A uni-extension study on the ultimate material strength and extreme extensibility of atherosclerotic tissue in human carotid plaques

JOURNAL OF BIOMECHANICS

卷:48

Article

Teng, Zhongzhao^1,2  Feng, Jiaxuan³  Zhang, Yongxue³  Sutcliffe, Michael P. F.²  Huang, Yuan¹  Brown, Adam J.⁴  Jing, Zaiping³  Lu, Qingsheng³  Gillard, Jonathan H.¹ 

[1] Univ Cambridge, Dept Radiol, Cambridge CB2 0QQ, England

[2] Univ Cambridge, Dept Engn, Cambridge CB2 0QQ, England

[3] Changhai Hosp, Dept Vasc Surg, Shanghai, Peoples R China

[4] Univ Cambridge, Div Cardiovasc Med, Cambridge CB2 0QQ, England

关键词: Atherosclerosis;    Ultimate strength;    Extensibility;    Fibrous cap;    Lipid core;    Hemorrhage;   

DOI  :  10.1016/j.jbiomech.2015.09.037

来源: Elsevier

【 摘 要 】

Atherosclerotic plaque rupture occurs when mechanical loading exceeds its material strength. Mechanical analysis has been shown to be complementary to the morphology and composition for assessing vulnerability. However, strength and stretch thresholds for mechanics-based assessment are currently lacking. This study aims to quantify the ultimate material strength and extreme extensibility of atherosclerotic components from human carotid plaques. Tissue strips of fibrous cap, media, lipid core and intraplaque hemorrhage/thrombus were obtained from 21 carotid endarterectomy samples of symptomatic patients. Uni-extension test with tissue strips was performed until they broke or slid. The Cauchy stress and stretch ratio at the peak loading of strips broken about 2 mm away from the clamp were used to characterize their ultimate strength and extensibility. Results obtained indicated that ultimate strength of fibrous cap and media were 158.3 [72.1, 259.3] kPa (Median [Inter quartile range]) and 247.6 [169.0, 419.9] kPa, respectively; those of lipid and intraplaque hemorrhage/thrombus were 68.8 [48.5, 86.6] kPa and 83.0 [52.1, 124.9] kPa, respectively. The extensibility of each tissue type were: fibrous cap -1.18 [1.10, 1.27]; media -1.21 [1.17,1.32]; lipid - 1.25 [1.11, 130] and intraplaque hemorrhage/thrombus - 1.20 [1.17, 1.44]. Overall, the strength of fibrous cap and media were comparable and so were lipid and intraplaque hemorrhage/thrombus. Both fibrous cap and media were significantly stronger than either lipid or intraplaque hemorrhage/thrombus. All atherosclerotic components had similar extensibility. Moreover, fibrous cap strength in the proximal region (closer to the heart) was lower than that of the distal. These results are helpful in understanding the material behavior of atherosclerotic plaques. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

【 授权许可】

Free