Catheters for clot removal

• US 20030171741A1
• Filed: 11/14/2002
• Published: 09/11/2003
• Est. Priority Date: 11/14/2001
• Status: Abandoned Application

• Current Assignee: Latis, Inc.
• Original Assignee: Latis, Inc.
• Inventors: Porter, Christopher H., Ziebol, Robert
• Application Number:
  US10/295,003
• Publication Number:
  US 20030171741A1
• Time in Patent Office: Days
• US Class Current: 606/7
• CPC Class Codes: A61B 18/245 for removing obstructions in blood vessels or calculi
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2018/2272 with reflective or refractive surfaces for deflecting the beam A61B2018/2261, A61B2018/2266 take precedence

Abstract

Improved catheters for clot removal. A catheter-containing light guide may be passed through a clot. Light may emanating from the light guide as the light guide is passed forward through the clot and/or is drawn back through the clot in order to ablate the clot. In one set of embodiments, the invention provides for methods and systems for delivering the light guide through the clot and for drawing it back through the clot to irradiate and/or ablate the clot. The invention provides, in another set of embodiments, methods and systems to deliver the light energy or radiation to the clot to perform ablation, for example during a single pass. The invention also provides, in yet another set of embodiments, methods and systems to increase the efficiency of the ablation, for example, by increasing the spot size. In still another set of embodiments, the invention provides methods and systems to remove blood from the area between the point on the light guide where the light exits and the portion of the clot to be ablated (“clearing the field”). These and other embodiments of the invention may be combined in various ways to provide a catheter system optimally designed for the particular application.

Claims

1. A system for ablating a clot by passing a light guide through the clot and then drawing the light guide back through the clot, light energy being applied to the light guide when it is passing in at least one direction through the clot, wherein the light guide is at least one of forward firing and side firing.

2. A system as claimed in claim 1, wherein the light guide is side firing.

3. A system as claimed in claim 1, wherein a guide wire is affixed to the end of the light guide to facilitate passing the light guide through the clot.

4. A system as claimed in claim 1, wherein the light guide is mounted in a catheter which is also passed through the clot but remains stationary in the clot while the light guide is moved to ablate the clot, the catheter being optically transparent.

5. A system as claimed in claim 4, including passing a flush fluid through the catheter, the catheter having openings therein adjacent portions of the light guide from which light is to emanate.

6. A system as claimed in claim 4, wherein said light guide is formed of at least three optical fibers angled to deliver light in different directions.

7. A system as claimed in claim 6, wherein the distal end of said fibers are covered with an optically transparent cap sealed to the fibers to form an air gap between the distal end of the fibers and the cap.

8. A system as claimed in claim 4, including a mechanism for guiding the position of the light guide to a desired rotational position.

9. A system as claimed in claim 4, wherein said light guide is formed of a plurality of fibers angled to all direct light in the same direction, whereby the energy delivered by the light guide in the area over which the energy may be delivered is increased.

10. A system as claimed in claim 1, wherein said light guide is forward firing, and including a catheter through which said light guide passes and which is pulled back through the clot with the catheter, the catheter being guided through the clot by one of a guide wire fixed to the distal end of the catheter, and a guide wire passing through a separate lumen of the catheter.

11. A system as claimed in claim 1, wherein said light guide is forward firing, including a mechanism for moving the distal end of the catheter relative to the clot to facilitate clot ablation.

12. A system as claimed in claim 11, wherein said mechanism for moving the distal end of the catheter includes a mechanism for bending the distal end of the catheter to change the direction in which the light beam is directed.

13. A system as claimed in claim 11, wherein said mechanism for controlling the direction of the distal end of the catheter includes a mechanism for providing lateral movement of the catheter in the vessel to facilitate ablation of the clot.

14. A system as claimed in claim 13, wherein said mechanism for affording lateral movement of the distal end of the catheter includes one of an inflatable balloon mechanism, an extending wire structure, and means for extending fluid jets from the catheter, each of which interacts with the walls of the vessel to selectively position the catheter therein.

15. A system as claimed in claim 13, wherein said catheter is eccentrically mounted in the vessel and is rotatable to translate the distal end of the catheter in the vessel.

16. A system as claimed in claim 1, wherein said light guide is front firing and including a lens at the distal end of one of said catheter and a fiber.

17. A system as claimed in claim 1, wherein said light guide is front firing and including a target for enhancing the ablation by light energy.

18. A system as claimed in claim 17, wherein said target includes a light absorbing material diffused and absorbed into the clot prior to irradiation by light from said light guide

19. A system as claimed in claim 17, wherein said target includes a light absorbing material positioned in front of said clot which is heated by the light from said light guide to cause a shock wave which effects ablation.

20. A system as claimed in claim 1, wherein said system is used to ablate clots in brain vessels.

21. A system as claimed in claim 1, wherein said light guide is forward firing, and including a guide wire which facilitates movement of the light guide and/or a catheter mounting the light guide in at least one direction through the clot and which remains in place when light energy is applied to the light guide, the guide wire having at least a distal end with a low refractive index, at least at the wavelength of the light energy.

22. A guide wire for use in an optical ablation system where light energy used for ablation may impinge on the guide wire, the guide wire being formed so that at least the distal end thereof has a low refractive index at least at the wavelength of the light energy.

23. A guide wire as claimed in claim 22, wherein said guide wire is formed of a core of guide wire material having at least the distal end thereof coated with a material having said low refractive index.