Eccentric abrading and cutting head for high-speed rotational atherectomy devices

Patent metadata

Field	Value
Publication number	US-9055966-B2
Application number	US-58059009-A
Country	US
Kind code	B2
Filing date	Oct 16, 2009
Priority date	May 30, 2008
Publication date	Jun 16, 2015
Grant date	Jun 16, 2015

Abstract

The invention provides a rotational atherectomy device having, in various embodiments, a flexible, elongated, rotatable drive shaft with at least one flexible or inflexible eccentric enlarged abrading and cutting head attached thereto which comprises an abrasive surface. When placed against stenotic tissue and rotated at high speed, the eccentric nature of the abrading and cutting head moves along an orbital path, opening the lesion to a diameter larger than the resting diameter of the enlarged abrading and cutting head. Preferably the abrading and cutting head has a center of mass spaced radially from the rotational axis of the drive shaft, facilitating the ability of the device to travel along an orbital path. The abrading and cutting head comprises proximal and/or distal radiused surfaces that facilitate cutting difficult stenosis material while minimizing trauma to the vessel. In some cases, the abrading and cutting head is made from a relatively dense metal.

First claim

We claim:

1. A high-speed rotational atherectomy device for opening a stenosis in an artery, comprising:
a guide wire having a maximum diameter less than a diameter of the artery;
a flexible elongated, rotatable drive shaft advanceable over the guide wire and having a rotational axis; and
a single piece unitary construction eccentric abrading head secured to the drive shaft and comprising proximal, intermediate and distal portions;
wherein the proximal portion comprises a proximal outer surface having diameters that increase distally and a radiused proximal leading edge;
wherein the intermediate portion comprises a cylindrical intermediate outer surface that includes at least one tissue removal section;
wherein the distal portion comprises a distal outer surface having diameters that decrease distally, the intermediate portion disposed between the proximal and distal portions;
wherein the abrading head defines a drive shaft lumen therethrough at least partially traversed by the drive shaft; and
wherein the abrading head has a center of mass radially displaced from a surface of the drive shaft.

2. The device of claim 1 , wherein the abrading head is formed from a material having a density in the range of 8-22.5 g/cm 3 .

3. The device of claim 1 , wherein the abrading head is formed from tantalum or an alloy of tantalum.

4. The device of claim 1 , wherein the abrading head is formed from tungsten or an alloy of tungsten.

5. The device of claim 1 , wherein the abrading head is formed from molybdenum or an alloy of molybdenum.

6. The device of claim 1 , wherein the abrading head is formed from iridium or an alloy of iridium.

7. The device of claim 1 , wherein
the abrading head comprises a hollow chamber having a size and a shape; and
a location of the center of mass is affected by the size and shape of the hollow chamber.

8. The device of claim 1 , wherein
the abrading head comprises a geometric center; and
the center of mass and the geometric center are coincident.

9. The device of claim 1 , wherein
at least a portion of the drive shaft traversing through the abrading head deflects radially away from its nominal rotational axis during use; and
a stiffness of the drive shaft affects
an extent of the radial deflection of the drive shaft; and
an abrading diameter of the device.

10. The device of claim 9 , wherein a density of a material forming the abrading head further affects the extent of the radial deflection and the abrading diameter.

11. The device of claim 1 , wherein a density of a material forming the abrading head affects:
a location of the center of mass;
an eccentricity of the abrading head; and
an abrading diameter of the device.

12. 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
at least one eccentric single piece unitary construction abrading head attached to the drive shaft, the abrading head comprising:
a center of mass radially offset from a surface of the drive shaft;
a proximal portion comprising a proximal outer surface and a length;
an intermediate portion comprising a tissue removal section on at least a portion of a cylindrical outer surface thereof; and
a distal portion comprising a distal outer surface and a length; wherein,
the lengths of the proximal and the distal portions are unequal;
the proximal outer surface comprises:
a proximal radiused leading edge; and
diameters that increase distally;
the distal outer surface comprising diameters that decrease distally; and
the abrading head defines a drive shaft lumen therethrough at least partially traversed by the drive shaft.

13. The device of claim 12 , wherein the abrading head is formed from a material having a density in the range of 8-22.5 g/cm 3 .

14. The device of claim 12 , wherein the abrading head is formed from tantalum or an alloy of tantalum.

15. The device of claim 12 , wherein the abrading head is formed from tungsten or an alloy of tungsten.

16. The device of claim 12 , wherein the abrading head is formed from molybdenum or an alloy of molybdenum.

17. The device of claim 12 , wherein the abrading head is formed from iridium or an alloy of iridium.

18. The device of claim 12 , wherein
the abrading head comprises a hollow chamber having a size and a shape; and
a location of the center of mass is affected by the size and shape of the hollow chamber, and the lengths of the proximal and the distal portions.

19. The device of claim 12 , wherein
the abrading head comprises a geometric center; and
the center of mass and the geometric center are coincident.

20. The device of claim 12 , wherein
at least a portion of the drive shaft traversing through the abrading head deflects radially away from its nominal rotational axis during use; and
a stiffness of the drive shaft affects
an extent of the radial deflection of the drive shaft; and
an abrading diameter of the device.

21. The device of claim 20 , wherein a density of a material forming the abrading head further affects the extent of the radial deflection and the abrading diameter.

22. The device of claim 12 , wherein a density of a material forming the abrading head affects:
a location of the center of mass;
an eccentricity of the abrading head; and
an abrading diameter of the device.

Assignees

• Cambronne Matthew D
• Plowe Charles A
• Cardivascular Systems

Inventors

• Cambronne Matthew D
• Plowe Charles A

Classifications

• A61B2017/320766

  eccentric · CPC title

• A61B17/32002 Primary

  with continuously rotating, oscillating or reciprocating cutting instruments · CPC title

• A61B2017/320004

  abrasive · CPC title

• A61B17/3207

  Atherectomy devices {working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions (A61B17/32037 takes precedence; endoscopic cutting instruments A61B17/320016)} · CPC title