Apparatus and methods for intrabody thermal treatment

• US 6,605,084 B2
• Filed: 03/23/2001
• Issued: 08/12/2003
• Est. Priority Date: 03/24/2000
• Status: Expired due to Term

• Current Assignee: Recor Medical, Inc. (Otsuka Holdings Company Limited)
• Original Assignee: Transurgical, Inc.
• Inventors: Fjield, Todd, Reisinger, Keith A., Lopath, Patrick David, Acker, David E.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US09/815,863
• Publication Number:
  US 20020002371A1
• Time in Patent Office: 872 Days
• Field of Search: 606/7, 606/27, 606/28, 606/96, 600/437, 600/459, 600/462, 600/463, 600/466, 600/467, 600/472, 607/96, 607/113
• US Class Current: 606/28
• 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 2017/00243 cardiac
• CPC Class Codes: A61B 2017/22028 arrays, e.g. phased arrays
• CPC Class Codes: A61B 2017/22054 with two balloons
• CPC Class Codes: A61B 2017/22069 Immobilising; Stabilising
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

A treatment catheter (10) carries an elongated ultrasonic emitter (20) extending in the lengthwise direction of the catheter. The array is flexible in all directions transverse to the lengthwise direction. The treatment catheter is inserted into a chamber of the heart and brought to a desired configuration such as a substantially closed loop. The treatment catheter is then biased into engagement with the wall of the heart by an expansible balloon (62) or other expansible structure, which may be carried on a separate stabilizer catheter (60). While the treatment catheter is engaged with the heart wall, the array is actuated to ablate tissue along a path having a shape corresponding to the configuration of the treatment catheter.

Claims

1. A medical device comprising an elongated catheter body with proximal and distal directions in its direction of elongation and an elongated ultrasonic transducer array extending in said proximal and distal directions, said catheter body and said transducer array being flexible in all directions transverse to said proximal and distal directions.

2. A medical device as claimed in claim 1 wherein said transducer array is substantially in the form of a helix surrounding a region of said catheter body.

3. An elongated ultrasonic transducer array having lengthwise directions, said array including:

(a) a sheetlike element having a first fold extending in said lengthwise directions and defining a first pair of adjacent regions on opposite sides of the fold, said regions being non-parallel with one another, at least one of said regions being an active region;

(b) a plurality of ultrasonic transducer elements disposed on or formed integrally with said sheetlike element, said sheetlike element having notches in each of said regions extending along axes transverse to said first fold at locations spaced apart from one another in said lengthwise direction and subdividing each of said regions into panes, the notches in each region of said first pair being offset in said lengthwise direction from the notches in the other region of said first pair, said panes of each region of said first pair having hinge zones aligned with the axes of notches in the other region of said first pair, said sheetlike element being flexible at least in said hinge zones, whereby the array is free to bend in directions transverse to said lengthwise directions.

4. An array as claimed in claim 3 wherein each region of said first pair has a outlying boundary remote from said first fold and the notches in each said region extend from the outlying boundary of that region, to and across said first fold and into the other region of said first pair, but do not extend to the outlying boundary of the other region of said first pair.

5. An array as claimed in claim 3 wherein said sheetlike element has one or more electrical conductors thereon, said conductors extending lengthwise along said sheetlike element in a zigzag pattern so that said conductors pass through the hinge regions of said panes and around said notches.

6. An array as claimed in claim 3 wherein each region of said first pair has a outlying boundary remote from said first fold and the notches in each region extend from the outlying boundary of that region, to and across said first fold and into the other region of said first pair, but do not extend to the outlying boundary of the other region of said first pair.

7. A method of applying energy within the body of a living subject comprising the steps of:

(a) placing a device including hollow enclosure within the body of the subject;

(b) providing at least one fluid medium within the hollow enclosure;

(c) directing energy onto an internal structure of the body through the fluid in said hollow enclosure so that said energy is refracted by one said fluid medium in the enclosure; and

(d) imaging the body of the subject while said enclosure is disposed in the body of the subject and while the hollow enclosure is filled with one said fluid medium, the fluid disposed in said enclosure having response to said imaging step different from the response of bodily tissue to said imaging step, whereby the fluid-filled enclosure will be seen in contrast in an image resulting from said imaging step.

8. A method as claimed in claim 7 wherein said step of providing at least one fluid medium is performed so that the same fluid medium is disposed in said enclosure during said step of directing energy and during said imaging step.

9. A method as claimed in claim 7 wherein the fluid disposed in said enclosure during said imaging step includes one or more paramagnetic transition metal ions and said imaging step includes magnetic resonance imaging.

10. A method as claimed in claim 7 wherein said step of directing energy includes directing ultrasonic waves through said enclosure so that said ultrasonic waves are refracted by the fluid in said enclosure.

11. Apparatus for applying thermal treatment to tissue of an internal organ of a living subject comprising:

(a) one or more catheters;

(b) an elongated energy emitter carried on one of said one or more catheters, said elongated energy emitter being adapted to assume a desired shape when disposed within said organ;

(c) an expansible positioning structure carried on one of said one or more catheters, said energy emitter in said desired shape extending over said expansible positioning structure so that said expansible positioning structure can bias said elongated energy emitter against a wall of the organ, whereby when said positioning element and said energy emitter are in an operative condition, said energy emitter in said desired shape extends along an elongated path having a shape corresponding to said desired shape on such interior wall, said energy emitter being operative to emit energy at a plurality of locations along its length so as to heat tissue surrounding said organ at a plurality of locations along said path.

12. Apparatus as claimed in claim 11 wherein said energy emitter is adapted to emit energy substantially simultaneously at said plurality of locations along its length to thereby heat tissue at a plurality of locations along said path substantially simultaneously.

13. Apparatus as claimed in claim 11 wherein said expansible positioning element and said energy emitter are adapted for operation within a heart chamber of a mammalian subject, said expansible positioning element biasing said energy emitting element against the interior wall of such heart chamber in said operative condition.

14. Apparatus as claimed in claim 11 wherein said expansible positioning structure includes a balloon.

15. Apparatus as claimed in claim 11 wherein said elongated energy emitter includes one or more ultrasonic transducer elements.

16. Apparatus as claimed in claim 15 wherein said ultrasonic transducer elements include a polymeric electromechanical transduction film.

17. Apparatus as claimed in claim 16 wherein said electromechanical transduction film is a polymeric piezoelectric film.

18. Apparatus as claimed in claim 15 wherein said one or more ultrasonic transducer elements includes an elongated ultrasonic transducer array having a lengthwise axis, said array being flexible in directions transverse to its lengthwise axis and extending in said desired curved shape in said operative condition.

19. Apparatus as claimed in claim 18 wherein said ultrasonic transducer array includes active emitting regions facing generally in a radially-outward direction transverse to the lengthwise axis of the array.

20. Apparatus as claimed in claim 11 wherein said energy emitter is formed separately from said expansible positioning structure, so that said energy emitter can assume said desired shape before it is biased against the wall of the organ.

21. Apparatus as claimed in claim 20 wherein said energy emitter is adapted to assume a curved shape.

22. Apparatus as claimed in claim 21 wherein said energy emitted is adapted to form a loop, whereby said path will be generally in the form of a loop.

23. Apparatus as claimed in claim 11 wherein said one or more catheters includes a treatment catheter carrying said emitting device, said emitting device extending lengthwise along said treatment catheter adjacent the distal end thereof.

24. Apparatus as claimed in claim 23 wherein said anchor includes an expandable anchor element movable between a collapsed condition and an expanded condition.

25. Apparatus as claimed in claim 23 wherein said expansible positioning structure is movable relative to said treatment catheter while said treatment catheter is in said operative condition.

26. Apparatus as claimed in claim 23 wherein said one or more catheters include a holding structure separate from said treatment catheter, said holding structure carrying said expansible positioning element.

27. Apparatus as claimed in claim 26 wherein said holding structure includes a stabilizer catheter and an anchor linked to said stabilizer catheter, said anchor being adapted to engage an anatomical structure in or adjacent said organ.

28. Apparatus as claimed in claim 27 wherein said expansible positioning element is mounted on said stabilizer catheter.

29. Apparatus as claimed in claim 27 wherein said expansible positioning element is movable relative to said anchor while said anchor is engaged with said anatomical structure.

30. A method of applying thermal treatment to tissue of an internal organ comprising:

(a) inserting an elongated energy emitter into the interior of the internal organ and bringing the energy emitter to a desired shape in a desired position relative to the organ;

(b) inserting an expansible positioning element into the interior of the organ; and

(c) expanding said positioning structure so that the energy emitter is disposed between the positioning structure and the wall of the organ and said positioning structure biases said energy emitter against the interior wall of the organ, whereby said energy emitter in said desired shape extends along an elongated path having a shape corresponding to said desired curved shape on such interior wall; and

(d) while said energy emitter is extending along said path, actuating said energy emitter to emit energy at a plurality of locations along its length so as to heat tissue at a plurality of locations along such path.

31. A method as claimed in claim 30 wherein said energy emitter is brought at least approximately to said desired shape and at least approximately to said desired position before said positioning structure is fully expanded.

32. A method as claimed in claim 31 wherein said desired shape is a curved shape.

33. A method as claimed in claim 32 wherein said desired shape a closed or nearly closed loop.

34. A method as claimed in claim 30 wherein said energy emitter emits energy substantially simultaneously at said plurality of locations along its length to thereby heat tissue at a plurality of locations along said path substantially simultaneously.

35. A method as claimed in claim 34 wherein said energy emitter includes an array of one or more ultrasonic transducer elements, said array extending lengthwise along the device, said transducer elements emitting ultrasonic energy at said plurality of locations.

36. A method as claimed in claim 35 wherein said step of inserting said energy emitter includes the step of advancing the array lengthwise through a tubular anatomical structure and then deforming the array in directions transverse to its lengthwise direction to said desired shape.

37. A method as claimed in claim 35 further comprising focusing ultrasonic energy emitted by said transducer elements onto a elongated focal region extending generally parallel to said path.

38. A method as claimed in claim 37 wherein said focal region is disposed on or in the wall of said organ.

39. A method as claimed in claim 38 further comprising varying the focus of said ultrasonic energy so as to move said focal region towards or away from said array and thereby position said focal region deeper or shallower within the wall of said organ while said array remains substantially in position along said path.

40. A method as claimed in any one of claim 30 or claim 32 or claim 36 wherein said internal organ is the heart, and wherein said heating is effective to kill tissue within the wall of a chamber of the heart.

41. A method as claimed in claim 40 wherein said heating is effective to kill tissue substantially through the wall of the heart.

42. A method as claimed in claim 40 further comprising the step of moving said expansible positioning element toward said emitter so as to bring the positioning element into engagement with the emitter after said emitter is at least approximately in said desired shape and desired position.

43. A method as claimed in claim 40 wherein said path at least partially encircles the ostium of at least one blood vessel opening to such chamber of the heart.

44. A method as claimed in claim 43 wherein said path substantially completely encircles said at least one ostium.

45. A method as claimed in claim 40 further comprising the step of placing at least one anchoring element within at least one said blood vessel, said at least one anchoring element being connected to said positioning structure at least while the positioning structure is biasing the energy-emitter against the wall of the heart so that said anchoring element tends to retain the positioning structure and the emitter in position.

46. A method as claimed in claim 45 wherein said anchoring element and said positioning structure are both attached to a stabilizer catheter, the method further comprising the step of placing said stabilizer catheter so that the anchoring element is disposed within said blood vessel and the positioning structure is disposed within the chamber, and then engaging the anchoring element with the wall of the blood vessel and expanding the positioning structure.

47. An array as claimed in claim 46 wherein said ultrasonic transducer elements include polymeric piezoelectric film overlying or formed integrally with said sheetlike element.

48. A medical device comprising an elongated catheter body with proximal and distal directions in its direction of elongation, and an array as claimed in claim 39, the lengthwise directions of said array and said fold extending in the proximal and distal directions of said body, said active region being disposed on or constituting an outwardly-facing surface of said body and extending in lateral directions transverse to said lengthwise directions.

49. A device as claimed in claim 48 wherein said regions of said sheetlike element including at least one additional region extending from said first fold into the interior of said body in a direction transverse to said lateral and lengthwise directions.

50. A device as claimed in claim 48 wherein said sheetlike element includes first and second active regions disposed on opposite sides of said first fold, said transducer elements being disposed in both of said active regions.

51. A device as claimed in claim 50 wherein said active regions slope radially outwardly in opposite lateral directions away from said first fold whereby said transducer elements on said first and second regions face toward a common elongated focal region outside of said body but generally parallel thereto.

52. A device as claimed in claim 50 wherein said first and second active regions join one another at said first fold.

53. A device as claimed in claim 50 wherein said sheetlike element includes second and third folds extending generally parallel to said first fold, a first additional region joining said first active region at said first fold and a second additional region joining said first additional region at said second fold, said second active region joining said second additional region at said third fold, whereby said second active region and said second additional region constitute a second pair of mutually adjacent regions, said additional regions extending into the interior of said body.

54. A device as claimed in claim 53 wherein said sheetlike element has notches in each of said regions extending transverse to said folds and transverse to said lengthwise direction, the notches in said additional regions being aligned with one another in said lengthwise direction, the notches in said second active region being offset in said lengthwise direction from the notches in said second additional region.

60. A medical device as claimed in claim 48 or claim 55 wherein said catheter body is hollow and defines a catheter bore, said catheter bore being filled with a catheter bore fluid when said device is in an operative condition, at least said portion of said catheter body being deformable so as to vary the configuration of said array by varying the pressure of said catheter bore fluid.

55. A medical device comprising:

(a) a first elongated catheter body having an exterior surface and having proximal and distal directions;

(b) a distributed array of one or more ultrasonic transducer elements disposed on or constituting a portion of said exterior surface of said first body and extending in said proximal and distal directions; and

(c) an elongated lens overlying said array of transducer elements and extending in said proximal and distal directions, said lens being adapted to focus ultrasonic emissions from said transducer elements into a elongated focal region outside of said body but generally parallel thereto, said body, lens and array being flexible in directions transverse to said proximal and distal directions.

56. A medical device as claimed in claim 55 wherein said lens includes a hollow enclosure extending in said proximal and distal directions, said enclosure being filled with a lens fluid when the device is in an operative condition.

57. A medical device as claimed in claim 56 wherein said hollow enclosure is deformable, whereby the shape of said lens can be varied by varying the pressure of said lens fluid.

58. A medical device as claimed in claim 56 wherein said lens fluid includes an X-ray or magnetic-resonance contrast medium.

59. A medical device as claimed in claim 56 further comprising ports communicating with said hollow enclosure proximal to and distal to said transducer array so that a fluid can be circulated through said hollow enclosure to control the temperature of said transducer array.