Atherectomy device including axially oscillating a cutting element - Patents.com

Abstract

The atherectomy device includes a cutter assembly. The cutter assembly includes a housing, the housing including a housing bearing surface. The cutter assembly further includes a cutting element rotatably and translatably held by the housing. The cutting element includes at least one cutting blade configured to cut the occlusive material upon rotation of the cutting element relative to the housing. The cutting element further includes a cutter bearing surface configured to engage the housing bearing surface. When the cutting element rotates relative to the housing and the at least one cutting blade cuts the occlusive material, the cutting element translates distally relative to the housing until the cutter bearing surface engages the housing bearing surface.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE

[0001] The devices and methods described herein relate generally to the treatment of occluded body lumens, such as the removal of occluding material from a blood vessel or other body site. [Background technology]

[0002]

[0002] Peripheral and interventional cardiology is a medical specialty related to the treatment of various forms of cardiovascular disease, including coronary artery disease and peripheral vascular disease. Coronary artery disease and peripheral vascular disease can occur due to narrowing of the arteries due to atherosclerosis (also called arteriosclerosis). Coronary artery disease generally affects the arteries of the heart 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, those that carry blood to the legs.

[0003]

[0003] Atherosclerosis usually affects medium and large arteries and occurs when fats, cholesterol, and other substances grow in the arterial wall and form fleshy or hard / calcified structures called plaques / lesions. As plaques form in the arterial wall, the artery becomes narrower and less flexible, which makes it more difficult for blood to flow through the artery. In peripheral arteries, plaques are typically not localized and can extend longitudinally along the axis of the artery for as much as 10 mm or more (in some cases, up to 400 mm or more).

[0004]

[0004] Part of the plaque may break off and travel through the affected artery to smaller blood vessels, where such plaque may in some cases occlude the smaller blood vessels, resulting in tissue damage or tissue necrosis (embolization). In some cases, atherosclerotic plaque is associated with a weakening of the wall of the affected artery that may lead to an aneurysm. Minimally invasive procedures are performed to remove plaque from the artery to help reduce or prevent complications of atherosclerosis.

[0005]

[0005] Many interventional surgical procedures are used to treat atherosclerosis. In balloon angioplasty, for example, a physician advances a collapsed intravascular balloon catheter into a stenosed artery and inflates the balloon to macerate the plaque and / or move it against the vessel wall. Successful angioplasty helps reopen the artery, allowing improved blood flow. In many cases, balloon angioplasty is performed in combination with the placement of a stent or scaffolding structure in the artery to help minimize restenosis of the artery. However, balloon angioplasty may stretch the artery and induce scar tissue formation, while the placement of a stent may cut the arterial tissue and even induce scar tissue formation. Scar tissue formation leads to restenosis of the artery. In some instances, balloon angioplasty may also tear the vessel wall.

[0006]

[0006] Atherectomy is another treatment approach for atherosclerosis and involves the use of intravascular devices to mechanically remove (i.e., ablate) plaque from the wall of an artery. Atherectomy devices allow for the removal of plaque from the wall of an artery, reducing the risk of stretching, cutting, or severing the arterial wall and causing tissue damage that leads to restenosis. In some instances, atherectomy is used to treat restenosis by removing scar tissue. Summary of the Invention [Problem to be solved by the invention]

[0007]

[0007] Unfortunately, some atherectomy devices suffer from structural and performance limitations. For example, the cutting elements or assemblies of some atherectomy devices are unable to adequately treat total occlusions. Therefore, it would be desirable to provide improved atherectomy devices and methods. [Means for solving the problem]

[0008]

[0008] The present disclosure provides an atherectomy device. The atherectomy device includes a handle configured to be operated by a user. A catheter is coupled to the handle. The catheter includes an outer sheath and a drive shaft, the drive shaft being located within and rotatable relative to the outer sheath. The cutter assembly includes a housing coupled to and extending distally from the outer sheath, the housing including a housing bearing surface. The cutter assembly further includes a cutting element rotatably and translationally held by the housing. The cutting element is coupled to and extends distally from the drive shaft. The cutting element includes at least one cutting blade configured to cut the occlusion material upon rotation of the cutting element relative to the housing. The cutting element further includes a cutter bearing surface configured to engage the housing bearing surface. When the cutting element rotates relative to the housing and the at least one cutting blade cuts the occlusion material, the cutting element translates distally relative to the housing until the cutter bearing surface engages the housing bearing surface.

[0009]

[0009] The atherectomy device described in the preceding paragraph, wherein when the cutting element translates distally relative to the housing, the drive shaft extends axially, and when the cutter bearing surface engages the housing bearing surface, the drive shaft shortens axially, causing the cutting element to translate proximally relative to the housing.

[0010]

[0010] An atherectomy device as described in any one of the preceding paragraphs, wherein the cutter assembly further comprises a ferrule coupled to the housing, and when the cutter bearing surface engages the housing bearing surface, the drive shaft shortens axially, translating the cutting element in a proximal direction relative to the housing so that the cutting element engages the ferrule.

[0011]

[0011] The atherectomy device of any one of the preceding paragraphs, wherein the cutting element is translatable relative to the housing over a distance of 0.010 inches to 0.035 inches.

[0012]

[0012] The atherectomy device of any one of the preceding paragraphs, wherein the cutting element is translatable relative to the housing over a distance of 0.015 inches to 0.030 inches.

[0013]

[0013] An atherectomy device as described in any one of the preceding paragraphs, wherein the cutting element is a proximal cutting element, the cutter assembly further comprises a distal cutting element, the distal cutting element is coupled to the proximal cutting element and is rotatable together with the proximal cutting element relative to the housing, and the distal cutting element comprises at least one cutting blade.

[0014]

[0014] An atherectomy device as described in any one of the preceding paragraphs, wherein the cutter bearing surface is located between the distal and proximal ends of at least one cutting blade.

[0015]

[0015] The present disclosure further presents an atherectomy device. The atherectomy device includes a handle configured to be operated by a user. A catheter is coupled to the handle. The catheter includes an outer sheath and a drive shaft, the drive shaft being located within and rotatable relative to the outer sheath. The cutter assembly includes a housing coupled to and extending distally from the outer sheath, the housing including a cutter translation chamber. The cutter assembly further includes a cutting element rotatably and translationally held by the housing. The cutting element is coupled to and extends distally from the drive shaft. The cutting element includes at least one cutting blade configured to cut the occlusion material upon rotation of the cutting element relative to the housing. The cutting element further includes a cutter limiter rotatably received in the cutter translation chamber and translatable from a first position to a second position and back within the cutter translation chamber. When the cutting element rotates relative to the housing and the at least one cutting blade cuts the occluding material, the cutter limiter rotates and translates within the cutter translation chamber from a first position to a second position and the cutting element translates distally relative to the housing, and when the cutter limiter reaches the second position, the cutter limiter translates from the second position to the first position and the cutting element translates proximally relative to the housing.

[0016]

[0016] The atherectomy device described in the preceding paragraph, wherein when the cutting element translates distally relative to the housing, the drive shaft extends axially, and when the cutter limiter reaches a second position, the drive shaft shortens axially, causing the cutting element to translate proximally relative to the housing.

[0017]

[0017] An atherectomy device as described in any one of the preceding paragraphs, wherein when the cutter limiting portion translates from the first position to the second position, the cutting element translates relative to the housing over a distance of 0.010 inches to 0.035 inches.

[0018]

[0018] An atherectomy device as described in any one of the preceding paragraphs, wherein when the cutter limiting portion translates from the first position to the second position, the cutting element translates relative to the housing over a distance of 0.015 inches to 0.030 inches.

[0019]

[0019] An atherectomy device as described in any one of the preceding paragraphs, wherein the cutting element is a proximal cutting element, the cutter assembly further comprises a distal cutting element, the distal cutting element is coupled to the proximal cutting element and is rotatable together with the proximal cutting element relative to the housing, and the distal cutting element comprises at least one cutting blade.

[0020]

[0020] The expressions "at least one," "one or more," and "and / or" are non-exclusive expressions that are both conjunctive and disjunctive in logic. For example, 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" each mean A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C. Each of A, B, and C in the above expressions can represent elements such as X, Y, and Z, or elements such as X1 to X2. n , Y1~Y m , and Z1 to Z o When representing a set of elements such as X, Y, and Z, the expression can refer to a single element selected from X, Y, and Z, a combination of elements selected from the same set (e.g., X1 and X2), and a combination of elements selected from two or more sets (e.g., Y1 and Z). o) is intended to represent a combination of elements selected from

[0021]

[0021] A reference to an entity refers to one or more of that entity. Thus, the terms "a," "one or more," and "at least one" may be used interchangeably herein. It should also be noted that the terms "comprising," "including," and "having" may be used interchangeably.

[0022]

[0022] The term "means" as used herein is to be given its broadest possible interpretation in accordance with 35 U.S.C. 112(f). Accordingly, any claim containing the term "means" is intended to encompass all structures, materials, or acts described herein, and all equivalents thereof. Furthermore, the structures, materials, or acts, and their equivalents are intended to encompass all structures, materials, or acts described in the Summary, Brief Description of the Drawings, Detailed Description, Abstract, and the claims themselves.

[0023]

[0023] It should be understood that each maximum numerical limitation given throughout this disclosure is intended to include each lower numerical limitation as an alternative, as if such lower numerical limitation were expressly written herein. Each minimum numerical limitation given throughout this disclosure is intended to include each higher numerical limitation as an alternative, as if such higher numerical limitations were expressly written herein. Each numerical range given throughout this disclosure is intended to include each such narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

[0024]

[0024] The foregoing is a simplified summary of the present disclosure to provide an understanding of some aspects of the present disclosure. This summary is not an extensive or exhaustive overview of the present disclosure and its various aspects, embodiments, and configurations. It is not intended to identify key or critical elements of the present disclosure, nor is it intended to represent the scope of the present disclosure, but rather to present selected concepts of the present disclosure in a simplified form as a prelude to the more detailed description presented below. As will be appreciated, other aspects, embodiments, and configurations of the present disclosure are possible using one or more of the features described above or described in detail below, either alone or in combination.

[0025]

[0025] The accompanying drawings are incorporated into and form a part of this specification to illustrate some examples of the present disclosure. These drawings, together with the description, explain the principles of the present disclosure. The drawings merely illustrate preferred and alternative examples of how the present disclosure can be made and used, and are not to be construed as limiting the present disclosure to only the examples shown and described. Further features and advantages will become apparent from the following more detailed description of the various aspects, embodiments, and configurations of the present disclosure, as illustrated in the drawings referenced below. [Brief description of the drawings]

[0026] [Figure 1]

[0026] FIG. 1 is a side view of an atherectomy system according to an embodiment of the present disclosure. [Figure 2A]

[0027] FIG. 2 is a detailed side view of the distal portion of the atherectomy system of FIG. 1. [Figure 2B]

[0028] FIG. 2 is a detailed perspective view of a distal portion of the atherectomy system of FIG. 1. [Figure 2C]

[0029] FIG. 2B is a detailed cross-sectional view of a distal portion of the atherectomy system of FIG. 2A. [Figure 3A]

[0030] 2B is a detailed side view of a distal portion of the atherectomy system of FIG. 2A with the housing shown in hidden lines and the cutting element shown in a first position relative to the housing. [Figure 3B]

[0031] 2B is a detailed side view of a distal portion of the atherectomy system of FIG. 2A with the housing shown in hidden lines and the cutting element shown in a second position relative to the housing. [Figure 4A]

[0032] FIG. 2 is a perspective view of a distal cutting element of the atherectomy system of FIG. 1. [Figure 4B]

[0033] FIG. 4B is a side view of the distal cutting element of FIG. 4A. [Figure 4C]

[0034] FIG. 4C is a cross-sectional view of the distal cutting element taken along line 4C-4C of FIG. 4B. [Figure 5A]

[0035] FIG. 2 is a perspective view of a proximal cutting element of the atherectomy system of FIG. 1. [Figure 5B]

[0036] FIG. 5B is a front view of the proximal cutting element of FIG. 5A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027]

[0037] It should be understood that the figures are not necessarily to scale. In certain instances, details that are not necessary for understanding the disclosure or that represent other details that are difficult to perceive may be omitted. It should of course be understood that the disclosure is not limited to the specific embodiments shown in this specification.

[0028]

[0038] Before any embodiment of the present disclosure is described in detail, it is to be understood that the disclosure is not limited in its application to the detailed construction and arrangement of components set forth in the following description or illustrated in the following drawings. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways. It is further understood that the terms and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "comprising," "including," or "having," and variations thereof, herein means the inclusion of the items listed thereafter, and equivalents thereof, as well as additional items.

[0029]

[0039] The present disclosure relates generally to devices, systems, and methods for mechanical atherectomy. Referring to FIG. 1, an exemplary embodiment of an atherectomy system as described herein is shown. The atherectomy system 100 includes an intravascular atherectomy device 102 and a guidewire 104 over which the atherectomy device 102 is deployed. In some embodiments, the guidewire 104 is silicone coated, or uncoated (bare), or otherwise does not include a PTFE coating. The atherectomy system according to some embodiments of the present disclosure includes a guidewire 104 that includes a PTFE coating, or the atherectomy system according to some embodiments of the present disclosure does not include a guidewire 104.

[0030]

[0040] 1 , the atherectomy 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 an atherectomy procedure. The catheter 108 is coupled to the handle 106 and extends distally relative to the handle 106. The catheter 108 is configured to be positioned within the vasculature of a subject (e.g., a patient) during an atherectomy procedure to facilitate removal of occlusive material (e.g., plaque) from the vasculature. In some embodiments, and as illustrated, a distal portion 110 of the catheter 108 has a curved shape or configuration. In some embodiments, the distal portion 110 of the catheter 108 has a normally curved configuration (with "normal" being understood to mean that the catheter 108 is not subject to any external contact forces, e.g., due to contact with a vessel wall), and is deflected to another configuration. In other embodiments, the distal portion 110 of the catheter 108 has a generally straight shape or configuration and is deflected into other configurations. In some embodiments, the catheter 108 is selectively rotatable relative to the handle 106 about a catheter rotation axis 112 to facilitate proper positioning and / or "sweeping" of the distal portion 110 of the catheter 108 during the atherectomy procedure. In some embodiments, and as illustrated, 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 coupled to a cutter assembly 118 extending distally from the outer sheath 116. The cutter assembly 118 is described in further detail below.

[0031]

[0041] 2A-2C show a distal portion 110 of a catheter 108 that includes, among other components, an outer sheath 116 and a cutter assembly 118. The cutter assembly 118 includes a ferrule 200 coupled to and extending distally from the outer sheath 116. The cutter assembly 118 further includes a housing 202 coupled to and extending distally from the ferrule 200. The housing 202 rotatably holds the cutting elements. With particular reference to FIGS. 2B-2C, the housing 202 rotatably holds a first or distal cutting element 204 and a second or proximal cutting element 206. Rotation of the first cutting element 204 and the second cutting element 206 about an axis of rotation 208 in a rotational direction 210 relative to the housing 202 causes the cutting elements 204, 206 to cut the occlusive material and transport the occlusive material into the housing 202 (a process also referred to as "removal").

[0032]

[0042] 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 212 (see FIG. 2C) for coupling to the second cutting element 206. The second cutting element 206 is generally located within the housing 202, and in some embodiments, and as shown, is located entirely within the housing 202. The second cutting element 206 is also generally located more proximally than the first cutting element 204, but includes a shaft or stem 214 received in the central opening 212. The stem 214 may be coupled to the first cutting element 204 by a variety of techniques. For example, the stem 214 may be coupled to the first cutting element 204 by welding. In some embodiments, and as shown, the stem 214 extends distally relative to the first cutting element 204. The stem 214 includes an inner lumen 216 for receiving a guidewire (shown separately).

[0033]

[0043] 2C, the atherectomy device 102 further includes a rotatable drive shaft 218 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 218, which in turn rotates the first cutting element 204 and the second cutting element 206 to facilitate severing the occlusive material and transporting the occlusive material within the housing 202. In some embodiments, the cutter assembly 118 captures the severed occlusive material from the blood without the use of vacuum suction. In other embodiments, vacuum suction assists in capturing the severed occlusive material.

[0034]

[0044] 2C , in some embodiments, the atherectomy device 102 further includes an internal conveyor 220 coupled to and rotating with the drive shaft 218. The occlusive material is conveyed within the cutter housing 202 by the first cutting element 204 and the second cutting element 206, and the conveyor 220 moves the severed occlusive material proximally through the catheter 108 for evacuation outside the subject's body. In some embodiments, this conveyance occurs without the use of vacuum suction assistance. In other embodiments, vacuum suction assists in the conveyance of the severed occlusive material.

[0035]

[0045] The cutter assembly 118 has features that allow the cutting elements 204, 206 to repeatedly translate distally and proximally or oscillate in a translational direction relative to the housing 202 during the atherectomy process. In some circumstances, such motion causes the cutting elements 204, 206 to make relatively small, intermittent cuts in the occlusive material. This facilitates efficient cutting and transport of relatively small amounts of occlusive material, which in turn reduces the likelihood of clogging and, in some cases, results in more effective cutting of relatively hard occlusive material, such as calcium. More specifically, and with reference to FIGS. 3A and 3B, the housing 202 includes an inner housing bearing surface 300 and the second cutting element 206 includes one or more cutter bearing surfaces 302 (e.g., includes four cutter bearing surfaces 302, three of which are visible in FIGS. 3A and 3B). As the cutter assembly 118 is advanced against the occlusive material and the cutting elements 204, 206 rotate relative to the housing 202 to cut the occlusive material, the cutting elements 204, 206 convey the occlusive material in a proximal direction, as described above. This action moves the cutting elements 204, 206 in a distal direction. That is, this action translates the cutting elements 204, 206 from the position shown in FIG. 3A to the position shown in FIG. 3B, and the drive shaft 218 is extended or elongated axially. When the cutting elements 204, 206 reach the position shown in FIG. 3B, the cutter bearing surface 302 engages the housing bearing surface 300, which prevents the cutting elements 204, 206 from further translating distally relative to the housing 202. As a result, and provided that the cutter assembly 118 is advanced at a sufficiently slow rate (e.g., 1 mm / sec or less), the cutting elements 204, 206 are prevented from cutting and transporting further occlusive material in a proximal direction. Thus, the cutting elements 204, 206 are not advanced distally by the occlusive material, the drive shaft 218 axially shortens or relaxes, and the cutting elements 204, 206 translate from the position shown in FIG. 3B to the position shown in FIG. 3A.3A, the second cutting element 206 engages the ferrule 200. The process then repeats until the cutter assembly 118 has advanced or the cutting elements 204, 206 have rotated.

[0036]

[0046] The cutting elements 204, 206 translate various distances relative to the housing 202 during the above-mentioned steps. In some embodiments, the cutting elements 204, 206 translate a distance between 0.010 inches and 0.035 inches relative to the housing 202 during the above-mentioned steps. In some embodiments, the cutting elements 204, 206 translate a distance between 0.015 inches and 0.030 inches relative to the housing 202 during the above-mentioned steps.

[0037]

[0047] The features of the cutter assembly 118 that enable the cutting elements 204, 206 to repeatedly oscillate in a translational direction relative to the housing 202 are described in other ways. For example, the housing 202 is described as including an inner cutter translation chamber 304, and the second cutting element 206 is described as including a cutter limiter 306 rotatably received in the cutter translation chamber 304. The cutter limiter 306 is translatable together with the cutter translation chamber 304 from a first position (more specifically, the position shown in FIG. 3A) to a second position (more specifically, the position shown in FIG. 3B) and vice versa. As the cutter assembly 118 is advanced against the occluding material and the cutting elements 204, 206 rotate relative to the housing 202 to cut the occluding material, the cutting elements 204, 206 convey the occluding material in a proximal direction as described above. This action moves the cutting elements 204, 206 from the first position towards the second position and the drive shaft 218 is extended or stretched axially. When the cutting elements 204, 206 reach the second position, the cutter restriction 306 reaches the distal end 308 of the cutter translation chamber 304, which prevents the cutting elements 204, 206 from further translating distally relative to the housing 202. As a result, and provided the cutter assembly 118 is advanced at a sufficiently low speed (e.g., 1 mm / sec or less), the cutting elements 204, 206 are prevented from cutting and transporting further occlusion material proximally. Thus, the cutting elements 204, 206 are not advanced distally by the occlusion material and the drive shaft 218 is axially shortened or relaxed, allowing the cutting elements 204, 206 to translate from the second position to the first position. When the cutting elements 204, 206 reach the first position, the second cutting element 206 reaches the proximal end 310 of the cutter translation chamber 304. The process is then repeated until the end of the cutter assembly 118 progression or the rotation of the cutting elements 204, 206.

[0038]

[0048] 4A-4C, the first cutting element 204 includes one or more first, or distal, cutting flutes or blades extending distally relative to the housing 202. In some embodiments, and as shown, the first cutting element 204 includes two distal cutting blades 400. In some embodiments, the first cutting element 204 includes a different number of cutting blades, for example, three, four, five, six, seven, eight, nine, ten, or even more cutting blades. In some embodiments, and as shown, one or more of the distal cutting blades 400 extend helically relative to the axis of rotation 208 of the first cutting element 204 and the second cutting element 206.

[0039]

[0049] 4C , in some embodiments, the distal cutting blade 400 has a positive rake angle 402. That is, the distal cutting blade 400 has a rake angle 402 measured between an imaginary radius 404 extending from the axis of rotation 208 of the first cutting element 204 to the radially furthest edge 406 of the cutting blade 400 and a tangent 408 from an inner surface 410 of the cutting blade 400 at the radially furthest edge 406. The rake angle 402 is in the same direction as the direction of rotation 210 of the first cutting element 204 and the second cutting element 206 about the axis of rotation 208. In some embodiments, the rake angle 402 is in the range of 40 degrees to 80 degrees. In some embodiments, the rake angle 402 is in the range of 45 degrees to 75 degrees. In some embodiments, the rake angle 402 is in the range of 40 degrees to 70 degrees. In some embodiments, the rake angle 402 is within a range of 45 degrees to 65 degrees. In some embodiments, the rake angle 402 is within a range of 50 degrees to 60 degrees. In some embodiments, the rake angle 402 is substantially 55 degrees (i.e., 55 degrees ± 2.5 degrees).

[0040]

[0050] 5A-5B, the second cutting element 206 includes one or more second, or proximal, cutting flutes or blades 500. In some embodiments, the second cutting element 206 includes twice as many blades 500 as the first cutting element 204. In some embodiments, and as shown, the second cutting element 206 includes four cutting blades 500. In some embodiments, and as shown, the proximal cutting blades 500 extend helically relative to the axis of rotation 208 of the first cutting element 204 and the second cutting element 206. In some embodiments, and with particular reference to FIG. 5B, the proximal cutting blade 500 has a negative rake angle 502. In other words, the proximal cutting blade 500 has a rake angle 502 measured between an imaginary radius 504 extending from the axis of rotation 208 of the second cutting element to the radially furthest edge 506 of the cutting blade 500 and a tangent 508 from an inner surface 510 of the cutting blade 500 at the radially furthest edge 506. The rake angle 502 is in a direction opposite to the direction of rotation 210 of the first cutting element 204 and the second cutting element 206 about the axis of rotation 208. In further words, the inner surface 510 of the proximal cutting blade 500 slopes outwardly or forwardly of the cutting edge. In some embodiments, the rake angle 502 is in a range of 5 degrees to 45 degrees (also expressed as -5 degrees to -45 degrees). In some embodiments, the rake angle 502 is in a range of 6 degrees to 35 degrees (also expressed as -6 degrees to -35 degrees). In some embodiments, the rake angle 502 is within the range of 8 degrees to 24 degrees (also expressed as -8 degrees to -24 degrees). In some embodiments, the rake angle 502 is substantially 16 degrees (i.e., 16 degrees ± 2.5 degrees, also expressed as substantially -16 degrees (i.e., -16 degrees ± 2.5 degrees)).

[0041]

[0051] In some embodiments, the positive rake angle 402 of the first cutting element 204 and the negative rake angle 502 of the second cutting element 206 promote improved cutting efficiency and / or inhibit lodging of occlusive material within the housing 202. More specifically, in some embodiments, the positive rake angle 402 of the first cutting element 204 facilitates shearing and conveying the occlusive material toward the second cutting element 206, and the negative rake angle 502 of the second cutting element 206 facilitates moving the occlusive material radially outward and proximally toward the housing 202, thereby inhibiting lodging of the occlusive material within the housing 202.

[0042]

[0052] In some embodiments, and as shown, a cutter bearing surface 302 is formed on each of the proximal cutting blades 500. In some embodiments, and as shown, the cutter bearing surface 302 is disposed between the distal end 512 and the proximal end 514 of the proximal cutting blade 500. In such embodiments, the cutter bearing surface 302 is disposed at any of a variety of locations between the distal end 512 and the proximal end 514 of the proximal cutting blade 500. In some embodiments, the cutter bearing surface 302 is disposed at other locations, such as, for example, at the distal end 512 of the proximal cutting blade 500.

[0043]

[0053] In some embodiments, and as shown, the cutting stem 214 further includes one or more cutting features 516 that facilitate breaking down the obstructing material into smaller particles that are captured and removed by the atherectomy system 100. In some embodiments, and as shown, the cutting stem 214 includes two cutting features 516. In other embodiments, the cutting stem 214 includes a different number of cutting features 516 (e.g., 1, 3, 4, 5, 6, 7, 8, 9, 10, or more cutting features 516). In some embodiments, the cutting features 516 are negative features (e.g., depressions formed in the surface of the cutting stem 214 as shown, or channels formed in the surface of the cutting stem 214). In some embodiments, the cutting features 516 are positive features (e.g., ridges or protrusions extending from the surface of the cutting stem 214). In some embodiments, the cutting feature 516 extends substantially proximally from the leading end 518 of the cutting stem 214. In some embodiments, the cutting feature 516 is located away from the leading end 518 and / or does not extend proximally along the stem 214.

[0044]

[0054] The foregoing description has been presented for purposes of illustration and description. The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. For example, in the foregoing summary, various features of the disclosure are grouped together in one or more aspects, embodiments, and / or configurations for the purpose of streamlining the disclosure. Features of the aspects, embodiments, and / or configurations of the disclosure may be combined in alternative aspects, embodiments, and / or configurations other than those described above. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects may lie in less than all features of one foregoing disclosed aspect, embodiment, and / or configuration. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure.

[0045]

[0055] Further, while the description includes a description of one or more aspects, embodiments, and / or configurations and specific variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, such as would be within the skill and knowledge of one of ordinary skill in the art after appreciating the disclosure. It is intended to acquire the right to include, to the extent permitted, alternative aspects, embodiments, and / or configurations having such alternative, interchangeable, and / or equivalent structures, functions, ranges, or steps to those recited in the claims, whether or not alternative, interchangeable, and / or equivalent structures, functions, ranges, or steps are disclosed herein, and no attempt is made to dedicate any patentable subject matter to the public.

Claims

1. A handle operated by a user; a catheter coupled to the handle, the catheter comprising an outer sheath and a drive shaft, the drive shaft positioned within the outer sheath and rotatable relative to the outer sheath; a cutter assembly; and The cutter assembly includes: a housing coupled to the outer sheath and extending distally from the outer sheath, the housing comprising a housing bearing surface; a cutting element rotatably and translationally carried by the housing, the cutting element coupled to and extending distally from the drive shaft; The cutting element is at least one cutting blade that cuts occlusive material upon rotation of the cutting element relative to the housing; a cutter bearing surface engaging the housing bearing surface; rotating the cutting element relative to the housing, causing the at least one cutting blade to sever occlusive material and convey the severed occlusive material in a proximal direction, thereby translating the cutting element distally relative to the housing until the cutter bearing surface engages the housing bearing surface; Atherectomy devices.

2. as the cutting element translates distally relative to the housing, the drive shaft extends axially and when the cutter bearing surface engages the housing bearing surface, severing and delivery of severed occlusive material ceases and the drive shaft shortens axially to permit translation of the cutting element proximally relative to the housing. The atherectomy device of claim 1 .

3. the cutter assembly further comprising a ferrule coupled to the housing, wherein when the cutter bearing surface engages the housing bearing surface, severing and delivery of severed occlusive material is inhibited and the drive shaft is axially shortened such that the cutting element translates proximally relative to the housing such that the cutting element engages the ferrule. The atherectomy device of claim 1 .

4. the cutting element is translatable relative to the housing over a distance of 0.010 inches to 0.035 inches; The atherectomy device of claim 1 .

5. the cutting element is translatable relative to the housing over a distance of 0.015 inches to 0.030 inches; The atherectomy device of claim 1 .

6. the cutting element is a proximal cutting element, the cutter assembly further comprising a distal cutting element, the distal cutting element coupled to the proximal cutting element and rotatable with the proximal cutting element relative to the housing, the distal cutting element comprising at least one cutting blade. The atherectomy device of claim 1 .

7. the cutter bearing surface is located between a distal end and a proximal end of the at least one cutting blade; The atherectomy device of claim 1 .

8. A handle operated by a user; a catheter coupled to the handle, the catheter comprising an outer sheath and a drive shaft, the drive shaft positioned within and rotatable relative to the outer sheath; a cutter assembly; and The cutter assembly includes: a housing coupled to and extending distally from the outer sheath, the housing comprising a cutter translation chamber; a cutting element rotatably and translationally carried by the housing, the cutting element coupled to and extending distally from the drive shaft; The cutting element is at least one cutting blade that cuts occlusive material upon rotation of the cutting element relative to the housing; a cutter limiter rotatably received in the cutter translation chamber and translatable within the cutter translation chamber from a first position to a second position and from the second position to the first position; the cutting element rotates relative to the housing, causing the at least one cutting blade to cut occlusive material and transport the cut occlusive material in a proximal direction, whereby the cutter limiter rotates and translates within the cutter translation chamber from the first position to the second position, the cutting element translates distally relative to the housing, and when the cutter limiter reaches the second position, the cutter limiter translates from the second position to the first position, and the cutting element translates proximally relative to the housing. Atherectomy devices.

9. As the cutting element translates distally relative to the housing, the drive shaft extends axially, and when the cutter limiter reaches the second position, distal translation of the cutting element is prevented, severing and delivery of cut occlusive material is no longer possible, and the drive shaft shortens axially, causing translation of the cutting element in a proximal direction relative to the housing.

9. The atherectomy device of claim 8.

10. when the cutter limiter translates from the first position to the second position, the cutting element translates relative to the housing over a distance of 0.010 inches to 0.035 inches.

9. The atherectomy device of claim 8.

11. when the cutter limiter translates from the first position to the second position, the cutting element translates relative to the housing over a distance of 0.015 inches to 0.030 inches.

9. The atherectomy device of claim 8.

12. the cutting element is a proximal cutting element, the cutter assembly further comprising a distal cutting element, the distal cutting element coupled to the proximal cutting element and rotatable therewith relative to the housing, the distal cutting element comprising at least one cutting blade.

9. The atherectomy device of claim 8.

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