Guide wire system for RF recanalization of vascular blockages

• US 20010012934A1
• Filed: 03/20/2001
• Published: 08/09/2001
• Est. Priority Date: 02/24/1999
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Fedie, Byron, Ren, Brooke Qin, Guo, Zihong, Chandrasekaran, Verivada
• Granted Patent: US 6,562,031 B2
• Time in Patent Office: Days
• 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: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2017/22094 for crossing total occlusions, i.e. piercing
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00261 arranged in a line
• CPC Class Codes: A61B 2018/00279 deployable
• CPC Class Codes: A61B 2018/00285 Balloons
• CPC Class Codes: A61B 2018/0041 Removal of thrombosis
• CPC Class Codes: A61B 2018/00422 Angioplasty
• CPC Class Codes: A61B 2018/00625 Vaporization
• CPC Class Codes: A61B 2018/1213 creating an arc
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/1435 Spiral
• CPC Class Codes: A61B 2018/144 Wire
• CPC Class Codes: A61M 2025/1047 having centering means, e.g. balloons having an appropriate shape
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00

Abstract

A system for recanalizing an occluded blood vessel including a centering catheter employed to center an ablative guide wire within the blood vessel as the guide wire traverses the occlusion. The centering catheter includes a catheter body with an operative lumen through which the ablative guide wire is slidingly disposed. The centering catheter further includes a distally disposed centering mechanism that, when activated, centers the ablative guide wire within the blood vessel as it traverses the occlusion. The centering mechanism can comprise various embodiments including a single inflatable balloon or segmented inflatable balloon, which is in fluid communication with an inflation lumen. An airless preparation lumen may be disposed within the inflation lumen for ease of centering catheter preparation. The ablative guide wire includes insulation that is preferably formed of heat shrink tubing, which is stretched prior or concurrently with the heating process. The ablative guide wire includes a distal ablation tip having a non-traumatic structure and at least one discontinuous feature for creating high current densities for more efficient tissue ablation.

Claims

1. A centering catheter for positioning a conductive guide wire in a blood vessel, comprising:

an elongate catheter body having a distal end and an operative lumen, the lumen having a distal end opening, such that a guide wire disposed in the lumen may be advanced beyond the distal end opening; and

a centering mechanism operable to secure the distal end of the catheter body within a blood vessel, such that a distal guide wire tip positioned in the lumen proximate the distal end opening is substantially centered within the blood vessel.

2. The centering catheter of

claim 1

, wherein the centering mechanism comprises an inflatable body defining an interior region, the catheter body further comprising an inflation lumen in communication with the interior region, whereby the inflatable body may be inflated via introduction of a pressurized fluid medium through the inflation lumen.

3. The centering catheter of

claim 2

, wherein the inflatable body includes a distal end side that, when the body is disposed in a blood vessel and inflated, has a substantially flat profile.

4. The centering catheter of

claim 1

, wherein the centering mechanism comprises a plurality of inflatable body segments, each body segment defining a respective interior region, wherein interior regions of adjacent body segments are in fluid communication with each other, the catheter body further comprising an inflation lumen in communication with the interior region of a most proximal body segment, whereby the body segments may be inflated via introduction of a pressurized fluid medium through the inflation lumen.

5. The centering catheter of

claim 4

, wherein the interior regions of adjacent body segments are in fluid communication with each other via the inflation lumen.

6. The centering catheter of

claim 4

, wherein a distal most body segment has a distal wall that, when the respective segment body is disposed in a blood vessel and inflated, has a substantially flat profile.

7. The centering catheter of

claim 4

, further comprising at least one restriction band formed between the inflatable body segments.

8. The centering catheter of

claim 2

, wherein the centering mechanism further comprises a resilient support structure adjacent the inflatable body, the support structure pre-shaped into a complex geometry conforming to the inner wall of a blood vessel.

9. The centering catheter of

claim 8

, wherein the complex geometry is a helix.

10. The centering catheter of

claim 8

, wherein the complex geometry is a bi-planar wave.

11. The centering catheter of

claim 7

, wherein the resilient support structure comprises shape memory material.

12. The centering catheter of

claim 11

, wherein the shape memory material is Nitinol.

13. A method for recanalization of a blood vessel, comprising:

positioning a conductive guide wire having a distal end ablation tip into a blood vessel, such that the ablation tip is adjacent an occlusion to be traversed;

centering the guide wire ablation tip within the blood vessel;

conveying radio frequency (RF) RF energy through the guide wire to the distal ablation tip; and

advancing the energized ablation tip through the occlusion.

14. The method of

claim 13

, wherein the guide wire ablation tip is centered by

advancing a centering catheter over the guide wire until an operable centering mechanism mounted on a distal end of the centering catheter is adjacent the occlusion, the centering catheter comprising a lumen through which the guide wire extends, the lumen having a distal end opening through which the guide wire may be advanced, and

activating the centering mechanism to thereby center the guide wire ablation tip within the blood vessel.

15. The method of

claim 14

, wherein the occlusion lies in a curvilinear region of the blood vessel lumen, and the centering catheter conforms to the curvilinear region.

16. The method of

claim 13

, further comprising

removing the centering catheter from the guide wire;

advancing a therapeutic device over the guide wire until the device is positioned proximate the occlusion, and

operating the therapeutic device.

17. The method of

claim 16

, wherein the therapeutic device is an atheroectomy catheter.

18. The method of

claim 16

, wherein the therapeutic device is an angioplasty catheter.

19. The method of

claim 16

, wherein the occlusion lies in a curvilinear region of the blood vessel, advancement of the ablative guide wire through the occlusion is accomplished via a plurality of ablation procedures, and treatment of the occlusion performed via a plurality of therapeutic procedures.

20. An invasive catheter, comprising:

an elongate catheter body having proximal and distal ends;

an inflatable body mounted to the catheter body proximate the distal end, the inflatable body defining an interior region;

a first lumen extending through the catheter body, the first lumen having a distal opening in communication with the interior region; and

a second lumen disposed within the first lumen, the second lumen having a distal opening in communication with the interior region.

21. The catheter of

claim 20

, wherein the first and second lumens have circular outer walls and wherein the second lumen is concentrically disposed within the first lumen.

22. The catheter of

claim 20

, wherein the interior region of the inflatable body has first and second ends, and wherein the first lumen terminates proximate the first end of the interior region and the second lumen terminates proximate the second end of the interior region.

23. The catheter of

claim 20

, wherein the catheter body further comprises a guide wire lumen having a distal end opening, such that a guide wire disposed in the operative lumen may be advanced beyond the distal end opening, and

wherein the inflatable body is operable to secure the distal end of the catheter body within a blood vessel, such that a guide wire advanced through the distal end lumen opening is substantially centered within the blood vessel.

24. A method of preparing a balloon catheter comprising an elongate catheter body, a distally mounted inflatable body having an interior region, and first and second lumens extending through the elongate catheter body and saving proximal openings, the method comprising:

conveying a medium under pressure into the proximal opening of and through one of the first and second lumens;

conveying the pressurized medium through the interior region of the inflatable body; and

conveying the pressurized medium through the other of the first and second lumens and out of the proximal end thereof.

25. The method of

claim 24

, wherein the first lumen is disposed in the second lumen.

26. The method of

claim 24

, wherein the pressurized medium is contrast agent.

27. The method of

claim 24

, wherein the pressurized medium is conveyed into the proximal end of the first lumen and out of the proximal end of the second lumen.

28. The method of

claim 24

, wherein the pressurized medium is conveyed into the proximal end of the second lumen and out of the proximal end of the first lumen.

29. The method of

claim 24

, wherein the interior region of the inflatable body includes air, and the air is forced out of the proximal end of the other of the first and second lumens with the pressurized medium.

30. The method of

claim 24

, wherein the interior region includes a first and a second end, and wherein the pressurized medium is conveyed from the first end of the interior region to the second end of the interior region.

31. A method for manufacturing an insulated, conductive guide wire for use in intravascular medical procedures, comprising:

placing an insulation tubing over at least a portion of an electrically conductive wire;

stretching the tubing to reduce its thickness to a desired level; and

heating the stretched tubing to thereby adhere the tubing wire.

32. The method of

claim 31

, wherein the stretching and heating steps are performed simultaneously.

33. The method of

claim 31

, wherein the tubing is stretched to a thickness of approximately 0.001 inches.

34. The method of

claim 31

, wherein the wire has proximal and distal end portions, and wherein the tubing is only placed over, and adhered to, the proximal and distal end portions.

35. An ablative guide wire assembly for use in intravascular medical procedures, comprising:

an elongate conductive guide wire having a distal end; and

an ablation tip formed on the guide wire distal end, the ablation tip having a generally non-traumatic structure with a discontinuous feature.

36. The ablative guide wire assembly of

claim 35

, wherein the non-traumatic structure is spherically shaped, and wherein the discontinuous feature comprises a tapered protrusion disposed on a distal facing surface of the structure.

37. The ablative guide wire assembly of

claim 35

, wherein the non-traumatic structure is spherically shaped, and wherein the discontinuous feature comprises a shallow cavity having a generally circumferential edge formed on a distal facing surface of the structure.

38. The ablative guide wire assembly of

claim 35

, wherein the non-traumatic structure is bell-shaped, and wherein the discontinuous feature comprises an elongated conductor extending through the non-traumatic structure.

39. The ablative guide wire assembly of

claim 35

, wherein the non-traumatic structure is spherically shaped, and wherein the discontinuous feature comprises a plurality of tapered protrusions or edges disposed on a distal facing surface of the structure.

40. The ablative guide wire assembly of

claim 35

, wherein the non-traumatic structure is spherically shaped, and wherein the discontinuous feature comprises a plurality of non-conductive particles disposed on a distal facing surface of the structure.

41. The ablative guide wire assembly of

claim 35

, wherein the distal end of the guide wire is shapeable.