Retrieval system and method

Abstract

A catheter system includes an inner tube movable within an outer tube and a 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 pushed out of the outer tube.

Description

Background Technology

[0001] This invention relates to systems and methods for retrieving materials or objects from biological containers. Embodiments of the invention involve catheters with funnel-shaped traps, which are highly effective in capturing and retrieving cerebral emboli / thrombi.

[0002] In recent years, the number of interventional procedures used to treat vascular lesions that are difficult to access through surgical procedures has been increasing.

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

[0004] Cerebral embolism is a vascular disease that occurs when a substance (usually a blood clot) migrates and blocks the blood vessels that supply brain tissue.

[0005] Conventional techniques for retrieving cerebral emboli involve using a retrieval catheter with a funnel-shaped trap for capturing and retrieving the emboli.

[0006] While this retrieval device is effective at retrieving small clots, retrieving large clots can cause the clot to break apart and release potentially harmful clot particles into the bloodstream.

[0007] Therefore, there is still room for improvement in blood clot retrieval systems, especially in the ability of such systems to bind and retract clots. Invention Overview

[0009] According to one aspect of the invention, a catheter system for retrieving material from a biological vessel is provided, comprising: an inner tube movable within an outer tube; a funnel-shaped sleeve attached to the inner tube and configured to switch between a contracted state when isolated within the outer tube and an expanded state when extended from the outer tube; and a mechanism or indicator for enabling a user to extend a portion of the sleeve of a predetermined length from the outer tube.

[0010] According to an embodiment of the invention, the mechanism is a trigger for initiating the advancement of the portion.

[0011] According to an embodiment of the invention, the indicator includes a mark for indicating the advancement of the portion.

[0012] According to an embodiment of the present invention, the sleeve is a braided sleeve.

[0013] According to an embodiment of the invention, the length of the braided sleeve decreases during expansion.

[0014] According to an embodiment of the present invention, the braided sleeve includes a cap.

[0015] According to an embodiment of the present invention, the cover is made of polyurethane, TPU, PTFE or silicone.

[0016] According to an embodiment of the invention, the catheter system further includes a catheter for applying suction within the braided sleeve.

[0017] According to an embodiment of the invention, the catheter system further includes a vacuum source in communication with the catheter.

[0018] According to an embodiment of the invention, a portion of the sleeve of a predetermined length forms a cone when it is pushed out of the outer tube.

[0019] According to an embodiment of the invention, the distal opening of the sleeve includes a closing mechanism.

[0020] According to an embodiment of the present invention, the closing mechanism includes a pull wire.

[0021] According to an embodiment of the present invention, the pull wire is tightened to close the distal opening.

[0022] According to an embodiment of the invention, the wires are arranged such that the material can be separated from the wall of the funnel-shaped sleeve.

[0023] According to an embodiment of the invention, the distal end of the sleeve is inclined, such that the opening of the sleeve forms an inclined ellipse when it expands.

[0024] According to an embodiment of the invention, the funnel-shaped sleeve includes a non-transparent marking strip.

[0025] According to an embodiment of the invention, the braided sleeve includes a loop of yarn located at the distal end.

[0026] According to an embodiment of the present invention, the cover includes a hydrophobic coating.

[0027] According to an embodiment of the invention, the catheter system further includes a catheter for injecting dye.

[0028] According to an embodiment of the invention, the conduit system further includes at least one sensor for identifying the presence of material within the funnel-shaped sleeve.

[0029] According to an embodiment of the invention, the first sensor of at least one sensor is located in the proximal region of the funnel-shaped sleeve.

[0030] According to an embodiment of the invention, the second sensor in at least one sensor is located in the distal region of the funnel-shaped sleeve.

[0031] According to an embodiment of the invention, the catheter system further includes a plurality of flexible arms positioned within and attached to the funnel-shaped sleeve.

[0032] According to an embodiment of the invention, the funnel-shaped sleeve has an hourglass-like shape when fully extended.

[0033] According to another aspect of the invention, a method for retrieving material from a biological vascular bundle is provided, comprising: extending a funnel-shaped sleeve from a portion of a conduit located in the biological vascular bundle to form a cone of predetermined length within the biological vascular bundle; drawing the material from the biological vascular bundle into the cone; and further extending the funnel-shaped sleeve from the conduit and applying the suction force to trap the material within the funnel-shaped sleeve.

[0034] According to an embodiment of the present invention, suction is performed while the conduit is advanced along the direction of the material.

[0035] According to an embodiment of the invention, the method further includes closing the distal end of the funnel-shaped sleeve.

[0036] According to an embodiment of the invention, the catheter is advanced through a biological vascular system after partial deployment.

[0037] According to another aspect of the invention, a catheter system for retrieving material from a biological vessel is provided, comprising: an inner tube movable within an outer tube; a funnel-shaped sleeve attached to the inner tube and configured to switch between a contracted state when isolated within the outer tube and an expanded state when extended from the outer tube; and a plurality of flexible arms positioned within and attached to the funnel-shaped sleeve, the plurality of flexible arms being configured to allow material to enter the funnel-shaped sleeve while preventing the material from being released from the funnel-shaped sleeve.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While similar or equivalent methods and materials to those described herein may be used in the practice or testing of this invention, suitable methods and materials are described below. In case of conflict, the patent specification (including definitions) shall prevail. Furthermore, materials, methods, and embodiments are illustrative only and not restrictive. Attached Figure Description

[0039] The invention is described herein by way of example only and with reference to the accompanying drawings. Reference is now made specifically to the drawings, with emphasis placed on the details shown, which are by way of example and for the purpose of illustrative discussion of preferred embodiments of the invention only, and are presented to provide a description that is considered most useful and readily understood of the principles and concepts of the invention. In this regard, no attempt is made to show the structural details of the invention in more detail than necessary for a basic understanding of the invention, and the description, taken in conjunction with the drawings, makes it clear to those skilled in the art how various forms of the invention can be embodied in practice.

[0040] In the diagram:

[0041] Figure 1A-1F The illustration shows an implementation scheme for this catheter system, including a shovel-shaped funnel ( Figure 1A , Figure 1D-1F ), standard funnel ( Figure 1B ), trigger release handle ( Figure 1A-1B ) and the marked handle ( Figure 1C ).

[0042] Figure 2A-2C The diagram illustrates the two-stage development of the shovel-funnel conduit structure.

[0043] Figure 2D-2E The shovel-shaped structure is illustrated in more detail, showing the leaflets formed by loops of metal wire.

[0044] Figures 3A-3C The diagram illustrates the two-stage development of a standard funnel-shaped conduit.

[0045] Figures 4A-4C The illustration shows clot capture using a shovel-funnel conduit construction.

[0046] Figure 4D-4F The illustration shows clot capture using a shovel-funnel conduit construction with a flexible arm.

[0047] Figures 5A-5C The illustration shows clot capture using a standard funnel conduit.

[0048] Figures 6A-6B The illustration shows the trigger handle for a partially unfolding shovel or standard funnel. Figure 6A ) and tags ( Figure 6B ).

[0049] Figures 7A-7C Fluorescent images of clots were captured in a pig model using this catheter system equipped with a standard funnel.

[0050] Figures 8A-8B Fluorescent images of clots were captured in a pig model using the catheter system equipped with a shovel-shaped funnel according to the present invention.

[0051] Figure 8C Through Figures 8A-8B The image shown is of the clotted material retrieved by the procedure. Invention Details

[0053] This invention relates to a catheter system and method for retrieving materials / objects (e.g., emboli) from biological vessels (e.g., blood vessels).

[0054] The principles and operation of the invention can be better understood by referring to the accompanying drawings and description.

[0055] Before explaining at least one embodiment of the invention in detail, it should be understood that the application of the invention is not limited to the details set forth in the following description or illustrated by examples. The invention can have other embodiments or can be practiced or performed in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting.

[0056] Mechanical thrombectomy devices that utilize a trap to retrieve clotted material are well known in the art. Such a trap may include a closable distal opening for retaining the retrieved clotted material within a sleeve while minimizing the release of clotted material or fragments from the trap when it is pulled out of the vascular system.

[0057] In a previously filed patent application (WO2019064306), the inventors disclosed a unique collector closure mechanism that significantly enhances the retrieval of the entire clot. While putting this invention into practice, the inventors set out to improve clot collection capabilities, particularly in the case of large clots.

[0058] Therefore, according to one aspect of the invention, a catheter system for retrieving materials or objects from biological vessels is provided.

[0059] As used in this article, the term "material" refers to biological materials, such as biological materials characterizing thrombi / emboli, while the term "object" refers to implants, such as stents, stent grafts, etc.

[0060] This system can be used to access and treat any biological blood vessels, including vessels of the circulatory system (e.g., arteries, veins, lymphatic vessels), vessels of the urinary tract (e.g., urethra, ureter), and vessels of the lymphatic system.

[0061] The system of the present invention includes a funnel-shaped sleeve configured to switch between a contracted state and an expanded state. When in the expanded state, the funnel-shaped sleeve is shaped like a funnel whose diameter gradually tapers from distal to proximal. The funnel includes an inner lumen accessible through a distal opening, which may be circular and perpendicular to the longitudinal axis of the catheter (also referred to herein as the "standard configuration") or elliptical and inclined / angled relative to the longitudinal axis of the catheter (also referred to herein as the "shovel configuration").

[0062] When contracted, the funnel-shaped sleeve is a narrow cylinder with a small inner lumen (large enough to insert a guidewire and / or microcatheter). The funnel-shaped sleeve can be self-expanding, in which case at least a portion of it will self-expand to a final diameter that is limited by the diameter of the blood vessel (and up to the diameter limited by the braided structure and the extent to which it unfolds from the catheter sheath).

[0063] According to one embodiment of the invention, the funnel-shaped sleeve may be made of metal (e.g., stainless steel or nickel-titanium alloy (NITINOL)) or polymer (e.g., PTFE) threads woven in alternating helical and anti-helical directions. The braid may be (completely or partially) covered with a polymer such as TPU or polyurethane to allow a vacuum to be applied to the internal volume of the funnel-shaped sleeve.

[0064] The diameter of the thread can be between 0.02-0.25 mm, while the weaving angle between the threads can be between 60-140 degrees. The funnel-shaped sleeve can be manufactured using a mandrel of suitable size by winding the thread in an alternating spiral pattern. For example, a single thread can be wound into a loop, and the end of the loop can be wound around the mandrel in a spiral pattern to form a cross pattern (1x1 pattern) in each thread or a cross pattern (2x1 pattern) every two threads along the length of the mandrel. Multiple threads (12-64) can be used to form a braided structure. Small-diameter braided structures with the same pattern (…) Figure 1G This type of braid has advantages in certain constructions because it increases the radial force of the funnel, thus preventing collapse under suction. An example of such a braid is provided in WO2019064306. The funnel-shaped sleeve may include loops (around the opening of the expanding funnel-shaped sleeve) at its distal end. When the funnel-shaped sleeve contacts the clot, the loops form lobes that provide axial support and reduce fabric compression (thus minimizing the accordion effect that may occur when the braided structure is pushed towards the clot). The loops also form soft ends to minimize vascular damage during unfolding. During suction, these lobes collapse around and encase the clot without causing the braided structure to collapse.

[0065] The parameters and dimensions of the catheter and funnel-shaped sleeve depend on the intended use and type of blood vessel. When used for ischemic stroke in intracranial arteries, the target artery size may vary between 2.5 and 4.5 mm. The diameter of the funnel-shaped sleeve should be at least slightly larger than the diameter of the blood vessel to impede blood flow, thus ranging from 2 to 7 mm. The length of the funnel-shaped sleeve can be long enough to support the reception of long clots within the lumen, but also short enough to allow deployment by pushing the funnel-shaped sleeve out of the catheter cannula or by pulling in the sheath.

[0066] The system also includes a catheter for delivering the funnel-shaped sleeve into a blood vessel. According to one embodiment of the invention, the funnel-shaped sleeve may be attached to the distal end of the inner tube (shaft) of the catheter and is covered by a removable sheath (outer tube) when in a contracted configuration. Removing (pulling along the proximal direction) of the sheath unfolds the funnel-shaped sleeve.

[0067] In another embodiment of the invention, the funnel-shaped sleeve is captured in the inner lumen of the outer tube of the catheter in a contracted state and is extended by an inner tube attached to the proximal end of the funnel-shaped sleeve.

[0068] This catheter system may also include a suction source (e.g., a syringe, a pump) that applies suction force to the inner cavity (internal volume) of the funnel-shaped sleeve via a dedicated conduit that fluidly connects the suction source to the inner cavity of the funnel-shaped sleeve. The inner tube of the catheter can also serve as a fluid conduit.

[0069] Experiments conducted by the inventors have shown that when suction is applied to the inner cavity of the funnel-shaped sleeve, the distal opening of the fully extended funnel-shaped sleeve can sometimes be blocked by large blood clots. This blockage can cause the funnel-shaped sleeve to collapse during suction.

[0070] The inventors have discovered that the partial unfolding of the funnel-shaped sleeve, allowing a 2-8 mm long cone to extend from the catheter or remain unexposed by the sheath, significantly enhances the system's ability to collect thrombus material without clogging or collapse. Therefore, the inventors have devised a method in which the conical portion of the funnel-shaped sleeve first unfolds (at the thrombus or unfolded and advanced to the thrombus), the thrombus is engaged and drawn into this portion, and then the remaining portion of the funnel-shaped sleeve gradually unfolds while maintaining suction to completely engulf and capture the thrombus.

[0071] In this way, the system draws out blood clots and increases the volume of the funnel as the clots are engulfed.

[0072] To achieve this functionality, the catheter system includes a mechanism or indicator that allows the funnel-shaped sleeve portion to unfold. This mechanism may include a trigger for precisely unfolding the funnel-shaped sleeve portion or an indicator with markings that allow the user to unfold a specific length of the funnel-shaped sleeve portion.

[0073] Now refer to the attached diagram, Figure 1A-1D The catheter system of the present invention is illustrated, and is referred to below as system 10.

[0074] System 10 includes a catheter shaft, which includes an outer tube 12 surrounding an inner tube 14. The inner tube 14 is attached to a funnel-shaped sleeve 16 (shown in the image). Figure 1A-1C (Expanded), this funnel-shaped sleeve is used to capture (within the lumen) and retrieve material or objects from biological vessels (such as arteries). The funnel-shaped sleeve 16 includes a distal opening 34 and an inner lumen 33, and can be one of two types, namely a shovel-shaped funnel-shaped sleeve 16 (…). Figure 1A , 1C ID) or standard funnel-shaped sleeve 16 ( Figure 1B ).

[0075] The inner tube 14 can be an elongated hollow tube, the length, diameter, and flexibility of which are selected to suit the intended treatment location. Different anatomical locations will require inner tubes 14 with different stiffness and axial flexibility. Inner tubes 14 with variable stiffness and axial flexibility along their axial length are well known in the art and can be braided or coiled with an inner coating of a low-friction material such as PTFE, a metal braid or coil on the inner layer, and an outer polymer layer (outer jacket), such as PEBAX or polyamide composites with various hardness grades. Such tubes are typically used for delivery into tortuous vascular systems or intracranial vascular systems.

[0076] The outer tube 12 may be a long, thin, hollow tube that can slide on the inner tube 14. The length of the inner tube 14 may be shorter than that of the outer tube 12 and the outer tube 12 may be pulled back to partially and fully unfold the funnel-shaped sleeve 16.

[0077] The length, diameter, and flexibility of the outer tube 12 are selected to suit the intended treatment location. The requirements for high distal flexibility and tracking performance are achieved by selecting a soft material jacket and a metal coil design. The outer tube 12 can have different stiffness and axial flexibility, as well as proximal stiffness and maneuverability, for delivery through 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 with an inner polymer layer (e.g., PTFE) having a low-friction layer, metal braids and coils in different sections of the inner layer, and an outer polymer layer (jacket), such as PEBAX, polyurethane, or polyamide composites with various hardness grades.

[0078] The outer diameter of the inner tube 14 can be 0.5-4 mm (e.g., 1.5 mm), while the inner diameter of the inner tube 14 (which can be used as an aspiration catheter) can be 0.3-3.5 mm. The lumen (for closure) can be separate from the inner lumen and its diameter can be 0.03-0.3 mm (it can be positioned within the wall of the inner tube 14). The length of the inner tube 14 can be in any range between 50-150 cm and is selected according to the target blood vessel and treatment location.

[0079] The outer diameter of the outer tube 12 can be 1-6 mm, while the inner diameter of the outer tube 12 (which houses the inner tube 14) can be 0.8-5.5 mm. The length of the outer tube 12 can be in any range between 45-145 cm and can be selected according to the target blood vessel and treatment location.

[0080] The length of the funnel-shaped sleeve 16 can be 5-80 mm, and when fully extended, its diameter gradually tapers from 1-20 mm (distal end) to 0.3-18 mm (proximal end), and when isolated within the outer tube 12, its diameter gradually tapers to 10-160 mm. The funnel-shaped sleeve 16 (standard or shovel-shaped) can also have an hourglass shape when extended. Figure 1DThe hourglass shape is advantageous because, due to Bernoulli's principle, the diameter difference between the two regions of the funnel-shaped sleeve 16 (labeled R1 and R2, proximal and distal, respectively) creates a pressure difference between the funnel segments (proximal and distal), thus facilitating the pushing of material towards the proximal region (R1). Another advantage is that the proximal region (R1) can trap and retain thrombi and prevent their release because of its smaller diameter. Figure 1F (collapsed onto the material).

[0081] Funnel-shaped sleeve 16 shape ( Figure 1G The advantage of the hourglass shape is that the narrowing area (e.g., the transition from R2 to R1) will increase the PPI (pitch per inch), which will increase the stiffness of the funnel and thus prevent it from collapsing under suction.

[0082] The funnel-shaped sleeve 16 can be unfolded by using the handle 18 attached to the outer tube 12. Figure 1A This is achieved by pulling the outer tube 12 back (towards the proximal side) or by pushing the inner tube 14 out (towards the distal side) against the handle 18. Mark 20 can be used to determine the length of the unfolded funnel-shaped sleeve 16. This mark can be used for partial unfolding of the funnel-shaped sleeve 16 to form a cone shape of a predetermined length. Figure 2B , 3B ).

[0083] Figure 6B A handle 18, which can move with the outer tube 12 to partially and then fully unfold the funnel-shaped sleeve 16, is shown in more detail. The handle 18 includes a button 19 for releasing / locking movement of the outer tube 12 relative to the inner tube 14. A mark 20 on the inner tube 14 indicates the partial unfolding (one or more stages) and full unfolding of the funnel-shaped sleeve 16.

[0084] System 10 may also include an actuator 22 for closing the funnel-shaped sleeve 16 after, for example, thrombus occlusion. This actuator may include a mechanism for pulling a line extending from the actuator 22 through the inner tube 14 to the distal opening 34 of the funnel-shaped sleeve 16. When this line is pulled, it can tighten the closed funnel-shaped sleeve 16.

[0085] The suture extends from the proximal end through the internal catheter (e.g., a sidewall catheter), through the lumen of the funnel-shaped sleeve (in a spiral pattern), and attaches to some or all of the suture loops forming the distal end 31.

[0086] Closure can be achieved by pulling the distal (shovel tip) extension toward the bottom of the shovel, either by tightening (e.g., with a purse-string) or by deflection (in a shovel-shaped structure). Alternatively, the shovel tip can be tilted downwards by 10–30 degrees, changing the height of the shovel by pulling the closure line and lifting it, thereby separating the thrombus from the vessel wall.

[0087] Figure 1BThe illustration shows a handle 23, which includes a trigger 26 and a portion for triggering the unfolding (towards) of the funnel-shaped sleeve 16. Figure 2B , Figure 3B The mechanism (as shown in the diagram) pulls the outer tube 12 back by the measured distance when the trigger 26 is actuated. Alternatively, the trigger 26 may be a slider movable to a dent or mark. Figure 6A The slider mechanism of handle 23 is shown in more detail. Trigger 26 is a slider button that can move proximally and distally along housing 27. This movement pulls outer tube 12 proximally to partially, and then fully exposes and unfolds funnel-shaped sleeve 16. Indentations in housing 27 stop the slider button at preset positions corresponding to the first partial unfolding (conical shape), the second and optional third partial unfolding, and the full unfolding.

[0088] System 10 may also include a suction source attached to inner tube 14 via port 35. Such a suction source may be syringe 28. Figure 1C Or a pump that applies a suction pressure of -2 to -12 psi.

[0089] Figure 2A -C and Figure 3A -C illustrates the shovel-shaped ( Figure 2A -C) or standard ( Figure 3A -C) The funnel-shaped sleeve 16 unfolds from the outer tube 12. As described above, the funnel-shaped sleeve 16 unfolds in stages, wherein in the first step it is partially unfolded to form a conical shape. This unfolding can be achieved by pulling in the outer tube 12 or pushing out the inner tube 14, as described above.

[0090] In a shovel construction, partial expansion (e.g., the end portion) can be used to facilitate navigation through tortuous blood vessels.

[0091] The shovel-shaped structure of the funnel-shaped sleeve 16 is in Figure 2D The details are shown in -E.

[0092] In the embodiments shown in these figures, the funnel-shaped sleeve 16 is woven (and optionally covered) and includes a distal loop 17 forming a leaflet, the leaflet extending distally to extend the distal end 31 by 1-3 mm, approximately 25%-75% of the circumference of the funnel-shaped sleeve 16. The resulting distal end 31 is tilted at an angle (B) that can be 30-80 degrees.

[0093] The loop 17 can also be tilted outwards (A) (opening). Figure 2DThe angle of the funnel-shaped sleeve 16 (120-170 degrees, around most or all of the circumference) is such that the diameter of the distal end 31 of the funnel-shaped sleeve 16 defining the opening 34 is larger than the lumen of the funnel-shaped sleeve 16 (15-60% larger). This enhances the ability of the lobules of the distal end 31 to engulf the thrombus and form a seal between the distal end 31 of the funnel-shaped sleeve 16 and the vessel wall. This results in higher suction, smoother clot entry into the funnel-shaped sleeve 16, and a reduced chance of arterial and funnel-shaped sleeve collapse.

[0094] Figures 4A-4C Figures 5A-5C illustrate the stepwise capture of thrombus 30 residing in blood vessel 32.

[0095] In the first step ( Figure 4A , 5A In this process, system 10 uses a standard in-line, percutaneous access technique (the suture passes through the inner tube 14 for positioning) to locate at or near the thrombus 30. Then, trigger 26 or marker 20 is used to partially unfold the funnel-shaped sleeve 16, and the distal opening 34 of the funnel-shaped sleeve 16 is advanced and positioned against the thrombus 30. Figure 4B , Figure 5B Then, aspiration is applied through inner tube 14 to partially internalize / bind the thrombus 30. A small amount of blood is slowly drawn into the syringe to indicate thrombus binding.

[0096] The funnel-shaped sleeve 16 then extends while maintaining suction, thereby completely internalizing the thrombus 30. Once fully internalized, the distal opening 34 of the funnel-shaped sleeve 16 closes (e.g., with a pull wire). The system 10 can then be removed from the body along with the thrombus 30.

[0097] Figure 4D-4F The illustration depicts a capture using a standard funnel-shaped sleeve 16, which has a capture / closure mechanism comprising a flexible arm 21 located at the distal portion of the funnel-shaped sleeve 16. The arm 21 is attached to (or formed with) the woven material of the funnel-shaped sleeve 16 and protrudes distally at an angle of 16-25° away from the centerline of the funnel-shaped sleeve 16. When material (thrombus) advances toward the opening of the funnel-shaped sleeve 16 ( Figure 4D It pushes arm 21 outward. Figure 4E This allows material to move into the funnel-shaped sleeve 16. In this respect, arm 21 acts as a flexible trapdoor. Once the material is within the proximal portion of the funnel-shaped sleeve, any movement toward the distal end will push arm 21 to effectively block the distal opening and prevent material release. Figure 4F ).

[0098] The funnel-shaped sleeve 16 and the outer tube 12 and / or the inner tube 14 may include a radiopaque marking 41. Figure 2FThe radiopaque markers 41 are used to indicate the opening of the funnel under fluorescence examination, and the distance of the distal end 31 from the site of thrombus or occlusion. The radiopaque markers 41 can be, for example, 3-6 gold dots located near or at the distal end 31 on a woven line surrounding the circumference. The distance between the radiopaque markers on the imaging can be used to indicate the degree of opening of the funnel-shaped sleeve 16 in the blood vessel.

[0099] The funnel-shaped sleeve 16 may also include sensors or sensor arrays 43 (at the proximal and distal ends) for detecting the presence of material within the cavity. Sensor 43 may be an impedance sensor, such as those described in US20190159684.

[0100] The base (proximal) sensor 43 can be used to determine when suction can be stopped when material reaches the conical base of the funnel-shaped sleeve 16. The end (distal) sensor 43 can be used to determine whether material is at the opening of the funnel-shaped sleeve 16, which may interfere with closure.

[0101] System 10 may also include an immersion softener 24 for softening the captured thrombus. Figure 9A -B). The softener 24 can pass through the inner tube 14 ( Figure 9A The material is introduced into the funnel-shaped sleeve 16 and may include an expandable cutter 25, which may include one or more bow-shaped blades that, when rotated, soften the thrombus material and allow subsequent collection of the thrombus material through the inner tube 14.

[0102] As used in this article, the term “about” means ±10%.

[0103] Other objects, advantages and novel features of the invention will become apparent to those skilled in the art upon examining the following embodiments, which are not intended to be limiting. Example

[0104] The invention is now described in a non-limiting manner with reference to the following embodiments, which together with the above description.

[0105] animal testing

[0106] The prototype of this system, equipped with a standard funnel or a shovel-shaped funnel, was tested on 60 kg sows. Clots were prepared from the pig's autologous blood to generate whole blood thrombi. The thrombi were injected into the target site using a 6Fr sheath, and angiography was performed to verify vascular occlusion. The femoral access site was used to navigate the system to the occlusion site in the blood vessel via a lead and microcatheter, with the funnel collapsing within the catheter sheath (outer tube). During navigation, the funnel tip with radiopaque markings and the marking band on the outer tube tip were visible under a fluorescence microscope. Figure 7A ).

[0107] A few millimeters from the distal end of the catheter to the clot, the microcatheter and guidewire are removed. The funnel is advanced to the distal edge of the outer tube, which is then pulled back 2-3 millimeters, partially unfolding the funnel to form a cone. Figure 7B Apply suction and pull the outer tube while simultaneously pushing the inner tube attached to the funnel forward to fully expand the funnel. Figure 7C Use a pull wire to close the distal opening of the funnel, and the distal opening retracts into the outer tube. Then remove the system along with the clots collected in the funnel.

[0108] A second trial was conducted on a 60 kg sow using a prototype of the system with a shovel-shaped funnel. The femoral access site was used to navigate the system to the occlusion site in the blood vessel via a wire and microcatheter, with the funnel collapsing within the catheter sheath (outer tube).

[0109] The distal end of the catheter is positioned a few millimeters from the clot (indicated by the contrast boundary from angiography), and the microcatheter and guidewire are removed. Figure 8A The funnel is pushed to the distal edge of the outer tube, which is then pulled back 2-3 mm, partially unfolding the funnel to form a cone. Figure 8B Apply suction and pull the outer tube while simultaneously pushing the inner tube attached to the funnel forward to fully expand the funnel. Figure 8C Use a pull wire to close the distal opening of the funnel, and the distal opening retracts into the outer tube. Then remove the system along with the clots collected in the funnel.

[0110] It should be understood that, for clarity, certain features of the invention described in the context of individual embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, various features of the invention described in the context of individual embodiments may also be provided individually or in any suitable sub-combination.

[0111] Although the invention has been described in conjunction with its specific embodiments, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be readily apparent. Therefore, it is intended to cover all such alternatives, modifications, and variations falling 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 extent that each individual publication, patent, or patent application is specifically and individually indicated to be incorporated herein by reference. Furthermore, any reference or designation to any reference in this application should not be construed as an admission that such reference is prior art to the invention.

Claims

1. A catheter system for retrieving material from biological vessels, comprising: An inner tube that can move inside an outer tube; And a woven funnel-shaped sleeve, the woven funnel-shaped sleeve being attached to the inner tube and configured to switch between a contracted state when isolated within the outer tube and an expanded state when extended from the outer tube, wherein the distal portion of the woven funnel-shaped sleeve includes leaflets formed of thread extending distally, and wherein the leaflets extend distally by 1-3 mm around 25%-75% of the circumference of the woven funnel-shaped sleeve.

2. The system as claimed in claim 1, wherein, The leaflets form a shovel-shaped distal extension.

3. The system as described in claim 1, wherein, The woven funnel-shaped sleeve includes a cap.

4. The system as claimed in claim 1, wherein, The distal end of the woven funnel-shaped sleeve is inclined at an angle of 30-80 degrees.

5. The catheter system of claim 1, further comprising a draw-wire closure mechanism for tightening and closing the distal opening of the braided funnel-shaped sleeve.

6. The catheter system of claim 1, further comprising a plurality of flexible arms positioned within and attached to the braided funnel-shaped sleeve.

7. The catheter system of claim 1, wherein, The woven funnel-shaped sleeve has an hourglass shape when fully unfolded.

8. The catheter system of claim 1, further comprising means for impregnating and trapping thrombus material within the braided funnel-shaped sleeve.

9. The system of claim 1, further comprising a mechanism or indicator for enabling a user to push a portion of the braided funnel-shaped sleeve of a predetermined length out of the outer tube.

10. The system of claim 9, wherein, The mechanism is a trigger used to initiate the advancement of a portion of the woven funnel-shaped sleeve of the predetermined length.

11. The system of claim 9, wherein, The indicator includes a mark for indicating the advancement of a portion of the woven funnel-shaped sleeve of the predetermined length.

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

13. The system of claim 12, wherein the sensor is used to determine whether material is present at the opening of the woven funnel-shaped sleeve.

Images