Atherectomy device including cutting blades with positive and negative rake angles

Abstract

A plaque removal device includes a catheter connected to a handle. The catheter includes an outer sheath and a drive shaft, which is carried in the outer sheath and can rotate relative to the outer sheath. The cutter assembly is connected to the outer sheath and extends distally relative to the outer sheath. The cutter assembly includes a housing connected to the outer sheath and extending distally from the outer sheath. The proximal cutting element is rotatably carried by the housing, and the proximal cutting element is connected to the drive shaft and extends distally from the drive shaft. The proximal cutting element includes at least one proximal cutting blade, and the at least one proximal cutting blade has a negative rake angle. The distal cutting element can rotate relative to the housing with the proximal cutting element. The distal cutting element includes at least one distal cutting blade, and the at least one distal cutting blade has a positive rake angle.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] none. Technical Field

[0003] The devices and methods described herein generally relate to the treatment of occluded body lumens, such as the removal of occlusive material from a blood vessel or other body site. Background Art

[0004] Peripheral and interventional cardiology is a medical specialty that deals with the treatment of various forms of cardiovascular disease, including coronary artery disease and peripheral vascular disease. Coronary artery disease and peripheral vascular disease can develop as a result of narrowing of the arteries caused by atherosclerosis (also known as hardening of the arteries). Coronary artery disease generally affects the arteries of the heart - the arteries that carry blood to the heart muscle and surrounding tissues. Peripheral vascular disease refers to various diseases of the vascular system outside the heart and brain (for example, which carries blood to the legs).

[0005] Atherosclerosis usually affects medium and large arteries and occurs when fat, cholesterol, and other substances build up on the artery walls and form fleshy or hard / calcified structures called plaques / lesions. When plaque builds up in the artery wall, the artery may narrow and become less flexible, which can make it more difficult for blood to flow through. In peripheral arteries, plaques are usually not localized but may extend along the axis of the artery by as much as 10 millimeters or more (and in some cases up to 400 millimeters or more).

[0006] Pieces of plaque may break off and travel through the affected artery to smaller blood vessels, where they may block smaller blood vessels in some cases and may cause tissue damage or tissue death (embolism). In some cases, atherosclerotic plaque may be associated with weakening of the wall of the affected artery, which may lead to an aneurysm. Minimally invasive surgery may be performed to remove plaque from the arteries in an effort to relieve or help avoid complications of atherosclerosis.

[0007] Some interventional surgical methods can be used to treat atherosclerosis. For example, in balloon angioplasty, a doctor can advance a deflated intravascular balloon catheter into a narrowed artery and can inflate the balloon to crush and / or displace the plaque against the vessel wall. A successful angioplasty can help reopen the artery and allow improved blood flow. Typically, balloon angioplasty is performed in conjunction with the placement of a stent or stent structure within the artery to help minimize restenosis of the artery. However, balloon angioplasty may stretch the artery and induce the formation of scar tissue, while stent placement may cut arterial tissue and also induce the formation of scar tissue. The formation of scar tissue may lead to restenosis of the artery. In some cases, balloon angioplasty may also tear the vessel wall.

[0008] Atherectomy is another treatment for atherosclerosis and involves the use of an intravascular device to mechanically remove (i.e., debulk) plaque from the artery wall. An atherectomy device can allow plaque to be removed from the artery wall, thereby reducing the risk of stretching, cutting, or dissecting the artery wall and causing tissue damage that can lead to restenosis. In some cases, atherectomy can be used to treat restenosis by removing scar tissue.

[0009] Unfortunately, some atherectomy devices are limited in structure and performance. For example, the cutting elements or components of some atherectomy devices cannot adequately treat total occlusions. Therefore, it is desirable to provide improved atherectomy devices and methods. Summary of the invention

[0010] The present disclosure proposes a plaque removal device. The plaque removal device includes a handle configured to be manipulated by a user. A catheter is connected to the handle. The catheter includes an outer sheath and a drive shaft, wherein the drive shaft is disposed in the outer sheath and can rotate relative to the outer sheath. The cutter assembly is connected to the outer sheath and extends distally relative to the outer sheath. The cutter assembly includes a housing connected to the outer sheath and extending distally from the outer sheath. The proximal cutting element is rotatably carried by the housing, and the proximal cutting element is connected to the drive shaft and extends distally from the drive shaft. The proximal cutting element includes at least one proximal cutting blade, and the at least one proximal cutting blade has a negative rake angle. The distal cutting element can rotate relative to the housing together with the proximal cutting element. The distal cutting element includes at least one distal cutting blade, and the at least one distal cutting blade has a positive rake angle.

[0011] The arteriotomy device according to the preceding paragraph, wherein the proximal cutting element comprises a plurality of proximal cutting blades, each of the plurality of proximal cutting blades having a negative rake angle.

[0012] The atherectomy device of any preceding paragraph, wherein the distal cutting element comprises a plurality of distal cutting blades, each of the plurality of distal cutting blades having a positive rake angle.

[0013] An atherectomy device according to any of the preceding paragraphs, wherein the negative rake angle is in the range of 8 degrees to 24 degrees.

[0014] An atherectomy device according to any of the preceding paragraphs, wherein the negative rake angle is substantially 16 degrees.

[0015] An atherectomy device according to any of the preceding paragraphs, wherein the positive rake angle is in the range of 40 degrees to 70 degrees.

[0016] An atherectomy device according to any of the preceding paragraphs, wherein the positive rake angle is substantially 55 degrees.

[0017] The present disclosure also proposes a plaque removal device. The plaque removal device includes a handle configured to be manipulated by a user. A catheter is connected to the handle. The catheter includes an outer sheath and a drive shaft, wherein the drive shaft is disposed in the outer sheath and can rotate relative to the outer sheath. The cutter assembly is connected to the outer sheath and extends distally relative to the outer sheath. The cutter assembly includes a shell connected to the outer sheath and extending distally from the outer sheath. The proximal cutting element is rotatably carried by the shell around the rotation axis along the rotation direction. The proximal cutting element is connected to the drive shaft and extends distally from the drive shaft. The proximal cutting element is carried by the shell, and the proximal cutting element is configured to cut occlusive material when rotating relative to the shell around the rotation axis along the rotation direction. The proximal cutting element is connected to the drive shaft and extends distally from the drive shaft. The proximal cutting element includes at least one proximal cutting blade. The at least one proximal cutting blade has a first rake angle, and the first rake angle extends from (i) a radius from the rotation axis to the radially farthest edge of the at least one proximal cutting blade to (ii) a tangent to the inner surface of the at least one proximal cutting blade at the radially farthest edge. The first rake angle is in a direction opposite to the direction of rotation. The distal cutting element is connected to the proximal cutting element. The distal cutting element is configured to cut occlusive material when it rotates relative to the housing around the rotation axis along the rotation direction with the proximal cutting element. The distal cutting element includes at least one distal cutting blade. The at least one distal cutting blade has a second rake angle, and the second rake angle extends from (iii) a radius from the rotation axis to the radially farthest edge of the at least one distal cutting blade to (iv) a tangent to the inner surface of the at least one distal cutting blade at the radially farthest edge of the at least one distal cutting blade. The second rake angle is in the same direction as the direction of rotation.

[0018] The arteriotomy device according to the preceding paragraph, wherein the proximal cutting element includes a plurality of proximal cutting blades, each of the plurality of proximal cutting blades having a first rake angle.

[0019] The atherectomy device of any preceding paragraph, wherein the distal cutting element comprises a plurality of distal cutting blades, each of the plurality of distal cutting blades having a second rake angle.

[0020] An atherectomy device according to any of the preceding paragraphs, wherein the first rake angle is in the range of 8 degrees to 24 degrees.

[0021] An atherectomy device according to any of the preceding paragraphs, wherein the first rake angle is substantially 16 degrees.

[0022] An atherectomy device according to any of the preceding paragraphs, wherein the second rake angle is in the range of 40 degrees to 70 degrees.

[0023] An atherectomy device according to any of the preceding paragraphs, wherein the second rake angle is substantially 55 degrees.

[0024] The atherectomy device of any preceding paragraph, wherein the housing comprises an inner surface, and the inner surface comprises at least one shearing element.

[0025] An atherectomy device according to any of the preceding paragraphs, wherein the inner surface comprises a plurality of shearing elements.

[0026] The atherectomy device of any preceding paragraph, wherein at least one shearing element comprises a channel.

[0027] The phrases "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctive and disjunctive in use. For example, each of the expressions "at least one of A, B, and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", and "A, B, and / or C" refers to A alone, B alone, C alone, A and B together, A and C together, B and C together, and A, B, and C together. When each of A, B, and C in the above expressions refers to an element (e.g., X, Y, and Z) or a class of elements (e.g., X1-X n 、Y1-Y m and Z1-Z o ), the phrase is intended to refer to a single element selected from X, Y, and Z, or a combination of elements selected from the same category (e.g., X1 and X2), or a combination of elements selected from two or more categories (e.g., Y1 and Z o ).

[0028] The term "a" or "an" entity refers to one or more of that entity. Therefore, the terms "a" (or "an"), "one or more" and "at least one" can be used interchangeably herein. It should also be noted that the terms "includes," "comprising," and "having" can be used interchangeably. It should also be noted that the terms "includes," "comprising," and "having" can be used interchangeably.

[0029] As used herein, the term "means" should be given the broadest possible interpretation in accordance with 35 U.S.C. Section 112(f). Therefore, a claim containing the term "means" should cover all structures, materials, or actions described herein, and all equivalents thereof. In addition, the structures, materials, or actions and their equivalents should include all contents described in the Summary of the Invention, the Description of the Figures, the Detailed Description, the Abstract, and the Claims.

[0030] It should be understood that each maximum numerical limitation given throughout this disclosure is considered to include each and every lower numerical limitation as an alternative, as if these lower numerical limitations are expressly written herein. Each minimum numerical limitation given throughout this disclosure is considered to include each and every larger numerical limitation as an alternative, as if these larger numerical limitations are expressly written herein. Each numerical range given in this disclosure is considered to include each and every narrower numerical range that falls within the wider numerical range, as if these narrower numerical ranges are expressly written herein.

[0031] The foregoing is a simplified summary of the present disclosure to provide an understanding of some aspects of the present disclosure. The summary is neither a broad nor an exhaustive overview of the present disclosure and its various aspects, embodiments, and configurations. It is neither intended to identify the key or important elements of the present disclosure nor to describe the scope of the present disclosure, but rather to present selected concepts of the present disclosure in a simplified form as an introduction to the more detailed description given below. As will be appreciated, other aspects, embodiments, and configurations of the present disclosure may utilize one or more features described above or described in detail below, alone or in combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present disclosure. These drawings, together with the description, explain the principles of the present disclosure. The accompanying drawings simply illustrate preferred and alternative examples of how to make and use the present disclosure, and should not be interpreted as limiting the present disclosure to only the examples shown and described. As shown in the drawings referenced below, other features and advantages will become apparent from the following more detailed description of various aspects, embodiments and configurations of the present disclosure.

[0033] Figure 1 is a side view of a plaque removal system according to an embodiment of the present disclosure.

[0034] Figure 2A yes Figure 1 Detailed side view of the distal portion of the atherectomy system.

[0035] Figure 2B yes Figure 1 Detailed perspective view of the distal portion of the atherectomy system.

[0036] Figure 2C yes Figure 2A Detailed transverse cross-sectional view of the distal portion of the atherectomy system.

[0037] Figure 3A yes Figure 1 Perspective view of the distal cutting element of an atherectomy system.

[0038] Figure 3Byes Figure 3A Side view of the distal cutting element.

[0039] Figure 3C is along Figure 3B A cross-sectional view of the distal cutting element taken along line 3C-3C.

[0040] Figure 4A yes Figure 1 Perspective view of the proximal cutting element of an atherectomy system.

[0041] Figure 4B yes Figure 4A Front view of the proximal cutting element.

[0042] Figure 5A yes Figure 1 Perspective view of the cutter housing of an atherectomy system.

[0043] Figure 5B yes Figure 5A Front view of the cutter housing.

[0044] It should be understood that the drawings are not necessarily drawn to scale. In some cases, details that are not necessary for understanding the present disclosure or that make other details difficult to understand may be omitted. Of course, it should be understood that the present disclosure is not necessarily limited to the specific embodiments shown herein. DETAILED DESCRIPTION

[0045] Before explaining any embodiments of the present disclosure in detail, it should be understood that the application of the present disclosure is not limited to the details of the construction and component arrangement set forth in the following description or shown in the following drawings. The present disclosure is capable of other embodiments and can be practiced or implemented in various ways. In addition, it should be understood that the words and terms used herein are for descriptive purposes and should not be considered limiting. The words "including", "comprising" or "having" and their variations used herein are intended to cover the items listed thereafter and their equivalents as well as additional items.

[0046] The present disclosure generally relates to devices, systems, and methods for mechanical atherectomy. Figure 1 , showing an exemplary embodiment of the plaque removal system described herein. The plaque removal system 100 includes an intravascular plaque removal device 102 and a guide wire 104, on which the plaque removal device 102 can be arranged. In some embodiments, the guide wire 104 is silicon-coated or uncoated (bare), or otherwise does not contain a PTFE coating. The plaque removal system according to some embodiments of the present disclosure includes a guide wire 104 including a PTFE coating, or the plaque removal system according to some embodiments of the present disclosure lacks a guide wire 104.

[0047] Continue to refer Figure 1, the plaque removal device 102 generally includes a handle 106 and a catheter 108. The handle 106 is configured to be grasped and manipulated by a user (e.g., a medical professional) during the plaque removal operation. The catheter 108 is connected to the handle 106 and extends distally relative to the handle 106. The catheter 108 is configured to be positioned in a blood vessel of a subject (e.g., a patient) during the plaque removal operation to facilitate the removal of occlusive materials (e.g., plaque) therefrom. In some embodiments and as shown in the figure, the distal portion 110 of the catheter 108 has an arc shape or configuration. In some embodiments, the distal portion 110 of the catheter 108 normally has an arc configuration ("normally" is understood to mean that the catheter 108 is not subjected to any external contact force due to, for example, contact with the vessel wall), and can be deflected to other configurations. In other embodiments, the distal portion 110 of the catheter 108 normally has a straight shape or configuration, and can be deflected to other configurations. In some embodiments, the catheter 108 can be selectively rotated about the rotation axis 112 of the catheter 108 relative to the handle 106 to facilitate proper positioning and / or "sweeping" of the distal portion 110 of the catheter 108 during the plaque removal operation. In some embodiments and as shown, the handle 106 carries a rotatable knob or dial 114 for selectively rotating the catheter 108 relative to the handle 106. The catheter 108 includes an outer sheath 116, which is coupled to a cutter assembly 118, and the cutter assembly 118 extends distally from the outer sheath 116. The cutter assembly 118 will be described in further detail below.

[0048] Figure 2A-2C The distal portion 110 of the catheter 108 is shown, which includes, among other components, an outer sheath 116 and a cutter assembly 118. The cutter assembly 118 includes a collar 200 that is coupled to the outer sheath 116 and extends distally from the outer sheath. The cutter assembly 118 also includes a housing 202 that is coupled to the collar 200 and extends distally from the collar. The housing 202 rotatably carries a cutting element. Specific reference Figure 2B-2C , the housing 202 rotatably carries a first or distal cutting element 204 and a second or proximal cutting element 206. Rotation of the first and second cutting elements 204, 206 relative to the housing 202 in a rotational direction 209 about a rotational axis 208 causes the cutting elements 204, 206 to cut occlusive material and transport the occlusive material into the housing 202 (a process also referred to as "debulking").

[0049] Still reference Figure 2B-2C , the first cutting element 204 generally extends distally from the second cutting element 206 and the housing 202. The first cutting element 204 includes a central opening 210 (see Figure 2C) for coupling with the second cutting element 206. The second cutting element 206 is generally disposed within the housing 202, and in some embodiments and as shown, can be completely disposed within the housing 202. The second cutting element 206 is also generally disposed proximal to the first cutting element 204, although the second cutting element 206 includes a shaft or rod 212 that is received in the central opening 210. The rod 212 can be coupled to the first cutting element 204 in a variety of ways. For example, the rod 212 can be coupled to the first cutting element 204 by welding. In some embodiments and as shown, the rod 212 extends distally relative to the first cutting element 204. The rod 212 includes an inner lumen 214 for receiving a guide wire (shown elsewhere).

[0050] Specific reference Figure 2C , the atherectomy device 102 also includes a rotatable drive shaft 216 that couples the first cutting element 204 and the second cutting element 206 to a prime mover (e.g., a motor carried by the handle 106--not shown). That is, the prime mover rotates the drive shaft 216, which in turn rotates the first cutting element 204 and the second cutting element 206 to facilitate cutting and transporting the occlusive material into the housing 202. In some embodiments, the cutter assembly 118 captures the cut occlusive material from the blood without using vacuum suction. In other embodiments, vacuum suction can help capture the cut occlusive material.

[0051] Continue to refer Figure 2C In some embodiments, the atherectomy device 102 further includes an internal conveyor 218 that is coupled to the drive shaft 216 and rotates with the drive shaft 216. When the occlusive material is delivered into the cutter housing 202 by the first cutting element 204 and the second cutting element 206, the conveyor 218 moves the cut occlusive material proximally through the catheter 108 so as to be discharged to the outside of the subject's body. In some embodiments, this delivery can occur without the assistance of vacuum suction. In other embodiments, vacuum suction can help deliver the cut occlusive material.

[0052] Reference now Figures 3A-3C , the first cutting element 204 includes one or more first or distal cutting grooves or blades 300 that extend distally relative to the housing 202. In some embodiments and as shown, the first cutting element 204 includes two cutting blades 300. In some embodiments and as shown, one or more of the first cutting blades 300 extend helically relative to the rotation axis 208 of the first cutting element 204 and the second cutting element 206. In some embodiments and with specific reference to Figure 3C, one or more of the first cutting blades 300 have a positive rake angle 302. That is, one or more of the first cutting blades 300 have a rake angle 302 measured between an imaginary radius 304 extending from the rotation axis 208 of the first cutting element 204 to the radially farthest edge 306 of the cutting blade 300 and a tangent line 308 tangent to the inner surface 310 of the cutting blade 300 at the radially farthest edge 306. The direction of the rake angle 302 is the same as the rotation direction 209 of the first cutting element 204 and the second cutting element 206 about the rotation axis 208. In some embodiments, the rake angle 302 is in the range of 30 degrees to 80 degrees. In some embodiments, the rake angle 302 is in the range of 35 degrees to 75 degrees. In some embodiments, the rake angle 302 is in the range of 40 degrees to 70 degrees. In some embodiments, the rake angle 302 is in the range of 45 degrees to 65 degrees. In some embodiments, the rake angle 302 is in the range of 50 degrees to 60 degrees. In some embodiments, the rake angle 302 is substantially 55 degrees (ie, 55 degrees ± 2.5 degrees).

[0053] Reference now Figure 4A-4B , the second cutting element 206 includes one or more second or proximal cutting grooves or blades 400. In some embodiments, the second cutting element 206 has twice as many blades 400 as the first cutting element 204. In some embodiments and as shown, the second cutting element 206 includes four cutting blades 400. In some embodiments and as shown, one or more of the second cutting blades 400 extend helically relative to the rotation axis 208 of the first cutting element 204 and the second cutting element 206. In some embodiments and with specific reference to Figure 4B, one or more of the second cutting blades 400 have a negative rake angle 402. Explained in another way, one or more of the second cutting blades 400 have a rake angle 402, which is measured between an imaginary radius 404 extending from the rotation axis 208 of the second cutting element to the radially farthest edge 406 of the cutting blade 400 and a tangent 408 tangent to the inner surface 410 of the cutting blade 400 at the radially farthest edge 406. The direction of the rake angle 402 is opposite to the rotation direction 209 of the first cutting element 204 and the second cutting element 206 around the rotation axis 208. Explained in another way, the inner face 410 of one or more of the second cutting blades 400 can be tilted outward or forward from the cutting edge. In some embodiments, the rake angle 402 is in the range of 5 degrees to 45 degrees (also referred to as -5 degrees to -45 degrees). In some embodiments, the rake angle 402 is in the range of 6 degrees to 35 degrees (also referred to as -6 degrees to -35 degrees). In some embodiments, the rake angle 402 is in the range of 8 to 24 degrees (also referred to as -8 to -24 degrees). In some embodiments, the rake angle 402 is substantially 16 degrees (ie, 16 degrees ± 2.5 degrees; also referred to as substantially -16 degrees (ie, -16 degrees ± 2.5 degrees)).

[0054] In some embodiments, the positive rake angle 302 of the first cutting element 204 and the negative rake angle 402 of the second cutting element 206 facilitate improving cutting efficiency and / or inhibiting the clogging of occlusive material in the housing 202. More specifically, in some embodiments, the positive rake angle 302 of the first cutting element 204 facilitates cutting and conveying occlusive material toward the second cutting element 206, while the negative rake angle 402 of the second cutting element 206 facilitates moving the occlusive material radially outward and proximally toward the housing 202, thereby inhibiting the clogging of occlusive material in the housing 202.

[0055] Figure 5A-5BThe housing 202 of the cutter assembly 118 is shown. In some embodiments and as shown, the inner surface 500 of the housing 202 includes one or more shearing elements 502, which further shred the occlusive material. In some embodiments and as shown, the housing 202 includes five shearing elements 502. In other embodiments, the housing 202 includes a different number of shearing elements 502 (e.g., one, two, three, four, six, seven, eight, nine, ten or more shearing elements 502). In some embodiments, the shearing element 502 is a negative feature (e.g., a channel formed on the inner surface 500 of the housing 202, as shown). In some embodiments, the shearing element 502 is a positive feature (e.g., a ridge or protrusion extending from the inner surface 500 of the housing 202). In some embodiments and as shown, the shearing element 502 extends in a direction substantially parallel to the axis of rotation 208 (shown elsewhere-i.e., parallel ±10 degrees). In some embodiments, one or more of the shearing elements 502 do not extend in a direction substantially parallel to the rotation axis 208 (eg, one or more of the shearing elements 502 may extend helically relative to the rotation axis 208 ).

[0056] The foregoing discussion has been presented for the purpose of illustration and description. The foregoing is not intended to limit the present disclosure to one or more forms disclosed herein. For example, in the preceding summary of the invention, various features of the present disclosure are combined together in one or more aspects, embodiments and / or configurations for the purpose of simplifying the present disclosure. The features of the aspects, embodiments and / or configurations of the present disclosure may be combined in alternative aspects, embodiments and / or configurations different from those discussed above. This disclosure method should not be interpreted as reflecting the intention that the claims require more features than the features explicitly stated in each claim. On the contrary, as reflected in the following claims, the creative aspects lie in less than all the features of a single aforementioned disclosed aspect, embodiment and / or configuration. Therefore, the following claims are incorporated herein into the specific embodiments, and each claim is independently a separate preferred embodiment of the present disclosure.

[0057] In addition, although the description has included descriptions of one or more aspects, embodiments and / or configurations and certain variations and modifications, other variations, combinations and modifications are also within the scope of the present disclosure, for example, within the skill and knowledge of those skilled in the art after understanding the present disclosure. It is intended to obtain rights including alternative aspects, embodiments and / or configurations within the permitted scope, including alternative, interchangeable and / or equivalent structures, functions, scopes or steps to the claimed protection, regardless of whether such alternative, interchangeable and / or or equivalent structures, functions, scopes or steps are disclosed herein, and it is not intended to publicly dedicate any patentable subject matter.

Claims

1. A plaque removal device, comprising: a handle configured to be manipulated by a user; a catheter coupled to the handle, the catheter comprising an outer sheath and a drive shaft, wherein the drive shaft is disposed within the outer sheath and is rotatable relative to the outer sheath; as well as a cutter assembly coupled to the outer sheath and extending distally relative to the outer sheath, the cutter assembly comprising: a housing coupled to the outer sheath and extending distally from the outer sheath; a proximal cutting element rotatably carried by the housing, the proximal cutting element coupled to the drive shaft and extending distally from the drive shaft, the proximal cutting element including at least one proximal cutting blade having a negative rake angle configured to facilitate moving occlusive material radially outward and proximally toward the housing; and a distal cutting element rotatable relative to the housing with the proximal cutting element, the distal cutting element comprising at least one distal cutting blade having a positive rake angle configured to facilitate cutting of occlusive material and transport of the occlusive material toward the proximal cutting element; Wherein, the shell includes an inner surface, and the inner surface includes at least one shearing element.

2. The atherectomy device according to claim 1, wherein: The proximal cutting element includes a plurality of proximal cutting blades, each of the plurality of proximal cutting blades having the negative rake angle.

3. The atherectomy device according to claim 2, wherein: The distal cutting element includes a plurality of distal cutting blades, each of the plurality of distal cutting blades having the positive rake angle.

4. The atherectomy device according to claim 1, wherein: The distal cutting element includes a plurality of distal cutting blades, each of the plurality of distal cutting blades having the positive rake angle.

5. The atherectomy device according to claim 1, wherein: The negative rake angle is in the range of 8 degrees to 24 degrees.

6. The atherectomy device according to claim 5, wherein: The negative rake angle is 16 degrees.

7. The atherectomy device according to claim 1, wherein: The positive rake angle is in the range of 40 degrees to 70 degrees.

8. The atherectomy device according to claim 7, wherein: The positive rake angle is 55 degrees.

9. The atherectomy device according to claim 1, wherein: The negative rake angle is a first rake angle extending from (i) a radius from the rotational axis of the proximal cutting element to a radially distal-most edge of the at least one proximal cutting blade to (ii) a tangent line tangent to an inner surface of the at least one proximal cutting blade at the radially distal-most edge, the first rake angle being in a direction opposite to a rotational direction of the proximal cutting element; The distal cutting element is coupled to the proximal cutting element; The positive rake angle is a second rake angle extending from (iii) a radius from the rotation axis to the radially farthest edge of the at least one distal cutting blade to (iv) a tangent to the inner surface of the at least one distal cutting blade at the radially farthest edge, the second rake angle being in the same direction as the rotation direction.

10. The atherectomy device according to claim 9, wherein: The proximal cutting element includes a plurality of proximal cutting blades, each of the plurality of proximal cutting blades having the first rake angle.

11. The atherectomy device according to claim 10, wherein: The distal cutting element includes a plurality of distal cutting blades, each of the plurality of distal cutting blades having the second rake angle.

12. The atherectomy device according to claim 9, wherein: The distal cutting element includes a plurality of distal cutting blades, each of the plurality of distal cutting blades having the second rake angle.

13. The atherectomy device according to claim 1, wherein: The inner surface includes a plurality of shear elements.

14. The atherectomy device according to claim 1, wherein: The at least one shearing element comprises a channel.

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