Bipolar electrosurgical instrument for cutting and sealing tubular tissue structures

• US 5,891,141 A
• Filed: 04/23/1998
• Issued: 04/06/1999
• Est. Priority Date: 09/02/1997
• Status: Expired due to Term

• Current Assignee: Gyrus ACMI, Inc. (Olympus Corporation)
• Original Assignee: Everest Medical Corp. (Olympus Corporation)
• Inventors: Rydell, Mark A.
• Primary Examiner(s): Dawson, Glenn K.
• Application Number:
  US09/065,242
• Time in Patent Office: 348 Days
• Field of Search: 606/32, 606/34, 606/37-42, 606/45-52, 606/151, 606/157, 606/167, 606/205-211
• US Class Current: 606/45
• CPC Class Codes: A61B 18/1442 Probes having pivoting end effectors, e.g. forceps
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00404 Blood vessels other than those in or around the heart
• CPC Class Codes: A61B 2018/00601 Cutting
• CPC Class Codes: A61B 2018/126 bipolar

Abstract

An electrosurgical instrument for cutting and coagulating tubular tissue structures, especially tubular ones, includes a pair of spaced-apart electrodes that are stationarily mounted at the distal end of an elongated tubular barrel. A hook-shaped cutting member has an incline segment thereon for cooperating with a ramp formed at the distal end of the instrument. A tubular body structure to be severed is first brought into contact with electrodes and subjected to a RF current sufficient to coagulate and seal the same. Actuation of a lever on the instrument'"'"'s handle causes the hook-shaped cutting member to deflect into a space containing the tissue structure and with continued actuation in a proximal direction causing a cutting edge on the hook of the cutting member to pass through and sever the tissue structure.

Claims

1. An electrosurgical instrument for cutting and coagulating selected tissue structures comprising:

(a) an elongated tubular barrel having a proximal end, a distal end and a lumen extending therebetween;

(b) a handle attached to the proximal end of the barrel;

(c) a pair of resilient, metal wire electrodes, each having a pair of legs joined at one end thereof to form a generally U-shape;

(d) an electrode support member affixed to the distal end of the barrel for supporting at least one of the pair of electrodes in parallel, spaced-apart, cantilevered relation to the other of the pair of electrodes at the distal end of the barrel with a predetermined gap therebetween, the support member including at least one pair of bores, at least one of the at least one pair of bores communicating with the lumen of the barrel for receiving the legs of the at least one pair of electrodes therein, and a longitudinal slot extending transverse to planes in which the legs of the pair of electrodes reside midway between the pairs of legs of the electrodes;

(e) a cutting member disposed in the slot and longitudinally movable therein, one of the cutting member and the slot including an inclined segment;

(f) actuator means disposed on the handle and coupled to the cutting member for imparting reciprocal longitudinal translation of the cutting member where the longitudinal translation engages the inclined segment on the one of the cutting member and the slot with an edge surface of the other of the cutting member and the slot to deflect the cutting member between the legs of the electrodes; and

(g) conductor means extending through the handle, the lumen of the barrel and the at least one of the at least one pair of bores and adapted to connect the pair of electrodes to a voltage source.

2. The electrosurgical instrument as in claim 1 wherein the predetermined gap is adapted to be less than the thickness of the selected tissue structures to be cut and coagulated with the pair of electrodes gripping the selected tissue structures when inserted between the pair of electrodes.

3. The electrosurgical instrument as in claim 1 wherein the cutting member is hook-shaped.

4. The electrosurgical instrument as in claim 3 wherein the hook-shaped cutting member is movable from a first position where the hook-shaped cutting member resides out of the gap to a second position in the gap and abutting the electrode support member upon actuation of the actuator means.

5. The electrosurgical instrument as in claim 3 wherein a concave portion of the hook-shaped cutting member is beveled to create a cutting edge.

6. The electrosurgical instrument as in claim 1 wherein the conductor means includes a control switch.

7. The electrosurgical instrument as in claim 3 wherein the actuator means comprises a finger operable member and a generally rigid rod coupling the finger operable member to the hook-shaped cutting member.

8. The electrosurgical instrument as in claim 7 wherein the hook-shaped cutting member comprises a shank portion terminating at a distal end in a hook portion and at a proximal end in the inclined segment, the generally rigid rod being connected to an end of the inclined segment, the hook portion including a sharpened cutting edge.

9. The electrosurgical instrument as in claim 2 wherein movement of the actuator means in a proximal direction engages an edge on the cutting member with a ramp surface in the slot for forcing the cutting member into the gap between the pair of electrodes and against the tissue structures being gripped therebetween.

10. The electrosurgical instrument as in claim 2 wherein movement of the actuator means in a proximal direction engages an inclined segment on the cutting member with an edge of the slot for forcing the cutting member into the gap between the pair of electrodes and against the tissue structure being gripped therebetween.

11. An electrosurgical instrument for cutting and coagulating tubular tissue structures comprising:

(a) an elongated tubular barrel having a proximal end, a distal end and a lumen extending therebetween;

(b) a handle attached to the proximal end of the barrel;

(c) a pair of metal wire electrodes;

(d) an electrode support member affixed to the distal end of the barrel for supporting at least one of the pair of electrodes in parallel, spaced-apart, cantilevered relation at the distal end of the barrel, the support member including at least one bore communicating with the lumen of the barrel for receiving the at least one pair of electrodes therein, and a longitudinal slot extending transverse to a plane in which the pair of electrodes reside midway between the electrodes;

(e) a hook-shaped cutting member disposed in the slot and longitudinally movable therein, one of the hook-shaped cutting member and the slot including an inclined segment;

(f) actuator means disposed on the handle and coupled to the hook-shaped cutting member for imparting reciprocal longitudinal translation and transverse movement of the hook-shaped cutting member where the longitudinal translation engages the inclined segment on the one of the cutting member and the slot with an edge surface of the other of the cutting member and the slot to deflect the cutting member between the pair of electrodes; and

(g) conductor means extending through the handle, the lumen of the barrel and the at least one bore, the conductor means adapted to connect the electrodes to a voltage source.

12. The electrosurgical instrument as in claim 11 wherein the hook-shaped cutting member comprises a shank portion terminating at a distal end in a hook portion and at a proximal end in the inclined segment, a generally rigid rod being connected to an end of the inclined segment, the hook portion including a sharpened cutting edge.

13. The electrosurgical instrument as in claim 12 wherein the metal wire electrodes are rectilinear.

14. The electrosurgical instrument as in claim 13 wherein the hook-shaped cutting member is movable from a first position where the hook-shaped cutting member overlays the plane by a predetermined gap distance to a second position where the hook-shaped cutting member intersects the plane upon actuation of the actuator means.

15. The electrosurgical instrument as in claim 14 wherein a concave portion of the hook-shaped cutting member is beveled to create a cutting edge.

16. The electrosurgical instrument as in claim 13 wherein movement of the actuator means in a proximal direction engages an inclined segment of the hook-shaped cutting member with an edge of the slot for forcing the cutting member into a space between the pair of electrodes and against a tubular tissue structure disposed between the pair of electrodes and the hook-shaped cutting member.

17. The electrosurgical instrument as in claim 13 wherein movement of the actuator means in a proximal direction engages an edge on the hook-shaped cutting member with an inclined segment of the slot for forcing the cutting member into a space between the pair of electrodes and against a tubular tissue structure disposed between the pair of electrodes and the hook-shaped cutting member.

18. The electrosurgical instrument as in claim 11 and further including an outer sheath concentrically disposed on and slidable along the tubular barrel, the sheath having a proximal end and a distal end and wherein one of the pair of electrodes includes a ramp surface thereon whereby sliding the distal end of the sheath against the ramp surface on the one of the pair of electrodes displaces the one of the pair of electrodes toward the other of the pair of electrodes.

19. The electrosurgical instrument as in claim 18 and further including actuator means on the handle operatively coupled to said sheath for imparting reciprocal motion thereto.