A medical instrument comprises a housing and an elongated sheath configured to be attached to the housing. The elongated sheath includes opposed distal end and proximal end along a longitudinal axis. An end effector is configured to be attached to the distal end of the elongated sheath. The end effector includes a pair of grasps. A direction changer is used to change a direction of the end effector with respect to the distal end of the elongated sheath. A first drive shaft movable in the elongated sheath in ganged relation for opening and closing movement of the pair of grasps. A second drive shaft movable in the elongated sheath in ganged relation for angular movement of the end effector by the direction changer with respect to the elongated sheath. An operating member is configured to actuate the second drive shaft between a bent positions and a neutral position.