Collection systems and methods

Abstract

A catheter system comprising an inner tube movable within an outer tube, and a funnel-shaped sleeve attached to the inner tube and configured to transition between a collapsed state when isolated within the outer tube and an expanded state when advanced out of the outer tube.

Description

[Technical field]

[0001] The present invention relates to a catheter having a funnel-shaped trap that is highly effective in capturing and retrieving cerebral emboli / thrombi. [Background technology]

[0002] The number of interventional procedures used to treat vascular lesions that are not easily accessible by surgical procedures has continued to increase in recent years.

[0003] Such interventional procedures are particularly advantageous when used to treat lesions located in small, remote blood vessels, such as those in the brain.

[0004] Cerebral embolism is a vascular event caused when a material, typically a blood clot, travels and blocks a blood vessel that supplies brain tissue.

[0005] One conventional technique for retrieving cerebral emboli involves the use of a retrieval catheter having a funnel-shaped trap that is used to capture and retrieve the emboli.

[0006] While such retrieval devices are effective at retrieving small clots, retrieval of larger clots can cause the clot to fragment, releasing potentially harmful clot particles into the bloodstream.

[0007] Thus, there remains room for improvement in clot retrieval systems, particularly the clot association and retraction capabilities of such systems. Summary of the Invention

[0008] According to one aspect of the present invention, there is provided a catheter system for retrieving material from a biological vessel, the catheter system comprising: an inner tube movable within an outer tube; a funnel-shaped sleeve attached to the inner tube and configured to transition between a collapsed state when isolated within the outer tube and an expanded state when advanced out of the outer tube; and a mechanism or indicator for allowing a user to advance a predetermined length of a portion of the sleeve out of the outer tube.

[0009] According to an embodiment of the invention, the mechanism is a trigger for causing the advancement of the portions.

[0010] According to an embodiment of the present invention, the indicator includes markings to indicate advancement of the portion.

[0011] According to an embodiment of the present invention, the sleeve is a braided sleeve.

[0012] According to an embodiment of the present invention, the braided sleeve decreases in length when expanded.

[0013] According to an embodiment of the present invention, the braided sleeve includes a cover.

[0014] According to an embodiment of the present invention, the cover is made from polyurethane, TPU, PTFE or silicone.

[0015] In accordance with an embodiment of the present invention, the catheter system further comprises a conduit for applying suction within the braided sleeve.

[0016] In accordance with an embodiment of the present invention, the catheter system further comprises a vacuum source in communication with the conduit.

[0017] According to an embodiment of the present invention, a portion of the sleeve of a predetermined length forms a cone when advanced out of the outer tube.

[0018] According to an embodiment of the present invention, the distal opening of the sleeve includes a closure mechanism.

[0019] According to an embodiment of the present invention, the closure mechanism comprises a pull wire.

[0020] According to an embodiment of the present invention, the pull wire pinches the distal opening closed.

[0021] According to an embodiment of the invention, the pull wires are positioned to allow separation of the material from the wall of the funnel sleeve.

[0022] According to an embodiment of the invention, the distal end of the sleeve is tapered such that when expanded, the opening of the sleeve forms a tilted oval.

[0023] According to an embodiment of the present invention, the funnel sleeve includes a radiopaque marker band.

[0024] According to an embodiment of the invention, the braided sleeve includes a wire loop at the distal end.

[0025] According to an embodiment of the present invention, the cover comprises a hydrophobic coating.

[0026] According to an embodiment of the present invention, the catheter system further comprises a conduit for injecting a dye.

[0027] According to an embodiment of the present invention, the catheter system further comprises at least one sensor for identifying the presence of a substance within the funnel sleeve.

[0028] According to an embodiment of the invention, a first sensor of the at least one sensor is disposed in a proximal region of the funnel-shaped sleeve.

[0029] According to an embodiment of the invention, a second of the at least one sensor is disposed in a distal region of the funnel-shaped sleeve.

[0030] In accordance with an embodiment of the present invention, the catheter system further comprises a plurality of flexible arms disposed within and attached to the funnel-shaped sleeve.

[0031] According to an embodiment of the present invention, the funnel sleeve has an hourglass shape when fully deployed.

[0032] In accordance with another aspect of the present invention, there is provided a method of retrieving material from a biological vessel, the method including the steps of partially advancing a funnel-shaped sleeve out of a tube of a catheter positioned within the biological vessel to form a cone of a predetermined length within the biological vessel, aspirating material within the biological vessel into the cone, and trapping the material within the funnel-shaped sleeve by further advancing the funnel-shaped sleeve out of the tube and applying suction.

[0033] According to an embodiment of the invention, the aspirating step is performed while advancing the catheter in the direction of the substance.

[0034] According to an embodiment of the present invention, the method further comprises the step of closing a distal end of the funnel-shaped sleeve.

[0035] According to an embodiment of the present invention, the catheter is advanced through the biological vessel after partial deployment.

[0036] According to another aspect of the present invention, there is provided a catheter system for retrieving material from a biological vessel, the catheter system comprising: an inner tube movable within an outer tube; a funnel-shaped sleeve attached to the inner tube and configured to transition between a collapsed state when isolated within the outer tube and an expanded state when advanced out of the outer tube; and a plurality of flexible arms disposed within and attached to the funnel-shaped sleeve, the plurality of flexible arms configured to allow material to enter the funnel-shaped sleeve while preventing the material from being expelled from the funnel-shaped sleeve.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.Methods and materials similar or equivalent to those described herein can be used to carry out or test this invention, but suitable methods and materials are described below.In case of conflict, the patent specification including definitions shall prevail.In addition, materials, methods, and examples are merely illustrative and are not intended to be limiting.

[0038] The present invention is described herein by way of example only, with reference to the accompanying drawings. With particular reference now to the drawings in detail, it is emphasized that the details shown are by way of example and are for the sole purpose of illustrative description of preferred embodiments of the invention, presented to provide what is believed to be the most useful and readily understood explanation of the principles and conceptual aspects of the invention. In this regard, no attempt has been made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, and the description, taken together with the drawings, will make apparent to those skilled in the art how several forms of the invention may be embodied in practice. [Brief description of the drawings]

[0039] [Figure 1] 1A-F show embodiments of the present catheter system including a shovel-shaped funnel (FIGS. 1A,D-F), a standard funnel (FIG. 1B), a trigger release handle (FIGS. 1A-B) and a handle with markings (FIG. 1C). [Diagram 2] Figures 2A-C show a two-stage deployment of the shovel funnel catheter configuration. Figures 2D-E show the shovel configuration in more detail showing the leaflets formed from the wire loops. [Diagram 3] 3A-C show a two-stage deployment of a standard funnel catheter configuration. [Figure 4] Figures 4A-C show clot capture using a shovel funnel catheter configuration. Figures 4D-F show clot capture using a shovel funnel catheter configuration with flexible arms. [Diagram 5]5A-C show clot capture using a standard funnel catheter configuration. [Figure 6] 6A-B show the trigger handle (FIG. 6A) or markings (FIG. 6B) used for partial deployment of a shovel or a standard funnel. [Figure 7] 7A-C are fluoroscopic images of clot capture in a porcine model using the present catheter system with a standard funnel. [Figure 8] Figures 8A-B are fluoroscopic images of clot capture in a porcine model using the present catheter system equipped with a shovel funnel, and Figure 8C is an image of clot material retrieved by the procedure shown in Figures 8A-B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] The present invention is a catheter system and method that can be used to retrieve material / objects, such as emboli, from biological vessels, such as blood vessels.

[0041] The principles and operation of the present invention may be better understood with reference to the drawings and accompanying descriptions.

[0042] Before describing at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details set forth in the following description or illustrated by the examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[0043] Mechanical thrombectomy devices that utilize a trap to retrieve clot material are known in the art. Such traps can include a closable distal opening to retain the retrieved clot within the sleeve while minimizing release of the clot or fragments from the trap as it is withdrawn from the vasculature.

[0044] In a previously filed patent application (WO2019064306), the inventors disclosed a unique trap closure mechanism that substantially enhances the retrieval of the entire clot. In reducing the present invention to practice, the inventors set out to improve the clot-trapping capability, especially in the case of large clots.

[0045] Thus, according to one aspect of the present invention, there is provided a catheter system for retrieving a substance or object from a biological vessel.

[0046] As used herein, the term "material" refers to biological material such as that which characterizes a thrombus / embolus, while the term "object" refers to an implant such as a stent, stent graft, etc.

[0047] The system can be used to access and treat any biological vessel, examples include vessels of the circulatory system (e.g., arteries, veins, lymphatic vessels), vessels of the urinary tract (e.g., urethra, ureters), and vessels of the lymphatic system.

[0048] The system of the present invention comprises a funnel-shaped sleeve configured to transition between a collapsed state and an expanded state. When in the expanded state, the funnel-shaped sleeve is shaped like a funnel that tapers in diameter from the distal end to the proximal end. The funnel comprises a lumen accessible through a distal opening that may be circular and perpendicular to the longitudinal axis of the catheter (also referred to herein as a "standard configuration") or elliptical and tilted / angled relative to the longitudinal axis of the catheter (also referred to herein as a "shovel configuration").

[0049] When collapsed, the funnel sleeve becomes a narrow cylinder with a small lumen (large enough to pass a guidewire and / or a microcatheter through). The funnel sleeve is self-expandable, where at least a portion of it self-expands to a final diameter limited by the diameter of the blood vessel (and to a diameter limited by the braided structure and the degree of deployment from the catheter sheath).

[0050] According to one embodiment of the invention, the funnel sleeve can be fabricated from metal (e.g., stainless steel or nitinol) or polymer (e.g., PTFE) wires braided in alternating helical and counter-helical directions. The braid can be covered (fully or partially) with a polymer such as TPU or polyurethane so that a vacuum can be applied to the interior volume of the funnel sleeve.

[0051] The diameter of the wires may be 0.02-0.25 mm, while the braid angle between the wires may range from 60-140 degrees. The funnel-shaped sleeve can be manufactured using an appropriately sized mandrel by wrapping the wires in an alternating helical pattern. For example, a single wire can be looped and the tail of the loop can be wrapped in a helical pattern around the mandrel to form a crisscross pattern (1×1 pattern) or a crisscross pattern (2×1 pattern) for every two wires along the length of the mandrel. Several wires (12-64) can be used to form the braided structure. A braided structure of the same pattern with a smaller diameter (Figure 1G) is advantageous in some configurations as it increases the radial force of the funnel, thereby preventing collapse under suction. Examples of such braids are provided in WO2019064306. The funnel-shaped sleeve can be equipped with a wire loop at its distal end (surrounding the opening of the expanded funnel-shaped sleeve). The wire loops provide axial support and form leaflets that reduce braid compression when the funnel sleeve contacts the clot (thereby minimizing the accordion effect that can occur when the braided structure is forced against the clot). The wire loops also form soft tips that minimize vessel trauma during deployment. During aspiration, these wire leaflets collapse around and encapsulate the clot without causing collapse of the braided structure.

[0052] The parameters and dimensions of the catheter and funnel sleeve vary depending on the application and type of vessel. When used for ischemic stroke applications in intracranial arteries, the size of the target artery can vary between 2.5-4.5 mm. The diameter of the funnel sleeve must be at least slightly larger than the diameter of the vessel to stop blood flow, and therefore ranges from 2-7 mm. The length of the funnel sleeve can be long enough to support accepting a long blood clot within the lumen, but short enough that the funnel sleeve can be deployed by pushing it out of the outer tube of the catheter or by retracting the sheath.

[0053] The system also includes a catheter for delivering the funnel sleeve into the blood vessel. According to one embodiment of the invention, the funnel sleeve is attached to the distal end of the catheter inner tube (shaft) and may be covered by a removable sheath (outer tube) when in a collapsed configuration. Removal of the sheath (pulling proximally) allows the funnel sleeve to be deployed.

[0054] In another embodiment of the invention, the funnel sleeve is captured in a folded state within the lumen of the outer tube of the catheter and pushed for deployment through an inner tube that is attached to the proximal end of the funnel sleeve.

[0055] The catheter system may also include a suction source (e.g., syringe, pump) capable of applying suction to the lumen (internal volume) of the funnel sleeve via a dedicated conduit that fluidly connects the suction source to the lumen of the funnel sleeve. The inner tube of the catheter may also function as a fluid conduit.

[0056] Experiments performed by the inventors have revealed that the distal opening of a fully extended funnel sleeve may sometimes be blocked by a large thrombus when suction is applied to the lumen of the funnel sleeve, and such blockage may cause the funnel sleeve to collapse upon suction.

[0057] The inventors have discovered that partially deploying the funnel sleeve such that a 2-8 mm long cone extends from the catheter or is uncovered by a sheath substantially improves the ability of the system to collect thrombus material without occlusion or collapse. Thus, the inventors have devised an approach in which the cone portion of the funnel sleeve is deployed first (at the thrombus or deployed and advanced to the thrombus), the thrombus engages this portion and is aspirated, and then the remainder of the funnel sleeve is gradually deployed while maintaining suction to completely aspirate and capture the thrombus.

[0058] With this approach, the system aspirates the thrombus, increasing the volume of the funnel as it sucks in the thrombus.

[0059] To enable such functionality, the catheter system includes a mechanism or indicator that allows for partial deployment of the funnel sleeve. The mechanism can include a trigger for precise partial deployment of the funnel sleeve, or an indicator with markings that allows the user to deploy a specific length of the funnel sleeve.

[0060] Referring now to the drawings, FIGS. 1A-D show a catheter system of the present invention, hereinafter referred to as system 10.

[0061] The system 10 comprises a catheter shaft comprising an outer tube 12 surrounding an inner tube 14. The inner tube 14 is attached to a funnel-shaped sleeve 16 (shown expanded in FIGS. 1A-1C) that is used to capture (within its lumen) and retrieve material or objects from a biological vessel (e.g., an artery). The funnel-shaped sleeve 16 comprises a distal opening 34 and a lumen 33 and can be one of two types: a shovel-shaped, funnel-shaped sleeve 16 (FIGS. 1A, 1C, 1D) or a standard funnel-shaped sleeve 16 (FIG. 1B).

[0062] The inner tube 14 may be an elongated hollow tube selected for length, diameter and flexibility appropriate to the intended treatment site. Different anatomical sites require inner tubes 14 of different stiffness and axial flexibility. Inner tubes 14 with variable stiffness and axial flexibility along the length of the shaft are well known in the art and may be braided or coiled, including an inner coating of low friction material such as PTFE, a metal braid or coil on the inner layer, and an outer polymer layer (jacket) such as PEBAX or polyamide composites of various durometer ratings. Such tubes are commonly used for delivery to tortuous or intracranial vasculature.

[0063] The outer tube 12 may be an elongated hollow tube that can be slid over the inner tube 14. The length of the inner tube 14 may be shorter than the length of the inner tube 14, allowing the outer tube 12 to be pulled back for partial and full deployment of the funnel-shaped sleeve 16.

[0064] The outer tube 12 is selected for a length, diameter, and flexibility appropriate for the intended treatment site. The required high distal flexibility and tracking performance is achieved by selecting a soft material jacket and metal coil design. The outer tube 12 can be of different stiffness and axial flexibility as well as proximal stiffness and pushability for delivery to tortuous anatomical structures. Tubes with variable stiffness and axial flexibility along their length are well known in the art. Such tubes can be braided or coiled and include an inner polymer layer with a low friction layer (e.g., PTFE), metal braids and coils in different sections covering the inner layer, and an outer polymer layer (jacket) such as PEBAX, polyurethane or polyamide composites with various durometer ratings.

[0065] The outer diameter of the inner tube 14 may be 0.5-4 mm (e.g., 1.5 mm), while the inner diameter of the inner tube 14 (which may function as an aspiration conduit) may be 0.3-3.5 mm. A wire lumen (for closure) may be separate from the inner lumen and may be 0.03-0.3 mm in diameter (which may be located in the wall of the inner tube 14). The length of the inner tube 14 may range anywhere between 50-150 cm and is selected depending on the target vessel and the site to be treated.

[0066] The outer diameter of the outer tube 12 may be 1-6 mm, while the inner diameter of the outer tube 12 (which houses the inner tube 14) may be 0.8-5.5 mm. The length of the outer tube 12 may range anywhere between 45-145 cm, and is selected depending on the target vessel and the site to be treated.

[0067] The funnel-shaped sleeve 16 may be 5-80 mm long and taper in diameter from 1-20 mm (distal) to 0.3-18 mm (proximal) when fully deployed and 10-160 mm when isolated within the outer tube 12. The funnel-shaped sleeve 16 (standard or shovel) may alternatively have an hour-glass shape when deployed (Figure 1D). The hour-glass shape has the advantage that the difference in diameter in the two regions of the funnel-shaped sleeve 16 (marked as proximal, distal, R1 and R2 respectively) creates a pressure difference between the funnel sections (proximal-distal) due to Bernoulli's principle, thus helping to advance material towards the proximal region (R1) of the funnel. Another advantage is that the proximal region (R1) can capture and hold the thrombus and prevent its release due to its smaller diameter (Figure 1F) (it collapses on the material).

[0068] The hourglass shape of the funnel sleeve 16 (FIG. 1G) has the advantage that the PPI (pitch per inch) increases in the narrowing region (e.g., the transition from R2 to R1), which increases the stiffness of the funnel and thus prevents it from collapsing under suction.

[0069] Deployment of the funnel-shaped sleeve 16 can be accomplished by pulling back (proximally) the outer tube 12 using a handle 18 attached to the outer tube 12 (FIG. 1A) or by pushing the inner tube 14 (distally) relative to the handle 18. The markings 20 can be used to determine the length of the deployed funnel-shaped sleeve 16. Such markings can be used to partially deploy the funnel-shaped sleeve 16 to form a cone-like shape of a predetermined length (FIGS. 2B, 3B).

[0070] 6B shows in more detail the handle 18 that can be moved with the outer tube 12 to partially and then fully deploy the funnel-shaped sleeve 16. The handle 18 includes a button 19 for releasing / locking movement of the outer tube 12 relative to the inner tube 14. Markings 20 on the inner tube 14 indicate partial (one or more stages) and full deployment of the funnel-shaped sleeve 16.

[0071] The system 10 may also include an actuator 22 for closing the funnel-shaped sleeve 16, for example, after capture of a thrombus. Such an actuator may include a mechanism for pulling a wire that extends from the actuator 22, through the inner tube 14, to a distal opening 34 of the funnel-shaped sleeve 16. When such a wire is pulled, it may clamp the funnel-shaped sleeve 16 closed.

[0072] The pull wire extends from the proximal end, through the inner catheter (eg, sidewall conduit), through the lumen of the funnel sleeve (in a helical pattern), and is attached to some or all of the wire loop that forms the distal end 31 .

[0073] Closure may be by constriction (e.g., purse-string suture) or by deflection (in the shovel configuration) by pulling the extension at the distal end (the tip of the shovel) towards the base of the shovel. Alternatively, the tip of the shovel may be tilted 10-30 degrees downward to pull and lift the closure wire, thereby changing the height of the shovel, detaching the clot from the vessel wall.

[0074] FIG. 1B shows a handle 23 with a trigger 26 and a mechanism for causing partial deployment of the funnel-shaped sleeve 16 (the state shown in FIGS. 2B, 3B). The mechanism pulls back the outer tube 12 a measured distance upon actuation of the trigger 26. Alternatively, the trigger 26 may be a slider that can be moved to an indentation or marking. The slider configuration of the handle 23 is shown in more detail in FIG. 6A. The trigger 26 is a slider button that can be moved proximally-distally along the housing 27. Such movement pulls the outer tube 12 partially proximally, and then the funnel-shaped sleeve 16 fully uncovers and deploys. An indentation in the housing 27 stops the slider button at preset positions corresponding to a first partial deployment (cone-like shape), a second and optional third partial deployment, and a full deployment.

[0075] System 10 may also include a suction source attached to inner tube 14 via port 35. Such a suction source may be a syringe 28 (FIG. 1C) or a pump that applies a suction pressure of -2 to -12 psi.

[0076] 2A-2C and 3A-C show the deployment of a shovel-shaped (FIGS. 2A-2C) or standard (FIGS. 3A-3C) funnel-shaped sleeve 16 from an outer tube 12. As described hereinabove, the funnel-shaped sleeve 16 is deployed in stages, in a first stage, it is partially deployed to form a cone-like shape. Such deployment can be accomplished by retracting the outer tube 12 or pushing out the inner tube 14, as described hereinabove.

[0077] In the shovel configuration, partial deployment (eg, the tip portion) can be used to facilitate navigation through tortuous blood vessels.

[0078] The shovel configuration of the funnel sleeve 16 is shown in further detail in Figures 2D-E.

[0079] In the embodiment shown in these figures, funnel-shaped sleeve 16 is braided (and optionally covered) with distal wire loops 17 that form leaflets that extend distally to a distal end 31 that is approximately 25%-75% of the circumference of funnel-shaped sleeve 16 and is 1-3 mm longer. The resulting distal end 31 is beveled at an angle (B) that may be 30-80 degrees.

[0080] The wire loop 17 can also be angled outward (flared, FIG. 2D) (over most or all of its circumference) by 120-170 degrees so that the distal end 31 of the funnel-shaped sleeve 16, which defines the opening 34, has a larger diameter (15-60% larger) than the diameter of the lumen of the funnel-shaped sleeve 16 (A). This enhances the ability of the leaflets at the distal end 31 to suck in the clot and form a seal between the distal end 31 of the funnel-shaped sleeve 16 and the vessel wall. This results in higher suction forces, allowing for smoother entry of the clot into the funnel-shaped sleeve 16 and reducing the chance of the artery and funnel-shaped sleeve collapsing.

[0081] 4A-C and 5A-C show the gradual capture of a thrombus 30 lodged within a blood vessel 32. FIG.

[0082] In a first step (FIGS. 4A, 5A), the system 10 is positioned away from or adjacent to the thrombus 30 using standard over-the-wire percutaneous access techniques (wire is placed through the inner tube 14). The funnel sleeve 16 is then partially deployed using the trigger 26 or markings 20 such that the distal opening 34 of the funnel sleeve 16 advances and is positioned against the thrombus 30 (FIGS. 4B, 5B). Suction is then applied through the inner tube 14 to partially internalize / engage the thrombus 30. A small amount of blood is slowly drawn into the syringe, indicating engagement of the thrombus.

[0083] The funnel sleeve 16 is then extended outward while maintaining suction, thereby fully entrapping the thrombus 30. Once fully entrapped, the distal opening 34 of the funnel sleeve 16 is closed (e.g., with a pull wire). The system 10 along with the thrombus 30 can then be retrieved outside the body.

[0084] 4D-F show capture using a standard funnel-shaped sleeve 16 with a capture / closure mechanism comprising a flexible arm 21 at the distal portion of the funnel-shaped sleeve 16. The arm 21 is attached to (or formed with) the braided material of the funnel-shaped sleeve 16 and projects distally at an angle of 16-25° away from the centerline of the funnel-shaped sleeve 16. As material (thrombus) advances toward the opening of the funnel-shaped sleeve 16 (FIG. 4D), it pushes the arm 21 outward (FIG. 4E), thereby allowing the material to move into the funnel-shaped sleeve 16. In this respect, the arm 21 functions as a flexible trap door. Once material is within the proximal portion of the funnel-shaped sleeve, movement toward the distal end pushes the arm 21, effectively blocking the distal opening and preventing release of the material (FIG. 4F).

[0085] The funnel-shaped sleeve 16 and outer tube 12 and / or inner tube 14 may include radiopaque markers 41 (FIG. 2F) to indicate under fluoroscopy the funnel opening and the distance of the distal end 31 from the site of thrombus or occlusion. The radiopaque markers 41 may be, for example, 3-6 gold dots placed on the braided wire near or at the distal end 31 near the periphery. The distance between the imaged radiopaque markers can be used to indicate the extent of the opening of the funnel-shaped sleeve 16 within the vessel.

[0086] The funnel sleeve 16 may also include a sensor or sensor array 43 (at the proximal and distal ends) for detecting the presence of material within the lumen. The sensor 43 may be an impedance sensor such as that described in U.S. Patent Application Publication No. 20190159684.

[0087] The base (proximal) sensor 43 can be used to determine when suction can be stopped as material reaches the tapered base portion of the funnel-shaped sleeve 16. The tip (distal) sensor 43 can be used to determine if material is at the opening of the funnel-shaped sleeve 16 and may be preventing closure.

[0088] The system 10 may also include a pulverizer 24 (FIGS. 9A-9B) for pulverizing the trapped thrombus. The pulverizer 24 may be introduced into the funnel-shaped sleeve 16 through the inner tube 14 (FIG. 9A) and may include a deployable cutter 25 that may include one or more arcuate blades that, upon rotation, pulverize the thrombus material, allowing it to be subsequently collected through the inner tube 14.

[0089] As used herein, the term "about" refers to ±10%.

[0090] Additional objects, advantages, and novel features of the present invention will become apparent to one skilled in the art upon examination of the following examples thereof, which are not intended to be limiting. EXAMPLES

[0091] Reference is now made to the following examples, which together with the above descriptions illustrate the invention in a non-limiting manner.

[0092] Animal testing Testing was performed in a 60 kg female pig using a prototype of the system with a standard or shovel funnel. A clot was generated from the pig's autologous blood to generate a whole blood clot, a 6Fr sheath was used to inject the clot into the target site, and angiograms were performed to confirm vascular occlusion. A femoral access site was used to guide the over-the-wire and microcatheter of the system to the occlusion site in the vessel with the funnel folded into the catheter sheath (outer tube). The marker bands at the funnel tip and outer catheter tip with radiopaque markers were visible under fluoroscopy during guidance (Figure 7A).

[0093] The distal end of the catheter was positioned a few millimeters from the clot, and the microcatheter and guidewire were removed. The funnel was advanced to the distal end of the outer tube, which was then pulled back 2-3 mm, partially deploying the funnel to form a cone (Figure 7B). Suction was applied to pull the outer tube while simultaneously pushing the inner tube attached to the funnel forward to fully deploy the funnel (Figure 7C). The pull wire was used to close the distal opening of the funnel and retracted into the outer tube. The system was then removed along with the clot trapped within the funnel.

[0094] A second study was conducted in a 60 kg female pig using a prototype of the system with a shovel-shaped funnel. A femoral access site was used to guide the over-the-wire and microcatheter of the system to the site of occlusion in the vessel, with the funnel folded into the catheter sheath.

[0095] The distal end of the catheter was positioned a few millimeters from the clot (indicated by a contrast border on the angiogram), and the microcatheter and guidewire were removed (Figure 8A). The funnel was advanced to the distal end of the outer tube, which was then pulled back 2-3 mm, partially deploying the funnel to form a cone (Figure 8B). Suction was applied to pull the outer tube while simultaneously pushing the inner tube attached to the funnel forward to fully deploy the funnel (Figure 8C). The pull wire was used to close the distal opening of the funnel and retracted into the outer tube. The system was then removed along with the clot trapped within the funnel.

[0096] It will be appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination.

[0097] Although the present invention has been described in relation to specific embodiments thereof, it is apparent that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims. All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated herein by reference. Furthermore, citation or identification of a reference in this application should not be construed as an admission that such reference is available as prior art to the present invention.

Claims

1. A catheter system for withdrawing a substance from a biological blood vessel, comprising: an inner tube movable within an outer tube; a braided funnel sleeve attached to the inner tube and configured to transition between a collapsed state when isolated within the outer tube and an expanded state when advanced outside the outer tube; A system in which a distal end portion of the braided funnel sleeve includes leaflets formed by wire, the leaflets extending distally 1-3 mm around 25%-75% of the circumference of the braided funnel sleeve.

2. The system of claim 1 , wherein the leaflets form a shovel-shaped distal extension.

3. The system of claim 1 , wherein the braided funnel sleeve comprises an inner cover.

4. The system of claim 1 , wherein the distal end of the braided funnel sleeve is beveled at an angle of between 30 and 80 degrees.

5. The system of claim 1 , further comprising a pull wire closure mechanism for pinching closed the distal opening.

6. The system of claim 1 , further comprising a plurality of flexible arms disposed on and attached to the braided funnel sleeve.

7. The system of claim 1 , wherein the braided funnel sleeve has an hourglass shape when fully deployed.

8. The system of claim 1 , further comprising a device for disrupting thrombus material trapped within the braided funnel-shaped sleeve.

9. 10. The system of claim 1, further comprising a mechanism or indicator for allowing a user to advance a predetermined length of the braided funnel sleeve portion out of the outer tube.

10. The system of claim 9 , wherein the mechanism is a trigger for causing the advancement of the portion.

11. The system of claim 9 , wherein the indicator includes markings to indicate advancement of the portion.

12. The system of claim 3 , further comprising a conduit for applying suction to an interior volume of the braided funnel-shaped sleeve.

13. The system of claim 12 further comprising a sensor for determining the presence or absence of a substance at the opening of the braided funnel sleeve.

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