Ablation catheter and method for isolating a pulmonary vein

• US 6,572,612 B2
• Filed: 10/11/2001
• Issued: 06/03/2003
• Est. Priority Date: 04/05/1999
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Min, Xiaoyi, Mehra, Rahul, Francischelli, David E., Flickinger, William J., Stewart, Mark T.
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US09/975,789
• Publication Number:
  US 20020022839A1
• Time in Patent Office: 600 Days
• Field of Search: 606/41, 606/49, 607/99, 607/113, 607/122, 600/374, 600/381
• 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 2017/00044 Sensing electrocardiography, i.e. ECG
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/1435 Spiral

Abstract

A catheter assembly and method for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter assembly includes a catheter body and at least one electrode. The catheter body includes a proximal portion, an intermediate portion and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and forms a substantially closed loop transverse to the longitudinal axis. The at least one electrode is disposed along the loop. With this configuration, the loop is axially directed into contact with the chamber wall about the vessel ostium. Upon energization, the electrode ablates a continuous lesion pattern about the vessel ostium, thereby electrically isolating the vessel from the chamber.

Claims

1. A catheter assembly for treatment of cardiac arrhythmia, the catheter assembly comprising:

a catheter body having a proximal portion and a distal portion and defining a longitudinal axis;

a wire basket connected to an exterior of the catheter body along the distal portion thereof, the wire basket being selectively transitionable between a retracted position and an expanded position; and

a plurality of electrodes maintained by the wire basket;

wherein the catheter assembly is configured such that in the expanded position, the wire basket positions the electrodes to define an ablation loop that is transverse to the longitudinal axis and adapted to encompass a pulmonary vein ostium, and further comprising a cooling source fluidly coupled to a portion of the wire basket.

2. The catheter assembly of claim 1, further comprising a plurality of wire struts each supporting at least one of the plurality of electrodes.

3. The catheter assembly of claim 2, wherein each of the wire struts is tubular.

4. The catheter assembly of claim 2, wherein at least one electrode associated with a respective wire strut is positioned distal a center point of the respective wire strut.

5. The catheter assembly of claim 2, wherein the expandable basket structure further includes a proximal collar and a distal collar coupling the wire struts to the catheter body.

6. The catheter assembly of claim 5, wherein the proximal collar is slidable relative to the distal collar so that the expandable basket structure expands when the proximal collar approaches the distal collar.

7. The catheter assembly of claim 1, further comprising a temperature sensing element operatively coupled to at least one of the wire struts.

8. The catheter assembly of claim 7, wherein the temperature sensing element is electrically coupled to provide closed loop feedback of the temperature of affected tissue dining an ablation procedure.

9. The catheter assembly of claim 7, wherein the temperature sensing element is integrated into one of the plurality of electrodes.

10. The catheter assembly of claim 1, further comprising:

an elongated portion of the catheter assembly configured as a locating device disposed substantially in alignment with the center longitudinal axis and connected to the catheter body distal the expandable basket structure, the locating device adapted to center the ablation loop relative to an ostium.

11. A catheter assembly for treatment of cardiac arrhythmia, the catheter assembly comprising:

a catheter body having a proximal portion and a distal portion and defining a central longitudinal axis;

an expandable basket structure coupled around the catheter body and spaced from a distal end of the catheter body and wherein opposing ends of the expandable basket structure are coupled to the catheter body and an intermediate portion of the expandable basket structure is spaced from the catheter body and said intermediate portion being selectively circumferentially expanded and contracted between a retracted position and an expanded position relative to the central longitudinal axis; and

a plurality of electrodes operatively coupled to the expandable basket structure;

wherein the catheter assembly is configured such that in the expanded position, the expandable basket structure positions the electrodes to define an ablation loop that is transverse to the longitudinal axis and adapted to encompass a pulmonary vein ostium and wherein the ablation loop has a central loop axis aligned with the central longitudinal axis and further comprising an inflatable balloon coupled to the catheter body distal the expandable basket structure.

12. The catheter assembly of claim 11, wherein the ablation loop is adapted to ablate a lesion pattern about a pulmonary vein ostium upon activation of the electrodes.

13. The catheter assembly of claim 11, further comprising:

a mapping electrode coupled to the catheter body and disposed distal the expandable basket structure.

14. A method for forming an ablation pattern to electrically isolate a vessel having an ostium from a cardiac chamber of a patient for treatment of a cardiac arrhythmia, the treatment comprising:

providing a catheter assembly including a catheter body defining a longitudinal axis and having a proximal portion and a distal portion, a wire basket connected to an exterior of the catheter body along the distal portion thereof, and a plurality of electrodes maintained by a plurality of elongated members of the wire basket, the wire basket being selectively transitionable between a retracted position and an expanded position, wherein in the retracted position and in the expanded position the plurality of electrodes are substantially equally spaced from the longitudinal axis of the catheter body by a first common spacing and a second common spacing, respectively, and wherein the first common spacing is less than the second common spacing and the plurality of elongated members are substantially aligned with the longitudinal axis of the catheter body;

guiding the distal portion into the chamber with the wire basket in the retracted position;

transitioning the wire basket to the expanded position such that the electrodes are positioned to define an ablation loop;

aligning the longitudinal axis with the vessel ostium;

advancing the distal portion such that the ablation loop contacts the chamber wall about the vessel ostium; and

energizing one or more of the electrodes to ablate a lesion pattern on the chamber wall about at least a portion of the vessel ostium to electrically isolate the vessel from the chamber.

15. The method of claim 14, wherein the chamber is a left atrium and the vessel is a pulmonary vein.

16. The method of claim 14, wherein the chamber is a right atrium and the vessel is a coronary sinus.

17. The method of claim 14, wherein transitioning the wire basket includes positioning the electrodes to define the ablation loop substantially transverse to the longitudinal axis.

18. The method of claim 17, wherein the ablation loop defines a central axis, and further wherein advancing the distal portion includes directing the distal portion in a direction parallel with the central axis.

19. The method of claim 14, wherein transitioning the wire basket includes forming the ablation loop to a size larger than a size of the vessel ostium.

20. The method of claim 14, wherein the wire basket includes proximal and distal collars connected to the catheter body, and further wherein transitioning the wire basket to the expanded position includes:

sliding at least one of the proximal and distal collars relative to an other of the proximal and distal collars.

21. The method of claim 20, wherein the proximal collar is slidable relative to the distal collar.

22. The method of claim 14, wherein the catheter assembly further includes a tip extending distal the wire basket, the method further including:

locating the vessel with the tip.

23. The method of claim 22, wherein the tip further includes a centering device, the method further comprising:

centering the ablation loop about the vessel ostium via the centering device.

24. The method of claim 22, wherein the tip further includes at least one mapping electrode distal the wire basket, the method further including:

mapping tissue of the vessel with the mapping electrode.

25. A method for forming an ablation pattern to electrically isolate a vessel having an ostium from a chamber formed within a patient for treatment of cardiac arrhythmia, the treatment comprising:

providing a catheter assembly including a catheter body defining a longitudinal axis and having a proximal portion and a distal portion, a wire basket connected to an exterior of a catheter body along the distal portion thereof, and a plurality of electrodes maintained by the wire basket, the wire basket being selectively transitionable between a retracted position and an expanded position;

guiding the distal portion into the chamber with the wire basket in the retracted position;

transitioning the wire basket to the expanded position such that the electrodes are positioned to define an ablation loop;

aligning the longitudinal axis with the vessel ostium;

advancing the distal portion such that the ablation loop contacts the chamber wall about the vessel ostium;

energizing one or more of the electrodes to ablate a lesion pattern on the chamber wall about at least a portion of the vessel ostium to electrically isolate the vessel from the chamber wherein the wire basket is comprised of a plurality of tubular wire struts fluidly connected to a cooling source, and further comprising the step of;

initiating fluid flow from the cooling source to the tubular wire struts following the step of energizing one or more of the electrodes.

26. The method of claim 25, wherein the catheter assembly further includes at least one temperature sensing element coupled to a portion of the wire basket, the method further comprising:

sensing a temperature at the chamber wall with the at feast one temperature sensing element following the step of energizing one or more of the electrodes.