Atherectomy devices, systems, and methods
The devices and methods generally relate to treatment of occluded body lumens. In particular, the present devices and method relate to removal of the occluding material from the blood vessels as well as other body lumens.
1. A method for cutting and removing occlusive material from a body lumen, the method comprising:
providing a vascular device comprising
a catheter body sized and configured for advancement in the body lumen, the catheter body having a center axis and including spaced apart proximal and distal ends, the distal end of the catheter body including a tubular bending frame within the catheter body having a plurality of openings spaced along a radial side of the bending frame to provide reduced column strength along the radial side, the radial side facing a direction,
a cutter assembly attached to the distal end of the catheter body and having an outside diameter located at a distal end of the bending frame, the cutter assembly including a cutter rotatable about the center axis to cut occlusive material,
a drive mechanism at the proximal end of the catheter body and coupled to the cutter assembly to rotate the cutter,
a sweep member coupled to a proximal end of the bending frame within the catheter body wherein advancing the sweep member toward the distal end of the catheter body applies an axial force to compress the bending frame, thereby bending the bending frame and the distal end of the catheter body relative to the center axis in the direction of the radial side, wherein the bending frame is rotatable independently of the drive mechanism and of the catheter body,
advancing the cutter assembly within a body lumen toward occlusive material,
operating the drive mechanism to rotate the cutter about the center axis to cut the occlusive material,
advancing the sweep member to bend the bending frame and the distal end of the catheter body, and
rotating the bending frame while the bending frame is bent to sweep the cutter assembly in an arc about the center axis to cut occlusive material in a region larger than the outside diameter of the cutter assembly.
2. A method according to claim 1 further including conveying occlusive material from the cutting assembly for discharge.
3. A method according to claim 1 :
wherein advancing the cutter assembly within the body lumen includes introducing the catheter body into the body lumen using an 8 Fr or smaller introducer.
4. A method according to claim 1
wherein advancing the cutter assembly within the body lumen includes orienting the bending frame so the radial side is positioned in a direction of desired deflection at a bend in the body lumen, advancing the catheter in the body lumen into the bend, and, without operating the sweep member, allowing the catheter body to passively deflect when the cutter assembly contacts a bend in the body lumen in response to bending of the bending frame in the direction of the radial side.
5. A method according to claim 1
wherein the sweep member is also coupled to the bending frame to rotate the bending frame about the center axis, and
wherein rotating the bending frame includes operating the sweep member to rotate the bending frame.
6. A method according to claim 1
wherein advancing the cutter assembly within a body lumen includes passing the cutter assembly over a guide wire.
7. A method according to claim 1
wherein the openings include at least one slit.
8. A method according to claim 1
wherein the openings include at least one slot.
9. A method according to claim 1
wherein the sweep member comprises a cylindrical tube.