CN117337157A

CN117337157A - Aspiration devices including expandable distal ends for treatment of thrombosis and systems and methods thereof

Info

Publication number: CN117337157A
Application number: CN202280032128.9A
Authority: CN
Inventors: S·J·巴隆; M·罗森塔尔; D·斯诺; B·多梅克斯; T·勒
Original assignee: Endovascular Engineering Co ltd
Current assignee: Endovascular Engineering Co ltd
Priority date: 2021-03-01
Filing date: 2022-02-28
Publication date: 2024-01-02

Abstract

Systems, devices, and methods for treating thrombosis are described herein. In some embodiments, the apparatus may include a cannula defining a first lumen and an aspiration catheter defining a second lumen, the aspiration catheter slidably disposed within the first lumen. The aspiration catheter may include: a proximal end coupleable to a vacuum source configured to apply vacuum pressure within the second lumen to draw thrombus into the second lumen; and an expandable end configured to transition between a retracted configuration in which the expandable end is constrained within the cannula and an expanded configuration in which at least a portion of the expandable end is disposed distal of the cannula. The expandable tip in the expanded configuration may have a funnel-shaped profile with a diameter that gradually increases from a proximal end of the expandable tip to a distal end of the expandable tip.

Description

Aspiration devices including expandable distal ends for treatment of thrombosis and systems and methods thereof

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application 63/155,191 filed on day 3, 2021 and U.S. provisional application 63/170,346 filed on day 4, 2021, the disclosures of each of which are incorporated herein by reference in their entirety.

Technical Field

Embodiments described herein relate generally to systems, devices, and methods for treating thrombosis, including treating pulmonary embolism.

Background

Thrombosis refers to the formation of blood clots within blood vessels that may impede the flow of blood through the circulatory system. Thrombosis may occur in any artery or vein within the heart or body, leading to a variety of medical problems such as myocardial infarction, stroke, pulmonary embolism, and deep vein thrombosis. A rapid thrombectomy is often required in the following cases: 1) Arterial blockage of fragile organs such as the heart or brain (e.g., ischemic stroke); 2) Large clots disrupt blood flow in the main vessel or cause severe symptoms; or 3) when the risk of systemic administration of the drug is too great.

Conventional thrombectomy devices for removing clots from an occluded vessel include mechanical thrombectomy devices, such as aspiration catheters. However, aspiration catheters may be ineffective for large clot loading, organized (e.g., tough) clots, and clots that extend from large vessels to small vessels. Other mechanical thrombectomy devices, including those having a distal cutting or maceration mechanism disposed directly in the lumen of the vessel, can result in distal embolization of the clot and vascular damage. Accordingly, improved systems, devices, and methods for removing substances (e.g., blood clots) from a patient's vasculature are desired.

Disclosure of Invention

Systems, devices, and methods for treating thrombosis are described herein. In some embodiments, an apparatus may include a cannula defining a first lumen and a suction catheter defining a second lumen slidably disposed within the first lumen, the suction catheter comprising: a proximal end coupleable to a vacuum source configured to apply vacuum pressure within the second lumen to draw thrombus into the second lumen; and an expandable end configured to transition between a retracted configuration in which the expandable end is constrained within the cannula and an expanded configuration in which at least a portion of the expandable end is disposed distal of the cannula. The expandable tip in the expanded configuration may have a funnel-shaped profile with a diameter that gradually increases from a proximal end of the expandable tip to a distal end of the expandable tip. At or near the patient's temperature (e.g., about 35 ℃ to about 40 ℃), the expandable end in the expanded configuration may have a clamping strength of about 0.4lb to about 3lb such that the expandable end in the expanded configuration is configured to withstand collapse due to a pressure gradient within the expandable end resulting from a vacuum pressure acting on a thrombus within the expandable end. The expandable end in the expanded configuration may be further configured to retract into the cannula in response to a retraction force of about 0.5lbs to about 4.0 lbs.

In some embodiments, the clamping strength of the expandable end in the expanded configuration may be about 0.4lb to about 3.0lb. In some embodiments, the retractive force used to retract the expandable end into the cannula may be about0.5lb to about 2.0lb. In some embodiments, the expandable distal tip may include a metal frame and a coating disposed on the metal frame. In some embodiments, the metal frame defines a plurality of openings, and the coating is an inner layer and an outer layer that are connected to each other at the plurality of openings. In some embodiments, each aperture of the plurality of apertures has at least about 0.5mm ² Such that the inner layer and the outer layer of the coating are capable of being connected to each other at each aperture.

In some embodiments, the expandable distal tip may include a metal frame defining a plurality of openings that increase in size from the proximal end to the distal end of the expandable tip. In some embodiments, the metal frame may further comprise an atraumatic wave-shaped (e.g., U-shaped, wavy) ring at the distal end of the expandable tip. In some embodiments, when the expandable tip is in the retracted configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip may have a length of at least about 2.0mm, and an aperture of the plurality of apertures disposed at the distal end of the expandable tip may have a length of less than about 5.0 mm. In some embodiments, when the expandable tip is in the expanded configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip may have a proximal angle of at least about-10 ° and an aperture of the plurality of apertures disposed at the distal end of the expandable tip may have a proximal angle of less than about 40 °.

In some embodiments, the aspiration catheter defines a plurality of openings disposed near the proximal end of the expandable tip, the plurality of openings configured to increase fluid available for mixing with thrombus to improve flow of thrombus proximally through the second lumen. In some embodiments, a flexible shaft may have a distal end disposable within the expandable tip of the aspiration catheter, the distal end of the flexible shaft configured to rotate within the expandable tip when the expandable tip is in the expanded configuration to engage and disrupt portions of a thrombus disposed within the expandable tip.

In some embodiments, an apparatus may comprise: a cannula defining a first lumen and an aspiration catheter defining a second lumen, the aspiration catheter including a proximal end coupleable to a vacuum source configured to apply vacuum pressure within the second lumen to aspirate thrombus from the vessel into the second lumen; an expandable tip positionable within the vessel, the expandable tip being configured to transition between a retracted configuration in which the expandable tip is constrained within the cannula and an expanded configuration in which at least a portion of the expandable tip is disposed distal of the cannula, the expandable tip in the expanded configuration may have a funnel-shaped profile with a diameter that gradually increases from a proximal end of the expandable tip to a distal end of the expandable tip; and an elongate body extending between the proximal end of the suction catheter and the proximal end of the expandable tip. The elongate body may have a linear proximal section and a flexible bending section disposed near the expandable tip, the elongate body configured to translate within the first lumen, the elongate body coupled to an actuator configured to selectively control the extent of extension of the memory setting bending section from the distal end of the cannula to vary the degree of bending of the memory setting bending section and the position of the expandable tip within the vessel.

In some embodiments, the elongate body may be further configured to rotate within the first lumen to change the position of the expandable end within the vessel. In some embodiments, the memory-setting curved section is configured to have a radius of curvature of about 10mm to about 40mm when extending at least partially from the distal end of the cannula. In some embodiments, the sleeve may have a curved section. In some embodiments, the elongate body may be further configured to rotate within the first lumen to change the relative orientation of the memory-set bending section with respect to the bending section of the cannula such that the total angular deviation of the aspiration catheter may be adjusted. In some embodiments, the expandable distal tip may include a metal frame and a coating disposed on the metal frame. In some embodiments, the expandable distal tip may include a metal frame defining a plurality of openings that increase in size from the proximal end to the distal end of the expandable tip.

In some embodiments, the metal frame may further comprise an atraumatic wave ring at the distal end of the expandable tip. In some embodiments, when the expandable tip is in the retracted configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip may have a length of about 2mm, and an aperture of the plurality of apertures disposed at the distal end of the expandable tip may have a length of about 5 mm. In some embodiments, when the expandable tip is in the expanded configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip may have a proximal angle of about-10 °, and an aperture of the plurality of apertures disposed at the distal end of the expandable tip may have a proximal angle of about 40 °. In some embodiments, a flexible shaft has a distal end disposable within the expandable tip of the aspiration catheter, the distal end of the flexible shaft configured to rotate within the expandable tip when the expandable tip is in the expanded configuration to engage and disrupt a portion of a thrombus disposed within the expandable tip.

In some embodiments, the system may comprise: an aspiration catheter defining a lumen, the aspiration catheter including a proximal end coupleable to a vacuum source configured to apply vacuum pressure within the lumen to aspirate thrombus from a vessel into the lumen; an expandable tip configured to transition between a retracted configuration in which the expandable tip is constrained within the outer cannula and an expanded configuration in which at least a portion of the expandable tip is disposed distally of the outer cannula, the expandable tip in the expanded configuration having a funnel-shaped profile with a diameter that gradually increases from a proximal end of the expandable tip to a distal end of the expandable tip; a flexible shaft positionable within the lumen of the aspiration catheter, the flexible shaft configured to extend from the proximal end of the aspiration catheter to the expandable tip such that a distal end of the flexible shaft is disposed within the expandable tip, the distal end of the flexible shaft having a non-linear configuration and being configured to rotate within the expandable tip when the expandable tip is in the expanded configuration to engage and disrupt a portion of a thrombus disposed within the expandable tip.

In some embodiments, a handle assembly may be coupled to the proximal end of the aspiration catheter, the handle assembly including a set of actuators for independently rotating the aspiration catheter and/or translating the outer sleeve relative to the aspiration catheter. In some embodiments, a drive system may be coupled to the proximal end of the flexible shaft and configured to rotate the flexible shaft, the drive system being releasably coupleable to the handle assembly.

In some embodiments, the activation element may be configured to activate the vacuum pressure and activate the drive system to rotate the flexible shaft. In some embodiments, the activation element may be a button configured to (1) activate the vacuum pressure in response to being pressed a first amount, and (2) activate the drive system in response to being pressed a second amount that is greater than the first amount. In some embodiments, the outer sleeve and the aspiration lumen define an annular space configured to deliver fluid into a region proximate to the thrombus.

In some embodiments, an apparatus may comprise: a handle assembly; a catheter extending distally from the handle assembly and having an expandable distal tip, the catheter being positionable within a body lumen adjacent to a thrombus; a cannula disposed over at least a portion of the catheter including the expandable distal tip; a vacuum port coupled to the handle assembly and configured to be coupled to a vacuum source such that a negative pressure can be applied to the lumen of the catheter; an adjustment mechanism coupled to the handle assembly and configured to move at least one of the catheter or the cannula relative to each other such that the expandable distal tip is movable between a first position within the cannula and a second position distal of the cannula. In some embodiments, the expandable distal tip may be configured to have an unexpanded configuration in the first position and an expanded configuration in the second position. The expandable distal tip in the expanded configuration may have a maximum diameter that is greater than a diameter of the cannula. The expandable distal tip may be configured to remain in the expanded configuration upon application of negative pressure to the lumen of the catheter such that thrombus may be aspirated into the expandable distal tip.

In some embodiments, the expandable distal tip may include a plurality of sections, each section of the plurality of sections having a different structure. In some embodiments, the expandable distal tip may be formed from a metallic tubular member, each section of the plurality of sections having a different cutting pattern. In some embodiments, each of the plurality of sections may have a different strength such that a more distal section of the plurality of sections has a greater strength than a more proximal section of the plurality of sections.

In some embodiments, the expandable distal tip may include a bend such that a distal opening of the expandable distal tip is angled relative to a longitudinal axis of the catheter. In some embodiments, the adjustment mechanism may be a first adjustment mechanism, the apparatus further comprising: a second adjustment mechanism configured to rotate the catheter such that the expandable distal tip is rotatable to position the distal opening of the expandable distal tip at different lateral positions relative to the longitudinal axis of the catheter. In some embodiments, the second adjustment mechanism may be a roller or knob. In some embodiments, the adjustment mechanism may be a slider, roller, or knob.

In some embodiments, the expandable distal tip in the expanded configuration may have a funnel shape. In some embodiments, the expandable distal tip in the expanded configuration may have a plurality of stepped sections, each stepped section of the plurality of stepped sections having a different diameter, wherein a more distal stepped section has a larger diameter than a more proximal stepped section.

In some embodiments, a system may include an apparatus as described in embodiments herein and a shaft assembly comprising: a flexible shaft positionable within a lumen of a catheter, the flexible shaft comprising a distal end configured to be positioned proximally of the distal end of the catheter within the expandable distal tip, the flexible shaft configured to rotate such that when negative pressure is applied to the lumen of the catheter, the distal end of the flexible shaft is rotatable axially about a longitudinal axis of the flexible shaft and orbitally about the longitudinal axis of the catheter to cause thrombus to rupture and be aspirated proximally within the lumen of the catheter.

In some embodiments, the shaft assembly may further comprise: a stylet positionable within a lumen of the flexible shaft, the stylet including a shaped distal end having a greater bending stiffness than at least a portion of the flexible shaft such that the shaped distal end can impart a shape to the flexible shaft when disposed within the lumen of the flexible shaft, the shaft and stylet being configured to be rotated such that the distal end of the flexible shaft is axially rotatable about the longitudinal axis of the flexible shaft and orbitally rotatable about the longitudinal axis of the catheter. In some embodiments, the drive system is configured to rotate the shaft.

In some embodiments, the method may comprise: navigating a distal end of the aspiration catheter within the vessel to a site including a thrombus; expanding the distal end of the aspiration catheter; navigating a distal end of the flexible shaft through a lumen of the aspiration catheter; positioning the distal end of the flexible shaft proximal to the distal end of the aspiration catheter; applying vacuum pressure to the lumen of the aspiration catheter such that thrombus is aspirated into the expanded distal end of the aspiration catheter; and rotating the flexible shaft using a drive system to remodel and aspirate thrombus proximally within the lumen of the aspiration catheter.

In some embodiments, expanding the distal end of the aspiration catheter may include moving at least one of a cannula disposed on the distal end of the catheter or the catheter relative to the other to allow the distal end of the catheter to self-expand. In some embodiments, the method can include navigating a stylet having the flexible shaft through the lumen of the aspiration catheter, the stylet including at least a portion disposable within the lumen of the flexible shaft, and rotating the stylet with the flexible shaft using the drive system.

In some embodiments, an apparatus may comprise: a flexible shaft positionable within a lumen of an aspiration catheter positionable within a vessel adjacent to a thrombus; a stylet positionable within a lumen of the flexible shaft, the stylet including a shaped distal end having a bending stiffness greater than at least a portion of the flexible shaft such that the shaped distal end can impart a shape to the flexible shaft when disposed within the lumen of the flexible shaft; and a drive system coupleable to the flexible shaft and the stylet, the drive system configured to rotate the flexible shaft and the stylet such that a distal end of the flexible shaft is capable of remodelling a thrombus to enable the thrombus to be inhaled proximally within the lumen of the aspiration catheter.

In some embodiments, the drive system may be configured to independently rotate the flexible shaft and the stylet such that the flexible shaft may rotate at a first speed and the stylet may rotate at a second speed different from the first speed.

In some embodiments, the drive system may include a first motor coupled to the flexible shaft and a second motor coupled to the stylet. In some embodiments, when the shaped distal end of the stylet is disposed in the flexible shaft, the flexible shaft may be configured to orbitally rotate about the longitudinal axis of the aspiration catheter in response to rotation of the stylet by the drive system. In some embodiments, the stylet may be configured to rotate about a longitudinal axis of the flexible shaft. In some embodiments, the distal end of the flexible shaft may be a closed distal end such that the stylet cannot extend distally to the distal end of the flexible shaft.

In some embodiments, the distal end of the flexible shaft may include an aperture configured to slidably receive a guidewire. In some embodiments, the stylet may further include a lumen configured to receive the guidewire. In some embodiments, the stylet is removable from the lumen of the flexible shaft such that the lumen of the flexible shaft is capable of receiving the guidewire.

In some embodiments, the handle assembly may be configured to house the drive system. In some embodiments, the handle assembly may include one or more seals configured to prevent leakage of vacuum pressure applied within the lumen of the aspiration catheter. In some embodiments, the handle assembly may include one or more actuation elements configured to be manipulated by a user to control the drive system to rotate the flexible shaft and the stylet.

In some embodiments, the method may comprise: navigating a distal end of the aspiration catheter within the vessel to a site including a thrombus; navigating a distal end of a flexible shaft and a stylet through a lumen of the aspiration catheter, the stylet including at least a portion disposable within the lumen of the flexible shaft; positioning the distal end of the flexible shaft proximal to the distal end of the aspiration catheter; applying vacuum pressure to the lumen of the aspiration catheter; and rotating the flexible shaft and the stylet using a drive system to remodel and draw thrombus proximally into the lumen of the aspiration catheter.

In some embodiments, the method may comprise: rotating the flexible shaft and the stylet includes rotating the flexible shaft using a first drive mechanism of the drive system and rotating the stylet using a second drive mechanism of the drive system. In some embodiments, rotation of the stylet using the second drive mechanism can be independent of rotation of the flexible shaft using the first drive mechanism such that the stylet and the flexible shaft can rotate at different speeds. In some embodiments, the method may include initiating application of vacuum pressure to the lumen of the aspiration catheter prior to rotating the flexible shaft and the stylet. In some embodiments, the distal end of the flexible shaft and the stylet may be navigated to the site after the distal end of the aspiration catheter has been navigated to the site.

Drawings

Fig. 1 is a diagram of a pulmonary embolism in a patient's vasculature according to an embodiment.

Fig. 2A and 2B are schematic illustrations of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 3 is a schematic view of a shaft assembly of a thrombectomy system according to an embodiment.

Fig. 4 is a schematic view of the distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 5 is a cross-sectional side view of a thrombectomy system including a catheter and shaft assembly according to an embodiment.

Fig. 6 is a cross-sectional side view of a thrombectomy system including a catheter and shaft assembly according to an embodiment.

Fig. 7A and 7B are detailed side cross-sectional views of a catheter and shaft assembly of a thrombectomy system according to an embodiment.

Fig. 8A and 8B are front cross-sectional views of a catheter and shaft assembly of a thrombectomy system according to an embodiment.

Fig. 9 is a side view of the distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 10 is a side view of the distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 11A-11C are cross-sectional side views of a distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 12A-12C are cross-sectional side views of a distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 13A and 13B are cross-sectional side views of a distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 14A-14D are images of a distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 15A-15E are schematic illustrations of a distal end of a catheter assembly of a thrombectomy system according to an embodiment.

Fig. 16A and 16B are images of a thrombectomy system navigated through a simulated vasculature according to an embodiment.

Fig. 17A is a cross-sectional side view of a handle of a thrombectomy system according to an embodiment. Fig. 17B is a cross-sectional perspective view of the handle of the thrombectomy system depicted in fig. 17A. Fig. 17C and 17D are additional cross-sectional perspective views of the handle of the thrombectomy system depicted in fig. 17A.

Fig. 18A-18B are images of a handle of a thrombectomy system according to an embodiment.

Fig. 19 is a perspective view of a handle of a thrombectomy system according to an embodiment.

Fig. 20A-20B are images of a handle of a thrombectomy system according to an embodiment.

Fig. 21A-21D are images of a distal end of a catheter assembly of a thrombectomy system, according to an embodiment, in an expanded configuration. Fig. 21E shows a view of the distal end of the catheter assembly cut and laid flat.

Fig. 22A and 22B are flowcharts of a method of performing a thrombectomy procedure according to an embodiment.

Fig. 23A-23E are cross-sectional side views of a method of performing a thrombectomy procedure according to an embodiment.

Fig. 24 schematically depicts an arrangement for determining a clamping strength of a distal end of a catheter assembly of a thrombectomy system, according to an embodiment.

Detailed Description

Described herein are systems, devices, and methods for removing a substance (e.g., a blood clot) from a vessel of a subject. The systems, devices, and methods described herein include an aspiration catheter having an expandable tip and a shaft disposable within the aspiration catheter, the shaft configured to rotate and facilitate thrombus uptake and removal. In some embodiments, the rotating shafts described herein may be configured to generate hydrodynamic forces that facilitate proximal movement of the thrombus. The systems and devices described herein may be designed to be compact and flexible to enhance navigation and manipulation of acute pulmonary embolism. For example, the thrombectomy devices described herein may include a low profile (e.g., less than about 16 French) configured to navigate through the heart and have the ability to effectively remove large volumes of thrombus (e.g., up to about 400 ml) with short surgical times.

In some embodiments, the systems, devices, and methods described herein can be used to remove an embolism (e.g., a blood clot) as shown in fig. 1. In some embodiments, the systems, devices, and methods described herein can be used to remove emboli (e.g., blood clots) within a larger body vessel, for example, for treating pulmonary embolism.

In some embodiments, a thrombectomy system as described herein may include a shaft disposed within a lumen of an aspiration catheter. The shaft may be configured for high speed rotation that may produce a combination of axial rotation and orbital motion around the inner circumference of the catheter at the end of the shaft. In some embodiments, the tip of the shaft may be disposed within a larger section of the aspiration catheter (e.g., an expandable tip). In such embodiments, the distal end of the shaft may be configured to engage and remodel the clot, thereby facilitating proximal withdrawal of the clot from the body. In some embodiments, the distal end of the shaft, in response to being rotated, can create a pressure differential in combination with a vacuum created by the aspiration catheter to draw the clot proximally within the catheter lumen. The rotating shaft may form or exhibit a generally helical shape configured to facilitate clot removal by physically remodelling the clot (e.g., compressing, destroying, twisting, elongating) and/or reducing friction along the inner diameter of the catheter (e.g., by wiping the clot off the inner diameter of the catheter). The helical shape may produce a combination of motion at the end of the shaft, including orbital motion about the longitudinal axis of the aspiration catheter and rotational motion about the longitudinal axis of the shaft. The orbital movement of the shaft may reduce or prevent stiction, as well as remodel the clot to enable ingestion. The orbital motion may further exert hydrodynamic and direct mechanical forces on the clot at a lower relative velocity. Suitable examples of such aspiration catheter systems are described in International application Ser. No. PCT/US2019/026737, entitled "HYDRODYNAMIC VORTEX ASPIRATION CATHETER", filed on 10/4/2019, and U.S. Ser. No. 63/155,191, entitled "SYSTEMS, DEVICES, AND METHODS FOR REMOVING THROMBOEMBOLIC MATERIAL WITH COAXIAL INDEPENDENT ROTATIONAL ELEMENTS", filed on 1/3/2021, the disclosures of each of which are hereby incorporated by reference in their entirety.

The systems, devices, and methods described herein may be used to produce a combined orbital and rotational motion of a shaft at any desired speed within a suction catheter. In some embodiments, the systems, devices, and methods may be well suited for removing obstructive material (e.g., blood clots) from one or more vessels of the pulmonary artery. For example, the systems and devices described herein enable removal of thrombus by aspiration through a large diameter vessel. For example, the diameter of the pulmonary veins may vary significantly (e.g., about 4mm to about 24 mm) and may change diameter abruptly. Clot loading and composition may also be variable, and access may not be standardized.

In some embodiments, high speed rotation of the shaft about its longitudinal axis is used to induce the helical shape of the shaft and produce orbital and rotational movement of the shaft. This method of generating orbital and rotational motion of the shaft may have certain drawbacks. For example, the generation of the orbital motion may depend on the speed of axial rotation, torque load on the shaft caused by friction with the obstructing material (e.g., clot) and with the inner surface of the aspiration catheter, the stiffness of the shaft, and other factors. Furthermore, in practice, a rather high speed is required to ensure that the shaft orbits, especially when traversing more tortuous anatomy. Such high speeds increase the risk of catheter torsional failure and loss of vacuum seal, as well as increased vibration, noise, and heating.

Thus, in some embodiments, a thrombectomy system may include a shaped shaft, e.g., a shaft having a bent, curved, or other non-linear portion. The nonlinear portion of the shaft may be disposed near or at the distal end of the shaft such that when the shaft is rotated, the nonlinear portion may facilitate orbital and rotational movement of the shaft. In some embodiments, the nonlinear portion of the shaft may be positioned within the enlarged distal end of the aspiration catheter (e.g., an expandable tip, such as a funnel-shaped tip) such that the end of the shaft may engage and remodel thrombus captured within the enlarged distal end of the aspiration catheter.

Alternatively, in some embodiments, the system may include an aspiration catheter, a shaft, and a shaped stylet or second shaft disposed within and/or about the shaft. The shaped stylet may be configured to cause the shaft to assume a non-linear shape, e.g., having a bent, curved, or other non-linear portion. The shaft may be coupled to a first drive mechanism that controls rotational movement of the shaft about its longitudinal axis. The stylet (e.g., a second shaft disposed within the shaft) can be coupled to a second drive mechanism that controls orbital movement of the shaft about the longitudinal axis of the aspiration catheter. Alternatively, in some embodiments, the stylet and shaft may be coupled to the same drive mechanism but use different coupling elements (e.g., different gears setting different gear ratios), which allow rotational movement to be different than orbital movement. The stylet may be shaped to impart a shape on the shaft that causes orbital movement of the shaft when the stylet is rotated. In some embodiments, the system may be configured to generate an orbital motion of the shaft within the catheter independent of axial rotation of the shaft. For example, the speed and/or direction of the orbital motion may be controlled independently of the speed and/or direction of the axial rotation. The systems, devices, and methods described herein may facilitate clot removal at lower axial rotational speeds, for example, because the shaft does not need to rotate at high speeds to cause orbital motion. With such systems, devices, and methods, orbital motion may also be substantially independent of torque loading and friction.

In some embodiments, a stylet as described herein can be disposed within a lumen of a rotating shaft. The stylet may be configured to rotate within the shaft lumen to produce orbital movement of the shaft within the catheter lumen. The shaft may be configured to rotate simultaneously with the stylet rotation to produce a combined orbital and rotational motion of the shaft (e.g., along a distal portion of the shaft). Movement of the shaft may cause the shaft to mechanically interact with portions of the occluding material (e.g., blood clot) in the aspiration catheter to remodel the occluding material. For example, the shaft may perform rotational and orbital movements (e.g., including a spiral-like shape), which may cause the occluding substance drawn into the lumen of the aspiration catheter to separate from the inner wall of the catheter and prevent accumulation of static friction between the occluding substance and the catheter. In the case of orbital movement of the stylet drive shaft, the axial rotational speed of the shaft may be reduced. This may enable the use of less complex drive systems and increase the reliability of the system.

In some embodiments, the aspiration catheter, shaft, and/or stylet are movable (e.g., translatable) relative to one another along a longitudinal axis of the system. In some embodiments, one or more locking mechanisms (e.g., stops, clamps, etc.) may be configured to limit translation of one or more of the shaft or stylet relative to the catheter. In some embodiments, the shaft and/or stylet may have a fixed or predetermined length such that the shaft and/or stylet may be inserted into the aspiration catheter up to a predetermined depth (e.g., advanced to a predetermined position relative to the aspiration catheter).

In some embodiments, the aspiration catheter may include a distal tip configured to transition from a first configuration (e.g., a retracted or compressed configuration) in which the distal tip has a first diameter to a second configuration (e.g., an expanded configuration) in which the distal tip has a second diameter that is greater than the first diameter. In such embodiments, the larger expanded end of the aspiration catheter may be configured to aspirate at least a portion of a clot or thrombus within the vessel into the tip of the aspiration catheter. The shaft disposed within the aspiration catheter may then be used to engage and remodel the clot or thrombus to facilitate proximal movement of the clot or thrombus. Such embodiments may be particularly useful for pulmonary embolism applications involving vessels of larger diameter, and thus removal of larger clots and thrombi. The larger distal end of the aspiration catheter may be configured to capture larger clots and thrombi, while the rotational shaft within the aspiration catheter may be configured to remodel clots and thrombi so that they may be aspirated out through the lumen of the aspiration catheter.

In some embodiments, the aspiration catheter may include other non-linear portions that are bent, curved, or impart an angle to the tip of the aspiration catheter. For example, the aspiration catheter may include a bend disposed adjacent or near a larger distal end (e.g., an expandable distal tip, such as a funnel-shaped tip) of the aspiration catheter, and the amount of curvature may be indicative of the direction in which the distal end of the aspiration catheter is directed. Such bending or other non-linearities of the aspiration catheter may facilitate navigation of the aspiration catheter and/or searching for clots. In some embodiments, the degree of bending or nonlinearity of the aspiration catheter can be controlled using an external cannula. The outer sleeve may have a greater strength than the suction catheter and may cause the suction catheter to be linear or substantially linear when placed over the suction catheter. The cannula may be withdrawn to progressively expose the curved or nonlinear portion of the aspiration catheter, thereby enabling the catheter to assume different degrees of curvature. In this case, the catheter may be configured with a variable curved tip for navigation and/or clot finding purposes. In some embodiments, the aspiration catheter having a curved or nonlinear portion may be configured to rotate about its longitudinal axis to direct the distal opening of the aspiration catheter toward different sides of the vessel, e.g., to facilitate capturing different portions of a larger clot.

Further details of a thrombectomy system, including aspiration catheters having larger diameter tips and a rotational axis, are described below with reference to the drawings.

I. System and method for controlling a system

The systems and devices described herein may be configured to remove obstructive material from the vasculature, including, for example, the pulmonary artery. The systems and devices described herein may include a catheter assembly and a shaft assembly, as depicted in fig. 2A, 2B, and 3. Fig. 2A is a schematic block diagram of a catheter assembly 100 of a thrombectomy system or aspiration catheter system. The catheter assembly 100 may include a distal end that may be disposed in a body lumen or lumen (e.g., a pulmonary artery). In some embodiments, the catheter assembly 100 may include a catheter 114 (e.g., an aspiration catheter) and a sleeve or sheath 118. The catheter 114 and the sleeve 118 may be coupled at a proximal end to a handle assembly 160 that includes one or more catheter adjustment mechanisms 162 (also referred to as first adjustment mechanisms) configured to translate the sleeve 118 relative to the catheter 114 (or vice versa). Catheter adjustment mechanism 162 may be configured to translate one or more elements of catheter assembly 100, such as catheter 114, cannula 118, and/or a guidewire (not shown). In some embodiments, catheter adjustment mechanism 162 may be configured to advance and retract catheter assembly 100 within one or more vascular lumens. In some embodiments, the catheter adjustment mechanism 162 may include components (e.g., rollers, knobs, and/or slides) configured to translate the sleeve 118 relative to the catheter 114 such that the distal end of the catheter 114 may be exposed distally of the sleeve 118 and configured to expand within a body lumen. In some embodiments, the catheter adjustment mechanism 162 may be configured to gradually withdraw the cannula 118, e.g., to achieve variable curvature and/or expansion of the distal end of the catheter 114. In some embodiments, the catheter adjustment mechanism 162 may be configured to rotate the catheter 114 and/or the sleeve 118, e.g., for manipulating and/or finding a clot (e.g., sweeping a body vessel to orient the distal opening of the catheter 114 in the direction of the clot or a portion thereof). In some embodiments, the catheter adjustment mechanism 162 may include one or more actuators (e.g., rollers, knobs, and/or slides) that may be configured to manipulate the distal portion of the catheter 114 (e.g., by retracting the cannula 118 to adjust the curvature of the catheter 114 and/or to rotate the catheter 114). This may be used to guide the curved end of the catheter 114 along the length and/or circumference of a large diameter vessel, as described in more detail with respect to fig. 14C and 15A-15E.

In some embodiments, the distal end of the catheter 114 (e.g., the expandable tip 219) may have a larger diameter than other portions of the catheter 114. For example, the distal end of the catheter 114 may be expandable and may transition from a first diameter (e.g., a first configuration, a retracted configuration) to a second diameter (e.g., a second configuration, an expanded configuration) within the cannula 118 once extending out of the cannula 118 (e.g., translated relative to the cannula 118). The expandable tip may use a more easily navigated catheter to facilitate uptake of large clot payloads. In some embodiments, the distal end of the catheter 114 may have a funnel-shaped structure, such as described in further detail in fig. 4-6. In some embodiments, the distal end of the catheter 114 may have an atraumatic tip in an expanded configuration. For example, the distal end of the catheter 114 may have a rounded or cylindrical tip, or have a soft structure (e.g., a pliable structure) designed to reduce the risk of injury when the catheter 114 is positioned within a body lumen of a patient.

In some embodiments, the handle assembly 160 may be coupled to or include a connector 164 for coupling the handle assembly 160 to the shaft assembly 102, as described in more detail with respect to fig. 2B. In some embodiments, the connector 164 may be in line with the longitudinal axis of the catheter assembly 100, and in some embodiments, the connector 164 may be angled away from the longitudinal axis of the catheter assembly 100. In some embodiments, the handle assembly 160 may be coupled to or include a vacuum port 120 configured to be coupled to a vacuum source VS. The vacuum source VS may be configured to create a negative pressure (e.g., aspiration) within the lumen of the catheter 114. For example, thrombus from the thrombus site TS may be drawn into the distal opening of the catheter 114 by suction created by the vacuum source VS. The handle assembly 160 may be coupled to a proximal end of the suction catheter 114.

As described above, in some embodiments, the catheter 114 may be a suction catheter. For larger aspiration catheters, it may be important to monitor and limit blood loss through catheter 114, for example, due to aspiration of blood and/or clots from within a body lumen (e.g., a vessel). For example, it may be important to limit blood loss to, for example, 250ml or less. In some embodiments, the handle assembly 160 may optionally include a vacuum interrupter or valve 163 configured to shut off or reduce vacuum or suction through the conduit 114. For example, the vacuum interrupter 163 may be configured to close to turn off the vacuum such that blood and/or clot is no longer drawn through the catheter 114. In some embodiments, the vacuum interrupter 163 may be manually controlled, including for example a switch, button, or other actuator configured to be manually controlled by a user. The user may actuate a switch, button, etc. to turn on the vacuum and may release the vacuum to reduce or turn off the vacuum within the conduit 114. The user may also use switches, buttons, etc. to create pulsed suction and/or meter flow. In some embodiments, the vacuum interrupter 163 may be electronically and/or mechanically controlled such that, for example, the vacuum interrupter 163 may automatically shut off (or reduce) the vacuum within the conduit 114 when the blood flow rate is above a predetermined threshold. In some embodiments, the vacuum interrupter 163 may be configured to turn off and/or shut off the vacuum, while in other embodiments, the vacuum interrupter 163 may be configured to adjust the amount of vacuum pressure (e.g., between one or more values).

In some embodiments, the vacuum interrupter 163 may be configured to control activation of the drive system 132 of the shaft assembly 102, such as control activation of the shaft 112 (e.g., control when rotation of the shaft 112 is activated). For example, the vacuum interrupter 163 may be configured to interface with a controller of the shaft assembly 102 and indicate to the controller (e.g., by sending a signal to the controller) when the vacuum or suction has been activated. In response to receiving the indication from the vacuum interrupter 163, the controller may be configured to cause the drive system 132 to activate rotation of the shaft 112. Alternatively, the vacuum interrupter 163 may be configured to directly control activation of the drive system 132 of the shaft assembly 102, such as by coupling a power source to the drive system 132 (e.g., a motor of the drive system 132). For example, the vacuum interrupter 163 may be configured to (1) activate the vacuum pressure in response to a first actuation or actuation to a first position, and (2) activate the drive system 132 in response to a second actuation or actuation to a second position (e.g., by coupling the drive system 132 to a power source). Where the vacuum interrupter 163 is a button, the button may be configured to (1) activate the vacuum pressure in response to being pressed a first amount, and (2) activate the drive system 132 in response to being pressed a second amount that is greater than the first amount. Further details of such an embodiment are described with reference to fig. 19.

In some embodiments, the handle assembly 160 may optionally include a separate actuating element 161 configured to be releasably coupled to the drive unit 140 of the shaft assembly 102, as described in more detail with respect to fig. 2B. The actuation element 161 may be configured to reversibly couple and decouple the power source to the drive unit 140, for example, to control activation of movement of the shaft 112 and/or stylet 116. In some embodiments, the handle assembly 160 may include a set of activation elements for independently rotating and translating the aspiration catheter 114. In some embodiments, the vacuum pressure may be applied when an operator engages an activation element (e.g., the vacuum interrupter 163 or a separate activation element 161) and stops when the activation element has been released.

The sleeve 118 and catheter 114 may be configured for navigation through the vasculature of a patient to a target area within a body lumen of the patient, such as the pulmonary artery of the patient. The sleeve 118 and catheter 114 may be arranged concentrically, wherein the interior lumen of the catheter 114 may be advanced along a guidewire (depicted). In use, the guidewire may be positioned within a target vessel within the patient's vasculature, and the sleeve 118 and catheter 114 may be advanced over the guidewire and into the target vessel.

In some embodiments, the handle assembly 160 may optionally include a port 122, including, for example, a fluid port. The fluid ports may be used to flush the aspiration lumen and/or deliver one or more substances (e.g., one or more agents for breaking up clots or thrombi) into the body cavity. In some embodiments, the port 122 may include a port for receiving a guidewire such that the catheter 114 and the cannula 118 may be advanced along the guidewire to a target location within the body lumen.

Fig. 2B is a schematic block diagram of the shaft assembly 102 of the thrombectomy system, including a shaft 112 and an optional stylet 116 disposed within the lumen of the shaft 112. The proximal ends of the shaft 112 and stylet 116 can be coupled to a drive unit 140 that includes a drive system 132 and one or more optional second adjustment mechanisms 134. The drive system 132 may be configured to rotate the shaft 112 and/or stylet 116 such that when negative pressure is applied to the lumen of the catheter 114, the distal end of the flexible shaft may be rotated axially and/or about the longitudinal axis of the catheter 114, for example, to remodel and/or destroy a thrombus and cause the thrombus to be inhaled proximally within the lumen of the catheter 114. The shaft assembly 102 may include a shaft adjustment mechanism 134 (also referred to as a second adjustment mechanism) configured to translate the shaft 112 and/or the stylet 116, for example, for fine tuning the position of the shaft 112 and/or the stylet 116 relative to the catheter 114.

The drive system 132 may be configured to axially rotate the shaft 112 and/or stylet 116, for example, to produce axial and orbital movement of the shaft 112, as described in more detail herein. In some embodiments, the drive system 132 may include a single motor that drives the movement of the shaft 112 and/or stylet 116. In such embodiments, one or more gears having different gear ratios may be used to drive the shaft 112 and/or stylet 116 at different speeds. In some embodiments, the drive system 132 may include two drive motors configured to independently drive movement (e.g., translation and/or rotation) of the shaft 112 and/or stylet 116. In some embodiments, the shaft assembly 102 may not include the stylet 116, and in such cases, the drive system 132 may include a single motor configured to rotate the shaft 112.

In some embodiments, drive unit 140 may optionally be coupled to one or more ports 152. For example, the port 152 of the shaft assembly 102 may be used to receive a guidewire, e.g., such that the catheter assembly 100 and the shaft assembly 102 may be advanced along the guidewire.

In some embodiments, the catheter assembly 100 and the shaft assembly 102 can be releasably coupled to one another. For example, the drive unit 140 may be coupled to a port or connector (e.g., to the connector 164) of the handle assembly 160. In this configuration, when the drive unit 140 is coupled to a port or connector, the shaft 112 may be disposed within the lumen of the catheter 114.

In use, the catheter 114 may first be placed at a target location within a body lumen, and the shaft 112 may be inserted through an internal lumen (e.g., aspiration lumen) of the catheter 114 until the distal end of the shaft 112 is at a preset position relative to the distal end of the catheter 114. In some embodiments, one or more adjustment mechanisms (e.g., adjustment mechanisms 134, 162) may be actuated to adjust the relative position of shaft 112 and/or catheter 114 (or other components of the system, such as stylet 116 and/or cannula 118). Alternatively, in some embodiments, the shaft 112 may have a preset length that is in a preset position (or within a range of preset positions) relative to the distal end of the catheter 114 after being inserted into the lumen of the catheter 114 and advanced to the point where the drive unit 140 of the shaft assembly 102 is coupled to the handle assembly 160 of the catheter assembly 100.

In some embodiments, one or more of the catheter 114, the shaft 112, and/or the stylet 116 can be similar in structure and/or function to those described in international application serial No. PCT/US2019/026737 and U.S. application serial No. 63/155,191 (which applications are incorporated by reference above). As described in greater detail herein, the shaft 112 may be configured to axially and orbitally rotate within the lumen of the catheter 114 when the shaft assembly 102 is coupled to the catheter assembly 100.

In some embodiments, the catheter 114 may be used as a suction catheter. A negative pressure may be applied to the lumen of the catheter 114 (e.g., via vacuum source VS), and the shaft 112 and optional stylet 116 may be rotated axially and orbitally within the catheter 114 to remodel and remove thrombus from the body lumen. In some embodiments, the catheter assembly 100 and the shaft assembly 102 may include one or more seals and/or valves (e.g., mechanical seals or valves) configured to facilitate sealing of different portions of the system for maintaining negative pressure within the lumen of the catheter 114 and/or preventing fluid leakage.

In some embodiments, one or more of the handle assembly 160 and the drive unit 140 may include an on-board power source (e.g., a battery) for driving movement (e.g., translation, rotation) of the cannula 118, catheter 114, shaft 112, and/or stylet 116. In some embodiments, the handle assembly 160 and/or the drive unit 140 may be coupled to an external power source for driving movement of the cannula 118, the catheter 114, the shaft 112, and/or the stylet 116. In some embodiments, the handle assembly 160 may not include or be coupled to a power source, and movement of the catheter 114, the cannula 118, the shaft 112, and/or the stylet 116 may be manually actuated by a user, for example, using one or more adjustment mechanisms 162 and/or 134.

An optional stylet 116 can be configured to rotate axially within the shaft lumen to impart orbital motion on the shaft 112. The stylet 116 may be flexible while also having sufficient torsional stiffness to permit axial rotation. In some embodiments, the stylet 116 can include features such as a predetermined torsional stiffness (e.g., high enough to withstand its rotational speed, e.g., about 30,000rpm or less), a minimum bend radius (e.g., about 4 inches or about 10cm bend radius or less), and sufficient flexibility (e.g., high enough to enable navigation through fragile and tortuous vasculature). For example, the stylet 116 can be flexible enough to translate through the shaft lumen to a predetermined portion of the shaft or target site, as well as a tortuous path (e.g., through the vasculature). In some embodiments, the stylet may be composed of, for example, nitinol, which may be heat set to form a predetermined shape. Stylet 116 can be configured to have a non-linear shape such that when stylet 116 is inserted into shaft 112, stylet 16 can cause shaft 112 to assume a non-linear shape. Thus, stylet 116 may have a strength that is greater than shaft 112.

In some embodiments, the shaft 112 may be configured with a bent, curved, or other non-linear portion. The shaft 112 may be preformed to have its nonlinear shape. For example, the shaft 112 may have a curved portion near its distal end such that the distal end of the shaft 112 is angled or curved away from the longitudinal axis of the linear proximal portion of the shaft 112. Further details of such curved or nonlinear axes are described with reference to fig. 5-6. For non-linear axes, a stylet (e.g., stylet 116) may not be required. Accordingly, the thrombectomy system described herein may include an aspiration catheter (e.g., catheter 114) having a rotational axis (e.g., shaft 112) without a stylet (e.g., stylet 116). In such embodiments, the non-linear axis of the shaft may impart or cause orbital or off-axis motion of the shaft.

Fig. 3 is a schematic block diagram illustrating a more detailed view of the distal end of catheter assembly 210 and shaft assembly 211 of the embolectomy system. Catheter assembly 210 may include a catheter 214 defining a catheter lumen 215 and a cannula 218 defining a cannula lumen. Catheter 214 may be slidably disposed within the cannula lumen. The shaft assembly 211 can include a shaft 212 slidably disposed within a catheter lumen 215. Catheter assembly 210 and shaft assembly 211 may include components similar in structure and/or function to catheter assembly 100 and shaft assembly 102, respectively, as described above with reference to fig. 2A and 2B. In some embodiments, catheter 214, cannula 218, shaft 212, stylet 216, and/or drive system 232 may be similar in structure and/or function to catheter 114, cannula 118, shaft 112, stylet 116, and/or drive system 132, respectively, described with respect to fig. 2A and 2B. In some embodiments, the shaft 212 can define a shaft lumen 213. Optionally, a stylet 216 can be disposed within the shaft lumen 213. In some embodiments, stylet 216 can be a second shaft (e.g., an inner shaft) and shaft 212 can be a first shaft. In some embodiments, stylet 216 can be movable (e.g., translatable) relative to shaft 212. In some embodiments, stylet 216 and shaft 212 can be movable (e.g., translatable) relative to catheter 214.

In some embodiments, the distal end of catheter 214 may include an expandable tip 219 that expands once extended out of the lumen of sleeve 218. When disposed within the cannula 218, the expandable end 219 may be constrained to a lower profile configuration (e.g., a retracted configuration), but when the cannula 218 is retracted relative to the catheter 214 (or the catheter 214 is advanced relative to the cannula 218), the expandable end 219 may transition to its expanded configuration. Expandable tip 219 can have an atraumatic tip. In some embodiments, the expandable end 219 includes a frame or support structure formed, for example, from a metallic material. In some embodiments, the outer and/or inner surfaces of the expandable end 219 may include a membrane or flexible cover, for example, covering one or more portions of the inner frame of the expandable end 219. For example, the membrane may have a flexible structure (e.g., a pliable structure) designed to reduce the risk of injury when the catheter 214 is positioned within a body lumen of a patient. Further, the membrane or flexible cover may be configured to change shape (e.g., between a retracted configuration and an expanded configuration) with the expandable end 219 of the catheter 214.

In some embodiments, the drive system 232 (e.g., similar in function and/or structure to the drive system 132) may be mechanically and/or electrically coupled to the shaft 212 and optionally to the stylet 216. The drive system 232 may be configured to drive (e.g., axially rotate) one or more of the shaft 212 and the stylet 216. In some embodiments, the drive system 232 may include a first drive mechanism coupled to the shaft 212 and a second drive mechanism coupled to the stylet 216, and each drive mechanism may be configured to independently rotate the shaft 212 and the stylet 216, respectively. In some embodiments, a single drive mechanism may be used for both the drive shaft 212 and the stylet 216, but different coupling mechanisms (e.g., gears, cams, etc.) may be used to cause different rotational speeds and/or directions in the shaft 212 and the stylet 216 and/or cannula 218.

In some embodiments, the shaft 212 may rotate in a first direction (e.g., clockwise, counterclockwise) at a first speed (e.g., revolutions Per Minute (RPM)), while the stylet 216 may rotate in a second direction or in the same direction at a second speed. The shaft 212 may be shaped as further described with reference to fig. 5-7B and 14C-14D. In some embodiments, the shaft 212 may have a predetermined nonlinear shape, such as a bend or curve, for example. Rotation of the shaft 212 may cause a distal nonlinear portion (e.g., a bend or curved portion) of the shaft 212 to move along a track about a longitudinal axis of a proximal linear portion of the shaft 212. Alternatively, the shaft 212 may be generally linear, but may take on a non-linear shape when the shaped stylet 216 (e.g., the stylet 216 with a bend or curve) is disposed within the lumen of the shaft 212. In the latter case, stylet 216 can be configured to impart a predetermined shape on shaft 212 based on the relative positioning of shaft 212 and stylet 216. For example, because the stylet 216 imparts a shape to the shaft 212, rotation of the stylet 216 may cause orbital motion in the shaft 212. Aspiration and removal of thrombus from within a vascular lumen (e.g., a patient's vessel) and lumen 215 may depend at least on the speed and direction of both the orbital and rotational movement of shaft 212. In some embodiments, the shaft 212 may rotate at a speed of less than about 30,000rpm, or less than about 20,000rpm, or less than about 10,000 rpm. In some embodiments, stylet 216 can be rotated at a speed of less than about 30,000rpm, or less than about 20,000rpm, or less than about 10,000 rpm. In embodiments having a stylet 216, the shaft 212 can rotate at a speed greater than the stylet 216. For example, the shaft 212 may rotate at a speed of about 10,000RPM to about 20,000RPM, while the stylet 216 may rotate at a speed of about 10,000RPM or less. In some embodiments, the shaft 212 may rotate at twice the speed of the stylet 216 or higher. In use, the distal end of the shaft 212 having a non-linear shape may be configured to rotate within the expandable tip 219 as the expandable tip 219 expands to engage and remodel the portion of thrombus captured within the expandable tip 219 (e.g., sucked or sucked into the expandable tip 219).

The movement of the shaft 212 is a combination of induced orbital movement and axial rotation. In some embodiments, the orbiting characteristics of the shaft 212 may depend on the shape of the stylet 216 and/or the positioning of the stylet 216 relative to the shaft 212, as described in more detail in U.S. application serial No. 63/155,191, which is incorporated by reference above.

In some embodiments, catheter assembly 210 may be advanced into the vessel lumen toward the thrombus site (not shown). For example, the distal end of the catheter 214 may be disposed proximate to a thrombus site. Once positioned, the cannula 218 may be withdrawn and the expandable end 219 may be expanded within the vessel lumen (or the catheter 214 may be pushed out of the cannula 218 and the expandable end 219 may be expanded within the vessel lumen). Expandable tip 219 may be configured to transition from its compressed configuration within cannula 218 to its expanded configuration outside cannula 218. The diameter of lumen 215 at expandable end 219 may increase as expandable end 219 transitions from the compressed configuration to the expanded configuration. This increased diameter of lumen 215 may facilitate capture and removal of thrombus, as described further below.

As shown in fig. 3, the distal end of the shaft 212 and/or stylet 216 can be positioned proximal to the distal end of the catheter 214, such as within the expandable tip 219. As described above, catheter 214 in its expanded state (e.g., with expandable tip 219 in an expanded configuration) may have a larger diameter lumen at its distal end, which allows thrombus to be aspirated into catheter lumen 215 prior to mechanical interaction with one or more of shaft 212 and stylet 216. The larger diameter lumen of the expandable end 219 may allow thrombus to be aspirated into the lumen without or with reduced compression or compression, which may, for example, allow the thrombus to be more easily destroyed or remodelled by the shaft 212 and/or stylet 216 as the shaft 212 and/or stylet 216 rotate within the expandable end 219. For example, a two-fold increase in tip diameter (e.g., from 12F to 24F) corresponds to an approximately four-fold increase in clot engaging force when vacuum pressure is applied. The expandable tip may also increase the depth of ingestion and promote acceleration of the clot toward the shaft 212 disposed within the catheter lumen such that the shaft 212 need not extend distally of the catheter and be exposed within the body lumen.

Additionally or alternatively, one or more of the shaft 212 and stylet 216 can be aligned with respect to the distal end of the catheter 214 or advanced distally of the distal end of the catheter 214. Additionally or alternatively, stylet 216 can be aligned with the distal end of catheter 214, or disposed proximal or distal to the distal end of shaft 212. In operation, the distal end of the shaft 212 and/or stylet 216 can be disposed distally of the catheter 214 while navigating the catheter 214 and/or shaft 212 to a thrombus site. For thrombectomy, the distal end of the shaft 212 may be positioned proximal to the distal end of the catheter 214. In some embodiments, the distal end of the stylet 216 can be positioned proximal to the distal end of the shaft 212, while in other embodiments, the distal end of the stylet 216 can be positioned at the distal end of the shaft 212 and/or distal to the distal end of the shaft 212 but proximal to the distal end of the catheter 214. The shaft 212 and/or stylet 216 positioned within the lumen 215 of the catheter 214 can then be rotated, for example, to cause rotation and orbital movement of the shaft 212 while applying negative pressure (e.g., via the vacuum source VS) to remodel, destroy, and/or aspirate thrombus proximally within the lumen 215. For example, the distal end of the shaft 212 and/or stylet 216 can be configured to rotate within about 1cm of the proximal end of the expandable tip 219 when the expandable tip 219 is in the expanded configuration to engage and remodel portions of a thrombus disposed within the expandable tip 219.

The shaft 212 may be similar in structure and/or function to the shafts described in International application Ser. No. PCT/US2019/026737 and U.S. application Ser. No. 63/155,191, which are incorporated by reference above. For example, the shaft 212 may be formed of a material having different diameters,A plurality of segments of a winding combination and/or a braiding combination. In some embodiments, shaft 212 may be formed from one or more layers of coils, wires, or braids. For example, shaft 212 may be a double-layered shaft in which each layer is constructed of coiled flat or round wire. In some implementations, the wires of each layer may be wound in different directions. Alternatively, the shaft may be formed from a solid tube with or without slots or cuts. The shaft 212 may have different sections or portions that have different torsional strength and/or flexibility. For example, the shaft 212 may have a larger dimension at the proximal end to obtain a greater torsional strength (e.g., an outer diameter of about 0.022 inches to about 0.065 inches, an inner diameter of about 0.012 inches to about 0.046 inches, and a bending stiffness of about 50 Nmm) ² To about 5000Nmm ² ) And has a smaller dimension at or near the distal end (e.g., an outer diameter of about 0.020 inches to about 0.055 inches, an inner diameter of about 0.012 inches to about 0.046 inches, and a bending stiffness of about 5 Nmm) ² To about 500Nmm ² ). In some embodiments, the shaft 212 may have at least three sections, each section having a different diameter and/or torsional strength, wherein the torsional strength is reduced in the more distal sections. For example, the shaft 212 may have a first section closest to the proximal end, a second section closest to the distal end, the first section having a first degree of stiffness, the second section having a second degree of stiffness less than the first degree of stiffness, and a third section between the first and second degrees of stiffness. In some embodiments, the shaft 212 may have a stiffness that gradually decreases from the proximal end to the distal end, e.g., due to a decrease in diameter, a change in pitch and/or size of the coiled wire, etc. In some embodiments, the shaft 212 may have a bend, curve, or other non-linear portion such that the distal end of the shaft 212 is angled relative to the longitudinal axis of the shaft 212 or toward the wall of the catheter 214. In this case, rotation of the shaft 212 may cause the distal end of the shaft 212 to move along the track.

In some embodiments, the optional stylet 216 can be, for example, a second shaft disposed within the shaft 212. The stylet 216 can be similar in structure and/or function to the shaft described in U.S. application Ser. No. 63/155,191 (which is incorporated by reference above). In some embodiments, stylet 216 can include an internal lumen, for example, for receiving a guidewire. In some embodiments, stylet 216 can be a solid flexible rod. In some embodiments, stylet 216 may be formed from one or more layers of loops, wires, or braids. For example, stylet 212 may be a double-layered shaft, wherein each layer is constructed of a flat or round coiled wire. In some implementations, the wires of each layer may be wound in different directions. In some embodiments, stylet 216 may be a hypotube with or without a slot or incision. In some embodiments, stylet 216 can include multiple sections, each section having a different size and/or stiffness. As described above, stylet 216 can include a distal portion having a shaped geometry. For example, stylet 216 can include a bend near the distal end of stylet 216, which causes the distal end of stylet 216 to be directed toward the sidewall or inner surface of catheter 214. In some embodiments, stylet 216 can be shaped as multiple bends or a continuous complex shape, such as a spiral.

The optional stylet 216 (or a portion of the stylet 216) can have a bending stiffness that is greater than a bending stiffness of at least a portion of the shaft 212 such that the shaped distal end of the stylet 216 can impart a shape to the shaft 212 when disposed within the lumen of the shaft 212, the shaft 212 and stylet 216 being configured to rotate such that the distal end of the shaft 212 can rotate axially about the longitudinal axis of the shaft 212 and orbitally about the longitudinal axis of the catheter 114.

In some embodiments, the flexural rigidity may be about 2Nmm ² To about 800Nmm ² . When the stylet 216 is inserted into the shaft 212, the stylet 216 can impart its shape to the shaft 212 by having greater rigidity. Thus, when stylet 216 is disposed within shaft 212, shaft 212 and stylet 216 assume the geometry of stylet 216. Thus, by designing stylet 216 to have a particular geometry at various portions along the length of stylet 216, stylet 216 can cause shaft 212 to have various shapes and to appear when shaft 212 and/or stylet 216 are rotatedA specific movement. In some embodiments, stylet 216 can be used to control the orbital motion of shaft 212, such as by customizing stylet 216 to have a particular shape, by positioning stylet 216 at different positions relative to shaft 212, and/or by rotating stylet 216 at different rotational speeds. For example, when the stylet 216 is disposed within the shaft 212 and rotates at a predetermined speed, the stylet 216 can cause the shaft 212 to orbit at or based on the predetermined speed. As another example, as the shaft 212 moves within the catheter lumen 215, the stylet 216 can cause the shaft 212 to have the same or substantially similar shape by having a particular shape (e.g., a bend) at its distal end.

Fig. 4 is a schematic block diagram providing a detailed view of the distal end of the catheter assembly 310 and the thrombectomy system. Catheter assembly 310 may include a catheter 314 defining a catheter lumen 315. Catheter assembly 310 may include components similar in structure and/or function to catheter assemblies 100, 210, respectively, as described above with reference to fig. 2A and 3. In some embodiments, the conduit 314, vacuum interrupter 363, and/or vacuum source VS may be similar to the conduit 114, 214, vacuum interrupter 163, and/or vacuum source VS, respectively, of fig. 2A, and certain details of these components are not repeated for the sake of brevity. In some embodiments, catheter 314 may define a catheter lumen 315. A shaft and/or stylet (not shown) may be disposable within the catheter lumen 315, as described above with reference to catheter 214 and shaft 212 in fig. 3. For example, the flexible shaft (e.g., shaft 112, 212) may have a distal end that is disposable within the expandable tip 319 of the aspiration catheter 314. Expandable tip 319 can include a frame (e.g., a metal frame) and, optionally, a flexible cover 320 covering the frame.

In some embodiments, catheter 314 may include a linear section 317, a curved section 318, and an expandable distal tip 319. The linear section 317 may comprise an elongate body extending from a proximal end of the catheter 314 and may be substantially linear (e.g., without any preformed bends, curves, or other non-linear shapes). The linear section 317 may be flexible enough to conform to the shape of the vessel (e.g., bend, kink) as the catheter 314 is passed through the vasculature.

The curved distal portion of the catheter 314 may facilitate improved positioning of the distal end of the catheter 314 relative to a thrombus site and/or body cavity. The curved section 318 may be coupled to a distal end of the linear section 317 and a proximal end of the expandable tip 319. Lumen 315 may be defined continuously through each of linear section 317, curved section 318, and expandable end 319. The curved section 318 may include a preset bend or other non-linear shape such that the curved section 318 deflects the distal end (e.g., the expandable tip 319) of the catheter 314 from the longitudinal axis of the linear section 317 of the catheter 314. In some embodiments, the curved section 318 may be formed of or include a memory setting metal or metal alloy. When positioned within a cannula (e.g., cannula 218), the curved section 318 may be constrained to a more straight or linear shape, but when extending from the cannula (e.g., extending distally from the cannula), the curved section 318 may be configured to transition from its constrained linear configuration to its preset curved configuration. The curved section 318 may be configured to set the expandable end 319 of the catheter at a predetermined angle relative to the longitudinal axis of the linear section 317. In some embodiments, the curved section 318 may set the expandable end 319 at an angle of about 10 degrees to about 90 degrees (including all subranges and values therebetween) relative to the linear section 317. In some embodiments, depending on the distance the curved section 318 extends out of the cannula, the curved section 318 may be configured to set the expandable end 319 at different angles relative to the longitudinal axis of the linear section 317. As such, the bending section 318, along with the cannula, may be configured to provide variable bending or curving of the distal end of the catheter 314. Alternatively, in some embodiments, the bending section 318 may be coupled to a pull wire or other element to adjust its degree of bending or buckling. The curved section 318 may serve as a base or collar for the expandable end 319. The curved section 318 may have a hoop strength sufficient to prevent collapse under negative pressure (e.g., generated by a vacuum source) and a strength sufficient to prevent damage to a shaft (e.g., shaft 212) as the shaft rotates within the catheter lumen 315.

The curved section 318 extending at least partially from the distal end of the cannula may be configured to have a radius of curvature of about 10mm to about 40 mm. The linear section or elongate body 317 may be coupled to an actuator configured to selectively control the extent of extension of the bending section 318 from the distal end of the cannula, for example, to change the memory setting the degree of bending of the bending section 318 and the position of the expandable tip 319 within a vessel (e.g., a body vessel). With the curved section 318 extended, the linear section 317 can be rotated within the cannula lumen to change the position of the expandable end 319 within the vessel. In some embodiments, the cannula may also have a curved section that cooperates with the curved section 318 of the catheter 314 to provide additional control over the positioning of the expandable end 319. For example, the linear section 316 may be configured to rotate within the cannula lumen to change the relative orientation of the curved section 318 with respect to the curved section of the cannula (e.g., change the direction of curvature of the curved section 318 with respect to the direction of curvature of the curved section of the cannula) such that each curved section may curve in the same or different directions to respectively enhance or reduce the overall radius of curvature of the aspiration catheter 314. As such, in some embodiments, the interaction between the curved section 318 of the catheter 314 and the curved section of the cannula may allow the distal portion of the catheter (e.g., the expandable end 319 of the catheter) to be parallel and/or aligned with, or angled relative to, the proximal portion of the catheter (e.g., the linear section 317). Alternatively, in some embodiments, the catheter 314 may not include a curved section, but may be used with a cannula having a curved section that controls angulation or bending of the distal end of the catheter 314.

In some embodiments, one or more apertures 321 may be provided on conduit 314. The aperture 319 may be disposed near or on a proximal portion of the expandable tip 319, such as on the curved section 318 or at a proximal end of the expandable tip 319. For example, the expandable end 319 may be formed from a metal frame including a plurality of holes. The metal frame may be covered by a film along a majority of its length, but one or more rows of metal frames comprising a set of holes may be uncovered such that those holes serve as holes 321. Alternatively or in addition, the proximal curved section 318 of the expandable end 319 and/or the proximal portion of the expandable end 319 may define a set of holes 321 spaced around the circumference of the respective curved section 318 and expandable end 319. The aperture 319 may be configured to increase the fluid available for mixing with thrombus to improve the flow of thrombus proximally through the lumen 315 from the relatively larger inner diameter of the expandable end 319 into the relatively smaller inner diameter of the lumen 315 of the linear section 317. In particular, when a large thrombus is trapped within the expandable end 319, the thrombus may stagnate and reduce or shut off blood flow through the lumen 315. An expandable tip 319 having one or more holes 321 disposed within the curved section 318 and/or having a partially ingested thrombus may allow blood to still travel into the lumen 315, thereby mixing with the thrombus and promoting proximal movement of the thrombus. In some embodiments, each aperture in the set of apertures 321 may have a diameter of about 0.3mm to about 1mm (including all subranges and values therebetween).

Expandable tip 319 can be configured to draw a clot or thrombus from a vascular lumen into catheter 314 such that a shaft (e.g., shaft 212) can engage and remodel the clot to remove the clot from the vascular lumen. Expandable tip 319 can define a larger diameter portion of lumen 315 (e.g., a portion of lumen 315 having a larger diameter than a more proximal portion of lumen 315, such as, for example, a portion of lumen 315 defined by linear section 317). The larger diameter portion of lumen 315 may enable thrombus to be drawn into catheter 314 without significant compression or compression, which may, for example, facilitate easier disruption or remodeling of the thrombus by the shaft assembly. In some embodiments, the expandable end 319 coupled to the curved section 318 can transition between an unexpanded or retracted configuration (e.g., when disposed within a cannula) and an expanded configuration (e.g., when disposed outside of the cannula).

In some embodiments, the expandable tip 319 in the expanded configuration may have a generally funnel-shaped profile with a diameter that gradually increases from the proximal end of the expandable tip 319 to the distal end of the expandable tip 319. In some embodiments, the expandable end 319 may include a first section P1, a second section P2, and a third section P3, where each section P1, P2, P3 has different structural and/or material properties. For example, each section P1-P3 of the expandable end 319 may have a different cutting pattern. Each section P1-P3 may have a different strength such that the more distal section has a greater strength than the more proximal section. The cutting pattern at the distal end of the expandable tip 319 (e.g., distal end of section P3) may be selected to be atraumatic design while withstanding shaft rotation, negative aspiration, and luminal collapse. While three sections P1, P2, P3 are described, it should be understood that the expandable tip as described in this disclosure may include any number of sections having different structural and/or material characteristics.

In some embodiments, the sections P1, P2, P3 may comprise a metal frame, wherein each section P1, P2, P3 of the metal frame has a different mechanical structure. For example, section P1 of the metal frame may include holes or openings having a first set of geometric parameters (e.g., size, shape, orientation, etc.), section P2 of the metal frame may include holes or openings having a second set of geometric parameters, and section P3 of the metal frame may include holes or openings having a third set of geometric parameters. Each of the first set of geometric parameters, the second set of geometric parameters, and the third set of geometric parameters may be different. In one embodiment, the aperture of section P1 may have a first longitudinal length, the aperture of section P2 may have a second longitudinal length greater than the first longitudinal length, and the aperture of section P3 may have a third longitudinal length greater than the first and second longitudinal lengths. In the same or other embodiments, the apertures of sections P1, P2, and P3 may have different widths, shapes, etc.

In some embodiments, as described in greater detail with respect to fig. 14A-14D, the expandable end 319 can be formed from a plurality of holes having different patterns (e.g., cutting pattern, laser cutting pattern) along the longitudinal axis of the end 319. For example, each section P1, P2, and P3 may have a different hole pattern configured to maintain its expanded shape under the negative suction applied through lumen 315.

As depicted in fig. 4, the diameter of lumen 315 within expandable tip 319 may increase toward the distal end of catheter 314 such that, for example, the lumen diameter of third section P3 is greater than the lumen diameter of second section P2, and the lumen diameter of second section P2 is greater than the lumen diameter of first section P1. In some embodiments, the transition in lumen diameter from the first section P1 to the second section P2 to the third section P3 may be gradual. Additionally or alternatively, the expandable end 319 in the expanded configuration may have one or more stepped sections, each of the plurality of stepped sections having a different diameter, wherein the more distal stepped section has a larger diameter than the more proximal stepped section. In some embodiments, the maximum diameter of the catheter lumen 315 at the expandable end 319 may be about 1.5 times to about 5 times the diameter of the catheter lumen 315 proximal of the expandable end 319 (e.g., linear section 317, curved section 318), including all subranges and values therebetween. The expandable end 319 in the expanded configuration may have a maximum diameter that is greater than a diameter of a cannula (e.g., cannula 218) used to constrain the expandable end 319 to a smaller diameter when delivering the expandable end 319 to a target site within a vessel lumen.

In some embodiments, the vacuum source VS may be fluidly and/or mechanically coupled to the vacuum interrupter 363 and the catheter lumen 315, and configured to apply negative pressure to destroy and/or aspirate a thrombus or clot proximally within the catheter lumen 315. For example, the proximal end of the catheter 314 may be coupled to a vacuum source VS configured to apply vacuum pressure (e.g., negative aspiration) within the lumen 315 of the catheter 314 to draw thrombus into the lumen 315. In some embodiments, the vacuum interrupter 363 may be configured to control the amount of vacuum pressure passing through the catheter lumen 315 and exiting the distal end of the catheter 314. In some embodiments, the vacuum interrupter 363 may be a valve and/or an activation element configured for manual control of continuous and/or discrete negative suction levels. For example, the vacuum interrupter 363 may be disposed within a handle assembly coupled to the proximal end of the catheter 314.

In operation, the expandable end 319 can be navigated to a target location within a vessel and expanded (e.g., positioned outside of a cannula). Vacuum pressure may be applied to lumen 315 (e.g., via vacuum source VS) to aspirate the clot from the vascular lumen. In some embodiments, the rotation shaft and/or stylet may be disposed within the lumen 315 with the distal end of the lumen disposed within the expandable tip 319, and rotation of the shaft and/or stylet may be used to remodel and/or destroy the clot such that the clot may be inhaled proximally by vacuum pressure.

In use, an expanding structure such as expandable end 319 may have a tendency to collapse closed in a flattened or flattened manner when a clot is drawn into expandable end 319 upon application of negative pressure. This will alter the operation of the device if the expandable end 319 collapses. As such, in some embodiments, the expandable end 319 can be configured to remain in an expanded configuration when negative pressure is applied to the catheter lumen 315, e.g., to avoid flattening or collapsing. This allows the expandable end 319 to remain open so that additional clot may be aspirated into the expandable end 319. The ability of the expandable end 319 to resist collapse in a flattened manner may be measured or estimated by determining the clamping strength of the expandable end 319. The clamping strength of the expandable end 319 (or any expandable structure) may be determined by measuring the force required to compress the expandable end 319 (or expandable structure) between two flat surfaces (e.g., plates) from its expanded diameter to its unexpanded diameter. As schematically illustrated in fig. 24, the clamping strength of the expandable end 2400 may be determined by using a pair of opposing plates 2450 to compress the expandable end 2400 having an expanded diameter 2410 down to an unexpanded diameter 2420. In some embodiments, the expandable end 319 in the expanded configuration may have a clamping strength of about 0.4lb to about 3lb (including all ranges and sub-values therebetween) when disposed within a vessel (e.g., at or near a patient's body temperature), e.g., such that the expandable end 319 in the expanded configuration is configured to withstand collapse due to a pressure gradient generated within the expandable end 319 as a result of a vacuum pressure acting on a clot within the expandable end 319.

After the clot has been removed, the expandable end 319 can be compressed back to its unexpanded configuration, for example, by retracting back into the cannula or advancing over the expandable end 319 through the cannula. Expandable tip 319 in the expanded configuration can be configured to retract into the cannula in response to a retraction force of about 0.5lbs to about 4.0lbs (including all ranges and sub-values therebetween).

As described above, the expandable end 319 can include a metal frame and a flexible cover 320 (e.g., a coating or film) disposed on (e.g., inside and/or outside of) the metal frame. In some embodiments, the distal end of the expandable tip (e.g., third section P3) may be atraumatic to reduce trauma to the tissue.

As described above, the expandable end 319 in some embodiments can have a metal frame defining a plurality of openings. For example, each aperture of the plurality of apertures has a thickness of at least about 0.5mm ² Is a part of the area of the substrate. The plurality of openings may increase in size from a proximal end (e.g., segment P1) to a distal end (e.g., segment P3) of the expandable tip 319. In some embodiments, the metal frame further comprises an atraumatic wave ring or structure at the distal end (e.g., P3) of the expandable tip 319. For example, the wavy ring may have fewer features (e.g., connection points, crowns) than the proximal row of holes. In some embodiments, the distal end (e.g., section P3) of the expandable tip 319 may have an atraumatic structure formed by one or more rows of holes having half or even less of the holes of the next most distal end row of holes. As described above, the expandable end 319 is configured to withstand collapse due to a pressure gradient created within the expandable end 319 as a result of vacuum pressure acting on a clot within the expandable end 319. To have such strength, the expandable end 319 may be designed with a particular hole pattern that provides greater strength at a more proximal section of the expandable end 319 (e.g., a section of the expandable end 319 proximal to where the clot joins the wall of the expandable end 319), wherein the pressure gradient may be greater. In particular, in some embodiments, the aperture of the plurality of apertures disposed at the proximal end of the expandable tip 319 (e.g., section P1) may have a length of about 2mm and the aperture of the plurality of apertures disposed at the distal end of the expandable tip 319 (e.g., section P3) may have a length of about 5mm when the expandable tip is in the retracted configuration. In some embodiments, the expandable end 319 is disposed at the expandable end when in the expanded configuration The apertures of the plurality of apertures at the proximal end (e.g., P1) of the end 319 may have a proximal angle as low as about-10 °, and the apertures of the plurality of apertures disposed at the distal end (e.g., P3) of the expandable tip 319 may have a proximal angle as high as about 40 °. The aperture is sized and angled to resist collapse of the expandable end 319 under vacuum while facilitating collapse of the expandable end 319 when the aspiration catheter is aspirated into the cannula. The angle of the aperture is described in more detail with respect to fig. 21D.

A flexible cover or coating 320 may be disposed on the outer and inner surfaces of one or more sections P1-P3 of the expandable end 319 and/or the curved section 318. For example, the coating may include an inner layer and an outer layer. In embodiments where the expandable end 319 includes a plurality of holes, the inner and outer layers of the coating 320 may be connected to one another at the plurality of holes. That is, the area of the openings enables the inner and outer layers of the coating 320 to be connected to each other at each opening. In this way, the expandable end 319 may form a solid funnel to facilitate thrombus engagement and removal. The flexible cover 320 may have a soft structure (e.g., a pliable structure) designed to reduce the risk of injury and enable the expandable end 319 to be captured within the cannula when the catheter 314 is positioned within a body lumen of a patient.

In some embodiments, the flexible cover 320 may be constructed of an elastic or inelastic material to accommodate expansion or collapse. The substantially inelastic material may include Polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), fluorinated Ethylene Propylene (FEP), polyethylene terephthalate (PET), or similar materials. The elastic material may include thermoplastics (e.g., polyurethane, pebax, polyolefin, nylon, etc.) and/or thermosets (e.g., silicone, bezels, polyurethane, etc.). In addition, a variety of materials may be used along the length or as layers to provide the desired mechanical properties. In one embodiment, a thin ePTFE coating may be used.

It should be appreciated that the flexible cover 320 enables the expandable end 319 to collapse when captured (e.g., withdrawn) within the cannula.

In some embodiments, the expandable end 319 can have a symmetrical shape that is symmetrically disposed about the longitudinal axis of the catheter 314. Alternatively, the expandable end 319 may have an asymmetric shape 319 (e.g., with one side extending more distally than the other side, or with one side extending more radially than the other side). In some embodiments, the expandable end 319 may have a predetermined curvature, such as curvature relative to the curved section 318 and/or the linear section 317.

Fig. 5 is a cross-sectional side view of a thrombectomy system 500 including a shaft 510, a catheter 512 having an expandable tip 513, and a cannula 514, according to an embodiment. Shaft 510, catheter 512, and cannula 514 may be similar in structure and/or function to other shafts, catheters, and cannulas described herein (e.g., shafts 112, 212, catheters 114, 214, 314, cannula 218, etc.). Catheter 512 may be slidable within the lumen of cannula 514, and shaft 510 may be slidable within the lumen of catheter 512. In some embodiments, the expandable tip 513 may expand after advancing from or being exposed to the outside of the distal end of the cannula 514. For example, the expandable tip 513 may have a funnel shape.

In some embodiments, the catheter 512 may have a curved distal section such that the expandable tip 513 may be angled relative to a longitudinal axis of the catheter 512, as further described with reference to fig. 14C-14D. The angulation of the expandable tip 513 may enable the expandable tip 513 to be moved to different lateral positions within a larger body lumen, for example, by rotating the catheter 512 about its longitudinal axis. In some embodiments, the curved distal end of the catheter 512 may guide the distal aspiration lumen of the catheter 512 to the target anatomy and clot site. In some embodiments, the curved distal section of the catheter 512 may allow for increased deflection (e.g., angulation) as the cannula 514 is exposed more. In some embodiments, the expandable tip 513 and the shaped distal section may be formed from a single piece of nitinol tube with one or more different cutting patterns (e.g., laser cutting patterns) in the different sections, thereby eliminating a joint between the two sections.

In some embodiments, the distal end of the shaft 510 may be shaped (e.g., bent, curved, or otherwise have a non-linear shape) to facilitate orbital movement of the shaft 510 within the lumen of the expandable tip 513. For example, the shaft 510 may have a bend or curve at a point near its distal end. In some embodiments, the shaft 510 may have a preformed shape (e.g., have preformed bends or curves). Additionally or alternatively, a stylet (e.g., stylet 216, described above with reference to fig. 4) may be used to impart a shape on shaft 510. Negative pressure (e.g., applied via a vacuum source) and/or axial and orbital rotation of shaft 510 may draw clot proximally within the lumen of catheter 512. The orbital motion of the shaft 510 within the catheter 512 may facilitate hydrodynamic and direct mechanical interaction with the clot at a predetermined rate, thereby reshaping (e.g., elongating) and macerating the clot to improve aspiration and transport.

In some embodiments, catheter 512 may have an expandable tip 513 having a funnel shape with a larger diameter lumen. The larger diameter of the catheter lumen at the expandable end 513 may enable thrombus to be drawn into the expandable end 513 without significant compression or compression, which may, for example, facilitate easier disruption or remodeling of the thrombus by the shaft 510. Additionally, a larger diameter of the catheter lumen may increase the engagement force with the thrombus and the uptake depth of the thrombus (e.g., the depth of proximal movement of the thrombus within the catheter lumen). In some embodiments, the maximum diameter of the catheter lumen at the expandable end 513 may be at least about twice the diameter of the catheter lumen proximal of the expandable end 513. In some embodiments, the maximum diameter of the catheter lumen at the expandable end 513 may be about 1.5 times to about 5 times the diameter of the catheter lumen proximal of the expandable end 513, including all subranges and values therebetween. In some embodiments, an increase in the diameter of the catheter at the expandable end 513 of about two times (e.g., 12French to 24 French) may increase the engagement force of the catheter 513 with the thrombus by about four times. In some embodiments, the expandable tip 513 may accelerate the clot to the shaft 510 that is safely positioned within the catheter lumen. In particular, shaft 510 may be positioned within a catheter lumen and rotated axially and along a track to engage and disrupt a clot. The distal end of the shaft 510 may extend into the expandable tip 513 of the catheter 512 such that the shaft 510 may engage (e.g., via a force and/or suction created by the rotating shaft 510) a clot that is pulled into the expandable tip 513.

Fig. 6 is a cross-sectional side view of a thrombectomy system 600 including a shaft 610 disposed within a lumen of a catheter 614. The shaft 610 and the catheter 614 may be similar in structure and/or function to other shafts and catheters described herein.

The catheter 614 may have an expandable end with a first section 615 that is coupled to a main shaft (not depicted) of the catheter assembly and may be shaped to provide rotational directionality and/or maneuverability. For example, the first section 615 may have a bend or curve that then places the more distal section of the expandable tip at an angle relative to the longitudinal axis of the catheter 614. The expandable tip may have a second section 616 of increased diameter. The second section 616 may have a hoop strength sufficient to prevent collapse under negative pressure (e.g., generated by a vacuum source) and a strength sufficient to prevent damage to the shaft 612 as the shaft 612 rotates within the conduit 614. The expandable tip may have a third section 618 that is an atraumatic region having a strength that is flexible enough to prevent vascular injury but strong enough to prevent collapse under negative pressure (e.g., generated by a vacuum source).

In one embodiment, the expandable tip may include an inner metallic structure (e.g., similar to a stent structure) and an outer cover or membrane structure. In some embodiments, the expandable end may be formed of a shape memory alloy or polymer that expands upon release or deployment from a cannula (e.g., cannula 218). The expandable end may be formed using a laser cut tube, braid, coil, slot tube, or other suitable structure. In some embodiments, the expandable tip may have mechanical properties that vary along the length of the expandable tip. For example, the expandable tip may have a different laser cutting pattern in one or more of sections 615, 616, 618. Such different laser cutting patterns may be selected to provide different mechanical properties better suited for different uses, such as for bearing shaft joints, preventing collapse, atraumatic designs, etc.

In some embodiments, the expandable end may be formed from a braid, coil, or plurality of loops, each capable of transitioning from a collapsed state to an expanded state as a result of an applied force or a released constraining force. The braid configuration may allow for an application of an elongation force to the geometry to transition it to a smaller diameter state along the length of the expandable tip. The coil configuration may require a torsional load to be applied to allow for diameter changes. In some embodiments, the variation in density or pitch of the individual filiform elements of the coil or braid may allow for various hoop/buckle strengths along the length of the expandable tip.

In some embodiments, a cover or membrane of the inner metallic structure surrounding the expandable tip may define a continuously sealed lumen from the distal opening to the proximal attachment (e.g., to the proximal portion of catheter 614). The cover or membrane may be constructed of an elastic or inelastic material to accommodate expansion or collapse. The substantially inelastic material may include PTFE, expanded PTFE (ePTFE), FEP, PET, or the like. These materials may provide lower friction characteristics, advantageously allowing the clot to pass proximally and reducing wear associated with the interaction with the rotational shaft 612. The elastic material may include thermoplastics (e.g., polyurethane, pebax, polyolefin, nylon, etc.) and/or thermosets (e.g., silicone, bezels, polyurethane, etc.). In addition, a variety of materials may be used along the length or as layers to provide the desired mechanical properties. In one embodiment, a thin ePTFE coating may be used. The cover or membrane material may be positioned on top of the support metal or stent-like structure. In this position, the material may act like a sock and not fixedly adhere to the stent. Suction applied to the catheter 614 and the associated pressure increase from the inner lumen to the outer body lumen can seal the sock-like sheath and adhere the material to the inner stent-like structure. In some embodiments, the sheath may be fixed or coupled to the inner stent-like structure on the outer surface, the inner surface, and/or completely enclose the stent-like structure. This can be achieved in various processes.

As depicted in fig. 6, the catheter 614 may have a first diameter 620 at a proximal end of the expandable tip and may have a second diameter 622 at a distal end of the expandable tip. The first diameter 620 may be smaller than the second diameter 622. In some embodiments, the second diameter 622 is at least twice the first diameter 620. In some embodiments, the second diameter 622 is about 1.5 times to about 5 times the first diameter 620, including all subranges and values therebetween. The catheter 614 may be designed to have a smaller profile (e.g., a 12French diameter when disposed within an outer cannula (such as, for example, cannula 218)) during insertion and navigation to the target site, and a larger profile (e.g., 24 French) during thrombectomy, such that the catheter 614 may engage and ingest the clot into the distal portion as effectively as a larger catheter. The larger diameter of the flared end portion may allow the catheter 614 to have a larger radial coverage within the body lumen. The larger diameter of the expandable tip, in combination with the diverging diameter of the second section 616 of the expandable tip, may facilitate clot engagement, acceleration, and uptake toward the first section 615 and further toward the proximal end of the thrombectomy system 600. The larger diameter of the expandable tip may achieve high clot engaging forces at equal suction pressure (e.g., negative pressure). The high clot engaging force may allow the clot to be further ingested into the tip of the catheter 614. The high clot engaging force may also allow the clot to be more effectively captured within the second section 616 and the third section 618 as compared to a catheter having a constant shaft diameter 620 extending entirely to the distal end. This greater engagement force due to the expanded second diameter 622 may facilitate pulling the entire device 614 proximally to remove the clot without disengaging from the distal end of the expandable tip.

Similar to shaft 510, shaft 612 may be configured to axially rotate and orbit within the lumen of the expandable end of catheter 614. The shaft 612 may be configured to engage a clot that is aspirated or ingested into the expandable end portion of the catheter 614, e.g., via negative pressure, and disrupt and/or remodel the clot for further ingestion toward the proximal end of the thrombectomy system 600. The shaft 612 may be positioned proximal to the distal end of the catheter 614 such that the shaft 612 is fully enclosed and prevented from engaging the walls of the body lumen (which may damage natural topographies) or freely rotating in the blood-filled body lumen (which may cause hemolysis). Instead, the shaft 612 is configured to axially rotate and orbit within the third section 618 of the expandable tip to engage and aspirate a clot. In some embodiments, the distal end of the shaft 612 may be positioned within the expandable tip portion proximal to the point of the distal end of the catheter 614 but distal to the point where the clot will cease to move proximally due to suction alone.

Fig. 7A and 7B are detailed cross-sectional side views of a thrombectomy system 700. Thrombectomy system 700 may be similar in structure and/or function to other thrombectomy systems described herein and may include components similar in structure and/or function to other similar components described herein. For example, the thrombectomy system 700 may include a catheter 710, a shaft 720, and optionally a stylet 730. Catheter 710 may be similar in structure and/or function to other catheters described herein, shaft 720 may be similar in structure and/or function to other shafts described herein, and stylet 730 may be similar in structure and/or function to other stylets described herein.

Fig. 7A and 7B illustrate different movements of the shaft 720. When used with the stylet 730, the rotational and orbital movements of the shaft 720 can be decoupled from one another. . For example, the rotational direction of the orbital motion of the shaft 720 may be controlled to be the same as or different from the rotational direction of the axial motion of the shaft 720. Fig. 7A depicts a system 700 in which a shaft 720 rotates axially according to arrow 721 and moves along an orbit according to arrow 731, where the two arrows are in opposite directions. Rotational movement of the shaft 720 about its axis may be caused by rotating the shaft 720, and orbital movement of the shaft 720 about the longitudinal axis of the catheter 710 may be caused by rotating the stylet 730. Thus, by rotating shaft 720 and stylet 730 in different directions, this can cause shaft 720 to rotate axially (e.g., about its longitudinal axis) in a first direction and to move orbitally (e.g., about the longitudinal axis of catheter 710) in a second direction opposite the first direction. As described above, the drive system (e.g., drive system 132, 232) may be configured to independently rotate the shaft 720 and the stylet 730 in a predetermined rotational direction and speed.

Alternatively, in some embodiments, the shaft 720 may rotate axially and move along the track in the same direction, as depicted in fig. 7B. For example, shaft 720 may be axially rotated (e.g., about its longitudinal axis) according to arrow 723, and the shaft may be orbitally moved (e.g., orbitally moved about the longitudinal axis of catheter 710) according to arrow 731. In this case, the shaft 720 and the stylet 730 can be rotated in the same direction to cause axial and orbital movement in the same direction. The rotational speeds of the shaft 720 and the stylet 730 can be the same or varied to provide the desired rotational speed of axial movement and/or orbital movement.

As depicted in fig. 7A and 7B, the shaft 720 and/or the optional stylet 730 can have a curved or bent distal portion. In some embodiments, the shaft 720 may be substantially linear, but when a stylet 730 having a preset curvature is inserted into the shaft 720, the shaft 720 may assume a curved shape defined by the stylet 730. Alternatively or in addition, the shaft 720 may be formed to have a preset shape (e.g., a curved portion or a bent portion).

In some embodiments, the shaft 720 may be rotated without the stylet 730. When rotated at a sufficient speed, the shaft 720 may exhibit an orbital motion. Additionally or alternatively, the shaft 720 may have a preset shape (e.g., a bend or kink) that may set the distal end of the shaft at an angle relative to the more proximal portion of the shaft. The distal end of the shaft 720 then assumes an orbital motion as the shaft 720 rotates. In this case, the orbital motion of the shaft 720 is coupled with the rotational motion of the shaft 720. In other words, the orbital and rotational movement of the shaft 720 may occur in the same direction and at speeds proportional to each other.

In fig. 7A and 7B, the distal end of the shaft 720 may be disposed proximal of the distal end of the catheter 710 (and the distal end of the stylet 730 may also be disposed proximal of the distal end of the catheter 710 if an optional stylet 730 is present). In some embodiments, the shaft 720 and/or stylet 730 can be disposed within the expandable end 711 of the catheter 710. In some embodiments, the distal end of the shaft 720 may rotate within the expandable tip 711 such that a diameter associated with the orbital path of the distal end of the shaft 720 may be greater than a diameter of a more proximal portion of the catheter 710. In some embodiments, the distal end of the shaft 720 is rotatable within the expandable tip 711 such that the inner diameter of the expandable tip 711 can constrain the distal end of the shaft 720 such that the radius 731 of the orbital motion is defined by the inner diameter of the expandable tip 711. Similar to the expandable distal portions or tips of the catheters described above (e.g., catheter 512 and catheter 614), the larger diameter of the expandable tip 711 may facilitate clot engagement, acceleration, and uptake toward the proximal end of the thrombectomy system 700.

Fig. 8A and 8B are front cross-sectional views of a thrombectomy system 800 depicting axial and orbital movement of a shaft. Thrombectomy system 800 may be similar in structure and/or function to other thrombectomy systems described herein and may include components similar in structure and/or function to other similar components described herein. For example, thrombectomy system 800 may include a catheter 810, a shaft 820 disposed within a lumen of the catheter 810, and optionally a stylet 830 disposed within the lumen of the shaft 820. Catheter 810 may be similar in structure and/or function to other catheters described herein, shaft 820 may be similar in structure and/or function to other shafts described herein, and stylet 830 may be similar in structure and/or function to other stylets described herein.

Fig. 8A illustrates axial rotation 821 of shaft 820 about a central longitudinal axis of shaft 820. The axial rotation 821 of the shaft 820 may be generated by applying a rotational force to the shaft 820. Fig. 8B shows orbital movement 823 of shaft 820 along the inner circumference of catheter 810. Orbital rotation 823 of shaft 820 may be generated by applying a rotational force to stylet 830. The shaft 820 may rotate and orbit within the expandable end of the catheter 810. In some embodiments, the orbital path of the distal end of the shaft 820 may be spaced apart from the inner surface of the expandable tip by a distance D, while in other embodiments, the orbital path of the distal end of the shaft 820 may be adjacent to the inner surface of the expandable tip. In some embodiments, the shaft 820 may move in a non-circular but may vary or be irregular orbital path based on engagement between the shaft 820 and thrombus.

Fig. 9 is a side view of the distal end of a catheter 900 that includes a collar 910 with a high density or solid wall attachment portion, an expanded or funnel-shaped portion 920, a cylindrical portion 930, and an atraumatic portion 940. Collar 910 may be attached to the body of catheter 900. The cylindrical portion 930 may have larger struts or braids or loops to provide hoop strength, buckle strength, and basket toughness. Funnel shaped portion 920 may have variations in the size of struts, braids, or coils similar to cylindrical portion 930 with respect to its diameter at various funnel cross-sections. Atraumatic portion 940 may be formed of a thinner wire or element and may provide a spring-like safety tip and a substantially flat distal surface. The strength of the expandable tip may be designed to resist collapse by a given negative pressure, and the strength may be varied at different points along the length of the expandable tip to account for different forces generated by the negative pressure at different diameters.

Fig. 10 is a side view of the distal end of a catheter 1000 including different sections 1010, 1020, 1030 having different diameters D1, D2, and D3, respectively. As the diameter increases, the collapsing force exerted by the vacuum pressure exerted within the lumen of the expandable tip along the different sections 1010, 1020, 1030 may increase proportionally. Thus, the expanded end of increased diameter may be designed to have greater strength to withstand the greater forces exerted by the vacuum pressure. In some embodiments, the different sections 1010, 1020, 1030 may be designed with different structural patterns that impart different strength to the different sections 1010, 1020, 1030 based on increasing forces as the diameter increases, similar to the structural patterns described for expanding the end portions 920, 930, 940.

In some embodiments, the pattern of the expansion end can be configured such that the pattern is substantially the same along its length when in the compressed configuration. Such a pattern may provide increased collapse resistance with greater radial expansion. In such a design, the struts or wire angles may be more blunt and circumferential in orientation in the expanded configuration (e.g., maximum expanded state) and may be more sharp or longitudinally oriented in the retracted configuration (e.g., minimum expanded state). In another embodiment, the support structure pattern may be configured such that the layout and strut dimensions are different in both the expanded and retracted configurations along the length of the expandable end section.

FIGS. 11A to 11C areA cross-sectional side view of the distal end of the thrombectomy system including a catheter 1150 disposed within the sleeve 1140. Fig. 11A depicts a distal end 1160 (e.g., an expandable tip) of the catheter 1150 that initially expands to a first diameter D when pushed out of (e.g., deployed from) the sleeve 1140 at 1110 ₁ . Fig. 11B depicts the distal end 1170 of the catheter 1150 expanding to a second diameter D when pushed out of (e.g., deployed from) the sleeve 1150 at 1120 ₂ . For example, the diameter of the distal end 1170 may increase in a stepped fashion. Fig. 11C depicts a distal end 1180 of the catheter 1150 that expands to a third diameter D when pushed out of (e.g., deployed from) the sleeve 1150 at 1130 ₃ . A force F (e.g., suction) may be applied to the clot 1190 to draw the clot 1190 into the expanded diameter D ₃ To facilitate thrombus removal.

In some embodiments, the expandable end portions of the catheters described herein may be configured to be of a length and a variable diameter to allow for varying diameters at different exposures of the inner lumen of the outer sleeve (e.g., sleeve 218). This may be accomplished by a stepped diameter configuration or by increasing exposure of the diverging angle of the proximal section of the funnel. Such adjustment or dial-in of the dilation ratio enables the catheter to be scaled up or down to navigate larger or smaller vessel lumens, respectively. Expandable openings of various diameters can also vary the distal cross-sectional area and associated clot engaging forces. Such a configuration may provide benefits where the distal vessel has a thinner wall and generally requires more safety considerations. A smaller force on the elements of the distal anatomy may be desired, and a smaller diameter of the expandable portion may help achieve this.

Fig. 12A-12C are cross-sectional side views of the distal end of a catheter assembly 1200 that includes a set of nested catheters that includes a first catheter 1210, a second catheter 1220, and a third catheter 1230. Fig. 12A depicts catheter assembly 1200 in an undeployed configuration in which each of the distal ends of catheters 1210, 1220, 1230 are substantially aligned. Fig. 12B depicts the catheter assembly 1200 in which the second catheter 1220 is deployed into an expanded configuration in which the diameter of the distal end of the second catheter 1220 increases as it is pushed out of the first catheter 1210. Similarly, fig. 12C depicts the catheter assembly 1200 in which the third catheter 1230 is deployed into an expanded configuration in which the diameter of the distal end of the third catheter 1230 increases as it is pushed out of the first catheter 1210 and the second catheter 1220. The nested catheter configuration may allow a user (e.g., physician) to selectively deploy the catheter assembly 1200 at a plurality of different distal diameters. Although not depicted, the catheter assembly 1200 depicted in fig. 12A-12C may be used with any of the shaft assemblies described herein, as well as components of such shaft assemblies. The proximal end (not depicted) of the catheter assembly 1200 may also include a handle assembly, an adjustment element, and/or other components associated with the catheter assemblies described herein (e.g., the catheter assembly 100).

Fig. 13A and 13B are cross-sectional side views of a distal end of a catheter assembly 1300 including a catheter 1330 disposed within a cannula 1320. Catheter assembly 1300 may include components similar in structure and/or function to other catheter assemblies described herein, and may be used with any of the shaft assemblies described herein. Fig. 13A depicts a distal end 1340 (e.g., an expandable tip) of a catheter 1330 that initially expands to a first diameter D when pushed out of (e.g., deployed from) or exposed to the exterior of a cannula 1320 at 1300 ₁ . Fig. 13B depicts the distal end 1340 of the catheter 1330 that expands to the second diameter D when pushed out of (e.g., deployed from) the cannula 1320 at 1310 or exposed to the outside of the cannula ₂ . Second diameter D ₂ Can be larger than the first diameter D ₁ . The distal end 1340 may have a shape with a diameter that increases as a greater portion of the distal end 1340 is exposed. For example, the distal end 1340 may have a tapered shape. This increased diameter may allow a user (e.g., physician) to selectively deploy catheter assembly 1300 at a plurality of different distal diameters, e.g., based on the distance catheter 1330 is deployed outside cannula 1320.

Fig. 14A-14D are perspective views of catheter assemblies of a thrombectomy system, each catheter assembly having a self-expanding funnel-shaped tip. The catheter assembly may include components similar in structure and/or function to other catheter assemblies described herein, and may be used with any of the shaft assemblies described herein. Fig. 14A depicts a catheter that includes an expandable distal tip 1419 that gradually increases in diameter over the entire length of the tip 1419. Fig. 14B depicts a catheter including an expandable distal tip 1419' having a proximal section with a first diameter, a distal section with a second diameter, and a central section increasing in diameter from the first diameter to the second diameter. Each of the ends 1419, 1419' may have a plurality of sections with different cutting patterns formed by the holes. For example, the number of proximal holes of the tip may be smaller and larger, while the number of distal holes may be larger and smaller. In some embodiments, when the expandable tip is in a compressed or unexpanded configuration, the proximal-most side hole of the tip may have a length of about 2mm, and the distal-most side hole of the tip may have a length of about 5 mm. In some embodiments, the proximal-most side hole of the tip may have a proximal angle of about-10 ° and the distal-most side hole of the tip may have a proximal angle of about 40 ° when the tip is in the expanded configuration. The holes between the proximal-most hole and the distal-most hole may have a length and/or angle therebetween, wherein the length and/or angle of each row of holes increases progressively from proximal to distal.

Fig. 14C-14D depict a distal end of a catheter assembly including a catheter 1418 having an expandable distal tip 1419 "with a proximal section that gradually increases in diameter to a distal section having a cylindrical (or substantially cylindrical) profile. Both expandable ends 1419' and 1419 "have atraumatic shapes to facilitate movement of the catheter within the body lumen. The tip 1419 "may be configured to self-expand as it is pushed out of the sleeve or sheath 1416.

In fig. 14C-14D, the distal portion of the catheter 1418 can be shaped to direct the distal end or expandable tip 1419 "at a predetermined angle relative to a more proximal section of the catheter 1418 (e.g., a section disposed within the cannula 1416). For example, the catheter 1418 can include a bend or curve 1417 that sets the expandable tip 1419 "at an angle relative to the longitudinal axis of the proximal section of the catheter 1418. The angle may be from about 10 degrees to about 90 degrees, including all subranges and values therebetween. In some embodiments, the angle can be adjusted, for example, by actuating a pull wire coupled to the distal end 1419 of the catheter 1418 and/or by deploying the catheter 1418 outside of the cannula 1416 at a selected distance (e.g., by further deployment creating a greater angle). In some embodiments, the angle may be fixed, for example, by forming the catheter from a shape memory material having a predetermined bend or curve. The stiffness of the preset bend or curve 1417 can be designed based on the stiffness of the cannula 1416 such that the cannula 1416 is straight or, in some embodiments, presents a portion of the curve from the curve 1417 when the catheter 1418 and expandable tip 1419 "are fully retracted into the cannula 1416. In some embodiments, the catheter 1418 can be rotated, e.g., via an arrow depicted in fig. 14C, to position the distal end 1419″ of the catheter 1418 at different locations within the body lumen. In other words, the catheter 1418 can be rotated to steer and/or sweep the distal end 1419″ of the catheter 1418 within the body lumen, for example, to target a thrombus.

Fig. 21A-21C are perspective views of additional embodiments of catheter assemblies of a thrombectomy system according to embodiments, each catheter assembly having a flexible cover over a self expanding tip. The catheter assembly may include components similar in structure and/or function to other catheter assemblies described herein, and may be used with any of the shaft assemblies described herein. Fig. 21A depicts the distal end of the catheter including an expandable distal section that transitions to a tip 2119 having a conical or funnel shape. The tip 2119 may have a metal frame 2120 and a coating 2121 disposed thereon. The metal frame 2120 defines a plurality of openings. As depicted, the coating 2121 can have an inner layer and an outer layer connected to each other via open spaces (e.g., holes, pores) of the apertures. The plurality of openings in fig. 21A-21C increase in size from the proximal end to the distal end of the expandable tip 2119, similar to the other expandable tips described herein. The metal frame also includes atraumatic wave structure at the distal end of the expandable tip 2119. As shown in fig. 21A, a wave-like (e.g., wavy, U-shaped) structure may be formed of apertures having as many features (e.g., crowns) as half of the apertures of an adjacent proximal row such that the structure is coupled to the apertures of an adjacent row at every other crown. The reduced number of features at the distal end provides an atraumatic shape.

The expandable end 2119 may be configured to transition between a compressed or constrained configuration (e.g., when disposed within the cannula 2116) and an expanded configuration (e.g., when extended outside the cannula 2116). A flexible cover 2121 may be provided over the outer and inner surfaces of the tip 2119. By covering the opening of the expandable end 2119, the flexible cover 2121 can facilitate creating a negative suction within the expandable end 2119 to draw thrombus proximally within the catheter lumen. In some embodiments, the flexible cover 2121 may be configured to extend distally from the distal end of the metal frame, e.g., to further assist in providing atraumatic structure at the distal end of the catheter.

Fig. 21B depicts a shaft 2130 within the lumen of the expandable tip 2119. The shaft 2130 may be similar in structure and/or function to other shafts described herein. For example, the shaft 2130 may be configured to rotate within a catheter with an end of the shaft disposed within the expandable tip 2119 of the catheter. The shaft 2130, via its placement and rotation, may be configured to remodel a thrombus drawn into the expandable end, e.g., to further facilitate its proximal movement and removal from the lumen of a vessel.

Fig. 21C depicts a distal end of a catheter assembly according to an embodiment. The distal end may be configured to be directed (e.g., maneuvered) toward a predetermined target (e.g., thrombus) in a body lumen by rotating the catheter and/or cannula. Similar to fig. 14C, fig. 21C depicts a catheter having a bend or curve 2117 that rotates to manipulate the expandable end 2119 of the catheter. Further, the cannula 2116 provided on the catheter assembly may include a bend or curve. The curvature of the cannula 2116 can interoperate with the curvature 2117 of the catheter, for example, to provide additional control over the positioning of the expandable tip 2119. For example, the curvature of the cannula 2116 and the curvature 2117 of the catheter may operate together to set the distal end of the catheter at an angle relative to the longitudinal axis of the more proximal linear section of the cannula and catheter. The angle may be from about 10 degrees to about 90 degrees, including all subranges and values therebetween. In some embodiments, the angle may be adjusted or changed, for example, by actuating a pull wire coupled to the cannula 2116, by changing the amount or distance the curved portion of the catheter extends out of the cannula 2116, by changing the direction of the curve of the curved portion of the catheter relative to the curved portion of the cannula, and so forth. In some embodiments, the angle may be fixed, for example, by forming sleeve 2116 with a predetermined bend or curve. In some embodiments, the curvature of cannula 2116 can be opposite the curvature of curved portion 2117 of the catheter, such that, for example, the distal end of the catheter can generally follow the longitudinal axis of the catheter. The stiffness of the preset bend or curve may be designed based on the stiffness of sleeve 2116. As shown in fig. 21C, sleeve 2116 can be rotated to position the distal end of the catheter at different locations within the body lumen. Thus, fine adjustment of the position and angle of the catheter may be provided by rotation of the catheter and/or the cannula. Such adjustment may facilitate navigation of the catheter assembly through the vasculature of the patient and/or positioning of the distal end of the catheter assembly for optimal engagement and capture of the clot.

Fig. 21D depicts a distal end of a catheter assembly according to an embodiment. The expandable end 2119 in the expanded configuration includes a metal frame 2020 defining a plurality of apertures 2122. For clarity, the coating on the metal frame 2020 is not shown in fig. 21D. In some embodiments, each aperture of the plurality of apertures 2122 has at least about 0.5mm ² Such that the inner layer and the outer layer of the coating are capable of being connected to each other at each aperture. As shown in fig. 21D, the plurality of apertures 2122 increase in size from the proximal end to the distal end of the expandable tip 2119. The metal frame may also include atraumatic wave ring 2123 at the distal end of the expandable tip 2119. In the compressed configuration of the expandable end 2119 shown in fig. 21E, the ring 2123 may have a generally repeating U-shape. The ring 2123 may generally be flexible and atraumatic to reduce and/or prevent damage to tissue.

In some embodiments, the openings may beConfigured to have dimensions (e.g., length, area) and angles configured to resist collapse of the expandable end 2119 under vacuum while allowing the expandable end 2119 to collapse as the aspiration catheter is withdrawn into the cannula. In some embodiments, when the expandable tip is in the expanded configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip 2119 may have a proximal angle of about-10 ° to about 0 °, including all subranges and values therebetween, and an aperture of the plurality of apertures disposed at the distal end of the expandable tip may have a proximal angle of about 20 ° to about 40 °, including all subranges and values therebetween. In the context of this example, a negative angle represents an angle that decreases from the proximal end to the distal end of the expandable tip 2119. In some embodiments, each row of apertures has a different angle. For example, as depicted in fig. 21D, the proximal-most aperture may have a negative proximal angle θ ₁ Such as from about-10 deg. to about-0 deg., including about-5 deg.. The more distal apertures may have a greater than proximal angle θ ₁ Is a proximal angle theta of (2) ₂ Such as from about 0 deg. to about 20 deg., including about 15 deg.. The openings further apart may have an angle θ greater than the proximal side ₂ Is a proximal angle theta of (2) ₃ For example, about 20 ° to about 40 °, including about 30 °. Similarly, the additional distal aperture may have an angle θ with the proximal side ₁ 、θ ₂ 、θ ₃ Different proximal angles θ ₄ And a proximal angle θ ₅ . In some embodiments, the more distal rows of apertures may have a greater proximal angle than the more proximal rows of apertures. In some embodiments, the plurality of rows of apertures from proximal to distal may increase in proximal angle (e.g., about 2 to about 20, including all values and subranges therebetween) for a predetermined number of rows, and then remain substantially the same in the distal section of the expandable tip 2119. For example, as depicted in fig. 21D, the proximal angle θ ₁ 、θ ₂ 、θ ₃ Can be increased, while the proximal angle θ ₃ 、θ ₄ 、θ ₅ May remain substantially the same.

The expanded open cell structure with proximal angle as depicted in fig. 21D may result from multiple rows of open cells having different longitudinal lengths when unexpanded (i.e., in an unexpanded or retracted configuration). Fig. 21E depicts a plan cut-away view of the distal end of a catheter assembly according to an embodiment. The plan cut-away view shows the geometry of the opening of the expandable end 2119 in its unexpanded state. In the unexpanded state, the apertures of the plurality of apertures 2122 disposed at the proximal end of the expandable tip 2119 may have a length of about 0.5mm to about 3mm, including about 2mm and other values or subranges therebetween, and the apertures of the plurality of apertures 2112 disposed at the distal end of the expandable tip 2119 may have a length of about 3mm to about 10mm, including about 5mm and other values or subranges therebetween. For example, when the expandable tip 2119 is in the retracted configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip 2119 may have a length of at least about 2mm, and an aperture of the plurality of apertures disposed at the distal end of the expandable tip may have a length of less than about 5 mm. In some embodiments, the longitudinal length of the openings of the most distal row may be about 2 to about 10 times (including about 5 times) the longitudinal length of the openings of the most proximal row, including all values and subranges therebetween. The plurality of apertures 2122 may be arranged in offset rows, wherein each row may be offset from its adjacent row by about 50%. The expandable end 2119 may be expanded by arranging its openings 2122 in an offset row such that the openings 2122 are diamond-shaped (or substantially diamond-shaped) when expanded.

In some embodiments, the catheter shaft may include a first coating (e.g., pebax) and the metal frame of the expandable end 2119 may include a second coating (e.g., PTFE or ePTFE), wherein the second coating is more flexible than the first coating. The first coating may be low friction to facilitate proximal thrombus movement through the catheter assembly, while the second coating is relatively more flexible to facilitate reducing the bending stiffness of the distal end. In some embodiments, the expandable end 2119 may be joined to the first portion 2140 of the catheter shaft. The first portion 2140 of the catheter shaft may be or include a curved or bent section (e.g., curved section 318). In some embodiments, the first portion 2140 and the expandable end 2119 may be formed from a single metal tube (e.g., nitinol tube). In some embodiments, the first portion 2140 of the catheter shaft may be coupled to a more proximal portion (e.g., the linear section 314) of the catheter shaft formed of a different material (e.g., stainless steel). Thus, in some embodiments, the first portion 2140 of the catheter shaft may have different material properties than a more proximal portion of the catheter shaft.

Fig. 15A-15E are schematic illustrations of a distal end of a catheter assembly of a thrombectomy system according to an embodiment. The catheter assembly may include components similar in structure and/or function to other catheter assemblies described herein, and may be used with any of the shaft assemblies described herein. Fig. 15A depicts a radius of curvature R of a distal portion of a suction catheter 1510 that enables a distal opening of the catheter to be directed (e.g., at an angle a) at a target anatomy such as a clot. By rotating the suction catheter with a curved distal portion, the suction catheter 1510 can effectively sweep the inner circumference of the blood vessel, thereby facilitating complete or greater scope of clot engagement and removal. By rotating the curved aspiration catheter, the distal tip can be selectively directed or maneuvered toward, for example, the ostium of a target vessel to advance into the vessel.

Fig. 15B depicts a side view of the aspiration catheter 1520 having an asymmetric distal end that provides a relatively large swept diameter when rotated about the longitudinal axis of the catheter 1520. Fig. 15C shows a front view of aspiration catheter 1520 with the opening of the distal end (e.g., the expandable tip) offset relative to the longitudinal axis of the proximal linear portion of catheter 1520 (represented by the "+" symbol). Fig. 15D illustrates the orientation of the aspiration catheter 1530 (e.g., similar to catheter 1520) in two positions (i.e., 0 °, 180 °) when rotated about its longitudinal axis, and fig. 15E is a front view of the coverage area of the aspiration catheter with the body lumen of the rotating aspiration catheter 1530. As depicted, rotation of the catheters 1510, 1520, 1530 may facilitate greater coverage within a larger body lumen, thereby allowing the user to sweep within the body lumen to target more area to remove thrombus and/or selectively direct the distal end to a target thrombus or target vessel.

In some embodiments, the aspiration conduits 1510, 1520, 1530 may include one or more of slits, stent patterns, shaped polymers, shape memory alloys, and the like. In some embodiments, one or more pull wires may be configured to deflect the distal end. For example, a longitudinal backbone without compression capability and a slotted flexible section positioned 180 degrees from the backbone on a cylindrical portion of the distal pattern would allow a pull wire attached to the distal tip of the catheter on the flexible side to be forced back, compressing the flexible portion and imparting a tip bend to the catheter 1510, 1520, 1530.

Fig. 16A and 16B are images of a thrombectomy system 1600 navigated through a model vasculature, including through the inferior vena cava, right atrium, and right ventricle of a patient's heart. The thrombectomy system depicted in fig. 16A and 16B may include components similar in structure and/or function to other thrombectomy systems described herein. For example, a thrombectomy system may include an outer cannula 1602 and a catheter 1604. In fig. 16A and 16B, the distal end of the catheter may have been deployed (e.g., from within the cannula) such that it has an expanded configuration to facilitate thrombus removal. In use, the catheter may be navigated to a thrombus site while within the outer sleeve constraining it to a smaller diameter, and then once at the thrombus site, may be deployed from the sleeve (e.g., by retracting the sleeve relative to the catheter) to allow the distal end of the catheter to expand to the expanded configuration shown in fig. 16A and 16B.

Handle assembly

Fig. 17A-17D are cross-sectional views of a proximal end of a thrombectomy system according to an embodiment. The thrombectomy system may include components similar in structure and/or function to other thrombectomy systems described herein. The thrombectomy system may include a handle assembly 1700 that includes a first adjustment mechanism 1710 (e.g., a first catheter adjustment mechanism), a second adjustment mechanism 1720 (e.g., a second catheter adjustment mechanism), a connector 1730, and ports 1740, 1742. The handle assembly 1700 may be coupled to a drive unit 1750 that includes a shaft 1760. In some embodiments, the first adjustment mechanism 1710 can be configured to translate the sleeve 1718 and/or the catheter 1714 (e.g., a suction catheter) relative to the handle assembly 1700. In some embodiments, the second adjustment mechanism 1720 can be configured to rotate the catheter 1714 about a longitudinal axis of the catheter. The adjustment mechanisms 1710, 1720 may be implemented as knobs, rollers, sliders, slides, combinations thereof, and the like. For example, the second adjustment mechanism 1720 can be implemented as a knob that can be rotated to enable rotation of the catheter 1714, and the first adjustment mechanism 1710 can be a thumb wheel configured to translate the cannula 1718 relative to another cannula 1714. In some embodiments, the adjustment mechanisms 1710, 1720 can be configured to maintain a position between the aspiration catheter 1714 and the cannula 1718 when not adjusted.

The port 1740 may be configured to receive a guidewire (not shown) such that the catheter 1714 and the cannula 1718 may be advanced over the guidewire to a target site. Port 1742 may be a vacuum port for coupling to a vacuum source such that a negative pressure may be created within the lumen of catheter 1714.

In some embodiments, drive unit 1750 may be configured to be coupled to connector 1730. The drive unit 1750 can support a shaft 1760 (and optionally a stylet), for example, which can be inserted and advanced through the interior lumen of the catheter 1714 after the catheter 1714 has been positioned within the body lumen. The drive unit 1750 may be configured to rotate one or more of the shaft 1760 and a stylet (not shown) disposed within the shaft 1760. For example, drive unit 1750 may include a concentric bearing assembly that allows for driving shaft 1760 and stylet from a parallel offset motor via gears and/or belts.

Although only some internal components of the handle assembly 1700 are depicted and described herein, it is to be understood that the handle assembly 1700 may include components similar in structure and/or function to the components of other handle assemblies described herein (e.g., the handle assembly 160, the drive unit 140, the drive system 232). For example, the handle assembly 1700 may include a power source (e.g., a battery), one or more seals, and the like. The handle assembly 1700 may include one or more seals to inhibit suction leakage.

The drive unit 1750 may include components similar in structure and/or function to components of other drive units (e.g., drive unit 140, drive system 232) described herein. In some embodiments, the drive unit 1750 may comprise two drive motors, each independently driving rotation of one of the shaft 1760 or stylet. In some embodiments, the drive unit 1750 may comprise a single motor that drives the shaft 1760 and optionally the stylet rotation. The drive unit 1750 may include an actuation mechanism (not shown) that may be pushed to control the drive system to drive rotation of the shaft 1760 and/or stylet. The shaft 1760 may be similar in structure and/or function to other shafts described herein, and the stylet may be similar in structure and/or function to other stylets described herein. For example, the shaft 1760 can include a lumen within which the stylet is disposed, and the stylet can include a shaped distal end that, when positioned within the shaft 1760, can cause the shaft 1760 to assume a shape that corresponds to the shape of the shaped distal end of the stylet. In some embodiments, the shaft 1760 can be used without a stylet. In such embodiments, the shaft 1760 can include a preset shape (e.g., a bend or curve), such as for enhancing the orbital motion of the distal end of the shaft 1760. In some embodiments, the handle assembly 1700 and/or the drive unit 1750 can be coupled to a fluid conduit configured to purge air from the suction conduit 1714, the shaft 1760, and/or the stylet (e.g., prior to use).

When the drive unit 1750 is coupled to the handle assembly 1700, the shaft 1760 (and optionally the stylet) can be positioned within the catheter 1714 such that the distal end of the shaft 1760 (and optionally the stylet) is positioned proximal to the distal end of the catheter 1714. In some embodiments, the distal end of the shaft 1760 (and optionally the stylet) can be positioned within the expandable tip of the catheter 1714, as described in other embodiments herein. In use, the catheter 1714 can be navigated (e.g., with the cannula 1718 over the catheter 1714) to a target site and deployed (e.g., by retracting the cannula 1718 and/or extending the catheter 1714 beyond the cannula 1718), and the shaft 1760 (and optionally a stylet) can be advanced through the lumen of the catheter 1714 until the drive unit 1750 engages the handle assembly 1700 (e.g., via the connector 1730). The drive unit 1750 may then be coupled to the handle assembly (e.g., via connector 1730), for example, by a twist lock or a push lock interface. After the drive unit 1750 is fully coupled to the handle assembly 1700, the shaft 1760 (and optionally the stylet) is then positioned for thrombectomy, e.g., for rotation within a catheter to remove thrombus, as described above. In some embodiments, finer adjustment of the position of the shaft 1760 and/or stylet may be achieved by one or more actuation mechanisms coupled to the drive unit 1750 and/or adjusting the coupling between the drive unit 1750 and the handle assembly 1700 (e.g., by tightening or loosening the drive unit 1750 to change the relative position of the drive unit 1750 with respect to the handle assembly 1700).

Fig. 19 is a perspective view of a proximal end of a thrombectomy system according to an embodiment. The thrombectomy system may include components similar in structure and/or function to other thrombectomy systems described herein. The thrombectomy system may include a handle assembly 2200 that includes a first adjustment mechanism 2212 (e.g., a first handle adjustment mechanism) that includes a slider, a second adjustment mechanism 2220 (e.g., a second handle adjustment mechanism), and a sleeve 2218. First adjustment mechanism 2212, second adjustment mechanism 2220, and sleeve 2218 may be similar in structure and/or function to first adjustment mechanism 1712, second adjustment mechanism 1720, and sleeve 1718, and thus are not described in detail herein. The handle assembly 2200 may be coupled to a drive unit 2250 that supports the shaft 2260. Additionally, the handle assembly 2200 may be coupled to a vacuum source via a port 2242.

Although the handle assembly 2200 and the drive unit 2250 are similar to other handle assemblies and drive units described herein, and in particular similar to those depicted in fig. 17A-17D, the handle assembly 2200 and the drive unit 2250 are configured to be coupled to one another in a different manner than shown in fig. 17A-17D. In particular, the drive unit 2250 is configured to be coupled to the handle assembly 2200 at a location extending along the longitudinal axis of the catheter and sheath. Thus, the shaft 2260 is configured to extend linearly (or substantially linearly) into the lumen of the catheter along the length of the handle assembly 2200. In fig. 19, the drive unit 2250 is shown separated from the handle assembly 2200 with the shaft 2260 partially inserted into the handle assembly 2200. In operation, the shaft 2260 may be inserted into the handle assembly 2200 and advanced along the length of the catheter until the drive unit 2250 may be coupled to the handle assembly 2200.

When the drive unit 2250 is not coupled to the handle assembly 2200, the portion 2244 may be coupled to the handle assembly 2200. Port 2244 may be configured for one or more of fluid flushing and contrast injection. Port 2244 may also be used to receive a guidewire, for example, to facilitate advancement of a catheter over the guidewire during navigation to a target site. In use, the handle assembly 2200 with the port 2244 coupled to the handle assembly 2200 as shown may be guided to a target site, for example, along a guidewire. The first adjustment mechanism 2212 can be retracted proximally to extend a catheter distal end (e.g., an expandable distal tip of a catheter) out of the sleeve 2218 such that the distal end is disposed within the vessel lumen. The second adjustment mechanism 2220 can also be rotated to adjust the positioning of the catheter distal end, for example, as a result of adjusting the direction of a bend or curve in the catheter. Alternatively, fluid may be delivered through port 2244 at some point before, during, or after the catheter is navigated to the target site. The port 2244 may then be removed and the shaft 2260 may be inserted into the handle assembly 2200 (e.g., where the port 2244 was previously coupled) until the drive unit 2250 may be coupled to the handle assembly 2200. Once the drive unit 2250 is coupled to the handle assembly 2200, the distal end of the shaft 2260 may be positioned within the catheter lumen near the distal end of the catheter (e.g., within the expandable tip of the catheter).

In some embodiments, the handle assembly 2200 may include a vacuum interrupter or vacuum valve 2270 configured to control the application of negative suction through the catheter. For example, the vacuum interrupter 2270 may be a switch configured to selectively actuate suction (e.g., pulsed suction and/or metered flow). In some embodiments, the negative suction may be applied when the operator engages the activation element and stops when the activation element has been released. In some embodiments, the vacuum interrupter 2270 may also be configured to control shaft rotation. For example, shaft rotation may be actuated after negative suction has been activated by vacuum interrupter 2270. In an example implementation, the vacuum interrupter 2270 may be configured to (1) activate a vacuum pressure in response to being pressed a first amount, and (2) activate the drive system 2250 to rotate the shaft in response to being pressed a second amount that is greater than the first amount. By triggering the shaft rotation only after the vacuum is activated, the physician can avoid agitating the patient's blood (e.g., via shaft rotation) when there is no vacuum to remove the agitated blood.

Although the stylet is not described with reference to the system shown in fig. 19, it should be understood that the stylet may be used with the system, such as by being included within a shaft assembly and coupled to a drive unit 2250. The user may then selectively rotate the shaft 2260 and/or stylet.

Fig. 18A and 18B are perspective views of a handle assembly 1800 and a drive unit 1810 including a shaft 1820 according to an embodiment. Fig. 18A shows the handle assembly 1800 separated from the drive unit 1810, and fig. 18B shows the drive unit 1810 coupled to the handle assembly 1800 with the shaft 1820 inserted into the handle assembly 1800. The handle assembly 1800 and drive unit 1810 may be similar in structure and/or function to other handle assemblies and drive units described herein, and in particular to those depicted in fig. 17A-17D. Accordingly, certain details of such components are not provided herein. 18A-18B, the handle assembly 1800 may then be designed to be ergonomic, for example, to achieve single handle operation. For example, the handle assembly 1800 with its adjustment mechanisms (e.g., first and second adjustment mechanisms, such as the adjustment mechanisms described with reference to fig. 17A-17D) can be designed to operate using a single hand while controlling distal tip advancement, configuration, and orientation.

Fig. 20A and 20B depict another example of a proximal end of a thrombectomy system according to an embodiment. Fig. 20A is a side view of the handle assembly 2300 coupled to a drive unit 2310 and a vacuum source 2330. Fig. 20B is a side view of handle assembly 2300 coupled to vacuum source 2330 and not yet coupled to drive unit 2310 such that shaft 2320 may be partially seen. The handle assembly 2300 and the drive unit 2310 may be similar in structure and/or function to other handle assemblies and drive units described herein, and in particular to those depicted in fig. 19. Accordingly, certain details of such components are not provided herein.

Visualization features

In some variations, the aspiration catheter may include a metal-based radiopaque marker including one or more of a ring, band, coating, plating, and ink (e.g., platinum-iridium, gold, nitinol, palladium) configured to allow fluoroscopic visualization.

The aspiration catheters described herein may comprise any radiopaque metal, such as tungsten, platinum iridium, stainless steel, titanium, and tungsten filled polymers, zirconia ceramics, or any suitable radiopaque material. The visualization feature may be located at any suitable location on or within the catheter (e.g., one or more outer surfaces of the device, inside the catheter, etc.). In some variations, one or more portions of the aspiration catheter may be made of a radiopaque material, or the visualization feature may be attached to the device by any suitable method, such as by mechanical attachment (e.g., embedded in a portion of the catheter, circumferentially surrounding, etc.), adhesive bonding, welding, brazing, combinations thereof, and the like. In some embodiments, the nitinol tube used to form the distal expandable tip and the adjacent curved section may be gold plated for enhanced fluoroscopic visualization.

II method

Also described herein are methods for removing obstructive material (e.g., thrombus) within the vasculature using the systems and devices described herein. In particular, the systems and devices described herein may be configured to navigate the vasculature and remove thrombus. Methods of using such systems and devices may include, for example, advancing an aspiration catheter to a target site in a subject, activating a drive system configured to rotate one or more of a shaft and a stylet, activating a vacuum source to aspirate through the aspiration catheter, aspirating thrombus at the target site into the aspiration catheter, and removing the aspiration catheter and thrombus from the subject.

Fig. 22A is a flow chart of a method 1902 for performing a thrombectomy, for example, using an aspiration catheter separate from a handle assembly and a shaft assembly of the thrombectomy system. The method 1902 may optionally include navigating a guidewire (and/or microcatheter) to a target site (e.g., a thrombus site) at 1912. In some embodiments, the target site may be disposed within the pulmonary vasculature.

At 1914, an aspiration catheter (e.g., catheter 114, 214, etc.) may be advanced over the guidewire (and/or microcatheter) toward the target site. In some embodiments, an aspiration catheter disposed within a cannula may be advanced over a guidewire toward a target site without the need for a advancement shaft. In some embodiments, the cannula, catheter, and shaft may be advanced together into the vasculature toward the target site. In some embodiments, the distal end of the aspiration catheter may be positioned relative to the target site by rotating a cannula as described herein, wherein the cannula has, for example, a bend or curve. Advancement of the suction catheter may be controlled at the handle assembly.

At 1918, if the aspiration catheter is located at the target site (e.g., the distal end of the catheter is proximal to an occlusion substance or thrombus), the aspiration catheter may be deployed. For example, the distal end (e.g., an expandable tip) of the aspiration catheter may be advanced beyond the distal end of the cannula such that the distal end of the aspiration catheter transitions from a retracted configuration to an expanded configuration. Additionally or alternatively, the cannula may be withdrawn relative to the aspiration catheter such that the distal end of the aspiration catheter is distal to the distal end of the cannula. In some embodiments, the guidewire (and/or microcatheter) may be withdrawn from the body. In some embodiments, the distal end of the aspiration catheter may be positioned relative to the target site by rotating the aspiration catheter as described herein, wherein the distal portion of the aspiration catheter has, for example, a bend or curve. Deployment of the suction catheter may be controlled at the handle assembly.

A shaft (e.g., shaft 112, 212, etc.) and/or an optional stylet (e.g., stylet 216, etc.) as described herein may be advanced through the aspiration catheter toward the target site at 1920. In some embodiments, the proximal end of the shaft and optionally the stylet may be coupled to a drive unit, as described herein. As the shaft and optional stylet are advanced toward the distal end of the aspiration catheter, the shaft and optional stylet may be advanced via rotation (e.g., slow rotation) in order to facilitate passage toward the distal end of the aspiration catheter. For example, the shaft and optionally the stylet may be slowly rotated from a distance of about 20cm or less (or about 10cm or less) from the distal end of the aspiration catheter.

At 1922, the shaft and optional stylet may be advanced until it is positioned a preset distance proximal to the distal end of the aspiration catheter, e.g., about 1mm, about 5mm, about 1cm, about 2cm, including all values and ranges therebetween. The drive unit may be locked to the suction catheter. One or more adjustment mechanisms (e.g., adjustment mechanism 134) may be used to fine tune or fine tune the shaft and/or stylet to a preset position proximal to the distal end of the aspiration catheter (e.g., within the expandable tip). The advancement and positioning of the shaft and optional stylet may be controlled at the handle assembly and/or the drive unit.

In some embodiments, the catheter assembly may be configured to be tracked over a guidewire or stylet. In some embodiments, the shaft and optional stylet may define a lumen (not shown). For example, the guidewire may be slidably disposed within the shaft lumen or stylet lumen. In some embodiments, the shaft and optional stylet may be advanced together over the guidewire toward the thrombus site, while in other embodiments, one of the shaft and optional stylet may be advanced first toward the thrombus site (e.g., shaft 212), and the other of the shaft and optional stylet (e.g., stylet 216) may be advanced subsequently into position. Alternatively, at any time during or after insertion of the shaft and optional stylet, the drive system and shaft with optional stylet may be removed from the aspiration catheter for cleaning and subsequently reinserted to continue the thrombectomy procedure. Further optionally, the length of the shaft and optional stylet may be substantially equal to the aspiration catheter such that a drive system coupled to the shaft and optional stylet rotates the shaft and optional stylet within the aspiration catheter (e.g., the expandable tip) at the same longitudinal position of the aspiration catheter.

At 1924, a vacuum source may be activated to aspirate thrombus through the aspiration catheter. For example, at 1926, the vacuum source may generate sufficient negative pressure to draw one or more of the thrombus and/or fluid into the distal end of the catheter, and in combination with movement of the shaft and stylet, may move the thrombus proximally within the lumen of the aspiration catheter. As described herein, activation of negative suction may be controlled at the handle assembly. The amount of negative suction can be controlled. In some embodiments, aspiration (e.g., vacuum pressure) may be delivered in a dynamic manner with a magnitude of about-100 kPa to about-5 kPa on a gauge scale and varying the pressure at different frequencies of about 0.5Hz to about 1000 Hz. In some embodiments, the vacuum pressure may be constant.

At 1926, the drive system may be activated to independently rotate one or more of the shaft and stylet. For example, rotation of the shaft and stylet may be activated (e.g., via a switch on the handle) at the same time (or shortly before or after) the vacuum source is activated. One or more of the speed and direction of axial rotation of the shaft and stylet may be controlled. Axial rotation of the stylet may cause orbital movement of the shaft within the catheter, as described above. At 1926, rotation of the shaft and stylet may cause the shaft to have axial rotation and orbital motion, which may result in a desired interaction with the thrombus to remove it from the vasculature (e.g., by compressing the thrombus, wiping the thrombus off the inner diameter of the aspiration catheter, or twisting the thrombus to remodel/elongate the thrombus). In some embodiments, rotation of one or more of the shaft and stylet may depend on activation of negative aspiration. For example, rotation of one or more of the shaft and stylet may only occur when negative suction is applied through the suction catheter.

In some embodiments, the thrombus may be aspirated into the lumen of the aspiration catheter and mechanically interact with a shaft disposed within the lumen of the catheter. For example, orbital movement of the shaft may separate the clot from the inner circumference of the catheter, thereby reducing stiction and helping the thrombus translate proximally through the aspiration catheter via negative pressure. The physician may monitor patient flow in the aspiration catheter and/or wait a predetermined period of time after activating rotation of the shaft and/or stylet to determine if the thrombectomy is complete. Once the thrombectomy is completed, the shaft assembly and/or aspiration catheter may be removed (e.g., withdrawn) from the patient. In some embodiments, a physician may manually pulse one or more of negative pressure and rotation using a handle assembly as described herein. Manual control of vacuum pressure facilitates accurate control of aspiration and may reduce peri-operative blood loss relative to a constant negative pressure applied in the lumen of the aspiration catheter.

At 1928, a determination may be performed as to whether the procedure is complete. For example, if the thrombus is removed, the physician may determine that the procedure is complete. At 1932, the catheter, shaft, and/or stylet can be removed. Negative suction may also be disabled. If the procedure is not complete (e.g., thrombus removal is not satisfactory), at least the distal end of the aspiration catheter and/or cannula may be adjusted at 1930. For example, the distal end of the catheter may be rotated about the circumference of the blood vessel to reorient the expandable tip of the catheter to ensure thrombus removal (e.g., via a catheter adjustment mechanism). The process may then return to activating the vacuum source at 1924 and/or activating the drive system at 1926.

In some embodiments, the aspiration catheter and/or the target site may be indirectly visualized to determine if further repositioning of the aspiration catheter is required. Such visualization may be accomplished using one or more visualization techniques and visualization features incorporated within the aspiration catheter. For example, visualization features and techniques may facilitate one or more of imaging, positioning, alignment, and manipulation of aspiration catheters in vessels. For example, indirect visualization techniques may include, but are not limited to, ultrasound, fluoroscopy, and X-ray. Contrast agents may be used to visualize the aspiration catheter relative to tissue, such as thrombosis. For example, contrast agent (e.g., contrast medium) may be output through the aspiration catheter. The aspiration catheter may be indirectly visualized as needed throughout the thrombectomy procedure.

Fig. 22B is a flow chart of another method 1904 for performing a thrombectomy using a thrombectomy system, wherein the aspiration catheter and handle assembly are integrated with a drive unit for a control shaft assembly. The method 1904 may optionally include navigating a guidewire (and/or microcatheter) and/or access sheath (or access catheter) to a target site (e.g., a thrombus site) at 1942.

At 1944, an aspiration catheter (e.g., catheters 114, 214, etc.) and a shaft assembly (e.g., comprising a shaft and/or stylet) may be advanced over the guidewire or within the access sheath toward the target site. For example, the catheter assembly and shaft assembly may be advanced together over a guidewire (e.g., as a "double guidewire") into the vasculature toward a target site. That is, during advancement, the shaft and guidewire (and/or microcatheter) may be side-by-side in the aspiration catheter. The guidewire (and/or microcatheter) may then be withdrawn from the body. Alternatively, the catheter assembly and the shaft assembly may be advanced together into the vasculature within an access catheter (e.g., a cannula) that has been positioned with its distal end near or sufficiently near the thrombus site. In some embodiments, the distal end of the aspiration catheter may be positioned relative to the target site by rotating a cannula as described herein, wherein the cannula has, for example, a bend or curve. Advancement of the suction catheter may be controlled at the handle assembly.

At 1946, if the aspiration catheter is located at a target site (e.g., the distal end of the catheter is near an obstructive material or thrombus), the aspiration catheter may be deployed. For example, a distal end (e.g., an expandable tip) of the aspiration catheter may be advanced beyond the distal end of the cannula such that the distal end transitions from a retracted configuration to an expanded configuration. In some embodiments, the distal end of the aspiration catheter may be positioned relative to the target site by rotating the aspiration catheter as described herein, wherein the distal portion of the aspiration catheter has, for example, a bend or curve. Deployment of the suction catheter may be controlled at the handle assembly. In some embodiments, the cannula may be at least partially withdrawn when thrombus formation is removed.

At 1950, a vacuum source can be activated to aspirate thrombus through the aspiration catheter. For example, at 1952, the vacuum source may generate sufficient negative pressure to draw one or more of thrombus and/or fluid into the distal end of the catheter, and in combination with movement of the shaft and stylet, may move the thrombus proximally within the lumen of the aspiration catheter. As described herein, activation of negative suction may be controlled at the handle assembly. The amount of negative suction can be controlled. In some embodiments, aspiration (e.g., vacuum pressure) may be delivered in a dynamic manner with a magnitude of about-100 kPa to about-5 kPa on a gauge scale and varying the pressure at different frequencies of about 0.5Hz to about 1000 Hz. In some embodiments, the vacuum pressure may be constant.

At 1952, the drive system can be activated to independently rotate one or more of the shaft and stylet. For example, rotation of the shaft and stylet may be activated (e.g., via a switch on the handle) at the same time (or shortly before or after) the vacuum source is activated. One or more of the speed and direction of axial rotation of the shaft and stylet may be controlled. Axial rotation of the stylet may cause orbital movement of the shaft within the catheter, as described above. Rotation of the shaft and stylet may cause the shaft to have axial rotation and orbital motion, which may result in a desired interaction with the thrombus to remove it from the vasculature (e.g., by compressing the thrombus, wiping the thrombus from the inner diameter of the aspiration catheter, or twisting the thrombus to remodel/elongate the thrombus).

In some embodiments, the thrombus may be aspirated into the lumen of the aspiration catheter and mechanically interact with a shaft disposed within the lumen of the catheter. For example, orbital movement of the shaft may separate the clot from the inner circumference of the catheter, thereby reducing stiction and helping the thrombus translate proximally through the aspiration catheter via negative pressure. In some embodiments, rotation of one or more of the shaft and stylet may depend on activation of negative aspiration. For example, rotation of one or more of the shaft and stylet may only occur when negative suction is applied through the suction catheter.

At 1954, a determination of whether the procedure is complete may be performed. For example, if the thrombus is removed, the physician may determine that the procedure is complete. At 1958, the catheter, shaft, and/or stylet can be removed (e.g., withdrawn) from the patient. Negative suction may also be disabled. If the procedure is not complete (e.g., thrombus removal is not satisfactory), at least the distal end of the aspiration catheter may be adjusted at 1956. For example, the distal end of the aspiration catheter may be rotated about the circumference of the blood vessel to reorient the expandable tip of the catheter to ensure thrombus removal (e.g., via a catheter adjustment mechanism). The process may then return to activating the vacuum source at 1950.

Fig. 23A-23E are cross-sectional side views of a method of performing a thrombectomy procedure, depicting clot engagement, ingestion, maceration, and transport. Fig. 23A depicts a distal end 2022 (e.g., an expandable tip) of a catheter 2020 deployed from a cannula 2010 at 2000. Shaft 2030 may be disposed within a lumen of distal end 2022. Shaft 2030 may have a curved distal end. The distal end 2022 of the catheter 2020 may be positioned adjacent to the clot 2050 for removal.

Fig. 23B depicts the shaft 2030 rotated to draw clot 2050 into the distal end 2022 of the catheter 2020. In some embodiments, the shaft 2030 may be rotatable so as to remain in contact with or a predetermined distance from an inner wall of the distal end 2022. Negative pressure may also be applied simultaneously through the lumen to further draw clot 2050 into catheter 2020.

Fig. 23C depicts clot 2050 being aspirated and remodeled by distal end 2022 and shaft 2030 of catheter 2020. For example, clot 2050 may be elongated as it is further drawn into catheter 2020. The larger diameter of distal end 2022 relative to catheter 2020 may enable greater clot engaging force under standard vacuum pressure, thereby better ensuring that the clot will be well engaged and less likely to be dislodged.

Fig. 23D depicts the impregnation of clot 2050 by axial and orbital rotational forces applied by shaft 2030. For example, clot 2050 may be broken down into separate portions 2052 sized for withdrawal from the body via catheter 2020. The interaction of the clot with the rail shaft at least at the location where the inner lumen diameter is reduced would otherwise prevent the clot from translating by the vacuum alone. Clot infusion (e.g., separation) via shaft 2030 facilitates advancement of fragmented or minimized clot portions 2052 through catheter 2020 without clogging or occlusion formation. Conventional aspiration catheters often lose suction when large clots clog the catheter lumen.

In some embodiments, the catheter 2020, including the impregnated clot 2052, may be withdrawn into the cannula 2010, which may transition the distal end 2022 from the expanded configuration to the retracted configuration. As the distal end 2020 is withdrawn and collapsed into the sleeve 2010, the distal end 2020 may compress around the clot 2050 and further ensure removal of the clot withdrawn from the patient.

Fig. 23E depicts translation of shaft 2030 a first distance 2042 through distal end 2022 of catheter 2020. In some embodiments, the distal end of the shaft 2030 may be positioned at a second distance 2044 away from the distal end of the catheter 2020.

Although various inventive embodiments have been described and illustrated herein, a person of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto; embodiments of the invention may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. Furthermore, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.

Furthermore, various inventive concepts may be embodied as one or more methods of which examples have been provided. Acts performed as part of the method may be ordered in any suitable manner. Thus, embodiments may be constructed in which acts are performed in a different order than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in the illustrative embodiments.

As used herein, the term "about" and/or "approximately" when used in connection with a number and/or range generally refers to those numbers and/or ranges that are approximately the recited number and/or range. In some cases, the terms "about" and "approximately" may mean within ±10% of the stated value. For example, in some cases, "about 100[ units ]" may mean within + -10% of 100 (e.g., 90 to 110). The terms "about" and "approximately" may be used interchangeably.

Any and all references to publications or other documents, including but not limited to patents, patent applications, articles, web pages, books, and the like, presented anywhere in this application are incorporated herein by reference in their entirety. Furthermore, all definitions as defined and used herein should be understood to have precedence over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

The specific examples and descriptions herein are exemplary in nature and embodiments may be developed by those skilled in the art based on the materials taught herein without departing from the scope of the present invention.

Claims

1. An apparatus, comprising:

a cannula defining a first lumen; and

an aspiration catheter defining a second lumen, the aspiration catheter slidably disposed within the first lumen, the aspiration catheter comprising:

a proximal end coupleable to a vacuum source configured to apply vacuum pressure within the second lumen to draw thrombus from a vessel into the second lumen; and

an expandable tip configured to transition between a retracted configuration in which the expandable tip is constrained within the cannula and an expanded configuration in which at least a portion of the expandable tip is disposed distal of the cannula,

the expandable tip in the expanded configuration has a funnel-shaped profile with a diameter that gradually increases from a proximal end of the expandable tip to a distal end of the expandable tip,

the expandable end in the expanded configuration having a clamping strength of about 0.4lb to about 3lb when disposed within the vessel such that the expandable end in the expanded configuration is configured to withstand collapse due to a pressure gradient within the expandable end resulting from the vacuum pressure acting on the thrombus within the expandable end,

The expandable end in the expanded configuration is further configured to retract into the cannula in response to a retraction force of about 0.5lbs to about 4.0 lbs.

2. The apparatus of claim 1, wherein the expandable distal tip comprises a metal frame and a coating disposed on the metal frame.

3. The apparatus of claim 2, wherein the metal frame defines a plurality of openings, and the coating is an inner layer and an outer layer connected to each other at the plurality of openings.

4. The apparatus of claim 3, wherein each aperture of the plurality of apertures has at least about 0.5mm ² Such that the inner layer and the outer layer of the coating are connectable to each other at each aperture.

5. The apparatus of claim 1, wherein the expandable distal tip comprises a metal frame defining a plurality of openings that increase in size from the proximal end to the distal end of the expandable tip.

6. The apparatus of claim 5, wherein the metal frame further comprises an atraumatic wave ring at the distal end of the expandable tip.

7. The apparatus of claim 5, wherein an aperture of the plurality of apertures disposed at the proximal end of the expandable tip has a length of at least about 2mm and an aperture of the plurality of apertures disposed at the distal end of the expandable tip has a length of less than about 5mm when the expandable tip is in the retracted configuration.

8. The apparatus of claim 5, wherein an aperture of the plurality of apertures disposed at the proximal end of the expandable tip has a proximal angle of at least about-10 ° and an aperture of the plurality of apertures disposed at the distal end of the expandable tip has a proximal angle of less than about 40 ° when the expandable tip is in the expanded configuration.

9. The apparatus of claim 1, wherein the aspiration catheter defines at least one opening disposed near the proximal end of the expandable tip, the at least one opening configured to increase fluid available for mixing with the thrombus to improve flow of the thrombus proximally through the second lumen.

10. The apparatus of claim 1, further comprising:

a flexible shaft having a distal end disposable within the expandable tip of the aspiration catheter,

the distal end of the flexible shaft is configured to rotate within the expandable tip or within 1cm of a proximal end of the expandable tip when the expandable tip is in the expanded configuration to engage and disrupt a portion of the thrombus disposed within the expandable tip.

11. An apparatus, comprising:

a cannula defining a first lumen; and

an aspiration catheter defining a second lumen, the aspiration catheter comprising:

a proximal end coupleable to a vacuum source configured to apply vacuum pressure within the second lumen to draw thrombus from a vessel into the second lumen;

an expandable tip positionable within the vessel, the expandable tip being configured to transition between a retracted configuration in which the expandable tip is constrained within the cannula and an expanded configuration in which at least a portion of the expandable tip is disposed distally of the cannula,

the expandable tip in the expanded configuration has a funnel-shaped profile with a diameter that gradually increases from a proximal end of the expandable tip to a distal end of the expandable tip; and

an elongate body extending between the proximal end of the suction catheter and the proximal end of the expandable tip, the elongate body having a linear proximal section and a flexible curved section disposed adjacent the expandable tip,

at least one of the elongate body and the cannula is configured to translate relative to the other of the elongate body and the cannula to selectively control the exposure of the expandable tip and memory-set bending section outside the cannula to vary the degree of bending of the memory-set bending section and the position of the expandable tip within the vessel.

12. The apparatus of claim 11, wherein the elongate body is further configured to rotate within the first lumen to change the position of the expandable tip within the vessel.

13. The apparatus of claim 11, wherein the memory setting bend section is configured to have a radius of curvature of about 10mm to about 40mm when extending at least partially from the distal end of the cannula.

14. The apparatus of claim 11, wherein the cannula has a curved section.

15. The apparatus of claim 14, wherein the elongate body is further configured to rotate within the first lumen to change a relative orientation of the memory-set bending section relative to the bending section of the cannula such that a total radius of curvature of the aspiration catheter can be adjusted.

16. The apparatus of claim 11, wherein the expandable distal tip comprises a metal frame and a coating disposed on the metal frame.

17. The apparatus of claim 11, wherein the expandable distal tip comprises a metal frame defining a plurality of openings that increase in size from the proximal end to the distal end of the expandable tip.

18. The apparatus of claim 17, wherein the metal frame further comprises an atraumatic wave ring at the distal end of the expandable tip.

19. The apparatus of claim 17, wherein when the expandable tip is in the retracted configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip has a length of about 0.5mm to about 3mm and an aperture of the plurality of apertures disposed at the distal end of the expandable tip has a length of about 3mm to about 10 mm.

20. The apparatus of claim 17, wherein when the expandable tip is in the expanded configuration, an aperture of the plurality of apertures disposed at the proximal end of the expandable tip has a proximal angle of about-10 ° to about 0 °, and an aperture of the plurality of apertures disposed at the distal end of the expandable tip has a proximal angle of about 20 ° to about 40 °.

21. The apparatus of claim 11, further comprising:

The distal end of the flexible shaft is configured to rotate within the expandable tip when the expandable tip is in the expanded configuration to engage and disrupt a portion of the thrombus disposed within the expandable tip.

22. A system, comprising:

an aspiration catheter defining a lumen, the aspiration catheter comprising:

a proximal end coupleable to a vacuum source configured to apply vacuum pressure within the lumen to draw thrombus from a vessel into the lumen;

an expandable tip configured to transition between a retracted configuration in which the expandable tip is constrained within an outer cannula and an expanded configuration in which at least a portion of the expandable tip is disposed distally of the outer cannula,

a flexible shaft positionable within the lumen of the aspiration catheter, the flexible shaft configured to extend from the proximal end of the aspiration catheter to the expandable tip such that a distal end of the flexible shaft is disposed within or 1cm of a proximal end of the expandable tip,

The distal end of the flexible shaft has a non-linear configuration and is configured to rotate within the expandable tip when the expandable tip is in the expanded configuration to engage and disrupt a portion of the thrombus disposed within the expandable tip.

23. The system of claim 22, further comprising:

a handle assembly coupled to a proximal end of the suction catheter, the handle assembly including at least one actuator configured to rotate or translate the suction catheter.

24. The system of claim 23, further comprising:

a drive system coupled to a proximal end of the flexible shaft and configured to rotate the flexible shaft,

the drive system can be releasably coupled to the handle assembly.

25. The system of claim 24, further comprising:

an activation element configured to activate the vacuum pressure and activate the drive system to rotate the flexible shaft.

26. The system of claim 25, wherein the activation element is a button configured to (1) activate the vacuum pressure in response to being pressed a first amount, and (2) activate the drive system in response to being pressed a second amount that is greater than the first amount.

27. The system of claim 22, further comprising the outer sleeve,

the outer sleeve and the aspiration lumen define an annular space configured to deliver fluid into a region proximate the thrombus.

28. The system of claim 27, further comprising a handle assembly coupled to the proximal end of the suction catheter and the proximal end of the cannula, the handle assembly comprising:

a first actuator configured to rotate the aspiration catheter; and

a second actuator configured to translate at least one of the cannula or the aspiration catheter relative to the other of the cannula or the aspiration catheter.

29. An apparatus, comprising:

a flexible shaft positionable within a lumen of an aspiration catheter positionable within a vessel adjacent to a thrombus;

a stylet positionable within a lumen of the flexible shaft, the stylet comprising a shaped distal end having a bending stiffness greater than at least a portion of the flexible shaft such that the shaped distal end can impart a shape to the flexible shaft when disposed within the lumen of the flexible shaft; and

A drive system coupleable to the flexible shaft and the stylet, the drive system configured to rotate the flexible shaft and the stylet such that a distal end of the flexible shaft is capable of remodelling the thrombus to enable the thrombus to be inhaled proximally within the lumen of the aspiration catheter.

30. The apparatus of claim 29, wherein the drive system is configured to independently rotate the flexible shaft and the stylet such that the flexible shaft is rotatable at a first speed and the stylet is rotatable at a second speed different from the first speed.

31. The apparatus of claim 29, wherein the drive system comprises a first motor coupled to the flexible shaft and a second motor coupled to the stylet.

32. The apparatus of claim 29, wherein the flexible shaft is configured to orbitally rotate about a longitudinal axis of the aspiration catheter in response to rotation of the stylet by the drive system when the shaped distal end of the stylet is disposed in the flexible shaft.

33. The apparatus of claim 29, wherein the stylet is configured to rotate about a longitudinal axis of the flexible shaft.

34. The apparatus of claim 29, wherein the distal end of the flexible shaft is a closed distal end such that the stylet cannot extend distally to the distal end of the flexible shaft.

35. The apparatus of claim 29, wherein the distal end of the flexible shaft comprises a bore configured to slidably receive a guidewire.

36. The apparatus of claim 35, wherein the stylet further comprises a lumen configured to receive the guidewire.

37. The apparatus of claim 35, wherein the stylet is removable from the lumen of the flexible shaft such that the lumen of the flexible shaft is receptive to the guidewire.

38. The apparatus of claim 29, further comprising a handle assembly configured to house the drive system.

39. The apparatus of claim 38, wherein the handle assembly comprises one or more seals configured to prevent leakage of vacuum pressure applied within the lumen of the aspiration catheter.

40. The apparatus of claim 38, wherein the handle assembly comprises one or more actuation elements configured to be manipulated by a user to control the drive system to rotate the flexible shaft and the stylet.

41. A method, the method comprising:

navigating a distal end of the aspiration catheter within the vessel to a site including a thrombus;

navigating a distal end of a flexible shaft and a stylet through a lumen of the aspiration catheter, the stylet including at least a portion disposable within the lumen of the flexible shaft;

positioning the distal end of the flexible shaft proximal to the distal end of the aspiration catheter;

applying vacuum pressure to the lumen of the aspiration catheter; and

the flexible shaft and the stylet are rotated using a drive system to remodel the thrombus and draw the thrombus proximally into the lumen of the aspiration catheter.

42. The method of claim 41, wherein rotating the flexible shaft and the stylet comprises rotating the flexible shaft using a first drive mechanism of the drive system and rotating the stylet using a second drive mechanism of the drive system.

43. The method of claim 42, wherein rotation of the stylet using the second drive mechanism is independent of rotation of the flexible shaft using the first drive mechanism such that the stylet and the flexible shaft can rotate at different speeds.

44. The method of claim 41, wherein applying vacuum pressure to the lumen of the aspiration catheter is initiated prior to rotating the flexible shaft and the stylet.

45. The method of claim 41, wherein a distal end of the flexible shaft and the stylet are navigated to the site after the distal end of the aspiration catheter has been navigated to the site.