Composite structures and methods for ablating tissue to form complex lesion patterns in the treatment of cardiac conditions and the like

• US 6,241,754 B1
• Filed: 11/18/1996
• Issued: 06/05/2001
• Est. Priority Date: 10/15/1993
• Status: Expired due to Term

• Current Assignee: EP Technology (Boston Scientific Corporation)
• Original Assignee: EP Technology (Boston Scientific Corporation)
• Inventors: McGee, David L., Swanson, David K., Fleischman, Sidney D., Kordis, Thomas F.
• Primary Examiner(s): Casler, Brian L.
• Application Number:
  US08/752,162
• Time in Patent Office: 1,660 Days
• Field of Search: 607/99, 607/101, 607/116, 607/119, 607/122, 607/125, 607/126, 607/127, 607/148, 606/32, 606/41, 606/45, 606/47, 600/373
• US Class Current: 607/99
• 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 2017/003 Steerable
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• 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 2018/00267 having a basket shaped structure
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1437 whereby the windings of the spiral touch each other such as to create a continuous surface
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1497 Electrodes covering only part of the probe circumference

Abstract

A method of ablating tissue in the heart to treat atrial fibrillation introduces into a selected atrium an energy emitting element. The method exposes the element to a region of the atrial wall and applies ablating energy to the element to thermally destroy tissue. The method forms a convoluted lesion pattern comprising elongated straight lesions and elongated curvilinear lesions. The lesion pattern directs electrical impulses within the atrial myocardium along a path that activates the atrial myocardium while interrupting reentry circuits that, if not interrupted, would cause fibrillation. The method emulates the surgical maze procedure, but lends itself to catheter-based procedures that do not require open heart surgical techniques. A composite structure for performing the method is formed using a template that displays in planar view a desired lesion pattern for the tissue. An array of spaced apart element is laid on the template. Guided by the template, energy emitting and non-energy emitting zones are formed on the elements. By overlaying the elements, the composite structure is formed, which can be introduced into the body to ablate tissue using catheter-based, vascular access techniques.

Claims

1. A method of creating a lesion pattern in heart tissue, comprising the steps of:

introducing an elongate element, having an energy emitting portion that can be flexed along its length from a generally straight shape into a curvilinear shape, into the heart;

positioning the element in a first position adjacent to a first surface within the heart while maintaining the energy emitting portion in a desired shape;

applying ablating energy to the energy emitting portion while maintaining the element in the first position to form an elongate lesion having a shape corresponding to the shape of the element;

changing at least one of the shape of the element and the position of the element within heart; and

forming a convoluted lesion pattern by repeating the positioning, applying and changing steps.

2. A method as claimed in claim 1, wherein the step of forming a convoluted lesion pattern comprises forming a lesion pattern including elongated straight lesions and elongated curvilinear lesions by repeating the positioning, applying and changing steps.

3. A method as claimed in claim 1, wherein the step of introducing an elongate element into the heart comprises introducing an elongate element into an atrium.

4. A method as claimed in claim 3, wherein the step of forming a convoluted lesion pattern comprises forming a lesion pattern including elongated straight lesions and elongated curvilinear lesions that direct electrical impulses within the atrial myocardium along a path that activates the atrial myocardium while interrupting reentry circuits that, if not interrupted, would cause fibrillation, by repeating the positioning, applying and changing steps.

5. A method as claimed in claim 1, wherein in the step of applying ablating energy comprises applying radiofrequency electromagnetic energy.

6. A method as claimed in claim 1, further comprising the step of:

introducing a viewing probe into the heart to monitor the position of the element during the step of positioning the element.

7. A method as claimed in claim 1, wherein the step of introducing the element into the heart comprises introducing the element through a vascular approach without opening the heart.

8. A method of creating a lesion pattern in heart tissue, comprising the steps of:

introducing a bendable spline having an energy emitting element into the heart, the bendable spline having a normally curvilinear configuration and being collapsible in response to a compression force;

positioning the bendable spline in a first position adjacent to a first surface within the heart;

applying ablating energy to the energy emitting portion while maintaining the bendable spline in the curvilinear configuration to form an elongate lesion having a shape corresponding to the shape of the energy emitting region;

changing the position of the bendable spline within heart; and

forming a convoluted lesion pattern by repeating the positioning, applying and changing steps.

9. A method as claimed in claim 8, wherein the step of introducing a bendable spline into the heart comprises collapsing the bendable spline, inserting the bendable spline into the heart, and expanding the bendable spline into the curvilinear configuration after the bendable spline is within the heart.

10. A method as claimed in claim 9, wherein the step of inserting the bendable spline into the heart comprises introducing the bendable spline through a vascular approach without opening the heart.

11. A method as claimed in claim 8, wherein the step of forming a convoluted lesion pattern comprises forming a lesion pattern including elongated straight lesions and elongated curvilinear lesions by repeating the positioning, applying and changing steps.

12. A method as claimed in claim 8, wherein the step of introducing a bendable spline into the heart comprises introducing a bendable spline into an atrium.

13. A method as claimed in claim 12, wherein the step of forming a convoluted lesion pattern comprises forming a lesion pattern including elongated straight lesions and elongated curvilinear lesions that direct electrical impulses within the atrial myocardium along a path that activates the atrial myocardium while interrupting reentry circuits that, if not interrupted, would cause fibrillation, by repeating the positioning, applying and changing steps.

14. A method as claimed in claim 8, wherein in the step of applying ablating energy comprises applying radiofrequency electromagnetic energy.

15. A method as claimed in claim 8, further comprising the step of:

introducing a viewing probe into the heart to monitor the position of the bendable spline during the step of positioning the bendable spline.

16. A method as claimed in claim 8, wherein the step of introducing a bendable spline into the heart comprises introducing a plurality of bendable splines arranged in a three-dimensional array into the heart.

17. A method as claimed in claim 8, wherein the step of introducing a bendable spline into the heart comprises introducing a loop structure into the heart.

18. An apparatus for ablating tissue, comprising:

a guide element defining a distal end and a proximal end;

a substantially circular support body associated with the distal end of the guide element;

a plurality of electrically conductive regions carried by the substantially circular support body with a plurality of non-conducting regions therebetween;

an indifferent electrode in spaced relation to the guide element and adapted to be located on the exterior of the body; and

a source of ablation energy operably connected to the electrically conducting regions and adapted to simultaneously supply energy to the plurality of electrically conducting regions such that each of the electrically conductive regions transmits energy through a contacted tissue area to the indifferent electrode.

19. An apparatus as claimed in claim 18, wherein a portion of the substantially circular support body abuts the distal end of the guide element.

20. A method of creating a lesion pattern in heart tissue, comprising the steps of:

introducing an element into the heart having a lesion creating portion that can be flexed along its length from a generally straight shape into a curvilinear shape;

positioning the element in a first position adjacent to a first surface within the heart while maintaining the lesion creating portion in a desired shape;

creating a lesion with the lesion creating portion while maintaining the element in the first position to form an elongate lesion having a shape corresponding to the shape of the element;

changing at least one of the shape of the element and the position of the element within heart; and

forming a convoluted lesion pattern by repeating the positioning, creating and changing steps.

21. A method as claimed in claim 20, wherein the step of forming a convoluted lesion pattern comprises forming a lesion pattern including elongated straight lesions and elongated curvilinear lesions that direct electrical impulses within the atrial myocardium along a path that activates the atrial myocardium while interrupting reentry circuits that, if not interrupted, would cause fibrillation, by repeating the positioning, actuating and changing steps.

22. A method as claimed in claim 20, wherein the step of introducing an element having a lesion creating portion comprises introducing an element having an energy emitting portion and the step of creating a lesion with the lesion creating portion comprises transmitting radiofrequency electromagnetic energy through the lesion creating portion.

23. A method as claimed in claim 20, wherein the step of introducing the element into the heart comprises introducing the element through a vascular approach without opening the heart.

24. A method of creating a lesion in heart tissue, comprising the steps of:

introducing a substantially circular energy emitting structure into the heart;

positioning the energy emitting structure such that it abuts an orifice within the heart; and

applying ablating energy to the heart tissue with the energy emitting structure while the energy emitting structure is abutting the orifice to form a continuous elongate lesion having a substantially circular shape.

25. A method as claimed in claim 24, wherein the orifice comprises one of the superior vena cava, the inferior vena cava and a pulmonary vein.

26. A method as claimed in claim 24, wherein the step of introducing a substantially circular energy emitting structure into the heart comprises collapsing the substantially circular energy emitting structure, inserting the substantially circular energy emitting structure into the heart, and expanding the substantially circular energy emitting structure after the substantially circular energy emitting structure is within the heart.

27. A method as claimed in claim 26, wherein the step of introducing a substantially circular energy emitting structure into the heart comprises inserting the substantially circular energy emitting structure through a vascular approach without opening the heart.

28. A method as claimed in claim 24, wherein the step of introducing a substantially circular energy emitting structure into the heart comprises introducing a bendable loop structure that supports at least one energy emitting element into the heart.

29. A method as claimed in claim 24, wherein the step of introducing a substantially circular energy emitting structure into the heart comprises introducing a bendable loop structure that supports a plurality of spaced energy emitting elements into the heart.

30. A method as claimed in claim 24, wherein the step of introducing a substantially circular energy emitting structure into the heart comprises introducing an annular structure that supports at least one energy emitting element into the heart.

31. A method as claimed in claim 24, wherein the step of introducing a substantially circular energy emitting structure into the heart comprises introducing an inflatable structure that supports at least one energy emitting element into the heart.

32. A method as claimed in claim 24, wherein the step of positioning the energy emitting structure comprises positioning the energy emitting structure such that it encircles the orifice.

33. A method as claimed in claim 24, wherein the step of applying ablating energy to the heart tissue comprises applying electromagnetic energy to the heart tissue.

34. A method of creating a lesion in heart tissue, comprising the steps of:

introducing a tissue ablation structure having a shape corresponding to an orifice within the heart;

positioning the tissue ablation structure such that it abuts the orifice; and

ablating tissue with the tissue ablation structure while the tissue ablation structure is abutting the orifice to form a continuous elongate lesion around the orifice.

35. A method as claimed in claim 34, wherein the orifice comprises one of the superior vena cava, the inferior vena cava and a pulmonary vein.

36. A method as claimed in claim 34, wherein the step of introducing a tissue ablation structure into the heart comprises collapsing the tissue ablation structure, inserting the tissue ablation structure into the heart, and expanding the tissue ablation structure after the tissue ablation structure is within the heart.

37. A method as claimed in claim 34, wherein the step of introducing a tissue ablation structure into the heart comprises inserting the tissue ablation structure through a vascular approach without opening the heart.

38. A method as claimed in claim 34, wherein the step of introducing a tissue ablation structure into the heart comprises introducing a bendable loop structure that supports at least one tissue ablation element into the heart.

39. A method as claimed in claim 34, wherein the step of introducing a tissue ablation structure into the heart comprises introducing an annular structure that supports at least one tissue ablation element into the heart.

40. A method as claimed in claim 34, wherein the step of introducing a tissue ablation structure into the heart comprises introducing an inflatable structure that supports at least one tissue ablation element into the heart.

41. A method as claimed in claim 34, wherein the step of positioning the tissue ablation structure comprises positioning the tissue ablation structure such that it encircles the orifice.

42. A method as claimed in claim 34, wherein the step of ablating tissue comprises applying ablating energy to the tissue.

43. A method as claimed in claim 34, wherein the step of ablating tissue comprises applying electromagnetic ablating energy to the tissue.

44. A method as claimed in claim 34, wherein the step of ablating tissue comprises cooling the tissue.

45. An apparatus for creating a lesion in tissue, comprising:

a guide element defining a distal end and a proximal end;

a support body carried by the guide element having a size and shape adapted to engage a substantially circular region of tissue associated with an orifice within the heart; and

a tissue ablation device supported on the support body and adapted to form a continuous lesion having a substantially circular shape in the substantially circular region of tissue.

46. An apparatus as claimed in claim 45, wherein the support body comprises a collapsible loop structure.

47. An apparatus as claimed in claim 45, wherein the support body comprises an inflatable structure.

48. An apparatus as claimed in claim 45, wherein the support body comprises an annular structure.

49. A apparatus as claimed in claim 45, wherein the support body has a size and shape adapted to engage one of the superior vena cava, the inferior vena cava and a pulmonary vein.

50. An apparatus as claimed in claim 45, wherein the tissue ablation device comprises an energy emitting structure.

51. An apparatus as claimed in claim 50, wherein the energy emitting structure comprises a plurality of spaced conductive regions.

52. An apparatus as claimed in claim 50, wherein the energy emitting structure comprises a continuous conductive region.

53. An apparatus as claimed in claim 50, wherein the energy emitting structure is adapted to emit electromagnetic energy.