Method and apparatus for R-F ablation

• US 5,431,649 A
• Filed: 08/27/1993
• Issued: 07/11/1995
• Est. Priority Date: 08/27/1993
• Status: Expired due to Term

• Current Assignee: Reed A. Duthler
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hoey, Michael F., Mulier, Peter M. J.
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US08/113,441
• Time in Patent Office: 683 Days
• Field of Search: 606/32, 606/41, 606/45-49, 607/119, 607/120, 607/122, 607/126, 607/127, 607/130, 607/131, 128/642
• US Class Current: 606/41
• CPC Class Codes: A61B 10/02 Instruments for taking cell samples or for biopsy A61B10/0038 and A61B10/0045 take precedence; needle locating or guiding means A61B17/3403; samplers for enzymology or microbiology C12M1/26; sampling or preparing biological specimens G01N33/48
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1477 Needle-like probes
• 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 2017/00097 one of the thermometric elements being an electrode or the heating element
• CPC Class Codes: A61B 2017/00274 Prostate operation, e.g. prostatectomy, turp, bhp treatment
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2017/22077 with a part piercing the tissue A61B2017/22044 takes precedence
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00065 porous
• CPC Class Codes: A61B 2018/0022 Balloons
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00452 Skin
• CPC Class Codes: A61B 2018/00476 Hair follicles
• CPC Class Codes: A61B 2018/00547 Prostate
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/126 : bipolar
• CPC Class Codes: A61B 2018/1425 : Needle
• CPC Class Codes: A61B 2018/1435 : Spiral
• CPC Class Codes: A61B 2018/1472 : for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2090/064 : for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2090/3925 : ultrasonic
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61M 2025/0089 : Single injection needle protruding axially, i.e. along the longitudinal axis of the catheter, from the distal tip
• CPC Class Codes: A61M 2230/08 : Other bio-electrical signals
• CPC Class Codes: A61M 25/0084 : being one or more injection needles

Abstract

An ablation catheter and a method of performing cardiac ablation. The catheter is provided with a hollow, helical electrode, which is screwed into cardiac tissue at a desired ablation site and connected to a source of R-F electrical energy to ablate the tissue adjacent the electrode. Prior to ablation, a conductive fluid may be injected through the hollow needle, both to provide for cooling of the tissue adjacent the needle and to increase the conductivity of the tissue in the area of the electrode.

Claims

1. An ablation catheter system, comprising:

an elongated catheter body having a proximal end, a distal end and an internal longitudinal lumen;

an elongated electrical conductor, mounted within said catheter body;

a hollow helical conductive needle mounted to the proximal end of said catheter body and having an internal lumen coupled to the internal lumen of said catheter body, said hollow needle coupled to said electrical conductor;

fluid delivery means coupled to the internal lumen of said catheter body for delivering a conductive fluid to said internal lumen of said catheter body; and

a source of R-F electrical energy, coupled to said electrical conductor.

2. A catheter system according to claim 1 wherein said conductive fluid delivering means comprises means for delivering Ringer'"'"'s solution.

3. A catheter system according to claim 1 wherein said conductive fluid delivering means comprises a reservoir containing said conductive fluid and a means for controlling fluid flow.

4. A catheter system according to claim 1 wherein said catheter body comprises a torque transfer cable, extending longitudinally along said catheter body.

5. A catheter system according to claim 1 wherein said catheter comprises a conductive torque transfer cable, extending longitudinally along said catheter body, coupled to said hollow needle and to said source of R-F electrical energy.

6. A catheter system according to claim 1 wherein said catheter comprises a conductive tube, extending longitudinally along said catheter body, coupled to said hollow needle and to said source of R-F electrical energy.

7. A catheter system according to claim 1 wherein said catheter comprises a plastic tube, extending longitudinally along said catheter body, coupled to said hollow needle and to said fluid delivery means.

8. A method of catheter ablation, comprising:

advancing an elongated catheter having a proximal end, a distal end, an internal longitudinal lumen, an electrical conductor and a hollow helical conductive needle mounted to the proximal end of said catheter body, coupled to the internal lumen of said catheter and to said electrical conductor, to a desired site within a heart;

screwing said helical needle into heart tissue at said desired site;

delivering a conductive fluid through the internal lumen of said catheter to said helical needle;

coupling said electrical conductor to a source of R-F electrical energy; and

delivering R-F electrical energy to said helical needle.

9. A method according to claim 8 wherein said step of screwing said helical needle into heart tissue comprises rotating said catheter.

10. A method according to claim 8, further comprising the step of connecting said electrical conductor to ECG monitoring apparatus.

11. A method according to claim 8 wherein said catheter comprises a torque transfer cable, extending longitudinally along said catheter and coupled to said helical needle and wherein said step of screwing said helical needle into heart tissue comprises rotating said torque transfer cable.

12. A method according to claim 8 wherein said catheter comprises a plastic tube, extending longitudinally along said catheter body, coupled to said helical needle and further comprising the step of delivering said conductive fluid through said plastic tube prior to said step of screwing said needle into said heart tissue.

13. A method according to claim 8 wherein said step of delivering said conductive fluid comprises delivering Ringer'"'"'s solution.