System and methods for electrosurgical restenosis of body lumens

• US 6,179,824 B1
• Filed: 06/13/1997
• Issued: 01/30/2001
• Est. Priority Date: 05/10/1993
• 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.
• Primary Examiner(s): Thompson, Mike
• Assistant Examiner(s): Kennedy, Sharon
• Application Number:
  US08/874,173
• Time in Patent Office: 1,327 Days
• Field of Search: 604/114, 604/22, 604/500, 604/28
• US Class Current: 604/500
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• 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 18/1233 with circuits for assuring patient safety
• 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 2017/00106 ultrasonic
• 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 2018/00214 : Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00327 : Ear, nose or throat
• CPC Class Codes: A61B 2018/00392 : Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/0041 : Removal of thrombosis
• CPC Class Codes: A61B 2018/00422 : Angioplasty
• CPC Class Codes: A61B 2018/0047 : Upper parts of the skin, e.g. skin peeling or treatment of wrinkles
• CPC Class Codes: A61B 2018/00476 : Hair follicles
• 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 2018/00601 : Cutting
• 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 2018/00738 : Depth, e.g. depth of ablation
• CPC Class Codes: A61B 2018/00755 : Resistance or impedance
• 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 2018/00982 : 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 2018/1246 : characterised by the output polarity
• 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 2018/1407 : Loop
• 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 2090/378 : using ultrasound
• CPC Class Codes: A61B 2090/3782 : transmitter or receiver in catheter or minimal invasive instrument
• 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: A61F 2/95 : Instruments specially adapted for placement or removal of stents or stent-grafts
• 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
• CPC Class Codes: A61N 1/06 : for high-frequency therapy

Abstract

The present invention comprises apparatus and methods for maintaining patency in body passages subject to occlusion by invasive tissue growth. The apparatus and methods of the present invention may be used to open and maintain patency in virtually any hollow body passage which may be subject to occlusion by invasive cellular growth or invasive solid tumor growth. Suitable hollow body passages include ducts, orifices, lumens, and the like, with exemplary body passages including the coronary arteries. The present invention is particularly useful for reducing or eliminating the effects of restenosis in coronary arteries by selectively removing tissue ingrowth in or around stents anchored therein.

Claims

1. A method for maintaining patency in a body passage having an intraluminal prosthesis with a cylindrical wall positioned therein, wherein occlusive media has grown through or around the cylindrical wall of the prosthesis into the body passage, the method comprising:

positioning an active electrode near or at the occlusive media;

delivering electrically conductive fluid to the prosthesis such that the active electrode is substantially surrounded by the electrically conductive fluid; and

applying high frequency voltage to the active electrode to selectively remove the occlusive media without directly applying current to the prosthesis.

2. The method of claim 1 further comprising applying high frequency voltage to the active electrode and a return electrode positioned within the body lumen and spaced from the occlusive media such that an electrical current flows from the active electrode, through the the electrically conductive fluid, and to the return electrode.

3. The method of claim 2 wherein the return electrode is positioned radially inward from the active electrode such that the electrical current flows from the active electrode radially inward to the return electrode, thereby inhibiting current flow through the prosthesis.

4. The method of claim 2 further comprising generating a current flow path through the electrically conducting fluid between the return electrode and the active electrode.

5. The method of claim 1 further comprising advancing a catheter body into the lumen to position the active electrode in close proximity with the occlusive media.

6. The method of claim 5 wherein the active electrode is positioned at a distal portion of the catheter body, the method further comprising:

reciprocally rotating at least the distal portion of the catheter body during the applying step; and

advancing the catheter body through the vacancy left by the ablated occlusive media.

7. The method of claim 1 further comprising applying high frequency voltage to an electrode array of electrically isolated active electrodes and a return electrode such that an electrical current flows from each of the active electrodes, through the electrically conductive fluid, and to the return electrode through the current flow path.

8. The method of claim 7 further comprising independently controlling current flow from at least two of the active electrodes based on impedance between the active electrodes and the return electrode.

9. The method of claim 1 further comprising:

before the applying step, fluidly isolating a region around the occlusive media within the body passage to confine products of ablation within said region; and

aspirating said ablation products from the body passage.

10. The method of claim 9 wherein the fluidly isolating step comprises:

advancing a first balloon to a portion of the body passage proximal to said region;

inflating said first balloon to inhibit fluid flow therethrough;

positioning a second balloon at a portion of the body passage distal to said region; and

inflating said second balloon to inhibit fluid flow therethrough.

11. The method of claim 1 further comprising:

before the applying step, delivering electrically conductive fluid to a region around the occlusive media to displace naturally occurring bodily fluid from said region; and

fluidly isolating said region to confine the electrically conducting fluid within said region.

12. The method of claim 11 further comprising:

during the applying step, supplying electrically conductive fluid to said region; and

entraining gaseous products of ablation within the electrically conductive fluid and aspirating the gaseous ablation products from said region.

13. The method of claim 1 farther comprising advancing a catheter body into the lumen to position the active electrode in close proximity with the tissue ingrowth.

14. The method of claim 1 further comprising confining the electrical current flow to a central portion of the body passage.

16. The method of claim 13 further comprising applying sufficient high frequency voltage to the active electrode and the return electrode to generate high electric field intensities around the active electrode, wherein the electric field intensities are sufficient to cause molecular disintegration of tissue structure.

17. The method of claim 13 wherein the high frequency voltage is sufficient to vaporize the fluid in a thin layer over at least a portion of the active electrode and induce the discharge of energy from the vapor layer.

18. The method of claim 17 wherein at least a portion of the energy induced from the vapor layer is in the form of photons having a wavelength in the ultraviolet spectrum or energetic electrons.

19. The method of claim 13 further comprising applying high frequency voltage to an electrode array of electrically isolated active electrodes and a return electrode such that an electrical current flows from each of the active electrodes, through the region of the tissue ingrowth, and to the return electrode through the current flow path.

20. The method of claim 19 wherein the electrode array comprises between 4 to 50 active electrodes.

21. The method of claim 13 wherein the high frequency voltage is at least 300 volts peak to peak.

22. The method of claim 13 wherein the high frequency voltage is in the range from 600 to 1400 volts peak to peak.

23. The method of claim 13 further comprising directing an electrically conducting fluid along a fluid path past the return electrode and to the active electrode to generate the current flow path between the active electrode and the return electrode.

24. The method of claim 13 further comprising submerging the active electrode and the return electrode within naturally occurring electrically conducting fluid within the body lumen.

25. The method of claim 13 wherein the electrically conducting fluid comprises isotonic saline.

15. A method for recanalizing a body lumen having an intraluminal prosthesis disposed therein, the body lumen having tissue ingrowth in or around the prosthesis, the method comprising:

positioning an active electrode into at least close proximity with the tissue ingrowth in the presence of an electrically conducting fluid;

positioning a return electrode within the electrically conducting fluid to generate a current flow path between the tissue ingrowth and the return electrode; and

applying high frequency voltage to the active electrode and the return electrode such that an electrical current flows from the active electrode, through the region of the tissue ingrowth, and to the return electrode through the current flow path.