Determination of the elastic modulus of ascending thoracic aortic aneurysm at different ranges of pressure using uniaxial tensile testing

Abstract

This study provides new data on the elastic modulus in the physiologic and hypertensive range that can be used in computational analysis and the design of bench-top models. The accuracy of computational analysis and bench-top models strongly depends on the knowledge of the elastic properties of the aortic wall. The mechanical properties presented in this study, with specific values for 2 locations (greater and lesser curvature) and 2 directions (circumferential, longitudinal), will increase our understanding of the mechanisms that precede rupture of an ascending aortic aneurysm.

Human dilated ascending aorta: Mechanical characterization via uniaxial tensile tests

“…During preconditioning and extension, load and displacement were continuously recorded with a sampling frequency of 10 Hz. It is worth noting that the adopted cross-head speed is the one proposed in [36,37].…”

“…In particular, some studies move from the presentation of new tools in imaging analysis to evidence possible alterations in the morphology and in the micro-structure of the diseased aortic tissues [26,27]. Other studies focus on the use of mechanical tests (uniaxial and biaxial tensile tests) to evaluate and compare mechanical properties of both healthy and diseased tissues [28][29][30][31][32][33] and, at the same time, to investigate factors which can influence tissue properties like location and orientation [23,[34][35][36][37], patient age [30,38,39], patient sex [39,40], and presence of concomitant pathologies [25,33,36,[41][42][43][44].…”

Patient-specific finite element analysis of ascending aorta aneurysms

“…Thus, in this study, the systolic AsAA meshes were transformed to obtain the unpressurized geometry using the following approach. Treating the AsAA as a thin-walled cylindrical pressure vessel as often done (8,12,18,20,23), the systolic wall tension in the circumferential (systolic hoop tension), t c sys , and axial directions, ta sys , are given by the Law of Laplace:…”

Effect of personalized external aortic root support on aortic root motion and distension in Marfan syndrome patients

“…Tensile strength of the aortic wall is not homogenous and shows directional changes; most studies have consistently shown that the aortic wall is less strong in the longitudinal direction [20,21] with preferential rupture perpendicular to its long axis when stress is applied in both directions [22]. Moreover, Khanafer et al studied tissue samples of human ascending aorta aneurysm and found that aneurysm diameter was more strongly correlated with increased longitudinal than circumferential wall stress [23]. All these findings suggest that longitudinal wall stress may be as important as circumferential stress in the pathogenesis of aortic dissection and may be the leading cause of a transverse tear along the long axis of the aorta.…”