Aspiration catheter, system, and method

Abstract

To provide a catheter.SOLUTION: A catheter includes a distal tip section disposed on or adjacently to the distal end of the catheter, the distal tip section being invertible about a transition between a catheter body and the distal tip section between a first configuration and a second configuration. Retracting the distal tip section causes the distal tip section to invert about the transition from the first to the second configuration, the second configuration comprising an expansile tip with an open funnel-like distal mouth having a larger diameter than the diameter of the transition.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 941,414, filed November 27, 2019, the contents of which are incorporated herein by reference in their entirety.

[0002] FIELD OF THEINVENTION FIELD OF THE DISCLOSURE The present disclosure relates generally to devices and methods for removing an acute occlusion from a blood vessel during an intravascular medical procedure, and more particularly, to an aspiration catheter. [Background technology]

[0003] Clot retrieval catheters and devices are often used for mechanical thrombectomy for endovascular interventions when patients suffer from conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). Access to neurovascular beds is particularly challenging with conventional techniques because the target vessels are small in diameter, remote to the insertion site, and highly tortuous. Conventional devices are often either too large in profile and lack the deliverability and flexibility required to navigate tortuous vessels, or are ineffective at removing clots when delivered to the target site.

[0004] The clot itself can complicate the procedure by adopting a number of complex forms and consistencies, ranging from simple tubular structures that adopt the shape of a blood vessel to long strand-like arrangements that can span multiple blood vessels at once. The age of the clot can also affect its extensibility, with older clots tending to be less compressible than fresh clots. Experience has also demonstrated that the mechanical properties of the clot can be influenced in significant ways, depending on the nature of the interaction with the clot retrieval device. Furthermore, several mechanisms serve to strongly attach the clot to the vessel wall. Breaking these bonds without damaging the fragile neurovascular vessels is a significant challenge.

[0005] Effective device delivery to the small and highly branched cerebral arterial system remains challenging, and conventional clot retrieval catheters suffer from a number of shortcomings. First, the diameter of the catheter itself must be small enough to avoid causing significant discomfort to the patient. The retrieval catheter must also be flexible enough to navigate the vasculature and withstand high strains while also possessing axial stiffness to provide smooth advancement along the pathway. Once at the target site, typical objects retrieved from the body are substantially larger in size than the tip of the catheter, making retrieval of the object into the tip more difficult. For example, tough fibrin-rich clots can often be difficult to extract because they can become lodged in the tip of a conventional fixed-port catheter. In addition, this lodging can cause the soft portion of the clot to be sheared off from the tough region.

[0006] Small diameters and fixed tip sizes are also inefficient in inducing the suction required for the removal of blood and thrombus material during the procedure. The suction must be strong enough so that any debris that may result from the use of suction or mechanical thrombus removal devices can be held stationary so that it does not migrate and occlude the distal vessel. However, when aspirating with a conventional fixed port catheter, a significant portion of the aspirate flow will come from the vascular fluid proximal to the tip of the catheter where no clot is present. This significantly reduces the efficiency of aspiration and reduces the success rate of clot removal. Summary of the Invention [Problem to be solved by the invention]

[0007] Any catheter design attempting to overcome these challenges using an expanding distal tip or structure would need to be strong enough to grip the clot and apply a consistent radial force in the expanded state, and the structure would also need to be sufficiently flexible and resilient when in the collapsed state to withstand the severe mechanical strains imposed when navigating tortuous vasculature.

[0008] The present solution solves these and other problems in the art. [Means for solving the problem]

[0009] It is an object of the present invention to design to provide a system, device, and method that meets the above-mentioned needs. Thus, it is desirable for an aspiration clot retrieval catheter to have a port facing the thrombus for efficient aspiration and easy retrieval of the clot, while having a collapsed state that is low profile and sufficiently flexible in multiple directions for deliverability to the target site. The body of the catheter can also incorporate deliverability improvements over existing designs for ease of operation.

[0010] In some embodiments, an aspiration catheter is disclosed that includes a catheter body having a proximal end and a distal end. A distal tip section can be disposed at or adjacent to the distal end, the distal tip section being flippable about a transition between the catheter body and the distal tip section between a first configuration and a second configuration. Retracting the distal tip section flips the distal tip section about the transition from the first configuration to the second configuration, the second configuration comprising an expandable tip having an open funnel-like distal mouth having a diameter larger than the diameter of the transition.

[0011] In some embodiments, the distal tip section has a folded configuration inside the guide catheter.

[0012] In some embodiments, the first configuration and the second configuration are part of an expanded configuration of a distal tip section distal to the guide catheter or sheath.

[0013] In some embodiments, the distal tip section comprises a mushroom-shaped section configured to be inverted into the second configuration to form an open, funnel-like distal mouth.

[0014] In some embodiments, the distal tip section is shaped and configured to reduce clot shear in the first configuration.

[0015] In some embodiments, the distal tip section includes a plurality of sealing members configured to be inverted from a mushroom-shaped section in a first configuration to an open, funnel-like distal mouth in a second configuration.

[0016] In some embodiments, each sealing member comprises a hemispherical shape in the first configuration and in the second configuration, the hemispherical shapes being substantially opposing mirror images of one another between the first configuration and the second configuration.

[0017] In some embodiments, each sealing member corresponds to a separate funnel port in the second configuration.

[0018] In some embodiments, each sealing member corresponds to multiple sealing layers with a corresponding vessel wall.

[0019] In some embodiments, each sealing member is reversible for its corresponding transition portion.

[0020] In some embodiments, each sealing member is selectively spaced along the catheter body. In some embodiments, the sealing members are evenly spaced. In some embodiments, the sealing members are gradually spaced closer or further apart from one another. In some embodiments, the sealing members are aligned along a common longitudinal axis.

[0021] In some embodiments, the distal tip section comprises a proximal portion and a distal portion, the distal portion having a diameter smaller than the diameter of the proximal portion. The diameter of the proximal portion can be at least twice the diameter of the distal portion. The distal portion can have an open, atraumatic end in continuity with the inner lumen of the catheter body. The outer surface of the distal tip section, which can be between the proximal and distal portions, can be curved or otherwise contoured.

[0022] In some embodiments, the open funnel-like distal port is collapsible during or after a procedure to reduce or eliminate flow restriction within the vessel.

[0023] In some embodiments, a method of aspirating an occlusive thrombus from a blood vessel is disclosed, the method can include moving a distal tip section of the aspiration catheter from a collapsed configuration to a first expanded configuration by translating the aspiration catheter at least partially distal to a sheath or delivery catheter, and retracting the distal tip section to invert the distal tip section to a second expanded configuration about a transition between the distal tip section and the catheter body, the second configuration comprising an expandable tip having an open funnel-like distal mouth with a diameter greater than a diameter of the transition.

[0024] In some embodiments, a method includes delivering an aspiration catheter according to the present disclosure to a location of a target within a blood vessel.

[0025] In some embodiments, the method includes aspirating through the distal tip section to encourage the thrombus into an open, funnel-like distal port of the distal tip section.

[0026] In some embodiments, the method includes forming a distal tip section having a mushroom-shaped section configured to be inverted into a second configuration to form an open, funnel-like distal mouth.

[0027] In some embodiments, the method includes shaping the distal tip section to reduce clot shear in the first configuration.

[0028] In some embodiments, the method includes reducing clot shear with the distal tip section in a first configuration.

[0029] In some embodiments, the method includes inverting a plurality of sealing members of the distal tip section from a mushroom-shaped section in a first configuration to an open funnel-like distal mouth in a second configuration.

[0030] In some embodiments, the method includes inverting a sealing member of each of the distal tip sections to form a corresponding funnel-like distal port.

[0031] In some embodiments, each sealing member has a hemispherical shape in the first configuration and in the second configuration, the hemispherical shape being substantially a mirror image of the opposing other between the first configuration and the second configuration.

[0032] In some embodiments, the method includes sealing a plurality of sealing layers with respective sealing layers of respective sealing members to corresponding vessel walls.

[0033] In some embodiments, each sealing member is reversible about each transition.

[0034] In some embodiments, the method includes selectively spacing each sealing member along the catheter body.

[0035] In some embodiments, the method includes collapsing the open funnel-like distal port during the procedure to reduce or eliminate flow restriction within the vessel.

[0036] In some embodiments, the method includes collapsing the open funnel-like distal port after the procedure to reduce or eliminate flow restriction within the vessel.

[0037] Other aspects and features of the present disclosure will become apparent to those of ordinary skill in the art upon consideration of the following detailed description in conjunction with the accompanying figures. [Brief description of the drawings]

[0038] The above and further aspects of the present disclosure are further considered in conjunction with the following description of the accompanying drawings, in which like numerals in various drawings indicate like structural elements and features. The drawings are not necessarily to scale, with emphasis instead being placed on illustrating the principles of the present disclosure. The figures depict one or more implementations of the device of the present invention, merely by way of example and not by way of limitation. It is expected that those skilled in the art can conceive and combine elements from multiple drawings to better meet the needs of the user. [Figure 1A]FIG. 2 is an enlarged view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 1B] FIG. 1B is an enlarged view of the tip section of FIG. 1A in a second configuration. [Figure 2A] FIG. 2 is an enlarged perspective view of the exemplary catheter of FIGS. 1A-1B in a first configuration. [Figure 2B] FIG. 2 is an enlarged cross-sectional perspective view taken along the centerline of the exemplary catheter of FIGS. 1A-1B in a first configuration. [Figure 3A] FIG. 1C is an enlarged cross-sectional perspective view of an alternative to the exemplary catheter of FIGS. 1A-1B in a first configuration taken along the centerline in the first configuration. [Figure 3B] FIG. 3B is an enlarged view of section AA of FIG. 3A. [Figure 4A] FIG. 2 is an enlarged view of another exemplary catheter embodiment of the present disclosure, the distal tip section being in a first configuration. [Figure 4B] FIG. 4B is an enlarged view of the tip section of FIG. 4A in a second configuration. [Diagram 5] FIG. 2 is an enlarged view of another exemplary catheter embodiment of the present disclosure, the distal tip section being in a first configuration. [Figure 6] FIG. 2 is an enlarged view of another exemplary catheter embodiment of the present disclosure, the distal tip section being in a first configuration. [Figure 7A] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 7B] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 7C] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 8A] FIG. 2 is a close-up view of an exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 8B] FIG. 8B is a close-up view of one exemplary shoulder section of section BB of the tip section of FIG. 8A in a second configuration. [Figure 8C]FIG. 8B is a close-up view of one exemplary shoulder section of section BB of the tip section of FIG. 8A in a second configuration. [Figure 8D] FIG. 8B is a close-up view of one exemplary shoulder section of section BB of the tip section of FIG. 8A in a second configuration. [Figure 8E] FIG. 8B is a close-up view of one exemplary shoulder section of section BB of the tip section of FIG. 8A in a second configuration. [Figure 9] FIG. 1 illustrates one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration being delivered to a treatment site within a blood vessel. [Figure 10] FIG. 1 illustrates one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration being delivered to a treatment site within a blood vessel. [Figure 11] FIG. 1 illustrates one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration being delivered to a treatment site within a blood vessel. [Figure 12A] FIG. 1 is a close-up view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration during a clot aspiration procedure within a blood vessel. [Figure 12B] 12B is a close-up view of the tip section of FIG. 12A in a second configuration during a clot aspiration procedure within a blood vessel. [Figure 13] FIG. 1 is a schematic diagram of one exemplary catheter embodiment of the present disclosure, for use with a sheath and a balloon guide catheter, the distal tip section being shown moving between a first configuration and a second configuration. [Figure 14A] FIG. 2 is an enlarged perspective view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration; [Figure 14B] 14B is an enlarged cross-sectional view of the exemplary catheter of FIG. 14A, with the distal tip section in a first configuration. [Figure 14C] 14B is an enlarged cross-sectional view of the exemplary catheter embodiment of FIG. 14A, with the distal tip section in a first configuration. [Figure 15A] FIG. 2 is an enlarged perspective view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration; [Figure 15B] FIG. 15B is a rear perspective view of the exemplary catheter of FIG. 15A, with the distal tip section in a first configuration. [Figure 16A] FIG. 2 is an enlarged perspective view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration; [Figure 16B] FIG. 16B is a rear plan view of the catheter of FIG. 16A, with the distal tip section in a first configuration. [Figure 16C] FIG. 16B is an enlarged cross-sectional view of the catheter of FIG. 16A, with the distal tip section in a first configuration. [Figure 16D] 16B is another enlarged cross-sectional view of the catheter of FIG. 16A, with the distal tip section in a first configuration. [Figure 17A] FIG. 2 is an enlarged perspective view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration; [Figure 17B] FIG. 17B is a rear plan view of the exemplary catheter of FIG. 17A, with the distal tip section in a first configuration. [Figure 17C] 17B is an enlarged cross-sectional view of one exemplary catheter of FIG. 17A, with the distal tip section in a first configuration. [Figure 18A] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 18B] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 19A] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 19B] FIG. 19B is a close-up view of one exemplary shoulder section of the tip section CC of FIG. 19A in a first configuration. [Figure 19C] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 19D] FIG. 19D is a close-up view of one exemplary shoulder section of section DD of the tip section of FIG. 19C in a first configuration. [Figure 20A]FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 20B] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 20C] FIG. 2C is a close-up view of one exemplary shoulder section of tip section EE of FIG. 20B in the first configuration. [Figure 20D] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 20E] FIG. 2E is a close-up view of one exemplary shoulder section of cross section FF of the tip section of FIG. 20D in the first configuration. [Figure 21A] FIG. 2 is an enlarged cross-sectional view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 21B] FIG. 21B is a close-up view of one exemplary shoulder section of section GG of the tip section of FIG. 21A in a first configuration. [Figure 22A] FIG. 2 is an enlarged side view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 22B] FIG. 2 is an enlarged side view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 22C] FIG. 2 is an enlarged side view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 22D] FIG. 2 is an enlarged side view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 22E] FIG. 2 is an enlarged side view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 22F] FIG. 2 is an enlarged side view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 22G] FIG. 2 is an enlarged side view of one exemplary catheter embodiment of the present disclosure, with the distal tip section in a first configuration. [Figure 23] FIG. 1 is a side view of one exemplary catheter embodiment of the present disclosure with the distal tip section in a first configuration and positioned with an exemplary luer. [Figure 24A] FIG. 24 is a side view of the exemplary catheter embodiment of FIG. 23 with the distal tip section in a first configuration and positioned with an exemplary luer. [Figure 24B] FIG. 24 is a side view of the exemplary catheter embodiment of FIG. 23 with the distal tip section in a second configuration and positioned with an exemplary luer. [Figure 25A] FIG. 24B is an enlarged view of section HH of FIG. 24A. [Figure 25B] FIG. 24C is an enlarged view of section II of FIG. 24B. [Figure 26] FIG. 25C is an exploded side view of the exemplary catheter and tip section embodiment of FIGS. 23-25B being push loaded through a taper lock. [Figure 27A] FIG. 27 is an exploded side view of the embodiment of FIG. 26 being push loaded through the taper lock. [Figure 27B] FIG. 27B is a side view of the embodiment of FIG. 27A positioned with a taper lock. [Figure 28A] FIG. 27C is a side view of the embodiment of FIGS. 27A-27B with a loading tool. [Figure 28B] FIG. 28B is a side view of the embodiment of FIG. 28A in a second configuration. [Figure 29A] FIG. 28C is a side view of the embodiment of FIGS. 28A-28B in a third configuration. [Figure 29B] FIG. 28A is a side view of the embodiment of FIGS. 28A-29A in a fourth configuration. [Diagram 30] FIG. 1 is a flow diagram outlining a method of using a system according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Specific embodiments of the present disclosure will now be described in detail with reference to the drawings, where like reference numbers indicate functionally similar or identical elements. The embodiments address many of the deficiencies associated with conventional fixed port catheters, such as limited flexibility and inefficiently induced suction.

[0040] One of the objectives of the solution of the present disclosure is an invertible expandable catheter that can provide both localized flow restriction / stop with a large distal facing mouth and navigate tortuous regions of the vasculature to reach occlusive clots. The flow restriction and large tipped design provide substantially greater aspiration efficiency. Such advantages may also be particularly beneficial in the case of stroke interventional procedures, where the vessels in the neurovascular bed are particularly small and circuitous, so that the tailored axial and bending stiffness profile can prevent tangling and binding. The catheter may also be compatible with a relatively low profile access sheath and outer catheter, so that the puncture wound in the patient's groin (in the case of femoral access) can be easily and reliably closed. The catheter may also feature an internal and / or external low friction liner, as well as an outer polymer jacket or membrane disposed around the support structure.

[0041] Accessing various blood vessels therein, whether coronary, pulmonary, or cerebral, involves well-known procedural steps and the use of numerous conventional, commercially available accessory products. These products, such as angiographic materials, rotating hemostatic valves, and guidewires, are widely used in laboratories and medical procedures. When these products are used with the systems and methods of the present disclosure in the following description, their functions and exact configurations will not be described in detail.

[0042] Referring to the figures, FIG. 1A shows a close-up view of one exemplary embodiment of the present disclosure of an aspiration catheter 101 with the distal tip section 100 in an expanded state in a first configuration. The section 100, including its outer surface, can be self-expanding and made from a framework of columns including Nitinol with interwoven platinum filaments for radiopacity. However, the section 100 is not so limited and can use any material or combination of materials as needed or desired, including being constructed from polymer alone. The section 100 can also feature an internal and / or external low friction liner, as well as an outer polymer jacket or membrane disposed around the support structure. In a first configuration in which the section 100 is distal to an outer catheter and at a treatment site within the vasculature, according to an embodiment of the present disclosure, the section 100 is shown with an exemplary mushroom-shaped section 100.

[0043] In some embodiments, the mushroom-shaped section 100 can include a distal section 105 having a diameter smaller than the diameter of the proximal section 103. In some embodiments, the diameter of section 103 can be twice the diameter of section 105, although the diameter of section 103 can be larger or smaller relative to section 105 as needed or desired. Section 105 can be an open, atraumatic end in continuity with the inner lumen 113 of the catheter 101. The contour of the outer surface of section 100 between section 105 and section 103 can be curved. The material of the proximal section 105 can be tapered.

[0044] In the second configuration of FIG. 1B, it can be seen that the section 100 has been everted about the end 105 (also referred to herein as the "transition" between the catheter body 117 and the section 100), which was previously the distal end, but is now the proximal end of the section 100 in the second configuration. The portion of the catheter 101 proximal to the end 105 (e.g., the catheter body proximal to the section 100) can be more rigid or otherwise stiffer compared to the more elastic section 100, thereby allowing for the inversion between the first and second configurations. In some embodiments, the shape of the first configuration previously shown in FIG. 1A can be inverted to the shape of the second configuration of FIG. 1B by retracting the section 100 within the vessel, switching between tapering radially outward a predetermined distance in the proximal direction, as in FIG. 1A, and tapering radially outward in the distal direction, as in FIG. 1B. In some embodiments, segment 100 is transitioned between the first and second configurations by retracting segment 100 a predetermined distance. Segment 100 in the second configuration can be sized and configured into a funnel-like shape such that when deployed at the target site, segment 100 expands to atraumatically contact the inner vessel wall and provide the largest possible opening for aspirating and receiving clot C.

[0045] The sections on or proximal to section 105 may be more flexible than the sections on or proximal to section 103 to induce self-expansion and / or eversion during delivery and eversion as section 100 forms the predetermined funnel-like shape of the second configuration. By incorporating a funnel shape, the clot may be gradually compressed to a smaller diameter during retrieval so that it may be completely aspirated through the catheter and into an aspiration syringe or canister. If the clot becomes lodged within mouth 114 of section 100, mouth 114 may protect the clot and prevent dislodging of the clot as aspiration suction is maintained and catheter 101 is retracted into the sheath or outer catheter.

[0046] In some embodiments, the catheter 101 and its section 100 can be configured to pass through a sheath or guide having an inner diameter of less than 0.090", more ideally less than 0.087", and most preferably less than 0.085". In some embodiments, the catheter 101 and its section 100 can have a low delivery profile (e.g., about 0.080" or 2 mm) and can further expand its distal port to the size of the vessel in which the clot is located, which may be as large as 5 mm. An ideal section 100 can expand its port 114 to a diameter of at least 3 mm. In some embodiments, the catheter 101 can collapse its port 114 during or after the procedure, thereby reducing or eliminating any flow restriction and allowing blood and / or contrast to reach the distal vasculature.

[0047] The section 100 in the first and / or second configurations can be designed to be approximately equal to or slightly larger than the inner diameter of the corresponding vessel in which the clot is located, depending on the configuration. The section 100 can also include a flexible membrane or cover (e.g., a polymeric membrane disposed therearound and stretched to assume the profile of the distal framework). In some embodiments, the membrane can be a highly elastic material that can expand with the frame to adopt a funnel shape, or can start with an oversized funnel shape and be pleated or pleated or creased to reduce its profile for delivery. The membrane in some embodiments can be bonded to the frame, or wrapped around the frame, or partially pleated over the frame. Suitable membrane materials can include elastic polyurethanes such as clonoprene, ideally with a Shore hardness of 40A or less, or silicone elastomers.

[0048] In some embodiments, segments 100 can begin to expand to a first configuration as portion 105 moves distally and / or out of a corresponding delivery catheter. Segment 100 can then be moved to a second, inverted funnel configuration by actuating segment 100 and inverting portion 105 around portion 103.

[0049] In some embodiments, the section 100 may begin to invert to the second configuration by breaking or snapping the portion 105. The terms "break" and / or "snap" as used herein include regions of the section 100 that facilitate inversion between the first and second configurations and / or avoid kinking. The break may include one or more localized changes in physical properties relative to other regions of the section 100 (e.g., increased flexibility, pre-weakened regions, etc.). In some embodiments, the break associated with the portion 105 may be formed in the framework of the section 100 such that inversion and / or pleating occurs after the catheter 101 is translated or otherwise retracted a predetermined distance. In some embodiments, the break in the portion 105 may include a localized heat treatment such that the region proximal portion 105 is more ductile but prevents kinking. In some embodiments, the section 100 may invert upon contact with the clot C.

[0050] It will also be appreciated that section 100 in the second configuration and / or first configuration may be hemispherical in shape as shown, or may be any other shape, such as ellipsoidal, heart-shaped, oval, cylindrical, hemispherical, or any other funnel-like shape, as needed or desired. For example, section 100 may be shaped like an earbud in the first configuration and a funnel in the second configuration.

[0051] FIG. 2A is an enlarged perspective view catheter 101 of FIGS. 1A-1B in a first configuration. FIG. 2B is an enlarged cross-sectional perspective view taken along the centerline of catheter 101 of FIGS. 1A-1B in a first configuration. As shown, section 100 includes portions 103, 105 having a change in diameter as described above, forming the mushroom shape described above with a lumen 113 extending continuously through catheter 101 including section 100. Section 100 may then be capped with one or more reinforcing shoulder sections 107 proximate section 105. One or more shoulder sections 107 may be thicker or may have a variable thickness (e.g., thinner at or adjacent end 105, but relatively thicker proximal to end 105 where section 100 joins catheter body 117).

[0052] FIG. 3A is an enlarged cross-sectional perspective view of a first configuration alternative catheter 101'. FIG. 3B is an enlarged view of section AA of FIG. 3A. As shown, section 100 can be overlaid with one or more reinforcing shoulder sections 107 adjacent section 105. As shown, section 107 in this illustrated embodiment can taper from a narrower section adjacent section 105 to a thicker section where section 107 joins with body 117'. Body 117', which can include a skived outer jacket herein, can include an inner liner 115. Liner 115 can include a PTFE liner and / or strike layer in some examples. In this regard, the skived outer jacket can be reflowed onto a coil, braid, or laser cut tube support member. A PTFE liner may be bonded over the reflowed section as shown, or a skived outer jacket may be reflowed through the braid, coil, or laser cut tube itself, which can then eliminate the need for an underlying overlapping outer jacket.

[0053] One or more coil members 119 may also be included for desired stiffness and / or bending characteristics of section 100 during use (e.g., aspiration of clot during clot retrieval). Coil members 119 may include the same bending characteristics and may be equally spaced apart. In other embodiments, coil members 119 may include variable bending characteristics and / or spacing between coil members as needed or desired for the treatment site or procedure. A jacket 116 may also be included in communication with coil members 119 and liner 115. For example, coil members 119 may be generally disposed within, nested, embedded, and / or surrounded by jacket 116. In some embodiments, jacket 116 may include a reflowed polymer jacket.

[0054] FIG. 4A shows a close-up view of one exemplary embodiment of the present disclosure of an aspiration catheter 401 with a distal tip section 400 in an expanded state in a first configuration, similar to catheter 101 and section 100 as described above. However, in this example, section 400 includes a double mushroom shape and / or an invertible hemisphere shape in the first configuration, as shown in FIG. 4A, and a double funnel in the second configuration, as shown in FIG. 4B. The double configuration in this example is configured to achieve a multi-sequential layer seal with the corresponding vessel wall. The close-up arrows shown in FIGS. 4A-4B indicate the exemplary aspiration flow direction(s) for each illustrated configuration. In some examples, each illustrated sealing member 432, 434 arranged sequentially can collectively achieve a multi-sequential layer seal. Distal sealing member 432 can include a distal portion 405 and a proximal portion 403, and proximal sealing member 434 can include a distal portion 425 and a proximal portion 423 and a corresponding open end 424. Member 432 may include a diameter that is smaller than the diameter of proximal sealing member 434. However, in both the first and second configurations of Figures 4A-4B, the diameters of portions 403 and 423 of sealing members 432, 434, respectively, are larger than the outer diameter of catheter body 417.

[0055] Sealing members 432, 434 can be configured to flip about portions 405 and 425, respectively, in certain embodiments, substantially simultaneously, sequentially (e.g., member 432 before member 434, or vice versa), or manually by a corresponding actuation system controlled by an operator. In some embodiments, sealing members 432, 434 can be selectively and / or sequentially spaced apart such that they do not overlap when compressed within a guide sheath or delivery catheter for advancement, such that the size of the guide sheath or delivery catheter can be maximized relative to the balloon guide dimensions. Each of members 432, 434 can also be flipped to a second configuration, similar to section 100, as described above.

[0056] 5, similar to Figures 4A-4B, is an expanded view of another exemplary catheter embodiment 501 of the present disclosure, in a first configuration of a distal tip section 500 including a plurality of sealing members 532, 534, 536. As shown, members 532, 534, 536 can include various diameters, with the diameters being largest proximally and gradually varying distally with member 532 having a smallest diameter in both the first and second configurations.

[0057] With the various diameters as shown, the section 500 allows for a wide range of vessel diameters as well as increased redundancy for maintaining a seal with the corresponding vessel. The diameters of the members 532, 534, 536 can be varied as needed or desired. For example, the outer diameter of the member 536 associated with section 533 can be twice the diameter of the member 534 in section 523, which in turn can be twice the diameter of the member 532 in section 503. However, the solution is not so limited and the diameters and / or spacing of the members 532, 534, 536 can be varied as needed or desired. Additionally, while only three members 532, 534, 536 are shown in FIG. 5, fewer or more sealing members are contemplated as needed or desired. Each of the members 532, 534, 536 can also be flipped to a second configuration, similar to the section 100, as shown and described above.

[0058] 6 is a close-up view of another exemplary catheter embodiment 601 of the present disclosure, with distal tip section 600 in a first configuration. As shown, section 600 can include a variety of diameters, with folds or breaks 606 positioned between larger diameter distal section 605 and proximal section 603 to form a continuous partial pearl-shaped section 600. The folds or breaks 606 can allow a single sealing member shape to be used to seal against corresponding vessel walls at a wide range of vessel diameters (rather than a multi-sealing approach as shown in FIGS. 4A-4B or multiple sealing members of various diameters in FIG. 5). The diameters of sections 603, 605 can be varied as needed or desired. Each of sections 603, 605 can also be inverted to a second configuration, similar to section 100, as described above.

[0059] 7A is an enlarged cross-sectional view of one exemplary distal tip section embodiment in a first configuration having one or more longitudinal channels, grooves, ridges, and / or recesses. These features can be configured to shape the illustrated tip section to have its funnel shape in a second configuration during use. The embodiment illustrated in FIG. 7A can also improve radial force, pushability of the corresponding catheter and distal tip section, and can help initiate a particular pleat pattern when retracted through an outer sheath.

[0060] FIG. 7B shows a similar tip section, but with helical (or otherwise twisted) channels, grooves, ridges, and / or recesses. FIG. 7C shows a similar tip section, but with circumferentially ring-shaped channels, grooves, ridges, and / or recesses. It will be understood that any of the illustrated embodiments of FIGS. 7A-7C can be used by themselves or in combination with one or more of the illustrated exemplary channels, grooves, ridges, and / or recesses and other features contemplated for use with catheters and corresponding tip sections of the present disclosure. The sections illustrated in FIGS. 7A-7C can also include a mini-funnel opening at the distal port to reduce clot shear when the sealing member is not everted.

[0061] FIG. 8A is a close-up view of an exemplary catheter embodiment of the present disclosure in which the distal tip section is in a first configuration. FIGS. 8B-8E show close-up views of an exemplary shoulder section at or adjacent to the distal section 805. More specifically, the shoulder section of FIGS. 8B-8E can include a transition section from the substantially elongated catheter body 817 to the section 805. As previously referenced for the catheter 101, this transition can include a bending feature (e.g., a thin area, one or more recesses, one or more folds, one or more breaks, etc.) that reduces the force for flipping from the first configuration to the funnel shape of the second configuration. In other examples, the transition can include one or more reinforcing elements (e.g., ribs, thickened areas such as a reinforced shoulder section, a firmer or stiffer material, etc.). The one or more reinforcing elements can be configured to increase the resilience of the section 800 to collapsing under vacuum. The thickness of section 800 can vary as it tapers radially outward, such that the outermost portion in contact with the vessel wall is ultra-soft and the inner portion closer to the tubular portion is stiffer and resists collapsing under vacuum.

[0062] FIG. 9 illustrates one exemplary catheter 901 embodiment with a tip segment 900 in a first configuration being delivered to a clot C within a blood vessel V. As shown, blood between segment 900 and clot C, indicated by a large arrow within the vessel, flows proximally through catheter 901. The proximal end of catheter 901 may include a port 950 that can be switched open or closed. When open, indicated by a large arrow adjacent port 950, allows trapped fluid between segment 900 and clot C to escape as catheter 901 advances. Otherwise, when closed, segment 900 (and its corresponding sealing member(s)) can act like a piston within blood vessel V, moving clot C distally. In FIG. 9, it is understood that segment 900 can be smaller than the surrounding blood vessel V, allowing blood to flow around segment 900. However, port 950 can be reduced to allow flow around segment 900. Port 950 is advantageous as segment 900 seals off vessel V and advances distally.

[0063] 10 illustrates one exemplary catheter 1000 embodiment with tip section 1001 in a first configuration being delivered to clot C. As shown, between section 1001 and its sealing member and clot C, blood flows proximally between catheter 1000 and vessel V through pores 1060, as indicated by the arrows inside the vessel. When applied, pores 1060 are selectively sized and / or positioned within section 1001 to allow a predetermined percentage of blood to flow proximally as tip section 1001 advances, to have a sufficient predetermined percentage of occlusion to direct suction to clot C, while avoiding pushing clot C distally. Additionally, pores 1060 can close to allow maximum suction when tip section 1001 is inverted to form a funnel in a second configuration.

[0064] FIG. 11 illustrates one exemplary catheter 1100 embodiment with a tip section 1101 in a first configuration being delivered to a clot C. As shown, between the section 1101 and its sealing member and the clot C, blood flows proximally through a one-way valve 1170. The valve 1170 can be formed or otherwise positioned on the catheter 1100 proximal to the section 1101. Although only one valve 1170 is shown in FIG. 11, more valves may be used or included as needed or desired. In some examples, the one or more valves 1170 can be configured to close during aspiration to direct a vacuum at the face of the clot C and to open as the section 1101 is advanced in its first configuration within the vessel V to allow blood to flow into the vessel proximal to the section 1101.

[0065] 12A is a close-up view of one exemplary catheter 1201 embodiment with the distal tip section 1200 in a second configuration during a clot aspiration procedure in a blood vessel V. FIG. 12B is a close-up view section 1200 in a second configuration during a clot aspiration procedure in a blood vessel V. Section 1200 can use its first configuration or both or either of its second configuration as a plunger. In some examples, proximal port 1250 can be open during advancement to the treatment location so as not to disturb clot C. After reaching clot C, port 1250 can be closed to allow tip section 1200 to be advanced and retracted in a repeated motion to remove clot C from blood vessel V and break any adhesion forces before applying suction and / or removing clot C.

[0066] In some embodiments, the tip section 1200 of the catheter 1201 is configured to be retracted a predetermined distance and advanced in a repetitive motion to remove the clot C proximally and distally from the vessel V. In some embodiments, the tip section 1200 of the catheter 1201 is configured to be retracted to invert into the illustrated funnel-like shape of the second configuration to remove the clot C only proximally from the vessel V. In some embodiments, the tip section 1200 of the catheter 1201 is configured to be advanced from the second configuration back to the first configuration to remove the clot C distally from the vessel V.

[0067] 13 is a schematic diagram of another exemplary catheter 1301 of the present disclosure, in which the tip section 1300 is shown in a first configuration and a second configuration (dashed lines) for use with a sheath S and a balloon guide catheter B. As shown, the tip section 1300 can be advanced through an outer balloon B and / or sheath S to reach a treatment site, such as an occlusion in an internal carotid artery (ICA). To minimize the profile, the tip section 1300 can be everted into the second configuration (e.g., a funnel-like shape) and / or wrapped circumferentially prior to insertion into the guide sheath S. As the everted and / or wrapped tip section 1300 exits the guide sheath S in the ICA, the section 1300 can return to its first configuration shape while gripping the vessel wall V and advancing distally to the face of the clot C. The section 1300 in the first configuration can then be slightly retracted and everted into the funnel-like shape of the second configuration prior to aspiration. Alternatively, the tip tubular section 1317 (e.g., the substantially elongated catheter body section discussed above) covered by the tip section 1300 may be compressible such that the tip section 1300 and the tubular 1317 section in the first configuration can be compressed for low-profile advancement through the outer guide sheath S.

[0068] Any of the catheters disclosed herein, including catheter 1301, can also be used with one or more stent retrievers, which may be understood to include features more clearly described in U.S. Patent Application Serial No. 16 / 021,505, as well as U.S. Patent Nos. 10,292,723, 10,299,811, 10,363,054, 8,777,976, 8,852,205, 9,402,707, 9,445,829, and 9,642,639. Any of the catheters disclosed herein can also direct an aspiration vacuum to the clot surface, while the stent retriever can hold the composite clot (composed of friable and fibrin-rich regions) in a manner that prevents embolization and aids in the removal of the clot from the vessel wall. The combined stent retriever retraction and suction through the funnel-like shape of the tip section 1300 in the second configuration can work together to increase the chances of a successful first pass in removing clot C. In some embodiments, the funnel-like shape of the tip section 1300 can reduce shearing of the clot upon entry into the catheter 1301, stop flow and protect the distal vessel from embolization of new areas, and can direct suction vacuum to the clot surface while the stent retriever holds the composite clot (composed of friable and fibrin-rich regions) while preventing embolization and helps slough the clot from the vessel wall.

[0069] FIG. 14A is an enlarged perspective view of one exemplary catheter 1401 embodiment in a first configuration of a distal tip section 1400 having one or more external ribs 1420. As shown, the external ribs 1420 can be positioned radially along the outer surface of the section 1401, one or more axially projecting outward, and can extend between a proximal portion 1403 and a distal portion 1405 of the section 1400. The one or more ribs 1420 can be configured to minimize the volume of material that must be folded to pass through the section 1400 while maintaining structural integrity. FIG. 14B shows a cross-sectional view taken along a portion of the section 1400 between the ribs 1420, and FIG. 14C shows a cross-sectional view of the section 1400 taken along one of the one or more ribs 1420.

[0070] As shown, the ribs 1420 in FIG. 14C include a cross-section that is significantly thicker (e.g., at least twice as thicker) than the non-ribbed portions of section 1400. In some embodiments, the ribs 1420 can include a maximum width at or adjacent portion 1403 and taper therefrom to a smaller width toward portion 1405. However, in other embodiments, the ribs 1420 can include a relatively constant thickness and / or width throughout. As shown, the tip section 1400 can include six radially aligned ribs 1420, although a fewer or more number of ribs 1420 can be included as needed or desired.

[0071] 15A is an enlarged perspective view of one exemplary catheter 1501 embodiment with a distal tip section 1500 in a first configuration having one or more internal ribs 1520. As shown, the ribs 1520 can be one or more axially positioned internal ribs 1520 that project radially inwardly along the inner surface of the section 1501 and can extend between the proximal 1503 and distal 1505 portions of the section 1500. Advantageously, the ribs 1520 positioned as shown and described provide a relatively smooth interface against the vessel and clot during advancement and aspiration, respectively. The one or more ribs 1520 can be configured to minimize the volume of material that must fold to pass through the section 1500 while maintaining structural integrity.

[0072] 15B shows a rear perspective view of section 1500. As shown, ribs 1520 in FIG. 15B include a cross-section that is significantly thicker (e.g., at least twice as thicker) than the non-ribbed sections of section 1500. In some embodiments, ribs 1520 can include a maximum width at or adjacent portion 1503 and taper therefrom to a smaller width toward portion 1505. However, in other embodiments, ribs 1520 can include a relatively constant thickness and / or width throughout. As shown, tip section 1500 can include three radially aligned ribs 1520, although tip section 1500 can have a fewer or greater number of ribs 1520 as needed or desired.

[0073] FIG. 16A is a close-up perspective view of one exemplary catheter 1601 embodiment with a distal tip section 1600 in a first configuration having one or more internal ribs 1620. As more clearly shown in the rear plan view of FIG. 16B, the ribs 1620 may be one or more axially positioned internal ribs 1620 that project radially inwardly along the inner surface of the section 1600 and may extend between the proximal and distal portions 1603 and 1605 of the section 1600. Advantageously, the ribs 1620 positioned as shown and described provide a relatively smooth outer surface interface against the vessel and clot during advancement and aspiration, respectively. The ribs 1620 may be partially formed such that the ribs 1620 may be configured to maintain the integrity of the outer profile of the section 1600 where it is most needed (e.g., near the mouth of the catheter 1601 where aspiration and clot interaction forces are highest) such that the volume of material at the largest diameter can be kept to a minimum, as more clearly shown in FIG. 16C and FIG. 16D.

[0074] As specifically shown in FIGS. 16C and 16D , the ribs 1620 can include a thicker cross-section than the non-ribbed portions of the section 1600. In some embodiments, the ribs 1620 can include a maximum width at or adjacent to portion 1603 and taper therefrom to a smaller width toward portion 1605. However, in other embodiments, the ribs 1620 can include a relatively constant thickness and / or width throughout. As shown, the tip section 1600 can include six radially aligned ribs 1620. However, the section 1600 is not so limited and can include fewer or more ribs 1620 as needed or desired. Although the illustrated ribs 1620 are shown equally spaced apart, it is contemplated that they can be positioned at various intervals.

[0075] FIG. 17A is a close-up perspective view of one exemplary catheter 1701 embodiment with a distal tip section 1700 in a first configuration having one or more internal ribs 1720. As more clearly shown in the rear plan view of FIG. 17B, the ribs 1720 may be one or more axially positioned internal ribs 1720 that project radially inwardly along the inner surface of the section 1700 and may extend between the proximal and distal portions 1703 and 1705 of the section 1700. Advantageously, the ribs 1720 positioned as shown and described provide a relatively smooth outer surface interface against the vessel and clot during advancement and aspiration, respectively. As more clearly shown in FIG. 17C, the ribs 1720 may be partially formed to keep the volume of material at the largest diameter to a minimum and the ribs 1720 may be configured to maintain the integrity of the outer profile of the section 1700 where it is most needed (e.g., near the mouth of the catheter 1701 where the aspiration and clot interaction forces are highest).

[0076] The segment 1700 may include one or more openings 1722 disposed on or adjacent the distal portion 1705 that allow blood flow to pass in a controlled manner from a proximal location to a distal location of the segment 1700 during use within a blood vessel. The one or more openings 1722 are configured to prevent collapse of the blood vessel under high suction by allowing a portion of the blood to flow through the openings 1722 when a length of the blood vessel is between the sealed segment 1700 and the sealed clot. The one or more openings 1722 may also mitigate against air ingestion during advancement through the outer catheter and against distal displacement of blood as it advances through the blood vessel. The one or more openings 1722 may be separate from the ribs 1720 (e.g., radially disposed between adjacent ribs 1720) and / or may be included in one or more of the ribs 1720 at or adjacent to the distal portion 1705.

[0077] 18A is a close-up perspective view of one exemplary catheter 1801 embodiment with the distal tip section 1800 in a first configuration. The exemplary section 1800 shown is configured to seal in a vessel having a relatively thin wall at or adjacent to the distal portion 1805, such that the portion 1813 immediately proximal to the distal portion 1805 is relatively thicker. The wall between portions 1803 and 1805 may be thicker than the shoulder defined at or adjacent to portion 1805, which in turn aids in the collapsibility of section 1800 and the overall stiffness of its outer diameter.

[0078] 18B is a close-up perspective view of one exemplary catheter 1901 embodiment with the distal tip section 1900 in a first configuration. The illustrated exemplary section 1900 is configured to seal in a vessel having a relatively thin wall at or adjacent to distal portion 1905, and tapers to be thinner at or adjacent portion 1903 such that portion 1913 just proximal to distal portion 1905 is relatively thicker. The wall between portions 1903 and 1905 can be relatively thinner to reduce the collapsed volume of section 1900 having a relatively thicker wall along portion 1917 for the overall stiffness of the catheter 1901.

[0079] FIG 19A is a close-up perspective view of one exemplary catheter 2001 embodiment with the distal tip section 2000 in a first configuration. FIG 19B is a close-up view of an exemplary shoulder section of section CC of the tip section of FIG 19A. The illustrated exemplary section 2000 is configured to seal in a vessel having a relatively thin wall at or adjacent to the distal section 2005, and includes a portion 2005a disposed on an outer curved surface of the distal section 2005, such that a portion 2013 immediately proximal to the distal section 2005 is relatively thicker. The wall between portions 2003 and 2005 may remain relatively thinner than the shoulder defined at or adjacent to portion 2005, which in turn aids in the collapsibility of section 2000 and the overall stiffness of its outer diameter. Section 2000 can include one or more support structures, such as a Nitinol braid or braided sections of one or more shape memory alloy materials, which together can include a relatively large proximally extending radius having relatively strong radial support and corresponding vessel sealing capabilities.

[0080] FIG. 19C is a close-up perspective view of one exemplary catheter 2101 embodiment with the distal tip section 2100 in a first configuration. FIG. 19D is a close-up view of an exemplary shoulder section of section DD of the tip section of FIG. 19C. Because the illustrated exemplary section 2100 is configured to seal in a vessel having a relatively thicker wall at or adjacent to the distal portion 2105, section 2101 must first evert distally before being advanced distally in the vessel. The wall between section 2103 and section 2105 can be relatively thick as well. Furthermore, because section 2101 extends proximally only a short distance above the mouth of catheter 2101, section 2100 can be easily everted for advancement and easily everted once uncovered from the catheter in a vessel large enough to allow for eversion. The thicker wall of section 2100 also aids in biasing the material towards its formed shape.

[0081] 20A is a close-up perspective view of one exemplary catheter 2201 embodiment in a first configuration with a distal tip section 2200 having a "bell" shape and a relatively thin outer membrane. The exemplary section 2200 shown is configured to seal in a vessel having a relatively thin wall at or adjacent to the distal section 2205, such that the section 2213 immediately proximal to the distal section 2205 is relatively thicker. The wall between section 2203 and section 2205 may remain thinner than the shoulder defined at or adjacent to section 2205, which in turn aids in the collapsibility of section 2200 and the overall stiffness of its outer diameter.

[0082] FIG 20B is a close-up perspective view of one exemplary catheter 2301 embodiment in which the distal tip section 2300 is in a first configuration having a "bell" shape and varying thickness therealong. FIG 20C is a close-up view of an exemplary shoulder section of section EE of the tip section 2300 of FIG 20B. The illustrated exemplary section 2300 may be configured to seal in a vessel having a relatively thin wall at or adjacent the distal section 2305 including portion 2305a, then gradually become thicker between portions 2303 and 2305a, and become relatively thin again at the outer tip adjacent portion 2303a. The shoulder defined at or adjacent portion 2305b may be relatively thicker than portion 2305a.

[0083] FIG 20D is a close-up perspective view of one exemplary catheter 2401 embodiment with the distal tip section 2400 in a first configuration. FIG 20E is a close-up view of an exemplary shoulder section of section EE of the tip section 2400 of FIG 20D. The illustrated exemplary section 2400 is configured to provide a relatively stiff support that seals in vessels having relatively thick walls at or adjacent to distal section 2405 including portion 2405a, with the remainder between section 2403 and section 2405 being relatively thin at or around section 2403a, and terminating distally at feather edge adjacent section 2403. Section 2400 can then be configured to easily collapse in a wider range of vessel sizes, allowing for advancement through smaller vessels.

[0084] FIG 21A is an enlarged perspective view of one exemplary catheter 2501 embodiment in a first configuration with a distal tip section 2500 having a "bell" shape that terminates in a relatively large proximal extension radius, which is relatively shorter than the previously described "bell" shaped sections. Section 2500 is then specially configured to allow for relatively smooth inversion when pulled proximally through an outer sheath. FIG 21B is an enlarged view of an exemplary shoulder section of section EE of tip section 2500 of FIG 21A. The illustrated exemplary section 2500 is configured to seal in a vessel having a relatively thin wall at or adjacent distal portion 2505, including portion 2505a, and then thicken at or adjacent distal portion 2505b (and proximal to distal portion 2505b toward portion 2517), but thin on the opposing side of distal portion 2505b at or around portion 2503.

[0085] FIG. 22A is an enlarged side view of another exemplary distal tip section 2600 in a first configuration, where section 2600 can be formed on a braided, wire, or laser cut support frame. Such a support frame can allow for the use of a very thin membrane (e.g., 5-50 micrometers) without losing the integrity of the shape of section 2600, so that section 2600 in conjunction with the remaining sections of the catheter can withstand suction forces, clot ingestion, and compression within the outer catheter and through the blood vessel. In some embodiments, section 2600 can include a support frame made from a metallic and / or polymeric material. Metals and certain heat-resistant polymers can be amenable to forming the membrane of section 2600 by reflow molding, molding, and compression molding processes. In other embodiments, a dipping process can be used to construct section 2600 with a metallic and / or polymeric support frame, where the polymer is compatible with the solvent used for the membrane dipping material.

[0086] Figure 22B is a close-up side view of another exemplary distal tip section 2700 in the first configuration where the support frame is constructed from a plurality of wires. Figure 22C is a close-up side view of another exemplary distal tip section 2800 in the first configuration where the support frame is laser cut.

[0087] FIG. 22D is an enlarged side view of another exemplary distal tip section 2900 in a first configuration. In this example, section 2900 can include one or more polymer layers, e.g., layers 2950, ​​2960. In some examples, membrane layer 2950 can be adhered to thin film 2960, such that layer 2950 can be a stiffer longitudinal support member with a corresponding increased bending stiffness relative to membrane 2960, which in turn provides adequate radial support to section 2900. FIG. 22E is an enlarged side view of another exemplary distal tip section 3000 in a first configuration, similar to section 2900, except that section 3000 includes an additional outer membrane layer in this case positioned over (rather than underneath, as in section 2900) the one or more stiffer longitudinal support members.

[0088] FIG. 22F is an enlarged side view of another exemplary distal tip section 3100 in the first configuration. In this example, section 3100 can include one or more polymer layers, such as layer 3107. Layer 3107 can be a membrane that is flexible but rigid enough to provide support with one or more notches to which window 3110 is adhered. Window 3110 can be porous to further increase the ability to collapse in a minimal volume while allowing controlled passage of blood flow. The passage of blood flow in this embodiment can help to keep the relatively thin membrane of section 3100 in its formed shape during aspiration, similar to a parachute. FIG. 22G is an enlarged side view of another exemplary distal tip section 3200 in the first configuration, similar to section 3100, except for section 3200 including a proximally extending window 3210, which in certain examples is similar to section 3100.

[0089] 23 is a side view of an embodiment of a catheter 3301 with a distal tip section 3300 in a first configuration and positioned with an exemplary luer 3470. As shown, the section 3300 can include a collapsible shaft portion 3337 (e.g., a shaft constructed of a braided frame) below the outer surface of the section 3300. When advanced through the luer 3471 of the outer catheter or folded through the luer 3471, the collapsible shaft portion 3337 can fold or pleat into the inner diameter (ID) of the outer shaft providing additional space for the relatively soft section 3300. To accomplish this function, the support frame of the section 3337 can include the braided frame described above. However, the support frame is not so limited and can be of wire construction or a laser cut stent-like tube has an elastomeric polymer or polymer with elastic strain recovery properties reflowed through or molded over the structure. In some embodiments, just proximal to portion 3337 , catheter 3301 can include a non-collapsible shaft portion 3335 .

[0090] In some embodiments, portion 3337 can have one or more axial spines 3342 to increase the pushability and resistance to tensile elongation of the shaft. The one or more axial spines 3342 can terminate short of (e.g., can be positioned just proximal to) tip section 3300, extend to the distal end of section 3337 or to the distal end of section 3337, and return proximally through the wall of section 3300.

[0091] In some embodiments, the section 3337 can be fitted with a ring or coil marker band 3330 for increased visibility. Alternatively, radiopaque wires or coils can be added to the frame of the section 3337 (or other marker inserts can be included in the laser cut support frame, or radiopaque fillers can be included in the soft material of the section 3300). The catheter 3301 can also include a series of polymer jackets 3350 with different flexibility characteristics to provide variability in bending flexibility and pushability. The jackets 3350 can be reflowed over a PTFE liner for a low friction inner lumen, and support structures (e.g., coils, braids, laser treated tube patterns, spines, or combinations thereof) on the PTFE liner to provide kink resistance, torque and pushability characteristics.

[0092] Referring to Figure 24A, a side view of the catheter 3301 is shown with the section 3300 in a first configuration within the guide catheter 3400 having exemplary luers 3440, 3470. Figure 24B shows a similar view, but the section 3300 has now been translated distally to the distal end of the catheter 3400. As shown, once inside the catheter 3400, the catheter 3301 including the section 3300 has a reduced outer diameter to pass therethrough, and once distal thereto, the section 3300 can automatically expand.

[0093] FIG. 25A is a close-up view of the catheter 3301, 3400 of FIG. 24A at section HH, more clearly showing the tip section 3301 when folded into the catheter 3400. FIG. 25B is a close-up view of the catheter 3301, 3400 of FIG. 24B at section II, more clearly showing the tip section 3301 at least partially distal to the catheter 3400 and when sections 3305, 3303 have expanded to a diameter larger than their previous folded diameter. In certain embodiments, the maximum diameter formed between sections 3303 and 3305 may be larger than the outer diameter of the catheter 3400. In some embodiments, the maximum diameter may be at least two times larger than the outer diameter of the catheter 3400. However, sections 3300 are not limited to any diameter, and larger or smaller diameters may be used as needed or desired.

[0094] 26, an exploded side view of the catheters 3400, 3301 with the corresponding tip sections 3300 push-loaded through the taper lock luer 3450. The sections 3300 are configured to reduce in diameter when advanced through the taper lock luer 3450 of the outer catheter 3400. In some embodiments, the luer 3450 can be a custom luer with an internal taper. For example, the luer 3450 can include a surface 3457 configured to develop a step of taper to reduce the internal diameter reduction, such that the luer 3450 can be positioned or otherwise threaded onto the taper lock luer 3450, providing a seamless transition to reduce the diameter of the section 3300 in a stepwise manner. The luer can also include an outer mounting flange 3459 with a maximum diameter of the luer 3450, and an opposite distal end 3453 with a minimum diameter of the luer 3450.

[0095] The luer 3450 may include a split design so that it can be removed from the assembly after the section 3300 has passed and reduced in diameter. Removing the loading luer 3450, in some embodiments, can ensure that the usable length of the shaft of the catheter 3301 is not reduced, and the split design may be removed by twisting, pulling apart the snap-fit ​​features, or pulling on the magnetically coupled sides of the luer 3450.

[0096] Referring to Fig. 27A, an exploded side view of the catheter 3301 being push loaded through the taper lock 3450 and the second loading luer 3480. Fig. 27B is a side view of the embodiment of Fig. 27A positioned with the locks 3450, 3480. As shown, the OD of the luer 3450 can be contoured to fit inside the ID of the luer 3480, which can be a solid loading luer. In this regard, the inclusion of the luer 3480 does not reduce the usable length of the catheter shaft associated with the catheter 3301 and the luer 3480, and the luer 3480 does not need to be removed to maximize the usable length of the catheter 3301. The luer 3301 can also be compatible with a hemostasis valve.

[0097] 28A, which is a side view of a catheter 3301 being push-loaded distally by a loading tool 3460, associated with features previously described, to distally flip section 3300 as indicated by the large arrow representing directional movement. In FIG. 28B, the tool 3460 has been translated distally from FIG. 28A until the flipped section 3000 is aligned with the distal end of the tool 3406.

[0098] FIG. 29A shows a third configuration, where the distal end of the tool 3460 with the inverted section 3300 is inserted into the luer 3450 of the catheter 3400. In other examples, the luer 3450 may instead be a hemostasis valve connected to the luer 3450. Referring to FIG. 29B, a fourth configuration is shown with the section 3300 advanced distally through the catheter 3400 until it exits distally, preferably into a vessel having an ID greater than the OD of the section 3300. In some embodiments, exiting distally as described and illustrated can allow the section 3300 to return to its original "earbud" shape, as shown in FIG. 29B. The section 3300 can then be advanced distally through the vessel to the treatment site.

[0099] FIG. 30 is a flow diagram illustrating steps of a method for using any of the catheters disclosed herein for occlusive thrombus from a blood vessel. The method steps may be performed by any of the exemplary systems, devices, and / or instruments described herein or by means known to one of skill in the art. With reference to method 3000 outlined in FIG. 30, step 3010 describes moving a distal tip section of the aspiration catheter from a collapsed configuration to a first expanded configuration by translating the aspiration catheter at least partially distal to a sheath or delivery catheter. Step 3020 describes retracting the distal tip section to flip the distal tip section about a transition between the distal tip section and the catheter body to a second expanded configuration, the second configuration comprising an expandable tip having an open funnel-like distal mouth that includes a diameter larger than the diameter of the transition.

[0100] In some embodiments of method 3000, the distal tip section can also be configured to not invert when pulled proximally through the blood vessel, but only invert when retracted through the outer sheath.

[0101] In some embodiments of method 3000, depending on how the user deployed the flow restriction and / or seal, suction can be applied through the aspiration catheter to urge the clot into the catheter's funnel mouth. If suction alone is insufficient to dislodge and capture the clot, or if further gripping of the clot is desired during initial aspiration and removal, a mechanical thrombectomy clot retriever can be advanced to the target. The mechanical thrombectomy device can then be deployed to capture the clot using any method commonly known in the art. Suction can be continued throughout the process or at intervals selected by the user to prevent blood reflux and maintain a tight grip on the clot. In some instances, aspiration and pulling of the clot with a stent retriever can be optimal to increase the chances of first-pass success.

[0102] In some embodiments of method 3000, the captured clot and clot retrieval catheter can be withdrawn from the patient, or the clot retrieval catheter can be left in place to maintain access as the mechanical thrombectomy clot retrieval device is withdrawn from the patient along with the clot. If a clot is observed at the aspiration source and / or thrombectomy device and flow is not blocked in the clot retrieval catheter, this step may involve carefully injecting contrast under low pressure into the system using known techniques to determine if the vessel is open. If the vessel is open, the clot retrieval catheter can be removed. If an obstruction remains, additional passes of aspiration, thrombectomy, or a combination thereof may be repeated until the vessel is open.

[0103] In some embodiments, the aspiration catheter and corresponding system are configured to create a clot retrieval catheter that can provide both localized flow restriction and / or cessation and a large clot facing ostium. In some embodiments, the aspiration catheter of the present disclosure can navigate tortuous neurovasculature to reach occlusive clots and can be highly flexible. In some embodiments, the aspiration catheter can be compatible with a relatively low profile access sheath and outer catheter, allowing easy and reliable closure of a puncture wound in the patient's groin (e.g., femoral access). In some embodiments, the aspiration catheter and corresponding system of the present disclosure are particularly suited for removing clots from the cerebral arteries of patients suffering from AIS, from native or graft vessels of patients suffering from MI, from the pulmonary arteries of patients suffering from pulmonary embolism, and from other peripheral arteries and veins where clots are causing obstruction.

[0104] The present disclosure is not limited to the described examples, which may vary in configuration and details. The terms "distal" and "proximal" are used throughout the foregoing description and are meant to refer to a location and direction relative to the treating physician. Thus, "distal" or "distally" refers to a location away from the physician or a direction away from the physician. Similarly, "proximal" or "proximally" refers to a location closer to the physician or a direction toward the physician.

[0105] In describing the exemplary embodiments, technical terms are used for clarity. Each term is intended to have its broadest meaning as understood by those skilled in the art, and is intended to include all technical equivalents that operate in a similar manner to achieve a similar purpose. It should also be understood that a reference to one or more steps of a method does not preclude the presence of additional or intervening method steps between those steps that are explicitly identified. Each step of the method can be performed in a different order than that described herein without departing from the scope of the disclosed technology. Similarly, it should also be understood that a reference to one or more components in an apparatus or system does not preclude the presence of additional or intervening components between those components that are explicitly identified.

[0106] As discussed herein, a "patient" or "subject" can be a human or any animal. It should be understood that the animal can be of any of a variety of relevant types, including, but not limited to, mammals, veterinary animals, livestock animals, or pet animals. As an example, the animal can be a laboratory animal (e.g., rats, dogs, pigs, monkeys, etc.) that is specifically selected to have certain characteristics similar to humans.

[0107] The term "about" or "approximately" as used herein with respect to any numerical value or range of numerical values ​​indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function according to its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value, for example, "about 90%" may refer to a range of values ​​of 71% to 99%.

[0108] "Comprising" or "containing" or "including" means that at least the specified compounds, elements, particles, or method steps are present in a composition or article or method, but does not exclude the presence of other such compounds, substances, particles, or method steps, even if those other compounds, substances, particles, or method steps have the same function as the one specified.

[0109] It should also be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges can be expressed herein as from "about" or "approximately" one particular value to "about" or "approximately" another particular value. When such a range is expressed, other exemplary embodiments also include from the one particular value to the other particular value.

[0110] The descriptions contained herein are examples of embodiments of the present disclosure and do not limit the scope of the present disclosure in any way. Although specific examples of the present disclosure are described, various modifications to the apparatus and method can be made without departing from the scope and spirit of the present disclosure. For example, the examples described herein refer to specific components, but the present disclosure includes other examples that utilize combinations of various components to achieve the described functionality, utilize alternative materials to achieve the described functionality, combine components from various examples, combine components from various examples with known components, and the like. The present disclosure contemplates the replacement of component parts exemplified herein with other known commercially available products. These modifications will be apparent in many cases to those skilled in the art to which the present disclosure pertains, and are intended to be within the scope of the following claims.

[0111] [Embodiment] (1) A catheter comprising: a distal tip section disposed at or adjacent to a distal end of the catheter, the distal tip section being reversible about a transition between a catheter body and the distal tip section between a first configuration and a second configuration; the catheter is configured to cause the distal tip section to flip about the transition from the first configuration to the second configuration by retracting the distal tip section; The second configuration comprises an expandable tip having an open, funnel-like distal mouth with a diameter larger than a diameter of the transition section. (2) The catheter of embodiment 1, wherein the first configuration and the second configuration are part of an expanded configuration of the distal tip section distal to a guide catheter or sheath. (3) The catheter of embodiment 1, wherein the first configuration of the distal tip section comprises a mushroom-shaped hemispherical section configured to be inverted into the second configuration by retracting a predetermined distance to form the open funnel-like distal mouth. (4) The catheter of embodiment 3, wherein the mushroom-shaped hemispherical sections are mirror images of one another between the first configuration and the second configuration. (5) The catheter of embodiment 1, wherein the distal tip section comprises a plurality of sealing members configured to be inverted from a mushroom-shaped section in the first configuration with an open end facing proximally to an open funnel-like distal mouth in the second configuration with the open end facing distally.

[0112] (6) The catheter of embodiment 5, wherein each sealing member includes a hemispherical shape in the first configuration and the second configuration, the hemispherical shapes being substantially opposite mirror images of one another between the first configuration and the second configuration. (7) A catheter as described in embodiment 5, wherein each sealing member corresponds to a separate funnel orifice in the second configuration. (8) A catheter as described in embodiment 5, wherein each sealing member corresponds to multiple sealing layers with a corresponding blood vessel wall. (9) A catheter as described in embodiment 5, wherein each sealing member is reversible at each transition portion. (10) A catheter as described in embodiment 5, wherein each sealing member is selectively spaced along the catheter body.

[0113] (11) The catheter of embodiment 1, wherein the distal tip section comprises a proximal portion and a distal portion, the distal portion having a diameter smaller than a diameter of the proximal portion, and the diameter of the proximal portion is at least twice the diameter of the distal portion. (12) The catheter of embodiment 1, wherein the distal tip section comprises a proximal portion and a distal portion, the distal portion including a diameter smaller than a diameter of the proximal portion, and an outer surface of the distal tip section between the proximal portion and the distal portion is curved or otherwise contoured. (13) The catheter of embodiment 1, wherein the open funnel-like distal port is collapsible during or after a procedure to reduce or eliminate flow restriction within the blood vessel. (14) A method comprising the steps of: moving the distal tip section of the aspiration catheter from a collapsed configuration to a first expanded configuration by translating the aspiration catheter at least partially distal to a sheath or delivery catheter; and retracting the distal tip section to cause the distal tip section to invert to the second expanded configuration about a transition between the distal tip section and a catheter body of the aspiration catheter, the second configuration comprising an expandable tip having an open, funnel-like distal mouth comprising a diameter greater than a diameter of the transition. 15. The method of claim 14, further comprising aspirating through the distal tip section to encourage thrombus into the open funnel-like distal mouth of the distal tip section.

[0114] (16) The method of embodiment 14, further comprising reducing clot shear with the distal tip section in the first configuration. 17. The method of claim 14, further comprising inverting the plurality of sealing members of the distal tip section from a mushroom-shaped section in the first configuration to the open funnel-like distal mouth in the second configuration. 18. The method of claim 17, further comprising inverting the sealing member of each of the distal tip sections to form a corresponding funnel-like distal port. (19) The method of embodiment 17, further comprising sealing the plurality of sealing layers with a respective sealing layer of each sealing member to a corresponding vessel wall, each sealing member being invertible about a respective transition portion. (20) The method of embodiment 14, further comprising collapsing the open funnel-like distal port during the procedure to reduce or eliminate flow restriction within the blood vessel.

Claims

1. A catheter comprising: a distal tip section disposed at or adjacent to a distal end of the catheter, the distal tip section being reversible about a transition between a catheter body and the distal tip section between a first configuration and a second configuration; the catheter is configured to cause the distal tip section to flip about the transition from the first configuration to the second configuration by retracting the distal tip section; the second configuration comprises an expandable tip having an open, funnel-like distal mouth with a diameter greater than a diameter of the transition section; a distal tip section having a plurality of sealing members configured to be inverted from a mushroom-shaped section in a first configuration with an open end facing proximally to an open funnel-like distal mouth in a second configuration with the open end facing distally.

2. The catheter of claim 1 , wherein the first configuration and the second configuration are part of an expanded configuration of the distal tip section distal to a guide catheter or sheath.

3. 2. The catheter of claim 1, wherein the first configuration of the distal tip section comprises a mushroom-shaped hemispherical section configured to be inverted into the second configuration by retracting a predetermined distance to form the open, funnel-like distal mouth.

4. The catheter of claim 3 , wherein the mushroom-shaped hemispherical sections are mirror images of one another between the first and second configurations.

5. 2. The catheter of claim 1, wherein each sealing member includes a hemispherical shape in the first configuration and the second configuration, the hemispherical shapes being substantially opposing mirror images of one another between the first and second configurations.

6. The catheter of claim 1 , wherein each sealing member corresponds to a separate funnel orifice in the second configuration.

7. The catheter of claim 1 , wherein each sealing member corresponds to a plurality of sealing layers with a corresponding vessel wall.

8. The catheter of claim 1 , wherein each sealing member has a respective transition that is reversible.

9. The catheter of claim 1 , wherein each sealing member is selectively spaced along the catheter body.

10. 2. The catheter of claim 1, wherein the distal tip section comprises a proximal portion and a distal portion, the distal portion including a diameter smaller than a diameter of the proximal portion, the diameter of the proximal portion being at least twice the diameter of the distal portion.

11. 10. The catheter of claim 1, wherein the distal tip section comprises a proximal portion and a distal portion, the distal portion including a diameter smaller than a diameter of the proximal portion, and an outer surface of the distal tip section between the proximal portion and the distal portion is curved or otherwise contoured.

12. The catheter of claim 1 , wherein the open funnel-like distal port is collapsible during or after a procedure to reduce or eliminate flow restriction within a blood vessel.

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