Mechanical Properties of Intact Arterial Segments

Abstract

Due to their Windkessel function, the mechanical properties of arteries play an essential role in hemodynamics. Detailed knowledge of vascular rheology is diagnostically relevant for early detection of disease processes and is clinically important in vascular surgery and prosthetics. It is generally recognized that from a mechanical viewpoint arterial tissue is highly deformable, inelastic, incompressible, nonlinear and orthotropic (1, 9). However, considerable disagreement is evident in literature, concerning both the overall mechanical behavior of tubular arterial segments (3, 9, 12, 14) as well as the character of anisotropy displayed by vascular tissue (1, 3, 9, 12). Conflicting claims exist over the direction of anisotropy (3) and the question still appears open whether vascular tissue can be considered isotropic under certain circumstances (l, 4, 6, 13). The purpose of the present study was to examine the passive mechanical behavior of a wide variety of arteries and to find out which deformational aspects are common to arteries from different topographical sites. To develop a picture of wall mechanics as complete as possible, experiments covering a wide range of deformations both in the circumferential and longitudinal direction were considered. The anisotropic elastic response of the arterial tissue was analyzed using the concept of incremental moduli of elasticity.