Method for ablating body tissue

• US 7,950,397 B2
• Filed: 05/11/2007
• Issued: 05/31/2011
• Est. Priority Date: 05/12/2006
• Status: Active Grant

• Current Assignee: Auris Health, Inc. (Johnson & Johnson)
• Original Assignee: VytronUS, Inc. (Johnson & Johnson)
• Inventors: Arenson, James W., Thapliyal, Hira V., Gallup, David A.
• Primary Examiner(s): Johnson, III; Henry M
• Assistant Examiner(s): ROANE, AARON F
• Application Number:
  US11/747,862
• Publication Number:
  US 20070265609A1
• Time in Patent Office: 1,481 Days
• Field of Search: 128/898, 601/2, 601/3, 606/27, 606/28, 606 41- 49
• US Class Current: 128/898
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 17/320068 using mechanical vibrations, e.g. ultrasonic A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745
• 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 18/24 with a catheter A61B18/26, A61B18/28 take precedence
• CPC Class Codes: A61B 2017/00106 ultrasonic
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22024 with a part reflecting mechanical vibrations, e.g. for focusing
• CPC Class Codes: A61B 2017/320069 for ablating tissue
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

A cardiac ablation method including the following steps: inserting a treatment catheter into an atrium of a heart, the treatment catheter including an ultrasound emitter; positioning the ultrasound emitter to face heart tissue within the left atrium outside of a pulmonary vein; emitting ultrasound energy from the ultrasound emitter while rotating the ultrasound emitter about a rotation axis; and ablating heart tissue with the ultrasound energy to form a lesion outside of a pulmonary vein.

Claims

1. A cardiac ablation method comprising:

advancing a treatment catheter through a patient'"'"'s vasculature into an atrium of a heart, the treatment catheter comprising an ultrasound emitter disposed near a distal end thereof;

positioning the ultrasound emitter to face heart tissue within the left atrium outside of a pulmonary vein;

ablating the heart tissue with ultrasound energy from the ultrasound emitter to form a first lesion outside of a plurality of left pulmonary veins while rotating the ultrasound emitter about a first rotation axis, wherein the first lesion encircles the ostia of the left pulmonary veins;

repositioning the ultrasound emitter within the left atrium;

ablating the heart tissue with the ultrasound energy to form a second lesion outside of a plurality of right pulmonary veins while rotating the ultrasound emitter about a second rotation axis, wherein the second lesion encircles the ostia of the right pulmonary veins;

ablating the heart tissue with the ultrasound energy to form a connecting lesion while moving the ultrasound emitter between the first lesion and the second lesion, wherein the connecting lesion crosses the first and the second lesions;

ablating the heart tissue with the ultrasound energy to form a transverse lesion while moving the ultrasound emitter between the connecting lesion and the mitral valve, wherein the transverse lesion crosses the connecting lesion and extends toward the mitral valve,

wherein the first lesion, the second lesion, the connecting lesion, and the transverse lesion are all formed without direct contact between the ultrasound emitter and the heart tissue, and wherein the ablating steps are all performed with the ultrasound energy being directed distally from a distally facing surface of the ultrasound emitter, and

wherein each lesion is initially formed on an inner wall of the heart, and the lesions propagate outward toward an outer wall of the heart;

controlling lesion depth by adjusting distance between the ultrasound emitter and the heart tissue with proximal or distal axial movement of the ultrasound emitter relative to the heart tissue;

cooling the ultrasound emitter with fluid wherein the fluid flows past the ultrasound emitter and exits the treatment catheter; and

providing a barrier between the ultrasound emitter and blood in the atrium to prevent the blood from coagulating on the ultrasound emitter, wherein the barrier comprises the fluid.

2. The method of claim 1 wherein the positioning step comprises bending an ultrasound emitter support.

3. The method of claim 1 wherein the positioning step comprises moving the ultrasound emitter parallel to the first or the second rotation axis.

4. The method of claim 1 wherein the positioning step comprises anchoring the treatment catheter.

5. The method of claim 4 wherein the anchoring step comprises placing an anchor against an atrial wall outside of a pulmonary vein.

6. The method of claim 4 wherein the anchoring step comprises placing an anchor within a pulmonary vein.

7. The method of claim 4 wherein the anchoring step comprises placing a plurality of anchors within a plurality of pulmonary veins.

8. The method of claim 4 wherein the anchoring step comprises expanding an anchor within a support catheter.

9. The method of claim 4 wherein either of the rotating steps comprise rotating the treatment catheter about the anchor.

10. The method of claim 1 wherein either of the rotating steps comprise rotating the ultrasound emitter at least 360°

around the rotation axis.

11. The method of claim 1 wherein cooling the emitter or providing the barrier comprise passing the fluid through the ablation catheter and through an exit port adjacent the ultrasound emitter.

12. The method of claim 11 further comprising passing the fluid into a fluid chamber disposed between the ultrasound emitter and the heart tissue.

13. The method of claim 1 further comprising sensing distance between the ultrasound emitter and a tissue surface.

14. The method of claim 13 wherein sensing distance comprises using the ultrasound emitter to sense distance between the emitter and the tissue surface.

15. The method of claim 13 wherein sensing distance comprises sensing distance between the ultrasound emitter and the tissue surface over an intended ablation path prior to either of the ablating steps.

16. The method of claim 15 further comprising repositioning the ultrasound emitter as a result of sensed distance determined in the sensing step.

17. The method of claim 1 further comprising sensing depth of ablation in the heart tissue.

18. The method of claim 17 wherein sensing depth of ablation comprises using the ultrasound emitter to sense depth of ablation in the heart tissue.

19. The method of claim 17 further comprising controlling a speed of rotation of the ultrasound emitter based on sensed depth of ablation.

20. The method of claim 17 further comprising controlling power delivered to the ultrasound emitter based on sensed depth of ablation.

21. The method of claim 1 further comprising sensing thickness of the heart tissue.

22. The method of claim 21 further comprising controlling a speed of rotation of the ultrasound emitter based on sensed thickness of heart tissue.

23. The method of claim 21 further comprising controlling power delivered to the ultrasound emitter based on sensed thickness of heart tissue.

24. The method of claim 1 wherein the step of ablating the first or the second lesion comprises forming a substantially elliptical lesion segment in the heart tissue.

25. The method of claim 1 wherein either of the rotating steps comprises bending a distal portion of the treatment catheter.

26. The method of claim 1 wherein the repositioning step comprises bending a distal portion of the treatment catheter.

27. The method of claim 1 wherein either the connecting lesion or the transverse lesion is substantially linear.

28. The method of claim 1, wherein the energy is directed directly from the emitter to the heart tissue.

29. A cardiac ablation method comprising:

advancing a treatment apparatus through a patient'"'"'s vasculature into an atrium of a heart, the treatment apparatus comprising an ultrasound emitter and an ultrasound emitter support;

positioning the ultrasound emitter to face heart tissue within the left atrium outside of a pulmonary vein;

ablating the heart tissue with ultrasound energy emitted from the ultrasound emitter to form a first lesion outside of a plurality of left pulmonary veins while changing a bend angle in the ultrasound emitter support, wherein the first lesion encircles the ostia of the left pulmonary veins;

repositioning the ultrasound emitter within the left atrium;

ablating the heart tissue with the ultrasound energy to form a second lesion outside of a plurality of right pulmonary veins while changing a bend angle in the ultrasound emitter support, wherein the second lesion encircles the ostia of the right pulmonary veins;

ablating the heart tissue with the ultrasound energy to form a connecting lesion while changing a bend angle in the ultrasound emitter support, wherein the connecting lesion crosses the first and the second lesion;

ablating the heart tissue with the ultrasound energy to form a transverse lesion while changing a bend angle in the ultrasound emitter support, wherein the transverse lesion crosses the connecting lesion and extends toward the mitral valve,

wherein the first lesion, the second lesion, the connecting lesion, and the transverse lesion are all formed without direct contact between the ultrasound emitter and the heart tissue, and wherein the ablating steps are all performed with the ultrasound energy being directed distally from a distally facing surface of the ultrasound emitter, and

wherein each lesion is initially formed on an inner wall of the heart, and the lesions propagate outward toward an outer wall of the heart;

controlling lesion depth by adjusting distance between the ultrasound emitter and the heart tissue with proximal or distal axial movement of the ultrasound emitter relative to the heart tissue;

cooling the ultrasound emitter with fluid wherein the fluid flows past the ultrasound emitter and exits the treatment apparatus; and

providing a barrier between the ultrasound emitter and blood in the atrium to prevent the blood from coagulating on the ultrasound transmitter, wherein the barrier comprises the fluid.

30. The method of claim 29 wherein the positioning step comprises bending an ultrasound emitter support.

31. The method of claim 29 wherein the positioning step comprises anchoring the treatment catheter.

32. The method of claim 29 wherein the ablating step comprises forming a substantially linear lesion in the heart tissue.

33. The method of claim 29 wherein the ablating step forming either the first or the second lesion comprises forming a substantially elliptical lesion segment in the heart tissue.

34. The method of claim 29 wherein either the connecting lesion or the transverse lesion is substantially linear.

35. The method of claim 29 wherein the energy is directed directly from the emitter to the heart tissue.