A thrombectomy apparatus for breaking up thrombus or other obstructive material in a lumen of a vascular graft or vessel. The apparatus includes a wire having a first configuration and a second deployed configuration, the wire having a straighter configuration in the first configuration. The wire is operatively connected to a motor for rotation of the wire to contact and break up the thrombus or other obstructive material. A blocking device at a distal portion of the apparatus is movable between a collapsed configuration and an expanded configuration, and is configured in the expanded configuration to block thrombus dislodged by rotation of the wire.