Systems and methods for electrosurgery

• US 7,270,658 B2
• Filed: 03/10/2003
• Issued: 09/18/2007
• Est. Priority Date: 05/12/2000
• Status: Expired due to Fees

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Woloszko, Jean, Eggers, Philip E., Hovda, David C., Thapliyal, Hira V.
• Primary Examiner(s): Cohen; Lee S.
• Application Number:
  US10/384,050
• Publication Number:
  US 20030212395A1
• Time in Patent Office: 1,653 Days
• Field of Search: 607/99, 606/41
• US Class Current: 606/32
• 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 2017/00261 Discectomy
• 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 2018/00291 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 2018/00577 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 2018/00702 : Power or energy
• CPC Class Codes: A61B 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00827 : Current
• 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 2018/1273 : 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 90/11 : with guides for needles or instruments, e.g. arcuate slides or ball joints

Abstract

Methods and apparatus for selectively applying electrical energy to a target location within a patient'"'"'s body, particularly including tissue in the spine. In a method of the invention high frequency (RF) electrical energy is applied to one or more active electrodes on an electrosurgical probe in the presence of an electrically conductive fluid to remove, contract or otherwise modify the structure of tissue targeted for treatment. In one aspect, a dura mater and spinal cord are insulated from the electrical energy by an insulator positioned on a non-active side of the probe. In another aspect, a plasma is aggressively formed in the electrically conductive fluid by delivering a conductive fluid to a distal end portion of the probe and aspirating the fluid from a location proximal of the return electrode. In another aspect, a distal end of an electrosurgical probe having at least one electrode on a biased, curved, bent, or steerable shaft is guided or steered to a target site within an intervertebral disc having a disc defect for treatment of tissue to be treated at the target site by the selective application of electrical energy thereto.

Claims

1. A method of treating an intervertebral disc having a nucleus pulposus and an annulus fibrosus, the method comprising:

advancing a distal end of an electrosurgical instrument into the annulus fibrosus, wherein ar active electrode and a return electrode are positioned on the distal end of the electrosurgical instrument;

moving the distal end of the electrosurgical instrument to a curved configuration that approximates a curvature of an inner surface of the annulus fibrosus; and

delivering a high frequency voltage between the active electrode and the return electrode to treat the inner surface of the annulus fibrosus with a plasma in the vicinity of said active electrode, and wherein said active electrode having a shape and size different than said return electrode so as to create a higher current density at said active electrode than at said return electrode.

2. The method of claim 1, wherein advancing comprises channeling through the annulus fibrosus by delivering a high frequency voltage between the active electrode and the return electrode.

3. The method of claim 1 wherein moving comprises biasing the distal end.

4. The method of claim 1 wherein moving comprises steering the distal end.

5. The method of claim 4 wherein steering comprises actuating an actuator positioned at the proximal portion of the electrosurgical instrument.

6. The method of claim 1 further comprising tracking the movement or location of the distal end of the electrosurgical instrument.

7. The method of claim 6 wherein tracking comprises visualizing the distal end fluoroscopically.

8. The method of claim 1 wherein advancing comprises positioning the active electrode and return electrode within the nucleus pulposus.

9. The method of claim 1 wherein at least some tissue in contact with said plasma is ablated.

10. The method of claim 9 wherein said tissue ablated comprises at least a portion of annulus fibrosis.

11. The method of claim 9 wherein said tissue ablated comprises at least a portion of nucleus pulposus.

12. The method of claim 1 further comprising providing an electrically conductive fluid from outside the body in the vicinity of said distal end to facilitate the format on of said plasma.

13. A method of treating an intervertebral disc, the method comprising:

positioning a distal end of an electrosurgical probe within close proximity of an outer surface of the intervertebral disc, the distal end of the electrosurgical probe comprising at least one active electrode;

delivering a high frequency voltage between the at least one active electrode and a return electrode, the high frequency voltage being sufficient to create a channel in the disc tissue;

advancing the active electrode through the channel created in the intervertebral disc;

conforming the distal end of the electrosurgical probe to a curved configuration that approximates a curvature of an inner surface of an annulus fibrosus; and

delivering a high frequency voltage between the active electrode and the return electrode to treat the inner surface of the annulus fibrosus.

14. The method of claim 13 further comprising delivering a heating voltage between a coagulation electrode and the return electrode to heat at least a portion of the intervertebral disc, wherein the heating voltage is sufficient to coagulate a severed blood vessel, and the heating voltage is insufficient to induce molecular dissociation of disc tissue components ablate the intervertebral disc tissue.

15. The method of claim 13 wherein conforming comprises biasing the distal end or steering the distal end.

16. An apparatus for treating intervertebral discs, the apparatus comprising:

a steerable shaft defining a shaft distal end portion, wherein the shaft distal end portion is moveable to a curved configuration that approximates the curvature of the inner surface of an annulus fibrosus;

at least one active electrode positioned on the distal end portion of the shaft;

a return electrode positioned proximal of the at least one active electrode;

a high frequency energy source configured to create a voltage difference between the active electrode and the return electrode; and

a coagulation electrode associated with the distal end portion and electrically coupled to said high frequency energy source.

17. The apparatus of claim 16 further comprising a fluid delivery lumen configured to deliver a conductive fluid to the at least one active electrode.

18. The apparatus of claim 17 further comprising an aspiration lumen adapted to aspirate the conductive fluid to a location adjacent the active electrode.

19. The apparatus of claim 16, wherein the high frequency energy voltage source is configured to deliver a high frequency voltage to the coagulation electrode, wherein the high frequency voltage is insufficient for the coagulation electrode to produce an effect selected from the group consisting of:

generating a plasma in the presence of an electrically conductive fluid, ablating tissue in a temperature range of 45°

to 90°

C., and causing molecular dissociation of tissue components.