Electrosurgical system for treating restenosis of body lumens

• US 7,505,812 B1
• Filed: 07/16/1999
• Issued: 03/17/2009
• Est. Priority Date: 05/10/1993
• 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.
• Primary Examiner(s): Mendez; Manuel A
• Application Number:
  US09/354,835
• Time in Patent Office: 3,532 Days
• Field of Search: 606/39, 606/41, 606/46, 606/32, 607/99, 607/105, 607/113, 604/35, 604/114, 604/22
• US Class Current: 604/20
• 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 catheter system for maintaining patency in a body passage having an intraluminal prosthesis positioned therein, the prosthesis having a cylindrical wall, wherein occlusive media has grown through or around the cylindrical wall of the prosthesis and into the body passage, the catheter system comprising:

a catheter body having a distal end portion and a proximal end portion, the distal end portion being sized to pass through the prosthesis;

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

a return electrode positioned on the distal end portion of the catheter body; and

at least one connector extending through the catheter body for electrically coupling the at least one active electrode and the return electrode to a source of high frequency electrical energy;

wherein said at least one active electrode and said return electrode are sized and positioned such that electrically conductive fluid in a pathway between said electrodes forms a plasma when selected voltage potentials are applied to said electrodes from said source of high frequency electrical energy, and wherein said occlusive media is disintegrated by said plasma wherein said at least one active electrode and said return electrode are configured such that current flow through the prosthesis is minimized and wherein the catheter system further comprises an electrically insulating support member affixed to the distal end portion of the catheter body, the at least one active electrode being secured within the support member, and the support member comprising an inorganic material and wherein the support member has a central lumen therethrough, and wherein the catheter system further comprises a guidewire disposed within the central lumen, wherein the catheter body is axially and rotationally moveable with respect to the guidewire.

2. The catheter system of claim 1, further comprising:

a source of electrically conductive fluid; and

an internal lumen within the catheter body, the internal lumen coupled to the source of electrically conductive fluid for delivering the electrically conductive fluid between the return electrode and the at least one active electrode.

3. The catheter system of claim 1, further comprising an aspiration system for aspirating products of ablation from the body passage in a region around the occlusive media.

4. The catheter system of claim 3, wherein the aspiration system comprises:

a suction lumen within the catheter body, the suction lumen having a distal opening adjacent to the at least one active electrode; and

a vacuum system coupled to the suction lumen.

5. The catheter system of claim 1, further comprising a fluid delivery system for displacing naturally occurring body fluids from the body passage in a region around the occlusive media.

6. The catheter system of claim 5, wherein the fluid delivery system comprises:

a source of electrically conductive fluid; and

an internal lumen within the catheter body, the internal lumen coupled to the electrically conductive fluid source for delivering the electrically conductive fluid to the distal end portion of the catheter body.

7. The catheter system of claim 1, wherein the at least one active electrode comprises at least six, electrically independent, active electrodes, each of the six active electrodes extending distally from said electrically insulating support member disposed at the distal end portion of the catheter body.

8. The catheter system of claim 1, further comprising a power limiting element coupled to the at least one active electrode for limiting power to the at least one active electrode based on impedance between the at least one active electrode and the return electrode.

9. The catheter system of claim 1, wherein the at least one active electrode and the return electrode jointly define a tissue ablation region of the catheter system, wherein the current flow path is substantially confined to the tissue ablation region, thereby preventing electric current flow to the prosthesis, and preventing injury to the body passage.

10. The catheter system of claim 1, wherein the at least one active electrode is a plurality of active electrodes that are substantially cylindrical.

11. The catheter system of claim 10, wherein each of the plurality of active electrodes comprises a material selected from the group consisting of:

platinum, stainless steel, titanium, tantalum, tungsten, and their alloys.

12. The catheter system of claim 10, wherein the plurality of active electrodes comprise six active electrodes.

13. The catheter system of claim 12, wherein the six active electrodes are distributed in a circular arrangement within said support member.

14. The catheter system of claim 10, wherein the plurality of active electrodes are electrically independent from each other.

15. The catheter system of claim 1, further comprising said high frequency electrical energy source.

16. The catheter of claim 1, wherein the return electrode is associated with a guidewire that is axially movable relative to said active electrode.

17. The catheter of claim 1, wherein the prosthesis is a stent adapted to maintain the patency of blood vessels.

18. The catheter of claim 16, further comprising an inflatable member positioned distal to said active electrode, said inflatable member being inflatable to occlude the lumen downstream of the active electrode such that fragments of tissue are prevented from moving distal of said inflatable member.

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

a catheter body having a distal end portion and a proximal end portion, the distal end portion being sized to pass through the prosthesis, said catheter body comprising a guidewire lumen;

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

a return electrode positioned on the distal end portion of the catheter body; and

at least one connector extending through the catheter body for electrically coupling the at least one active electrode and the return electrode to a source of high frequency electrical energy;

wherein said at least one active electrode and said return electrode are adapted such that electrically conductive fluid in a pathway between said electrodes forms a plasma when selected voltage potentials are applied to said electrodes from said source of high frequency electrical energy, and wherein said occlusive media is disintegrated by said plasma and wherein the catheter system further comprises a guidewire disposed within the guidewire lumen, wherein the catheter body is axially and rotationally moveable with respect to the guidewire.

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

a catheter body having a distal end portion and a proximal end portion, the distal end portion being sized to pass through the prosthesis, said catheter body comprising a guidewire lumen;

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

a return electrode positioned on the distal end portion of the catheter body;

at least one connector extending through the catheter body for electrically coupling the at least one active electrode and the return electrode to a source of high frequency electrical energy wherein said at least one active electrode and said return electrode are adapted such that electrically conductive fluid in a pathway between said electrodes forms an electrically conductive pathway when a voltage potential is applied between said electrodes from said source of high frequency electrical energy such that said occlusive media is removed; and

a guidewire disposed within the guidewire lumen such that said catheter is axially and rotationally moveable with respect to the guidewire.