Rotationally expandable atherectomy cutter assembly

• US 5,192,291 A
• Filed: 01/13/1992
• Issued: 03/09/1993
• Est. Priority Date: 01/13/1992
• Status: Expired due to Fees

• Current Assignee: Interventional Technologies Incorporated (Boston Scientific Corporation)
• Original Assignee: Interventional Technologies Incorporated (Boston Scientific Corporation)
• Inventors: Pannek, Edward J. Jr.
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): Lewis, William W.
• Application Number:
  US07/820,754
• Time in Patent Office: 421 Days
• Field of Search: 606/159, 606/170, 606/127, 606/128, 606/180, 606/191, 606/198, 604/22, 604/104-108, 128/751-754, 15/104.19
• US Class Current: 606/159
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence

Abstract

A rotationally expandable atherectomy cutter assembly for cutting plaque from a stenosis in an artery includes a plurality of radially separated and axially aligned blade elements. The distal ends of each blade element are fixably connected to a hub and the proximal ends of each blade element slidably engage helical slots formed in a distally flared extension tube of the assembly. The extension tube is connectable to a rotatable catheter. The helical slots are oriented in a first direction such that contact of the cutter assembly with the plaque of the stenosis, in conjunction with a second direction rotation of the catheter causes the proximal ends of the blade assembly to slide distally along the helical slots thereby expanding the cutting radius of the cutter assembly.

Claims

1. An atherectomy cutter assembly having a longitudinal axis, said cutter assembly comprising:

a plurality of blade elements radially spaced about said longitudinal axis, each of said blade elements having a distal end and a proximal end;

a hub at said distal ends of said blade elements wherein said distal ends of said blade elements are fixably connected to said hub; and

an extension tube positioned coaxially with said blade elements, said tube having a plurality of helical slots formed therein extending in a direction of said longitudinal axis and slidably retaining each of said proximal ends of said blade elements.

2. An atherectomy cutter assembly as recited in claim 1 wherein said extension tube is distally flared.

3. An atherectomy cutter assembly as recited in claim 1 wherein said extension tube is substantially cylindrical and hollow with openings at a proximal end and a distal end of said tube.

4. An atherectomy cutter assembly as recited in claim 1 further comprising a tubular union engaging said extension tube and connectable to a hollow catheter.

5. An atherectomy cutter assembly as recited in claim 4 wherein said union and said extension tube form a continuous passageway from said blade elements to said hollow catheter.

6. An atherectomy cutter assembly as recited in claim 4 wherein said union is integral with said extension tube.

7. An atherectomy cutter assembly having a longitudinal axis, said cutter assembly comprising:

a plurality of blade elements radially spaced about said longitudinal axis, each of said blade elements having a distal end, a proximal end, and a cutting blade oriented substantially parallel to said longitudinal axis;

a hub at said distal ends of said blade elements wherein said distal ends of said blade elements are fixably connected to said hub; and

an extension tube positioned coaxially with said blade elements, said tube having a plurality of slots formed therein extending in a direction of said longitudinal axis and slidably retaining each of said proximal ends of said blade elements.

8. An atherectomy cutter assembly as recited in claim 7 wherein said cutting blades define a cutting radius greater than the radius of said extension tube.

9. A rotationally expandable atherectomy cutter assembly having a longitudinal axis, said cutter assembly comprising:

a plurality of blade elements radially spaced about said longitudinal axis, each of said blade elements having a distal end, a proximal end and a cutting blade therebetween oriented substantially parallel to said longitudinal axis;

a hub at said distal ends of said blade elements wherein said distal ends of said blade elements are fixably connected to said hub;

a distally flared extension tube positioned coaxially with said blade elements, wherein said tube is substantially cylindrical and hollow and has openings at a proximal end and a distal end of said tube;

a union engaging said extension tube and connectable to a hollow catheter to form a continuous passageway from said blade elements to said hollow catheter; and

a plurality of helical slots formed in said tube wherein each of said proximal ends of said blade elements is slidably retained in one of said slots, and wherein said tube is rotatable about said axis in a first direction of curvature and said plurality of helical slots are oriented in a second direction of curvature substantially opposite said first direction of curvature such that when said cutter assembly encounters resistance to rotation in said first direction of curvature, said proximal ends of said blade elements slide distally along said slots, thereby expanding the cutting radius of said cutting blades.

10. A rotationally expandable atherectomy cutter assembly as recited in claim 9 wherein said cutting blades define a cutting radius greater than the radius of said extension tube.

11. A rotationally expandable atherectomy cutter assembly as recited in claim 9 wherein said union is integral with said extension tube.

12. An atherectomy cutter assembly having a longitudinal axis and rotationally expandable from a contracted position to an expanded position, said cutter assembly comprising:

a plurality of blade elements radially spaced about said longitudinal axis, each of said blade elements having a distal end, a proximal end and a cutting blade therebetween oriented substantially parallel to said longitudinal axis;

a hub at said distal ends of said blade elements wherein said distal ends of said blade elements are fixably connected to said hub;

a distally flared extension tube positioned coaxially with said blade elements;

a plurality of helical slots, each having a proximal and distal end, formed in said tube, wherein each of said proximal ends of said blade elements is slidably retained in one of said slots, and wherein said tube is rotatable about said axis in a first direction of curvature and said plurality of helical slots are oriented in a second direction of curvature substantially opposite said first direction of curvature;

further wherein said proximal ends of said blade elements substantially abut said proximal ends of said slots when said assembly is in said contracted position and said proximal ends of said blade elements substantially abut said distal ends of said slots when said assembly is in said expanded position, and wherein transition from said contracted position to said expanded position is actuated when said cutter assembly encounters resistance to rotation in said first direction of curvature.

13. An atherectomy cutter assembly as recited in claim 12 wherein said cutting blades define a cutting radius greater than the radius of said extension tube.

14. An atherectomy cutter assembly as recited in claim 13 wherein the cutting radius of said cutting blades is greater in said expanded position than in said contracted position.

15. An atherectomy cutter assembly as recited in claim 12 wherein said extension tube is substantially cylindrical and hollow with openings at a proximal end and a distal end of said tube.

16. An atherectomy cutter assembly as recited in claim 12 further comprising a tubular union engaging said extension tube and connectable to a hollow catheter.

17. An atherectomy cutter assembly as recited in claim 16 wherein said union and said extension tube form a continuous passageway from said blade elements to said hollow catheter.