2.8 Unique Patterns of Elastin Degradation in Ascending Aortic Aneurysms in Bicuspid Aortic Valve Patients

Bicuspid aortic valve patients (BAV) are associated with increased risk of ascending aortic aneurysms. However, is unclear whether matrix degradation varies in different ascending aneurysm aetiologies. To determine whether the micromechanical and biochemical properties elastin microstructure in BAV-A exhibit unique properties as compared to idiopathic degenerative aneurysm (DA) for the same aortic size. Aortic tissue was obtained from patients undergoing aneurysmal repair surgery (BAV-A; n = 15 and DA; n = 15). Coronary artery by-pass graft punch biopsies served as controls (CABG; n = 9). The elastic modulus (E) was measured with nanoindentation for the medial layer. Glycosaminoglycan (GAG), collagen and elastin levels were measured using biochemical assays. Verhoeff Van Gieson-stained sections were imaged for elastin microstructural quantification. BAV-A had approximately 20