ROTATIONAL ATHERECTOMY SEGMENTED ABRADING HEAD AND METHOD TO IMPROVE ABRADING EFFICIENCY

• US 20100211088A1
• Filed: 02/19/2009
• Published: 08/19/2010
• Est. Priority Date: 02/19/2009
• Status: Active Grant

• Current Assignee: Cardiovascular Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiovascular Systems Incorporated (Boston Scientific Corporation)
• Inventors: Narveson, Christopher M.
• Granted Patent: US 8,628,550 B2
• Time in Patent Office: Days
• US Class Current: 606/159
• 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 2017/320004 abrasive
• CPC Class Codes: A61B 2017/320766 eccentric

Abstract

The invention provides a rotational atherectomy system, device and method having, in various embodiments, a flexible, elongated, rotatable drive shaft comprising an eccentric abrading head comprising at least one eccentric abrading cylindrical segments attached to the drive shaft and in spaced proximity with proximal and a distal conical segments. Each individual abrading segment, comprises a first tissue removing surface, typically an abrasive coating on the outer surface, that is designed to abrade calcified, hard tissue and abrasive coating on the leading and trailing surfaces designed to abrade non-calcified, soft tissue. Each abrading segment, as well as the abrading head comprising the collective segments, has a center of mass spaced radially from the rotational axis of the drive shaft, facilitating the ability of the device to open the stenotic lesion to a diameter larger than the outer diameter of the enlarged abrading head when operated at high speeds.

Claims

1. A high-speed rotational atherectomy device for opening a stenosis in an artery having a given diameter, comprising:

a guide wire having a maximum diameter less than the diameter of the artery;

a flexible elongated, rotatable drive shaft advanceable over the guide wire, the drive shaft having a rotational axis; and

an eccentric abrading head attached to the drive shaft, the abrading head comprising a proximal section, a distal section and an intermediate section between the proximal and distal sections, and at least two flexibility gaps, one of the at least two flexibility gaps located between the proximal section and the intermediate section and a second flexibility gap located between the intermediate section and the distal section, and wherein the abrading head defines a drive shaft lumen therethrough.

2. The rotational atherectomy device of claim 1, wherein the proximal section comprises a proximal conical section.

3. The rotational atherectomy device of claim 2, wherein the proximal section further comprises a proximal cylindrical section.

4. The rotational atherectomy device of claim 2, wherein the distal section comprises a distal conical section.

5. The rotational atherectomy device of claim 3, wherein the distal section comprises a distal conical section and a distal cylindrical section.

6. The rotational atherectomy device of claim 1, wherein the intermediate section comprises at least one eccentric abrading cylindrical segment.

7. The rotational atherectomy device of claim 6, wherein the at least one eccentric abrading cylindrical segment is in spaced proximity with the proximal segment and with the distal segment.

8. The rotational atherectomy device of claim 7, further comprising two or more eccentric abrading cylindrical segments, wherein each of the two or more eccentric abrading cylindrical segments are adjacent to at least one eccentric abrading cylindrical segment and in spaced proximity with the at least one adjacent eccentric abrading cylindrical segment.

9. The rotational atherectomy device of claim 6, wherein the total number of flexibility gaps comprises the number of eccentric abrading cylindrical segments plus one.

10. The rotational atherectomy device of claim 6, wherein the at least one eccentric abrading cylindrical segment comprises an outer surface and a proximal inner surface and a distal inner surface, the outer surface, proximal inner surface and distal inner surface comprising abrasive surfaces.

11. The rotational atherectomy device of claim 10, wherein the outer surface comprises abrasive that is optimized for calcified stenotic tissue and wherein the proximal inner surface and distal inner surface comprise abrasive that is optimized for soft, non-calcified stenotic tissue.

12. The rotational atherectomy device of claim 1, wherein the eccentric abrading head comprises a center of mass that is offset from the rotational axis of the drive shaft.

13. The rotational atherectomy device of claim 12, wherein the proximal section and distal section each comprise a center of mass that is offset from the rotational axis of the drive shaft.

14. The rotational atherectomy device of claim 12, wherein the at least one eccentric abrading cylindrical segment comprises a center of mass that is spaced radially away from the rotational axis of the drive shaft.

15. The rotational atherectomy device of claim 14, wherein the center of mass of the eccentric abrading head comprises an offset from the rotational axis of the drive shaft that may be controlled by adding or removing one or more of the at least one eccentric abrading cylindrical segments.

16. The rotational atherectomy device of claim 12, wherein the eccentric abrading head has a maximum resting diameter between about 1.0 mm and about 1.5 mm, and the center of mass is spaced away from the rotational axis of the drive shaft by a distance of at least about 0.013 mm.

17. The rotational atherectomy device of claim 12, wherein the eccentric abrading head has a maximum resting diameter between about 1.5 mm and about 1.75 mm, and the center of mass is spaced away from the rotational axis of the drive shaft by a distance of at least about 0.03 mm.

18. The rotational atherectomy device of claim 12, wherein the eccentric abrading head has a maximum resting diameter between about 1.75 mm and about 2.0 mm, and the center of mass is spaced away from the rotational axis of the drive shaft by a distance of at least about 0.06 mm.

19. The rotational atherectomy device of claim 12, wherein the eccentric abrading head has a maximum resting diameter of at least about 2.0 mm, and the center of mass is spaced away from the rotational axis of the drive shaft by a distance of at least about 0.1 mm.

20. The rotational atherectomy device of claim 12, wherein the eccentric abrading head has a maximum resting diameter between about 1.0 mm and about 1.5 mm, and the center of mass is spaced away from the rotational axis of the drive shaft by a distance of at least about 0.02 mm.

21. The rotational atherectomy device of claim 12, wherein the eccentric abrading head has a maximum resting diameter between about 1.5 mm and about 1.75 mm, and the center of mass is spaced away from the rotational axis of the drive shaft by a distance of at least about 0.05 mm.

22. The rotational atherectomy device of claim 12, wherein the eccentric abrading head has a maximum resting diameter between about 1.75 mm and about 2.0 mm, and the center of mass is spaced away from the rotational axis of the drive shaft by a distance of at least about 0.1 mm.

23. The rotational atherectomy device of claim 1, wherein the at least two flexibility gaps allow for flexion between the at least one eccentric abrading cylindrical segment, the proximal segment and the distal segment.

24. A method for opening a stenosis in an artery having a given diameter, comprising:

providing a guide wire having a maximum diameter less than the diameter of the artery;

advancing the guide wire into the artery to a position proximal to the stenosis;

providing a flexible elongated, rotatable drive shaft advanceable over the guide wire, the drive shaft having a rotational axis;

an eccentric abrading head attached to the drive shaft, the abrading head comprising a proximal section, a distal section and an intermediate section between the proximal and distal sections, and at least two flexibility gaps, one of the at least two flexibility gaps located between the proximal section and the intermediate section and a second flexibility gap located between the intermediate section and the distal section, and wherein the abrading head defines a drive shaft lumen therethrough;

advancing the drive shaft over the guide wire wherein the at least one eccentric abrading head is adjacent the stenosis;

rotating the drive shaft and attached eccentric abrading head at a speed between 20,000 and 200,000 rpm;

translating the eccentric abrading head proximally and distally across the stenosis;

creating an orbital path traversed by the eccentric abrading head; and

abrading the stenosis with the eccentric abrading head.

25. A method for abrading soft stenotic tissue in an artery having a given diameter, comprising:

providing a guide wire having a maximum diameter less than the diameter of the artery;

advancing the guide wire into the artery to a position proximal to the stenosis;

providing a flexible elongated, rotatable drive shaft advanceable over the guide wire, the drive shaft having a rotational axis;

providing an eccentric abrading head attached to the drive shaft, the abrading head comprising a proximal section, a distal section and an intermediate section between the proximal and distal sections, and at least two flexibility gaps, one of the at least two flexibility gaps located between the proximal section and the intermediate section and a second flexibility gap located between the intermediate section and the distal section, and wherein the abrading head defines a drive shaft lumen therethrough;

advancing the drive shaft over the guide wire wherein the at least one eccentric abrading head is adjacent the stenosis;

rotating the drive shaft and attached eccentric abrading head at a speed between 20,000 and 200,000 rpm;

translating the eccentric abrading head proximally and distally across the stenosis;

enabling the soft stenotic tissue to expand into the at least two flexibility gaps; and

abrading the soft stenotic tissue.

26. A method for controlling the rotational diameter of an eccentric abrading head in an artery having a given diameter, comprising:

providing a guide wire having a maximum diameter less than the diameter of the artery;

advancing the guide wire into the artery to a position proximal to the stenosis;

providing a flexible elongated, rotatable drive shaft advanceable over the guide wire, the drive shaft having a rotational axis;

providing an eccentric abrading head attached to the drive shaft, the abrading head comprising a proximal section, a distal section and an intermediate section between the proximal and distal sections, the intermediate section comprises one eccentric abrading cylindrical segment wherein the center of mass of the eccentric abrading cylindrical segment is radially offset from the rotational axis of the drive shaft and wherein the at least one eccentric abrading cylindrical segment is in spaced proximity with the proximal segment and with the distal segment, and at least two flexibility gaps, one of the at least two flexibility gaps located between the proximal section and the intermediate section and a second flexibility gap located between the intermediate section and the distal section, and wherein the abrading head defines a drive shaft lumen therethrough;

adding at least one eccentric abrading cylindrical segment, having a center of mass that is offset from the rotational axis of the drive shaft, to the intermediate section advancing the drive shaft over the guide wire wherein the at least one eccentric abrading head is adjacent the stenosis; and

rotating the drive shaft and attached eccentric abrading head at a controlled speed between 20,000 and 200,000 rpm.

27. The method of claim 26, further comprising removing at least one eccentric abrading cylindrical segment from the intermediate section.