A vascular device for reducing blood flow in a first vessel or a first graft to enable increased blood flow in a second vessel or second graft. The vascular device includes a support structure having a proximal portion, a distal portion and an intermediate portion, the support structure movable from a reduced profile insertion position to an expanded placement position. A covering material is supported by the structure, the intermediate portion in the expanded position having a transverse dimension less than a transverse dimension of the proximal and distal portions to restrict blood flow through the device and thereby increase blood flow to the second vessel or second graft. A method or reducing blood flow in one vessel or graft and increasing blood flow in another vessel or graft is also disclosed.
