Fluid cooled and perfused tip for a catheter

• US 6,017,338 A
• Filed: 06/30/1995
• Issued: 01/25/2000
• Est. Priority Date: 12/21/1993
• Status: Expired due to Term

• Current Assignee: Cordis Webster, Inc.
• Original Assignee: Angeion Corporation (Niterra Co., Ltd.)
• Inventors: Savage, Steven D., Saul, Jerome Philip, Brucker, Gregory G.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US08/496,947
• Time in Patent Office: 1,670 Days
• Field of Search: 606/41, 606/49, 607/122, 607/99, 607/105, 607/113, 128/642, 600/374
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• 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 2017/00084 Temperature
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00065 porous
• CPC Class Codes: A61B 2018/00357 Endocardium
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00982 combined with or comprising means for visual or photographic inspections inside the body, e.g. endoscopes
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2218/002 Irrigation
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61M 1/85 with gas or fluid supply means, e.g. for supplying rinsing fluids or anticoagulants for negative pressure wound therapy A61M1/92, A61M1/94; combined with tracheal tubes A61M16/0463; dental instruments with combined rinsing and aspirating A61C17/0208
• CPC Class Codes: A61M 2025/0073 Tip designed for influencing the flow or the flow velocity of the fluid, e.g. inserts for twisted or vortex flow general flow characteristics A61M2206/10
• CPC Class Codes: A61M 25/0068 Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure
• CPC Class Codes: A61M 25/0069 : Tip not integral with tube
• CPC Class Codes: A61M 25/0082 : Catheter tip comprising a tool

Abstract

The invention relates to an ablation catheter which controls the temperature and reduces the coagulation of biological fluids on a tip of a catheter, prevents the impedance rise of tissue in contact with the catheter tip, and maximizes the potential energy transfer to the tissue, thereby allowing an increase in the lesion size produced by the ablation. The ablation catheter includes a catheter body. The ablation catheter also includes a tip for monitoring electrical potentials, and applying electrical energy to a biological tissue. A fluid source is positioned at one end of the catheter for supplying a fluid flow through the catheter to the tip means. Passages are positioned within the tip in a variety of manners for directing the fluid flow through the tip means to the exterior surface of the tip to control the temperature and form a protective fluid layer around the tip. Monitoring structure is also positioned within the tip structure for measurement of the electrical potentials in a biological tissue. Ablation structure is also positioned within the tip for application of ablative energy to the biological tissue.

Claims

1. An ablation catheter that reduces coagulation of biological materials on a tip of the catheter by precluding ablation-inhibiting impedance rise of biological tissue adjacent the tip, the ablation catheter comprising:

a tip positioned at a distal end of the catheter to monitor electrical potentials and to apply ablation energy to a biological tissue, the tip having an exterior surface;

a fluid source positioned to supply a fluid flow through the catheter to the tip; and

structure defining a plurality of passages comprising interconnected interstitial spaces within the tip to direct fluid flow through the tip toward the exterior surface of the tip and to preclude ablation-inhibiting impedance rise of biological tissue adjacent the tip.

2. The ablation catheter of claim 1, further comprising ablation means at the tip for applying the ablation energy to the biological tissue.

3. The ablation catheter of claim 1, further comprising monitoring means at the tip for measuring electrical potentials within the biological tissue.

4. The ablation catheter of claim 1, wherein the structure defining the plurality of passages provides a fluid protective layer to minimize contact of the tip with biological materials.

5. The ablation catheter of claim 1, wherein the tip applies at least 100 W of ablation energy to the tissue while the structure defining a plurality of passages directs fluid flow toward the exterior surface at a rate of no more than 15 ml/min.

6. A catheter tip for signal measurement and monitoring, the catheter tip comprising:

an exterior surface;

means for providing fluid communication and commensurate flow of fluid from inside the tip to portions of the exterior surface of the tip through a plurality of randomly formed passages that direct the fluid flow from inside the tip over the exterior surface of tip; and

monitoring means within the tip for measurement of electrical potentials in a biological tissue.

7. The catheter tip of claim 6, wherein the means for providing fluid communication and flow provides a fluid protective layer at the exterior surface of the tip to minimize contact of the tip with biological materials.

8. The catheter tip of claim 7, wherein the fluid protective layer is a continuous fluid protective layer surrounding the tip.

9. The catheter tip of claim 8, wherein the fluid protective layer covers the entire exterior surface of the tip.

10. The catheter tip of claim 6, wherein the means for providing fluid communication and flow cools the tip to cool biological tissue adjacent the tip.

11. The catheter tip of claim 6, wherein the means for providing fluid communication and flow comprises structure defining a plurality of randomly disposed interstitial spaces.

12. An ablation catheter for delivering ablation energy to biological tissue, the ablation catheter comprising:

a tip disposed at a distal end of the ablation catheter to deliver at least 70 W of ablation energy to the tissue, the tip having an exterior;

a fluid source disposed at a proximal end of the ablation catheter;

an internal lumen extending through the catheter to provide fluid communication between the fluid source and the tip; and

path structure within the tip to direct fluid flow from the internal lumen toward the exterior of the tip at a flow rate of no more than 10 ml/min for 70 W of ablation energy, the catheter precluding ablation-inhibiting impedance rise.

13. The ablation catheter of claim 12, wherein the path structure directs fluid flow evenly over the exterior of the tip.

14. The ablation catheter of claim 13, wherein the path structure directs the fluid flow to form a protective layer over the exterior of the tip.

15. The ablation catheter of claim 14, wherein the protective fluid layer is a continuous layer.

16. The ablation catheter of claim 14, wherein the protective fluid layer surrounds the tip.

17. The ablation catheter of claim 12, wherein fluid flow through the path structure cools the tip.

18. The ablation structure of claim 12, wherein the path structure provides a specific flow of at least 0.29 ml/mm² /min. for a 10 ml/min. flow rate and at least 70 W of delivered ablation energy.

19. An ablation catheter for application of energy to biological tissue, the ablation catheter comprising:

a proximal end, a distal end and at least one lumen;

a tip at the distal end of the catheter, the tip including at least one electrode through which ablative energy is applied to the biological tissue, the electrode having an external surface;

a plurality of fluid paths disposed through the electrode, the fluid paths being generally between 5 and 20 microns in diameter and being constructed to direct fluid from the lumen through the electrode to the external surface of the electrode to form a protective layer of fluid around the electrode; and

a fluid source for directing fluid through the lumen and the plurality of fluid paths to the external surface of the electrode.

20. The ablation catheter of claim 19, wherein the electrode comprises a ring electrode.

21. The catheter of claim 19, wherein the electrode comprises a microporous structure.