Ablation device for lead extraction and methods thereof

• US 6,033,402 A
• Filed: 09/28/1998
• Issued: 03/07/2000
• Est. Priority Date: 09/28/1998
• Status: Expired due to Term

• Current Assignee: Irvine Biomedical, Inc. (Abbott Laboratories)
• Original Assignee: Irvine Biomedical, Inc. (Abbott Laboratories)
• Inventors: Tu, Hosheng, Hata, Cary
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US09/161,890
• Time in Patent Office: 526 Days
• Field of Search: 606/41, 606/45, 606/48, 606/108, 607/122
• 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: A61N 2001/0578 having means for removal or extraction

Abstract

An improved lead extraction system using a retractable inner catheter having an electrode means comprising memory-shaped Nitinol sheet members and a RF current generator to raise the temperature to above the transitional shape-change temperature of the Nitinol with a sharp cutting edge. The lead extraction system is useful for the extraction and the removal of unwanted lead by a minimal invasive procedure. In another embodiment, fluid infusion and irrigation means at its distal tip section and an electrode means for loosening the target scar tissue by applying radiofrequency energy and cooled fluid to the said electrode and its contacted tissue.

Claims

1. A lead extraction system comprising:

a guiding shaft having a shaft distal end, a shaft proximal end, and at least one lumen extending between the shaft distal end and the shaft proximal end;

a handle attached to the shaft proximal end of the guiding shaft, wherein the handle has a cavity;

a retractable inner catheter located inside the at least one lumen of the guiding shaft, wherein the retractable inner catheter has a distal end and a proximal end;

an electrode means having a plurality of sheet members secured to the distal end of the retractable inner catheter, each of the plurality sheet members of the electrode means having a proximal end and a sharp-edge distal end, wherein the proximal ends of the plurality of sheet members are joined at the distal end of the retractable inner catheter, and wherein an electrical conductor is attached to the electrode means; and

a deployment controller mounted on the handle and secured to the proximal end of the retractable inner catheter, the deployment controller having a deployed state for the retractable inner catheter to deploy outside of the shaft distal end of the guiding shaft, and the deployment controller having a non-deployed state for the retractable inner catheter to be retracted within the at least one lumen of the guiding shaft.

2. The lead extraction system of claim 1 further comprising a RF current generator, wherein the RF current is delivered to the electrode means.

3. The lead extraction system as in claim 1, wherein the sheet members of the electrode means are made of a memory-shaped Nitinol, and wherein the Nitinol has a transitional shape-change temperature.

4. The lead extraction system of claim 1 further comprising a means for supplying fluid to the shaft distal end of the guiding shaft and diffused out of the shaft distal end of the guiding shaft.

5. The lead extraction system as in claim 4, wherein the fluid is selected from the group consisting of saline, heparin, antibiotics, anti-inflammatory agent, chemotherapy fluid, and therapeutics fluid.

6. The lead extraction system as in claim 3, wherein the transitional shape-change temperature for the memory-shaped Nitinol is about 50 degree Celsius.

7. The lead extraction system as in claim 6, wherein the memory-shaped Nitinol is activated by the RF current from a RF current generator.

8. The lead extraction system of claim 2 further comprising at least one temperature sensing means and a closed-loop temperature controller for the lead extraction system, wherein a temperature sensed by the temperature sensing means is relayed to the closed-loop temperature controller to effect the control of the RF current to the electrode means.

9. The lead extraction system of claim 4 further comprising a system for controlling the flow rate of the fluid through the electrode lumen of the guiding shaft.

10. The lead extraction system as in claim 2, wherein the RF current is within the range of 50 to 2,000 kHz.

11. A method for operating a lead extraction system to separate a scar tissue from the lead, the lead extraction system comprising a guiding shaft and a retractable inner catheter, wherein the retractable inner catheter has a distal end and a proximal end;

an electrode means having a plurality of sheet members secured to the distal end of the retractable inner catheter, each of the plurality sheet members of the electrode means having a proximal end and a sharp-edge distal end, wherein the proximal ends of the plurality sheet members are joined at the distal end of the retractable inner catheter, and wherein an electrical conductor is attached to the electrode means; and

a deployment controller mounted on the handle and secured to the proximal end of the retractable inner catheter, the deployment controller having a deployed state for the retractable inner catheter to deploy outside of the shaft distal end of the guiding shaft, the deployment controller having a non-deployed state for the retractable inner catheter to be retracted within one of the plurality of lumens of the guiding shaft; and

a RF current generator,

wherein the RF current is delivered to the electrode means;

the method comprising steps of;

(a) sliding the lead extraction system over an existing lead in a patient;

(b) intimately contacting the distal end of the catheter sheath with a scar tissue on the lead;

(c) deploying the retractable inner catheter;

(d) applying RF current to the electrode means;

(e) extracting the lead by pulling the system out of a patient.

12. The method for operating the lead extraction system as in claim 11 further comprising supplying a fluid to the guiding shaft.

13. The method for operating the lead extraction system of claim 11, wherein the sheet members of the electrode means are made of a memory-shaped Nitinol, and wherein the Nitinol has a transitional shape-change temperature.

14. The method for operating the lead extraction system of claim 12, wherein the fluid is selected from the group consisting of saline, heparin, antibiotics, anti-inflammatory agent, chemotherapy fluid, and therapeutics fluid.

15. The method for operating the lead extraction system as in claim 11 further comprising at least one temperature sensing means and a closed-loop temperature controller for the lead extraction system, wherein a temperature sensed by the temperature sensing means is relayed to the closed-loop temperature controller to effect the control of the RF current to the electrode means.

16. A method for operating a lead extraction system to separate a scar tissue from the lead, the lead extraction system comprising:

a guiding shaft having a shaft distal end, a shaft proximal end, and a plurality of lumens extending between the shaft distal end and the shaft proximal end;

a handle attached to the shaft proximal end of the guiding shaft, wherein the handle has a cavity;

a retractable inner catheter located inside one of the plurality of lumens of the guiding shaft, wherein the retractable inner catheter has a distal end and a proximal end;

an electrode means having a plurality of sheet members secured to the distal end of the retractable inner catheter, each of the plurality sheet members of the electrode means having a proximal end and a sharp-edge distal end, wherein the proximal ends of the plurality sheet members are joined at the distal end of the retractable inner catheter, and wherein an electrical conductor is attached to the electrode means;

a deployment controller mounted on the handle and secured to the proximal end of the retractable inner catheter, the deployment controller having a deployed state for the retractable inner catheter to deploy outside of the shaft distal end of the guiding shaft, and the deployment controller having a non-deployed state for the retractable inner catheter to be retracted within one of the plurality of lumens of the guiding shaft; and

a RF current generator, wherein the RF current is delivered to the electrode means;

the method comprising steps of;

(a) sliding the lead extraction system over an existing lead in a patient;

(b) intimately contacting the distal end of the catheter sheath with a scar tissue on the lead;

(c) deploying the retractable inner catheter;

(d) applying RF current to the electrode means;

(e) extracting the lead by pulling the system out of a patient.

17. The method for operating the lead extraction system as in claim 16, further comprising supplying a fluid to the guiding shaft.

18. The method for operating the lead extraction system of claim 17, wherein the fluid is selected from the group consisting of saline, heparin, antibiotics, anti-inflammatory agent, chemotherapy fluid, and therapeutics fluid.

19. The method for operating the lead extraction system of claim 16, wherein the sheet members of the electrode means are made of a memory-shaped Nitinol, and wherein the Nitinol has a transitional shape-change temperature.

20. The method for operating the lead extraction system as in claim 16 further comprising at least one temperature sensing means and a closed-loop temperature controller for the lead extraction system, wherein a temperature sensed by the temperature sensing means is relayed to the closed-loop temperature controller to effect the control of the RF current to the electrode means.