Ablation catheter with fluid distribution structures

• US 20060287650A1
• Filed: 06/21/2005
• Published: 12/21/2006
• Est. Priority Date: 06/21/2005
• Status: Active Grant

• Current Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Original Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Inventors: Paul, Saurav, Cao, Hong, Belhe, Kedar R., Thao, Chou, Stangenes, Todd
• Granted Patent: US 7,819,868 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 2018/00375 Ostium, e.g. ostium of pulmonary vein or artery
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes

Abstract

An ablation catheter has improved fluid distribution structures. An ablation section at a distal end of the catheter is designed to provide a more uniform fluid flow emanating from the catheter. By creating a uniform fluid flow, a more uniform tissue lesion results and the possibility of charring the tissue is reduced. A combination of mesh material layers, porous materials, and dispersion channels or openings are used to achieve the uniform flow. The amount of fluid used as a virtual electrode to ablate the tissue is greatly reduced with the present invention. Further, the catheter may be used to create a single, uniform linear lesion by successive application of energy to adjacent portions of the ablation section, thus reducing the power required to create the desired lesion.

Claims

1. A catheter with a distal ablation electrode section, the catheter comprising:

a proximal section;

an ablation section at a distal end of the catheter;

a catheter wall defining at least one fluid lumen extending from the proximal section to the ablation section;

an electrode lead positioned within the at least one fluid lumen extending within the ablation section;

at least one dispersion opening within the catheter wall in the ablation section oriented longitudinally along a length of the ablation section, wherein the at least one dispersion opening is in fluid communication with the at least one fluid lumen; and

a length of mesh material generally coextensive with and positioned adjacent to the at least one dispersion opening on the opposing side of the at least one dispersion opening from the at least one fluid lumen.

2. The catheter of claim 1 further comprising:

a retention layer about the distal end of the catheter;

wherein the retention layer defines an elongate aperture generally coextensive with the dispersion opening; and

wherein a perimeter edge of the mesh material is retained between the retention layer adjacent the elongate aperture and an outer surface of the catheter adjacent the at least one dispersion opening.

3. The catheter of claim 2, wherein the retention layer is an insulating shrink wrap tube.

4. The catheter of claim 1, wherein the mesh material is a conductive material.

5. The catheter of claim 4, wherein the mesh material is selected from a group of materials consisting of:

platinum, platinum/iridium, gold, stainless steel, and carbon fiber.

6. The catheter of claim 4, wherein the electrode lead is coupled with the mesh material.

7. The catheter of claim 1 further comprising a porous material interposed both between the mesh material and the at least one dispersion opening and between the mesh material and the outer surface of the catheter adjacent the at least one dispersion opening.

8. The catheter of claim 7, wherein the porous material is selected from a group of materials consisting of:

a micro-porous material, a macro-porous material, polyvinyl alcohol (PVA), polytetrafluroethylene (PTFE), expanded polytetrafluroethylene (ePTFE), porous polyethylene, porous polypropylene, and collagen.

9. The catheter of claim 2 further comprising a porous material interposed both between the mesh material and the at least one dispersion opening and between the mesh material and the outer surface of the catheter adjacent the at least one dispersion opening.

10. The catheter of claim 9, wherein the porous material is selected from a group of materials consisting of:

a micro-porous material, a macro-porous material, polyvinyl alcohol (PVA), polytetrafluroethylene (PTFE), expanded polytetrafluroethylene (ePTFE), porous polyethylene, porous polypropylene, and collagen.

11. The catheter of claim 1, wherein the at least one dispersion opening comprises a plurality of portholes arranged linearly and oriented longitudinally along the length of the ablation section of the catheter.

12. The catheter of claim 1, wherein the dispersion opening comprises at least one linear slot oriented longitudinally along a length of the ablation section of the catheter.

13. The catheter of claim 1 further comprising a porous material interposed between at least a portion of the mesh material and the dispersion opening.

14. The catheter of claim 13, wherein the mesh material comprises a conductive coating on a surface of the porous material.

15. The catheter of claim 13, wherein the mesh material is formed in the shape of a tube and the porous material fills the tube.

16. The catheter of claim 13, wherein the mesh material comprises a first mesh section and a second mesh section and the first mesh section is electrically insulated from the second mesh section.

17. The catheter of claim 13, further comprising

an irrigation cavity positioned within the ablation section of the catheter;

an elongate opening in an outside surface of the catheter wall in fluid communication with the irrigation cavity;

wherein the at least one dispersion opening provides fluid communication between the at least one fluid lumen and the irrigation cavity; and

wherein the porous material and the mesh material are positioned within the irrigation cavity.

18. The catheter of claim 17, wherein

the at least one fluid lumen comprises a first fluid lumen and a second fluid lumen;

the at least one dispersion opening comprises a first dispersion opening and a second dispersion opening;

the first fluid lumen is in fluid communication with the first dispersion opening and the first dispersion opening is in fluid communication with the irrigation cavity; and

the second fluid lumen is in fluid communication with the second dispersion opening and the second dispersion opening is in fluid communication with the irrigation cavity.

19. The catheter of claim 18, wherein

the first dispersion opening supplies fluid from the first fluid lumen to a proximal portion of the irrigation cavity;

and

the second dispersion opening supplies fluid from the first fluid lumen to a distal portion of the irrigation cavity.

20. The catheter of claim 18, wherein

the first dispersion opening comprises a first plurality of portholes between the first fluid lumen and the irrigation cavity;

and

the second dispersion opening comprises a second plurality of portholes between the second fluid lumen and the irrigation cavity.

21. The catheter of claim 17, wherein the mesh material is formed in the shape of a tube and the porous material fills the tube.

22. The catheter of claim 17, wherein the elongate opening in the catheter wall is subdivided into a plurality of openings separated by at least one bridge member connecting a top edge of the elongate opening to a bottom edge of the elongate opening.

23. The catheter of claim 22, wherein the mesh material is formed in the shape of a tube and the porous material fills the tube.

24. The catheter of claim 23, wherein

the mesh material further comprises a first mesh section and a second mesh section;

the first mesh section is electrically insulated from the second mesh section.

25. The catheter of claim 23, wherein

the porous material further comprises a first porous section and a second porous section;

and

the first porous section is fluidly isolated from the second porous section.

26. The catheter of claim 13, wherein

the mesh material is formed in the shape of a first tube with a first outer diameter and a first inner diameter;

the porous material is in the shape of a second tube with a second outer diameter and a second inner diameter;

the first outer diameter is sized to fit snugly within an inner diameter of the fluid lumen in the ablation section; and

the second outer diameter is sized to fit snugly within the first inner diameter of the first tube.

27. A catheter with a distal ablation electrode tip comprising:

a proximal section;

an ablation section at a distal end of the catheter;

a catheter wall defining at least one fluid lumen extending from the proximal section to the ablation section;

at least one dispersion opening within the catheter wall in the ablation section oriented longitudinally along a length of the ablation section, wherein

the at least one dispersion opening is in fluid communication with the at least one fluid lumen;

an irrigation cavity positioned within the ablation section of the catheter;

an elongate opening in an outside surface of the catheter wall in fluid communication with the irrigation cavity;

wherein

the at least one dispersion opening provides fluid communication between the at least one fluid lumen and the irrigation cavity;

a tube-shaped, conductive mesh material generally coextensive with and positioned within the irrigation cavity;

a porous material positioned within and filling a lumen of the tube-shaped, conductive mesh material; and

an electrode lead coupled with the tube-shaped, conductive mesh material.

28. The catheter of claim 27, wherein

the at least one fluid lumen comprises a first fluid lumen and a second fluid lumen;

the at least one dispersion opening comprises a first dispersion opening and a second dispersion opening;

each of the first dispersion opening and the second dispersion opening is a linear slot oriented longitudinally along a length of the ablation section of the catheter;

the first fluid lumen is in fluid communication with the first dispersion opening and the first dispersion opening is in fluid communication with the irrigation cavity; and

the second fluid lumen is in fluid communication with the second dispersion opening and the second dispersion opening is in fluid communication with the irrigation cavity.

29. The catheter of claim 27, wherein

the at least one fluid lumen comprises a first fluid lumen and a second fluid lumen;

the at least one dispersion opening comprises a first dispersion opening and a second dispersion opening;

each of the first dispersion opening and the second dispersion opening comprises a plurality of portholes arranged linearly and oriented longitudinally along the length of the ablation section of the catheter;

the first fluid lumen is in fluid communication with the first dispersion opening and the first dispersion opening is in fluid communication with the irrigation cavity; and

the second fluid lumen is in fluid communication with the second dispersion opening and the second dispersion opening is in fluid communication with the irrigation cavity.

30. A catheter with a distal ablation electrode tip comprising:

a proximal section;

an ablation section at a distal end of the catheter;

a catheter wall defining at least one fluid lumen extending from the proximal section to the ablation section;

an irrigation cavity formed by the distal end of the fluid lumen within the ablation section of the catheter;

a tube-shaped, conductive mesh material generally coextensive with and positioned within the irrigation cavity;

wherein

the tube-shaped, conductive mesh material has a first outer diameter and a first inner diameter; and

the first outer diameter is sized to fit snugly within an inner diameter of the irrigation cavity;

a tube-shaped porous material with a second outer diameter and a second inner diameter;

wherein

the second outer diameter is sized to fit snugly within the first inner diameter of the first tube;

an elongate opening in an outside surface of the catheter wall in fluid communication with the irrigation cavity; and

an electrode lead coupled with the tube-shaped, conductive mesh material.

31. A catheter with a distal ablation electrode tip comprising:

a proximal section;

an ablation section at a distal end of the catheter;

a catheter wall defining a first fluid lumen extending from the proximal section to the ablation section and a second fluid lumen extending from the proximal section to the ablation section;

an irrigation cavity positioned within the ablation section of the catheter;

an insulating plug positioned within the irrigation cavity and separating the irrigation cavity into a proximal portion and a distal portion;

a first dispersion opening within the catheter wall in the ablation section oriented longitudinally along a length of the ablation section, wherein

the first dispersion opening is in fluid communication with both the first fluid lumen and the proximal portion of the irrigation cavity;

a second dispersion opening within the catheter wall in the ablation section oriented longitudinally along a length of the ablation section, wherein

the second dispersion opening is in fluid communication with both the second fluid lumen and the distal portion of the irrigation cavity;

an elongate opening in an outside surface of the catheter wall in fluid communication with the irrigation cavity, wherein

the elongate opening is subdivided into a proximal opening and a distal opening separated by a bridge member;

the proximal opening is generally coextensive with the proximal portion of the irrigation cavity;

the distal opening is generally coextensive with the distal portion of the irrigation cavity; and

the bridge member connects a top edge of the elongate opening to a bottom edge of the elongate opening;

a first tube-shaped, conductive mesh section generally coextensive with and positioned within the proximal portion of the irrigation cavity;

a second tube-shaped, conductive mesh section generally coextensive with and positioned within the distal portion of the irrigation cavity, wherein

the first tube-shaped, conductive mesh section is electrically insulated from the second tube-shaped, conductive mesh section by the insulating plug;

a first porous material section positioned within and filling the first tube-shaped, conductive mesh section;

a second porous material section positioned within and filling the second tube-shaped, conductive mesh section, wherein

the first porous material section is fluidly isolated from the second porous material section by the insulating plug; and

an electrode lead coupled with the tube-shaped, conductive mesh material.

32. A method of creating a uniform flow of a fluid emanating from an ablation section at a distal end of a catheter, the method comprising

flowing a conductive fluid through a lumen in the catheter, wherein a first pressure drop across the conductive fluid in the lumen is created between a proximal end of the catheter and the ablation section;

flowing the conductive fluid from the lumen through a porous material positioned in the ablation section;

wherein a second pressure drop is created between a first surface of the porous material and a second surface of the porous material; and

wherein the second pressure drop through the porous material is higher than the first pressure drop; and

flowing the conductive fluid through a mesh electrode adjacent the porous material.

33. The method of claim 32 further comprising

energizing the mesh electrode;

and

transferring energy from the mesh electrode to the conductive fluid.

34. The method of claim 32 further comprising maintaining a constant voltage across the mesh electrode.