An introducer for an expandable endovascular prosthesis (20) having a self a self-expanding stent (21) includes a proximal prosthesis positioning mechanism (3) that has a retention device (10) to retain the self-expanding stent and a control member (22, 24, 66) to selectively release the retention device from the prosthesis. The retention device includes an opening forming a tapered cavity. The control member includes a plurality of loops (66) coupled to the prosthesis and a trigger wire (22). The trigger wire passes through a first aperture (62) of the retention device, through the plurality of loops, and through and a second aperture (64) of the retention device to retain the loops.
