Method for electrosurgical treatment of intervertebral discs

• US 20010029370A1
• Filed: 01/19/2001
• Published: 10/11/2001
• Est. Priority Date: 06/07/1995
• Status: Active Grant

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Hodva, David C., Eggers, Philip E., Ellsberry, Maria B., Thapliyal, Hira V.
• Granted Patent: US 6,464,695 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1477 Needle-like probes
• 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 2017/00101 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 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/00274 Prostate operation, e.g. prostatectomy, turp, bhp treatment
• 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 2018/00291 : using suction
• 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 2018/0044 : Spinal cord
• CPC Class Codes: A61B 2018/00505 : Urinary tract
• CPC Class Codes: A61B 2018/00547 : Prostate
• 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 2018/00589 : Coagulation
• CPC Class Codes: A61B 2018/00607 : Coagulation and cutting with the same instrument
• 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 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00827 : Current
• CPC Class Codes: A61B 2018/00875 : Resistance or impedance
• CPC Class Codes: A61B 2018/00982 : combined with or comprising means for visual or photographic inspections inside the body, e.g. endoscopes
• 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 2018/1425 : Needle
• 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 2018/162 : located on the probe body
• CPC Class Codes: A61B 2018/165 : Multiple indifferent electrodes
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 2218/007 : Aspiration
• CPC Class Codes: A61B 90/11 : with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61F 2/2493 : Transmyocardial revascularisation [TMR] devices

Abstract

Systems, apparatus and methods for ablation, resection, aspiration, collagen shrinkage and/or hemostasis of tissue and other body structures in open and endoscopic spine surgery. In particular, the present invention includes a channeling technique in which small holes or channels are formed within spinal discs, and thermal energy is applied to the tissue surface immediately surrounding these holes or channels to cause thermal damage to the tissue surface, thereby stiffening the surrounding tissue structure and for reducing the volume of the disc to relieve pressure on the surrounding nerves. High frequency voltage is applied between one or more active electrode(s) and one or more return electrode(s) to volumetrically remove or ablate at least a portion of the disc tissue, and the active electrode(s) are advanced through the space left by the ablated tissue to form a channel, hole, divot or other space in the disc tissue. In addition, the high frequency voltage effects a controlled depth of thermal heating of the tissue surrounding the hole to thermally damage or create a lesion within the tissue surrounding the hole to debulk and/or stiffen the disc structure, thereby relieving neck or back pain.

Claims

1. A method for treating intervertebral discs:

positioning an active electrode adjacent to a disc;

applying high frequency voltage between the active electrode and a return electrode, the high frequency voltage being sufficient to ablate the disc tissue;

during the applying step, advancing the active electrode into the disc tissue to generate a space within the tissue; and

removing the active electrode from the space within the tissue.

2. The method of

claim 1

further comprising, during the removing step, applying high frequency voltage between the active and return electrodes, the high frequency voltage being sufficient to coagulate blood at the tissue surface surrounding the space.

3. The method of

claim 1

further comprising providing an electrically conductive fluid around the active electrode and between the active and return electrodes prior to the applying step.

4. The method of

claim 3

wherein the providing step comprises positioning the active and return electrodes within a supply of electrically conductive fluid and then positioning the active and return electrodes adjacent to the spinal disc.

5. The method of

claim 3

wherein the providing step comprises delivering the electrically conductive fluid to the active and return electrodes at the target site.

6. The method of

claim 3

wherein the electrically conductive fluid is selected from the group comprising a gel, a liquid and a gas.

7. The method of

claim 1

further comprising applying a sufficient high frequency voltage difference between the active and return electrodes to effect molecular dissociation of at least a portion of the disc tissue during the advancing step.

8. The method of

claim 1

wherein the applying step includes generating a voltage gradient between the active and return electrodes, the voltage gradient being sufficient to create an electric field that breaks down the tissue through molecular dissociation.

9. The method of

claim 3

further comprising generating a current flow path between the active and return electrodes with the electrically conductive fluid.

10. The method of

claim 1

wherein the active electrode comprises a single, active electrode at the distal end of a shaft.

11. The method of

claim 1

wherein the active electrode comprises a plurality of electrically isolated electrode terminals at the distal end of a shaft.

12. The method of

claim 3

further comprising aspirating fluid from the target site.

13. The method of

claim 1

further comprising applying sufficient voltage to the active electrode in the presence of electrically conducting fluid to vaporize at least a portion of the fluid between the active electrode and the tissue structure at the target site.

14. The method of

claim 13

further comprising accelerating charged particles from the vaporized fluid to the tissue to cause dissociation of the molecular bonds within the tissue structures.

15. The method of

claim 2

wherein the high frequency voltage during the removal step is sufficient to thermally damage the surface of the disc tissue surrounding the space.

16. The method of

claim 1

further comprising axially translating the active electrode to form a hole through at least a portion of the disc tissue.

17. The method of

claim 1

further comprising transversely translating the active electrode relative to the disc tissue to form a channel along a surface of the disc.

18. The method of

claim 1

wherein the space has a maximum lateral dimension less than about 2 mm.

19. The method of

claim 1

wherein the space has a maximum lateral dimension less than about 1 mm.

20. The method of

claim 1

wherein the active and return electrodes are both located on a shaft of an electrosurgical instrument.

21. The method of

claim 20

further comprising introducing at least the distal end portion of the shaft through a percutaneous penetration in the patient to the disc.

22. The method of

claim 3

wherein the electrically conductive fluid is not present during the removal step.

23. The method of

claim 20

wherein the return electrode is axially spaced at least about 1.0 mm from the active electrode.

24. The method of

claim 20

further comprising, during the removal step, deactivating the active electrode and applying a high frequency voltage difference between a second active electrode and one or more return electrodes on the instrument shaft.

25. The method of

claim 24

wherein the second active electrode is spaced proximally from the return electrode.

26. The method of

claim 25

wherein the instrument shaft comprises a second return electrode spaced proximally from the second active electrode, the method comprising, during the removal step, applying a high frequency voltage difference between the second active electrode and the first and second return electrodes.

27. The method of

claim 20

further comprising, during the removal step, deactivating the active electrode and applying a high frequency voltage difference between the return electrode on the instrument shaft and a dispersive return electrode coupled to an external surface of the patient.

28. A method for treating intervertebral discs comprising:

positioning an active electrode adjacent to, or within, a patient'"'"'s spinal disc; and

applying high frequency voltage between the active electrode and a return electrode, the high frequency voltage being sufficient to modify a tissue structure within the spinal disc such that a volume of the spinal disc is reduced.

29. The method of

claim 28

wherein the applying step comprises applying sufficient voltage between the active and return electrodes to thermally damage the tissue structure.

30. The method of

claim 28

further comprising, prior to the applying step, ablating a portion of the tissue structure to form a space within the tissue structure, and then applying sufficient high frequency voltage to modify the surface immediately surrounding the space.

31. The method of

claim 28

further comprising reducing a sufficient volume of the spinal disc to decompress a nerve in or around the spinal disc.

32. A method for treating a degenerative intervertebral disc comprising:

positioning one or more active electrode(s) adjacent to selected nerves embedded in the walls of an intervertebral disc;

positioning one or more return electrode(s) in the vicinity of the active electrode(s) in or around the intervertebral disc; and

applying a sufficient high frequency voltage difference between the active and return electrodes to denervate the selected nerves.

33. A method for treating degenerative intervertebral discs comprising:

positioning one or more active electrode(s) adjacent to or within the nucleus pulposis of an intervertebral;

positioning one or more return electrode(s) in the vicinity of the active electrode(s) in or around the intervertebral disc; and

applying a sufficient high frequency voltage difference between the active and return electrodes to reduce water content of the nucleus pulposis and shrink the collagen fibers within the nucleus pulposis to tighten the disc.

34. A method for treating degenerative intervertebral discs comprising:

positioning one or more active electrode(s) adjacent to an annular fissure on the inner wall of the annulus fibrosis of an intervertebral disc;

positioning one or more return electrode(s) in the vicinity of the active electrode(s) in or around the intervertebral disc; and

applying a sufficient high frequency voltage difference between the active and return electrodes to shrink the collagen fibers in the annular fissure.

35. A system for treating intervertebral discs comprising:

an electrosurgical instrument having a shaft with a proximal end portion and a distal end portion;

an electrode assembly comprising at least one active electrode positioned on the distal portion of the shaft, and at least one return electrode positioned on the shaft and axially spaced from the active electrode;

a coagulation electrode; and

a high frequency power supply coupled to the active, return and third electrodes, the power supply being capable of applying a first high frequency voltage difference between the active and return electrodes sufficient to ablate tissue, and a second high frequency voltage difference between the return electrode and the third electrode sufficient to coagulate blood and insufficient to ablate tissue.

36. The system of

claim 35

wherein the coagulation electrode is positioned on the shaft and axially spaced from the return electrode.

37. The system of

claim 35

wherein the distal end portion of the shaft is sized for delivery through a percutaneous opening in the patient to a spinal disc.

38. The system of

claim 35

further comprising a voltage reduction element coupled between the power source and the coagulation electrode to reduce the voltage applied to the coagulation electrode.

39. The system of

claim 35

wherein the coagulation electrode comprises a dispersive return electrode configured for attachment to an external skin surface of the patient.

40. The system of

claim 35

wherein the power applies the first and second high frequency voltage differences at the same time

41. The system of

claim 35

wherein the coagulation electrode is located on the instrument shaft and spaced axially from the active and return electrodes.

42. The system of

claim 35

further comprising a switch for moving between an ablation mode, wherein the third electrode is deactivated and the power supply applies a high frequency voltage difference between the active and return electrodes sufficient to ablate tissue, and a thermal mode, wherein the active electrode is deactivated and the power supply applies a high frequency voltage difference between the return electrode and the third electrode sufficient to coagulate blood and insufficient to ablate tissue.

43. The system of

claim 35

wherein the second high frequency voltage difference is in the range of about 20 to 90 volts rms and the first high frequency voltage difference is in the range of about 150 to 350 volts rms.

44. The system of

claim 35

wherein the coagulation electrode comprises an annular band spaced proximally from the return electrode and having a substantially smooth, exposed surface to reduce current densities on said surface.

45. The system of

claim 35

wherein the exposed surface of the coagulation electrode has a larger surface area than the exposed surface of the return electrode.