An end effector includes first and second jaws, first and second buttresses,and anultrasonic blade. The first jaw includes a fastener cartridge having a firsttissue contactingsurface and a plurality of fasteners arranged in rows parallel to alongitudinal axis of the firstjaw. The first buttress is attached to the first tissue contacting surface andthe second buttressis attached to a second tissue contracting surface of the second jaw. Thefirst and secondjaws are movable relative to one another and are configured to grasp tissuetherebetween.The ultrasonic is activatable to weld the first buttress to the secondbuttress and tosubsequently cut the welded first and second buttresses and tissue graspedbetween the firstand second jaws.
