Thermorecanalization catheter and method for use

• US 4,654,024 A
• Filed: 09/04/1985
• Issued: 03/31/1987
• Est. Priority Date: 09/04/1985
• Status: Expired due to Term

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Crittenden, James F., Weitzner, Barry D.
• Primary Examiner(s): Pellegrino, Stephen C.
• Application Number:
  US06/772,364
• Time in Patent Office: 573 Days
• Field of Search: 604/114, 604/113, 604/20, 604/21, 604/49, 604/53, 128/303.12, 128/303.1, 128/395-398, 219/121 LS
• US Class Current: 606/28
• CPC Class Codes: A61B 18/082 Probes or electrodes therefor
• CPC Class Codes: A61B 18/28 for heating a thermal probe or absorber
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00092 using thermocouples
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61M 3/0279 Cannula; Nozzles; Tips; their connection means

Abstract

A catheter with a heater mounted on its distal end is used to melt atherosclerotic plaque to clear an obstruction within an artery. The catheter heater is a tapered cone that emits heat from its outer, leading edges. Several embodiments are disclosed in which the power for the heater is generated by electrical resistance heating or by laser energy absorption. In the disclosed method of use, the guidewire is inserted into the lumen of the catheter so that the distal tip of the guidewire extends a few centimeters beyond the heater tip. The catheter is directed into the proper coronary branch by means of the guidewire and the wire is advanced until it meets the obstruction. If the wire can be advanced through the obstruction, the catheter is advanced over the wire until the heater contacts the plaque. The heater is then operated and the catheter is advanced as the plaque melts. If the guidewire cannot be pushed through the obstruction, the guidewire and catheter are advanced together until the obstruction is breached and the guidewire can be extended down the artery. Once a suitable channel has been opened, the catheter is removed and a conventional balloon dilatation catheter is slid over the guidewire to enlarge the stenosis in a conventional manner.

Claims

1. A catheter for breaching a restriction in an artery caused by atherosclerotic plaque, said catheter comprising,

a catheter body having a proximal end and a distal end and a lumen passing through the center thereof and extending along the length thereof for accepting a guidewire,

a heater attached to said distal end, said heater comprising,

a cone having a base attached to said distal end, said cone having a hole therethrough extending perpendicularly to said base through the center of said cone to allow passage of a guidewire,

means for heating the sloping surface of said cone to a temperature sufficient to cause said plaque to melt and

means responsive to the temperature of said sloping surface for returning a signal having a value related to the temperature of said sloping surface to the proximal end of said catheter body.

2. A catheter for breaching a restriction in an artery according to claim 1 further comprising a thermally-conductive, electrically-insulating coating on the surface of said cone.

3. A catheter for breaching a restriction in an artery according to claim 1 wherein said heating means comprises a length of electrical resistance wire wound on a thermally-insulating and electrically-insulating core.

4. A catheter for breaching a restriction in an artery according to claim 1 wherein said heating means comprises an etched foil heating element bonded to a thermally-insulating and electrically-insulating cone.

5. A catheter for breaching a restriction in an artery according to claim 1 wherein said cone is comprised of electrically-resistive epoxy and said heating means comprises means for connecting said cone to an electrical power source.

6. A catheter for breaching a restriction in an artery according to claim 1 wherein said cone is comprised of thermally-conductive material and said heating means comprises means for causing the output from a laser to impinge on said cone.

7. A catheter for breaching a restriction in an artery according to claim 1 wherein said heating means further comprises means for providing power to said cone to heat said cone, means responsive to the temperature of said cone for generating a temperature signal and means responsive to said temperature signal for controlling the amount of power provided to said cone.

8. A catheter for breaching a restriction in an artery according to claim 7 wherein said means for generating said temperature signal comprises a thermocouple.

9. A catheter for breaching a restriction in an artery according to claim 7 wherein said means for generating said temperature signal comprises a resistance temperature detector.

10. A catheter for breaching a restriction in an artery caused by atherosclerotic plaque, said catheter comprising,

a catheter body having a proximal end and a distal end and having a first, a second and a third lumen passing through, said first lumen passing through the center of said catheter and extending along the length thereof for accepting a guidewire,

a heater attached to said distal end, said heater comprising,

a cone having a base attached to said distal end, said cone having a hole therethrough extending perpendicularly to said base through the center of said cone to allow passage of a guidewire, and

a heater located in said cone for heating the sloping surface of said cone to a temperature sufficient to cause said plaque to melt,

means passing through said second lumen for providing power to said heater,

means responsive to the temperature of said cone for generating a temperature signal, and

means responsive to said temperature signal for sending a feedback signal through said third lumen to the proximal end of said catheter.

11. A catheter for breaching a restriction in an artery according to claim 10 further comprising a thermally-conductive, electrically-insulating coating on the surface of said cone.

12. A catheter for breaching a restriction in an artery according to claim 10 wherein said heater comprises a length of electrical resistance wire wound on a thermally-insulating and electrically-insulating core.

13. A catheter for breaching a restriction in an artery according to claim 10 wherein said heater comprises an etched foil heating element bonded to a thermally-insulating and electrically-insulating cone.

14. A catheter for breaching a restriction in an artery according to claim 10 wherein said cone is comprised of electrically-resistive epoxy and said heater comprises means for connecting said cone to an electrical power source.

15. A catheter for breaching a restriction in an artery caused by atherosclerotic plaque, said catheter comprising,

a catheter body having a proximal end and a distal end and having a first, a second and a third lumen passing through, said first lumen passing through the center of said catheter and extending along the length thereof for accepting a guidewire,

a heater attached to said distal end, said heater comprising,

a cone having a base attached to said distal end,

said cone having a hole therethrough extending perpendicularly to said base through the center of said cone to allow passage of a guidewire and said cone being comprised of thermally-conductive material,

a heater located in said cone for heating the sloping surface of said cone to a temperature sufficient to cause said plaque to melt, said heater comprising means for causing the output from a laser to impinge on said cone,

means passing through said second lumen for providing power to said heater,

means responsive to the temperature of said cone for generating a temperature signal, and

means responsive to said temperature signal for sending a feedback signal through said third lumen to the proximal end of said catheter.

16. A catheter for breaching a restriction in an artery according to claim 15 wherein the output of a laser is conveyed from the proximal end of said catheter to the distal end of said catheter by means of an optical fiber passing through said second lumen.

17. A method for breaching a restriction in an artery caused by atherosclerotic plaque by means of a catheter having a heating tip and a lumen therethrough for accepting a guidewire, said method comprising the steps of:

A. positioning said catheter over said guidewire so that the tip of the guidewire extends a few centimeters beyond the tip of said catheter,

B. inserting the catheter and guidewire into a patient'"'"'s artery by means of a guiding catheter,

C. manipulating said guidewire to direct the heater catheter into the proper branch of the vasculature,

D. when said guidewire reaches the restricted area, pushing said guidewire down the artery past said restriction,

E. advancing said catheter over said guidewire until said heating tip contacts said restriction,

F. operating said heating tip,

G. advancing said catheter as the plaque softens and melts until said restriction is breached,

H. removing said catheter by sliding it over said guidewire leaving said guidewire in place, and

I. inserting a balloon dilatation catheter along said guidewire to enlarge the stenosis and complete the repair procedure.