Passive and Active Triaxial Wall Mechanics in a Two-Layer Model of Porcine Coronary Artery

Abstract

Triaxial active and passive mechanical properties of coronary arteries are needed for understanding arterial mechanics in health and disease. The aim of the study was to quantify both active and passive strain energy functions in circumferential, axial and radial directions based on the experimental measurement. Moreover, a two-layer computational model was used to determine the transmural distribution of stresses and strains across the vessel wall. The first Piola-Kirchhoff stresses in the three normal directions had the approximate relationship as:. The two-layer model showed that circumferential Cauchy stresses increased significantly from the intima layer to the interface between media and adventitia layers (from ~80 to 160 kPa), dropped abruptly at the interface (from ~160 to <5 kPa), and increased slightly towards the outer boundary of the adventitia layer. In contrast, absolute values of radial Cauchy stress decreased continuously from the inner to outer boundaries of the vessel wall (from ~11 kPa to zero). Smooth muscle cell contraction significantly increased the ratio of radial to circumferential Cauchy stresses at the intima-media layer, which had the highest values at the intima layer.

Design and Simulation of the Biomechanics of Multi-Layered Composite Poly(Vinyl Alcohol) Coronary Artery Grafts

“…The contributions of the two layers to the mechanical properties of the wall must therefore be considered separately. This is in contrast to studies performed using porcine coronary artery data, where the intima and media are generally analysed as a combined intima–media layer ( 16 , 17 ). These results reflect the limitations associated with using such bi-layered models (i.e., models comprised of intima–media and adventitia) as the basis to develop functional coronary artery grafts.…”

“…As the luminal layer, the intima supports the endothelium. It is generally thought that the media is responsible for arterial wall properties at physiological pressure (15)(16)(17). However, studies in aged human coronary arteries suggest that the intima bears more load in arteries with non-atherosclerotic intimal thickening (18).…”

Acute Tachycardia Increases Aortic Distensibility, but Reduces Total Arterial Compliance Up to a Moderate Heart Rate

“…Similar to previous studies (Huo et al, 2012 , 2013 ; Lu et al, 2017 ), arteries with diameters of 300–600 μm were dissected free of periarterial tissues. Two black marks were made at the two ends of the artery with waterproof India ink.…”

The influence of active contractions on stress distribution in the wall of aresistance blood vessel

“…Из (1) и (3) следует равенство [14]. Учет данных о свойствах и ориентации отдельных клеток и волокон в двух слоях стенки коронарной артерии привел к заключению, что радиальный градиент окружного напряжения в активном сосуде может быть как положительным, так и отрицательным [13].…”