GENDER VARIATIONS IN THE MECHANICAL PROPERTIES OF ASCENDING AORTIC ANEURYSMS

摘要

The present study aimed to examine gender variations in the mechanical properties of ascending aortic aneurysms. Fresh tissue from ten patients undergoing graft replacement of the ascending aorta was classified according to gender and direction. The specimens were submitted to mechanical testing beyond rupture with evaluation of failure stress (tensile strength), failure strain (extensibility), and peak elastic modulus (maximum tissue stiffness). Failure strain was independent of gender in both circumferential and longitudinal specimens. Failure stress and peak elastic modulus were higher in male than female patients in circumferential, but not in longitudinal specimens. Tissue thickness did not vary with gender. In both genders, failure stress and peak elastic modulus were significantly higher in the circumferential compared to the longitudinal direction. The present findings relating to gender variations in the rupture properties of aneurysmal tissue may be responsible for the increased rupture risk documented by epidemiologic studies in women, as rupture develops when hemodynamic loads exceed the aortic wall strength.