A trigger wire release mechanism is disclosed that includes a control member for selectively releasing a trigger wire (22, 44) from a prosthesis retaining device. The control member includes an elongate body member (36) and a guide member (24, 25, 93, 94) slidably disposed on the elongate body member. The trigger wire 1 (22, 44) includes a distal end coupled to the prosthesis retaining device and a proximal end coupled to the guide member. The guide member (24, 25, 93, 94) can be moved from a distal end of the elongate body (36) to a proximal end of the elongate body, thereby disengaging the trigger wire (22, 44) from the retaining device. The control member may include a locking mechanism (120) for limiting the axial position of the guide member (24, 25, 93, 94) along the elongate body member (36). A prosthesis control member (81) is also disclosed. The prosthesis control member (81) is adapted to control the position of the prosthesis during deployment.