A surgical instrument for being endoscopically or laparoscopically inserted through a cannula of a trocar into an insufflated body cavity or lumen (“surgical site”) for simultaneous stapling and severing of tissue including gripping surfaces on inner surfaces of an upper and lower jaw that enhance use as a grasping instrument to preposition tissue prior to performing a stapling and severing procedure. An illustrative version advantageously includes a separate closure trigger and closure mechanism that facilitates use as a grasper without the possibility for inadvertent firing (i.e., stapling and severing).