A two-scale numerical study on the mechanobiology of abdominal aortic aneurysms

Abstract

Abdominal aortic aneurysms (AAAs) are a serious condition whose pathophysiology is related to phenomena occurring at different length scales. To gain a better understanding of the disease, this work presents a multi-scale computational study that correlates AAA progression with microstructural and mechanical alterations in the tissue. Macro-scale geometries of a healthy aorta and idealized aneurysms with increasing diameter are developed on the basis of existing experimental data and subjected to physiological boundary conditions. Subsequently, microscopic representative volume elements of the abluminal side of each macro-model are employed to analyse the local kinematics at the cellular scale. The results suggest that the formation of the aneurysm disrupts the micromechanics of healthy tissue, which could trigger collagen growth and remodelling by mechanosensing cells. The resulting changes to the macro-mechanics and microstructure of the tissue seem to establish a new homeostatic state at the cellular scale, at least for the diameter range investigated.

In vivo mechanical characterization of arterial wall using an inverse analysis procedure: application on an animal model of intracranial aneurysm

“…Furthermore, refining the numerical model and the theoretical assumptions may be a means of improving the procedure. A single-layer artery with an isotropic material was considered for this model, but multiple-layer anisotropic hyperelastic materials have also been proposed [ 42 , 57 , 58 ]. Local heterogeneities of the thickness and mechanical properties of the aneurysm walls could also be added to get close to clinical observations [ 47 ].…”