Atherectomy devices, systems, and methods
The devices and methods generally relate to treatment of occluded body lumens. In particular, the present devices and methods relate to removal of the occluding material from the blood vessels as well as other body lumens. In some variations, the methods comprise providing a vascular device comprising a catheter body, a cutter assembly, a drive mechanism, a torque shaft, and a deflecting mechanism. The methods may further comprise operating the drive mechanism to cut occlusive material, operating the deflecting mechanism to deflect the cutter assembly, and rotating the distal end of the catheter body to sweep the cutter assembly.
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 axial advancement in the body lumen, the catheter body having a center axis along which axial advancement occurs and including spaced apart proximal and distal ends,
a cutter assembly having an outside diameter attached at the distal end of the catheter body, the cutter assembly comprising a housing having at least one opening, a distal cutter having at least one helical cutting edge configured to rotate about the center axis relative to the housing to cut occlusive material at the distal end of the catheter body and convey the occlusive material from the body lumen proximally into the housing,
a drive mechanism at the proximal end of the catheter body;
a torque shaft coupled to the drive mechanism and extending through the catheter body and coupled to the cutter to rotate the cutter assembly about the center axis relative to the housing, and
a deflecting mechanism slidable within the catheter body in response to a force applied at the proximal end of the catheter body for deflecting the cutter assembly relative to the center axis of the catheter body to point the cutter assembly toward a side of the body lumen without necessitating axial advancement of the catheter body in the body lumen,
manipulating the proximal end of the catheter body to introduce the distal end of the catheter body into the body lumen toward occlusive material,
operating the drive mechanism to rotate the cutter assembly about the central axis to cut occlusive material at the distal end of the catheter body, to convey the occlusive material from the body lumen proximally into the housing,
operating the deflecting mechanism at the proximal end of the catheter body to deflect the cutter assembly relative to the center axis of the catheter body to point the cutter assembly toward a side of the body lumen without necessitating axial advancement of the catheter body in the body lumen, and
rotating the distal end of the catheter body when the cutter assembly is deflected to sweep the cutter assembly in an arc about the center axis to cut occlusive material in a region that is at least two times larger than the outside diameter of the cutter assembly, wherein rotating the distal end of the catheter body comprises operating a torque control mechanism separate from the deflecting mechanism to manually or automatically control the sweep of the cutter assembly.
2. A method according to claim 1
further including removing cut occlusive material through a lumen in the catheter body for discharge at the proximal end of the catheter body.
3. A method according to claim 1 :
wherein the region is at least three times larger than the outside diameter of the cutting assembly.
4. A method according to claim 1 :
wherein the region is at least four times larger than the outside diameter of the cutting assembly.
5. A method according to claim 1 :
wherein introducing the distal end of the catheter body into the body lumen includes introducing the distal end of the catheter body into the body lumen using an 8Fr or smaller introducer.
6. A method according to claim 1 :
wherein the vascular device further comprises a control knob, and
wherein the torque control mechanism and the deflecting mechanism are controlled by the control knob.