Experimental studies on different arteries include biaxial passive experiments on square specimens (green tissue samples PBW/L), active experiments on square and rectangular specimens (red tissue samples AB and AUL/C), and active and passive studies on intact cylindrical artery segments. Additional samples are provided for immunohistological analysis of the microstructure (yellow tissue samples H).

Atherosclerosis of coronary and carotid arteries is the leading cause of mortality and disability in industrialized nations. Both arteries are of great biomedical and clinical interest because they are prone to atherosclerosis and are often treated with balloon angioplasty, stenting or carotid endarterectomy to prevent myocardial infarction and stroke. Detailed knowledge of their mechanical behavior can greatly improve the preoperative planning of these therapies. For example, patient-specific finite element analysis can be used to simulate the balloon angioplasty and stenting procedure and optimize the choice of balloon and stent geometry. In addition, stresses and strains on cells and tissues have been shown to influence the development of atherosclerotic lesions. Three-dimensional mechanical models of the artery are therefore required to analyze the distribution of stresses and strains in the vessel wall. However, most biomechanical studies and constitutive models consider only the passive and not the active behavior of arteries in their computer simulations.

Our approach involves a holistic experimental study of the passive and active behavior of coronary and carotid arteries obtained from pigs. In a future phase, the approach is intended to be extended to human arteries. This will be achieved through passive and active uniaxial and biaxial extension tests on intact and sectioned specimens, as well as extension-inflation tests on intact arterial segments. The underlying microstructure responsible for the mechanical properties of the tested arterial tissues will be characterized by histological studies of collagen, elastin, and smooth muscle cells. Based on these data, a three-dimensional model capable of describing and predicting the active muscle contraction behavior in addition to the passive behavior of these important arteries will be developed, calibrated, and validated against the extensive data set.

The project is carried out at the Institute of Biomechanics in cooperation with Prof. Markus Böl (Institute of Mechanics and Adaptronics at the Technical University of Braunschweig). During the course of the project, regular research stays at the Technical University of Braunschweig in Germany are planned.

Funding: WEAVE project funded by the Austrian Science Fund (FWF) and the German Research Foundation (DFG); Lead: Graz University of Technology