A surgical instrument includes a hollow tubular member having a closed distal working end, a proximal end and an outer surface, with an opening in a side wall at or adjacent the distal working end. The instrument includes a first electrical insulation layer disposed on at least part of the outer surface of the hollow tubular member, a first electrode disposed on an outer surface of the first electrical insulation layer, and a second electrode disposed on the outer surface of the first electrical insulation layer. The first and second electrodes are electrically isolated from each other, and each includes an active segment and an inactive segment. The active segments of the first and second electrodes are disposed respectively on opposing sides of the hollow tubular member preferably within about 3.0 mm of the opening in the side wall of the hollow tubular member.