Abstract 10921: Wall Stress of Ascending Thoracic Aortic Aneurysm versus Normal Aorta: Towards Defining Wall-stress Based Thresholds for Aneurysm Intervention

IntroductionAneurysm wall stress may better predict rupture/dissection risk than diameter. We hypothesize aTAA have elevated wall stress compared to normal ascending aorta, yet correlation of aTAA wall stress with diameter is weak.Methods33 patients (age 68.2±7.7 years, n=33 men) underwent aTAA resection. Mean pre-op aTAA diameter was 52.2±4.7mm. 23 normal ascending aorta (AscAo) (age 53±11.8 years, n=13 men, n=10 women) with diameter 32.2±3.2mm, were obtained from rejected donor hearts. ATAA/AscAo specimens underwent micro-CT for wall thickness/geometry. Hyperelastic material model with patient-averaged properties from biaxial stretch testing was assigned to the models. Finite element simulations using LS-DYNA software loaded models to physiologic pressure (120/80mmHg) for wall stress analysis.ResultsATAA vs AscAo peak first principal wall stresses (FPS, circumferential direction) were 225.2±85.9kPa vs 152.2±36.9kPa (p