Mechanical Properties of Ascending Thoracic Aortic Aneurysm (ATAA): Association with Valve Morphology

Abstract

Type A aortic dissection (AoD) of an ascending thoracic aortic aneurysm (ATAA) is a life-threatening cardiovascular emergency with a high potential for death. AoD represents a devastating separation of elastic aortic layers occurring when the hemodynamic loads on the diseased wall exceed the adhesive strength between layers. The goal of this study was to evaluate and compare the dissection properties of non-aneurysmal and aneurysmal human ascending thoracic aortas from patients with bicuspid aortic valve (BAV) and normal tricuspid aortic valve (TAV) morphologies using biomechanical delamination testing. Following complete delamination of ATAA tissue samples, tensile tests were performed on each delaminated half for comparison of their tensile strengths. Results evinced that the aneurysmal aortas with BAV and TAV have lower delamination properties than non-aneurysmal aorta, and that ATAA with BAV has lower S d than TAV, suggesting an apparent propensity of AoD.