A method and apparatus for anchoring a medical implant device after the device has been brought to rest at a desired position within a blood vessel or other body passageway. An anchor delivery system (22) is provided which houses one or more uniquely configured expandable anchors (28) which are connected to the medical implant device (10). The anchors (28) remain housed in a non expanded configuration until after the medical implant device (10) has come to rest in a desired position within the body, and then the anchors (28) are positively propelled through a body wall (12) from a first side to a second side where each anchor (28) expands outwardly on opposite sides of an anchor shaft (18). To positively propel the anchors (28), a drive shaft (50) extends back to a triggering unit (68) which, when activated, causes the drive shaft (50) to drive the anchor shafts (18) in a direction which results in propulsion of the anchors (28) through the body wall (12).