A stapler for stapling a tubular structure to another structure. The stapler has an anvil which is expandable from a collapsed position to an expanded position. The stapler has a recess which receives at least a portion of the tubular structure and a shoulder which receives an everted end of the tubular structure. A first actuator moves the anvil relative to the shoulder for compressing the structures which are to be stapled together. A second actuator is used for driving the staples through the structures to be stapled together.