阅读说明：本技术 具有耦合内衬的组织移除导管 (Tissue-removing catheter with coupled liner ) 是由 R·M·赫勒伯特 T·P·海登 A·詹莫斯 C·麦克马伦 T·K·凯利 M·J·多尼甘 于 2021-08-12 设计创作，主要内容包括：一种用于移除体腔中的组织的组织移除导管。所述组织移除导管可包括：细长主体,其具有轴线以及沿着所述轴线彼此间隔开的近端部分和远端部分,所述细长主体大小和形状设定成被接收于所述体腔中；柄部,其安装到所述细长主体的所述近端部分,所述柄部包括围封可操作以引起所述细长主体旋转的部件的壳体；组织移除元件,其安装在所述细长主体的所述远端部分上,所述组织移除元件被配置成在所述组织移除元件通过所述细长主体在所述体腔内旋转时移除所述组织；内衬,其被接收于所述细长主体内并限定导丝腔；以及推进器,其安装在所述柄部上并且能相对于所述壳体移动,所述内衬在所述内衬的近端部分处耦合到所述推进器,使得所述推进器的移动引起所述内衬的相应移动,从而对所述组织移除元件施加推力以推进所述组织移除元件并对所述组织移除元件施加拉力以使所述组织移除元件缩回,以使所述组织移除元件相对于所述柄部移动。(A tissue removal catheter for removing tissue in a body lumen. The tissue-removing catheter may comprise: an elongated body having an axis and proximal and distal portions spaced apart from each other along the axis, the elongated body sized and shaped to be received in the body lumen; a handle mounted to the proximal end portion of the elongated body, the handle comprising a housing enclosing components operable to cause rotation of the elongated body; a tissue removal element mounted on the distal end portion of the elongate body, the tissue removal element configured to remove the tissue as the tissue removal element is rotated within the body lumen by the elongate body; a liner received within the elongate body and defining a guidewire lumen; and an advancer mounted on the handle and movable relative to the housing, the liner coupled to the advancer at a proximal end portion of the liner such that movement of the advancer causes corresponding movement of the liner to apply a pushing force to the tissue-removing element to advance the tissue-removing element and a pulling force to the tissue-removing element to retract the tissue-removing element to move the tissue-removing element relative to the handle.)

1. A tissue-removing catheter for removing tissue in a body lumen, the tissue-removing catheter comprising:

an elongate body having an axis and proximal and distal portions spaced apart from each other along the axis, wherein the elongate body is sized and shaped to be received in the body lumen;

a handle mounted to the proximal end portion of the elongated body, the handle comprising a housing enclosing a component operable to cause rotation of the elongated body;

a tissue removal element mounted on the distal end portion of the elongate body, the tissue removal element configured to remove the tissue as the tissue removal element is rotated within the body lumen by the elongate body;

a liner received within the elongate body and defining a guidewire lumen; and

a pusher mounted on the handle and movable relative to the housing, the liner coupled to the pusher at a proximal end portion of the liner such that movement of the pusher causes corresponding movement of the liner to apply a pushing force on the tissue-removing element to advance the tissue-removing element and a pulling force on the tissue-removing element to retract the tissue-removing element to move the tissue-removing element relative to the handle.

2. The tissue-removing catheter set forth in claim 1, further comprising a coupling assembly in the handle that couples the liner to the pusher.

3. The tissue-removing catheter set forth in claim 2, wherein the liner is coupled to the tissue-removing element at a distal portion of the liner.

4. The tissue-removing catheter set forth in claim 3, further comprising a liner assembly including the liner and a wedge fixedly attached to a proximal end of the liner, wherein the coupling assembly is directly attached to the wedge.

5. The tissue-removing catheter set forth in claim 4, wherein the coupling assembly comprises a coupling sleeve fixedly attached to the wedge.

6. The tissue-removing catheter set forth in claim 5, wherein the coupling assembly includes a guide tube attached to a distal portion of the coupling sleeve.

7. The tissue-removing catheter set forth in claim 6, further comprising a motor in the handle and operatively engaging the elongate body for driving rotation of the elongate body and a tissue-removing element mounted thereon.

8. The tissue-removing catheter set forth in claim 7, further comprising a gearbox housing at least partially enclosing a gear assembly operatively connected to the motor.

9. The tissue-removing catheter set forth in claim 8, wherein a proximal end of the guide tube is attached to the coupling sleeve and a distal end of the guide tube is attached to the gearbox housing.

10. The tissue-removing catheter set forth in claim 9, wherein the guide tube is fixedly attached to the gearbox housing.

11. The tissue-removing catheter set forth in claim 9, further comprising a bracket mounting the motor in the handle and connecting the pusher to the gearbox housing.

12. The tissue-removing catheter set forth in claim 11, wherein the coupling assembly includes the cradle and a gearbox housing.

13. The tissue-removing catheter set forth in claim 5, further comprising a locker tube in the handle, wherein the coupling sleeve is received in the locker tube in non-rotational sliding engagement.

14. The tissue-removing catheter set forth in claim 13, further comprising a wire through port mounted on a proximal end of the locker tube.

15. The tissue-removing catheter set forth in claim 5, wherein the coupling sleeve includes at least one magnet configured to attach to the wedge.

16. The tissue-removing catheter set forth in claim 5, wherein the coupling sleeve is attached to the wedge by a snap-fit connection.

17. The tissue-removing catheter set forth in claim 16, wherein one of the coupling sleeve and wedge includes a deflectable arm configured for snap-fit engagement with the other of the coupling sleeve and wedge.

18. The tissue-removing catheter set forth in claim 2, wherein the coupling assembly fixedly couples the liner to the pusher such that movement of the pusher causes the same corresponding movement of the liner.

19. The tissue-removing catheter set forth in claim 18, wherein the liner is fixedly coupled to the elongate body at the distal end portion of the elongate body.

20. The tissue-removing catheter set forth in claim 1, wherein the liner is not directly attached with a tissue-removing element.

Technical Field

The present disclosure relates generally to a tissue-removing catheter and, more particularly, to a coupling liner for a tissue-removing catheter.

Background

Tissue removal catheters are used to remove unwanted tissue in a body cavity. For example, atherectomy catheters are used to remove material from blood vessels to open the blood vessels and improve the flow of blood in the blood vessels. This procedure can be used to present (prepare) lesions in the coronary arteries of a patient to facilitate Percutaneous Transluminal Coronary Angioplasty (PTCA) or stent delivery in patients with heavily calcified coronary lesions. Atherectomy catheters typically employ rotating elements that are used to abrade or otherwise destroy unwanted tissue.

Drawings

Fig. 1 is a schematic illustration of a catheter of the present disclosure;

FIG. 2 is an enlarged front view of the distal portion of the catheter;

FIG. 3 is a cross-section taken through line 3-3 in FIG. 2;

FIG. 4 is a top perspective view of the handle of the catheter;

FIG. 5 is a top perspective view of the handle with the top housing segment removed;

FIG. 6 is a perspective view of the gears of the gear assembly in the handle;

FIG. 7A is an exploded view of the internal components in the handle;

FIG. 7B is a perspective view of the coupling sleeve in the handle;

FIG. 8 is a fragmentary perspective view of a liner assembly of the catheter;

FIG. 9 is a cross-section of a liner wedge (key) of the liner assembly;

FIG. 10 is a fragmentary elevation view of an insulation liner of a catheter, with portions broken away to show internal detail;

FIG. 11 is an enlarged fragmentary longitudinal section of the distal portion of the catheter of FIG. 2;

FIG. 12 is an enlarged longitudinal cross-section of a tissue-removing element of the catheter;

FIG. 13 is a perspective view of a liner of a catheter;

FIG. 14 is a perspective view of a first bearing of the catheter;

FIG. 15 is a perspective view of a second bearing of the catheter;

FIG. 16A is an illustration of a coupling assembly of another embodiment;

FIG. 16B is an illustration of a coupling assembly of another embodiment;

FIG. 17 is a schematic illustration of a coupling assembly of another embodiment;

FIG. 18 is an illustration of a coupling assembly of another embodiment; and

fig. 19A-C are illustrations of coupling assemblies of another embodiment.

Corresponding reference characters indicate corresponding parts throughout the drawings.

Detailed Description

Referring to the drawings, and in particular to FIG. 1, a rotary tissue removal catheter for removing tissue in a body lumen is indicated generally by the reference numeral 10. The illustrated catheter 10 is a rotational atherectomy device adapted to remove (e.g., abrade, cut, resect, ablate, etc.) occlusive tissue (e.g., embolic tissue, plaque tissue, atheroma, thrombolytic tissue, stenotic tissue, hyperplastic tissue, neoplastic tissue, etc.) from a vessel wall (e.g., coronary artery wall, etc.). The catheter 10 may be used to facilitate Percutaneous Transluminal Coronary Angioplasty (PTCA) or subsequent stent delivery. Features of the disclosed embodiments may also be suitable for treating Chronic Total Occlusion (CTO) of blood vessels, as well as strictures of other body lumens and other proliferative and neoplastic conditions in other body lumens such as ureters, bile ducts, respiratory tracts, pancreatic ducts, lymphatic ducts, and the like. Neoplastic cell growth often occurs due to tumors surrounding and invading body cavities. Thus, removal of such materials may be beneficial for maintaining patency of the body cavity.

The catheter 10 is sized to be received in a blood vessel of a subject. Thus, depending on the body lumen, the catheter 10 may have a maximum size of 3, 4, 5, 6, 7, 8, 9, 10, or 12French (1, 1.3, 1.7, 2, 2.3, 2.7, 3, 3.3, or 4mm) and may have a working length of 20, 30, 40, 60, 80, 100, 120, 150, 180, or 210 cm. Although the following discussion is directed to a catheter for removing tissue in a blood vessel, it should be understood that the teachings of the present disclosure are equally applicable to other types of tissue removal catheters, including but not limited to catheters for penetrating and/or removing tissue in various obstructive, stenotic, or proliferative substances in various body lumens.

Referring to fig. 1-3, a catheter 10 includes an elongated drive coil 12 (generally referred to as an elongated body) disposed about an elongated liner 14. The drive coil 12 and the liner 14 extend along a longitudinal axis LA of the catheter from a proximal portion 16 to a distal portion 18 of the catheter. A tissue-removing element 20 is disposed on the distal end of drive coil 12 and is configured to rotate to remove tissue from a body cavity, as will be explained in more detail below. An insulating sheath 22 is disposed around drive coil 12. Both the drive coil 12 and the liner 14 are configured to translate relative to the isolation sheath 22. The catheter 10 is sized and shaped for insertion into a body cavity of a subject. Isolation sheath 22 isolates the body cavity from at least a portion of drive coil 12 and liner 14. The liner 14 defines a guidewire lumen 24 (fig. 3) for slidably receiving a guidewire 26 therein such that the catheter 10 can be advanced in a body lumen by traveling along the guidewire. The guidewire may be a standard 0.014 inch outer diameter, 300cm long guidewire. In certain embodiments, the liner 14 may have a lubricious inner surface for sliding over the guidewire 26 (e.g., a lubricious surface may be provided by a lubricious polymer layer or lubricious coating). In the illustrated embodiment, the guidewire lumen 24 extends along the entire working length of the catheter 10. In one embodiment, the total working length of the catheter 10 may be between about 135cm (53 inches) and about 142cm (56 inches). In use, the guidewire 26 may extend about 40mm (1.6 inches) beyond the distal end of the liner 14.

Referring to fig. 1 and 4 to 7, the catheter 10 further includes a handle 40 secured at the proximal end of the insulating sheath 22. The handle 40 comprises a housing 41 supporting the components of the handle. The housing 41 has a generally elongated egg shape and contains a plurality of housing sections that are secured together to enclose the internal components of the handle 40. In the illustrated embodiment, the casing 41 includes a bottom casing section 41A, a middle casing section 41B secured to the top of the bottom casing section, and a top casing section 41C secured to the top of the middle casing section. In one embodiment, the bottom housing section 41A is removable from the middle housing section 41B to enable a user to access components of the handle 40 that are inside the housing 41. It is understood that the housing 41 may have other shapes and configurations without departing from the scope of the present disclosure.

Housing 41 supports an actuator 42 (e.g., a lever, button, dial, switch, or other device) configured for selectively actuating a motor 43 disposed in the handle to drive rotation of drive coil 12 and tissue-removing element 20 mounted on the distal end of the drive coil. Motor 43 is configured to rotate drive coil 12 and tissue-removing element 20 at a speed greater than about 80,000 RPM. In one embodiment, motor 43 rotates drive coil 12 and tissue-removing element 20 at a speed of between about 10,000 and about 110,000 RPM. Motor 43 is coupled to drive coil 12 through a gear assembly 44 and a drive assembly 48 supported within housing 41. The gear assembly 44 includes a gear box housing 55 that mounts and at least partially encloses a pair of gears for transmitting rotation of the shaft of the motor 43 to the drive coil 12.

Motor 43 is coupled to drive coil 12 through a gear assembly 44 and a drive assembly 48 supported within housing 41. The gear assembly 44 includes a gear box housing 55 that mounts and at least partially encloses a pair of gears for transmitting rotation of the shaft of the motor 43 to the drive coil 12. The gearbox housing 55 contains a rear housing section 61 and a front housing section 63 integrally formed therewith, such that the gearbox housing comprises a single housing structure (fig. 7). The rear housing section 61 comprises a tube sleeve portion 69 on the proximal side of the rear housing section, which receives the distal end portion of the guide tube 223. The rear housing section 61 is also attached to a bracket or propeller frame 73 for moving the motor 43 and gear assembly 44 within the housing 41. Further, attaching the gearbox housing 55 to the distal end of the thruster frame 73 secures the motor 43 in the thruster frame such that the motor moves along with the thruster frame. The front housing section 63 has a distal sleeve portion that receives a portion of the drive assembly 48. The drive gear 81 is attached to the motor 43 such that when the motor 43 is activated, the drive gear rotates with the motor shaft (fig. 6). The driven gear 83 meshes with the drive gear 81 such that rotation of the drive gear causes the driven gear to rotate in the opposite direction. The drive assembly 48 attaches the driven gear 83 to the drive coil 12 such that rotation of the driven gear causes the drive coil to rotate. A controller 50 may be provided in the handle 40. The controller 50 may be programmed to control the operation of the catheter.

It should be understood that in other embodiments, other suitable actuators, including but not limited to touch screen actuators, wireless controlled actuators, automated actuators guided by a controller, etc., may be adapted to selectively actuate the motor. In some embodiments, the power source may come from a battery (not shown) contained within the handle 40. The battery may provide a current source for the guidewire detection circuit. In other embodiments, the power source may be from an external source.

Referring to fig. 1, 4 and 5, a slide or pusher 45 is positioned on handle 40 and operatively coupled to liner 14 to move the liner relative to the handle to advance and retract the liner, drive coil 12 and tissue-removing element 20. The housing 41 of the handle 40 may define a slot 186 that limits movement of the slider 45 relative to the handle. Thus, the length of the slot 186 determines the amount of relative movement between the liner 14 and the handle 40. In one embodiment, the slot has a length of about 70mm (2.8 inches). The slide 45 is operatively attached to the pusher frame 73 such that movement of the slide causes movement of the pusher frame. The thruster frame 73 comprises an arched body configured to receive the cylindrical motor 43 in a sliding manner. Bearings 149 (fig. 5) are mounted on the frame 73. The bearing 149 is engaged with the housing 41 such that the bearing is slidable along the housing to facilitate movement of the frame 73 within the housing.

Referring to fig. 7A, the guidewire port 47 is mounted on the proximal end of a lock tube 71. In one embodiment, the guidewire port 47 is overmolded onto the locking tube 71. Alternatively, the guidewire port 47 may be press fit onto the latch tube 71. A guide wire port 47 provides structure in the handle 40 to support the guide wire at the proximal end of the handle. The guidewire port 47 defines an axial passage 152 through which the guidewire 26 extends. Additionally, a guidewire lock may be provided in the guidewire port 47 to lock the guidewire 26 in place relative to the handle. The guidewire port 47 may also facilitate flushing of the liner 14 by passing a cannula through the guidewire port and into the liner wedge to allow flushing.

Guide tube 223 extends from gearbox housing 55 at the distal end of the guide tube to coupling sleeve 122 at the proximal end of the guide tube. Guide tube 223 is fixedly attached to gearbox housing 55 and coupling sleeve 122 is fixedly attached to guide tube 223. In one embodiment, coupling sleeve 122 is press fit onto the outer surface of the proximal end of guide tube 223. However, the coupling sleeve 122 may be attached to the guide tube 223 by any suitable means. The coupling sleeve 122 is movably received in the latch tube 71. The engagement between the coupling sleeve 122 and the latch tube 71 permits translation of the coupling sleeve and guide tube 223 relative to the latch tube but prevents rotation of the coupling sleeve and guide tube 223 relative to the latch tube. Specifically, the internal channel in the latch tube 71 provides sufficient clearance to receive the coupling sleeve 122 for axial movement, but does not allow rotational movement of the coupling sleeve within the latch tube. In one embodiment, axial translation of at least about 70mm is permitted.

Referring to fig. 7A through 9, a liner wedge 221 is attached to the proximal end of the liner 14 and received in the coupling sleeve 122, thereby securing the liner wedge to the coupling sleeve. The liner wedge 221 may be secured to the coupling sleeve by any suitable means, including but not limited to, rotational locking, snap fit, friction fit, or press/glue/heat engagement. Thus, movement of the coupling sleeve 122 within the latch tube 71 causes corresponding movement of the liner wedge 221. The liner wedge 221 may also facilitate flushing of the liner 14. The liner 14 extends distally from the liner wedge 221 through the guide tube 223. Liner 14 and liner wedge 221 may be broadly referred to as liner assembly 224. In the illustrated embodiment, the liner wedge 221 includes a locking member 225 and an elongate extension member 227 extending distally from a distal end of the locking member. Passageway 229 extends through liner wedge 221. The proximal end of the liner 14 is attached to the extension member 227 to secure the liner to the liner wedge 221. Thus, the liner wedge 221 and the liner 14 move together as a single unit. In one embodiment, liner 14 is received in a portion of passageway 229 that extends through extension member 227. The liner 14 may be retained in the liner wedge 221 by any suitable means, including but not limited to glue, thermal bonding, and mechanical bonding. In the illustrated embodiment, the locking member 225 comprises a cubic structure including four planar surfaces 241. However, the locking member 225 may have other shapes without departing from the scope of the present disclosure. In one embodiment, locking member 225 has a non-circular or non-rounded outer shape. It is contemplated that the liner wedges 221, guide tubes 223, and latch tubes 71 may have other configurations to permit relative translation and prevent relative rotation. Further, any suitable material may be used for the liner wedge 221, guide tube 223, and latch tube 71. For example, the liner wedge 221 may be formed of Polyetheretherketone (PEEK), Polyoxymethylene (POM), or Polycarbonate (PC).

To assemble the liner assembly 224 in the catheter 10, the liner assembly is inserted into the proximal end 231 of the coupling sleeve 122 to secure the liner assembly to the coupling sleeve. Specifically, the liner 14 is first inserted into the proximal opening 233 of the coupling sleeve 122 and pulled through the distal opening of the coupling sleeve until the liner wedges 221 are positioned adjacent to the proximal opening. As will be explained in more detail below, the coupling sleeve 122 receives the liner wedges 221 within the coupling sleeve by a snap-fit engagement to limit movement of the liner wedges relative to the coupling sleeve. Further, coupling sleeve 122 is configured to allow liner wedge 221 to enter the coupling sleeve at any entry angle and center guide tube 223 within catch tube 71, which in turn centers and aligns liner 14 within drive coil 12. Thus, the liner 14 is prevented from being damaged by the driving coil 12 rotating around the liner.

In the illustrated embodiment, coupling sleeve 122 includes a generally rectangular shaped elongated member having side surfaces 174 defining four planes. The corners of the elongated member are truncated to define four angled corner surfaces 176 connecting adjacent side surfaces 174. Coupling sleeve 122 includes a proximal portion 178 and a distal portion 180 extending distally from the proximal portion. In the illustrated embodiment, the lock section 182 defines the distal portion 180 of the coupling sleeve 122. The lock section 182 defines a wedge opening 183 at a proximal end of the lock section and a wedge channel 185 extending through the lock section from the proximal end of the lock section to a distal end of the lock section. The wedge opening 183 is configured to receive the wedge 221 into the wedge channel 185 when the liner assembly 224 is inserted into the coupling sleeve 122. Arms 184 project radially and axially from a proximal base section 187, together defining a proximal stop surface within coupling sleeve 122. When the liner wedge 221 is inserted into the proximal opening 233 of the coupling sleeve 122, the liner wedge engages the arms 184, deflecting the arms outward to provide clearance for the liner wedge and thereby permit the wedge to move past the arms. After liner wedge 221 is fully inserted into coupling sleeve 122 such that the entire liner wedge is positioned distally of arms 184, the arms move back to their natural state, thereby preventing the liner wedge from being pulled back out of the proximal end of the sleeve. The length of the locking member 225 of the liner wedge 221 is such that the distal end of the locking member engages the proximal end of the guide tube 223, thereby locking the wedge in place within the sleeve 122. Angled entrance surface 194 is located at a proximal end of coupling sleeve 122 and tapers radially inward from side surface 174. Angled surface 194 provides an entry guide at the proximal end of coupling sleeve 122 so that during assembly, liner wedge 221 may be inserted into the proximal end of the coupling sleeve at any angle to secure liner assembly 224 to the coupling sleeve.

First external ribs 196A extend longitudinally along the top and bottom of coupling sleeve 122, and second external ribs 196B extend longitudinally along the sides of the sleeve. Each external rib 196A, 196B generally extends from proximal end 231 of coupling sleeve 122. In the illustrated embodiment, the external ribs 196A, 196B have rounded outer surfaces. The external ribs 196A, 196B provide the coupling sleeve 122 with an effective diameter that provides a close tolerance to the inner diameter of the latch tube 71 to center the sleeve and thereby the liner wedge 221 and liner 14 within the latch tube. Thus, the liner 14 will be centered within the drive coil 12, thereby preventing the liner from being damaged by the drive coil rotating about the liner. It is understood that the coupling sleeve 122 may have other shapes without departing from the scope of the present disclosure. For example, broadly speaking, the coupling sleeve may have a non-circular or non-rounded outer shape. Further, coupling sleeve 122, guide tube 223, gearbox housing 55, and pusher frame 73 may be generally referred to as a coupling assembly for coupling liner assembly 224, including liner 14, to pusher 45.

Referring to fig. 16A and 16B, an alternative embodiment of a coupling assembly is shown. In this embodiment, the coupling sleeves 222, 222 'are directly attached to the gearbox housings 155, 155'. In the illustrated embodiment, the coupling sleeves 222, 222 'are integrally formed with the gearbox housings 155, 155'. However, the coupling sleeves 222, 222 'may be formed separately from the gearbox housings 155, 155' and attached thereto as appropriate. For example, the coupling sleeves 222, 222 'may include adapter portions for attaching the coupling sleeves to the gearbox housings 155, 155'. Thus, the coupling sleeve 222, 222' extends directly from the gearbox housing 155, 155', and the guide tube 323, 323' extends proximally from the coupling sleeve. In addition, coupling sleeves 222, 222' do not include external ribs. In practice, the outer dimensions of the coupling sleeves 222, 222 'are sized for close tolerances inside the locking tubes 171, 171'. Additionally, the sleeves 222, 222' may define proximal and distal stop surfaces to prevent axial movement of a liner wedge received in the sleeve. The coupling assembly otherwise functions substantially the same as the coupling assembly of the previous embodiment.

Referring to fig. 17, another alternative embodiment of a coupling assembly is shown. In this embodiment, the liner wedges 421 include arms 384 that extend laterally across the wedges and are configured for snap-fit engagement with the coupling sleeve 322. Thus, when the liner wedge 421 is inserted into the coupling sleeve 322, the arms 384 are bent inward to provide clearance for the insertion wedge. After the arms are placed in alignment with the side openings 385 in the coupling sleeve 322, the arms 384 flex back to their natural state and remain in the side openings, thereby limiting movement of the wedge 421 relative to the coupling sleeve. The coupling assembly otherwise functions substantially the same as the coupling assembly of the previous embodiment.

Referring to fig. 18, another alternative embodiment of a coupling assembly is shown. In this embodiment, one or more magnets 435 are mounted on the coupling sleeve 422 and are configured to attach to the liner wedge 521 for securing the liner wedge and the liner 314 to the coupling sleeve 422. In one embodiment, the liner wedge 521 is formed of a metal structure such that the liner wedge is attracted to the magnet 435 on the coupling sleeve 422. The coupling assembly otherwise functions substantially the same as the coupling assembly of the previous embodiment.

Referring to fig. 19A-C, another alternative embodiment of a coupling assembly is shown. In this embodiment, coupling sleeve 522 is integrally formed with guide tube 623. In one embodiment, coupling sleeve 522 and guide tube 623 are injection molded together as a unitary structure. However, the components may be formed in other ways without departing from the scope of the present disclosure. In addition, the coupling sleeve 522 includes an arm 584 configured for snap-fit engagement with the liner wedge 621. Thus, when the liner wedge 621 is inserted into the coupling sleeve 522, the arms 584 flex outwardly to provide clearance for the insertion wedge. After the arm 584 is placed in alignment with the recess 585 in the coupling sleeve 522, the arm 584 flexes back to its natural state and remains in the recess, thereby limiting movement of the wedge 621 relative to the coupling sleeve. The coupling assembly otherwise functions substantially the same as the coupling assembly of the previous embodiment.

Additionally or alternatively, the arms of the coupling sleeve may engage the liner wedges with a friction fit. Other configurations for locking the liner wedges to the coupling sleeve/guide tube are also contemplated without departing from the scope of the present disclosure.

Referring to fig. 1 and 3, the isolation sheath 22 comprises a tubular sleeve configured to isolate and protect arterial tissue within a body lumen of a subject from damage by the rotating drive coil 12. The insulating sheath 22 is fixed to the handle 40 at the proximal end of the sheath and does not rotate. The isolation sheath 22 provides a partial enclosure for the drive coil 12 and the liner 14 to move within the sheath. The inner diameter of isolation sheath 22 is sized to provide clearance for drive coil 12. Isolating the space between the sheath 22 and the drive coil 12 allows the drive coil to rotate within the sheath and provides an area for saline perfusion between the sheath and the drive coil. The outer diameter of the isolation sheath 22 is sized to provide clearance in conjunction with the inner diameter of a guiding catheter (not shown) for delivering the catheter 10 to a desired location in a body lumen. In one embodiment, the insulating sheath 22 has an inner diameter of about 0.050 inches (1.27mm), an outer diameter of about 0.055 inches (1.4mm), and a length of about 1500mm (59 inches). The insulating sheath 22 may have other dimensions without departing from the scope of the present disclosure. In one embodiment, the insulating sheath 22 is made of Polytetrafluoroethylene (PTFE). Alternatively, the insulating jacket 22 may comprise a multi-layer construction. For example, the insulation jacket 22 may include an inner layer of Perfluoroalkoxy (PFA), an intermediate braided wire layer, and an outer layer of Pebax.

Referring to fig. 1-3, drive coil 12 may comprise a tubular stainless steel coil configured to transmit rotation and torque from motor 43 to tissue-removing element 20. Configuring drive coil 12 in a coiled configuration allows the rotation and torque of drive coil 12 to be applied to tissue-removing element 20 as catheter 10 is passed through a curved path. The coil configuration of the drive coil 12 is also configured to expand its inner diameter as the coil rotates so that the drive coil remains spaced apart from the liner 14 during operation of the catheter 10. In one embodiment, drive coil 12 has an inner diameter of about 0.023 inches (0.6mm) and an outer diameter of about 0.035 inches (0.9 mm). The drive coil 12 may have a single-layer construction. For example, the drive coil may comprise a 7-filament (i.e., wire) coil having a lay angle of about 30 degrees. Alternatively, drive coil 12 may be configured from multiple layers without departing from the scope of this disclosure. For example, drive coil 12 may include a base coil layer and a sheath (e.g., Tecothane) disposed on the base layer^TM). In one embodiment, the drive coil comprises a 15-wire coil having a lay angle of about 45 degrees. The Tecothane^TMThe sheath may be disposed over the coil. Alternatively, the drive coil 12 may comprise a dual coil layer configuration that also includes an additional outer jacket layer over both coil layers. For example, the drive coil may include an inner coil layer including 15-wire coils having a lay angle of about 45 degrees and an outer coil layer including 19-wire coils having a lay angle of about 10 degrees. Drive coils having other configurations are also contemplated.

Referring to fig. 1-3 and 10, liner 14 includes a multilayer tubular body configured to isolate guidewire 26 from drive coil 12 and tissue-removing element 20. The liner 14 may extend through the handle 40 from a location within the handle to a location distal to the handle. In one embodiment, the liner 14 is coupled to a component within the handle 40 but is not fixedly attached to the housing 41 to allow translation of the liner relative to the housing. The liner 14 has an inner diameter sized to pass a guidewire 26 therethrough. Liner 14 protects the guidewire from damage due to rotation of drive coil 12 by isolating the guidewire from the rotatable drive coil. Liner 14 may also extend past tissue-removing element 20 to protect guidewire 26 from the rotating tissue-removing element. Thus, the liner 14 is configured to prevent any contact between the guidewire 26 and rotating components of the catheter 10. Thus, liner 14 eliminates any metal-to-metal bonding. This isolation of drive coil 12 and tissue removal element 20 from guidewire 26 also ensures that rotation of the drive coil and tissue removal element is not transferred or transmitted to the guidewire. Thus, a standard guidewire 26 may be used with the catheter 10 because the guidewire does not have to be configured to withstand the twisting effects of rotating components. In addition, by extending liner 14 through tissue-removing element 20 and past the distal end of the tissue-removing element, the liner stabilizes the tissue-removing element by providing a central axis for rotation of the tissue-removing element about the liner.

In the illustrated embodiment, the inner liner 14 includes an inner PTFE layer 60, an intermediate braid layer 62 composed of stainless steel, and an outer polyimide layer 64 (fig. 10). The PTFE inner layer 60 provides a lubricious interior to the liner 14, which facilitates passage of the guidewire 26 therethrough. The braided stainless steel intermediate layer 62 provides rigidity and strength to the liner 14 so that the liner can withstand torsional forces exerted on the liner by the drive coil 12. In one embodiment, the intermediate layer 62 is formed from 304 stainless steel. The polyimide outer layer 64 provides wear resistance and has lubricating properties that reduce friction between the inner liner 14 and the drive coil 12. Additionally, a lubricating film, such as silicone, may be added to the lining 14 to reduce friction between the lining and the drive coil 12. In one embodiment, liner 14 has an inner diameter ID of about 0.016 inches (0.4mm), an outer diameter OD of about 0.019 inches (0.5mm), and a length of about 59 inches (1500 mm). The inner diameter ID of the liner 14 provides clearance for a standard 0.014 inch guidewire 26. The outer diameter OD of liner 14 provides clearance for drive coil 12 and tissue-removing element 20. Having a space between the liner 14 and the drive coil 12 reduces friction between the two components and allows saline between the components to perfuse.

Referring to fig. 1, 2 and 11, tissue-removing element 20 extends along longitudinal axis LA from a proximal end adjacent the distal portion of drive coil 12 to an opposite distal end. Tissue-removing element 20 is operatively connected to motor 43 for rotation by the motor. When the catheter 10 is inserted into a body lumen and the motor 43 rotates the tissue-removing element 20, the tissue-removing element is configured to remove occluded tissue in the body lumen to separate the tissue from the body lumen wall. In one or more embodiments, any suitable tissue removal element may be used to remove tissue in the body lumen as it is rotated. In the illustrated embodiment, the tissue removal element 20 comprises an abrading file configured to abrade tissue in the body cavity as the motor 43 rotates the abrading file. The abrasive rasp 20 has an abrasive outer surface formed, for example, by diamond grit coating, surface etching, or the like. In other embodiments, the tissue-removing elements may include one or more cutting elements having smooth or serrated cutting edges, macerators, thrombectomy lines, and the like.

Referring to fig. 12, lumen 72 extends longitudinally through tissue-removing element 20 such that the tissue-removing element defines openings at its proximal and distal ends. Lumen 72 includes a first diameter portion 74 extending distally from the proximal end of tissue-removing element 20 and a second diameter portion 78 extending distally from the first diameter portion, forming a first shoulder 80 disposed between the first diameter portion and the second diameter portion. The third diameter portion 82 extends distally from the second diameter portion 78 and forms a second shoulder 84 between the second diameter portion and the third diameter portion. Fourth diameter portion 86 extends distally from the third diameter portion to the distal end of the tissue-removing element and forms a third shoulder 88 between the third diameter portion and the fourth diameter portion. The diameters of the first diameter portion 74, the second diameter portion 78, the third diameter portion 82, and the fourth diameter portion 86 are constant along their lengths. In the illustrated embodiment, diameter D1 of first diameter portion 74 is greater than diameter D2 of second diameter portion 78, diameter D2 is greater than diameter D3 of third diameter portion 82, and diameter D3 is greater than diameter D4 of fourth diameter portion 86. In one embodiment, the diameter D1 of the first diameter portion 74 is about 0.037 inches (0.95mm), the diameter D2 of the second diameter portion 78 is about 0.035 inches (0.9mm), the diameter D3 of the third diameter portion 82 is about 0.033 inches (0.85mm), and the diameter D4 of the fourth diameter portion 86 is about 0.031 inches (0.8 mm). Other cross-sectional dimensions are also contemplated without departing from the scope of the present disclosure.

Liner 14 extends through drive coil 12 and past the distal end of tissue-removing element 20. Fourth diameter portion 86 of cavity 72 is sized to allow liner 14 to pass through with small voids. Inner diameter D4 provides clearance between tissue-removing element 20 and liner 14 to reduce friction between the components. Thus, tissue-removing element 20 is shaped and arranged to extend around at least a portion of drive coil 12 and liner 14 and thus provide a relatively compact assembly for abrading tissue at the distal portion of catheter 10.

Referring to fig. 11 through 13, a sleeve 90 is received in cavity 72 of tissue-removing element 20 and surrounds liner 14. The bushing 90 includes a central ring portion 92, a proximal ring portion 94 extending proximally from the central ring portion, and a distal ring portion 96 extending distally from the central ring portion. The ring portion of the liner 90 defines a passageway 99 extending through the liner that receives a portion of the liner 14. In the illustrated embodiment, the central ring portion 92 has a larger outer diameter than the proximal ring portion 94 and the distal ring portion 96. Center ring portion 92 is disposed in second diameter portion 78 of lumen 72, proximal ring portion 94 is disposed in first diameter portion 74, and distal ring portion 96 is disposed in second diameter portion 78 and third diameter portion 82. In one embodiment, the bushing 90 is made of Polyetheretherketone (PEEK) and Polytetrafluoroethylene (PTFE). However, the bushing 90 may be formed from other materials without departing from the scope of the present disclosure.

Referring to fig. 11, 14 and 15, a first bearing 98 is disposed about the proximal ring portion 94 of the bearing 90 and a second bearing 100 is disposed about the distal ring portion 96 of the bearing. The outer diameter D5 of the first bearing 98 is greater than the outer diameter D6 of the second bearing 100. In one embodiment, the bearings 98, 100 are made of zirconia. First bearing 98 is disposed in alignment with first diameter portion 74 of cavity 72 in tissue-removing element 20 and is located between the distal end of drive coil 12 at the proximal end of the first bearing and central ring portion 92 and first shoulder 80 of bushing 90 at the distal end of the first bearing. The second bearing 100 is positioned in alignment with the second diameter portion 78 of the cavity 72 and between the second shoulder 84 at the distal end of the second bearing and the central ring portion 92 of the bushing 90 at the proximal end of the second bearing. Thus, bushing 90 and bearings 98, 100 are retained within cavity 72 of tissue-removing element 20. In general terms, the bushing 90 and bearings 98, 100 may be considered a coupling assembly 57 for coupling the liner 14 to the tissue-removing element 20.

Referring to fig. 11, the inner surface of liner 90 is fixedly attached to liner 14 such that the liner is coupled to tissue-removing element 20 through the liner. In one embodiment, an adhesive, such as an epoxy glue, joins the liner 90 to the liner 14. Thus, liner 90 does not rotate about liner 14. Drive coil 12 is directly and fixedly attached to tissue-removing element 20. Tissue-removing element 20 may be fixedly attached to the distal end of drive coil 12 by any suitable means. In one embodiment, an adhesive joins drive coil 12 to tissue-removing element 20. The drive coil 12 is received in the first diameter portion 74 of the cavity 72 with the distal end of the drive coil abutting the first bearing 98. However, liner 14 is not directly attached to tissue-removing element 20, and drive coil 12 is not directly attached to bushing 90, bearings 98, 100, or the liner. Thus, rotation of drive coil 12 and tissue-removing element 20 is not transmitted to liner 14 to also rotate the liner. In effect, tissue-removing element 20 rotates about bushing 90 and bearings 98, 100. Also, because the liner is fixedly attached to the sleeve 90, which is held within the cavity 72 of the tissue-removing element 20 by the drive coil 12, the liner 14 is coupled to the drive coil and the tissue-removing element by a sleeve and bearing arrangement.

Further, and referring to fig. 5 and 7A, attaching the guide tube 223 to the gearbox housing 55 in a fixed manner and attaching the gearbox housing to the distal end of the thruster frame 73 couples the liner assembly 224 to the thruster frame such that the liner assembly moves along with the thruster frame. Thus, liner 14, rather than drive coil 12, provides the primary pushing and pulling forces to tissue-removing element 20 as pusher 45 is moved relative to handle 40. Thus, movement of pusher 45 causes direct translational movement of liner 14, which is then transferred to drive coil 12 and tissue-removing element 20. This configuration utilizes the structure of the liner 14 to transmit pushing and pulling forces to the distal end of the catheter 10. The stiffness of liner 14 is particularly suited to efficiently transfer push-pull forces to tissue-removing element 20 without experiencing the force transfer and frictional losses that may occur when using rotary drive coil 12 to provide both push and pull forces. Thus, a direct 1:1 coupling of the pusher 45 with the tissue-removing element 20 is achieved. This also allows for a more flexible drive coil 12 to be used, as the drive coil is not used to transfer the movement of the pusher 45 to the distal end of the catheter 10.

Referring to fig. 1 and 2, to remove tissue in a subject body lumen, a practitioner inserts a guidewire 26 into the subject body lumen to a location distal of the tissue to be removed. The practitioner then inserts the proximal end portion of the guidewire 26 through the guidewire lumen 24 of the liner 14 and through the handle 40 such that the guidewire extends through the proximal port 47 in the handle. As the catheter 10 is loaded onto the guidewire 26, the practitioner advances the catheter along the guidewire until the tissue-removing element 20 is positioned proximal and adjacent to the tissue. When tissue-removing element 20 is positioned proximal to and adjacent to the tissue, the practitioner actuates motor 43 using actuator 42 to rotate drive coil 12 and the tissue-removing element mounted thereon. Tissue-removing element 20 abrades (or otherwise removes) tissue in the body lumen as it rotates. As tissue-removing element 20 is rotated, the practitioner may selectively move drive coil 12 and liner 14 distally along guidewire 26 to abrade tissue and, for example, increase the size of the passage through the body lumen. The practitioner may also move drive coil 12 and liner 14 proximally along guidewire 26, and may repeatedly move the components in the distal and proximal directions by sliding pusher 45 back and forth within slot 186 in handle 40 to effect an anterior-posterior movement of tissue-removing element 20 across the tissue. Because the coupling between the pusher 45 and the tissue-removing element 20 to transfer force from the pusher to the tissue-removing element is performed by the relatively stiff inner liner 14, the practitioner is able to have a greater degree of control over the movement of the tissue-removing element 20. Thus, there is no lost motion between the movement of the advancer 45 and the corresponding movement of the tissue-removing element 20. During the abrading process, bushing 90 and bearings 98, 100 couple liner 14 to tissue-removing element 20 and allow drive coil 12 and the tissue-removing element to rotate about the liner. Liner 14 also isolates guidewire 26 from rotating drive coil 12 and tissue-removing element 20 to protect the guidewire from damage by rotating components. As such, liner 14 is configured to withstand the torsional and frictional effects of rotating drive coil 12 and tissue-removing element 20 without transferring these effects to guidewire 26. In addition, the coupling of the liner 14 and the tissue-removing element 20 allows movement of the liner, such as translational movement within a body cavity, to be transmitted to the drive coil 12 and the tissue-removing element so that the drive coil and the tissue-removing element move with the liner through the body cavity. When the practitioner is finished using the catheter 10, the catheter may be withdrawn from the body cavity and unloaded from the guidewire 26 by sliding the catheter proximally along the guidewire. The guidewire 26 used for the abrasion procedure may be retained in the body lumen for subsequent procedures.

When introducing elements of the present invention or one or more embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

As various changes could be made in the above devices, systems, and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.