Influence of differing material properties in media and adventitia on arterial adaptation — application to aneurysm formation and rupture

Schmid, H., Grytsan, A., Poshtan, E., Watton, P.N. and Itskov, M. (2013) Influence of differing material properties in media and adventitia on arterial adaptation — application to aneurysm formation and rupture. Computer Methods in Biomechanics and Biomedical Engineering, 16(1), pp. 33-53. (doi: 10.1080/10255842.2011.603309) (PMID:22149119)

Abstract

Experimental and computational studies suggest a substantial variation in the mechanical responses and collagen fibre orientations of the two structurally important layers of the arterial wall. Some observe the adventitia to be an order of magnitude stiffer than the media whilst others claim the opposite. Furthermore, studies show that molecular metabolisms may differ substantially in each layer. Following a literature review that juxtaposes the differing layer-specific results we create a range of different hypothetical arteries: (1) with different elastic responses, (2) different fibre orientations, and (3) different metabolic activities during adaptation. We use a finite element model to investigate the effects of those on: (1) the stress response in homeostasis; (2) the time course of arterial adaptation; and (3) an acute increase in luminal pressure due to a stressful event and its influence on the likelihood of aneurysm rupture. Interestingly, for all hypothetical cases considered, we observe that the adventitia acts to protect the wall against rupture by keeping stresses in the media and adventitia below experimentally observed ultimate strength values. Significantly, this conclusion holds true in pathological conditions.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Watton, Dr Paul
• Authors: Schmid, H., Grytsan, A., Poshtan, E., Watton, P.N., and Itskov, M.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Mathematics
• Journal Name: Computer Methods in Biomechanics and Biomedical Engineering
• Publisher: Taylor and Francis (Routledge)
• ISSN: 1025-5842
• ISSN (Online): 1476-8259
• Published Online: 08 December 2011