Apparatus and methods are described for regulating blood flow in an ascending aorta of a subject including inserting a device (20) into the ascending aorta. When in a deployed state, the device defines an inner surface (24) that defines a conduit (26) through the device, at least a portion (25) of the inner surface diverging, such that a cross-sectional area of the conduit at the downstream end (34) of the diverging portion is greater than a cross-sectional area of the conduit at the upstream end (30) of the diverging portion. The device is deployed within a longitudinal portion of the ascending aorta, such that blood flow through the portion of the ascending aorta, via any flow path other than through the conduit, is less than 20 percent of total blood flow through the portion of the ascending aorta. Other applications are also described.
