Compressible/expandable atherectomy cutter

• US 5,224,945 A
• Filed: 01/13/1992
• Issued: 07/06/1993
• Est. Priority Date: 01/13/1992
• Status: Expired due to Term

• Current Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Interventional Technologies Incorporated (Boston Scientific Corporation)
• Inventors: Pannek, Edward J. Jr.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): LEWIS, WILLIAM W
• Application Number:
  US07/820,089
• Time in Patent Office: 540 Days
• Field of Search: 604/22, 606/155, 606/170, 606/180, 606/191, 606/194, 15/104.19, 128/751-754
• US Class Current: 606/159
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence

Abstract

An expandable and compressible atherectomy cutter for cutting plaque from a stenosis in an artery includes a cutter assembly which, relative to its axis of rotation, has a plurality of radially separated and axially aligned blades. The distal ends of these blades are joined together at a grommet and the proximal ends are free for individual engagement with grooves which are axially oriented on the hub of a rotatable torque tube. Each groove on the hub has a plurality of notches, and each notch in a groove has a corresponding notch in each of the other grooves which lies in the same radial plane and at the same radial distance from the rotational axis of the torque tube. Although notches in different radial planes can have different radial distances, the proximal ends of the blades simultaneously engage with only the notches in the same radial plane. Thus, movement of the cutter assembly relative to the hub causes a concerted movement of the proximal ends of the blades from notches in one radial plane to the notches in another radial plane for radial expansion or contraction of the blades.

Claims

1. A compressible/expandable atherectomy cutter which comprises:

a plurality of cutting blades, each said blade having a distal end and a proximal end;

a grommet for holding said distal ends of said blades together;

means engageable with said proximal ends of said blades for moving said blades between a first configuration wherein said blades are compressed to have a reduced cutting radius and a second configuration wherein said blades are expanded to have an increased cutting radius; and

means for rotating said engageable means with said blades about an axis of rotation.

2. A cutter as recited in claim 1 wherein said rotating means is a torque tube.

3. A compressible/expandable atherectomy cutter which comprises:

a plurality of cutting blades, each said blade having a distal end and a proximal end;

means for holding said distal ends of said blades together;

a hub engageable with said proximal ends of said blades for moving said blades between a first configuration wherein said blades are compressed to have a reduced cutting radius and a second configuration wherein said blades are expanded to have an increased cutting radius, said hub being formed with a plurality of grooves aligned with said axis of rotation, said proximal end of each said blade being slidingly mounted within a separate groove;

a plurality of axially spaced notches formed in each of said grooves, each said notch lying in a radial plane with a corresponding notch in each of the other of said grooves, said notches in each said radial plane being at the same radial distance from said axis of rotation for simultaneous engagement with said proximal ends of said blades to hold said blades in a selected said configuration; and

means for rotating said engageable means with said blades about an axis of rotation.

4. A cutter as recited in claim 3 further comprising a spring means positioned around said blades for urging said proximal ends of said blades into said grooves on said hub.

5. A cutter as recited in claim 4 wherein each said groove is formed with at least a distal notch, a proximal notch and an intermediate notch therebetween, said distal notch and said proximal notch having a first radial distance and said intermediate notch having a second radial distance, said first radial distance being less than said second radial distance to respectively establish said first configuration and said second configuration.

6. A cutter as recited in claim 5 wherein said holding means is formed with a hole and said hub is formed with a hole and said cutter further comprises a guide wire insertable through said hole of said holding means and through said hole of said hub, and further, said guide wire being formed with an abutment positioned proximally from said holding means for urging distally against said holding means to move said blades between said first configuration and said second configuration.

7. A cutter as recited in claim 5 wherein said holding means is formed with a hole and said hub is formed with a hole and said cutter further comprises a guide wire insertable through said hole of said holding means and through said hole of said hub, and further, said guide wire being formed with an abutment positioned distally from said holding means for urging proximally against said holding means to move said blades between said first configuration and said second configuration.

8. A cutter as recited in claim 5 wherein said grooves are angled relative to said axis of rotation to facilitate a cyclical movement of said blades from said first configuration, to said second configuration and return to said first configuration.

9. An atherectomy cutter which comprises:

a rotatable torque tube;

a hub mounted on said rotatable torque tube for rotation therewith;

a guide wire formed with an abutment, said guide wire being slidable inserted through said hub and said torque tube;

a plurality of blades each of said blades having a distal end slidingly engageable with said guide wire and a proximal end engageable with said hub and movable thereon upon urging of said abutment against said distal end to move said blade between a first configuration wherein said blade has a first cutting radius and a second configuration wherein said blade has a second cutting radius, said distal ends of said blades being joined together; and

means for rotating said hub and said torque tube about an axis of rotation.

10. A cutter as recited in claim 9 wherein said first cutting radius is less than said second cutting radius.

11. A cutter as recited in claim 9 wherein said hub is formed with a plurality of grooves aligned with said axis of rotation, said proximal end of each said blade being slidingly mounted within a separate groove, and each said groove is formed with a plurality of axially spaced notches, each said notch lying in a radial plane with a corresponding notch in each of the other of said grooves, said notches in each said radial plane being at the same radial distance from said axis of rotation for simultaneous engagement with said proximal ends of said blades to hold said blades in a selected said configuration.

12. A cutter as recited in claim 9 wherein each said groove is formed with at least a distal notch, a proximal notch and an intermediate notch therebetween, said distal notch and said proximal notch having a first radial distance and said intermediate notch having a second radial distance, said first radial distance being less than said second radial distance to respectively establish said first configuration and said second configuration.

13. A cutter as recited in claim 9 further comprising a spring means positioned around said blades for urging said proximal ends of said blades into said grooves on said hub.

14. A method for using an atherectomy cutter to excise plaque from the artery of a patient which comprises the steps of:

providing an atherectomy cutter having a rotatable torque tube, a hub mounted on said rotatable torque tube for rotation therewith, a guide wire formed with an abutment, said guide wire being slidable inserted through said hub and said toque tube, and a plurality of blades, each said blade having a distal end slidingly engageable with said guide wire and a proximal end engageable with said hub and movable thereon upon urging said abutment against said distal ends of said blades to move said blades between a first configuration wherein said blades establish a first cutting radius and a second configuration wherein said blades establish a second cutting radius;

configuring said cutter in said first configuration;

inserting said cutter into the artery of a patient and positioning said cutter against the plaque to be excised;

expanding said cutter into said second configuration by positioning the abutment on said guide wire distally from said distal end of said blades and pulling proximally on said guide wire to urge said abutment against said distal ends of said blades to change said configuration thereof; and

rotating and advancing said cutter into said artery to excise the plaque.

15. A method as recited in claim 14 wherein said first cutting radius is less than said second cutting radius.

16. A method for using an atherectomy cutter to excise plaque from the artery of a patient which comprises the steps of:

providing an atherectomy cutter having a rotatable torque tube, a hub mounted on said rotatable torque tube for rotation therewith, a guide wire formed with an abutment, said guide wire being slidable inserted through said hub and said toque tube, and a plurality of blades, each said blade having a distal end slidingly engageable with said guide wire and a proximal end engageable with said hub and movable thereon upon urging said abutment against said distal ends of said blades to move said blades between a first configuration wherein said blades establish a first cutting radius and a second configuration wherein said blades establish a second cutting radius;

configuring said cutter in said first configuration;

inserting said cutter into the artery of a patient and positioning said cutter against the plaque to be excised;

expanding said cutter into said second configuration by positioning the abutment on said guide wire distally from said distal end of said blades and pushing distally on said guide wire to urge said abutment against said distal ends of said blades to change said configuration thereof; and

rotating and advancing said cutter into said artery to excise the plaque.