Disclosed is an instrument for use in a procedure to effect anastomosis of a patient's bladder and urethra following a prostatectomy having a tube assembly, and an end effector assembly operably supported by the tube assembly. The end effector assembly includes a positioner assembly and an anchor driver assembly in operable mechanical communication with first and second rods of the tube assembly, so as to be actuable by movement of the first and the second rods with respect to a spine member.