Background: The bicuspid aortic valve is one of the common congenital heart anomalies in adults. Although many studies have proved the coincidence between bicuspid aortic valve and the occurrence of ascending aortic dilation, seldom study has focused on the hemodynamic environments after the dilation already formed. Four numerical models of bicuspid aortic valve were constructed in this study, based on medical images, with different ascending aortic dilation levels. The diameters of ascending aortic are 3.5cm, 4.0cm, 4.5cm and 5.0cm, respectively; while, the size and the geometry of other parts are fixed. Then hemodynamics in these models was simulated numerically and the flow patterns and loading distributions were investigated. Aim of this study is to investigate the hemodynamic environment characteristics in the ascending aorta after dilation formed for the bicuspid aortic valve (BAV) patients.
Results: Hemodynamics environments in the dilated ascending aorta were simulated, with different level of dilation. As the diameter increases, the blood flow becomes more disturbing. The wall shear stress at the ascending aortic decreases while oscillatory shear index increases with the increase of diameter. The pressure at ascending aortic increases as the diameter increases. Moreover, all these hemodynamic parameters described above are asymmetrically distributed with the increase of ascending aortic diameter and more parts of aorta would be affected with the increasing ascending aorta diameters
Conclusions: The study revealed that the ascending aortic dilation levels can significantly influence the magnificent and distribution of the dynamics. There are altered flow patterns, pressure difference, WSS and OSI distribution features in bicuspid aortic valve patients with valvular dilation. As the extent of aortic dilatation increases, more parts of aorta like aortic arch should be paid more attention to when an individual is referred for surgery