An endovascular stapler (100) for securing an endograft to a vessel is disclosed. The stapler has a staple housing (104), an actuating mechanism (148) and an expansion mechanism (126). The staple housing (104) has a plurality of staple cartridges (128) adapted for storing at least one staple (180) therein. The staple cartridges (128) have an exit area (130) for discharging at least one of the staples (180) therethrough. The actuating assembly (148) is adapted for actuating the plurality of staple cartridges (128) to discharge the at least one staple through the exit area. The expansion mechanism (126) is in operative association with staple cartridges (128). The expansion mechanism (126) is operative for pushing the exit area (130) against the endograft when discharging the at least one staple therethrough.