Abstract: A stent-stabilizing device for controllably reducing the relative motion of a guide wire inside a passageway or lumen of a blood vessel catheter thereby restricting the relative motion of a stent or other object fitted thereto. The stent-stabilizing device comprises an elongated sheath, an expandable plug, and an elongated member. The sheath is preferably tubular in shape. The elongated member comprises an optional handle or grip. In another embodiment the elongated member and sheath are configured to provide a keyway system to prevent unwanted deployment of the plug.