A surgical instrument comprising: a handle assembly (12, 12')having a proximal end and a distal end; an elongate shaft extending from the distal end of the handle assembly along a central longitudinal axis, the elongate shaft having a distal end opposite the handle assembly (12, 12'); and an end effector assembly disposed at the distal end of the elongate shaft; wherein the handle assembly (12, 12') has an in-line configuration extending generally linearly from the proximal end to the distal end thereof; and wherein the handle assembly (12, 12') further comprises: a handle body; and a linkage mechanism comprising: a trigger pivotably coupled to the handle body and pivotable between an open position in which the end effector assembly is in an open state, and a toggle position in which the end effector assembly is locked in a closed state; an actuation link pivotably coupled to the trigger and extending generally proximally within the handle body; and an actuation shaft pivotably coupled to the actuation link and longitudinally slidable with respect to the elongate shaft responsive to pivotal movement of the trigger, the actuation shaft operatively coupled to the end effector assembly; characterized in that the handle body comprises a first aperture and a second aperture generally diametrically opposed to the first aperture; and the trigger has a first actuation surface and a second actuation surface opposite the first actuation surface, and wherein the trigger is alternately pushable from the first aperture to the second aperture such that the first actuation surface of the trigger protrudes from the first aperture of the handle body when the trigger is in the open position and the second actuation surface of the trigger protrudes from the second aperture of the handle body when the trigger is in the toggle position. a handle assembly (12, 12')having a proximal end and a distal end; an elongate shaft extending from the distal end of the handle assembly along a central longitudinal axis, the elongate shaft having a distal end opposite the handle assembly (12, 12'); and an end effector assembly disposed at the distal end of the elongate shaft; wherein the handle assembly (12, 12') has an in-line configuration extending generally linearly from the proximal end to the distal end thereof; and wherein the handle assembly (12, 12') further comprises: a handle body; and a linkage mechanism comprising: a trigger pivotably coupled to the handle body and pivotable between an open position in which the end effector assembly is in an open state, and a toggle position in which the end effector assembly is locked in a closed state; an actuation link pivotably coupled to the trigger and extending generally proximally within the handle body; and an actuation shaft pivotably coupled to the actuation link and longitudinally slidable with respect to the elongate shaft responsive to pivotal movement of the trigger, the actuation shaft operatively coupled to the end effector assembly; characterized in that the handle body comprises a first aperture and a second aperture generally diametrically opposed to the first aperture; and the trigger has a first actuation surface and a second actuation surface opposite the first actuation surface, and wherein the trigger is alternately pushable from the first aperture to the second aperture such that the first actuation surface of the trigger protrudes from the first aperture of the handle body when the trigger is in the open position and the second actuation surface of the trigger protrudes from the second aperture of the handle body when the trigger is in the toggle position. a handle body; and a linkage mechanism comprising: a trigger pivotably coupled to the handle body and pivotable between an open position in which the end effector assembly is in an open state, and a toggle position in which the end effector assembly is locked in a closed state; an actuation link pivotably coupled to the trigger and extending generally proximally within the handle body; and an actuation shaft pivotably coupled to the actuation link and longitudinally slidable with respect to the elongate shaft responsive to pivotal movement of the trigger, the actuation shaft operatively coupled to the end effector assembly; a trigger pivotably coupled to the handle body and pivotable between an open position in which the end effector assembly is in an open state, and a toggle position in which the end effector assembly is locked in a closed state; an actuation link pivotably coupled to the trigger and extending generally proximally within the handle body; and an actuation shaft pivotably coupled to the actuation link and longitudinally slidable with respect to the elongate shaft responsive to pivotal movement of the trigger, the actuation shaft operatively coupled to the end effector assembly; characterized in that the handle body comprises a first aperture and a second aperture generally diametrically opposed to the first aperture; and the trigger has a first actuation surface and a second actuation surface opposite the first actuation surface, and wherein the trigger is alternately pushable from the first aperture to the second aperture such that the first actuation surface of the trigger protrudes from the first aperture of the handle body when the trigger is in the open position and the second actuation surface of the trigger protrudes from the second aperture of the handle body when the trigger is in the toggle position.