Bipolar resectoscope

A bipolar resectoscope (1) comprising

• a shaft (2, 2′) having a distal end (7) and a proximal end (9), a passive electrode terminal disposed at the proximal end (9) of the shaft (2, 2′);
• a working element (3) mountable in the shaft (2, 2′), the working element having a proximal end (11) with an active electrode terminal, the working element (3) having an optical guide tube (10) to accommodate an optical unit (6) that can be inserted in the working element (3);
• an insulating insert (8, 8′) made of an electrically non-conductive material being disposed at the distal end (7) of the shaft (2, 2′) and having:
• a longitudinal axis (33),
• a distal end (35, 35′) facing away from the shaft (2, 2′) and exposed from the shaft (2, 2′), and
• an inlet area (36, 36′) arranged at the distal end (35, 35′) of the insulating insert (8, 8′) and disposed below the longitudinal axis (33) of the insulating insert (8, 8′) in a vertical direction;
• a passive neutral electrode (5, 5′) having an exposed electrically conductive area arranged at the distal end (35, 35′) of the insulating insert (8, 8′), the passive neutral electrode (5, 5′) being electrically connected to the passive electrode terminal at the proximal end (9) of the shaft (2, 2′);
• and
• an active cutting electrode (4) that can be arranged in the working element (3) in a longitudinally displaceable manner, the longitudinally displaceable active cutting electrode (4) having opposite proximal and distal ends (19, 23), the proximal end (19) of the active cutting electrode (4) being connected to the active electrode terminal at the proximal end (11) of the working element (3), the distal end (23) of the active cutting electrode (4) being arranged in the inlet area (36, 36′) at the distal end (35, 35′) of the insulating insert (8, 8′), the distal end (23) of the active cutting electrode (4) forming a fork (26) having two parallel electrically conductive contact tubes (24) that are electrically isolated from a remainder of the fork (26), the active cutting electrode (4) further having a cutting loop (25) extending distally from the electrically conductive contact tubes (24) wherein:
• an area of the passive neutral electrode (5, 5′) is exposed toward the longitudinal axis (33) of the insulating insert (8, 8′) and forms a roof section (32, 32′) of the insulating insert (8, 8′), the roof section (32, 32′) being continuously electrically conductive toward the longitudinal axis,
• the roof section (32, 32′) is disposed offset transversely from the longitudinal axis (33) of the insulating insert (8, 8′) in the vertical direction above the inlet area (36) and extends in a direction of the longitudinal axis (33) over the inlet area (36) of the insulating insert (8),
• the inlet area (36, 36′) of insulating insert (8, 8′) has an inside wall (38, 38′) with two exposed electrically conductive contact surfaces (39, 39′) of the passive neutral electrode (5, 5′) facing each other and running parallel to the longitudinal axis (33), the electrically conductive contact surfaces (39, 39′) of the passive neutral electrode (5, 5′) are respectively in metallic contact with the contact tubes (24) of the fork (26) of the active cutting electrode (4).