Catheter orifice design

Abstract

This invention is entitled "Catheter Orifice Design". It discloses an expandable orifice for a catheter that can locally restrict flow and provide a large orifice opening with sufficient radial force while having the flexibility to reach and retrieve occluded clots. The expandable orifice may have a frame with a collapsed state, allowing the clot retrieval catheter to be compatible with a thin external catheter, and an expanded state for contacting the vessel wall and sealing or restricting proximal flow. The frame may have one or more support arms and a distal support clamp, which may have narrowed sections, undulations, obturators, and other flexible reinforcing features. Alternatively, the frame may be a grid with an array of obturators. The expandable orifice may be characterized by a membrane covering disposed around the support frame. These improvements allow for safe and rapid access to complex areas and more reliable removal of occluders while reducing procedure time.

Description

Technical Field

[0001] This disclosure relates throughout to apparatus and methods for removing acute blockages from blood vessels during endovascular medical treatment. More specifically, this disclosure relates to an expandable tip for retrieving an aspiration catheter. Background Technology

[0002] In patients with conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE), aspiration and clot retrieval of catheters and devices are used in mechanical thrombectomy targeting endovascular intervention. Accessing the neurovascular bed using conventional techniques is particularly challenging because the target vessel is small in diameter, distal relative to the insertion site, and highly tortuous.

[0003] When delivering effective devices to the smaller and highly branched cerebral arterial system, conventional catheters must attempt to balance many factors. The catheter must be flexible enough to navigate the vascular system and withstand high flexural strain, while also possessing axial stiffness to provide smooth and consistent advance along the route. Furthermore, sudden changes in stiffness or geometry can impede trackability, introduce significant stress concentrations, and increase the likelihood of device kinking or buckling.

[0004] Some designs for clot retrieval catheters, such as those with a fixed orifice, may struggle to direct the full suction force to the volume of fluid and clot distal to the orifice. When aspiration is performed with a catheter that cannot seal to the target vessel, a significant portion of the aspiration flow ends up from the proximal vessel fluid at the catheter tip, opposite to the distal vessel region containing the clot. This significantly reduces aspiration efficiency and the success rate of clot removal. Furthermore, tight, fibrin-rich clots are often difficult to extract because they can aggregate at the tip of conventional fixed-orifice catheters. This aggregation can lead to the shearing off of softer portions from the tighter areas of the clot.

[0005] The design of catheters used for aspiration, characterized by larger or expandable orifices to improve efficiency, must balance delivery flexibility with sufficient radial force and ablation-free deployment. The catheter elements must withstand the severe mechanical strain imparted by the orifice and generate sufficient radial force upon expansion to prevent collapse during aspiration. To meet these requirements, some aspiration catheters are designed with orifices significantly larger in diameter than typical delivery catheters or sheaths. These designs may not effectively balance the competing requirements to be truly effective and safe for a wide variety of surgical conditions.

[0006] The present invention is designed to provide an improved retrieval catheter with an expandable end, which incorporates features to address the aforementioned deficiencies. Summary of the Invention

[0007] The design described herein can be used for the expandable distal tip of a clot retrieval catheter that provides localized flow restriction / blockage within the target vessel using a large, clot-facing orifice. The catheter can be flexible enough to navigate highly tortuous areas of anatomy (such as neurovascular structures) to reach the occluded clot. The expandable tip is also compatible with relatively low-profile access sheaths and catheters for delivery advantages.

[0008] Clot retrieval catheters may have a substantially tubular support tube defining a longitudinal axis. A large central catheter lumen may be configured to allow guidewires, microcatheters, stent retrieval devices, and other such devices to pass through. The lumen may also guide aspiration to the catheter tip. The tubular body may terminate at a distal end, where an expandable tip may be integrally formed or fixedly attached.

[0009] The catheter may have a self-expanding ostial frame with multiple interconnected struts formed as a porous frame. The ostial frame can be configured to expand from a collapsed delivery configuration to an expanded deployment configuration when deployed at the site of an occluded thrombus. In the expanded deployment configuration, the distal end may be substantially conical or funnel-shaped. The funnel-shaped shape formed by this distal end improves aspiration efficiency, prevents unwanted flow, and reduces the risk of vascular trauma hooking onto the vascular ostium.

[0010] In the deployed state, the expandable tip is tapered, such that the proximal end of the tip has a first radial dimension, and the more distal portion of the tip has a second radial dimension greater than the first radial dimension. The second radial dimension may be greater than the diameter of the target vessel. At least a portion of the tip may have a radial dimension greater than the inner diameter of the external catheter in the expanded deployment configuration.

[0011] In another example, at least a portion of the struts forming the periphery of the oral frame may extend radially inward in the distal direction from the maximum peak radial dimension of the oral frame, such that the maximum radial dimension occurs at an axial position midway between the proximal and distal ends of the frame. This configuration allows the distal end to contact the vessel wall with a large and gentle radius in the expanded state, thereby avoiding vascular trauma and reducing friction. When expanded and unrestrained, the diameter of the distal frame may range from 1 mm to 10 mm, and preferably is closer to 3 mm.

[0012] The mouth support frame can be a patterned sheet or tubular stainless steel or a superelastic shape memory alloy (such as nitinol). The supports of the mouth frame can be connected to form closed-hole, ring, or undulating patterns. Multiple distal hoops or coronal supports can form the circumferential periphery of the terminal mouth opening. One or more support arm supports can extend longitudinally between the proximal and distal ends of the mouth frame to connect adjacent hoops, which intersect at hoop grooves, and the support arms can extend proximally from the hoop grooves to connect the expandable end to the support tube and form a substantially tapered surface around the longitudinal axis.

[0013] The tube body may be characterized by a combination of ribs and ridges to define a substantially tubular shape. An expandable orifice may be integrally formed with the support tube for use in an integral structure, such as by machining the tube and orifice together from the same thiourea tube material. In another example, the tubular body may have a metal or polymer braid / net or a coiled wire construction.

[0014] The support arms may be axisymmetric with respect to the longitudinal axis of the conduit, or they may be twisted or helically positioned about the axis. A single support arm may be independently attached to the most distal rib, or it may extend from or align with one of the axial ridges of the support tube. Alternatively, some of the support arms may be connected via slots, eyelets, or other non-rigid connections, so that the arms do not increase the stiffness of the strut frame.

[0015] The struts of the hoop and support arm may also include features such as narrowing sections, bends, and / or undulations to enhance or adjust the flexibility of the structure. The support arm may take a wavy or sinusoidal pattern circumferentially to allow for greater bending freedom along the axis of the arm. In another case, the struts of the support arm may have a portion that is narrower in width than another part of the support arm, or the support arm may have a width different from the width of at least a portion of the distal hoop or crown forming the periphery of the opening.

[0016] The braces of the hoop and the support arms of the mouth frame may intersect at multiple slots located at various axial and timing positions around the longitudinal axis. The number and location of the slot intersections can partially help determine the local stiffness of the frame. For example, a support arm may terminate proximally at a support slot and distally at a hoop slot to form a closed orifice. In one case, adjacent support arms may share one or more units. In another example, a support arm may extend proximally from the intersection with one or more hoops at the hoop slot and terminate at the ridge of the support tube or the most distal rib to form a closed orifice. These orifices can facilitate longitudinal elongation or shortening of the mouth frame under tensile or compressive loads during thrombectomy.

[0017] When the end is in a collapsed delivery configuration, the slots in the frame act as hinges around which the strut frame folds. During expansion, the support arms of the mouth frame can form an angle with the longitudinal axis, which determines the taper rate of the conical funnel shape at the expanded end. For example, this angle can range from approximately 10 degrees to approximately 45 degrees. In another example, the taper can be shallower and the angle between the support arm and the longitudinal axis can be approximately 30 degrees.

[0018] The support structure can be a patterned sheet or tubular stainless steel or a superelastic shape memory alloy (such as nitinol). The funnel shape formed by this end improves aspiration efficiency, reduces friction, and minimizes the risk of vascular trauma from hooking onto the vessel opening. The funnel shape also means that, in the deployed state, the expandable end is tapered, such that the proximal end of the end has a first radial dimension, and the more distal portion of the end has a second radial dimension larger than the first radial dimension. The second radial dimension can be larger than the diameter of the target vessel.

[0019] The catheter may also have a radially disposed flexible elastomer cover, such that a sleeve is formed around at least a portion of the support tube and the expandable end of the clot retrieval catheter. The cover may be uniform or may have multiple layers. Alternatively, the cover may be one or more polymer jackets.

[0020] Another expandable orifice for the clot retrieval catheter may have a self-expanding orifice frame arranged around a longitudinal axis. The orifice frame may have a collapsed delivery configuration when delivered to the target site constrained within the external catheter, and an expanded deployment configuration when the external catheter retracts to expose the frame. The orifice frame may have multiple interconnected struts, and the struts may form a petal shape arranged circumferentially around the longitudinal axis. Each petal may have a longitudinal arm strut, which is shaped similarly to the aforementioned support arms. The petal may have undulations or a variable width with narrowing sections to enhance flexibility. These features facilitate bending and deflection along the axis of each arm. The longitudinal arms may extend individually, or one or more longitudinal arm struts may split to form one or more closed orifices connected by distal clamps. These orifices allow the petals to elongate independently to avoid pulling the orifice frame proximally during clot retraction.

[0021] The polymer membrane or cover can be positioned above, around, or enclose the ostial frame to provide support to the membrane as suction is directed through the catheter during thrombectomy. The cover can be taut, allowing it to expand under radial forces from the ostial frame when the distal end expands to the deployment configuration, or it can be loose or droopy, allowing all radial forces to be directed to the vessel wall.

[0022] By connecting longitudinal support arms proximally at the groove, connecting struts, sharing a ridge, or individually connecting the longitudinal support arms to the distal rib of the catheter support tube, the valves of the self-expanding ostial frame can be made more flexible. The distal peak of each valve can be a coronal or hoop member that is not circumferentially connected to the coronal of adjacent valves, allowing each valve to eject independently from one or more of its proximal connectors. Therefore, the valves can respond separately to forces and clot morphology, allowing each valve to flex independently without being constrained by adjacent valves.

[0023] In another example, the expandable orifice of the clot retrieval catheter may have a proximal end, a distal end, and a radial strand array forming a closed-cell mesh arranged around a longitudinal axis and extending from the proximal end to the distal end. The mesh array may be made of wire or shape memory alloy, allowing the orifice to expand from a collapsed delivery configuration to an enlarged deployment configuration. When not constrained by an external catheter in the enlarged deployment configuration, the mesh may form a substantially tapered surface around the longitudinal axis. Similar to other examples, a flexible polymer membrane may cover some or all of the closed-cell mesh at the catheter tip.

[0024] The obturator grid array of the ostial frame can be a continuous polygonal pattern, such as triangular or quadrilateral units interlocked by the vertices of adjacent units. This pattern can be one of the patterns commonly seen in stent applications, where a minimally invasive grid is used to support and maintain open vascular access. In one case, an elongated quadrilateral pattern forms unit holes, where local array peaks mark shared vertices. This pattern can be repeated axially and radially, and the most distal array peaks of adjacent holes can be connected by a curved distal clamp or coronal joint to mark the periphery of the expandable ostium.

[0025] The density of the closed-pore mesh pattern can vary. A denser mesh can have greater stiffness and radial force, but also provides more support for the stacked cover or membrane. In one example, the pattern can be dense enough that blood flow through the mesh is impeded by small-sized pores. In this case, a membrane cover may not be necessary because the pattern of pores is small enough to act as a seal, thereby blocking blood from the proximal vessels at the ends.

[0026] To allow for smooth delivery of clots and catheter retrieval via an external catheter, the outer surface of the end-capsule mesh and / or membrane or outer jacket may be coated with a low-friction material, such as PTFE or FEP, or a hydrophilic lubricant, such as those supplied by Surmodics, DSM, and Harland Medical. The coating prevents the buildup of static or dynamic friction, thereby reducing the risk of catheter binding or kinking in tortuous areas of the blood vessel.

[0027] Other aspects and features of this disclosure will become apparent to those skilled in the art after viewing the following detailed description in conjunction with the accompanying drawings. Attached Figure Description

[0028] The foregoing and other aspects of the invention will be further discussed with reference to the following description and the accompanying drawings, in which similar reference numerals indicate elements that function similarly or identically. The drawings are not necessarily drawn to scale; rather, the emphasis is on illustrating the principles of the invention. The drawings depict one or more specific embodiments of the device of the invention by way of example only and not by way of limitation.

[0029] Figure 1 An isometric view of the catheter support tube and expandable distal end according to various aspects of the present invention;

[0030] Figure 2 The distal end of the catheter is shown during the process of retrieving a clot from a target site in a blood vessel, according to various aspects of the present invention.

[0031] Figures 3A to 3D An isometric view and a profile view of an exemplary expandable end according to various aspects of the invention are shown;

[0032] Figures 4A to 4D A view of another expandable end according to various aspects of the invention is shown;

[0033] Figures 5A to 5D A view of another exemplary expandable end according to various aspects of the invention;

[0034] Figures 6A to 6D A view of an alternative expandable end according to various aspects of the invention;

[0035] Figures 7A to 7D A view of another expandable end design according to various aspects of the present invention;

[0036] Figures 8A to 8D Another exemplary expandable end is shown according to various aspects of the invention;

[0037] Figures 9A to 9D A view of an alternative expandable end according to various aspects of the invention;

[0038] Figures 10A to 4D Another expandable end is shown according to various aspects of the invention;

[0039] Figures 11A to 11D Various views for another expandable end design according to various aspects of the present invention;

[0040] Figures 12A to 12D A view of yet another expandable end according to various aspects of the invention;

[0041] Figures 13A to 13DA view of another expandable end according to various aspects of the invention;

[0042] Figures 14A to 14D An alternative expandable end is shown according to various aspects of the invention;

[0043] Figures 15A to 15D A view showing another design of the expandable end according to various aspects of the present invention is shown;

[0044] Figures 16A to 16D A view of another exemplary expandable end according to various aspects of the invention;

[0045] Figures 17A to 17D A view of an alternative expandable end according to various aspects of the invention;

[0046] Figures 18A to 18D A view of another expandable end according to various aspects of the invention is shown;

[0047] Figures 19A to 19C A view of another exemplary expandable end design according to various aspects of the present invention;

[0048] Figure 20 Exemplary expandable ends and conduit support tubes encapsulated in polymer covers according to various aspects of the present invention are shown;

[0049] Figures 21A to 21C Different possibilities for the distal profile of a polymer cover for an expandable end are shown according to various aspects of the invention.

[0050] Figure 22 A view of another example of a polymer cover having a planar surface and a distal rib according to various aspects of the invention;

[0051] Figures 23A to 23D Isometric and profile views of an expandable end having a distal unconnected lobe according to various aspects of the invention are shown.

[0052] Figures 24A to 24D A view of another expandable end according to various aspects of the invention is shown;

[0053] Figures 25A to 25D A view of another exemplary expandable end according to various aspects of the invention;

[0054] Figures 26A to 26D A view of an alternative expandable end design according to various aspects of the invention;

[0055] Figures 27A to 27D A view of another expandable end according to various aspects of the invention is shown;

[0056] Figures 28A to 28D A view of an expandable end with an independent longitudinal arm according to various aspects of the invention;

[0057] Figures 29A to 29C A view of an alternative expandable end according to various aspects of the invention;

[0058] Figures 30A to 30D A view of another expandable end according to various aspects of the invention is shown;

[0059] Figures 31A to 31B A view of an expandable end with a grid structure according to various aspects of the invention is shown. Detailed Implementation

[0060] The purpose of the design disclosed in this invention is to create an expandable orifice for a clot retrieval catheter that provides localized flow restriction / stopping using a large, distally facing orifice tailored to provide sufficient radial force and high flexibility to navigate within an external catheter through the tortuous regions of the vascular system to reach the occluded clot. The large orifice design provides significantly greater aspiration efficiency and flow restriction capability. Such advantages are particularly beneficial in the context of stroke interventional procedures, where the vessels in the neurovascular bed are particularly small, tortuous, and fragile. Therefore, the tailored axial and flexural stiffness distribution of the expandable orifice tip can inhibit kinking and fusion while tracing through these vessels. The tip may have a collapsed state, allowing the clot retrieval catheter to be compatible with relatively low-profile entry sheaths and external catheters, enabling easy and reliable closure of puncture wounds in the patient's groin (in the case of femoral access). The expandable orifice may also feature internal and / or external low-friction lining features, as well as an external polymer jacket or membrane surrounding a support structure. These improvements allow catheters and other devices to enter complex areas more safely and quickly, enabling more reliable removal of obstructions and shorter surgical times.

[0061] Another advantage of using a clot retrieval catheter with a dilated orifice delivered via an external catheter is that once the clot has entered the distal end of the clot retrieval catheter, it can be retracted through the external catheter, leaving the external catheter in place to maintain access at the target treatment site. While it should be understood that some clots may require retraction of the external catheter along with both the clot and the internal clot retrieval catheter, most clots can likely be removed via the internal clot retrieval catheter. With this combination, the confidence in clearing debris from the lumen of the external catheter is greater, reducing the risk that potential thrombus residue may dislodge from the catheter during contrast agent injection. With conventional catheters, the user typically must remove the external catheter before contrast agent injection to flush out any thrombus residue, at the cost of losing access to the target treatment site. This invention provides a device that minimizes the number of catheter advances required to treat a patient, thereby reducing the likelihood of vascular injury and associated vascular anatomy risks when multiple passes are required.

[0062] Specific examples of the invention will now be described in detail with reference to the accompanying drawings. It should be understood that, when used herein, the end frame, mouth frame, support frame, etc., are interchangeable and all refer to the same structure. The design may typically include a polymer membrane cover, which is usually not shown for clarity of the frame below. While this specification is in the context of mechanical thrombectomy in many cases, the design is also applicable to other procedures and other body access routes.

[0063] Access to various blood vessels within the vasculature to reach clots (whether coronary, pulmonary, or cerebral) involves well-known surgical procedures and the use of many routinely available commercially available accessory products. These products, such as angiographic materials, rotary valves, delivery catheters, and guidewires, are widely used in laboratory and medical procedures. Their function and exact construction are not described in detail when used in conjunction with the disclosure of the present invention as described below.

[0064] See Figure 1 The clot retrieval catheter may have a proximal tubular portion 35 and a distal expandable end 100, which expands radially upon exiting an external or intermediate catheter in which the clot is delivered. The end 100 provides a large distal opening 113 for aspiration, including a clot-catching or thrombus-catching portion 40, the size of which is configured to have an expansion dimension, when unconstrained, nearly the same as or just slightly larger than the expected upper diameter of the target vessel. Figure 2Further illustrated. Therefore, when deployed, the orifice 113 of the distal end 100 may match the diameter of the vessel 20 and have radial force to seal with the vessel, or create sufficient flow restriction such that when aspiration is applied (as indicated by the arrow), blood and the clot distal to the orifice, rather than blood proximal to the distal end, will be drawn into the catheter. If the expanded distal end does not seal or only forms a partial seal, aspiration applied to the clot may be less effective because the flow will be directed proximal to the distal end, reaching the area of ​​the vessel and external catheter 30 that is likely to be less restricted. However, even a partially sealed expandable distal end 100 will still outperform many current aspiration catheters, allowing more cross-sectional area to be opened to the vessel proximal to the distal end. In other examples, an expanded catheter body support tube 35 or a dedicated seal (not shown) may also be used to occupy the lumen between the clot retrieval catheter and the external catheter 30.

[0065] The support tube 35 of the clot retrieval catheter can have many different configurations. The support tube 35 may have one or more axial ridges 42 extending the length of the support tube. For example, Figure 1 The illustrated support tube 35 has two ridges spaced 180 degrees apart. One or more ridges may have a tubular or linear configuration to provide good axial stiffness for catheter advancement and retraction, while also offering excellent lateral flexibility for intravascular navigation. Using multiple ridges facilitates bending along a defined plane while reducing the likelihood of elongation of the support tube 35 under tensile loads, such as when the expandable end 100 is retracted into the orifice of the external catheter. Extending along the length of one or more axial ridges can be a support structure with a series of ribs or a tubular mesh or braid defining the lumen 44 of the support tube 35. The support structure can be a simple circular configuration as shown or, as required, a more complex shape; the example shown has a profile that bends axially when connected to ridge 42. Even when covered by an elastomeric cover or jacket, the substantially cylindrical support tube 35, which does not have a planar cross-section, can have the ability to expand under compression during clot retraction, allowing the tube to "swallow" dense clots that might otherwise be confined to the non-expandable lumen.

[0066] The support tube 35 can be formed from laser-cut thiocyanate tubes or other tubing, or from other similar constructions including a braid with one or more overlapping or interlaced ridges. This allows the support tube 35 to have good push and torque characteristics, a small bending radius, kink resistance, and robust tensile elongation. Commonly used materials include nitinol and common medical-grade stainless steel alloys such as 304 and 316. Different materials of thiocyanate tubes, such as stainless steel for the proximal segment of the tubular support tube and nitinol for the distal portion of the tubular support tube, and for the expansion port, these different materials are connected by welding, bonding, or by holding interlocking features in place with the internal and / or external polymer jacket material.

[0067] The funnel design of the expandable tip 100 in the disclosed example can be a monolithic lattice laser-cut directly and integrally with the support tube 35 of the catheter shaft. Alternatively, the expandable tip mesh can be an injection-molded support or mesh frame constructed as a single piece and attached to the support tube by thermal welding, adhesive, or similar means. The tip can be designed to expand to a wide range of target vessel diameters, such as the distal carotid artery (3.2 mm–5.2 mm), the horizontal M1 segment of the middle cerebral artery (11.6 mm–3.5 mm), and / or the internal carotid artery (ICA, 2.7 mm–7.5 mm). If the catheter subsequently retracts from the M1 segment to the ICA (or has an alternative path with an increasing vessel diameter proximally), the expandable tip 100 can continue to seal with the vessel across a range of vessel sizes. Furthermore, the tip, capable of accommodating various target vessel diameters, can also seal at vessel bifurcations, which may have a wider cross-sectional area than the vessel proximal to the bifurcation and the vessel distal to the bifurcation. Preferably, the expandable tip 100 of the catheter expands at the treatment site to avoid having to push the expanded tip through the vascular system.

[0068] The expandable end 100 is arranged to have one or more ridges connected in series with the ridges 42 of the support tube 35, thereby allowing propulsion force to be transmitted directly to the end via the ridges during propulsion through the external conduit, thus enhancing deliverability. The series connection also allows other circumferential portions of the support tube 35 to remain seamless with adjacent ribs or ends, thereby limiting the impact on the deliverability of the conduit by increasing friction with the external conduit.

[0069] The conduit may also have a cover or membrane (not shown) surrounding or enclosing at least a portion of the support tube 35 and the expandable end 100. Suitable membrane materials may include elastic polyurethane, such as neoprene rubber having a Shore hardness of 40A or lower, or silicone elastomers. A single-stiffness or variable-stiffness cover may be extruded or post-formed over the support tube 35 and the end 100. The cover may also be laminated or thermally welded to the structure.

[0070] Alternatively, the cover may also be formed from a series of polymer jackets. Different jackets or groups of jackets may be arranged at discrete lengths along the axis 111 of the support tube 100 to give different segments of the tubular portion of the conduit different maneuverability and flexibility characteristics. By constructing the jackets axially in series, the overall stiffness of the conduit can transition from a stiffer proximal end to a highly flexible distal end. Alternatively, the polymer jackets of the cover may be a radial series arranged around the support tube to customize material properties throughout the thickness. In another example, the transition between jackets may be tapered or slotted to provide a more seamless transition between the flexible profiles of adjacent jackets in a longitudinal series.

[0071] In such Figures 3A to 3D In the example shown, Figure 1 The expandable tip 100 may have an orifice support frame 110 with a strut having four distal clamps 118 and two support arms 116. The distal clamps 118 may have four proximal clamp grooves 121 and four distal peaks 119. The support arms 116 may conform to the funnel shape of the tip 100, and when expanded and unrestrained, the tip diameter may be in the range of 1 mm to 10 mm, or more specifically in the range of 2.5 mm to 7.0 mm, for devices intended to treat occlusions in the ICA, distal carotid artery, M1, and M2 locations. The support arms 116 may also facilitate having the distal clamps 118 having four proximal clamp grooves 121 fully connected to the support arms, thereby eliminating the risk of the clamp grooves hooking onto the orifice of the external catheter during orifice retraction.

[0072] The support arm 116 may be a V-shaped or Y-shaped strut extending from the support tube 35, which merges at the proximal end 112 of the expandable end 100 with two connectors to the spine 42 or the support tube, and with four connectors to the distal clamp 118. The V-shaped or Y-shaped support arm 116 can provide the frame 110 with support similar to that of a device having four or more support arms, while reducing the number of connections to the support tube 35. Spacing the two connectors to the support tube 110 180 degrees apart allows the support frame 110 to hinge around the connectors when collapsing within the external catheter during advancement through a tortuous blood vessel, or when unfolding in a curved vessel to fully juxtapose the vessel wall with the clamp 118. The hinge action is biased towards a planar bend extending radially through the two connectors of the frame 110 and the longitudinal axis 111. It should be understood that the support frame 110, which has two connectors with the support tube 35, may have an additional support arm extending from a single connector, wherein a distal hoop 118 with more than four proximal grooves 121 is used.

[0073] For situations where distances and curvatures can be significant, such as when the catheter must pass through the heart arch from the patient's inner thigh and ascend into the neurovascular system within the skull, the stiffness and stiffness variations of the oral support frame 110 are crucial. To further customize stiffness, the width of the support arm 116 and the distal clamp 118 can be varied along the length of the support bar by incorporating one or more stenotic segments 124. For example, a larger width at the peak of the V-shaped support arm 116 provides greater radial force capacity, while a narrower intermediate segment helps reduce lateral stiffness to facilitate bending and traversing the tortuous vascular system. A larger width of the proximal groove 121 adjacent to the distal clamp 118 also provides increased radial force. The stenotic segment 124 at the distal clamp peak 119 softens the distal end of the expandable tip 100 to improve the non-invasive characteristics of the tip, and the stenotic segment 124 also helps the clamp 118 collapse back into the orifice of the external catheter by reducing the force required to collapse the distal peak 119 of the frame 110.

[0074] Go to Figures 4A to 4D The support frame 110 may have an array of four Y-shaped support arms 116, each Y-shaped support arm having two support struts, and four distal hoops 118 having four hoop grooves 121 and four distal hoop peaks 119. The arrangement of two support struts per support arm 116 allows for greater support of the cover or outer sleeve, while limiting the number of distal peaks 119 to four, thus allowing the distal hoops 118 to have a larger, more rounded, non-invasive profile. Figure 4A As shown, four connectors are provided between the proximal end of the oral frame 112 with four support arms 116 and the support tube 35, allowing the connector to have greater axial stiffness at the end with only two connectors if the end 100 needs to be advanced in an expanded configuration. The curvature of the support arms 116 also allows the frame 110 to extend and shorten on opposite sides when it collapses in the external catheter, enhancing trackability through tortuous vessels.

[0075] Another support frame 110 may have six Y-shaped support arms 116 and six hoops 118 with six distal peaks 119, as shown. Figures 5A to 5D As shown. It should be understood that the number of distal peaks 119 and support arms 116 employed can vary from 1 to 50 or more. Configurations that increase the number of distal peaks 119, hoops 118, and / or support arms 116 can provide increased support, increased lateral frame stiffness, and radial forces for the outer cover or jacket. Similar to other examples, segments of frame 110 may have struts of variable width to customize desired flexibility characteristics and offset bending at certain points on the frame.

[0076] Figures 6A to 6DAnother example of a support frame 110 for an expandable end 100 is shown, which may have six clamps 118, six distal peaks 119, and six support arms. Two of the support arms may be Y-shaped support arms 152, which connect to the support tube 35 at the proximal end 112 of the frame 110, while the other four arms may be V-shaped support arms 154, which terminate at the peak 117 proximal to their respective clamp support grooves 121. This design provides the frame 110 with closed-cell support clamps 118 to enhance the radial force capacity of the end 100, while having only two connections to the support tube 35. Spacing the two connections of the support tube 35 180 degrees apart allows the frame to hinge around the support in a plane extending radially through the Y-shaped support 152 and the longitudinal axis 111. When deployed in a tortuous vessel, this hinge allows for enhanced trackability through external catheters and improved conformability to the vessel wall.

[0077] The V-shaped support arm 154 provides additional surface area to support the outer covering or membrane (not shown). The outer membrane reduces the likelihood that the proximal peak 117 of the V-shaped arm 154 will snag on the orifice of a branch vessel or external catheter during retraction. In another example, the proximal peak 117 of the arm 154 may be more rounded or U-shaped, similar to the distal peak 119 of the support clamp 118.

[0078] In another example, the orifice support frame 110 for the clot retrieval catheter may have six distal hoop peaks 119, two Y-shaped support arms 152, and four V-shaped support arms 154, as shown. Figures 7A to 7D As shown. The V-shaped support arm 154 may have an eyelet 127 at its proximal peak 117 that is longitudinally aligned with the eyelet of the support tube 35. An array of connecting members 128 may extend between the eyelets 127 and be connected to the respective eyelets by knotting, welding, or plastic deformation to form spheres, rings, or enlarged abutments. Alternatively, the polymer components may be formed into a bulb using a thermoforming process. The connecting members 128 may be linear members, chain-like connecting members, rigid or semi-rigid members, or combinations thereof. Alternatively or in addition, radiopaque markers (not shown) may be provided in the eyelets 127 to aid in the positioning of the opening 110.

[0079] Similar to other examples, this design provides a closed-hole structure for the distal clamp 118 to provide enhanced radial force, while the eyelet 127 and connecting member 128 mean that there are only two rigid connections at the proximal end 112 to the Y-arm 152 of the support tube. Spacing the connections between the support tube 35 and the Y-arm 152 at diameter-opposite locations allows the frame 110 to hinge around the connections via an external catheter for trackability and better conformability when the target location is within a tortuous blood vessel.

[0080] The array of connecting members 128 reduces the likelihood that the free proximal peak 117 of the V-shaped support arm 154 will hook onto the orifice of the external catheter when the expandable tip 100 retracts. The connections between the connecting members and the eyelets 127 at the proximal peak 117 of the V-shaped arm 154 and the eyelets of the support tube are not rigid, allowing the members to move loosely through the eyelets 127 of these connections, enabling the support frame 110 to bend easily in tortuous blood vessels. If the connecting members 128 were made flexible, they would not contribute to the bending stiffness of the tip 100 in a collapsed state, but they could become taut once the distal support clamp 118 expands. The flexible members can be strong enough to support the external cover or membrane, thereby counteracting the negative pressure applied to the cover during aspiration.

[0081] Another example of a mouth frame 110 may have a distal support hoop 118 having six peaks 119 surrounding the periphery of the mouth, as shown below. Figures 8A to 8D As shown. Frame 110 may have three Y-shaped support arms 152 connecting adjacent hoop grooves 121 to support tubes 35. While similar in some respects to the previously described example, the expandable end 100 with three support arms will be more flexible in the collapse delivery configuration than an end with more arms. Fewer connections to the support tubes also help frame 110 collapse back to the constrained state upon retraction.

[0082] Figures 9A to 9D Another support frame 110 is shown with four distal clamps 118, each clamp having four circular distal peaks 119 and four clamp grooves 121. The struts of the distal clamps 118 may be tangentially aligned with four support arms 116 extending from their respective clamp grooves 121 to the support tube 35. The support arms may have a circumferential undulation or sinusoidal waveform pattern 130 along at least a portion of their length, wherein together with the support arms, they define a substantially conical profile of the support frame 110. The sinusoidal pattern 130 may be arranged such that, when the end 100 is in a collapsed configuration, the local peaks of adjacent support arms 116 do not overlap, but rather can be nested together to fold the frame in a complementary manner. The amplitude of the waveform pattern 130 may be selected to be large enough to provide adequate support to the polymer overlay or outer jacket, without being so large that the support arms 116 need to be longitudinally extended to collapse neatly within the external conduit. The waveform pattern 130 gives the frame 110 flexibility so that it can shorten and lengthen in all directions when the end is followed by an external catheter in a tortuous blood vessel, or when it is deployed in a complex geometry at a target location, it can conform to the vessel wall and achieve complete juxtaposition with the vessel wall.

[0083] To optimize lateral flexibility, the support frame 110 can be configured such that, when the frame is in a flat pattern or planar view, the struts of the wave pattern 130 forming the support arm 116 form an angle between 45 degrees and 135 degrees relative to the central longitudinal axis 111. In this configuration, when the frame is subjected to torsional moments, the more longitudinally oriented portion of the support arm 116 can be biased and bent around the struts extending between the peaks of the wave pattern 130, making the support arm more dependent on torsional flexibility than lateral flexibility. It should be understood that if some torsional flexibility needs to be traded off for additional lateral bending flexibility, the angle formed by the struts of the pattern can fall outside the 45-135 degree range.

[0084] exist Figures 10A to 10D In a similar example shown: the support frame 110 may have a distal hoop 118 with four circular distal peaks 119 and four support arms 116 with a sinusoidal waveform pattern 130 extending from the hoop groove 121. Figure 9A Compared to the example in the previous example, support arm 116 may have additional local peaks in the wave pattern 130, allowing the frame to have a smaller effective gap between adjacent support arms and providing additional support for the flexible outer membrane or cover. The additional undulations in the pattern also create a larger strut length along which torsional and lateral strains can be distributed when the frame 110 is bent and tracked through the external conduit.

[0085] Similar to Figures 10A to 10D Another support frame 110 of the expandable end 100 is shown. Figures 11A to 11D The frame may have four distal hoops 118 and four support arms 116, each support arm having a sinusoidal wave pattern 130 along at least a portion of its length. As described, the number of peaks and the amplitude of the undulations in the wave pattern 130 can be tuned for desired flexibility characteristics of the frame 110. Furthermore, the width of the struts can be adjusted to maintain flexibility while achieving the desired radial force.

[0086] Frame 110 may have one or more additional struts acting as one or more torsion members 132, extending between proximal clamping grooves 121 of support clamp 118. The torsion members 132 may extend in a circular manner about the central longitudinal axis 111 of the device, as shown, such that they can move distally under torsional loads during retraction into the external catheter. This movement can help frame 110 clamp rigid clots that would otherwise be completely confined into the catheter lumen 44, such that the clamping of the clots is fixed when the catheter is withdrawn through the vascular system. In another example, the circumferential peak 119 and / or a portion of the torsion member 132 may have an axially circular or curved profile, or the struts may intersect at a midpoint to act as hinges and reduce the transmission of torsional moment when frame 110 collapses. This reduced moment may be advantageous in devices where the outer cover or jacket is constructed of a harder material with reduced elastic strain capacity and elongation at break, as it will not be necessary to move the cover as much as the frame folds or collapses into the external catheter.

[0087] Another example of a support frame 110 having a distal hoop 118, four support arms 116 and four hoop peaks 119 is disclosed. Figures 12A to 12D Each support arm 116 may branch between the annular groove 121 and a more proximal support groove 126 to form an enlarged unit or opening 220. The enlarged opening in the arm 116 allows the arm to shorten and lengthen on opposite sides of the longitudinal axis 111 of the frame, enabling easy tracking of external catheters through tortuous vascular pathways. The branching of the support arm 116 allows the arm to twist and bend more freely than if a single support bar directly connects the annular groove 121 to a support groove 126 without a unit. The connector at the clamp groove 121 may also be axially longer than... Figure 12C The joints shown are designed to better distribute lateral and torsional strain when the frame 110 needs to flex between the annular peaks 119. Similarly, the enlarged openings may also have smaller or larger spacing than shown to further facilitate independent movement of the support arms 116 relative to each other.

[0088] The struts of the distal clamp 118 may also have a different width than the struts of the support arm 116. For example, a wider or thicker strut near the clamp peak 119 can provide greater radial force capacity for the support frame 110 at the clamp and the more flexible support arm. A narrower strut near the peak 119 can allow the clamp to be more compliant when sealing with the vessel wall.

[0089] Another support frame 110, with four branch support arms 116 and four ring apex 119, is as follows: Figures 13A to 13D As shown. With Figures 12A to 12DCompared to the previous design, this design may be characterized by a modified shape of the hoop groove 121 connecting joint, wherein the direct connection allows for a smoother transfer of load between the segment of the distal hoop 118 and the enlarged unit 220 of the support arm 116. The shape of the hoop groove 121 may also be altered to adjust the intersection angle of the sub-support bars forming the distal hoop 118 and the support arm 116, thereby customizing the axial stiffness of the support frame 110.

[0090] Figures 14A to 14D Another configuration of the oral support frame 110 with four support arms 116 is shown, these arms having enlarged unit openings 220 and both a proximal support ring 134 and a distal support ring 118. The distal support ring 118 may have four ring peaks 119 and engage proximally at four corresponding ring grooves 121. An array of connecting struts 136 connects the more distal ring groove 121 to the proximal ring groove 123, which serves as a joint between the strut of the proximal support ring 134 and the support arm 116. The device with multiple support rings in axial tandem can apply greater radial force to improve juxtaposition and sealing with the target vessel. The seal provided by the expandable end 100 allows for more efficient aspiration by directing full aspiration power to the vascular portion distal to the end, while maintaining the funnel-shaped profile to provide a converging inlet for the gradually elongating clot and prevent clot shearing and fragmentation.

[0091] Various views of the design of the expandable support frame 110 having an elongated connecting strut 136 between the distal hoop 118 and the support arm 116 are shown in the figure. Figures 15A to 15D The connecting strut 136 extends between the end of the support arm 116 of the enlarged unit opening 220 and the strut of the distal clamp 118. When manipulated in an external catheter, the enlarged opening 220 in the arm 116 allows the end 100 to shorten and lengthen on opposite sides, while allowing the connector 136 to have a greater length to provide greater lateral flexibility during bending, thus allowing the distal support clamp 118 to bend and flex relative to the support arm in a tortuous path. Additionally, the length of the connecting strut 136 can be varied, or even include bends or undulations, to allow for different profiles of the cover or external clip to provide a more atraumatic interface with the vessel wall.

[0092] Figures 16A to 16DAnother variation of the support frame 110 is shown, featuring a distal support clamp 118 and four support arms 116 with enlarged openings for flexibility. The struts of the support arms 116 may have a first strut width 114 along at least a portion of the length between the support groove 126 and the clamp groove 121, which differs from the second strut width 146 used in the support clamp 118. For example, the second strut width 146 of the clamp may be thinner, thereby reducing the radial force generated by the clamp and providing a gentler contact with the vessel wall. A thinner clamp also reduces friction between the clamp 118 and the inner diameter of the external catheter, allowing the tip to be more easily advanced and retracted through the external catheter. Similarly, the increased thickness of the first strut width 114 in the support arm 116 can counteract the reduced radial force of the support clamp 118 by providing increased stiffness during distal expansion of the tip 100, resisting negative pressure generated during aspiration, thereby keeping the frame 110 expanded and juxtaposed with the vessel wall. Arm 116 may also have closed or undulating sections to provide more surface area to support the outer cover or membrane.

[0093] Depending on the location of the occluded blockage and the necessary pushability and flexibility requirements of the support frame, other advantages can be obtained by changing the strut width of the frame's support arms. The support frame 110, with four support arms 116, has an enlarged occluded opening and struts of variable thickness, such as... Figures 17A to 17D As shown. The support arm strut may include one or more narrowing sections 124 along its length between the proximal support groove 126 and the distal clamp groove 121. When the frame 110 is in a constricted configuration for advancement through an external catheter, or when the frame is deployed within a tortuous vessel, the narrowing sections 124 enhance the lateral flexibility of the frame, allowing it to twist while maintaining complete juxtaposition with the vessel wall. If the narrowing sections 124 are located in the middle span of the support arm strut 116 and away from the support 126 and clamp groove 121, the frame can maintain high flexibility and support for the membrane.

[0094] When flexible properties are added to the support arm 116 of the end frame 110, the radial force capability of the end 100 can be maintained by a more relaxed support arm angle α relative to the longitudinal axis 111. Adjustable radial force allows for maintaining a sufficient seal without causing vascular trauma. For example, when the end frame 110 is heat-set at an angle α equal to or greater than 30 degrees, a larger component of the stretching force can be applied in the radial direction.

[0095] Various views of an expanded support frame 110 with a smaller conical funnel shape and four support arms 116 with reduced support arm angles θ are shown. Figures 18A to 18D In the middle. The support arm angle θ can be, for example, approximately 30 degrees, rather than as... Figures 17A to 17DThe angle is approximately 45 degrees, as shown. A smaller support arm angle reduces the force required to advance the device through the external catheter, while also reducing the stress required to retract the expansion frame 110 into the external catheter during surgery. These forces can be further reduced by incorporating a widened or narrowed section 124 into the arm 116 and / or the distal clamp 118.

[0096] Alternatively, the support arm angle θ can be within the following range: less than 45 degrees so that the catheter tip 100 is unlikely to expand further when advanced distally in the external sheath or blood vessel, but greater than 10 degrees so that the length of the catheter orifice frame 110 remains relatively short. Optimizing the support arm angle θ can also help with the placement of the tip 100 against the distal end of the external catheter and the wall of the target blood vessel.

[0097] When in an expanded state, at least a portion of the ostial frame 110 may taper distally from a larger peak radial dimension to a smaller radial dimension. In this configuration, the external axial profile of the distal body may also be generally circular to provide a smooth interface with the vessel wall. A portion of the distal support hoop 118 may extend radially inward, such as... Figure 18D As shown, this reduces the likelihood of the distal hoop 119 being pressed into the vessel wall and allows the dilated end to advance a shorter distance through the vessel without causing vascular damage.

[0098] Figures 19A to 19C Another support frame 110 is shown, consisting of four support arms 116 connected to the expandable end 100 of the support tube 35. This frame 110 may also have a smaller support arm angle θ than previously seen designs. A portion of the distal support clamp 118 may extend radially inward between adjacent clamp grooves 121. The support arms 116 may be clockwise spaced at 90-degree intervals around the longitudinal axis 111 and may branch to form one or more closed openings, allowing the frame to elongate and shorten on opposite sides while navigating through the tortuous regions of the vascular system. Additionally, the support arms 116 may include one or more wave patterns or undulations 130 between the proximal end 112 and the distal end 114, including portions of closed openings or sections adjacent to the more proximal support groove 126 and the more distal clamp groove 121, as shown. The undulations 130, combined with the narrowing section 124, enhance the lateral flexibility of the support frame.

[0099] Support arm 116 may be connected to the support tube 35 of the catheter at the proximal end 112 of the oral frame 110. One or more ridges 42 of the support tube may be aligned with one or more support arms to allow for smooth transmission of longitudinal forces between the ridge and the frame. Support arms 116 not aligned with ridges 42 may be connected to support arms that are aligned or terminated at a point near the distal end of the support tube 35. In this configuration, the compressive forces generated during clot retrieval may not cause undesirable expansion of the support tube 35 or the oral frame 110 during the procedure.

[0100] Any of the mouth support frames 110 disclosed herein may be encapsulated or sealed by an elastomeric membrane cover 50. Although the cover is not shown in many of the foregoing figures for clarity, Figure 20 It is shown how the membrane 50 may cover at least a portion or all of the struts of the mouth frame 110 of the expandable end 100 and at least a portion of the circumferential ribs 43 and axial ridges 42 of the support tube 35.

[0101] The thickness of the membrane cover 50 may be maintained between and above the struts of the mouth support frame 110, or its thickness may vary along the frame 110. In one example, the cover 50 may be applied with the thickness of the membrane between the struts close to the ligament thickness of the membrane above and below the struts. In another example, the cover may have a uniform wall thickness, wherein the thickness between the struts is greater than the remaining ligament thickness above and below the struts. The membrane cover 50 may also include geometric features and / or thinning regions that are appropriately positioned to alter the stiffness contribution from the membrane to the overall assembly of the support frame 110 and the cover together.

[0102] The membrane cover 50 can be sewn to the support tube 35 and the mouth frame 110 struts, or it can be reflowed above and between the struts (to be flush with the inner surface of the support struts, or an inner and outer layer can be used such that the struts have membrane material above the outer surface and below the inner surface of the support struts), heat-shrink and bonded to the outer surface of the support struts, or welded to the appropriate position in the defined area 52. The cover 50 can also be formed by an impregnation process (to be flush with the inner surface of the support struts, or an inner and outer layer can be used such that the struts have membrane material above the outer surface and below the inner surface of the support struts). The manner in which the cover 50 is adapted to the distal end 114 of the mouth frame 110 can also be varied, such as... Figures 21A to 21C The outline example is shown. The membrane cover 50 may be coated with a planar (…). Figure 21A Alternatively, the cover may be trimmed to conform to the profile of the support frame 110 struts and heat-welded along the periphery of the distal hoop 118 in zone 52. Figure 21B Heat can be locally reflowed and / or bonded to the support struts, and bonding can be achieved at least in the region of the hoop peak 119 of the distal hoop 118. Figure 21C In another example, the cover 50 may be loosely or drooping enough to fold radially inward (or radially outward) to a position proximal to the distal end 114 of the mouth frame brace 118, and be thermally welded or otherwise bonded between the inner and outer layers. The membrane may extend fully within the frame so that the frame brace is not exposed.

[0103] The membrane cover 50 may have a configuration in which it has good ductility and a high elastic strain limit, allowing it to expand easily by a minimum radial force from the underlying support frame 110, such as... Figure 22 As shown. Alternatively, if the cover 50 is formed in an expanded configuration of the frame with an elastomer or non-compliant material, it is able to neatly wrap when collapsed for delivery and recover when expanded for use. The membrane cover 50 may be formed with a circular opening and may include soft elastomer or gel ribs 54 (formed by reflow, impregnation, or molding processes) to provide non-invasive contact with the vessel wall, as shown. The cover of the opening support frame 110 may also have flow guiding features, such as multiple flexible fins, blades, or grooves arranged around the outer and / or inner circumference in a configuration that incorporates vortices or laminar flow. Such structures may be included in a molded or shaped mandrel.

[0104] To allow for smooth delivery of the clot recovery catheter through the external conduit and smooth delivery of the auxiliary device through the lumen of the clot recovery catheter, the outer surfaces of the expandable tip and / or membrane or outer jacket may be coated with a low-friction or lubricating hydrophilic material, or a low-friction material (such as a fluoropolymer, like PTFE or FEP). Additionally, the inner surfaces of the expandable tip struts or the inner surfaces of the membrane cover (if it encapsulates the tip) may also be coated with a liner or otherwise manufactured to have low-friction properties.

[0105] In many examples, the support tube 35 may also share an external and / or internal lubricating film or coating with the end 100. The coating may be delivered via impregnation, spraying, plasma, shaped mandrel, or any other commonly used technique. Alternatively, the film cover or jacket may be impregnated with particles having low-friction properties.

[0106] In another example, the ostial frame 110 may include an electrospun or other porous covering that allows for reduced blood flow proximal to the distal vessel wall seal. A flow reduction between 50% and 99%, more preferably 60% and 80%, will still direct most of the aspiration flow to the clot while allowing a small portion of recovery flow proximal. This flow can help reduce the likelihood of vessel collapse under excessive aspiration in locations where the vessel has little support from surrounding tissue, or where there are no branches between the obstructed vessel and the dilated distal end 100 and where a mechanical thrombectomy device or stent thrombectomy device cannot open a portion of the obstructed vessel.

[0107] Other mouth support frame examples may have longitudinal supports that are independent of each other on the distal side, allowing them to flex individually. Figures 23A to 23DOne configuration is shown where the expandable end 200 has a support frame 210 with a plurality of interconnected struts formed to arrange unconnected flaps 215 around the longitudinal axis 111 of the device. The flaps 215 may have distal clamping members 218 engaging one or more longitudinal arms 216, and the size and shape of the flaps may be configured such that there is no overlap between them. Alternatively, the flaps 215 may be oversized, allowing them to overlap each other while being held in the desired expanded shape by the membrane covering. Overlapping flaps can help increase the radial force capacity of the frame while sliding relative to each other to share and distribute strain during surgery.

[0108] Similar to other disclosed examples, and without constraint, the flap 215 is radially expandable such that the combination of arms 216 around the longitudinal axis 111 forms a substantially tapered surface. The struts of the longitudinal arms 216 may branch to form one or more undulations or obturators 220, thereby allowing the flap 215 to independently lengthen and shorten in response to forces experienced during navigation through an external catheter or during thrombectomy when the distal end 200 is deployed and expanded at the target site. Close alignment of the longitudinal arms 216 with the longitudinal axis 111 of the distal end 200 maintains good column stiffness and pushability. The flap 215 may also include additional components to enhance the radial forces of deployment and further support the membrane covering during aspiration.

[0109] The support frame 210 may also have a proximal support hoop 230 extending distally from the support groove 126, which forms a connector with the support tube of the conduit (not shown for clarity). The connecting strut 236 may form the distal terminating peak of the proximal support hoop 230 and may connect the hoop to the longitudinal arm 216 of the frame.

[0110] Figures 24A to 24D Various views of an alternative support frame 210 with a conduit, having a distally unconnected flap 215. The struts of the proximal support clamp 230, longitudinal arm 216, and distal clamp member 218 may have variable or tapering thicknesses between the proximal end 112 and distal end 114 of the support frame 210. The strut of the support clamp 230 may, for example, be thicker than the strut of the connecting strut 236, which in turn may have a greater thickness than the strut of the longitudinal arm 216 forming the orifice 220. Similar to the locally narrowed sections in other examples, this gradual thinning distally of the strut width of the orifice frame 210 maintains radial force capacity while preserving the flexibility of the individual flaps 215, allowing them to respond independently to lateral loads.

[0111] In similar variations, Figures 25A to 25D Different orientations of the support frame 210 for the expandable end 200 are shown, the expandable end having eight proximal support hoops 230 connecting four distal unconnected lobes 215. Figure 25BIn the process, the support groove 126 forming the proximal end of the support hoop may have staggered axial spacing, and the intersection points of the support bars at the proximal and distal sides of the connector 236 and the closed hole 220 may be aligned with... Figure 24C The different angles appear to allow for more equal and balanced strut spacing throughout the frame 210.

[0112] Alternatively, the mouth support frame 210 with the distal unconnected flap 215 may have a direct connection to the support tube, a common axial strut, or a direct connection to the distal rib or lip (not shown). A support frame with a direct connection is shown in... Figures 26A to 26D In this design, the catheter has eight longitudinal arms 216 that engage four distal clamp members 216 to form four unconnected flaps 215. In this example, the direct connectors of the longitudinal arms 216 at the proximal ends 112 of the frame 210 can replace or supplement the proximal support clamps 230 formed by other designs. The direct connectors allow the individual flaps to flex and bend more freely around the support frame and relative to each other when the catheter encounters a tortuous advancement path.

[0113] The longitudinal arm 216 may include one or more occluders 220 to maintain the necessary radial force while providing additional support for the membrane cover. The spacing between the direct proximal connector and the occluders allows the lobes to overlap or not overlap each other while the covered portion is maintained in the desired radial shape of the frame, and to collapse neatly at the ends when folded into the external conduit.

[0114] Figures 27A to 27D An alternative expandable end 200 is shown, wherein the ostial frame 210 has six distally unconnected flaps 215 and six longitudinal arms 216, each longitudinal arm extending from a direct connector at the proximal end 112 to a support tube (not shown). Each longitudinal arm 216 may each include one or more obturators 220 terminating at the distal end 114 in a generally circular clamp member 218. A portion of the clamp member 218 of the flaps 215 may be radially inwardly bent to present a diameter slightly smaller than the peak maximum expansion diameter of the end 200 profile. This bending reduces the likelihood of the distal clamp member 218 being pressed into the vessel wall and allows for brief advancement of the expandable end through the vessel if necessary, without causing vascular damage.

[0115] The support frame 210 may also have six longitudinal arms 216, each extending from a direct connector at the proximal end 112 to form six distal unconnected lobes 215, such as Figures 28A to 28DAs shown. When unconstrained, the lobe 215 expands radially, such that the profile of the assembly of arms 216 around the longitudinal axis 111 can be substantially tapered. One or more of the longitudinal arms 216 may have circumferential undulations 130 or a wave shape along at least a portion of their profile. The undulations 130 give the arm profile a greater support area for the membrane cover while enhancing the lateral flexibility of the frame 210. The support area of ​​the cover can be further enhanced by increasing the amplitude of the undulations, reducing their oscillation period, or both. The undulations 130 may also be staggered or otherwise configured to nest together and fold in a complementary manner when the frame is in a collapsed configuration. Additionally, the longitudinal arms 216 may be sealed at their distal ends by clamping members 218 to form a ring or closed aperture 220. The distal ends of the closed apertures 220 of the arms 216 may taper inward from the maximum expansion diameter of the frame, as... Figure 28B and Figure 28D As shown, this is to give frame 210 a more non-invasive profile.

[0116] As from Figures 29A to 29C Observedly, the alternative expandable mouth support frame 210 may have five unconnected lobes 215 equidistantly spaced around a longitudinal axis 111. A longitudinal arm 216 constituting each lobe may be independently connected to the support tube. The struts of the longitudinal arm 216 have a first thickness near the proximal end 112 and a second thickness in a more distal region of the arm to combine good pushability with distal flexibility. Similar to other examples, the arm 216 may have undulations 130 to allow the arm to bend and flex independently about its own axis, and may have distal closures 220 to provide greater support for the membrane cover.

[0117] It should be understood that, compared to six or more designs in other examples, Figures 29A to 29C The fewer unconnected flaps 215 in the membrane allow for a non-traumatic curve at the distal end and increased flexibility for a given strut thickness and width. To maintain adequate support for the membrane cover, the design with fewer flaps can be combined with additional undulations 130 and / or obturators 220, sufficient to provide adequate radial force and prevent the cover from collapsing under suction during surgery.

[0118] Several views of a support frame 210 having multiple undulations or waveforms 130 along the length of the longitudinal arm 216 and having an array of closed holes 220 around the longitudinal axis 111 at the distal end 114 are shown in 30A to 30A. Figure 30DThe undulation 130 can be circumferential and have a smooth, periodic oscillation, or the arm and oscillation can be twisted in a helical direction relative to the axis 111. The additional length of the undulation in the arm 216 allows each valve 215 to twist and bend more independently of the other valves around the longitudinal axis of the arm, providing a device that will be easier to track through an external catheter when the frame is in a collapsed state. The helical twist in the arm 216 can also help the valve 215 torsion through tortuous vascular anatomy.

[0119] In another alternative configuration, the expandable orifice 300 of the catheter may have a radial array of struts or strands organized into a closed-pore grid 310, such as Figures 31A to 31B As shown. The mesh may have a proximal end 112, a distal end 114, and, when unconstrained, form a substantially conical or funnel-shaped shape around a longitudinal axis 111, allowing expansion upon exiting the external conduit. The mesh array may be made of wire or cut from a shape memory alloy, such that the opening can be heat-shaped to expand from a collapsed delivery configuration to an enlarged deployment configuration. The mesh 310 may be adhered to or otherwise attached to the support tube 35 of the conduit at the proximal end 112. The mesh pattern 310 may be manufactured to have a single circumferential joint for attaching the proximal end, or, when the support tube 35 has a structure of ribs 43 and ridges 42, individual strands of the mesh may be bonded to the distal rib of the tube. Flexible polymer membrane 50 (such as...) Figure 22 (As shown) may cover some or all of the closed-pore grid 310 of the catheter tip 300.

[0120] In another example, the support tube 35 may have a configuration of metal and / or polymer strands formed as a patterned grid or coiled structure. This structure can be formed as a radial array of continuous tubular conduit bodies, and in some cases, even integral with the expandable end 300. In this case, the stiffness transition between the support tube 35 and the end 300 is minimized to approximate a single support and better distribute strain. The tube may be coated or encapsulated with a cover or membrane to provide a smooth surface for traceability within the internal channels of external conduits and auxiliary devices.

[0121] Figure 31B A closer view is shown of a possible repeating pattern of the closed-cell mesh 310 exhibiting expandable ends 300. When cut from a flat pattern, the radial profile of the resulting mesh pattern 310 can be straight, as shown, having a constant angle relative to the longitudinal axis 111. In other examples, the profile can be a wider, open concave arc to form a more non-invasive and rounded outer surface for contact with the vessel wall.

[0122] The closed-cell mesh array 310 constituting the mouth frame can be a continuous polygonal pattern as shown, such as triangular or quadrilateral cells that interlock by sharing the vertices of adjacent cells. In one case, the array 310 may have, for example, Figure 31B The elongated quadrilateral pattern shown forms individual occluders at shared vertices marked by local array peaks 312. This pattern can be repeated axially and radially, and the distal array peaks 312 of adjacent units can be joined by curved distal clamps 314 or coronal portions to mark the periphery of the dilatable ostium. Similarly, the peaks of the distal clamps can be joined together by a single circumferential clamp or coronal portion to prevent the individual distal clamps from getting stuck or hooked onto branch vessels or similar features.

[0123] The cells formed by the shared array peaks 312 define the openings 316 of the closed-pore mesh 310 structure. The size of the openings 316 of the mesh can be set to customize the filtration characteristics of the expandable end 300. For example, larger openings can impart enhanced flexibility to the end, resulting in delivery advantages, while in conjunction with an external membrane cover or jacket (not shown) to block or restrict blood flow from the proximal region of the end when deployed in an expanded configuration at the target site.

[0124] Alternatively, the holes 316 can be micro-sized to form a mesh array 310, which is dense enough to adequately prevent flow to locations where an external jacket or membrane cover is not required. In this case, the outer cover of the support tube 35 may terminate near or in the region of the distal region of the proximal end 112 of the expandable end 300, where the diameter of the end begins to expand in the deployment configuration. Since no external membrane cover is required, the expandable end 300 can be more easily tracked through the external conduit, and the required propulsion force can be limited. Therefore, although a lubricating or low-friction coating can still be applied, it may not be necessary.

[0125] A variety of minimally invasive stent patterns, grids, or screens exist among commercially available products with a range of capabilities and applications. It should be understood that the closed-pore grid 310 of the expandable end 300 can utilize any expandable stent pattern known in stent patents and the product field, and the aperture 316 size need not be limited to those disclosed herein.

[0126] The invention is not necessarily limited to the described examples, the configurations and details of which may vary. The terms “distal” and “proximal” are used throughout the foregoing description and refer to position and orientation relative to the treating physician. Similarly, “distal” or “towards distal” refers to a position away from the physician or in a direction away from the physician. Likewise, “proximal” or “towards proximal” refers to a position close to the physician or in a direction toward the physician. Furthermore, unless the context clearly indicates otherwise, the singular forms “an,” “a,” and “the / described” include plural references.

[0127] As used herein, the term “about” or “approximately” for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of values ​​±20% of the listed values; for example, “about 90%” may refer to a range of values ​​from 71% to 99%.

[0128] In describing the example embodiments, terminology is used for clarity. Without departing from the scope and spirit of the invention, each term is intended to be contemplated for its broadest meaning as understood by one skilled in the art, and includes all technical equivalents that operate in a similar manner to achieve a similar purpose. Similarly, it should be understood that reference to one or more components in an apparatus or system does not exclude the presence of additional components or intermediate components between those explicitly identified components. Reference to one or more steps of a method does not exclude the presence of additional method steps or intermediate method steps between those explicitly identified steps. For clarity and brevity, not all possible combinations are listed, and such modifications are generally apparent to one skilled in the art and are intended to fall within the scope of the appended claims.

Claims

1. An expandable port for a clot retrieval catheter, the expandable port comprising: Proximal end; distal end; Longitudinal axis; and A self-expanding mouth frame, comprising a plurality of interconnected struts, a collapse delivery configuration, an expansion deployment configuration, and a polymer membrane cover, wherein the struts of the mouth frame include: One or more support arms, extending longitudinally between the proximal end and the distal end, and forming a substantially tapered surface about the longitudinal axis in the deployment configuration, and One or more distal clamps, the one or more distal clamps forming the circumferential periphery of the orifice opening of the clot retrieval catheter. The expandable mouth also includes a support tube connected proximally to the mouth frame, the support tube comprising multiple ribs and one or more axial ridges. The mouth frame and the support tube have only two hinged connections.

2. The expandable mouth according to claim 1, wherein the mouth frame further includes one or more narrowing sections.

3. The expandable opening according to claim 1, wherein at least one axial ridge of the support tube is axially aligned with the support arm.

4. The expandable mouth according to claim 1, wherein in the deployed state, the mouth frame is tapered such that the proximal portion of the mouth frame has a first radial dimension, and the distal portion of the mouth frame has a second radial dimension greater than the maximum dimension of the first radial dimension.

5. The expandable opening according to claim 4, wherein the maximum dimension of the second radial dimension is at least 2.5 mm in diameter and the dimension is set to be larger than the inner diameter of the target blood vessel.

6. The expandable mouth according to claim 1, wherein at least a portion of the one or more distal hoops extends radially inward from the maximum dimension in the radial direction of the mouth frame.

7. The expandable opening according to claim 1, wherein the width of at least a portion of the strut of the support arm is different from the width of at least a portion of the strut of the distal hoop.

8. The expandable opening according to claim 1, wherein the strut of at least one of the one or more support arms terminates at a support groove and a hoop groove to form a closed opening.

9. The expandable opening according to claim 1, wherein the one or more support arms include at least one circumferential undulation.

10. The expandable opening according to claim 1, wherein the strut of at least one of the one or more support arms terminates at the support tube and the hoop groove to form a closed opening.

11. The expandable opening according to claim 1, further comprising: The angle formed between the support arm and the longitudinal axis has a range of 10 degrees to 45 degrees.

12. The expandable opening according to claim 1, further comprising: The angle formed between the support arm and the longitudinal axis is approximately 30 degrees.

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