Systems and methods for electrosurgical spine surgery

• US 6,540,741 B1
• Filed: 10/04/1999
• Issued: 04/01/2003
• Est. Priority Date: 07/16/1996
• Status: Expired due to Fees

• 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:
  US09/412,103
• Time in Patent Office: 1,275 Days
• Field of Search: 606/32, 606/34, 606/41, 606/49, 606/50, 607/99, 607/105, 607/113, 604/35, 604/114
• US Class Current: 606/32
• 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. A method for treating an intervertebral disc within a patient'"'"'s spine, comprising:

positioning at least one active electrode terminal within close proximity of the disc; and

applying a high frequency voltage between the at least one active electrode terminal and a return electrode, the voltage being sufficient to remove a portion of a nucleus pulposus to reduce a volume of the disc.

2. The method of claim 1, further comprising:

introducing the at least one active electrode terminal into the nucleus pulposus via an opening in an annulus fibrosus of the disc.

3. The method of claim 1, wherein an extruded portion of the nucleus pulposus lies external to an annulus fibrosus of the disc, and the method further comprises positioning the at least one active electrode terminal adjacent to or within the extruded portion of the nucleus pulposus.

4. The method of claim 1, further comprising:

delivering electrically conductive fluid between the at least one active electrode terminal and the nucleus pulposus tissue.

5. The method of claim 4, further comprising:

positioning the return electrode within the electrically conductive fluid, wherein the electrically conductive fluid completes a current flow path between the at least one active electrode terminal and the return electrode.

6. The method of claim 4, further comprising:

applying sufficient voltage to the at least one active electrode terminal in the presence of the electrically conductive fluid to vaporize at least a portion of the electrically conductive fluid at a location between the at least one active electrode terminal and the nucleus pulposus tissue.

7. The method of claim 6, further comprising:

accelerating charged particles from the vaporized electrically conductive fluid to the nucleus pulposus tissue to cause dissociation of the molecular bonds within the nucleus pulposus tissue.

8. The method of claim 1, further comprising:

positioning the return electrode on an outer surface of the patient'"'"'s body, and conducting electric current from the at least one active electrode terminal, through the patient'"'"'s body, to the return electrode.

9. The method of claim 1, wherein the at least one active electrode terminal comprises a single, active electrode terminal at the distal end of a shaft.

10. The method of claim 1, wherein the at least one active electrode terminal comprises a plurality of electrically isolated active electrode terminals at the distal end of a shaft.

11. The method of claim 1, further comprising:

during said applying step, aspirating fluid from within the nucleus pulposus.

12. The method of claim 10, further comprising:

independently controlling current flow from at least two of the plurality of active electrode terminals based on impedance between each of the plurality of active electrode terminals and the return electrode.

13. The method of claim 1, further comprising:

aspirating tissue fragments from the disc through an aspiration lumen of an instrument; and

applying high frequency voltage to an aspiration electrode coupled to the aspiration lumen, the high frequency voltage applied to the aspiration electrode being sufficient to remove at least a portion of the tissue fragments.

14. The method of claim 13, wherein the aspiration electrode comprises a screen electrode located across a distal opening of the aspiration lumen, and the screen electrode having a plurality of openings for aspiration of tissue fragments therethrough.

15. A method for ablating nucleus pulposus tissue from an intervertebral disc within a patient'"'"'s spine, the method comprising:

a) positioning at least one active electrode terminal within a nucleus pulposus of the disc; and

b) applying a high frequency voltage between the at least one active electrode terminal and a return electrode, the applied voltage being sufficient to ablate the nucleus pulposus tissue, wherein a portion of the nucleus pulposus is removed and a volume of the disc is decreased.

16. The method of claim 15, further comprising:

c) prior to said steps a) and b), providing an electrosurgical probe including a shaft having a shaft distal end, wherein said positioning step comprises positioning the shaft distal end within the nucleus pulposus, and wherein the at least one active electrode terminal and the return electrode are disposed at the shaft distal end.

17. The method of claim 16, further comprising:

f) during said applying step, deflecting the shaft distal end to produce a bore within the nucleus pulposus.

18. The method of claim 15, wherein during said applying step, the nucleus pulposus tissue is ablated via molecular dissociation of components of the nucleus pulposus tissue.

19. The method of claim 15, further comprising:

d) during said applying step, axially translating the at least one active electrode terminal within the nucleus pulposus.

20. The method of claim 19, further comprising:

e) during said applying step, rotating the at least one active electrode terminal within the nucleus pulposus.

21. The method of claim 15, wherein the at least one active electrode terminal comprises an array of active electrode terminals, and said applying step comprises applying the high frequency voltage between the return electrode and the array of active electrode terminals.

22. A method of decreasing the volume of an intervertebral disc, comprising:

a) providing an electrosurgical probe, the probe including a distal working end, at least one active electrode terminal disposed at the working end, and a return electrode disposed at the working end;

b) positioning the working end of the probe within the disc such that both the at least one active electrode terminal and the return electrode are positioned within the nucleus pulposus; and

c) while both the at least one active electrode terminal and the return electrode are positioned according to said step b), applying a high frequency voltage between the return electrode and the at least one active electrode terminal, wherein the applied voltage effects ablation of a portion of the nucleus pulposus.

23. The method of claim 22, further comprising:

d) while the at least one active electrode terminal and the return electrode are positioned within the nucleus pulposus according to said step b), and prior to said step c), limiting axial travel of the probe.

24. The method of claim 23, wherein the disc includes an annulus fibrosus external to the nucleus pulposus, wherein said step d) anchors the working end of the probe within the nucleus pulposus, and prevents movement of the working end towards the annulus fibrosus during said step c).

25. The method of claim 23, wherein said step d) allows for ablation of the nucleus pulposus while preventing ablation of the annulus fibrosus.

26. The method of claim 23, wherein the probe includes a mechanical stop, and wherein limiting the axial travel of the probe is effected via the mechanical stop.

27. The method of claim 22, wherein the disc includes an annulus fibrosus external to the nucleus pulposus, and said step b) comprises positioning both the at least one active electrode terminal and the return electrode within the nucleus pulposus at a location remote from the annulus fibrosus.

28. The method of claim 22, wherein the disc includes an annulus fibrosus external to the nucleus pulposus, and wherein the voltage applied in said step c) has substantially no effect on the annulus fibrosus.

29. The method of claim 22, wherein the probe further includes an aspiration lumen and an aspiration electrode coupled to the aspiration lumen, and the method further comprises:

e) aspirating tissue fragments from the disc towards the aspiration lumen; and

f) applying high frequency voltage to the aspiration electrode, the high frequency voltage applied to the aspiration electrode being sufficient to ablate at least a portion of the tissue fragments.

30. The method of claim 29, wherein the aspiration electrode comprises a screen electrode located across a distal opening of the aspiration lumen, the screen electrode having a plurality of openings therein, and the plurality of openings for aspiration of tissue fragments therethrough.

31. The method of claim 22, further comprising:

g) delivering an electrically conductive fluid to the working end of the probe, wherein the electrically conductive fluid provides a current flow path between the at least one active electrode terminal and the return electrode.

32. The method of claim 22, further comprising:

h) during said applying step, translating the at least one active electrode terminal within the nucleus pulposus.