The imperfect hemodymamics and non-endothelialized surface of the BT shunt and RV-PA conduit can be improved by utilizing a shape that has more uniform flow and lower shear stress. Accordingly, the shunt will have an acute takeoff angle with a fluted inlet portion that eliminates fluid separation and maintains the shear stress within or near the physiologic range. The distal aspect of the shunt may be fluted in one or both directions along the pulmonary artery to improve the flow transition and reduce the shear forces on the posterior wall the pulmonary artery. An autologous umbilical vein may be used as the shunt with fluted proximal and distal portions with an autologous endothelialized surface to minimize platelet deposition and thrombus formation. The umbilical vein shunt may have an external support for diameter constraint and maintaining the hemodynamically optimized fluted design.