Radio frequency pulmonary vein isolation

• US 20030144658A1
• Filed: 01/31/2002
• Published: 07/31/2003
• Est. Priority Date: 01/31/2002
• Status: Active Grant

• Current Assignee: Biosense, Inc. (Cardinal Health, Inc.)
• Original Assignee: Biosense, Inc. (Cardinal Health, Inc.)
• Inventors: Govari, Assaf, Schwartz, Yitzhack, Levin, Michael, Yaron, Uri, Leatham, Marcia
• Granted Patent: US 6,814,733 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• 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 2017/00867 shape memory effect
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00261 arranged in a line
• CPC Class Codes: A61B 2018/00375 Ostium, e.g. ostium of pulmonary vein or artery
• CPC Class Codes: A61B 2018/1435 Spiral
• CPC Class Codes: C08L 2201/12 Shape memory

Abstract

A catheter introduction apparatus provides a radially expandable helical coil as a radiofrequency emitter. In one application the emitter is introduced percutaneously, and transseptally advanced to the ostium of a pulmonary vein. The emitter is radially expanded, which can be accomplished by inflating an anchoring balloon about which the emitter is wrapped, in order to cause the emitter to make circumferential contact with the inner wall of the pulmonary vein. The coil is energized by a radiofrequency generator, and a circumferential ablation lesion is produced in the myocardial sleeve of the pulmonary vein, which effectively blocks electrical propagation between the pulmonary vein and the left atrium.

Claims

1. A method for electrically isolating a cardiac chamber, comprising the steps of:

introducing a coil into a pulmonary vein proximate an ostium of said pulmonary vein, wherein a principal axis of said coil is substantially aligned coaxially with said pulmonary vein;

circumferentially engaging said coil with an inner wall of said pulmonary vein to define a circumferential region of contact between said coil and said pulmonary vein; and

while maintaining said circumferential region of contact, conducting radiofrequency energy from said coil to said circumferential region of contact to ablate tissue in an ablation region of said pulmonary vein.

2. The method according to claim 1, wherein said step of circumferentially engaging said coil is performed by radially expanding said coil.

3. The method according to claim 2, wherein said coil is constructed of a shape memory alloy.

4. The method according to claim 3, further comprising varying a temperature of said coil to alter a configuration thereof.

5. The method according to claim 4, wherein while performing said step of varying said temperature, said coil radially expands responsive to a shape memory thereof.

6. The method according to claim 2, wherein a proximal segment of said coil is more radially expanded than a distal segment thereof.

7. The method according to claim 6, wherein said step of radially expanding comprises tapering said coil.

8. The method according to claim 1, wherein said step of circumferentially engaging said coil is performed by axially expanding said coil.

9. The method according to claim 8, wherein said step of axially expanding said coil is performed by differentially heating segments of said coil.

10. The method according to claim 9, wherein said step of differentially heating is performed by passing different amounts of current through different ones of said segments of said coil.

11. The method according to claim 9, wherein said step of differentially heating is performed by inductive heating.

12. The method according to claim 9, wherein said step of differentially heating is performed by the steps of:

subjecting said coil to a single electromagnetic influence for heating thereof; and

conducting a coolant to selected ones of said segments of said coil.

13. The method according to claim 1, wherein a width dimension of said ablation region is at least as large as a pitch of said coil.

14. The method according to claim 1, wherein said step of introducing comprises the steps of:

transferring said coil into a heart through an interatrial septum thereof; and

while transferring said coil through said interatrial septum, conducting radiofrequency energy a second time from said coil into said interatrial septum to ablate tissue of said interatrial septum.

15. The method according to claim 14, wherein said step of conducting radiofrequency energy said second time is performed until a sufficient amount of said tissue of said interatrial septum has been ablated to accommodate a passage of said coil therethrough.

16. The method according to claim 1, wherein said coil is constructed of a biodegradable material.

17. The method according to claim 1, wherein said step of conducting radiofrequency energy is performed in a single continuous application.

18. The method according to claim 1, wherein said step of circumferentially engaging said coil is performed by the steps of:

disposing said coil about an anchoring balloon; and

inflating said anchoring balloon to radially expand said coil.

19. The method according to claim 18, wherein following performance of said step of inflating said anchoring balloon, a proximal segment of said anchoring balloon has a larger diameter than a distal segment thereof.

20. The method according to claim 19, wherein said anchoring balloon is bilobate.

21. The method according to claim 19, wherein said anchoring balloon is pyriform.

22. A method for ablating tissue, comprising the steps of:

providing a coil that is constructed of a shape memory material;

introducing said coil into a hollow viscus;

circumferentially engaging said coil with an inner wall of said viscus to define a circumferential region of contact between said coil and said inner wall; and

while maintaining said circumferential region of contact, conducting radiofrequency energy from said coil to said circumferential region of contact to ablate tissue therein.

23. The method according to claim 22, wherein said step of circumferentially engaging said coil is performed by radially expanding said coil.

24. The method according to claim 23, wherein said coil is constructed of a shape memory alloy.

25. The method according to claim 23, wherein said step of providing said coil includes forming zigzag folds in a plurality of windings thereof.

26. The method according to claim 23, wherein a proximal segment of said coil is more radially expanded than a distal segment thereof.

27. The method according to claim 26, further comprising varying a temperature of said coil to alter a configuration thereof.

28. The method according to claim 27, wherein while performing said step of varying said temperature, said coil radially expands responsive to a shape memory thereof.

29. The method according to claim 26, wherein said step of radially expanding comprises tapering said coil.

30. The method according to claim 22, wherein said step of circumferentially engaging said coil is performed by axially expanding said coil.

31. The method according to claim 30, wherein said step of axially expanding said coil is performed by differentially heating segments of said coil.

32. The method according to claim 31, wherein said step of differentially heating is performed by passing different amounts of current through different ones of said segments of said coil.

33. The method according to claim 31, wherein said step of differentially heating is performed by inductive heating.

34. The method according to claim 31, wherein said step of differentially heating is performed by the steps of:

subjecting said coil to a single electromagnetic influence for heating thereof, and

conducting a coolant to selected ones of said segments of said coil.

35. The method according to claim 22, wherein said coil is constructed of a biodegradable material.

36. The method according to claim 22, wherein said step of conducting radiofrequency energy is performed in a single continuous application.

37. The method according to claim 22, wherein said step of circumferentially engaging said coil is performed by the steps of:

disposing said coil about an anchoring balloon; and

inflating said anchoring balloon to radially expand said coil.

38. The method according to claim 37, wherein following performance of said step of inflating said anchoring balloon, a proximal segment of said anchoring balloon has a larger diameter than a distal segment thereof.

39. The method according to claim 38, wherein said anchoring balloon is bilobate.

40. The method according to claim 38, wherein said anchoring balloon is pyriform.