray et al 2010) and similar to porcine carotid arteries (Mottahedi and Han 2016). Interestingly, the fiber orientation of all veins was close to 70° indicating that fibers are more aligned towards the circumferential direction which was also observed in previous studies (McGilvray et al 2010; Herrera et al 2012; Badel et al 2013; Qi et al 2015).…”

“…The use of two-fiber strain energy density function allowed us to further explore the link of vein critical buckling load with its microstructure and extracellular matrix contents in pathological conditions (Liu et al 2014; Mottahedi and Han 2016). We found the fiber dispersion parameter κ to be in the range of 0.10-0.19 which is in close agreement with previous study on murine vein tissue (McGilvray et al 2010) and similar to porcine carotid arteries (Mottahedi and Han 2016).…”

“…C 10 , k 1 , k 2, κ are material constants. The parameter κ is the dispersion parameter that reflects the dispersion of collagen fiber alignment distribution (Gasser et al 2006; Mottahedi and Han 2016). …”

A Biomimetic Heparinized Composite Silk-Based Vascular Scaffold with sustained Antithrombogenicity

“…In order to achieve a functional blood vessel with three main cell layers (i.e. intima, media, and adventitia) 13 , the small-diameter vascular scaffold should have certain properties, including good biocompatibility, suitable mechanical properties (i.e. suitable flexibility, compliance matching that of native arteries suture retention strength and resistance to aneurysm formation), appropriate porosity for each vascular cells, degradation rate relative to extracellular matrix (ECM) deposition and very low thrombogenicity 14 , 15 .…”

What is The Correct Mechanical Model of Aorta Artery

“…Also the phenomena, model analyses, experimental measurements, effect on blood flow, and clinical relevance have been discussed. From this and further works Han et al clearly showed that mechanical buckling of aorta artery is an important issue for vasculature, in addition to wall stiffness and strength, and requires further studies [11][12][13][14][15][16][17][18][19][20].…”