A loading unit configured for releasable engagement with a surgical instrument, the loading unit comprising: a body portion defining a longitudinal axis, a proximal portion of the body portion configured for releasable engagement with an endoscopic portion of the surgical instrument a pair of jaw members extending generally distally from the body portion, each of the jaw members being longitudinally curved with respect to the longitudinal axis, at least one of the jaw members being movable with respect to the other between an open position and an approximated position for engaging body tissue therebetween, the pair of jaw members including a first jaw member and a second jaw member, the first jaw member including a channel with a longitudinally-extending slot therein and a drive assembly disposed at least partially within the body portion and being longitudinally translatable with respect to the body portion the drive assembly having a drive bar with a lower portion that is configured and dimensioned to travel at least partially within the longitudinally-extending slot of the channel.
