A method and an apparatus for anchoring a medical implant device within a blood vessel or other body passageway are described herein. An anchor delivery system houses one or more expandable anchors connected to the medical implant device. The anchors remain housed in a non-expanded configuration until the medical implant device has been placed in a desired position within the body, and then the anchors are propelled through a body wall where each anchor expands outwardly from an anchor shaft. In one configuration, each anchor is formed as a compressible closed loop which extends outwardly from an anchor shaft and loops back to cross over and extend beyond the anchor shaft. To propel the anchors, a drive shaft is connected to a triggering unit which, when activated, causes the drive shaft to drive the anchor shafts in a direction such that the anchors are propelled through the body wall.