Hybrid atherectomy devices

Abstract

To provide telescoping, self-driving and laterally-pushing atherectomy devices.SOLUTION: Telescoping, self-driving and laterally-pushing atherectomy devices are provided, each having a flexible sheath, a cutter with helical flutes, and a drive assembly. The drive assembly can have a flexible driveshaft rotatably translational with the lumen of the flexible sheath, a positive displacement pump to transport cut tissue, and a flexible drive shaft that can be longer than the flexible sheath for a reversible telescoping of the drive assembly from the lumen of the flexible sheath. The positive displacement pump can be a screw pump having a drive screw portion exposed for contact with a vascular lumen for a self-driving of the device through the vascular lumen. A reversibly-expandable, lateral pushing member can be included at the distal end of the flexible sheath for a lateral pushing of the cutter. Improved cutting heads, and methods of making them, are provided for cutting a combination of soft and hard plaque.SELECTED DRAWING: Figure 4D

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Application No. 17 / 833,967, filed June 7, 2022, which claims the benefit of U.S. Provisional Application No. 63 / 197,970, filed June 7, 2021, each of which is incorporated herein by reference in its entirety. [Background technology]

[0002] FIELD OF THE INVENTION The teachings herein are generally directed to medical devices and methods, including devices and methods for performing atherectomy through both soft and hard vascular plaques.

[0003] 2. Description of Related Art Atherectomy is a minimally invasive procedure that removes atherosclerosis from blood vessels in the body and is an alternative to angioplasty in treating narrowed arteries. Common applications include peripheral artery disease and coronary artery disease. Unlike angioplasty and stents, which push plaque into the vessel wall, atherectomy cuts the plaque from the vessel wall. Atherectomy is typically used to remove plaque from arteries, but can also be used in veins and vascular bypass grafts. Summary of the Invention

[0004] Atherectomy may offer an improvement over balloon dilatation and stent placement, which are considered traditional interventional surgical methods for treating atherosclerosis. During balloon dilatation, a folded balloon is inserted into the blood vessel and inflated to compress plaque against the vessel wall. A stent can then be deployed to hold the plaque in place as a scaffold to maintain the integrity of the vessel's lumen. However, these traditional treatments can stretch the artery, potentially inducing scar tissue formation, and stent placement can cut arterial tissue, potentially inducing scar tissue formation. Scar tissue formation can lead to restenosis of the artery. Furthermore, balloon dilatation can cause tears in the vessel wall. Because atherectomy expands the lumen by removing plaque rather than stretching the vessel, it reduces the risk of vascular injury, such as dissection, which can lead to increased restenosis. [Problem to be solved by the invention]

[0005] Unfortunately, cutting-edge atherectomy devices face performance limitations. For example, current devices equipped with rotary cutters cannot effectively process a variety of soft, fibrous, and calcified plaque types. They either fail to cut all types or shatter the plaque into large fragments, which remain in the arterial bed as emboli that can clog downstream vessels. Because plaque is tissue composed of fat, cholesterol, calcium, fibrous connective tissue, and other substances found in the body, it is highly diverse and is primarily classified into four distinct types: calcified and hard, necrotic and soft, fibrous, and combinations thereof. Calcified plaque can be as hard as bone, while fatty plaque is typically soft. Fibrous plaque is typically viscoelastic—stretchy yet hard—making it difficult to cut. Some cutting-edge devices are equipped with burrs that can scrape away hard plaque but cannot cut soft or viscoelastic plaque. Worse yet, they may loosen fragments that could become dangerous emboli. Some cutting-edge devices have sharp cutters that can cut off-center to one side of the vessel, which is desirable but does not allow for effective control of the amount of deflection. Also, some cutting-edge devices have a "nose cone" that prevents the cutter from cutting through the lesion, preventing the device from advancing far enough to reach the cutter blade.

[0006] Most importantly, however, patients with "blocked" or "stubborn" lesions currently cannot be treated with balloons, stents, or atherectomy devices. These lesions are occlusions that leave only very small luminal openings or no openings at all, making passage of a guidewire, let alone a balloon or stent over a guidewire, difficult or impossible. For example, while a lumen opening as small as 0.5 mm may allow passage of a guidewire, the smallest stent is 1.0 mm, and the smallest balloon is 0.75 mm, neither of which can pass through small, stubborn lesions for treatment. And, as noted above, current atherectomy devices have difficulty ablating plaque even if a guidewire can pass through the luminal opening. The problem is even worse in situations where a complete occlusion is present.

[0007] Thus, those skilled in the art will appreciate an atherectomy device that (i) can effectively cut and remove four different types of plaque tissue: calcified and hard, necrotic and soft, fibrotic, and combinations thereof; (ii) can provide a concentric vessel lumen with minimal plaque burden; (iii) can safely self-collect and remove plaque particles to avoid embolic release; and (iv) can effectively treat a vessel while reducing the risk of vascular injury that may lead to increased restenosis. Furthermore, those skilled in the art will certainly appreciate that (v) they have an atherectomy device that can handle these clogged or tough lesions. In some embodiments, the atherectomy cutters and devices taught herein may be referred to as "hybrid" cutters and devices due to their ability to cut combinations of soft and hard plaque, a feature that will be appreciated by those skilled in the art. [Means for solving the problem]

[0008] Provided are atherectomy devices and methods for their use that (i) effectively cut and remove four different types of plaque tissue: calcified and hard, necrotic and soft, fibrotic, and combinations thereof; (ii) provide a concentric vessel lumen with minimal plaque burden; (iii) safely self-collect and remove plaque particles to avoid embolic release; (iv) effectively treat vessels while reducing the risk of vascular injury that may lead to increased restenosis; and importantly, (v) address clogged or stubborn lesions with little or no intralesional luminal opening. The atherectomy devices taught herein may be telescopic, self-actuated, side-pushing, or a combination thereof.

[0009] In some embodiments, the atherectomy device is a telescoping atherectomy device. In these embodiments, the device includes a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the longitudinal direction. The device includes a flexible sheath having an outer diameter and a sheath lumen; a cutter having a body with a proximal end, a distal end, and a plurality of helical grooves, a point at the distal end with a plurality of cutting lips, a cutter lumen, and a clear diameter; and a drive assembly. The drive assembly includes a flexible drive shaft having an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath. The drive assembly also includes a positive displacement pump at the distal end of the drive shaft adjacent to the helical grooves at the proximal end of the cutter to initiate pumping. And in these embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible drive shaft; the flexible drive shaft may be longer than the flexible sheath and allow the drive assembly to be reversibly extended and retracted from the lumen of the flexible sheath at the distal end of the flexible sheath; and the guidewire lumen may include a cutter lumen and a drive shaft lumen.

[0010] In some embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible sheath, and in some embodiments, the positive displacement pump may be a screw pump attached to the outer surface of the drive shaft, the distal end of the screw pump adjacent the helical groove in the proximal end of the cutter.

[0011] In some embodiments, the telescoping atherectomy device may be self-acting. For example, the screw pump may extend beyond the flexible sheath and be exposed to contact the lumen of the blood vessel during use of the atherectomy device within the lumen of the blood vessel. In some embodiments, the screw pump may be right-handed when the cutter rotates clockwise. In some embodiments, the screw pump may be left-handed when the cutter rotates counterclockwise.

[0012] In some embodiments, the telescoping atherectomy device can further include a reversibly expandable lateral pusher member at the distal end of the flexible sheath. In some embodiments, the telescoping atherectomy device can further include a reversibly expandable lateral pusher member at the distal end of the flexible sheath, the lateral pusher member having a proximal end, a distal end, a collapsed state, and an expanded state, the proximal end being operatively connected to the flexible sheath and the distal end being operatively connected to the cutter. The operative connection with the flexible sheath and the operative connection with the cutter can each be configured to receive an axial force (i) applied along the axis of the flexible drive shaft from the cutter to the flexible sheath, and (ii) traveling through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and contraction of the flexible drive shaft from the flexible sheath. Additionally, the operable connection with the cutter may be configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device.

[0013] In some embodiments, the atherectomy device is a self-actuating atherectomy device. In some embodiments, the device can have a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the longitudinal direction. The device can include a flexible sheath having an outer diameter and a sheath lumen; a cutter having a body with a proximal end, a distal end, and a plurality of helical grooves, a point at the distal end with a plurality of cutting lips, a cutter lumen, and a clear diameter; and a drive assembly. The drive assembly can include a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath. The drive assembly can also include a screw pump attached to the outer surface of the drive shaft, adjacent to the helical grooves at the proximal end of the cutter, and including a drive screw portion. In some embodiments, the drive screw portion can extend beyond the flexible sheath and be exposed for contact with the vascular lumen during use of the atherectomy device within the vascular lumen. In some embodiments, the drive screw portion can be right-handed when the cutter is rotated in a right direction; and in some embodiments, the drive screw portion can be left-handed when the cutter is rotated in a left direction. And, in some embodiments, the clear diameter of the cutter is larger than the outer diameter of the flexible drive shaft; and the guidewire lumen can encompass the cutter lumen and the drive shaft lumen.

[0014] In some embodiments, the clear diameter of the cutter of the self-actuating atherectomy device may be greater than the outer diameter of the flexible sheath, and in some embodiments, the drive screw portion may be the distal portion of the screw pump.

[0015] In some embodiments, the flexible drive shaft of the self-actuating atherectomy device is longer than the flexible sheath, allowing the drive assembly to be reversibly extended and retracted from the lumen of the flexible sheath at the distal end of the flexible sheath.

[0016] In some embodiments, the self-actuating atherectomy device can further include a reversibly expandable lateral pusher member at the distal end of the flexible sheath. In some embodiments, the lateral pusher member can have a proximal end, a distal end, a collapsed state, and an expanded state, a proximal end operatively connected to the flexible sheath, and a distal end operatively connected to the cutter. The operative connection with the flexible sheath and the operative connection with the cutter can each be configured to receive an axial force (i) applied from the cutter along the axis of the flexible drive shaft to the flexible sheath, and (ii) transferred through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and retraction of the flexible drive shaft from the flexible sheath. Furthermore, the operative connection with the cutter can be configured as a rotatably translatable connection to facilitate rotation of the cutter and the flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device.

[0017] In some embodiments, the atherectomy device is a lateral-push atherectomy device. In some embodiments, the device can have a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the longitudinal direction. The device can include a flexible sheath having an outer diameter and a sheath lumen; a cutter having a body with a proximal end, a distal end, and a plurality of helical grooves, a point at the distal end with a plurality of cutting lips, a cutter lumen, and a clear diameter; and a drive assembly. The drive assembly can include a flexible drive shaft having an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath. The drive assembly can include a positive displacement pump at the distal end of the drive shaft adjacent to the helical grooves at the proximal end of the cutter to initiate pumping. The lateral push atherectomy device can have a reversibly expandable lateral push member at the distal end of the flexible sheath. In some embodiments, the clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; and the guidewire lumen can include a cutter lumen and a drive shaft lumen.

[0018] In some embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible sheath.

[0019] In some embodiments, the lateral pusher member can have a proximal end, a distal end, a collapsed state, and an unfolded state, a proximal end operatively connected to the flexible sheath, and a distal end operatively connected to the cutter. In some embodiments, the operative connection with the flexible sheath and the operative connection with the cutter can each be configured to receive an axial force (i) applied from the cutter along the axis of the flexible drive shaft to the flexible sheath, and (ii) traveling through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and retraction of the flexible drive shaft from the flexible sheath. In some embodiments, the operative connection with the cutter can be configured as a rotatably translatable connection to facilitate rotation of the cutter and the flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device.

[0020] In some embodiments, the flexible drive shaft of the lateral pushing atherectomy device is longer than the flexible sheath and can reversibly extend and retract the drive assembly from the lumen of the flexible sheath at the distal end of the flexible sheath. And, in some embodiments, the lateral pushing atherectomy device can further include a drive screw attached to the outer surface of the distal end of the drive shaft and adjacent to the screw pump at the distal end of the screw pump. The drive screw can extend beyond the flexible sheath and be exposed for contact with the vascular lumen during use of the atherectomy device within the vascular lumen. In some embodiments, the drive screw can be right-handed when rotating the cutter in a right direction; and, in some embodiments, the drive screw can be right-handed when rotating the cutter in a right direction.

[0021] Systems are also provided. In some embodiments, any of the atherectomy devices taught herein can be a system including an atherectomy device and a guidewire.

[0022] Methods for performing atherectomy in a subject using any of the atherectomy devices taught herein are provided. In some embodiments, the method includes: creating an entry point in the subject's vascular lumen; inserting the atherectomy device into the vascular lumen; extending and retracting a flexible drive shaft; using the cutter of the atherectomy device to cut plaque from the vascular lumen; using a positive displacement pump to eject the cut plaque from the vascular lumen; and removing the atherectomy device from the subject's vascular lumen.

[0023] In some embodiments, the method can include creating an entry point in the vascular lumen of the subject; inserting an atherectomy device into the vascular lumen; driving the atherectomy device through the vascular lumen using an exposed drive screw; severing the plaque from the vascular lumen using a cutter of the atherectomy device; ejecting the severed plaque from the vascular lumen using a positive displacement pump; and removing the atherectomy device from the vascular lumen of the subject.

[0024] Similarly, in some embodiments, the method can include creating an entry point in the lumen of a blood vessel of the subject; inserting an atherectomy device into the lumen of the blood vessel; pushing a distal portion of the atherectomy device laterally within the lumen of the blood vessel, the pushing including expanding a lateral pushing member; severing the plaque from the lumen of the blood vessel using a cutter of the atherectomy device; ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the blood vessel of the subject.

[0025] In some embodiments, a hybrid atherectomy cutter for cutting a combination of soft and hard plaques is provided. The cutter can include a proximal end, a distal end, a longitudinal axis, and a cutting length defined by the distance from the proximal end to the distal end along the longitudinal axis. The cutter can have a radius at the distal end with an inner inflection point and an outer inflection point. In some embodiments, the cutter can have first and second primary cutting edges that extend spirally along the radius from the distal end to the proximal end. The cutter can have first and second spiral grooves, each having a helix angle and forming an open spiral channel at the distal and proximal ends. The cutter can also have a cutting diameter, which is the maximum distance between the first and second primary cutting edges measured perpendicular to the longitudinal axis. The cutter can also have a core having a core diameter, a distal end, and a proximal end, the distal end of the core configured with a first plurality of secondary facets forming a first secondary cutting edge at the distal end of the first spiral groove, and the second plurality of secondary facets forming a second secondary cutting edge at the distal end of the second spiral groove. The cutter can also have a lumen configured to allow a guidewire to pass therethrough. Such a cutter has the desired function of effectively cutting both soft and hard plaques within a blood vessel.

[0026] Those skilled in the art will appreciate that the radius of the distal end of the cutter can have any desired shape. In some embodiments, the radius is a ball nose radius. In some embodiments, the radius is a corner radius. And, in some embodiments, the radius is equal to half the diameter of the cutter.

[0027] Those skilled in the art will understand that each of the grooves can be helical in shape and have any desired angle of helix, such that combinations of grooves can have the same helix angle or a combination of helix angles. Furthermore, the grooves of a cutter can have the same or different angles compared to the other grooves; for example, one skilled in the art can select a cutter with this configuration for a smoother cut. And, in some embodiments, the groove angle can be constant or variable; for example, one skilled in the art can select a "variable helix," i.e., a variable groove angle between grooves, for materials that may be more resistant to cutting and potentially increase the efficiency of the cut. Helix angles greater than 45° are considered "high angles" and remove material from the cut site more efficiently, leaving a smoother cut surface while reducing tissue packing and tissue recutting; whereas, helix angles less than 40° are considered "low angles" and remove larger pieces of material in a given cutting time, leaving a rougher cut surface, and possibly resulting in tissue packing or recutting depending on the application. In some embodiments, the grooves can have a high helix angle; and, in some embodiments, the grooves can have a low helix angle.

[0028] Those skilled in the art will recognize that cutters include secondary facets created to generate secondary cutting edges. In some embodiments, the distal end of the core can be configured with a first plurality of secondary facets that form a first secondary cutting edge at the distal end of the first spiral groove; and in some embodiments, the distal end of the core can be configured with a second plurality of secondary facets that form a second secondary cutting edge at the distal end of the second spiral groove.

[0029]

[0010] Embodiments also include cutters having primary facets for improving tissue cutting by the primary cutting blades. In some embodiments, the distal end of the core further includes a plurality of first primary facets at the distal end of the first primary cutting blade; and in some embodiments, the distal end of the core further includes a plurality of second primary facets at the distal end of the second primary cutting blade. In some embodiments, the plurality of first primary facets can be configured to extend the reach of the first primary cutting blade; and similarly, the plurality of second primary facets can be configured to extend the reach of the second primary cutting blade.

[0030] In some embodiments, the cutter can have a third primary cutting edge that extends spirally along a radius from the distal end to the proximal end; and a third helical groove having a helix angle and forming a helical channel that is open at the distal and proximal ends. In some embodiments, the core can further be configured with a third plurality of secondary facets that form the third secondary cutting edge at the distal end of the third helical groove. Similarly, the core can further be configured with a third plurality of primary facets at the distal end of the third primary cutting edge, the third plurality of primary facets being configured to extend a distal extent of the third primary cutting edge.

[0031] In some embodiments, the cutter can have a third primary cutting edge extending spirally along a radius from the distal end to the proximal end; a fourth primary cutting edge extending spirally along a radius from the distal end to the proximal end; a third spiral groove having a helix angle and forming an open spiral channel at the distal and proximal ends; and a fourth spiral groove having a helix angle and forming an open spiral channel at the distal and proximal ends. In some embodiments, the core can further comprise a third plurality of secondary facets forming a third secondary cutting edge at a distal end of the third spiral groove; and a fourth plurality of secondary facets forming a fourth secondary cutting edge at a distal end of the third spiral groove. Similarly, the core can be configured to further include a third plurality of primary facets at a distal end of the third primary cutting edge, the third plurality of primary facets configured to extend a distal extent of the third primary cutting edge; and a fourth plurality of primary facets at a distal end of the fourth primary cutting edge, the fourth plurality of primary facets configured to extend a distal extent of the fourth primary cutting edge.

[0032] Those skilled in the art will understand that any of the atherectomy devices taught herein can include any of the cutters taught herein. In some embodiments, the atherectomy device includes: a cutter as taught herein, the cutter having a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the longitudinal direction; a flexible sheath having an outer diameter and a sheath lumen; and a drive assembly, the drive assembly including a flexible drive shaft having an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; the drive assembly also includes a positive displacement pump at the distal end of the drive shaft adjacent to a helical groove in the proximal end of the cutter to initiate pumping. In these embodiments, the clear diameter of the cutter is larger than the outer diameter of the flexible drive shaft; the flexible drive shaft is longer than the flexible sheath and allows the drive assembly to be reversibly extended and retracted from the lumen of the flexible sheath at the distal end of the flexible sheath; and the guidewire lumen can encompass the cutter lumen and the drive shaft lumen.

[0033] In some embodiments, the atherectomy device comprises: a cutter as taught herein, said cutter having a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; a drive assembly having a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter; wherein the flexible drive shaft rotatably translates with the lumen of the flexible sheath, and the drive assembly also has a screw pump attached to the outer surface of the drive shaft and adjacent to a helical groove in the proximal end of the cutter, the screw pump including a drive screw portion; wherein the drive screw portion extends beyond the flexible sheath and is exposed for contact with the vascular lumen during use of the atherectomy device within the vascular lumen; and wherein when the cutter is rotated in a right direction, the threads are right-handed; or when the cutter is rotated in a left-handed direction, the threads are left-handed. In these embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible drive shaft; and the guidewire lumen may include the cutter lumen and the drive shaft lumen.

[0034] In some embodiments, the atherectomy device includes: a cutter as taught herein, the cutter having a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; a drive assembly having a flexible drive shaft comprising an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; and a positive displacement pump at the distal end of the drive shaft that initiates pumping adjacent to a helical groove in the proximal end of the cutter. And, the atherectomy device can also include a reversibly expandable lateral pusher member at the distal end of the flexible sheath, the lateral pusher member having a proximal end, a distal end, a collapsed state, and an expanded state, the proximal end in operable connection with the flexible sheath, and the distal end in operable connection with the cutter. In some embodiments, the clear diameter of the cutter is larger than the outer diameter of the flexible drive shaft; and the guidewire lumen can include a cutter lumen and a drive shaft lumen. Furthermore, the operable connection with the flexible sheath and the operable connection with the cutter may each be configured to receive an axial force (i) applied from the cutter along the axis of the flexible drive shaft to the flexible sheath, and (ii) moved through the lateral push member during contraction and expansion of the lateral push member by reversibly extending and retracting the flexible drive shaft from the flexible sheath; and the operable connection with the cutter may be configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral push member during operation of the atherectomy device.

[0035] Those skilled in the art will also understand that any method of performing atherectomy can include using any of the atherectomy devices taught herein with any of the cutters taught herein. Regardless of the atherectomy device used, the method can include creating an entry point in the lumen of a subject's blood vessel; inserting the atherectomy device into the lumen of the blood vessel; extending and retracting a flexible drive shaft; severing plaque from the lumen of the blood vessel using the cutter of the atherectomy device; ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the subject's blood vessel. [Brief explanation of the drawings]

[0036] [Figure 1A-1B] 1A-1B illustrate arterial anatomy, intimal plaque, and plaque removal methods according to some embodiments. [Figure 1C] FIG. 1C illustrates arterial anatomy, intimal plaque, and a plaque removal method according to some embodiments.

[0037] [Figure 2A-2B] 2A and 2B show a telescoping atherectomy device, according to some embodiments.

[0038] [Figure 3] FIG. 3 illustrates an automatically actuatable telescoping atherectomy device, according to some embodiments.

[0039] [Figures 4A-4C] 4A-4C show a telescoping atherectomy device that may further comprise a reversibly expandable lateral push member at the distal end of the flexible sheath, the expansion of which induces curvature, according to some embodiments. [Figure 4D]FIG. 4D shows a telescoping atherectomy device that may further comprise a reversibly expandable lateral push member at the distal end of the flexible sheath, the expansion of which induces curvature, according to some embodiments.

[0040] [Figure 5A-5B] 5A-5B show compressible sleeves that can be used to increase the torsional stiffness of the lateral pusher members, inducing curvature upon expansion of the lateral pusher members, according to some embodiments. [Figure 5C-5D] 5C-5D show compressible sleeves that can be used to increase the torsional stiffness of the lateral pusher members, inducing curvature upon expansion of the lateral pusher members, according to some embodiments.

[0041] [Figures 6A-6B] 6A and 6B show other cutters that may be used, according to some embodiments.

[0042] [Figure 7A-7C] 7A-7C show cutter features including primary and secondary blades, grooves, helix angle, and guidewire lumen, according to some embodiments.

[0043] [Figures 8A-8D] 8A-8D show cutter characteristics, including cutting length, radius, and cutting diameter, according to some embodiments.

[0044] [Figures 9A-9C] 9A-9C show perspective, proximal and distal end views of primary and secondary blades and primary and secondary facets that improve the cutting of tissue by the cutter, according to some embodiments.

[0045] [Figures 10A-10B] 10A and 10B show a mapping of primary and secondary facets and their relationship to the primary and secondary cutting edges, according to some embodiments.

[0046] [Figures 11A-11C] 11A-11C illustrate a method of performing an atherectomy, according to some embodiments.

[0047] [Figure 12] FIG. 12 charts a method of performing an atherectomy, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0048] Atherectomy devices and methods for their use are provided that (i) can effectively cut and remove four different types of plaque tissue: calcified and hard, necrotic and soft, fibrous, and combinations thereof, including fibrocalcified tissue; (ii) can provide a concentric vessel lumen with minimal plaque burden; (iii) can safely self-collect and remove plaque particles to avoid embolic release; and (iv) can effectively treat blood vessels while reducing the risk of vascular injury that may lead to increased restenosis. And importantly, those skilled in the art will certainly appreciate the surprising (v) atherectomy device's ability to address clogged or robust lesions with little or no intralesional luminal opening. In some embodiments, the atherectomy cutters and devices taught herein may be referred to as "hybrid" cutters and devices due to their ability to cut combinations of soft and hard plaque, a feature that will be appreciated by those skilled in the art. The atherectomy devices taught herein may be telescoping, self-actuating, lateral pushing, or a combination thereof. The devices provided herein can, for example, form concentric lumens with minimal plaque burden (less than 30% of the vessel diameter) while avoiding damage to the vessel wall and minimizing embolization.

[0049] 1A-1C illustrate arterial anatomy, intimal plaque, and plaque removal methods according to some embodiments. FIG. 1A shows the anatomy of an artery 100. While arterial anatomy varies depending on the size of the artery, arteries share common characteristics: They transport oxygenated blood from the heart to small arterioles. The outermost layer is the tunica externa (tunica adventitia), which is composed of collagen fibers. The largest arteries, such as the aorta, also contain vasa vasorum (vasa vasorum), or small blood vessels that supply oxygen to the larger vessels. The next layer is the tunica media (tunica interna) or intima (tunica intima), which is also composed of smooth muscle and collagen fibers and is elastic. The next layer is the tunica interna (tunica intima), which is also elastic and composed of endothelial cells supported by a layer of collagen. All of these layers surround the vessel lumen, the wall where unwanted plaque forms and is removed by the atherectomy device taught herein. FIG. 1B shows plaque 110 deposited on the wall of arterial lumen 105 .

[0050] Those skilled in the art will appreciate that guidewires can be used to locate diseased or targeted areas within a blood vessel. Guidewires can also be used to guide the atherectomy devices taught herein, i.e., cutters, onto the targeted area. In some embodiments, the guidewire lumen can include a cutter lumen and a drive shaft lumen. In some embodiments, the diameter of the guidewire lumen can range from 0.01 to 0.20 inches, 0.01 to 0.18 inches, 0.01 to 0.15 inches, 0.01 to 0.10 inches, or any range of sizes therein, in some embodiments. In some embodiments, the diameter of the guidewire lumen can range from 0.01 to 0.14 inches. In some embodiments, the guidewire lumen diameter is 0.01 inch (0.254 mm), 0.02 inch (0.508 mm), 0.04 inch (1.016 mm), 0.06 inch (1.524 mm), 0.08 inch (2.032 mm), 0.10 inch (2.540 mm), 0.12 inch (3.048 mm), 0.14 inch (3.556 mm), 0.16 inch (4.064 mm), 0.18 inch (4.572 mm), 0.20 inch (5.080 mm), or any diameter in 0.01 inch (0.254 mm) increments therein.

[0051] FIG. 1C is a flowchart of an atherectomy method 150 that can be used with the atherectomy device taught herein to remove plaque from an artery. A guidewire is advanced through a guide catheter 174 across an obstruction in a blood vessel caused by arterial plaque in a target area. Once the guidewire is in place across the obstruction, an atherectomy device is advanced across the obstruction over the guidewire 176. The atherectomy device is then positioned to cut and remove the plaque in the target area, treating the artery and removing the obstruction 178. At this time, if necessary, a stent can be inserted into the target area to help maintain the newly formed opening in the lumen 180. To complete the procedure, the atherectomy device and guidewire are removed from the patient 182.

[0052] Generally speaking, an atherectomy device can include a cutter or cutting head attached to a drive shaft that rotates the cutter, the drive shaft rotating within a sheath. In some embodiments, the sheath may be interchangeably referred to as a "flexible tube"; and in some embodiments, the drive shaft may be referred to as a "torque shaft." In some embodiments, the cutter can be designed to extend or retract from the sheath, and in some embodiments, can be designed to reversibly extend or retract from the sheath. In some embodiments, the cutter can extend or retract to a desired extent from the sheath. For example, in some embodiments, the cutter can extend from the end of the sheath on the drive shaft, perhaps up to 10 mm to 500 mm. In some embodiments, the cutter can extend or retract from about 20 mm to about 200 mm, about 30 mm to about 100 mm, about 40 mm to about 80 mm, about 60 mm, or any range therein in 1 mm increments. In some embodiments, the cutter is extendable approximately 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 300 mm, 400 mm, 500 mm, or any amount or range therein in 1 mm increments. Extension allows the cutter and a distal portion of the drive shaft to advance forward of the sheath, thereby improving engagement between the cutter and plaque tissue. Furthermore, moving the cutter ahead of the sheath while the sheath remains stationary can allow the sheath to resist drill-through. In some methods, extension may be the only step in removing plaque from a vessel. In some embodiments, extension can provide an initial cutting path to facilitate subsequent, more targeted, eccentric cutting.

[0053] 2A and 2B illustrate a telescoping atherectomy device according to some embodiments. In these embodiments, the atherectomy device 200 can include a distal portion having a distal end 202, a proximal portion having a proximal end (not shown), a longitudinal axis having a central axis 205, and a guidewire lumen for a guidewire 210 passing through the device in the direction of the central axis 205. The general orientation directions from proximal to distal and distal to proximal are shown in FIG. 2A as perspective views. The device can include a proximal portion with a proximal end (not shown), a distal portion with a distal end 217, a flexible sheath 215 having an outer diameter 219, and a sheath lumen 221; a drive shaft 250; a cutter 230 having a proximal portion with a proximal end 232 and a distal portion with a distal end 234; and a body 236 with a plurality of spiral grooves 238 between cutter blades 240. The distal end 234 can have multiple cutting lips on the cutter blade 240, and in some embodiments, the distal end 234 can have a point. The cutter can have a cutter lumen 242 and a clear diameter 260.

[0054] The drive shaft can be constructed using any structure known to those skilled in the art that satisfies the axial, bending, and torsional stiffness requirements. In some embodiments, for example, the drive shaft includes a distal end and a proximal end, the distal end connected to or attached to the cutter, and the proximal end connected to a rotatable element, such as a gear attached to a motor or attached to the motor itself. The drive shaft may also be driven by a motor within the handle. The drive shaft can be constructed using a metal braid and / or one or more metal coils, and one or more portions of the drive shaft embedded in a polymer. In some embodiments, the polymer may include PEBAX, polyurethane, polyethylene, fluoropolymer, parylene, polyimide, PEEK, PET, or a combination thereof. In some variations, the drive shaft may comprise a rigid material, such as plastic, that is made flexible by incorporating a helical relief or groove. During a procedure, the motor drives the gear to rotate the drive shaft and cutter, cutting tissue within the target lesion.

[0055] Those skilled in the art will appreciate that the "clear diameter" of a blood vessel can be used to refer to the diameter of the lumen of a blood vessel after the cutter portion of an atherectomy device has passed through the lumen of the blood vessel. Because blood vessels are often elastic, the clear diameter 260 of the lumen of the blood vessel may or may not be equal to the diameter of the cutter 230. The clear diameter 260 of the cutter 230 may be larger than the outer diameter of the flexible drive shaft 250. In some embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible sheath. And, in some embodiments, the clear diameter 260 of the lumen is smaller than the diameter of the body of the cutter 230.

[0056] Table 1, for example, lists example arterial lumen diameters in mm starting from the aorta and down the human leg. Peripheral vascular disease of the legs is one example of a condition that can be treated using the atherectomy devices taught herein.

[0057] [Table 1]

[0058] The superior femoral artery is located approximately in the center of the femur and generally has a diameter of approximately 5 to 7 mm, or approximately 0.2 to 0.25 inches. As the artery descends below the knee, the diameter of the popliteal artery is typically approximately 4 to 4.5 mm (0.157 to 0.177 inches), decreasing to approximately 3.5 mm (0.137 inches) as it progresses toward the subject's foot. The popliteal artery again branches into the anterior tibial artery and tibiofibular trunk, which further decrease in diameter to approximately 3.0 mm, then to approximately 2.5 mm, or approximately 0.118 to 0.098 inches. The tibiofibular trunk further subdivides into the posterior tibial artery and peroneal artery, which further decrease in diameter to approximately 2.0 mm (0.078 inches). Generally speaking, the diameter of peripheral arteries in the leg can typically vary from approximately 2 mm to approximately 7 mm. Any of these blood vessels may contain plaque and may be a target area for the atherectomy devices taught herein. For example, coronary arteries are approximately 3 mm in size and vary in diameter from 2.5 to 4.5 mm, making the coronary arteries a promising target area for the atherectomy devices taught herein.

[0059] While it may seem reasonable to simply increase the cutter diameter for larger vessels, those skilled in the art will appreciate that cutter diameter may also be limited by physical complications of the patient's anatomy. For example, complications may arise during surgery due to bleeding from arterial puncture access, tortuous vessels, varying vessel sizes, etc. The cutter diameter may range from about 0.70 mm to about 2.20 mm in some embodiments, from 1.00 mm to 2.20 mm in some embodiments, from 1.20 mm to 2.20 mm in some embodiments, from 1.40 mm to 2.20 mm in some embodiments, from 1.50 mm to 2.20 mm in some embodiments, or any range therein in 0.10 mm increments. In some embodiments, the cutter diameter can be approximately 0.90 mm, 1.00 mm, 1.10 mm, 1.20 mm, 1.30 mm, 1.40 mm, 1.50 mm, 1.60 mm, 1.70 mm, 1.80 mm, 1.90 mm, 2.00 mm, 2.10 mm, 2.20 mm, 2.30 mm, or any diameter within that range, or ranges therein in 0.05 mm increments. This is important because the diameter of the vessel lumen can be very small or very large; a vessel with a diameter of 1.00 mm is too tight for the cutter, and in some embodiments, a vessel with a diameter greater than approximately 2.30 mm is becoming larger than the cutter can handle. Those skilled in the art will recognize that eccentric cutting allows for cutting areas larger than the diameter of the cutter assembly without requiring additional cutters or replacement with other, larger tools for removal. The cutter can be offset from the center in larger vessels to remove lumens larger than the cutter diameter.

[0060] Those skilled in the art will also understand that the length of the cutter may need to be limited to achieve the necessary maneuverability. Those skilled in the art will understand that the size of the cutter may be any size known in the art to be suitable for a particular treatment. In some embodiments, the length of the cutter may be in the range of about 0.50 mm to about 3.00 mm, about 0.60 mm to about 2.80 mm, about 0.80 mm to about 2.60 mm, about 1.00 mm to about 2.40 mm, about 1.00 mm to about 1.00 mm, about 1 mm to about 2.20 mm, about 1.00 mm to about 2.00 mm, about 1.20 mm to about 1.80 mm, or any range therein in 0.10 mm increments.

[0061] Atherectomy device 200 further includes a drive assembly for driving cutter 230. The drive assembly can have a flexible drive shaft 250 including a longitudinal axis having a central axis that can coincide with central axis 205 of atherectomy device 200. Flexible drive shaft 250 can further have a proximal portion with a proximal end (not shown), a distal end 252, an outer surface 254, and a distal portion with a drive shaft lumen 256, wherein distal end 252 of flexible drive shaft 250 has a fixed connection with cutter 230. Flexible drive shaft 250 can be rotatably translatable with lumen 221 of flexible sheath 215. Drive shaft 250 can extend to a drive engine located outside of the subject undergoing atherectomy, which in some embodiments is driven by an electric engine or in some embodiments is driven by an air compressor, and drive shaft 250 can be operably connected to a handle (not shown) at the proximal end of the atherectomy device for control by a user. The drive assembly can also include a positive displacement pump that pumps from a distal portion of drive shaft 250 adjacent to helical groove 238 at the proximal end of cutter 230. In some embodiments, the positive displacement pump extends from the distal portion of drive shaft 250 to a proximal portion of drive shaft 250 to pump cut pieces of arterial plaque out of the blood vessel.

[0062] Those skilled in the art will understand that the subject is a patient undergoing atherectomy. The terms "subject" and "patient" can be used interchangeably and refer to animals such as mammals, including but not limited to non-primates such as cows, pigs, horses, cats, dogs, rabbits, rats and mice, and primates such as monkeys or humans. In some embodiments, the subject can also be a corpse or part of a corpse.

[0063] The flexible drive shaft 250 can be longer than the flexible sheath 215 to allow reversible extension and retraction 270 of the drive assembly from the lumen 221 of the flexible sheath 215 at the distal end 252 of the flexible sheath 215. The guidewire lumen can include a cutter lumen 242 and a drive shaft lumen 256. The bending stiffness of the drive shaft 250 remains the same between the collapsed and expanded states of the device, but as the drive shaft extends and retracts 270 from the flexible sheath 215, the bending motion 290 increases. Thus, the amount of available bending motion 290 is greater in FIG. 2A than in FIG. 2B, and the ease of bending motion 290 is greater in FIG. 2A than in FIG. 2B due to the length of the drive shaft that is extended and retracted in FIG. 2A as opposed to the length of the drive shaft that is exposed in FIG. 2B. We have discovered that as the amount and ease of bending motion 290 increases with extension and retraction 270, it becomes easier for the cutter 230 to move through the artery.

[0064] In some embodiments, the cutter can be operably attached to the drive shaft using a friction fitting such that the drive shaft can slide over the base of the cutter when engaging plaque and meeting a maximum torque limit. And, in some embodiments, the positive displacement pump can be a screw pump 280, also referred to in some embodiments as an Archimedes screw. The positive displacement pump can be attached to the outer surface 254 of the drive shaft 250, with the distal end of the screw pump adjacent the helical groove 238 in the proximal end 232 of the cutter 230 to transport the severed plaque fragments from the cutter in a distal-to-proximal direction to the proximal end of the atherectomy device for removing the severed plaque from the subject.

[0065] FIG. 3 illustrates an automatically activatable, telescoping atherectomy device, according to some embodiments. Atherectomy device 300 can have, for example, a screw pump 380 in operative contact with cutter 330. Screw pump 380 can extend beyond flexible sheath 315 and be exposed for contact with the vessel lumen wall (not shown) during use of the atherectomy device within the vessel lumen, often potentially contacting plaque remaining on the lumen wall. In some embodiments, screw pump 380 can be right-handed (as shown) when cutter 330 is rotated in a right direction 390; and in some embodiments, screw pump 380 can be left-handed (opposite as shown) when cutter 330 is rotated in a left direction (opposite direction from 390). In this manner, a right-handed cutter is fitted with a right-handed thread pump, and a left-handed cutter is fitted with a left-handed thread pump, allowing the thread pump to assist in driving atherectomy device 300 along guidewire 310 and through the lumen of the vessel as it cuts vascular plaque within the lumen. Those skilled in the art will appreciate that an automatic drive device can provide significant value by reducing the force required by the surgeon, for example, during operation of the device. The automatic drive can be full or partial, meaning that in some embodiments, the device can eliminate the need for the surgeon to push on the device during the procedure, and in some embodiments, it reduces the pressure required from the surgeon during the procedure. Those skilled in the art of atherectomy will appreciate that pushing can bend, break, or clog the device, and / or the patient can suffer complications from perforation of the vessel being treated, as well as perforation of the tissue surrounding the vessel being treated.

[0066] The self-actuating features of the atherectomy devices taught herein can reduce the pressure required by the surgeon to perform the procedure. In some embodiments, the pressure required by the surgeon to perform the atherectomy can be reduced by 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, or any amount or range of 1% increments therein. In some embodiments, the pressure required by the surgeon performing the atherectomy can be reduced by an amount ranging from about 25% to about 100%, about 30% to about 100%, about 35% to about 100%, about 40% to about 100%, about 45% to about 100%, about 50% to about 100%, about 60% to about 100%, about 65% to about 100%, about 70% to about 100%, about 75% to about 100%, about 80% to about 100%, about 85% to about 100%, about 90% to about 100%, about 95% to about 100%, or any range of amounts in 1% increments therein. Similarly, in some embodiments, the pressure required by the surgeon performing the atherectomy can be reduced by an amount ranging from about 25% to about 95%, about 30% to about 90%, about 35% to about 85%, about 40% to about 80%, about 45% to about 75%, about 50% to about 85%, about 70%, about 60% to about 100%, about 65% to about 100%, about 70% to about 100%, about 75% to about 100%, about 80% to about 100%, about 85% to about 100%, about 90% to about 100%, about 95% to about 100%, or any range of 1% increments therein. Similarly, in some embodiments, the pressure required by the surgeon performing the atherectomy can be reduced by an amount ranging from about 25% to about 50%, about 50% to about 100%, or any range of 1% increments therein. Similarly, in some embodiments, the pressure required by the surgeon performing the atherectomy can be reduced by at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least any range therein in 1% increments.

[0067] In some embodiments, the surgeon may need to apply negative pressure, e.g., holding or pulling without pushing, to help control the cutting of the lesion. It should be understood that in some embodiments, the negative pressure may be 1%, 5%, 10%, 15%, 20%, or 25% negative, or any amount therein. Such negative pressure may slow the advancement rate of the cutting, stop the cutting, or move the cutting in a direction opposite to the automatic drive direction of the cutter.

[0068] Those skilled in the art will appreciate that atherectomy devices provide the versatility and maneuverability needed in the art for tortuous vessels. When plaque is located in a tortuous vessel or occluding an eccentric portion of the vessel passageway, eccentric cutting of the tissue can be useful for maneuvering the cutting head to remove the plaque. Atherectomy devices have existed that incorporate mechanisms that can create a curvature at the distal end of the device by pulling on "tendons" that pull the distal end of the device laterally. These devices suffer from the problem of imbalances in stress along the long axis of the atherectomy device, resulting in a "snapback" or "whip" action of the device. The devices provided herein provide eccentric cutting without the "snapback" or "whip" caused by these previously known mechanisms.

[0069] 4A-4D illustrate a telescoping atherectomy device that can further include a reversibly expandable lateral push member at the distal end of the flexible sheath, where expansion of the lateral push member induces curvature, according to some embodiments. As shown in FIG. 4A, telescoping atherectomy device 400 can further include a reversibly expandable lateral push member 444 at the distal end of flexible sheath 415, where push member 444 forms a protrusion lateral to the central axis of the atherectomy device. Lateral push member 444 can have a proximal portion with a proximal end, a distal portion with a distal end, and a reversibly expandable portion having a collapsed state (as shown in FIG. 4A) and an expanded state (as shown in FIGS. 4B and 4C). The protrusion can be rotated any amount or range from 1 to 360 degrees relative to the lesion, for example, to reach a desired target area within a blood vessel.

[0070] The lateral pusher member can be made of any material known to those skilled in the art to be suitable. For example, the lateral pusher member can be made of a biocompatible, flexible metal, such as a titanium alloy, such as nickel titanium. In some embodiments, the lateral pusher member can be made of a polymer, such as PEEK, polyimide, or nylon. The length of the truss or ribbon can be designed to provide any desired projection. For example, the length of the truss can vary from 1 mm to 100 mm in some embodiments, from 10 mm to 30 mm in some embodiments, from 10 mm to 40 mm in some embodiments, from 10 mm to 50 mm in some embodiments, from 20 mm to 60 mm in some embodiments, from 20 mm to 80 mm in some embodiments, or any range therein in 1 mm increments. In some embodiments, the length of the truss can be 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 100 mm, or any range therein in 1 mm increments.

[0071] The reversibly expandable portion has trusses 488 that expand and contract the reversibly expandable lateral pusher members 444 by applying an axial force to the lateral pusher members 444. In some embodiments, the trusses may be referred to as "ribbons." A proximal end of the lateral pusher members 444 is operatively connected to the flexible sheath 415, and a distal end of the lateral pusher members 444 is operatively connected to the cutter 430. The operable connections with flexible sheath 415 and cutter 430 can each be configured to receive an axial force such that application of a proximal-to-distal axial force collapses lateral push member 444, and when an axial force is applied in a desired direction by reversible extension and retraction of flexible drive shaft 450 within flexible sheath 415, (i) an axial force is applied along the axis of flexible drive shaft 450 from cutter 430 to flexible sheath 415, and (ii) application of a distal-to-proximal axial force is transmitted through and expands lateral push member 444. Lateral push member 444 has a contracted 445c and an expanded effective radius 445e.

[0072] In some embodiments, proximal-to-distal and distal-to-proximal forces are received by the lateral push member 444 at a proximal collar 455 at a proximal portion of the lateral push member 444 and at a distal collar 466 at a distal portion of the lateral push member 444. Additionally, the operable connection between the lateral push member 444 and the cutter 430 can be configured as a rotatably translatable connection, which can facilitate rotation of the cutter 430 and flexible drive shaft 450 without rotating or imparting undesirable torque to the distal end of the lateral push member 444 during operation of the atherectomy device 400.

[0073] The axial force can be applied using any structure that applies force along the central axis of the drive shaft, for example, a centralized member such as a tendon, to avoid loading the atherectomy device and resulting in snapback or whip force release along the long axis of the device. In some embodiments, the structure that provides the axial force can be a drive shaft that is already positioned at the center of the device, for example, concentric within a sheath. Thus, in some embodiments, a method of expanding a lateral pushing member includes applying a distal-to-proximal force to a distal portion of the lateral pushing member, the force being applied along the central axis of the atherectomy device, the central axis of the drive shaft, or the central axis of the sheath.

[0074] Contact of the lateral pushing member 444 with the vessel wall pushes the cutter 430 laterally away from the central axis of the vessel lumen, opposite the direction of expansion of the truss 488. The magnitude of deflection of the cutter 430 is adjustable and controllable.

[0075] As shown in FIG. 4B , the expansion of truss 488 on lateral push member 444 deflects cutter 430 of atherectomy device 400 toward vessel lumen wall 499, which is on the opposite side of vessel lumen wall 499 from the force that is exerted from the expansion of truss 488.

[0076] One or more expandable trusses can be used. In some embodiments, there is a single truss. In some embodiments, there are two trusses. In some embodiments, there are three trusses. In some embodiments, there are four trusses. In some embodiments, there are at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 trusses. The trusses can be pre-shaped to create a biased curve or angle that protrudes outward from the central axis of the device. That is, in some embodiments, the trusses have a shape memory that allows the trusses to remain in a collapsed state, and the expanded state is achieved by applying a force to the truss, for example, by pulling on a central tendon or drive shaft. In some embodiments, the trusses have a shape memory that allows the trusses to remain in an expanded state, and the collapsed state is maintained by holding the truss in a collapsed state, and the expanded state is achieved by releasing the holding force and returning the shape memory to the truss. The trusses can be any shape, and in some embodiments, there can be a single truss or multiple trusses. In some embodiments, the trusses can form a basket shape. In some embodiments, rather than using a truss, a balloon can be inflated to bias the cutter. For example, the truss may be an arched or angled ribbon that helps to stabilize, for example, a flexible drive shaft.

[0077] The eccentric cutting of the devices provided herein can provide safe, clean cuts in tortuous and non-tortuous vessels, as well as eccentric lesions. The lateral push member 444 enhances safety because, without such lateral protrusion, the cutter assembly is biased to move toward the outside of the vessel curvature, which can result in inadvertently cutting the vessel wall rather than the target plaque on the inside of the vessel. The lateral push member 444 addresses this issue by correcting the bias by expanding the truss 488 toward the outside of the vessel curvature, pushing the cutter laterally to the opposite side of the vessel, achieving a more controlled, effective, and safer cut than conventional cutters. For example, when debulking an eccentric lesion, adjustable lateral push allows the cutter assembly to specifically target the side of the vessel with a large amount of stenotic material to achieve an eccentric cut.

[0078] In some embodiments, the effective cutting diameter may be approximately half the diameter of the cutter plus the lateral extent of the protrusion from the central axis of the cutter. For example, if the cutter diameter is 2.2 mm and the protrusion protrudes 3.0 mm from the axis of the cutter, the effective cutting diameter will be 4.1 mm. As can be seen, eccentric cutting results in a cutting area that is much larger than the diameter of the cutter.

[0079] In some embodiments, the amount of protrusion (from slight to maximum protrusion) is adjustable. For example, the distance between the two ends or collars of the lateral pusher member can be adjusted. That is, the distance between the two ends or collars of the lateral pusher member can be set as desired. In some embodiments, the distance between the collars is increased to reduce truss expansion and therefore cutter deflection. Similarly, decreasing the distance between the collars increases truss expansion and cutter deflection. One skilled in the art will appreciate that a dial, knob, button, or other actuator on the device can provide a device user with a measure of the distance between the collars of the lateral pusher member 444. In some embodiments, increasing the distance the drive shaft travels relative to the sheath increases truss 488 expansion. Similarly, in some embodiments, decreasing the distance the drive shaft travels relative to the sheath decreases truss 488 expansion.

[0080] In some embodiments, the proximal portion or end of the lateral pusher member 444 will be in fixed contact with the distal portion or end of the sheath, and the distal portion or end of the drive shaft will be rotatably and translationally connected to the cutter; with a component proximal to the cutter including a race and step that allows the cutter to rotate despite the presence of the drive shaft. In some embodiments, the race may be referred to as a "bearing surface." The component may be, for example, a fixed race or bearing; as a result, the lateral pusher member does not rotate, but the drive shaft rotates freely at the distal portion or end of the lateral pusher member.

[0081] Interestingly, it has been discovered that the relative bending stiffness of the drive shaft 450 compared to the truss 488 also helps control which portion of the cutter 430 contacts and severs plaque on the vessel lumen wall 499. For example, if the bending stiffness of the drive shaft 450 is greater than the bending stiffness of the truss 488, expansion of the truss 488 is unlikely to cause deformation 490 of the drive shaft 450, and contact between the cutter 430 and the vessel lumen wall 499 will occur further toward the body of the cutter 430. However, if the bending stiffness of the drive shaft 450 is less than the bending stiffness of the truss 488, the drive shaft 450 is expected to deform, and contact between the cutter 430 and the vessel lumen wall 499 will begin to occur further toward the distal end of the cutter 430.

[0082] In some embodiments, the flexible atherectomy device F D The bending stiffness of the distal part of the lateral pushing member F LPM In some embodiments, the flexible atherectomy device F D The bending stiffness of the distal part of the lateral pushing member F LPM In some embodiments, the bending stiffness F of the distal portion of the flexible atherectomy device is equal to or greater than D is the lateral pushing member F LPM The bending stiffness is greater than that of

[0083] F D is F LPM In some embodiments, F may be reduced by an amount in the range of 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, or any amount or range in 1% increments therein. D is F LPM The amount of F may be reduced by an amount ranging from about 25% to about 80%, about 30% to about 75%, about 35% to about 75%, about 40% to about 75%, about 45% to about 75%, about 50% to about 75%, about 60% to about 75%, about 65% to about 75%, about 70% to about 75%, or any range of amounts in 1% increments therein.D is F LPM can be reduced by an amount in the range of at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or any range or amount therein in 1% increments.

[0084] Given this information, one skilled in the art will appreciate that the amount of deflection can be selected by selecting the relative ratio of the bending stiffness of the drive shaft 450 and the truss 488, thereby providing the user of the atherectomy device with more control over the cutter. Thus, in some embodiments, the atherectomy device 400 can be designed so that the bending stiffness of the truss 488 is greater than the bending stiffness of the drive shaft 450 to obtain the desired amount of deflection of the drive shaft and direct the desired surface of the cutter 430 against the vessel lumen wall 499. In some embodiments, the bending stiffness of the drive shaft can be greater than or equal to the bending stiffness of the truss 488 to avoid deflection of the drive shaft. One skilled in the art will appreciate that there are ways to vary the bending stiffness of the drive shaft. The stiffness or flexibility of the drive shaft can be adjusted, for example, by changing the orientation or relationship of the filaments that make up the drive shaft. In some embodiments, to increase bending stiffness, the filaments on the shaft can be bonded with a stiffer material, or the bending stiffness can be increased (or decreased) by increasing (or decreasing) the size of the filaments.

[0085] The lateral pushing member can be designed to expand into a curved ridge. In some embodiments, the lateral pushing member can be folded to have an effective radius 445c that is equal to or less than the radius of the sheath. In some embodiments, the lateral pushing member can be folded to have an effective radius 445c that is equal to or less than the radius of the cutter. In some embodiments, the lateral pushing member is folded to have an effective radius 445c that is equal to or less than the radius of the cutter's clear diameter to facilitate movement of the device within the vessel.

[0086] Torsional stresses on the lateral pusher members 444 are a design consideration. To mitigate torsional stress concerns in the lateral pusher members 444, the torsional stresses on the distal ends of the lateral pusher members can be reduced, the torsional stiffness of the lateral pusher members can be increased, or both of these design changes can be implemented.

[0087] 4C provides an alternative operable connection between the cutter and the lateral push member to address torsional stresses, according to some embodiments. In some embodiments, the distal race 477 is fixed and serves as a bearing race for the rotary cutter 430. However, in some embodiments, the distal race 477 rotates while in contact with the rotary cutter 430 and the distal collar 466 of the lateral push member 444. Thus, the distal race 477 is free to rotate, further reducing torsional stresses on the lateral push member 444. In some embodiments, the distal race 477 can be made of a low-friction material, such as Teflon®.

[0088] FIG. 4D illustrates how a curvature can be induced in the distal portion of the atherectomy device as deformation 490. As discussed herein, the relative bending stiffness of the distal portion of drive shaft 450 and the lateral pusher member can induce the formation of a curvature when a force is applied to induce lateral expansion of truss 488, as described above, which also changes the orientation of cutter 430 within the vessel lumen (not shown). Deformation 490 can be restored to the straight position shown in FIG. 4B by extending or retracting drive shaft 450 from sheath 415. This realigns cutter 430 within the vessel lumen (not shown) from a position where the distal cutter is oriented to cut to a position where the sides of cutter 430 are oriented to cut.

[0089] It should be understood that the telescoping, self-driving, and lateral-pushing features are each distinct technical advantages. Therefore, the atherectomy device can be solely a self-driving atherectomy device, i.e., the device does not need to be telescopic or laterally pushed. In these embodiments, the components can be labeled the same as or similar to other embodiments taught herein, and the device can have a distal portion having a distal end, a proximal portion having a proximal end, a longitudinal axis having a central axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis. The device can include a flexible sheath having an outer diameter and a sheath lumen, a proximal end, a distal end, and a cutter having a body with multiple spiral grooves. The distal end of the cutter can have multiple cutting lips, a cutter lumen, and a point with a clear diameter. These devices can also include a drive assembly. The drive assembly can have a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, where the flexible drive shaft rotatably translates relative to the lumen of the flexible sheath. The drive assembly can also have a screw pump attached to the outer surface of the drive shaft and adjacent to the helical groove in the proximal end of the cutter. The screw pump can include a drive screw portion. In some embodiments, the drive screw portion can be the distal portion of the screw pump.

[0090] To be self-driving, for example, the drive screw portion can extend beyond the flexible sheath and be exposed to contact the vascular lumen during use of the atherectomy device. To effectively assist in driving the device through the vascular lumen, the drive screw should rotate in the same direction as the cutter. For example, if the cutter flutes spiral in the right direction, the drive screw should also spiral in the right direction. Similarly, if the cutter flutes spiral in the left direction, the drive screw should also spiral in the left direction. Thus, in some embodiments, when the cutter rotates in the right direction, the drive screw portion can be right-handed, and in some embodiments, when the cutter rotates in the left direction, the drive screw portion can be left-handed.

[0091] The relative sizes of the lumen, cutter, and drive screw can be designed to optimize the self-driving function. In these embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible drive shaft; and in some embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible sheath.

[0092] Of course, any of the self-actuating devices can include telescoping functionality, and its components can be labeled the same or similarly as other embodiments taught herein. For example, the flexible drive shaft of a self-actuating atherectomy device can be longer than the flexible sheath so that the drive assembly can be reversibly telescoped from the lumen of the flexible sheath at the distal end of the flexible sheath.

[0093] Additionally, any of the automated drive devices can include a reversibly expandable lateral pusher member, the components of which can be labeled the same or similarly as other embodiments taught herein. In some embodiments, the lateral pusher member can have a proximal end, a distal end, a collapsed state, and an expanded state, with the proximal end operatively connected to the flexible sheath and the distal end operatively connected to the cutter. The operative connection with the flexible sheath and the operative connection with the cutter can each be configured to receive an axial force (i) applied from the cutter along the axis of the flexible drive shaft to the flexible sheath, and (ii) transferred through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and retraction of the flexible drive shaft from the flexible sheath. Furthermore, in some embodiments, the operative connection with the cutter can be configured as a rotatably translatable connection, particularly the distal portion of the lateral pusher member, to facilitate rotation of the cutter and the flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device.

[0094] Similarly, the atherectomy device may be a lateral-pushing atherectomy device only, where the device does not require automatic actuation, and its components may be labeled the same or similarly as in other embodiments taught herein. However, it must be telescopic at least to the extent necessary for the lateral-pushing member to expand and collapse. In these embodiments, the device may have a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the longitudinal direction. The device may include a flexible sheath having an outer diameter and a sheath lumen. The device may have a cutter having a proximal end, a distal end, and a body with multiple helical grooves, a distal end point with multiple cutting lips, a cutter lumen, and a clear diameter; and a drive assembly. The drive assembly may have a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, where the flexible drive shaft is rotatably translatable relative to the lumen of the flexible sheath. The drive assembly may also include a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the helical groove in the proximal end of the cutter. The lateral pushing atherectomy device may also have a reversibly expandable lateral pushing member at the distal end of the flexible sheath.

[0095] The relative sizes of the lumen and cutter can be designed to optimize movement of the atherectomy device through the lumen. For example, the clear diameter of the cutter can be larger than the outer diameter of the flexible drive shaft. In some embodiments, the clear diameter of the cutter can be larger than the outer diameter of the flexible sheath. The sizes of the cutter lumen and drive shaft lumen can be configured to allow passage of a guidewire of a desired gauge, such that the guidewire lumen can include the cutter lumen and the drive shaft lumen.

[0096] In some embodiments, the lateral pusher member can have a proximal portion having a proximal end, a distal portion having a distal end, a collapsed state, and an expanded state, the proximal end having an operable connection with the flexible sheath, and the distal end having an operable connection with the cutter. In some embodiments, the operable connection with the flexible sheath and the operable connection with the cutter can each be configured to receive an axial force (i) applied from the cutter along the axis of the flexible drive shaft to the flexible sheath, and (ii) transferred through the lateral pusher member during contraction and expansion of the lateral pusher member by reversibly extending and retracting the flexible drive shaft from the flexible sheath. And, in some embodiments, the operable connection with the cutter can be configured as a rotatably translatable connection to facilitate rotation of the cutter and the flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device.

[0097] In some embodiments, the atherectomy device may be telescoping, and its components may be labeled the same as or similar to other embodiments taught herein. That is, the flexible drive shaft of a lateral push atherectomy device may be longer than the length required for expansion of the lateral push member. The flexible drive shaft of a lateral push atherectomy device may be longer than the flexible sheath so that the drive assembly can be reversibly extended and retracted from the lumen of the flexible sheath at the distal end of the flexible sheath.

[0098] Also, in some embodiments, the lateral push atherectomy device may be self-driven, and its components may be labeled the same or similarly to other embodiments taught herein. That is, the lateral push atherectomy device may include a drive screw attached to the outer surface of the distal end of the drive shaft and adjacent to the screw pump at the distal end of the screw pump. The drive screw may be part of the screw pump and may extend beyond the flexible sheath and be exposed for contact with the vessel lumen during use. In some embodiments, when the cutter rotates in a right direction, the drive screw may be right-handed, and in some embodiments, when the cutter rotates in a left-handed direction, the drive screw may be left-handed.

[0099] The inventors have discovered that the ratios of (i) the dimensions and (ii) the stiffness of the atherectomy devices taught herein each contribute to the performance and behavior of the device, the ease of cutter advancement, the ability to rotate the atherectomy device, the ability to steer the device, the relative amount of plaque removed, etc. Table 2 shows example dimensions of the components of the atherectomy device, and Table 3 shows example ratios of dimensions of the components of the atherectomy device. [Table 2] [Table 3] "Cutter OD" is the maximum outer diameter of the cutter. "Screw Pump OD" is the outer diameter of the drive shaft plus two diameters of the screw pump wire that surrounds the drive shaft. "Drive shaft OD" is the outside diameter of the drive shaft, not including the two diameters of the screw pump wires. "Sheath ID or OD" is the inside or outside diameter of the flexible tube, or "sheath." "Minimum front edge OD" is the outer diameter of the most distal end of a cutting edge. "Guidewire Lumen ID" is the inner diameter of the guidewire lumen. "Lateral pushing member OD" refers to the outer diameter of the lateral pushing member, which may be in a folded or unfolded state.

[0100] It has been found that the relative sizes of the device components significantly affect device movement within the vascular lumen. In some embodiments, the cutter diameter should be at least 30% larger than the drive shaft diameter. The ratio of cutter diameter to drive shaft diameter can be in the range of 1.3 to 2.0, 1.3 to 1.8, 1.3 to 1.7, 1.3 to 1.6, 1.3 to 1.5, 1.3 to 1.4, or any range therein. In some embodiments, the ratio of cutter diameter to drive shaft diameter can be 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5, or any range therein in 0.0.5 increments. However, in some embodiments, the cutter diameter is 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, or any percentage in 0.5% increments therein, greater than the diameter of the drive shaft.

[0101] In some embodiments, the cutter diameter should be at least 20% larger than the sheath diameter. The ratio of cutter diameter to sheath diameter can be in the range of 1.2 to 2.0 in some embodiments, 1.2 to 1.8 in some embodiments, 1.2 to 1.7 in some embodiments, 1.2 to 1.6 in some embodiments, 1.2 to 1.5 in some embodiments, 1.2 to 1.4 in some embodiments, 1.2 to 2.0 in some embodiments, or any range therein. In some embodiments, the ratio of cutter diameter to drive shaft diameter can be 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5, or in some embodiments, any ratio therein in increments of 0.05. However, in some embodiments, the cutter diameter is 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, or any percentage in 0.5% increments therein that is greater than the sheath diameter.

[0102] Given the teachings herein, one skilled in the art can design the drive shaft, sheath, and, in some embodiments, the lateral pushing member to have desirable mechanical and physical properties for an atherectomy procedure. In some embodiments, the mechanical and physical properties of the device provide sufficient strength to push the cutter forward during the procedure, yet sufficient flexibility to manipulate the cutter within tortuous vessels and align it with a guidewire.

[0103] Those skilled in the art will appreciate that the techniques provided herein can include component bending stiffness design selection that promotes improved performance, maneuverability, and reliability of an atherectomy device. Bending stiffness is a measure of deformability expressed in units of N / mm. For example, bending stiffness may be described as the ability of a component to bend in response to an applied bending force without breaking or deforming the component. For example, in some embodiments, those skilled in the art can select the bending stiffness of the drive shaft, sheath, or both, for maneuverability of the atherectomy device to follow a guidewire around tortuous blood vessels.

[0104] Those skilled in the art will also appreciate that the technology provided herein can include selecting the torsional stiffness design of components to facilitate improved performance through torsional strength. Torsional stiffness is the resistance to twisting due to torsional loads, allowing a component to transmit a rotational load (torque) without untwisting, overtwisting, or deforming, and is measured in units of N*mm / rad. For example, in some embodiments, those skilled in the art can select the torsional stiffness of the drive shaft, the lateral pushing member, or both, to ensure that the cutter can cut against resistance from the plaque without damaging the drive shaft, and the lateral pushing member does not rotate, or at least rotates only a limited amount, to avoid failure of the lateral pushing member device during atherectomy.

[0105] Those skilled in the art will also appreciate that the techniques provided herein can include component axial tensile stiffness design selection to facilitate improved performance through better response to the push and pull of the atherectomy device. Axial tensile stiffness is the resistance to elongation or contraction along the length of a component under axial load, measured in N / mm. Key components that should include axial tensile stiffness design selection include the drive shaft, sheath, and lateral push member.

[0106] Tables 4 and 5 provide examples of bending, torsional, and axial stiffness of components of the atherectomy devices taught herein, as well as ratios of the relative stiffness of the components. [Table 4] [Table 5]

[0107] In some embodiments, the bending stiffness of the sheath should be at least three times greater than the drive shaft. The ratio of the bending stiffness of the drive shaft to the bending stiffness of the sheath can be in the range of 0.03 to 0.40 in some embodiments, 0.05 to 0.30 in some embodiments, 0.05 to 0.25 in some embodiments, 0.06 to 0.30 in some embodiments, or any range therein. In some embodiments, the ratio of the bending stiffness of the drive shaft to the bending stiffness of the sheath can be 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, or any ratio or range therein in increments of 0.005, in some embodiments. However, in some embodiments, the bending stiffness of the sheath is 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, or any range therein, greater than the bending stiffness of the drive shaft.

[0108] 5A-5C illustrate a compressible sleeve that can be used to increase the torsional stiffness of a lateral pusher member and form a shield for a positive displacement pump, and, according to some embodiments, increased pump efficiency with improved removal of cut particles from a container. Figures 5A and 5B show compressible sleeve 500 having a proximal portion 505, a distal portion 510, and a compressible portion 515 having a helically wound band with gaps between each helix, the pitch between each helix, and the width and thickness of the helically wound band. In some embodiments, the helically wound band of compressible portion 515 is integral with proximal portion 505 and distal portion 505.

[0109] 5C illustrates deformation 590 in the distal portion of the atherectomy device. As described herein, the relative bending stiffness of the distal portion of the drive shaft 550 and the lateral pushing member truss 588 can induce the formation of a bend 590 when a force is applied to induce lateral expansion of the truss 588, as described above, which also alters the orientation of the cutter 630 within the vessel lumen (not shown). The compressible sleeve 500 compresses the helically wound band of the compressible portion 515 during the lateral expansion of the truss 588 and during the generation of deformation 590 in the drive shaft and compressible sleeve 500. Thus, according to some embodiments, the expansion of the lateral pushing member truss 588 can induce a bend 590 in the distal portion of the atherectomy device.

[0110] FIG. 5D illustrates the release of deformation 590 in the distal portion of the atherectomy device, straightening the distal portion of the atherectomy device. Drive shaft 550 retracts from a sheath (not shown), relieving the force between drive shaft 550 and truss 588 and straightening drive shaft 550 and truss 588. This realigns cutter 530 within the vessel lumen (not shown) from a position where the distal portion of cutter 530 is oriented to cut to a position where the sides of cutter 530 are oriented to cut. Compressible sleeve 500 releases the helically wound band of compressible portion 515 from deformation 590 caused by the lateral expansion of truss 588, returning it to its original straight position as shown in FIG. 5D. Thus, according to some embodiments, the expansion of truss 588 of the lateral pushing member releases deformation 590 in the distal portion of the atherectomy device, allowing it to return to its straight position.

[0111] The compressible sleeve 500 can be positioned outside the flexible drive shaft 550 and between the proximal and distal ends of the lateral push member such that the flexible drive shaft 550 rotates inside the compressible sleeve. As shown herein, there can be a collar at each end of the lateral push member, a proximal collar, and a distal collar, with the proximal portion 505 of the compressible sleeve 500 operably attached to the proximal collar of the lateral push member and the distal portion 510 of the compressible sleeve 500 operably attached to the distal collar of the lateral push member. The design of the compressible portion 515 allows the compressible sleeve 500 to bend or compress when the ribbons of the lateral push member are pushed outward from a flat state, while providing additional torsional stiffness between the proximal and distal collars of the lateral push member to handle torsional stresses on the lateral push member. In some embodiments, the distal and proximal collars of the lateral push member do not twist, or at least have reduced torsional motion, relative to each other. In some embodiments, the compressible sleeve 500 also serves as a cover for a positive displacement pump, also known as an Archimedes screw. Therefore, the compressible sleeve 500 can function as a safety shield while the Archimedes screw suctions cut plaque particles. It should be appreciated that providing a cover over the positive displacement pump mechanism can also assist the pump in removing particles by helping to retain particles in a fixed space. For example, in the case of a screw pump, the compressible sleeve is positioned in close proximity to the screw mechanism to retain plaque particles within the lumen of the compressible sleeve 500, helping the screw mechanism 580 more efficiently move the particles out of the treated blood vessel. Furthermore, the expansion truss 588 of the lateral pusher member requires the proximal and distal collars of the lateral pusher member to move closer together when compressing the compressible sleeve 500; compression occurs in the gaps between the helices of the compressible sleeve 500, allowing for shortening to occur.

[0112] The compressible sleeve 500 can be made of any suitable material known to those skilled in the art, with the choice of material determining, for example, the required bandwidth and thickness. In some embodiments, the compressible sleeve can be made of stainless steel, nitinol, other metal alloys, or polymers such as PEEK, polycarbonate, nylon, or polyimide.

[0113] Example dimensions for compressible sleeve 500 are listed in Table 6 for at least the vasculature of the lower extremities. [Table 6] [Table 7]

[0114] The stiffness and ratios of the drive shaft and compressible sleeve are shown in Tables 8 and 9. [Table 8]

[0115] In some embodiments, the bending stiffness of the drive shaft should be at least 50% greater than the drive compressible sleeve. The ratio of the bending stiffness of the drive shaft to the bending stiffness of the compressible sleeve can be in the range of 1.5 to 6.0 in some embodiments, 1.5 to 5.0 in some embodiments, 1.6 to 5.0 in some embodiments, 1.7 to 5.0 in some embodiments, or any range therein. In some embodiments, the ratio of the bending stiffness of the drive shaft to the bending stiffness of the compressible sleeve can be 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, or in some embodiments, any ratio or range therein in 0.1 increments. However, in some embodiments, the bending stiffness of the drive shaft is 2 times, 3 times, 4 times, 5 times, 6 times, or any amount in 0.1 increments, or any range therein, greater than the bending stiffness of the compressible sleeve.

[0116] Cutter performance may vary depending on factors including tissue type, for example, but any cutter known to one of ordinary skill in the art may be used with the atherectomy devices taught herein. Figures 6A and 6B illustrate other cutters that may be used in accordance with some embodiments. Both Figures 6A and 6B show a cutter 600 having a distal end 601, a proximal end 603, a lumen 605, and grooves 607. The cutter 600 in Figure 6A also has a burr portion 609, while the cutter 600 in Figure 6B has a hammer portion 611.

[0117] 6A has a burr portion 609 that can be secured onto the cutter. In some embodiments, the burr portion 609 can be monolithically integrally formed with the cutter. However, in some embodiments, the burr portion 609 can be operably attached to the cutter using a friction fit, allowing the burr to slide on the base of the cutter when engaging the plaque and meeting the maximum torque limit.

[0118] The cutter of Figure 6B, in some embodiments, has a hammer portion 611 that can be secured to a drive shaft. In some embodiments, the hammer portion 611 can be operably attached to the cutter using a friction fitting, which allows the hammer portion to slide on the drive shaft when engaging plaque and meeting a maximum torque limit. The hammer portion 611 has oscillating teeth 613 that contact the blade portion 612 to create an oscillating hammer effect on the plaque for cutting.

[0119] Atherectomy systems can also be assembled to include the atherectomy devices taught herein. In some embodiments, any of the atherectomy devices taught herein can be a system that includes an atherectomy device and a guidewire.

[0120] The atherectomy device is also useful in several methods of performing atherectomy in a subject. In some embodiments, the method includes creating an entry point in a vascular lumen of a subject; inserting the atherectomy device into the vascular lumen; The method can include extending and retracting the flexible drive shaft; severing the plaque from the lumen of the blood vessel using a cutter of the atherectomy device; ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the blood vessel of the subject.

[0121] In some embodiments, the method can include creating an entry point in a vascular lumen of the subject; inserting an atherectomy device into the vascular lumen; driving the atherectomy device through the vascular lumen using an exposed drive screw; severing plaque from the vascular lumen using a cutter of the atherectomy device; ejecting the severed plaque from the vascular lumen using a positive displacement pump; and removing the atherectomy device from the vascular lumen of the subject.

[0122] Similarly, in some embodiments, the method can include creating an entry point in the lumen of a target blood vessel; inserting an atherectomy device into the lumen of the blood vessel; pushing a distal portion of the atherectomy device laterally within the lumen of the blood vessel, the pushing expanding a lateral pushing member; severing plaque from the lumen of the blood vessel with a cutter of the atherectomy device; ejecting the severed plaque from the lumen of the blood vessel with a positive displacement pump; and removing the atherectomy device from the lumen of the target blood vessel.

[0123] Similarly, in some embodiments, the method can include grinding the plaque with a burr, such as burr portion 609 in Figure 6A. The burr can have ridges, such as burr portion 609, or can be an abrasive surface with a desired "grit."

[0124] Similarly, in some embodiments, the method can include hammering the plaque using a hammer cutting blade configuration, such as, for example, cutting portion 612 of the cutter in FIG. 6B.

[0125] Those skilled in the art will appreciate that the above steps represent merely an example of a sequence of steps that may be used in atherectomy. In a simple embodiment, for example, the method may include the following: inserting an atherectomy device as taught herein into a vascular lumen of a subject, the atherectomy device having a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing longitudinally through the device; a flexible sheath having an outer diameter and a sheath lumen; a cutter having a proximal end, a distal end, and a body with a plurality of spiral grooves, a point at the distal end with a plurality of cutting lips, a cutter lumen, and a clear diameter; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; and a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the spiral grooves in the proximal end of the cutter; the inserting step including the drive assembly; advancing a cutter into a target area of ​​a subject's vascular lumen, the advancing comprising: telescoping the distal end of the flexible drive shaft away from the distal end of the flexible sheath to increase flexibility of the atherectomy device within the vessel lumen; automatically driving the cutter into the target area, the automatically driving including rotating a screw at the distal end of the flexible drive shaft; pushing the distal end of the flexible sheath, the distal end of the flexible drive shaft, and the cutter laterally toward the wall of the vessel lumen; or the advancing step including combinations thereof; severing the plaque from the wall of the vessel lumen, the severing including rotating a cutter; and removing plaque from the vessel lumen using a positive displacement pump; and Removing the atherectomy device from the subject The method comprising:

[0126] It should be appreciated that the devices, systems, and methods provided herein enable enhanced functionality during an atherectomy procedure. In some embodiments, methods of steering a cutting head are provided, which can include redirecting a distal end of a flexible atherectomy device. In some embodiments, the redirecting can include: (i) Extending the push member, where extension involves pulling the concentric "member"; (ii) The expansion causes the lateral pushing member to expand and push the distal end of the flexible atherectomy device to bend / curve.

[0127] The converging "member" could be, for example, a flexible drive shaft or a converging tendon, meaning that it is freely translatable axially and longitudinally, possibly forming a guidewire lumen in some embodiments. Truly surprising and unexpected advantages have been achieved by converging pulling on or near the central axis of the atherectomy device, the central axis of the sheath, and / or the central axis of the drive shaft. Repeating this surprising result provides a conventional telescoping, self-driving, and laterally pushing atherectomy device, each having a flexible sheath, a cutter with a helical groove, and a drive assembly. The drive assembly can have a flexible drive shaft that rotates and translates with the lumen of the flexible sheath, a positive displacement pump that initiates pumping at the distal end of the drive shaft adjacent to the helical groove at the proximal end of the cutter, and the flexible drive shaft can be longer than the flexible sheath to allow the drive assembly to be reversibly extended and retracted from the lumen of the flexible sheath. The positive displacement pump can be a screw pump having a drive screw portion extending beyond an exposed flexible sheath to contact the vessel lumen for self-actuation, and the device can have a reversibly expandable lateral pushing member at the distal end of the flexible sheath for lateral pushing.

[0128] Hybrid cutters for removing hard, soft, and combined hard and soft tissue The cutting efficiency of each of the atherectomy devices taught herein can be improved by the design of the cutter. It should be understood that in some embodiments, the cutter may also be referred to as a "cutting head," "bit," "mill," or "end mill." Thus, a hybrid atherectomy cutter for cutting a combination of soft and hard plaques is provided.

[0129] Figures 7A-7C illustrate cutter features, including primary and secondary blades, grooves, helix angle, and guidewire lumen, according to some embodiments. As shown in Figure 7C, the cutter can include a proximal end, a distal end, and a longitudinal axis. Figure 7A is a perspective view of both the proximal and distal ends of the cutter, Figure 7B is a view of the distal end of a three-blade cutter, and Figure 7C is a side view of a four-blade cutter. As shown in Figure 7A, the cutter 700 can have a first primary cutting blade 705-1 and a second primary cutting blade 705-2, the first primary cutting blade 705-1 and the second primary cutting blade 705-2 extending helically along a radius from the distal end to the proximal end. Similarly, there is a first secondary cutting blade 710-1 and a second secondary cutting blade 710-2. Cutter 700 can have first and second spiral grooves 730 and 731, each of which has a helical angle 770 relative to longitudinal axis 701 and forms a spiral channel with a distal inlet 735 and a proximal outlet 737, the spiral channel being open at the distal and proximal ends to allow cut tissue to enter and exit the spiral channel, a feature of all cutters taught herein. Cutter 700 can also have a lumen 750 configured for passage of a guidewire (not shown). As shown in FIG. 7B, in some embodiments, cutter 700 can have a third spiral groove 733 in addition to a third primary cutting edge 705-3 and a third secondary cutting edge 710-3. As shown in FIG. 7C, in some embodiments, the cutter 700 can have a fourth primary cutting edge 705-4 and a fourth secondary cutting edge 710-4 (not shown), as well as a fourth spiral groove 734 (labeled but not visible in FIG. 7C).

[0130] The primary cutting blades can extend along the entire cutter and can be divided into three distinct portions: a proximal portion, a middle portion, and a distal portion in some embodiments. The proximal portion of each primary cutting blade can have a helical shape, e.g., in some embodiments, can follow a path along the clear diameter. The middle portion of each primary cutting blade can have a helical shape and can also follow the clear diameter. In some embodiments, the distal portion of each primary cutting blade can taper toward the distal end of the cutter.

[0131] In some embodiments, the secondary cutting edge may be shorter than the primary cutting edge. In some embodiments, the secondary cutting edge may be the same length as the primary cutting edge. In some embodiments, the secondary cutting edge is less than ½ the length of the primary cutting edge. In some embodiments, the secondary cutting edge is less than ¼ the length of the primary cutting edge. In some embodiments, the secondary cutting edge ranges from about 5% of the length of the primary cutting edge to about 45% of the length of the cutting edge. In some embodiments, the secondary cutting edge may be formed by the addition of facets, which may be in the form of two adjacent planes, Plane 1 and Plane 2, toward the distal end of the cutter.

[0132] In some embodiments, a secondary cutting edge can be positioned between each two primary cutting edges, with one facet being a first plane with a first side coincident with the primary cutting edges, and a second facet being a second plane with a second side coincident with the first plane.

[0133] In some embodiments, the secondary cutting edge may also taper toward the distal end of the cutter, similar to the distal portion of the primary cutting edge, hi some embodiments, both the secondary cutting edge and the primary cutting edge may decrease toward the distal end of the cutter.

[0134] In some embodiments, the distal-most portion of the secondary cutting blade and the distal-most portion of the primary cutting blade can function in a forward cut, creating a pathway for atherectomy in narrowed or completely occluded lesions. Furthermore, the forward cut achieved by the combination of the primary and secondary blades can sever plaque into smaller particles than can be achieved with conventional state-of-the-art atherectomy devices. In some embodiments, the helical profile of the primary blade provides continuous removal of debulked material by continuously moving tissue proximally during cutter operation.

[0135] 8A-8D illustrate features of a cutter taught herein, including cutting length, radius, and cutting diameter, according to some embodiments. As shown in FIGS. 8A-8D, the cutting length 820 of cutter 800 is defined by the distance from the proximal end to the distal end along longitudinal axis 801. The configuration of cutter 800 can have a radius 840 at the distal end, with radius 840 having an inner inflection point 841 and an outer inflection point 843. The cutter can also have a cutting diameter 880, where the cutting diameter is the maximum distance between first primary cutting edge 805 and second primary cutting edge 810, measured perpendicular to longitudinal axis 801. FIG. 8A illustrates radius 840 as a ball-nose radius at the distal end of cutter 800; in some embodiments, the radius can be half the cutting diameter. FIG. 8B illustrates cutter 800 with radius 840 as a corner radius at the distal end of the cutter, where the distal end of the cutter is substantially flat. Figure 8C shows a cutter 800 that is generally a ballnose radius, but where the distal-most portion of the cutter 800 is flat and has a radius that is a blend of a ballnose radius and a corner radius. Figure 8D shows a cutter 800 in which the cutting diameter 880 gradually decreases from the proximal end to the distal end, tapering, where the distal end can have a radius 840, which can be a ballnose radius, a cornernose radius (see Figure 8B), or a combination of a ballnose radius and a cornernose radius (see Figure 8C), as shown. The distal end of such a tapered cutter can have a diameter measured at the outer inflection point 843 that is 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or any percentage therein in 1% increments, of the cutting diameter 880 measured at the proximal end of the cutter.

[0136] Those skilled in the art will appreciate that in many embodiments, the radius at the distal end of the cutter can have any desired shape. In some embodiments, the radius is a ballnose radius. In some embodiments, the radius is a corner radius. In some embodiments, the radius is a combination of a ballnose radius and a corner radius. And, in some embodiments, the radius is equal to half the diameter of the cutter.

[0137] 9A-9C show perspective, proximal, and distal end views of primary and secondary blades and the primary and secondary facets forming the primary and secondary blades, which, according to some embodiments, improve tissue cutting by the cutter. Dashed lines highlight at least the distal-most portions of the primary and secondary cutting blades. In FIGS. 9A and 9B, cutter 900 features core 960, which forms the central portion of cutter 900 and includes cutter lumen 950. 9A and 9B show features that may be part of any cutter configuration, including a core 960 having at least a core diameter 961, a distal end, and a proximal end, where the distal end of the core 960 is configured with a first plurality of secondary facets 972 forming a first secondary cutting edge 910-1 subsequent to a first primary cutting edge 905-1 at a distal end of a first spiral groove 931; a second plurality of secondary facets 974 forming a second secondary cutting edge 910-2 subsequent to a secondary primary cutting edge 905-2 at a distal end of a second spiral groove 932. Additionally, the cutter may have a third plurality of secondary facets 976 at a distal end of a third spiral groove (not shown) forming a third secondary cutting edge 910-3 and subsequent to the third primary cutting edge 905-3. Those skilled in the art will appreciate that the formation of secondary cutting edges 910-1, 910-2, 910-3 along with the introduction of secondary facets 972, 974, 976 contribute to a cutter with the desirable "hybrid" capability of effectively cutting both soft and hard tissue, i.e., plaque, within a vessel.

[0138] Those skilled in the art will understand from the teachings provided herein that the "facets" are created on the "distal portion" of the cutter's core, as "core" is defined herein, the distal portion being less than the distal half of the cutter's length. In some embodiments, the distal portion is the distal 49% of the cutter's length. In some embodiments, the distal portion is the distal 40% of the cutter's length. In some embodiments, the distal portion is the distal 30% of the cutter's length. In some embodiments, the distal portion is the distal 20% of the cutter's length. In some embodiments, the distal portion is the distal 15% of the cutter's length. In some embodiments, the distal portion is the distal 10% of the cutter's length. In some embodiments, the distal portion is the distal 25%, 24%, 23%, 22%, 21%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or any percentage in 0.1% increments therein of the length of the cutter. In some embodiments, the distal portion is more than half the length of the cutter. In some embodiments, the distal portion is the distal 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, or any percentage in 0.1% increments therein of the length of the cutter.

[0139] Embodiments also include cutters having primary facets to improve tissue cutting by the primary cutting edges. As shown in FIG. 9A , in some embodiments, the distal end of the core further comprises a plurality of first primary facets 971 at the distal end of the first primary cutting edge 905-1. FIG. 9A also shows that in some embodiments, the distal end of the core further comprises a plurality of second primary facets 973 at the distal end of the second primary cutting edge 905-2. Additionally, as shown in FIG. 9A , the cutter can have a third plurality of primary facets 975 at the distal end of a third spiral groove (not shown) that forms the third primary cutting edge 905-3. In some embodiments, the plurality of first primary facets 971 may be configured to extend the reach of the first primary cutting edge 905-1; the plurality of second primary facets 973 may be configured to extend the distal reach of the second primary cutting edge 905-2; and, similarly, the plurality of third primary facets 975 may be configured to extend the distal reach of the third primary cutting edge 905-3.

[0140] Those skilled in the art will understand that each cutter taught herein is designed to include grooves. In some embodiments, a cutter can have two grooves. In some embodiments, a cutter can have three grooves. In some embodiments, a cutter can have four grooves. In some embodiments, a cutter can have five grooves. In some embodiments, a cutter can have six grooves. Each groove is helical and can have any desired angle of helix, so that combinations of grooves on a single cutter can have the same helix angle or a combination of helix angles.

[0141] As shown in FIG. 9C , the groove can have a groove depth 990, which can be defined by the distance between the surface of the core 960 at an inner point of the groove depth 990 and the surface of the first blade 905-1 at an outer point of the groove depth 990. In some embodiments, the helix angle and / or groove depth can vary from the proximal end to the distal end of the groove. In some embodiments, the groove depth can be in the range of 0.05 mm to 2.0 mm, 0.1 mm to 1.5 mm, 0.2 mm to 1.1 mm, 0.4 mm to 1.1 mm, 0.2 mm to 0.5 mm, 0.3 mm to 0.4 mm, 0.6 mm to 0.9 mm, or any range or amount therein in 0.1 mm increments. In some embodiments, the groove depth can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or any amount or range therein in 0.05 mm increments.

[0142] It should be understood that in some embodiments, the cutter has two, three, or four flutes. One skilled in the art will appreciate that the cutter can have any desired number of flutes, certainly at least two, and up to any reasonable number, while still retaining the ability to retain the primary and secondary cutting edge configuration. In some embodiments, the number of flutes matches the number of primary cutting edges, and the number of flutes can range from 2 to 8. In some embodiments, the number of flutes matches the number of primary cutting edges, and the number of flutes can be 2 to 4, 2 to 5, 2 to 6, 2 to 7, or 2 to 8 flutes. In some embodiments, the cutter can have three or four flutes. In some embodiments, the cutter has three flutes, three primary cutting edges, and three secondary cutting edges.

[0143] In some embodiments, each cutter flute can have the same or a different angle compared to the other flutes on the cutter. For example, one skilled in the art can select a cutter with such a variable flute configuration for a smoother cut. Thus, in some embodiments, the flute angle can be constant or variable. For example, one skilled in the art can select a "variable helix" for materials that are more resistant to cutting, or a variable flute angle between flutes, potentially improving cutting efficiency. A helix angle greater than 45° is considered a "high angle" and more efficiently removes material from the cut site, leaving a smoother cut surface while reducing tissue packing and tissue recutting. A helix angle less than 40° is considered a "low angle" and removes larger pieces of material in a given cutting time, resulting in a rougher cut surface, which may potentially result in tissue packing or recutting depending on the application. In some embodiments, the flutes can have a large helix angle. Also, in some embodiments, the flutes can have a low helix angle. In some embodiments, the flutes can have a helix angle ranging from 5° to 70°, or any angle within that range. In some embodiments, the grooves can have a helix angle ranging from 10° to 65°, or any angle within that range. In some embodiments, the grooves can have a helix angle ranging from 15° to 60°, or any angle within that range. In some embodiments, the grooves can have a helix angle ranging from 20° to 60°, or any angle within that range. In some embodiments, the grooves can have a helix angle ranging from 25° to 60°, or any angle within that range. Also, in some embodiments, the grooves can have a helix angle ranging from 30° to 60°, or any angle within that range. In some embodiments, the grooves can have a helix angle ranging from 35° to 40°, or any angle within that range. In some embodiments, the grooves can have a helix angle ranging from 37° to 45°, or any angle within that range. In some embodiments, the grooves can have a helix angle ranging from 30° to 45°, or any angle within that range.Additionally, in some embodiments, the grooves can have a helix angle ranging from 45° to 60°, or any angle within that range. Thus, the grooves can have a helix angle of approximately 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, or any angle therein in 0.1° increments. Those skilled in the art will further appreciate that a cutter can have a combination of grooves having any combination of helix angles.

[0144] 10A and 10B illustrate the mapping of primary and secondary facets and their relationship to the primary and secondary cutting edges, according to some embodiments. From the illustrations and teachings, those skilled in the art will recognize that the formation of primary and secondary facets at the distal end of the core contributes to the desired cutting efficiency for both hard and soft plaques. Those skilled in the art will also understand that any number of facets can be incorporated, and that facets, in some embodiments, are features of the distal end or portion of the cutter, which can be flat, concave, or convex. As shown in FIG. 10A , cutter 1000 includes secondary facets 1, 2, and 3 that are incorporated at the distal end or portion of the core to generate secondary cutting edges 1010-1, 1010-2, and 1010-3. In some embodiments, the distal end of the core may be configured with a first plurality of secondary facets 1, 2, 3 that form a first secondary cutting edge 1010-1 at the distal end of the first spiral groove 1031; in some embodiments, the distal end of the core may be configured with a second plurality of secondary facets 1', 2', 3' that form a second secondary cutting edge 1010-2 at the distal end of the second spiral groove 1032; and, in some embodiments, the distal end of the core may be configured with a third plurality of secondary facets 1'', 2'', 3'', that form a third secondary cutting edge 1010-3 at the distal end of the third spiral groove 1033.

[0145] 10A , the plurality of first secondary facets 1, 2 can be configured to extend the distal extent of the first secondary cutting blade 1010-1; in some embodiments, the plurality of second secondary cutting blades 1′, 2′ can be configured to extend the distal extent of the second secondary cutting blade 1010-2; and, similarly, in some embodiments, the plurality of third primary facets 1″, 2″ can be configured to extend the distal extent of the third secondary cutting blade 1010-3. The extended distal extents are indicated by the oval dashed outlines around the distal secondary blades 1010-1, 1010-2, 1010-3.

[0146] 10A , the distal end of the core 1060 further comprises a plurality of first primary facets 2′, 4″ at the distal end of the first primary cutting edge 1005-1; in some embodiments, the distal end of the core 1060 further comprises a plurality of second primary facets 2″, 4″ at the distal end of the second primary cutting edge 1005-2; and in some embodiments, the distal end of the core 1060 further comprises a plurality of third primary facets 2, 4″ at the distal end of the third primary cutting edge 1005-3.

[0147] As further shown in FIG. 10A , the plurality of first primary facets 2′, 4′ can be configured to extend the distal extent of the first primary cutting blade 1005-1; in some embodiments, the plurality of second primary facets 2″, 4″ can be configured to extend the distal extent of the second primary cutting blade 1005-2; and, similarly, in some embodiments, the plurality of third primary facets 2, 4″ can be configured to extend the distal extent of the third primary cutting blade 1005-3. The extended distal extents are indicated by the rectangular dashed outlines around the distal secondary blades 1010-1, 1010-2, 1010-3. FIG. 10B shows the distal end of an actual cutter and illustrates these primary and secondary facets on a prototype cutter that provided the desired results of cutting both soft and hard tissue.

[0148] In some embodiments, facets can be both primary facets, which help shape the primary cutting edges, and secondary facets, which help shape the secondary cutting edges 1010-1, 1010-2, and 1010-3. For example, in FIGS. 10A and 10B , facets 2, 2′, and 2″ function as both primary and secondary facets. Indeed, it can be seen that facets 1, 1′, and 1″ primarily function as secondary facets of the secondary cutting edges, but they also help shape small portions of the primary cutting edges 1005-1, 1005-2, and 1005-3, making them primary facets. At least in the illustrated embodiment, facets 3, 3′, and 3″ function only as secondary facets, and facets 4, 4′, and 4″ function only as primary facets.

[0149] 11A-11C show simplified diagrams of the distal end of two-blade, three-blade, and four-blade cutters, according to some embodiments, from the distal end toward the proximal end. In particular, the figures show the distal ends of the facets used to form at least the distal ends of the secondary cutting blades. FIG. 11A shows the distal end of a two-blade cutter having two primary cutting blades 1105 and two secondary cutting blades 1110. In this embodiment, the distal end of the cutter is a four-sided polygon, which may be square or rectangular, and can have any desired cross-sectional area, with the minimum cross-sectional area being greater than the cross-sectional area of ​​the cutter lumen and less than the cross-sectional area defined by the cutter's diameter. The sides of the four-sided polygon are the distal ends of the facets that form the secondary cutting blades. In FIG. 11A, facets 1, 2, 1', and 2' define at least the distal portion of the secondary cutting blade 1110. FIG. 11B shows the distal end of a three-blade cutter having three primary cutting edges 1105 and three secondary cutting edges 1110. In this embodiment, the distal end of the cutter is a six-sided polygon, which can be hexagonal, as shown in FIG. 10B, or more triangular; it can have any desired cross-sectional area, with the smallest cross-sectional area being greater than the cross-sectional area of ​​the cutter lumen and less than the cross-sectional area defined by the cutter's diameter. The sides of the six-sided polygon are the distal ends of the facets that form the secondary cutting edges. In FIG. 11B, facets 1, 2, 1', 2', 1", and 2" define at least a distal portion of the secondary blade 1110. FIG. 11B also shows a side view of the distal end of the cutter, illustrating three optional shapes for the distal end: flat, convex, and concave. Those skilled in the art will understand that these are exemplary shapes and that any desired shape can be used to facilitate tissue cutting and removal by the primary blades, secondary blades, and flutes. 11C shows the distal end of a four-blade cutter having four primary cutting edges 1105 and four secondary cutting edges 1110. In this embodiment, the distal end of the cutter is octagonal, which may be octagonal or more rectangular, but can have any cross-sectional area, the smallest being greater than the cross-sectional area of ​​the cutter lumen and less than the cross-sectional area defined by the diameter of the cutter. The sides of the octagon are the distal ends of the facets that form the secondary cutting edges.In FIG. 11C, facets 1, 2, 1', 2', 1'', 2'', 1''', and 2''' define at least the distal portion of the secondary cutting edge 1110. FIG. 11C also shows a side view of the distal end of the cutter and shows three options for constructing a distal end having tissue disrupting protrusions, namely sharp, blunt, and rounded. One of ordinary skill in the art will understand that these are exemplary protrusions and that any desired protrusion having the function of disrupting tissue can be used to facilitate the cutting and removal of tissue by the primary blade, secondary blade, and longitudinal groove channels.

[0150] It should be understood that any of the features shown in FIGS. 11A - 11C can be used with any cutter manufactured using the teachings provided herein, regardless of the combination and number of primary cutting edges, secondary cutting edges, grooves, the shape and cross-sectional area of the distal end of the cutter, etc. However, this teaching is not meant to suggest that the illustrated exemplary facets are always sufficient to obtain the desired shape in a cutter. It should also be understood that the facets shown for shaping at least the distal end of the secondary cutting edge may be useful for shaping at least the distal end of the primary cutting edge, but additional facets may be and often are needed to shape at least the distal end of the primary cutting edge to the desired shape.

[0151] Those skilled in the art will appreciate that a cutter can be configured with any number of primary and secondary cutting blades, and the number of primary and secondary cutting blades can be the same or different. In some embodiments, a cutter can have two primary cutting blades and zero secondary cutting blades. In some embodiments, a cutter can have two primary cutting blades and one secondary cutting blade. In some embodiments, a cutter can have two primary cutting blades and two secondary cutting blades. In some embodiments, a cutter can have two primary cutting blades and three secondary cutting blades. In some embodiments, a cutter can have three primary cutting blades and zero secondary cutting blades. In some embodiments, a cutter can have three primary cutting blades and one secondary cutting blade. In some embodiments, a cutter can have three primary cutting blades and two secondary cutting blades. In some embodiments, a cutter can have three primary cutting blades and three secondary cutting blades. In some embodiments, a cutter can have three primary cutting blades and four secondary cutting blades. In some embodiments, a cutter can have four primary cutting blades and zero secondary cutting blades. In some embodiments, a cutter can have four primary cutting blades and one secondary cutting blade. In some embodiments, the cutter can have four primary cutting edges and two secondary cutting edges. In some embodiments, the cutter can have four primary cutting edges and three secondary cutting edges. In some embodiments, the cutter can have four primary cutting edges and four secondary cutting edges. In some embodiments, the cutter can have four primary cutting edges and five secondary cutting edges.

[0152] In some embodiments, the cutter can have a third primary cutting edge that extends helically along a radius at the distal end of the cutter from the distal end to the proximal end; the third spiral groove has a helix angle and forms an open spiral channel at the distal and proximal ends. In some embodiments, the core can further be configured with a third plurality of secondary facets that form the third secondary cutting edge at the distal end of the third spiral groove. Similarly, the core can further be configured with a third plurality of primary facets at the distal end of the third primary cutting edge, the third plurality of primary facets configured to extend the distal extent of the third primary cutting edge.

[0153] In some embodiments, the cutter can have a third primary cutting edge extending helically along a radius at the distal end of the cutter from the distal end to the proximal end; a fourth primary cutting edge extending helically along a radius from the distal end to the proximal end; the third spiral groove having a helix angle and forming an open spiral channel at the distal and proximal ends; and the fourth spiral groove having a helix angle and forming an open spiral channel at the distal and proximal ends. In some embodiments, the core can further comprise a third plurality of secondary facets forming a third secondary cutting edge at the distal end of the third spiral groove; and the fourth plurality of secondary facets forming a fourth secondary cutting edge at the distal end of the third spiral groove. Similarly, the core can be configured to further include a third plurality of primary facets at a distal end of the third primary cutting edge, the third plurality of primary facets configured to extend a distal extent of the third primary cutting edge; and a fourth plurality of primary facets at a distal end of the fourth primary cutting edge, the fourth plurality of primary facets configured to extend a distal extent of the fourth primary cutting edge.

[0154] Those skilled in the art will appreciate that the primary and / or secondary blades may be formed with a "clearance angle" to reduce drag of the cutting edge against tissue and increase the cutting efficiency of the cutter. However, a clearance angle is not a "facet" as described in the technology provided herein. While in some embodiments, the facets may also provide a clearance angle, the primary purpose of the facets is to remove core material to define the presence of a secondary cutting edge in the distal portion of the cutter, and in some embodiments, to extend the distal extent of the primary blade at the distal end of the cutter.

[0155] Those skilled in the art will understand that any of the atherectomy devices taught herein have several technical contributions of their own besides the cutter configuration, and that any of the atherectomy devices can include any of the cutters taught herein to further enhance the performance of the atherectomy device. In some embodiments, the atherectomy device includes: a cutter having a clear diameter as taught herein; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the longitudinal direction; a flexible sheath having an outer diameter and a sheath lumen; and a drive assembly, the drive assembly including: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath, the drive assembly also including a positive displacement pump that initiates pumping at the distal end of the drive shaft adjacent to a helical groove in the proximal end of the cutter. In these embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible sheath; the flexible drive shaft may be longer than the flexible sheath so that the drive assembly can be reversibly extended and retracted from the lumen of the flexible sheath at the distal end of the flexible sheath; and the guidewire lumen may include a cutter lumen and a drive shaft lumen.

[0156] In some embodiments, the atherectomy device comprises: a cutter as taught herein, said cutter having a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; a drive assembly having a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter; wherein the flexible drive shaft rotatably translates with the lumen of the flexible sheath, and the drive assembly also has a screw pump attached to the outer surface of the drive shaft and adjacent to a helical groove in the proximal end of the cutter, the screw pump including a drive screw portion; wherein the drive screw portion extends beyond the flexible sheath and is exposed for contact with the vascular lumen during use of the atherectomy device within the vascular lumen; and wherein when the cutter is rotated in a right direction, the threads are right-handed; or when the cutter is rotated in a left-handed direction, the threads are left-handed. In these embodiments, the clear diameter of the cutter may be larger than the outer diameter of the flexible drive shaft; and the guidewire lumen may include the cutter lumen and the drive shaft lumen.

[0157] In some embodiments, the atherectomy device includes: a cutter as taught herein, said cutter having a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; a drive assembly having a flexible drive shaft comprising an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter; wherein the flexible drive shaft rotatably translates with the lumen of the flexible sheath, and wherein the drive assembly also has a positive displacement pump at the distal end of the drive shaft that initiates pumping adjacent to the helical groove in the proximal end of the cutter. And, the atherectomy device can also include a reversibly expandable lateral pusher member at the distal end of the flexible sheath, the lateral pusher member having a proximal end, a distal end, a collapsed state, and an expanded state, the proximal end in operable connection with the flexible sheath, and the distal end in operable connection with the cutter. In some embodiments, the clear diameter of the cutter is larger than the outer diameter of the flexible drive shaft; and the guidewire lumen can include a cutter lumen and a drive shaft lumen. Furthermore, the operable connection with the flexible sheath and the operable connection with the cutter may each be configured to receive an axial force (i) applied from the cutter along the axis of the flexible drive shaft to the flexible sheath, and (ii) moved through the lateral push member during contraction and expansion of the lateral push member by reversibly extending and retracting the flexible drive shaft from the flexible sheath; and the operable connection with the cutter may be configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral push member during operation of the atherectomy device.

[0158] 12 illustrates a method of performing an atherectomy, according to some embodiments. Those skilled in the art will also understand that any method of performing an atherectomy can include using any of the atherectomy devices taught herein with any of the cutters taught herein. Regardless of the atherectomy device used, the method 1200 can include creating an entry point in the lumen of a subject's blood vessel 1205; inserting the atherectomy device into the lumen of the blood vessel 1210; severing plaque from the lumen of the blood vessel using the cutter of the atherectomy device 1215; ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump 1255; and removing the atherectomy device from the lumen of the subject's blood vessel 1260. The method also includes the step of advancing 1240 a cutter head into contact with tissue for removal using the improved cutter control features of the atherectomy devices provided herein, including telescoping 1220 a flexible drive shaft to contact the target tissue for removal, driving 1244 the cutter with an exposed drive screw to contact the target tissue for removal, pushing 1230 the cutter with a lateral pushing member to contact the target tissue for removal, or any combination thereof. Such combinations may include, for example, telescoping / drive 1242, drive / lateral pushing 1245, telescoping / lateral pushing 1243, and telescoping / drive / lateral pushing 1246. Thus, in addition to the optional step 1201 of selecting an atherectomy device having a cutter that is faceted for the secondary cutting edge, which may also be faceted to extend the primary cutting edge further distally, the selection is limited to the various cutters taught herein, and FIG. 12 illustrates at least seven different methods of performing atherectomy using the atherectomy devices taught herein.

Claims

1. 1. An atherectomy device comprising: a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; a cutter having a proximal end, a distal end, and a body with a plurality of spiral grooves, a point at the distal end with a plurality of cutting lips, a cutter lumen, and a clear diameter; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; and a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the spiral grooves in the proximal end of the cutter; the drive assembly having Including, wherein the clear diameter of the cutter is larger than the outer diameter of the flexible drive shaft; the flexible drive shaft is longer than the flexible sheath and allows the drive assembly to be reversibly extended and retracted from the lumen of the flexible sheath at the distal end of the flexible sheath; and the guidewire lumen includes a cutter lumen and a drive shaft lumen. The atherectomy device.

2. 10. The atherectomy device of claim 1, wherein the clear diameter of the cutter is greater than the outer diameter of the flexible sheath.

3. 10. The atherectomy device of claim 1, wherein the positive displacement pump is a screw pump attached to the exterior surface of the drive shaft, a distal end of the screw pump adjacent the helical groove in the proximal end of the cutter.

4. a screw pump extending beyond the flexible sheath and exposed for contact with the vessel lumen during use of the atherectomy device within the vessel lumen; and If the cutter rotates to the right, it is a right-hand thread, or If you want to rotate the cutter to the left, it must be a left-handed screw.

4. The atherectomy device of claim 3.

5. 10. The atherectomy device of claim 1, further comprising a reversibly expandable lateral pushing member at a distal end of the flexible sheath.

6. further comprising a reversibly expandable lateral pushing member at a distal end of the flexible sheath, the lateral pushing member having a proximal end, a distal end, a collapsed state, and an expanded state, the proximal end being in operable connection with the flexible sheath and the distal end being in operable connection with the cutter; where: The operative connection with the flexible sheath and the operative connection with the cutter are each configured to receive an axial force (i) applied along the axis of the flexible drive shaft from the cutter to the flexible sheath, and (ii) travelling through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and contraction of the flexible drive shaft from the flexible sheath; and the operable connection with the cutter is configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device; 10. The atherectomy device of claim 1.

7. 1. An atherectomy device comprising: a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; a cutter having a proximal end, a distal end, and a body with a plurality of spiral grooves, a point at the distal end with a plurality of cutting lips, a cutter lumen, and a clear diameter; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; and a screw pump attached to an outer surface of the drive shaft adjacent the helical groove in the proximal end of the cutter and including a drive screw portion extending beyond the flexible sheath and exposed for contact with the vessel lumen during use of the atherectomy device within the vessel lumen, the drive screw portion being right-handed when the cutter is rotated in a right direction or left-handed when the cutter is rotated in a left direction; the drive assembly having Includes wherein the clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; and The guidewire lumen encompasses the cutter lumen and the drive shaft lumen. The atherectomy device.

8. 8. The atherectomy device of claim 7, wherein the clear diameter of the cutter is greater than the outer diameter of the flexible sheath.

9. 8. The atherectomy device of claim 7, wherein the drive screw portion is a distal portion of a screw pump.

10. 8. The atherectomy device of claim 7, wherein the flexible drive shaft is longer than the flexible sheath to enable reversible extension and retraction of the drive assembly from the lumen of the flexible sheath at the distal end of the flexible sheath.

11. 8. The atherectomy device of claim 7, further comprising a reversibly expandable lateral push member at the distal end of the flexible sheath.

12. a lateral pushing member having a proximal end, a distal end, a collapsed state and a deployed state, the proximal end having an operable connection with the flexible sheath, and the distal end having an operable connection with the cutter; where: The operative connection with the flexible sheath and the operative connection with the cutter are each configured to receive an axial force (i) applied along the axis of the flexible drive shaft from the cutter to the flexible sheath, and (ii) travelling through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and contraction of the flexible drive shaft from the flexible sheath; and the operable connection with the cutter is configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device; 12. The atherectomy device of claim 11.

13. 1. An atherectomy device comprising: a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; a cutter having a proximal end, a distal end, and a body with a plurality of spiral grooves, a point at the distal end with a plurality of cutting lips, a cutter lumen, and a clear diameter; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the spiral grooves in the proximal end of the cutter; the drive assembly having a reversibly expandable lateral pushing member at the distal end of the flexible sheath; Including, wherein the clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; and the guidewire lumen comprises a cutter lumen and a drive shaft lumen. The atherectomy device.

14. 14. The atherectomy device of claim 13, wherein the clear diameter of the cutter is greater than the outer diameter of the flexible sheath.

15. a lateral pushing member having a proximal end, a distal end, a collapsed state and a deployed state, the proximal end having an operable connection with the flexible sheath, and the distal end having an operable connection with the cutter; where: The operative connection with the flexible sheath and the operative connection with the cutter are each configured to receive an axial force (i) applied along the axis of the flexible drive shaft from the cutter to the flexible sheath, and (ii) travelling through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and contraction of the flexible drive shaft from the flexible sheath; and the operable connection with the cutter is configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device; 14. The atherectomy device of claim 13.

16. 14. The atherectomy device of claim 13, wherein the flexible drive shaft is longer than the flexible sheath to enable reversible extension and retraction of the drive assembly from the lumen of the flexible sheath at the distal end of the flexible sheath.

17. further including a drive screw attached to an outer surface of the distal end of the drive shaft and adjacent to the screw pump at the distal end of the screw pump; Here, the drive screw is extending beyond the flexible sheath and exposed for contact with the vessel lumen during use of the atherectomy device within the vessel lumen; If the cutter is rotated to the right, it is a right-hand thread; and If the cutter rotates to the right, it is a right-hand thread; or If you rotate the cutter to the left, it is either a left-handed thread, 14. The atherectomy device of claim 13.

18. A system comprising the atherectomy device of claim 1 and a guidewire.

19. A system comprising the atherectomy device of claim 7 and a guidewire.

20. 14. A system comprising the atherectomy device of claim 13 and a guidewire.

21. 10. A method of performing atherectomy on a subject using the atherectomy device of claim 1, the method comprising: creating an entry point in the target vessel lumen; inserting an atherectomy device into the lumen of a blood vessel; extending and retracting a flexible drive shaft; severing the plaque from the lumen of the blood vessel using a cutter from the atherectomy device; Ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the subject's blood vessel; The method comprising:

22. 10. A method of performing atherectomy on a subject using the atherectomy device of claim 7, the method comprising: creating an entry point in the target vessel lumen; inserting an atherectomy device into the lumen of a blood vessel; driving the atherectomy device through the lumen of the vessel with the exposed drive screw; severing the plaque from the lumen of the blood vessel using a cutter from the atherectomy device; Ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the subject's blood vessel; The method comprising:

23. 14. A method of performing atherectomy on a subject using the atherectomy device of claim 13, the method comprising: creating an entry point in the target vessel lumen; inserting an atherectomy device into the lumen of a blood vessel; pushing a distal portion of the atherectomy device laterally within the lumen of the blood vessel, the pushing including expanding a lateral pushing member; severing the plaque from the lumen of the blood vessel using a cutter from the atherectomy device; Ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the subject's blood vessel; The method comprising:

24. 10. The atherectomy device of claim 1, further comprising a compressible sleeve for increasing the torsional stiffness of the lateral pusher member.

25. 1. A hybrid atherectomy cutter for cutting a combination of soft and hard plaques, the cutter comprising: a proximal end, a distal end, and a longitudinal axis; a cut length, defined by the distance from the proximal end to the distal end along the longitudinal axis; a radius at the distal end, having an inner inflection point and an outer inflection point; a first primary cutting edge and a second primary cutting edge, the first primary cutting edge and the second primary cutting edge extending spirally along a radius from the distal end to the proximal end; a first helical groove and a second helical groove, each of the first helical groove and the second helical groove having a helix angle and forming an open helical channel at a distal end and a proximal end; a cutting diameter, which is the maximum distance between the first and second primary cutting edges measured perpendicular to the longitudinal axis; a core having a core diameter, a distal end, and a proximal end, the distal end of the core configured with a first plurality of secondary facets forming a first secondary cutting edge at a distal end of a first spiral groove, and a second plurality of secondary facets forming a second secondary cutting edge at a distal end of a second spiral groove; Including, Here, the cutter is having a lumen configured to allow a guidewire to pass therethrough; and Effectively cuts both soft and hard plaques in blood vessels. The cutter.

26. 26. The cutter of claim 25, wherein the radius is a ball nose radius.

27. 26. The cutter of claim 25, wherein the radius is a corner radius.

28. 26. A cutter according to claim 25, wherein the radius is equal to half the diameter of the cutter.

29. 26. The cutter of claim 25, wherein the helix angle is in the range of 30 degrees to 45 degrees.

30. the distal end of the core further comprises: a plurality of first primary facets at a distal end of the first primary cutting edge; and a plurality of second primary facets at a distal end of the second primary cutting edge; where: the plurality of first primary facets are configured to extend the reach of the first primary cutting edge; and the plurality of second primary facets are configured to extend a distal extent of the second primary cutting edge; 26. A cutter according to claim 25.

31. a third primary cutting edge extending spirally along a radius from the distal end to the proximal end; and a third helical groove having a helical angle and forming an open helical channel at the distal and proximal ends; 26. The cutter of claim 25, further comprising:

32. a third primary cutting edge extending spirally along a radius from the distal end to the proximal end; and a third helical groove having a helix angle and forming an open helical channel at the distal end and the proximal end; wherein the core is further configured with a third plurality of secondary facets forming a third secondary cutting edge at a distal end of the third spiral groove; 26. A cutter according to claim 25.

33. a third primary cutting edge extending spirally along a radius from the distal end to the proximal end; and a third helical groove having a helix angle and forming an open helical channel at the distal end and the proximal end; Here, the core further a third plurality of secondary facets forming a third secondary cutting edge at a distal end of the third spiral groove; and a third plurality of primary facets at a distal end of the third primary cutting edge, the third plurality of primary facets configured to extend a distal extent of the third primary cutting edge; 26. The cutter of claim 25, wherein

34. a third primary cutting edge extending spirally along a radius from the distal end to the proximal end; a fourth primary cutting edge extending spirally along a radius from the distal end to the proximal end; a third helical groove having a helical angle and forming an open helical channel at the distal and proximal ends; and a fourth helical groove having a helix angle and forming an open helical channel at the distal and proximal ends; 26. The cutter of claim 25, further comprising:

35. a third primary cutting edge extending spirally along a radius from the distal end to the proximal end; a fourth primary cutting edge extending spirally along a radius from the distal end to the proximal end; a third helical groove having a helical angle and forming an open helical channel at the distal and proximal ends; and a fourth helical groove having a helix angle and forming an open helical channel at the distal and proximal ends; further comprising Here, the core further a third plurality of secondary facets forming a third secondary cutting edge at a distal end of the third spiral groove; and a fourth plurality of secondary facets forming a fourth secondary cutting edge at a distal end of the third spiral flute; 26. The cutter of claim 25, wherein

36. a third primary cutting edge extending spirally along a radius from the distal end to the proximal end; a fourth primary cutting edge extending spirally along a radius from the distal end to the proximal end; a third helical groove having a helical angle and forming an open helical channel at the distal and proximal ends; and a fourth helical groove having a helix angle and forming an open helical channel at the distal and proximal ends; further comprising Here, the core further a third plurality of secondary facets forming a third secondary cutting edge at a distal end of the third spiral groove; and a third plurality of primary facets at a distal end of the third primary cutting edge, the third plurality of primary facets configured to extend a distal extent of the third primary cutting edge; a fourth plurality of secondary facets forming a fourth secondary cutting edge at a distal end of the third spiral flute; a fourth plurality of primary facets at a distal end of the fourth primary cutting edge, the fourth plurality of primary facets configured to extend a distal extent of the fourth primary cutting edge; 26. The cutter of claim 25, wherein

37. 1. An atherectomy device comprising:

26. The cutter of claim 25, wherein the cutter has a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the spiral grooves in the proximal end of the cutter; the drive assembly having Including, where: The clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; the flexible drive shaft is longer than the flexible sheath and is capable of reversibly extending and retracting the drive assembly from the lumen of the flexible sheath at the distal end of the flexible sheath; and The guidewire lumen encompasses the cutter lumen and the drive shaft lumen. The atherectomy device.

38. 1. An atherectomy device comprising:

26. The cutter of claim 25, wherein the cutter has a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; a screw pump attached to an outer surface of the drive shaft adjacent the helical groove in the proximal end of the cutter and including a drive screw portion extending beyond the flexible sheath and exposed for contact with the vessel lumen during use of the atherectomy device within the vessel lumen, the drive screw portion being right-handed when the cutter is rotated in a right direction or left-handed when the cutter is rotated in a left direction; the drive assembly having Includes where: The clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; and The guidewire lumen includes a cutter lumen and a drive shaft lumen. The atherectomy device.

39. 1. An atherectomy device comprising:

26. The cutter of claim 25, wherein the cutter has a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the spiral grooves in the proximal end of the cutter; the drive assembly having: a reversibly expandable lateral pushing member at the distal end of a flexible sheath, the lateral pushing member having a proximal end, a distal end, a collapsed state, and an expanded state, the proximal end being in operable connection with the flexible sheath and the distal end being in operable connection with the cutter; Including, where: The clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; The guidewire lumen includes a cutter lumen and a drive shaft lumen; The operative connection with the flexible sheath and the operative connection with the cutter are each configured to receive an axial force (i) applied along the axis of the flexible drive shaft from the cutter to the flexible sheath, and (ii) travelling through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and contraction of the flexible drive shaft from the flexible sheath; and the operable connection with the cutter is configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device; The atherectomy device.

40. 1. An atherectomy device comprising:

34. The cutter of claim 33, wherein the cutter has a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the spiral grooves in the proximal end of the cutter; the drive assembly having Including, where: The clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; the flexible drive shaft is longer than the flexible sheath and is capable of reversibly extending and retracting the drive assembly from the lumen of the flexible sheath at the distal end of the flexible sheath; and The guidewire lumen encompasses the cutter lumen and the drive shaft lumen. The atherectomy device.

41. 1. An atherectomy device comprising:

34. The cutter of claim 33, wherein the cutter has a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; and A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; a screw pump attached to an outer surface of the drive shaft adjacent the helical groove in the proximal end of the cutter and including a drive screw portion extending beyond the flexible sheath and exposed for contact with the vessel lumen during use of the atherectomy device within the vessel lumen, the drive screw portion being right-handed when the cutter is rotated in a right direction or left-handed when the cutter is rotated in a left direction; the drive assembly having Includes where: The clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; and The guidewire lumen includes a cutter lumen and a drive shaft lumen. The atherectomy device.

42. 1. An atherectomy device comprising:

34. The cutter of claim 33, wherein the cutter has a clear diameter; a distal end, a proximal end, a longitudinal axis, and a guidewire lumen passing through the device in the direction of the longitudinal axis; a flexible sheath having an outer diameter and a sheath lumen; A drive assembly comprising: a flexible drive shaft including an axis, a proximal end, a distal end, an outer surface, and a drive shaft lumen, the distal end of the flexible drive shaft having a fixed connection with the cutter, the flexible drive shaft rotatably translating relative to the lumen of the flexible sheath; a positive displacement pump that begins pumping at the distal end of the drive shaft adjacent the spiral groove in the proximal end of the cutter; and a reversibly expandable lateral pushing member at the distal end of a flexible sheath, the lateral pushing member having a proximal end, a distal end, a collapsed state, and an expanded state, the proximal end being in operable connection with the flexible sheath and the distal end being in operable connection with the cutter; the drive assembly having Including, where: The clear diameter of the cutter is greater than the outer diameter of the flexible drive shaft; The guidewire lumen includes a cutter lumen and a drive shaft lumen; The operative connection with the flexible sheath and the operative connection with the cutter are each configured to receive an axial force (i) applied along the axis of the flexible drive shaft from the cutter to the flexible sheath, and (ii) travelling through the lateral pusher member during contraction and expansion of the lateral pusher member due to reversible extension and contraction of the flexible drive shaft from the flexible sheath; and the operable connection with the cutter is configured as a rotatably translatable connection to facilitate rotation of the cutter and flexible drive shaft without rotating the lateral pusher member during operation of the atherectomy device; The atherectomy device.

43. 40. A method of performing atherectomy on a subject using the atherectomy device of claim 39, the method comprising: creating an entry point in the target vessel lumen; inserting an atherectomy device into the lumen of a blood vessel; extending and retracting a flexible drive shaft; severing the plaque from the lumen of the blood vessel using a cutter from the atherectomy device; Ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the subject's blood vessel; The method comprising:

44. 43. A method of performing atherectomy on a subject using the atherectomy device of claim 42, the method comprising: creating an entry point in the target vessel lumen; inserting an atherectomy device into the lumen of a blood vessel; driving the atherectomy device through the lumen of the vessel with the exposed drive screw; severing the plaque from the lumen of the blood vessel using a cutter from the atherectomy device; Ejecting the severed plaque from the lumen of the blood vessel using a positive displacement pump; and removing the atherectomy device from the lumen of the subject's blood vessel; The method comprising:

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