Determining the effect of congenital bicuspid aortic valves on aortic dissection using computational fluid dynamics

A normal aortic valve has three leaflets; however, 1- 2% of children are born with an aortic valve with two leaflets, referred to as congenital bicuspid aortic valves (BAV). Recent in vivo studies have shown that flow development past the bicuspid valves into the ascending aorta is markedly different from that past the normal tri-leaflet aortic valve. This difference may lead to the bicuspid valve having a higher rate of ascending aortic root dissection, a pathology that can potentially result in fatality. Using computational fluid dynamics we aim to evaluate the alterations in flow development in the ascending aorta with BAV compared to healthy tri-leaflet valves (TAV) and relate the alterations in flow-induced stresses with higher incidences of aortic dissection in patients with BAV. Simplified models based on the geometry and dimensions from published literature were developed. The preliminary results show that there is a difference in flow development between the BAV and the tri-leaflet valve. This is visible by the differences in wall shear stress and dynamic pressure distribution in the ascending aorta. The conclusion drawn from this is that there are marked differences in the ascending aortic flow development with BAV compared to that with TAV which may lead to dissection of the aortic arch.