Abstract: A heart valve prosthesis which incorporates a substantially permanently implantable abutment structure which is surgically attached to a native heart valve annulus through utilization of a resilient metal substructure having an attachment portion which moves into engagement with a native heart annulus upon being released from a retracted orientation. The system employs a positioning instrument which locates the abutment structure and associated heart valve prosthesis at the proper location for releasing the attachment components. Mechanical heart valve components including an occluder function are removably attached to the abutment structure using sutures, such that the valve function itself may be subsequently replaced.