An end effector for use with a surgical suturing instrument, the end effector comprising: a first jaw member and a second jaw member, the first jaw member being movable relative to the second jaw member between an open position and an approximated position for grasping tissue, each of the first and second jaw members defining a knife slot, a first needle slot (39a, 39c, 39e), and a second needle slot (39b, 39d, 39f), the knife slot, the first needle slot (39a, 39c, 39e), and the second needle slot (39b, 39d, 39f) extending along a longitudinal axis of the end effector; a knife assembly configured to advance through the first jaw member and the second jaw member, the knife assembly including an upper knife flange, a lower knife flange, and a cutting element between the upper knife flange and the lower knife flange; and an upper assembly including: an upper bellcrank pivotably coupled to the upper knife flange; a first needle pivotably coupled to a first end of the upper bellcrank, the first needle defining a first aperture and being configured to advance through the first needle slot (39a, 39c, 39e); a first suture (Sa) passing through the first aperture; a second needle pivotably coupled to a second end of the upper bellcrank, the second needle defining a second aperture and being configured to advance through the second needle slot (39b, 39d, 39f); and a second suture (Sb) passing through the second aperture; preferably wherein the first needle slot (39a, 39c, 39e) and the second needle slot (39b, 39d, 39f) are located on opposite sides of the knife slot. a first jaw member and a second jaw member, the first jaw member being movable relative to the second jaw member between an open position and an approximated position for grasping tissue, each of the first and second jaw members defining a knife slot, a first needle slot (39a, 39c, 39e), and a second needle slot (39b, 39d, 39f), the knife slot, the first needle slot (39a, 39c, 39e), and the second needle slot (39b, 39d, 39f) extending along a longitudinal axis of the end effector; a knife assembly configured to advance through the first jaw member and the second jaw member, the knife assembly including an upper knife flange, a lower knife flange, and a cutting element between the upper knife flange and the lower knife flange; and an upper assembly including: an upper bellcrank pivotably coupled to the upper knife flange; a first needle pivotably coupled to a first end of the upper bellcrank, the first needle defining a first aperture and being configured to advance through the first needle slot (39a, 39c, 39e); a first suture (Sa) passing through the first aperture; a second needle pivotably coupled to a second end of the upper bellcrank, the second needle defining a second aperture and being configured to advance through the second needle slot (39b, 39d, 39f); and an upper bellcrank pivotably coupled to the upper knife flange; a first needle pivotably coupled to a first end of the upper bellcrank, the first needle defining a first aperture and being configured to advance through the first needle slot (39a, 39c, 39e); a first suture (Sa) passing through the first aperture; a second needle pivotably coupled to a second end of the upper bellcrank, the second needle defining a second aperture and being configured to advance through the second needle slot (39b, 39d, 39f); and a second suture (Sb) passing through the second aperture; preferably