Estimating Arterial Cyclic Strain from the Spacing of Endothelial Nuclei
- PDF / 4,555,125 Bytes
- 20 Pages / 595.276 x 790.866 pts Page_size
- 86 Downloads / 176 Views
SP ISS: EXPERIMENTAL ADVANCES IN CARDIOVASCULAR BIOMECHANICS
Estimating Arterial Cyclic Strain from the Spacing of Endothelial Nuclei E.M. Rowland 1 & E.L. Bailey 1,2 & P.D. Weinberg 1 Received: 8 January 2020 / Accepted: 5 August 2020 # The Author(s) 2020
Abstract Background The non-uniform distribution of atherosclerosis within the arterial system is widely attributed to variation in haemodynamic wall shear stress. It may also depend on variation in pressure-induced stresses and strains within the arterial wall; these have been less widely investigated, at least in part because of a lack of suitable techniques. Objectives Here we show that local arterial strain can be determined from impressions left by endothelial cells on the surface of vascular corrosion casts made at different pressures, even though only one pressure can be examined in each vessel. The pattern of pits in the cast caused by protruding endothelial nuclei was subject to “retro-deformation” to identify the pattern that would have occurred in the absence of applied stresses. Methods Retaining the nearest-neighbour pairs found under this condition, changes in nearest-neighbour vectors were calculated for the pattern seen in the cast, and the ratio of mean changes at different pressures determined. This approach removes errors in simple nearest-neighbour analyses caused by the nearest neighbour changing as deformation occurs. Results The accuracy, precision and robustness of the approach were validated using simulations. The method was implemented using confocal microscopy of casts of the rabbit aorta made at systolic and diastolic pressures; results agreed well with the ratio of the macroscopic dimensions of the casts. Conclusions Applying the new technique to areas around arterial branches could support or refute the hypothesis that the development of atherosclerosis is influenced by mural strain, and the method may be applicable to other tissues. Keywords Arterial strain . Cyclic arterial strain . Corrosion casting . Nuclear spacing . Nearest neighbour analysis . Aorta
Introduction Atherosclerosis is characterised by the accumulation of lipids, cells and fibrous proteins within the arterial wall. Systemic factors govern its prevalence and severity but they cannot account for the highly non-uniform distribution of lesions within the arterial system. Its predilection for areas of branching and curvature has given rise to the view that Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11340-020-00655-9) contains supplementary material, which is available to authorized users. * P.D. Weinberg [email protected] 1
Department of Biomedical Engineering, Imperial College London, London SW7 2AZ, UK
2
Present address: School of Life Sciences, University of Glasgow, Glasgow G12 8QQ,, UK
haemodynamic stresses play an important role in the pathogenesis of the disease. Low and oscillatory wall shear stress (WSS), the frictional force per unit area between the blood and the vessel wall, have been the sub
Data Loading...
