Expandable atherectomy burr and method of ablating an occlusion from a patient's blood vessel

• US 6,096,054 A
• Filed: 10/23/1998
• Issued: 08/01/2000
• Est. Priority Date: 03/05/1998
• Status: Expired due to Fees

• Current Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Gordon, Lucas S., Hefner, Matt, Wulfman, Edward, Hamilton, Eric B., Wyzgala, Mark, Hiblar, Tom, Baumgarten, Donald
• Primary Examiner(s): Smith, Jeffrey A.
• Application Number:
  US09/178,449
• Time in Patent Office: 648 Days
• Field of Search: 606/159, 606/170, 606/180
• US Class Current: 606/170
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 17/320758 with a rotating cutting instrument, e.g. motor driven A61B17/320725, A61B17/32075 and A61B17/320783 take precedence; for removing intra-ocular material A61F9/00763; endoscopic rotatable cutting instruments A61B17/32002
• CPC Class Codes: A61B 2017/00557 inflatable A61B2017/22051 takes precedence
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 2017/320004 abrasive
• CPC Class Codes: A61B 2017/320733 with a flexible cutting or scraping element, e.g. with a whip-like distal filament member

Abstract

An atherectomy burr has an operating diameter that is larger than the diameter of a catheter in which the burr is routed. The burr may include a polymeric balloon that is coated with an abrasive and that expands when the burr is rotated. Alternatively, the burr may include a polymeric tube that is coated with an abrasive and secured to the proximal end of the burr. When the burr is rotated, the polymeric tube expands by centrifugal force. Alternatively, the burr may comprise a metallic strip wound over a mandrel. When the strip is tightly coiled to the mandrel, its outer diameter decreases. The outer diameter of the burr increases as the metallic strip expands. In addition, the burr can be formed as a wire spring wound over a drive tube. The distal end of the spring is coupled to a nose cone that can move within a distal lumen in the drive tube. The maximum expansion of the burr is controlled by the distance that the nose cone can be retracted into the lumen. In addition, the present invention includes a burr having an indexable outer diameter. Various indexing mechanisms are disclosed for selectively increasing or decreasing the distance between a proximal and distal end of the burr. As the length of the burr changes, the outer diameter of a number of cutting blades is changed to allow a physician to create different sized lumens in a patient'"'"'s vessel.

Claims

1. An atherectomy device for ablating an occlusion in a patient'"'"'s blood vessel, comprising:

a drive shaft;

an ablation burr secured to the drive shaft, the burr including a polymeric balloon having an unexpanded state with a first diameter and an expanded state with a second larger diameter, the polymeric balloon further including an abrasive coating disposed on at least a portion of its exterior surface to ablate an occlusion in a patient'"'"'s vessel; and

a lumen extending through the drive shaft and ablation burr for receiving a guide wire.

2. The atherectomy device of claim 1, wherein the ablation burr further comprises:

a tube including one or more holes disposed at the distal end of the drive shaft, wherein the polymeric balloon is disposed over the tube.

3. The atherectomy device of claim 2, wherein the tube includes one or more holes disposed on an outer surface thereof for passage of a fluid into and out of the polymeric balloon.

4. The atherectomy device of claim 1, wherein the polymeric balloon is made of a non-stretchable plastic.

5. The atherectomy device of claim 1, wherein the polymeric balloon assumes the expanded state when rotated by the drive shaft.

6. An atherectomy device for ablating an occlusion in a patient'"'"'s blood vessel, comprising:

a drive shaft;

an ablation burr secured to the drive shaft, the burr including a nose section having a fixed maximum diameter and a polymeric section having an abrasive disposed on at least a portion thereof, the polymeric section having a diameter that increases as the burr is rotated by the drive shaft; and

a lumen extending through the drive shaft and ablation burr for receiving a guide wire.

7. The atherectomy device of claim 6, wherein the ablation burr comprises a core with the nose section having a maximum diameter approximately midway along a length of the burr and tapering toward a distal end of the burr and a stepped section of a substantially constant diameter that is smaller than the maximum diameter of the nose section, wherein the polymeric section comprises a polymeric tube disposed over the stepped section.

8. The atherectomy device of claim 7, wherein an end of the polymeric tube is spaced from the drive shaft.

9. The atherectomy device of claim 7, wherein the polymeric tube engages the drive shaft.

10. The atherectomy device of claim 9, wherein the polymeric tube includes one or more holes disposed around a circumference thereof.

11. The atherectomy device of claim 6, wherein the polymeric section includes one or more fibers that limit the expansion of the polymeric section when the ablation burr is rotated by the drive shaft.

12. An atherectomy device for ablating an occlusion in a patient'"'"'s blood vessel, comprising:

a drive shaft;

a mandrel coupled to the drive shaft;

a compressible strip wound around the mandrel, the compressible strip including an abrasive disposed on at least a portion thereof for ablating an occlusion, the strip having a first diameter when the strip is tightly coiled around the mandrel and a second, larger diameter when not tightly coiled around the mandrel; and

a lumen extending through the drive shaft and mandrel for receiving a guide wire.

13. The atherectomy device of claim 12, wherein the ablation burr has a diameter at its proximal and distal ends that is smaller than a diameter at a midpoint of the burr.

14. The atherectomy device of claim 12 wherein the mandrel includes a slot and the expandable strip includes a tab that cooperates with the slot to secure the metallic strip to the mandrel.

15. The atherectomy device of claim 12, wherein the expandable strip is made of a superelastic metal.

16. An atherectomy device for ablating an occlusion from a patient'"'"'s vessel, comprising:

a drive shaft;

an ablation burr coupled to the drive shaft that includes a number of cutting blades having an abrasive disposed thereon, the cutting blades including a first end coupled to a distal end of the burr and a second end coupled to a proximal end of the burr, the burr further including an indexing mechanism for selectively changing a maximum outer diameter of the burr, and

a lumen extending through the drive shaft and ablation burr for receiving a guide wire.

17. The atherectomy device of claim 16 wherein the indexing mechanism changes a length between the distal and proximal ends of the burr in order to change the maximum outer diameter of the burr.

18. The atherectomy device of claim 17, wherein the indexing mechanism comprises:

an indexing ring disposed on a distal tube, the indexing ring having a number of slots having varying depths, each slot including an edge that is canted with respect to the longitudinal axis of the distal tube and an edge that is substantially parallel with respect to the longitudinal axis of the distal tube;

a proximal drive tube attached to a drive shaft and is slidably secured to the proximal end of the distal tube, the proximal drive tube including a distal rim having a number of teeth disposed thereon; and

a slide washer that fits over the indexing ring, the slide washer including a proximal rim with a number of teeth that engage the teeth on the proximal drive tube, the slide washer also including a pin that rides along the edges of the slots on the indexing ring, the pin seating in one of the slots to change the distance between the proximal and distal ends of the burr in order to change the maximum outer diameter of the ablation burr.

19. The atherectomy device of claim 18, wherein the pin on the slide washer rotates around the indexing ring to seat in each of the slots.

20. The atherectomy device of claim 18, wherein the serpentine channel includes a number of steps that direct the pin in a predefined direction within the channel.

21. The atherectomy device of claim 17, wherein the indexing mechanism comprises:

a drive tube disposed at the distal end of the drive shaft, the drive tube including a race that extends around the perimeter of the drive tube and is centered with respect to a longitudinal axis of the drive tube and a number of ratchet teeth that extend around the perimeter of the drive tube;

a traveling ball disposed in the race;

a proximal locking tube that extends over the drive tube including a hole through which a portion of the traveling ball extends and a ratchet tab that engages the ratchet teeth on the drive tube;

a distal locking tube that is coupled to the distal end of the burr, the distal locking tube being slidably aligned with the proximal locking tube; and

a traveling tube positioned over the distal and proximal locking tubes, the traveling tube including a hole that receives the traveling ball, and a distal rim that limits the travel of the distal locking tube with respect to the proximal locking tube wherein the traveling ball moves in the race and moves the traveling tube along the length of the drive tube in order to change a maximum outer diameter of the burr.

22. The atherectomy device of claim 19, wherein the indexing mechanism comprises:

a drive tube disposed at the end of the drive shaft, the drive tube including a serpentine channel that extends around the drive tube, the channel including a number of bends that are located at varying positions along the drive tube;

a distal locking tube that is coupled to the distal end of the burr and is slidably aligned with the drive tube; and

a traveling tube disposed over the drive tube and the distal locking tube, the traveling tube including a pin that moves in the serpentine channel and rests in one of the number of bends to move the traveling tube along the length of the drive tube in order to change a maximum outer diameter of the burr.

23. The atherectomy device of claim 16, wherein the cutting blades extend radially outward from a ring at the distal end of the burr and are folded over the burr and secured at the proximal end of the burr.

24. A method of ablating an occlusion from a patient'"'"'s blood vessel, comprising:

advancing a guide wire into a patient'"'"'s vasculature to the occlusion;

advancing an atherectomy device over the guide wire, the ablation device having a drive shaft that includes;

a polymeric section having a diameter that increases when rotated by the drive shaft; and

an abrasive coating disposed on at least a portion of polymeric section;

rotating the drive shaft to expand the diameter of the polymeric section; and

advancing the atherectomy device into the occlusion to ablate it.

25. The method of claim 24, further comprising controlling the rate of rotation of the drive shaft to control the expansion of the polymeric section.