Atherectomy apparatus, systems, and methods
Described here are devices and methods for performing atherectomies. Generally, the atherectomy devices may comprise a handle, a cutter assembly, and a catheter or catheter assembly therebetween. The cutter assembly may include a cutter housing and a cutter comprising a first cutting element and a second cutting element, each of which may be rotated relative to the atherectomy device to cut occlusive material.
1. A device for removing occlusive material from a vessel comprising:
a catheter;
a cutter coupled to the catheter, the cutter having a rotational axis and comprising a cutting edge with a positive rake angle of at least 20 degrees;
wherein the rake angle is defined as an angle measured between (i) a radius drawn from the rotational axis to the cutting edge and (ii) a tangent drawn from an inner face of the cutting edge.
2. The device of claim 1 , wherein the positive rake angle is between 60 degrees and 80 degrees.
3. The device of claim 2 , wherein the positive rake angle is 70 degrees.
4. The device of claim 1 , wherein the cutting edge comprises a helical flute.
5. The device of claim 1 , wherein the cutter comprises a first cutting element and a second cutting element.
6. The device of claim 5 , wherein the first cutting element comprises at least one helical flute.
7. The device of claim 6 , wherein the cutter further comprises a second cutting element, and wherein the second cutting element comprises at least two helical flutes.
8. The device of claim 5 , wherein the first cutting element has at least a first portion having an outside diameter greater than or equal to an outside diameter of the cutter housing.
9. The device of claim 5 , wherein at least a portion of the first cutter element extends from an opening in the cutter housing.
10. The device of claim 9 , wherein the portion of the first cutter element extending from the opening in the cutter housing has a hemispherical profile.
11. The device of claim 9 , wherein the relief angle is about 0 degrees.
12. The device of claim 1 , wherein the cutting edge has a relief angle less than or equal to 10 degrees.
13. The device of claim 1 , wherein the cutting edge has a flute angle less than or equal to 30 degrees.
14. The device of claim 1 , wherein the cutting edge has a helix angle between 30 degrees and 60 degrees.
15. The device of claim 1 , wherein the device further comprises a cutter housing and the cutter is at least partially disposed within a cutter housing.
16. The device of claim 15 , wherein the cutter comprises a first cutting element and a second cutting element.
17. The device of claim 16 , wherein the first cutting element comprises at least one helical flute.
18. The device of claim 17 , wherein the cutter further comprises a second cutting element, and wherein the second cutting element comprises at least two helical flutes.