Evolving anisotropy and degree of elastolytic insult in abdominal aortic aneurysms: Potential clinical relevance?

JOURNAL OF BIOMECHANICS

卷:47

Article

Wilson, John S.¹  Humphrey, J. D.^1,2 

[1] Yale Univ, Dept Biomed Engn, New Haven, CT 06520 USA

[2] Yale Univ, Sch Med, Vasc Biol & Therapeut Program, New Haven, CT 06520 USA

关键词: Growth and remodeling;    Computational biomechanics;    Stiffness;    Rupture risk;    Axial stress;    Elastin damage;   

DOI  :  10.1016/j.jbiomech.2014.07.003

来源: Elsevier

【 摘 要 】

Accurately estimating patient-specific rupture risk remains a primary challenge in timing interventions for abdominal aortic aneurysms (AAAs). By re-analyzing published biaxial mechanical testing data from surgically repaired human AAAs, material anisotropy emerged as a potentially important determinant of patient-specific lesion progression. That is, based on a new classification scheme, we discovered that anisotropic aneurysmal specimens correlated with increased patient age at surgery when compared with more isotropic specimens (79.7 vs. 70.9 years, p <0.002), despite no significant difference in maximum diameter. Furthermore, using an idealized axisymmetric, finite-element growth and remodeling model of AAA progression, we found that both the initial axial extent of elastin loss and ongoing damage to elastin in the shoulder region of the AAA directly affected the degree of anisotropy as the lesion evolved, with more extensive insults increasing the anisotropy. This effect appeared to be mediated by alterations in axial loading and subsequent differences in orientation of deposited collagen fibers. While the observed increased age before surgical intervention may suggest a potential benefit of anisotropic remodeling, future biaxial tests coupled with pre-surgical data on expansion rates and detailed theoretical analyses of the biostability of a lesion as a function of anisotropy will be required to erify its clinical relevance to patient-specific rupture risk. (C) 2014 Elsevier Ltd. All rights reserved.

【 授权许可】

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