System for inducing desirable temperature effects on body tissue

• US 20120158101A1
• Filed: 02/24/2012
• Published: 06/21/2012
• Est. Priority Date: 10/18/2006
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Vessix Vascular, Inc. (Boston Scientific Corporation)
• Inventors: Stone, Corbett W., Hoey, Michael F., Blanck, Arthur G., Briggs, Len, Perry, Mike, Gustus, Rolfe Tyson
• Granted Patent: US 10,413,356 B2
• Time in Patent Office: Days
• US Class Current: 607/101
• 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 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/0022 Balloons
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61F 2007/126 for invasive application, e.g. for introducing into blood vessels
• CPC Class Codes: A61F 7/12 Devices for heating or cooling internal body cavities
• CPC Class Codes: A61F 7/123 using a flexible balloon containing the thermal element

Abstract

A catheter and catheter system may be used to treat disease tissue by gentle heating in combination with gentle or standard dilation. An elongate flexible catheter body with a radially expandable balloon having a plurality of electrodes engage tissue including diseased tissue when the structure expands.

Claims

1. A system for inducing desirable temperature effects on a body tissue disposed about a blood vessel, the system comprising:

a catheter body having a proximal end and a distal end with an axis therebetween;

a radially expandable member supported by the distal end of the catheter body,

the expandable member having a low profile insertion configuration and a larger profile

configuration; and

a plurality of electrodes disposed about the expandable member so as to radially couple with a wall of the blood vessel and define a plurality of remodeling zones in the tissue when the expandable member is in the large profile configuration within the blood vessel, the electrodes configured to transmit a tissue remodeling energy between the electrodes and the tissue while inhibiting damage to the blood vessel.

2. The system of claim 1, wherein the radially expandable member comprises a balloon, wherein the electrodes are mounted on a surface of the balloon arranged in an array.

3. The system of claim 2, wherein the electrodes are circumferentially and axially offset.

4. The system of claim 2, wherein the plurality of electrodes are included in a plurality of separate flexible circuits distributed on the balloon.

5. The system of claim 4, wherein each of the flexible circuits includes an associated bipolar electrode pair.

6. The system of claim 5, wherein the electrodes of each bipolar electrode pair are disposed on a substrate of the associated flexible circuit so as to have a predetermined bipolar pair separation distance therebetween when the balloon is in the large profile configuration.

7. The system of claim 6, wherein each electrode comprises a plurality of pads, the pads electrically coupled together by a conductive trace, an insulation layer being disposed over the trace, and an electrode surface of the pads extending from the insulation layer so as to allow flexing along a length of the electrode.

8. The system of claim 3 wherein the electrodes comprise a plurality of bipolar electrode pairs configured to be energized with RF energy, wherein the electrodes of the electrode pairs are circumferentially separated.

9. The system of claim 8, wherein a circumferential distance between the electrodes of the electrode pairs is within a range from about 0.25 to 2.5 mm.

10. The system of claim 8, wherein a spacing between the electrodes of the bipolar electrode pairs is such that the remodeling zones between electrodes of each pair, in combination, substantially circumscribe the circumference of the balloon.

11. The system of claim 8, wherein the electrodes are configured so that the remodeling energy is applied at a frequency at which the body tissue is more conductive than collateral tissues.

12. The system of claim 1 further comprising:

a controller electrically coupling a power source to the plurality of electrodes for heating the remodeling zones with the energized electrodes so that a temperature of the tissue ranges from about 50°

C. to about 90°

C.

13. The system of claim 12, wherein the power source comprises an RF generator and the controller is configured to selectively direct RF energy to electrode pairs of the plurality of electrodes.

14. The system of claim 12, wherein the controller is configured to use temperature information of the tissue as feedback for delivering controlled treatment energy to the electrodes.

15. The system of claim 12, wherein the controller is configured to energize the electrode pairs according to a duty cycle.

16. The system of claim 12, wherein the controller is configured to energize the electrode pairs with about 0.25 to 20 Watts average power for a duration between 1 to 180 seconds.

17. The system of claim 12, wherein the controller is configured to energize the electrode pairs so as to deliver 8 to 45 Joules of energy in a treatment.

18. The system of claim 4 wherein an electrode length of each electrode is between 8 mm and 16 mm.

19. The system of claim 1, wherein the system is configured to effect controlled delivery of remodeling energy using a characteristic of the tissue measured with one or more electrode pairs.

20. The system of claim 19, wherein the characteristic comprises a load impedance.

21. A system for inducing desirable temperature effects on a body tissue disposed about a blood vessel, the system comprising:

an intravascular catheter body having a proximal end and a distal end with an axis therebetween;

an intravascular balloon supported by the distal end of the catheter body, the balloon having a low profile insertion configuration and a larger profile configuration; and

a plurality of flex circuits distributed about the balloon, each flex circuit including a pair of electrodes having a predetermined bipolar pair separation distance therebetween;

a power source configured to electrically couple with the electrodes of the flex circuits, and to transmit a tissue remodeling energy between the electrodes of the pairs on the flex circuits so as to provide an associated remodeling zone in the tissue for each pair of electrodes when the balloon is inflated to the large profile configuration within the blood vessel.

22. A method for inducing desirable temperature effects on a desired body tissue disposed about a body lumen of a patient, the method comprising:

positioning a radially expandable member supported by a distal end of a catheter body within the lumen adjacent the desired tissue to be heated, the expandable member having a low profile insertion configuration and a larger profile configuration;

expanding the expandable member to the larger profile configuration within the lumen so as to engage a plurality of electrodes against a wall of the lumen, the plurality of electrodes defining a plurality of remodeling zones in the tissue;

energizing the plurality of electrodes with a controller having a power source electrically coupled to the plurality of electrodes; and

heating the remodeling zones in the tissue with the energized electrodes so as to induce desirable temperature effects on the body tissue while inhibiting damage to the wall of the lumen.

23. The method of claim 22, wherein the expandable member comprises a balloon having the plurality of electrodes mounted on an outer surface thereof, and wherein expanding the expandable member comprises inflating the balloon.

24. The method of claim 22, wherein the body lumen comprises a blood vessel, and the plurality of electrodes comprise a plurality of bipolar electrode pairs such that expanding the expandable member urges one or more of the plurality of bipolar electrode pairs against the vessel wall, and

energizing the plurality of electrodes comprises delivering energy to the one or more bipolar electrode when engaged against the vessel with an RF power source.

25. The method of claim 22, wherein the body lumen is an artery, and wherein heating with the energized electrodes is controlled so as to limit heating of an adventitial layer to below a deleterious response threshold.

26. The method of claim 25, wherein heating is controlled by selectively firing bipolar electrode pairs of the plurality.

27. The method of claim 26, wherein the bipolar electrode pairs are selectively fired according to a duty cycle.

28. The method of claim 22, wherein the remodeling zones are circumferentially and axially offset.