Apparatus for electrosurgical spine surgery

• US 6,283,961 B1
• Filed: 06/03/1999
• Issued: 09/04/2001
• Est. Priority Date: 07/16/1996
• Status: Expired due to Term

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Eggers, Philip E., Thapliyal, Hira V., Underwood, Ronald A., Davison, Terry S.
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US09/345,665
• Time in Patent Office: 824 Days
• Field of Search: 606/32, 606/34, 606/41, 606/46, 606/49, 606/50, 607/99, 607/105, 607/113, 604/35, 604/114
• US Class Current: 606/41
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 18/149 bow shaped or with rotatable body at cantilever end, e.g. for resectoscopes, or coagulating rollers
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00097 one of the thermometric elements being an electrode or the heating element
• CPC Class Codes: A61B 2017/00101 using an array of thermosensors
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00119 : with metal oxide nitride
• CPC Class Codes: A61B 2018/0016 : Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00178 : Electrical connectors
• CPC Class Codes: A61B 2018/00196 : reciprocating lengthwise
• CPC Class Codes: A61B 2018/00327 : Ear, nose or throat
• CPC Class Codes: A61B 2018/00392 : Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00434 : Neural system
• CPC Class Codes: A61B 2018/00505 : Urinary tract
• CPC Class Codes: A61B 2018/00577 : Ablation
• CPC Class Codes: A61B 2018/00583 : Coblation, i.e. ablation using a cold plasma
• CPC Class Codes: A61B 2018/00642 : with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/0066 : without feedback, i.e. open loop control
• CPC Class Codes: A61B 2018/00678 : upper
• CPC Class Codes: A61B 2018/00702 : Power or energy
• CPC Class Codes: A61B 2018/00726 : Duty cycle
• CPC Class Codes: A61B 2018/00761 : Duration
• CPC Class Codes: A61B 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00797 : measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00821 : measured by a thermocouple
• CPC Class Codes: A61B 2018/00827 : Current
• CPC Class Codes: A61B 2018/00875 : Resistance or impedance
• CPC Class Codes: A61B 2018/00886 : Duration
• CPC Class Codes: A61B 2018/1213 : creating an arc
• CPC Class Codes: A61B 2018/124 : switching the output to different electrodes, e.g. sequentially
• CPC Class Codes: A61B 2018/1253 : monopolar
• CPC Class Codes: A61B 2018/126 : bipolar
• CPC Class Codes: A61B 2018/1273 : including multiple generators in one device
• CPC Class Codes: A61B 2018/1467 : using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1472 : for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2018/1497 : Electrodes covering only part of the probe circumference
• CPC Class Codes: A61B 2018/162 : located on the probe body
• CPC Class Codes: A61B 2018/165 : Multiple indifferent electrodes
• CPC Class Codes: A61B 2090/378 : using ultrasound
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 2218/007 : Aspiration
• CPC Class Codes: A61F 2/2493 : Transmyocardial revascularisation [TMR] devices
• CPC Class Codes: A61M 25/0133 : Tip steering devices
• CPC Class Codes: A61M 25/0147 : with movable mechanical means, e.g. pull wires
• CPC Class Codes: A61M 25/0158 : with magnetic or electrical means, e.g. by using piezo materials, electroactive polymers, magnetic materials or by heating of shape memory materials

Abstract

The present invention provides systems and methods for selectively applying electrical energy to a target location within of a patient'"'"'s body, particularly including tissue in the spine. The present invention applies high frequency (RF) electrical energy to one or more electrode terminals in the presence of electrically conductive fluid to remove, contract or otherwise modify the structure of tissue structures. In one aspect of the invention, a method is provided for treating herniated discs within a patient'"'"'s spine by applying sufficient electrical energy to the disc tissue to reduce a volume of the disc, thereby relieving pressure on a spinal nerve. In one embodiment, the high frequency voltage is sufficient to ablate a portion of the nucleus pulposis, either the extruded portion outside of the annulus or a portion or all of the pulposis within the annulus. In another embodiment, the electrode terminal is advanced into the annulus and sufficient high frequency voltage is applied to contract or shrink the collagen fibers within the nucleus pulposis. This causes the pulposis to shrink and withdraw from its impingement on the spinal nerve.

Claims

1. An electrosurgical apparatus for treating tissue within a patient'"'"'s spine comprising:

a shaft having a proximal end portion and a distal end portion sized to fit within an intervertebral disc in the patient'"'"'s spine;

an electrode terminal on the distal end portion of the shaft;

a return electrode;

an insulating member positioned between the return electrode and the electrode terminal, the return electrode being sufficiently spaced from the electrode terminal to minimize direct contact between the return electrode and a body structure in or on the disc when the electrode terminal is positioned in close proximity or in partial contact with the body structure; and

means for applying a high frequency voltage difference between the electrode terminal and the return electrode to reduce a volume of the disc to relieve pressure on a spinal nerve.

2. The apparatus of claim 1 further comprising means for applying sufficient high frequency voltage between the electrode terminal and the return electrode to ablate a portion of the nucleus pulposis within the disc.

3. The apparatus of claim 1 further comprising means for applying sufficient high frequency voltage between the electrode terminal and the return electrode to contract collagen fibers within the nucleus pulposis within the disc.

4. The apparatus of claim 1 further comprising a fluid delivery element defining a fluid path in electrical contact with the return electrode and the electrode terminal to generate a current flow path between the return electrode and the electrode terminal.

5. The apparatus of claim 4 wherein the fluid delivery element comprises a fluid tube extending along an outer surface of the shaft, the tube having an inlet positioned proximal to the return electrode, wherein the return electrode is spaced proximally from the electrode terminal.

6. The apparatus of claim 4 wherein the fluid delivery element comprises a fluid supply instrument separate from the shaft.

7. The apparatus of claim 1 wherein the distal end portion of the shaft has a diameter less than about 2.0 mm.

8. The apparatus of claim 1 wherein the return electrode forms a portion of the shaft.

9. The apparatus of claim 1 wherein the electrode terminal comprises an electrode array disposed near the distal end portion of the shaft, the array including a plurality of electrically isolated electrode terminals disposed over a contact surface.

10. The apparatus of claim 1 wherein the electrode terminal comprises a single active electrode disposed near the distal end portion of the shaft.

11. The apparatus of claim 1 further comprising a fluid aspiration element for aspirating fluid from a region around the electrode terminal.

12. The apparatus of claim 11 wherein the fluid aspiration element comprises a suction lumen extending through the shaft, the suction lumen having an inlet at a distal tip of the shaft adjacent the electrode terminal.

13. The apparatus of claim 12 further comprising an aspiration electrode at or near the inlet of the suction lumen for ablating tissue fragments aspirated into the suction lumen.

14. The apparatus of claim 13 wherein the aspiration electrode comprises a mesh electrode having one or more openings positioned across the inlet of the suction lumen.

15. The apparatus of claim 14 wherein the mesh electrode and the electrode terminal are electrically coupled to each other to form a single electrode.

16. The apparatus of claim 14 wherein the mesh electrode comprises a material having a different voltage potential than the electrode terminal.

17. The apparatus of claim 1 wherein the distal end portion of the shaft has an active side and a substantially planar non-active side opposing the active side, the electrode terminal being disposed on the active side and being insulated from the non-active side.

18. The apparatus of claim 17 wherein the distal end portion of the shaft has a thickness from the active side to the non-active side of less than 2 mm.

19. The apparatus of claim 1 further comprising an electrically insulating support member extending from the distal end portion of the shaft, the electrode terminal being mounted to the support member.

20. The apparatus of claim 19 wherein the support member is an insulating wafer having a tissue treatment surface disposed at or near the distal end portion of the shaft, the insulating wafer having at least one conductive strip forming the electrode terminal, the apparatus further comprising an electrical connector extending from the conductive strip to the proximal end portion of the shaft for coupling the electrode terminal to the applying means.

21. The apparatus of claim 20 further comprising a plurality of conductive strips on the insulating wafer forming an array of electrically isolated terminals on the tissue treatment surface.

22. The apparatus of claim 21 wherein the conductive strips are substantially linear and parallel to each other, the wafer including a plurality of ridges extending from the tissue treatment surface, and the conductive strips being formed on the ridges.

23. The apparatus of claim 20 wherein the insulating wafer comprises ceramic and the conductive strip comprises tungsten.

24. An electrosurgical apparatus for treating tissue within a patient'"'"'s spine comprising:

a shaft having a proximal end portion and a distal end portion sized to fit within an intervertebral disc in the patient'"'"'s spine;

an electrode terminal on the distal end portion of the shaft;

a return electrode;

a fluid delivery element defining a fluid path in electrical contact with the return electrode and the electrode terminal to generate a current flow path between the return electrode and the electrode terminal, wherein the fluid delivery element comprises a fluid tube extending a long an outer surface of the shaft, the tube having an inlet positioned proximal to the return electrode, wherein the return electrode is spaced proximally from the electrode terminal; and

means for applying a high frequency voltage difference between the electrode terminal and the return electrode to reduce a volume of the disc to relieve pressure on a spinal nerve.

25. The apparatus of claim 24 further comprising means for applying sufficient high frequency voltage between the electrode terminal and the return electrode to ablate a portion of the nucleus pulposis within the disc.

26. The apparatus of claim 24 further comprising means for applying sufficient high frequency voltage between the electrode terminal and the return electrode to contract collagen fibers within the nucleus pulposis within the disc.

27. The apparatus of claim 24 wherein the distal end portion of the shaft has a diameter less than about 2.0 mm.

28. The apparatus of claim 24 wherein the return electrode forms a portion of the shaft.

29. The apparatus of claim 24 further including an insulating member positioned between the return electrode and the electrode terminal, the return electrode being sufficiently spaced from the electrode terminal to minimize direct contact between the return electrode and a body structure on or in the disc when the electrode terminal is positioned in close proximity or in partial contact with the body structure.

30. The apparatus of claim 24 wherein the electrode terminal comprises an electrode array disposed near the distal end portion of the shaft, the array including a plurality of electrically isolated electrode terminals disposed over a contact surface.

31. The apparatus of claim 24 wherein the electrode terminal comprises a single active electrode disposed near the distal end portion of the shaft.

32. The apparatus of claim 24 further comprising a fluid aspiration element for aspirating fluid from a region around the electrode terminal.

33. The apparatus of claim 32 wherein the fluid aspiration element comprises a suction lumen extending through the shaft, the suction lumen having an inlet at a distal tip of the shaft adjacent the electrode terminal.

34. The apparatus of claim 32 further comprising an aspiration electrode at or near the inlet of the suction lumen for ablating tissue fragments aspirated into the suction lumen.

35. The apparatus of claim 34 wherein the aspiration electrode comprises a mesh electrode having one or more openings positioned across the inlet of the suction lumen.

36. The apparatus of claim 35 wherein the mesh electrode and the electrode terminal are electrically coupled to each other to form a single electrode.

37. The apparatus of claim 35 wherein the mesh electrode comprises a material having a different voltage potential than the electrode terminal.