COAXIAL CATHETER INSTRUMENTS FOR ABLATION WITH RADIANT ENERGY

• US 20090221997A1
• Filed: 04/16/2009
• Published: 09/03/2009
• Est. Priority Date: 09/09/1994
• Status: Active Grant

• Current Assignee: Cardiofocus Incorporated
• Original Assignee: Cardiofocus Incorporated
• Inventors: Farr, Norman E., Baxter, Lincoln S., Arnold, Jeffrey M., Sinofsky, Edward L.
• Granted Patent: US 8,366,705 B2
• Time in Patent Office: Days
• US Class Current: 606/15
• CPC Class Codes: A61B 18/24 with a catheter A61B18/26, A61B18/28 take precedence
• CPC Class Codes: A61B 18/245 for removing obstructions in blood vessels or calculi
• CPC Class Codes: A61B 2017/00057 Light
• CPC Class Codes: A61B 2017/00061 spectrum
• CPC Class Codes: A61B 2018/0097 Cleaning probe surfaces
• CPC Class Codes: A61B 2018/2261 with scattering, diffusion or dispersion of light
• CPC Class Codes: A61B 2018/2266 with a lens, e.g. ball tipped
• CPC Class Codes: A61B 2018/2272 with reflective or refractive surfaces for deflecting the beam A61B2018/2261, A61B2018/2266 take precedence
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61L 2/10 Ultraviolet radiation
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: C08L 27/12 containing fluorine atoms

Abstract

A cardiac ablation instrument capable of removing blood from a treatment area is provided. The instrument includes a catheter configured to deliver a distal end thereof to a patient'"'"'s heart. The instrument can also include an expandable element coupled to the distal end of the catheter wherein the expandable member is configured to be positioned adjacent a target area thereby defining a treatment area between the expandable member and the target area. Further, the instrument can include an irrigation mechanism configured to dispense an irrigation fluid from the catheter thereby displacing blood from the treatment area. Additionally, the instrument includes an energy emitter configured to deliver energy to tissue within the treatment area. The instrument can also include a contact sensor configured to determine the presence of such blood within the treatment area. Methods for ablating tissue are also provided.

Claims

1. A cardiac ablation instrument, comprising:

an elongate catheter configured to deliver a distal end of the catheter to a position within a patient'"'"'s heart;

an expandable element coupled to the distal end of the catheter, the expandable member configured to be positioned adjacent a target area thereby defining a treatment area between the expandable member and the target area;

an irrigation mechanism configured to dispense an irrigation fluid from the elongate catheter to the treatment area thereby displacing an amount of blood from the treatment area; and

an energy emitter configured to deliver ablative energy to a tissue located within the treatment area.

2. The instrument of claim 1, wherein the irrigation fluid is a non-toxic aqueous fluid.

3. The instrument of claim 1, wherein the irrigation fluid comprises saline.

4. The instrument of claim 1, wherein the irrigation fluid comprises water.

5. The instrument of claim 1, wherein the irrigation fluid is substantially transparent.

6. The instrument of claim 1, wherein the irrigation fluid further comprises an adjuvant.

7. The instrument of claim 6, wherein the adjuvant is selected from the group consisting of a photosensitizing agent, a pharmacological agent, and an analgestic.

8. The instrument of claim 1, wherein the expandable member is configured to be positioned adjacent to an ostium of a pulmonary vein.

9. The instrument of claim 1, wherein the irrigation mechanism includes at least one port configured to dispense the irrigation fluid.

10. The instrument of claim 1, wherein the expandable member is a balloon.

11. The instrument of claim 1, wherein the energy emitter is a contact electrode.

12. The instrument of claim 11, wherein the contact electrode is coupled to the expandable member.

13. The instrument of claim 1, wherein the energy emitter is slidably disposed within an inner lumen of the catheter.

14. The instrument of claim 13, wherein the energy emitter is a radiant energy emitter, the energy emitter being configured such that an amount or a pattern of energy delivered to the tissue is dependent upon a linear position of the energy emitter relative to the inner lumen of the catheter.

15. The instrument of claim 1, wherein a distal portion of the expandable member is configured to contact the tissue area.

16. A cardiac ablation instrument, comprising:

an elongate catheter configured to deliver a distal end thereof to a position within a patient'"'"'s heart;

an irrigation mechanism configured to remove blood from a treatment area located between the distal end of the catheter and a target tissue; and

an energy emitter configured to ablate a desired cardiac tissue of the treatment area.

17. The instrument of claim 16, wherein the instrument further includes an expandable member coupled to the distal end of the catheter, a distal portion of the expandable member being configured to be positioned adjacent the target tissue.

18. The instrument of claim 16, wherein the irrigation mechanism is configured to dispense an irrigation fluid to the treatment area thereby substantially removing blood from the treatment area.

19. The instrument of claim 18, wherein the irrigation fluid is a non-toxic aqueous fluid.

20. The instrument of claim 18, wherein the irrigation fluid comprises saline.

21. The instrument of claim 16, wherein the irrigation fluid comprises water.

22. The instrument of claim 16, wherein the irrigation fluid is substantially transparent.

23. The instrument of claim 16, wherein the irrigation fluid further comprises an adjuvant.

24. The instrument of claim 23, wherein the adjuvant is selected from the group consisting of a photosensitizing agent, a pharmacological agent, and an analgestic.

25. A cardiac ablation assembly, comprising:

a catheter configured so as to deliver a distal end thereof to a position within a patient'"'"'s heart;

an expandable element coupled to a distal portion of the catheter, a distal portion of the expandable element being further configured to be positioned adjacent a target area thereby defining a treatment area between the expandable element and the target area;

a contact sensor configured to deliver light to a tissue within the treatment area, and further configured to detect light being reflected by the tissue; and

an energy emitter configured to ablate a tissue within the treatment area.

26. The assembly of claim 25, wherein the contact sensor is configured to deliver at least red light and green light to the tissue, and further configured to detect the reflected red light and the reflected green light.

27. The assembly of claim 26, wherein the contact sensor is configured to determine a ratio of an amount of reflected red light to an amount of reflected green light, the ratio being indicative of the presence of blood within the treatment area.

28. The assembly of claim 25, wherein the contact sensor includes at least one illumination fiber configured to deliver the light to the tissue.

29. The assembly of claim 28, wherein the contact sensor includes four illumination fibers.

30. The assembly of claim 25, wherein the reflected light is transmitted back through a collector.

31. The assembly of claim 30, wherein the collector is in communication with a spectrophotometer.

32. A method of ablating cardiac tissue, comprising:

delivering a distal end of an ablation catheter to a target area within a patient'"'"'s heart;

expanding an expandable member coupled to the distal end of the ablation catheter, a distal end of the expandable member configured to be positioned adjacent the target area thereby defining a treatment area between the expandable member and the target area;

dispensing an irrigation fluid into the treatment area thereby displacing blood from the treatment area; and

ablating a tissue of the treatment area.

33. The method of claim 32, wherein the irrigation fluid is a non-toxic aqueous fluid.

34. The method of claim 32, wherein the irrigation fluid comprises saline.

35. The method of claim 32, wherein the irrigation fluid comprises water.

36. The method of claim 32, wherein the irrigation fluid is substantially transparent.

37. The method of claim 32, wherein the irrigation fluid further comprises an adjuvant.

38. The method of claim 37, wherein the adjuvant is selected from the group consisting of a photosensitizing agent, a pharmacological agent, and an analgestic.

39. The method of claim 32, wherein the target area is a substantially circular tissue area.

40. The method of claim 39, wherein the substantially circular tissue area encircles an ostium of a pulmonary vein.

41. The method of claim 32, wherein the ablating step includes contacting a contact electrode to the tissue.

42. The method of claim 41, wherein the contact electrode is coupled to the expandable member.

43. The method of claim 32, wherein the ablating step includes sliding an energy emitter to a desired axial position within an inner lumen of the catheter, and delivering a radiation ablation energy to the tissue wherein an amount and pattern of energy delivered to the tissue is dependent on the desired axial position.

44. The method of claim 32, further comprising determining if an amount of blood is present within the treatment area.

45. The method of claim 44, wherein the determining step include delivering at least one component of white light to a tissue, and measuring an amount of the at least one component of the light being reflected by the tissue.

46. The method of claim 45, wherein green light is delivered to a tissue, and the amount of green light reflected by the tissue is measured.

47. The method of claim 46, further comprising delivering red light to the tissue, and detecting the amount of red light reflected by the tissue.

48. The method of claim 47, further comprising determining a ratio of red light reflected by the tissue to an amount of green light reflected by the tissue, the ratio being indicative of the presence of blood within the treatment area.