Bi-axial cutter apparatus for catheter

• US 5,441,510 A
• Filed: 05/27/1994
• Issued: 08/15/1995
• Est. Priority Date: 09/01/1993
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: The Technology Development Company
• Inventors: Orth, Geoffrey A., Anderson, Scott C., Simpson, John B., Brown, Peter S., Frantzen, John J., Cannon, James M. Jr.
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): Lewis, William
• Application Number:
  US08/250,319
• Time in Patent Office: 445 Days
• Field of Search: 606/159, 606/170, 606/171, 606/180, 604/22
• US Class Current: 606/159
• CPC Class Codes: A61B 17/320783 through side-hole, e.g. sliding or rotating cutter inside catheter

Abstract

An cutter apparatus for removing obstructive tissue has a distal housing having a window for invaginating tissue. An axially reciprocating and rotating cutting blade makes successive longitudinal cuts while slowly rotating across the open window. An axial guide assembly holds the cutting edge of the blade in a cutting path immediately adjacent to the inner surface of the housing. The shape and motion of the cutting blade pares off a generally uniformly thick slice of tissue from the stenosis and directs it toward the interior of the housing. A spiral parting edge opposed to the rotating cutting edge provides clean separation of the tissue slice from the stenosis. The tissue slice is received in a chamber internal to the housing and is retained by the blade and guide assembly for later removal from the patient.

Claims

1. A cutter apparatus for use with a catheter within a biological conduit, comprising:

a tubular member defining a housing, the housing having a window for intimate contact with tissue in the biological conduit, the window including a distal edge and a proximal edge and having an edge between the distal and proximal edges having at least one contiguous submultiple edge defining a parting edge, each submultiple edge including at least one spiral increment; and

a cutter assembly including;

cutting means for cutting tissue within the biological conduit,

means for rotating the cutting means within the housing, and

means for translating the cutting means within the housing,

whereby the cutting means is adapted to remove a slice of tissue from within the biological conduit by rotating and translating the cutting means.

2. The cutter apparatus as set forth in claim 1, wherein there is a plurality of submultiple edges each having at least one spiral cutting increment, the spiral cutting increments defining a continuous line along each respective submultiple edge.

3. The cutter apparatus as set forth in claim 2, wherein the housing includes an inner circumference and wherein the cutting means includes a slidable and rotatable blade cutting edge lying adjacent to a surface defined by the inner circumference of the housing.

4. The cutter apparatus as set forth in claim 3, wherein the means for rotating the cutting means defines a direction of rotation and the blade edge defines a cutting direction facing in the direction of rotation,

whereby the parting edge and the blade edge cooperate for removing a slice of tissue from the biological conduit tissue by separating the slice from the conduit tissue by rotating and translating the blade edge past the parting edge in the cutting direction.

5. A cutter apparatus for use with a catheter within a biological conduit, comprising:

a tubular member defining a housing, the housing having a window for intimate contact with tissue in the biological conduit; and

a cutter assembly including;

cutting means for cutting tissue within the biological conduit,

means for rotating the cutting means within the housing, including a rotational limit means for limiting the extent of a rotational cutting stroke of the cutting means, the rotation being limited to a preselected portion of one complete rotation, the means for limiting rotation having a first limit defining the beginning of a rotational cutting stroke wherein the cutting means is positioned prior to cutting tissue in contact with the housing window, the means for limiting rotation further having a second limit defining the end of the rotational cutting stroke wherein the cutting means is positioned after completing a cutting stroke past the housing window, and

means for translating the cutting means within the housing,

whereby the cutting means is adapted to remove a slice of tissue from within the biological conduit by rotating and translating the cutting means.

6. A cutter apparatus for use with an atherectomy catheter, comprising:

a tubular member defining an atherectomy catheter outer housing, the outer housing having outer and inner surfaces, the outer housing further having a window for intimate contact with tissue in a biological conduit;

a cutter means within the outer housing, the cutter means including;

means for rotating the cutter means within the outer housing, said means defining a direction of rotation,

means for translating the cutter means within the outer housing, and

blade means for cutting tissue within the biological conduit, the blade means having a slidable and rotatable blade edge for cutting tissue, the blade edge configured to lie immediately adjacent to and in contact with the inner surface of the catheter housing, the blade edge defining a rotational cutting direction essentially perpendicular to the blade edge and facing in the direction of rotation; and

an inner housing rotatably disposed within and immediately adjacent to the inner surface of the outer housing, the inner housing having an inner window means for invagination of conduit tissue through the outer window into the inner housing, the inner window means enclosing the blade edge, the inner window means further having a tissue ingress edge spaced apart from and parallel to the blade edge in the rotational cutting direction, the ingress edge located immediately adjacent to the inner surface of the outer housing, the distance between the blade edge and the spaced apart ingress edge being selected to limit the angular extent of tissue invaginated through the outer housing window into the inner housing between the ingress edge and the blade edge,

whereby the cutting means is adapted to remove a slice of tissue of a controlled thickness from within the biological conduit by rotating and translating the cutting means.

7. The cutter apparatus as set forth in claim 6, wherein the blade means has an arcuate concave interior surface projecting inward from the blade edge toward the interior of the inner housing for directing cut tissue into the inner housing.

8. The cutter apparatus as set forth in claim 6, wherein the distance between the blade edge and the spaced apart ingress edge is selected to limit the angular extent of tissue invaginated into the inner housing between the ingress edge and the blade edge to a value between 0°

and about 270°

.

9. The cutter apparatus as set forth in claim 6, wherein the distance between the blade edge and the spaced apart ingress edge is selected to limit the angular extent of tissue invaginated into the inner housing between the ingress edge and the blade edge to a value of about 20°

.

10. The cutter apparatus as set forth in claim 6, wherein the outer housing window includes:

a distal edge and a proximal edge

a parting edge between the distal edge and proximal edge, the parting edge being comprised of one or more contiguous submultiple edges of the length of the parting edge, each submultiple edge comprising a succession of one or more spiral cutting increments, the succession of spiral cutting increments forming a continuous line along each respective submultiple edge, beginning at one end of each submultiple edge, the spiral cutting increments of each submultiple edge terminating at the opposite end of each submultple edge, the spiral cutting increments of each submultiple edge being smoothly and continuously displaced in a circumferential direction defined by the rotation of the cutter means, each spiral increment of each submultiple edge having a cutting edge lying adjacent to the inner surface of the outer housing; and

the cutter means including a blade cutting edge lying immediately adjacent to the inner surface of the outer housing, the blade cutting edge defining a cutting direction facing in the direction of the parting edge and facing in the rotational cutting direction;

whereby the parting edge and the blade cutting edge cooperate for removing the slice of tissue from the biological conduit tissue by separating the slice from the conduit tissue by rotating and translating the blade cutting edge past the parting edge in the rotational cutting direction.

11. The cutter apparatus as set forth in claim 6, wherein the means for rotating the cutter means includes a rotational limit means for limiting the extent of a rotational cutting stroke of the cutter means to a preselected portion of one complete rotation, the means for limiting rotation having a first limit defining the beginning of a rotational cutting stroke wherein the cutter means is positioned prior to cutting tissue in contact with the housing window, the means for limiting rotation further having a second limit defining the end of the rotational cutting stroke wherein the cutter means is positioned after completing a cutting stroke past the housing window.

12. A cutter apparatus as set forth in claim 11, wherein:

the cutter means includes a rotatable cover means for closing the housing window, the cover means being interposed coaxially between a portion of the blade means and immediately adjacent to the inner surface of the outer housing, the cover means mounted in fixed rotatable relation with the blade means, the cover means being sized to entirely close the housing window when the blade means and cover means are rotated into a closed position,

whereby the tissue removed from the biological conduit will be entrapped within the housing when the housing window is closed by the cover means.