Clot retrieval device for removing clot from blood vessel

Abstract

To provide a clot retrieval device for removing a clot from a blood vessel.SOLUTION: The device can include a collapsed configuration and an expanded configuration. The device can include an inner expandable body with a framework of struts. The device can include an outer expandable body with a framework of struts that at least partially radially surround the inner expandable body. A distal portion of the outer expandable body extends in the deployed configuration towards the outer expandable body to a greater extent than the inner expandable body, where closed cells of the distal portion distally taper and are smaller than cells proximal thereto in the outer expandable body. The plurality of closed cells of the distal portion can include a pair of axially aligned smaller diamond shaped cells formed by struts of the distal portion and positioned along upper and lower regions of the distal portion.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates generally to devices and methods for removing blockages from blood vessels during intravascular medical procedures. [Background technology]

[0002] Clot retrieval devices are used for mechanical clot removal for endovascular interventions, especially when patients suffer from acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE), etc. Acute obstructions can include clots, misplaced devices, dislodged devices, large emboli, etc. Thromboembolism occurs when part or all of a clot detaches from the vessel wall. This clot (referred to herein as an embolus) is then carried in the direction of blood flow. Ischemic stroke can result when a clot lodges in the vasculature of the brain. Pulmonary embolism can result when a clot develops in the venous system or on the right side of the heart and lodges in the pulmonary artery or its branches. Clots can also develop in the form of emboli without being released to locally block a blood vessel, a mechanism that is common in the formation of coronary artery blockages. There are significant challenges associated with designing clot removal devices that can provide a high level of performance. First, there are many access challenges that make it difficult to deliver the device. When access involves navigating the aortic arch (such as in a coronary or cerebral occlusion), the shape of the aortic arch in some patients makes it difficult to position the guide catheter. These difficult aortic arch configurations are classified as Type II or Type III aortic arches, with Type III aortic arches presenting the greatest obstacle.

[0003] The tortuosity problem is even more severe in arteries approaching the brain. For example, it is not uncommon at the distal end of the internal carotid artery for the device to have to navigate several centimeters of vessel, with vessel sections having 180° bends, 90° bends, and 360° bends in rapid succession. In the case of pulmonary embolism, access is through the venous system and then through the right atrium and right ventricle of the heart. The right ventricular outflow tract and pulmonary artery are delicate vessels that can be easily damaged by inflexible or high profile devices. For these reasons, it is desirable for a clot retrieval device to be compatible with guide catheters that are as low profile and flexible as possible.

[0004] Second, the vasculature in the area where the clot may be lodged is often fragile and delicate. For example, the vessels of the neurovasculature are more fragile than similarly sized vessels in other parts of the body and lie in soft tissue beds. Excessive pulling forces applied to these vessels can result in perforation and bleeding. Although the pulmonary vessels are larger than those of the cerebral vasculature, they are also inherently delicate, especially the more distal pulmonary vessels.

[0005] Third, clots can include any of a range of morphologies and consistencies. Long strings of softer clot material tend to clog in bifurcations or trifurcations, which can result in simultaneous occlusion of multiple vessels over significant lengths. More mature and organized clot material can be less compressible than softer new clots and, under the action of blood pressure, can distend the flexible vessels in which it is lodged. Furthermore, the inventors have discovered that the properties of a clot can be significantly altered by the action of a device interacting with it. Specifically, clot compression causes dehydration of the clot, resulting in a dramatic increase in both the clot's hardness and coefficient of friction. Summary of the Invention [Problem to be solved by the invention]

[0006] Any device must overcome the challenges discussed above to provide a high level of success in removing clots and restoring flow. Existing devices do not adequately address these challenges, particularly those associated with vascular trauma and clot characteristics. [Means for solving the problem]

[0007] It is the object of the present design to provide devices and methods that meet the above needs. Accordingly, it is desirable for a clot retrieval device to remove blood clots from the cerebral arteries of patients suffering from AIS, from the native coronary or graft vessels of patients suffering from MI, from the pulmonary arteries of patients suffering from pulmonary embolism, and from other peripheral arteries and veins where a blood clot is causing an obstruction.

[0008] In some embodiments, a clot retrieval device for removing a clot from a blood vessel is disclosed. The device can include a collapsed configuration and an expanded configuration. The device can include an inner expandable body having a framework of struts. The device can include an outer expandable body having a framework of struts forming closed cells larger than the closed cells of the inner expandable body and at least partially radially surrounding the inner expandable body. The outer expandable body can include a distal scaffold zone having a plurality of distally tapering struts having smaller closed cells within the outer expandable body than cells proximal thereto. The plurality of closed cells of the distal scaffold zone can be smaller than the axially aligned struts formed by the struts of the distal scaffold zone. Diamond a first plurality of closed cells, each of which is a cell of a shape; and a second plurality of closed cells, each of which is larger than the cells of the first plurality of closed cells and radially separated by a smaller number of closed cells. Diamond The cells of the shape can include a second plurality of closed cells radially inward and distal to each of the second plurality of closed cells, and a third plurality of closed cells radially separated and proximal to each of the second plurality of closed cells.

[0009] In some examples, the first plurality of closed cells can include a different shape than the second plurality of cells. The second plurality of closed cells can include a different shape than the third plurality of closed cells.

[0010] In some examples, the distal scaffold zone can be a protective strut structure that can include at least 12 closed cells between the first plurality of closed cells, the second plurality of closed cells, and the third plurality of closed cells.

[0011] In some embodiments, the first plurality of closed cells is formed by struts of the distal portion and includes a pair of axially aligned smaller closed cells positioned along upper and lower regions of the distal scaffold zone. Diamond It can contain cells of the shape.

[0012] In some embodiments, each Diamond The shaped cells may have a best fit diameter of approximately 1.2 mm.

[0013] In some embodiments, the second plurality of closed cells can include at least four cells.

[0014] In some embodiments, the at least four cells can have a best fit diameter of approximately 1.6 mm.

[0015] In some embodiments, each of the at least four cells is smaller Diamond It can only share one common edge with one of the shape's cells.

[0016] In some embodiments, each of the at least four cells may be pentagonal.

[0017] In some examples, the third plurality of radially separated cells can include at least five radially separated cells proximal to the second plurality of cells.

[0018] In some embodiments, the struts of the distal scaffold zone are connected to the inner expandable body.

[0019] In some embodiments, the struts in the distal scaffold zone form a mesh-like structure.

[0020] In some examples, the distal scaffold zone can have a porosity that is greater than the porosity provided by the struts of the outer expandable body proximal to it.

[0021] In some embodiments, a clot retrieval device for removing a clot from a blood vessel is disclosed. The device can include a collapsed configuration and an expanded configuration. The device can include an inner expandable body having a framework of struts. The device can include an outer expandable body having a framework of struts at least partially radially surrounding the inner expandable body. A distal portion of the outer expandable body extends toward the outer expandable body to a greater extent than the inner expandable body in the deployed configuration, and the closed cells of the distal portion are distally tapered and smaller within the outer expandable body than their proximal counterparts. The plurality of closed cells of the distal portion are formed by struts of the distal portion and include a pair of axially aligned smaller closed cells positioned along upper and lower regions of the distal portion. Diamond It can contain cells of the shape.

[0022] In some embodiments, the distal portion is a protective strut structure that can include at least 12 closed cells of the plurality of closed cells.

[0023] The plurality of closed cells in the distal portion can include at least four radially separated larger cells, with each smaller Diamond The shaped cells are radially inward and distal to at least four radially separated larger cells.

[0024] In some embodiments, the at least four radially separated larger cells can have a best fit diameter of approximately 1.6 mm.

[0025] Each of the at least four radially separated larger cells is a smaller Diamond It shares only one common edge with one of the shape's cells.

[0026] In some embodiments, each of the at least four radially separated larger cells forms a pentagon.

[0027] The plurality of closed cells in the distal portion can include at least five radially separated cells proximal to at least four radially separated larger cells.

[0028] In some examples, the strut framework of the outer expandable body can include a plurality of discontinuous expandable members spaced apart from adjacent expandable members, and each expandable strut can form a closed cell with at least some of the struts terminating in radially separated distal apexes that have no connection to adjacent closed cells.

[0029] In some examples, the device can include multiple clot entrance openings between each expandable body, through which the clot can pass and enter the device.

[0030] In some embodiments, each member can include at least four radiopaque markers equally radially spaced about the longitudinal axis of the outer expandable body.

[0031] In some embodiments, the at least four radiopaque markers are spaced approximately 10 mm apart in the folded configuration.

[0032] In some embodiments, the at least four radiopaque markers are spaced approximately 8 mm apart in the expanded configuration.

[0033] In some examples, the radiopaque markers of the at least four radiopaque markers can include a radiopaque material positioned within the eyelet.

[0034] The radiopaque markers of the at least four radiopaque markers may include at least one of barium sulfate, bismuth subcarbonate, barium oxychloride, gold, tungsten, platinum, iridium, tantalum, or alloys of these materials.

[0035] In some embodiments, the device can include at least three longitudinally spaced apart expandable members.

[0036] In some embodiments, the multiple closed cells of the distal portion form a distal mesh, the inner expandable body can include a closed distal portion, the distal portion of the outer expandable body is closed, and the distal portions of the outer and inner expandable bodies are together configured to prevent distal exit of a clot or clot fragments from the device.

[0037] In some embodiments, the outer expandable body is expandable to a greater radial extent than the inner expandable body so as to define a clot receiving space eccentrically disposed about the longitudinal axis of the outer tubular body.

[0038] In some embodiments, the outer expandable body can include a closed distal portion.

[0039] In some embodiments, the plurality of distal struts of the closed distal portion are helical.

[0040] In some embodiments, the plurality of distal struts of the closed distal portion extend perpendicular to the longitudinal axis of the outer expandable body.

[0041] In some embodiments, the plurality of distal struts of the closed distal portion are arranged in a raised or flared pattern.

[0042] In some embodiments, the outer and inner expandable bodies are each monolithic structures.

[0043] In some examples, the outer expandable body can include at least two longitudinally spaced apart expandable members connected by one or more struts configured as longitudinal hinges between the spaced apart expandable members, and each expandable member can include a plurality of radially separated radiopaque markers.

[0044] In some embodiments, each marker is positioned at a junction between at least two connecting struts of a respective expandable member.

[0045] In some embodiments, each member can include at least four radiopaque markers equally radially spaced about the longitudinal axis of the outer expandable body.

[0046] In some embodiments, the device can include at least three longitudinally spaced apart expandable members.

[0047] In some examples, the radiopaque marker can include a radiopaque material positioned within the eyelet.

[0048] In some examples, the radiopaque marker can include at least one of barium sulfate, bismuth subcarbonate, barium oxychloride, gold, tungsten, platinum, iridium, tantalum, or alloys of these materials.

[0049] In some embodiments, the diameter of the flow path in the expanded configuration is less than 50% of the diameter of the outer expandable body in the expanded configuration along the longitudinally extending clot receiving space between the inner expandable body and the outer expandable body.

[0050] In some embodiments, the device can include a shaft extending proximally of the proximal end of the inner and / or outer expandable body.

[0051] In some examples, the device can include struts at the distal portion connected to the inner expandable body.

[0052] Other aspects and features of the present disclosure will become apparent to those of ordinary skill in the art from the following detailed description considered in conjunction with the accompanying figures. [Brief description of the drawings]

[0053] The above and further aspects of the present disclosure are further considered in conjunction with the following description of the accompanying drawings, in which like numerals in various drawings indicate like structural elements and features. The drawings are not necessarily to scale, instead, emphasis is placed on illustrating the principles of the present disclosure. The figures depict one or more implementations of the device of the present invention, merely by way of example and not by way of limitation. It is expected that those skilled in the art can conceive and combine elements from multiple drawings to better meet the needs of users. [Figure 1] 1 shows an isometric view of a clot retrieval device of the present disclosure. [Diagram 2] 1 illustrates an isometric view of another embodiment of a clot retrieval device of the present disclosure. [Diagram 3] FIG. 2 shows a side view of the device of FIG. 1. [Figure 4A] FIG. 3 shows a side view of the outer member of the clot retrieval device of FIGS. 1-2. [Figure 4B] FIG. 3 shows a plan view of the outer member of the clot retrieval device of FIGS. 1-2. [Diagram 5] 2 shows an enlarged view of section AA of FIG. 1. [Figure 6]4 shows an enlarged view of section BB of FIG. 3. [Figure 7] 4 shows an enlarged view of section CC of FIG. [Figure 8] 4 shows an enlarged view of section DD of FIG. [Figure 9] 2 shows an enlarged isometric view of a distal region of the exemplary clot retrieval device of FIG. 1. [Figure 10A] 10 shows an end view of the distal region of FIG. 9. [Figure 10B] FIG. 10 shows an isometric view of the distal region of FIG. [Figure 10C] 10 shows a plan view of the distal region of FIG. 9. [Figure 11A] 1 illustrates a close-up isometric view of an exemplary marker. [Figure 11B] FIG. 11B shows a side view of the exemplary marker of FIG. [Figure 12] 14 illustrates a close-up view of an exemplary outer member on-expandable member in a folded configuration showing an exemplary laser cutting pattern. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] Specific embodiments of the present disclosure will now be described in detail with reference to the drawings, where like reference numbers indicate functionally similar or identical elements. The embodiments address many of the deficiencies associated with conventional catheters, such as inefficient clot removal and inaccurate deployment of the catheter to the target site.

[0055] Accessing various blood vessels in the vasculature, whether coronary, pulmonary, or cerebral, involves well-known procedural steps and the use of numerous conventional, commercially available accessory products. These products, such as angiographic contrast agents and guidewires, are widely used in examination and medical procedures. When these products are used with the systems and methods of the present disclosure in the following description, their functions and exact configurations will not be described in detail.

[0056] The following detailed description is merely exemplary in nature and is not intended to limit the disclosure or the application and uses of the disclosure. Although the disclosure is described mostly in the context of treating intracranial arteries, the disclosure may also be used in other body conduits as mentioned above.

[0057] While specific embodiments of the present disclosure have been illustrated and described, it will be apparent from the above description that various changes may be made without departing from the spirit and scope of the present disclosure. For example, while the embodiments described herein refer to certain features, the present disclosure includes embodiments having different combinations of features. The present disclosure also includes embodiments that do not include all of the specific features described. Specific embodiments of the present disclosure are described in detail below with reference to the drawings, in which like reference numbers indicate identical or functionally similar elements. The terms "distal" or "proximal" are used in the following description with reference to a position or direction relative to the treating physician. "Distal" or "distally" refers to a position away from or a direction away from the physician. "Proximal" or "proximal" or "proximal" refers to a position close to or a direction toward the physician.

[0058] Accessing the cerebral, coronary and pulmonary veins involves the use of numerous commercially available products and conventional procedure steps. Access products such as guidewires, guide catheters, angiography catheters and microcatheters are described elsewhere and are routinely used in catheterization procedures. In the following description, these products and methods are assumed to be used in conjunction with the devices and methods of the present disclosure and need not necessarily be described in detail. The detailed description below is merely exemplary in nature and is not intended to limit the present disclosure or its application and use. Although the description of the present disclosure is often in the context of treating intracranial arteries, the present disclosure may also be used in other body conduits as previously mentioned. A common theme throughout many of the disclosed designs is a double layered structure in which the device comprises an outer expandable member within which extends an inner expandable member, both members connected directly or indirectly to an elongated shaft, with a distal net or scaffold configured at the distal end of the device to prevent the escape of clot fragments. This distal net may be attached to either the shaft, the inner member or the outer member, or to some of these. As described throughout this document, a range of designs is contemplated for each of these elements, and it is intended that any of these elements can be used with any other element, although to avoid repetition, these elements have not been shown in all possible combinations.

[0059] For example, both the inner and outer expandable members are desirably made of a material that can automatically recover its shape when released from a significantly distorted delivery configuration. Particularly suitable are superelastic materials such as Nitinol or alloys with similar properties. The material can be in many forms, such as wire or strip or sheet or tube. A particularly suitable manufacturing process is to laser cut a Nitinol tube, then heat treat and electropolish the resulting structure to create a framework of struts and connecting elements. This framework can be in any of a wide variety of shapes as disclosed herein, and may be visualized under fluoroscopy through the addition of alloying elements (e.g., platinum, etc.) or through various other coatings or marker bands. The inner expandable member may optionally form a generally tubular structure, and is ideally configured to expand to a diameter smaller than the diameter of the smallest blood vessel in which it is intended to be used. This diameter is typically less than 50% of the diameter of the outer expandable member, and can be as small as 20% or less of the outer member diameter. A variety of different distal scaffold zone designs have been disclosed, some of which incorporate strut elements from the outer and / or inner expandable member frameworks, some of which incorporate thin wires or fibers to provide added scaffolding with minimal impact on the overall device profile or deliverability. Suitable materials ideally have high tensile strength so that very thin wires or fibers can be manufactured with sufficient integrity for manufacturability and use, such as polymeric materials such as UHMWPE, aramid, LCP, PET, or PEN, or metals such as tungsten, MP35N, stainless steel, or nitinol.

[0060] FIG. 1 illustrates an embodiment of a clot retrieval device 100 having an outer expandable member 102 and an inner expandable member 103 to facilitate restoration of blood flow through a clot immediately after the device 100 is deployed at an occlusion site. As illustrated, the member 102 can include four expandable members proximal to the distal portion. However, any number of expandable members is contemplated. For example, FIG. 2 illustrates a modified device 100' having fewer expandable member portions of the member 102 (e.g., two as illustrated). FIG. 3 illustrates a side view of the device 100 without a proximal shaft. The device 100 has an elongated shaft 106 having a distal end that extends inside the artery and a proximal end that extends outside the artery. The members 102 and 103 have a collapsed configuration for delivery and an expanded configuration for clot retrieval, blood flow restoration, and fragmentation protection. The member 103 can have a generally tubular body portion.

[0061] Member 103 is configured to self-expand to a diameter greater than that of member 102 upon release from a constraining sheath (e.g., a microcatheter). Expansion of member 102 can cause compression and / or displacement of the expanding clot. When the expandable body provides a high level of scaffolding, the clot is compressed. When the expandable body provides an escape route or opening, the expanding body urges the clot towards the opening. However, if the expandable body provides only moderate scaffolding, the clot is displaced but can move in a variety of different directions because the clot has many degrees of freedom and therefore cannot be controlled. By providing a tubular expandable body whose length is substantially greater than or equal to the length of the occlusive clot, many of the degrees of freedom of movement available to the clot are removed.

[0062] Members 102 and 103 may specifically have a collapsed configuration for delivery and an expanded configuration for blood flow restoration and fragmentation protection. Members 102, 103 may be joined at the proximal and distal ends during assembly to minimize tension within members 102, 103 during use. In other embodiments, member 103 may not be connected at all to the distal end of member 103, or may be constrained within member 102 without being fixedly attached. In other embodiments, member 103 may have a non-cylindrical cross-section, may be non-uniform in diameter, and may have a strut pattern tailored to provide different radial forces or regions of flexibility. The length of member 102 may be substantially the same as the length of member 103 in the freely expanded configuration and in the loaded collapsed configuration.

[0063] Member 103 may have an elastic or superelastic or shape memory metal structure and may have a polished surface, such as an electropolished surface. Member 103 may be configured to provide a flow lumen or flow path (e.g., a generally cylindrical cross-section) through device 100 to facilitate restoration of blood flow through the clot upon deployment. In one embodiment, member 103 is configured to provide a scaffold in the flow path through the clot to prevent dislodging of fragments that may otherwise become lodged in the distal vasculature. Member 103 may include one or more connected struts 131 configured to contact the clot when initially deployed within a target vessel within the clot. Contact of one or more struts 131 with the clot provides additional grip and aids in the initial removal of the clot from the vessel as device 100 is retracted.

[0064] The distal end of the member 103 may include an expandable portion formed of expanded struts 110 having a diameter larger than that of the member 103. These expanded struts 110 may be connected to a coil portion 118 (see, e.g., FIG. 8) that may be laser cut from a tube from which the member 103 may also be cut. The coil 118 may also be configured to accommodate small length differences by stretching without applying significant tensile or compressive forces to the device 100. The coil 118 may be formed from a stainless steel material, a polymer, or a more radiopaque metal such as gold or platinum, or an alloy of such materials. The coil 118 may be replaced with a longitudinal length of a resilient material such as a low modulus polymer or elastomer. The distal end of the coil 118 may be bonded (e.g., by an adhesive, solder, welding, or brazing process) to the distal collar 109 of the member 102. In some embodiments, struts 110 can elongate during loading, such that the lengths of members 102, 103 are equal when fully loaded into the microcatheter. A difference in length between members 102 and 103 may still occur when device 100 is deployed in a small vessel or during the loading or deployment process.

[0065] Members 102 and 103 are preferably made of a superelastic or pseudoelastic material such as Nitinol or another such alloy with high recoverable strain. Shaft 106 may be a tapered wire shaft and may be made of stainless steel, MP35N, Nitinol, or other material with suitably high elastic modulus and tensile strength. Shaft 106 may have an indicator band 107 to indicate when the distal end of device 100 is approaching the end of the microcatheter during insertion. Shaft 106 may have a coil 104 adjacent its distal end and proximal to members 102, 103. Coil 104 may be metallic and may be formed of stainless steel or a more radiopaque material such as platinum or gold, or an alloy of such material. In another embodiment, coil 104 may be coated with a low friction material or may have a polymer jacket positioned on the outer surface of coil 104. A sleeve 105 may be positioned on shaft 106 adjacent to coil 104. The sleeve 105 may be polymeric and may be positioned over the tapered portion of the shaft 106. The sleeve 105 may be made radiopaque by adding a filler material such as tungsten or barium sulfate. However, other radiopaque materials are contemplated, including, but not limited to, bismuth subcarbonate, barium oxychloride, gold, platinum, iridium, tantalum, or alloys of any of these materials. The sleeve 105 and shaft 106 may be coated with a material that reduces friction and thrombogenicity. The coating may include a polymer, a low-friction lubricant such as silicone, a hydrophilic or hydrophobic coating. This coating may also be applied to the members 102 and 103.

[0066] FIG. 4A shows a side view of the member 102, and FIG. 4B shows a plan view of the member 102. An inlet opening 122 is provided in the member 102, whereby the inlet 122 can provide the primary degree of freedom of movement available to the clot, such that expansion of the member 102 urges the clot into the receiving space 111. The member 102 can have multiple inlet openings 122 for receiving the clot. The inlet openings 122 can be configured to allow portions of the clot to enter the receiving space 111, thus allowing the clot to be retrieved without being overly compressed. This is advantageous because the inventors have discovered that compression of the clot dehydrates the clot, but in turn increases the frictional properties of the clot and increases its stiffness, all of which make it more difficult for the clot to break away from the blood vessel and be removed. This compression can be avoided if the clot moves inward through the wall of the member 102 as the porous structure moves outward toward the vessel wall.

[0067] Entrance opening 122 can also provide the added benefit of allowing member 102, as it is retracted, to apply a force to the clot in a direction substantially parallel to the direction the clot is pulled from the vessel (i.e., substantially parallel to the central axis of the vessel). This means that the outward radial force applied to the vasculature can be kept to a minimum, which in turn means that the action of clot retrieval device 100 on the clot does not increase the force required to remove the clot from the vessel, thereby protecting the delicate cerebral vessels from harmful radial and tensile forces.

[0068] As shown, member 102 can include proximal struts 120 connected at its proximal end to collar 112 and at its distal end to first expandable member 126, which is shown more clearly in FIG. 6 at section BB, and may have a tapered profile to ensure a gradual stiffness transition from shaft 106 to the clot engaging portion of the device. Member 126 can be connected to second expandable member 127 by a number of connecting arms 129, which can extend from a proximal junction 139 to a distal junction 140. Arms 129 can include generally straight struts that extend parallel to the central axis of the device. In other embodiments, these connecting arms can comprise a number of struts arranged in one or more cells, or can comprise curved or spiral arms. The region between the first and second expandable members has two entrance openings 122 through which the blood clot can pass and enter the receiving space 111 defined by the region between the inner and outer members.

[0069] Member 127 can then be connected to third expandable member 128 by a connecting arm 130 that extends from proximal joint 141 to distal joint 142. Arm 130 can include a generally straight strut that extends parallel to a central axis of device 100. In other embodiments, arm 130 can include a plurality of struts arranged in one or more cells, or can include a curved or spiral arm. The region between members 127 and 128 can include one or more entry openings 122 through which clots can pass and enter receiving space 111 defined by the region between members 102 and 103. Arm 129 between members 126 and 127 can be substantially aligned with arm 130 between members 127 and 128 to align the neutral axes of members 126, 127, 128 during bending. In other embodiments, arm 129 between members 126 and 127 may be aligned with arm 130 between members 127 and 128 at an angle, such as 90 degrees.

[0070] In some embodiments, member 126 may include interconnected struts, such as strut 143 terminating at crown 133 without a distal connection element, and other struts such as 144 terminating at junctions 145 and 146. The struts within the expandable member may be configured such that multiple crowns (e.g., crowns 145, 150) are not aligned at the same distance from proximal collar 112 during loading. During loading or resheathing, generally more force may be required to load a crown into a sheath than a strut. Thus, if multiple crowns are loaded simultaneously, the user may notice an increased loading force. By offsetting the crowns (e.g., crowns 145, 150) by making alternate struts 144 and 151 different lengths, the loading force may be reduced, improving perception to the user. Similarly, second expandable member 127 may include interconnected struts, such as strut 147 terminating at crown 134 without a distal connection element, and other struts (e.g., strut 148) terminating at a junction. Similarly, third expandable member 128 may include interconnected struts, such as strut 152 terminating at crown 135 without a distal connection element, and other struts terminating at a junction. Figure 7 shows a cross-sectional view of section CC of Figure 3, which more clearly shows member 128 and its struts (e.g., strut 152) and crown 135. As shown, fewer or more expandable members 126, 127, 128 may be included in member 102.

[0071] In some embodiments, the expandable member of the member 102 may include one or more markers 125 having a radiopaque material, such as, but not limited to, a radiopaque material such as gold, tungsten, tantalum, platinum, or alloys containing these or other high atomic number elements. Polymeric materials (e.g., polyurethane, pebax, nylon, polyethylene, etc.) containing radiopaque fillers such as barium sulfate, bismuth subcarbonate, barium oxychloride, gold, tungsten, platinum, iridium, tantalum, alloys of these materials, and / or adhesives filled with radiopaque fillers may also be used. In this regard, the markers 125 may be included as eyelets on the struts throughout the member 102. The markers 125 may be positioned to indicate to the user the distal end of the barrel of the member 102 to aid in accuracy of deployment. The distal end of the member 102 may include a circumferential ring of struts 123 connected to a series of struts 124, which may terminate at a distal junction 109 that may include a collar. In some embodiments, members 102 can terminate in a closed distal end, while in other aspects, the distal end of members 102 can be open or not necessarily closed. In some embodiments, struts 124 can have a generally conical shape, as shown. In some embodiments, struts 124 can be configured in a generally planar shape, which can be inclined or perpendicular to the longitudinal axis of device 100. Struts 124 and 149 can taper to a width narrower than the width of the more proximal struts, including the body of the expandable members (e.g., members 126, 127, 128, etc.), thus creating a gradual transition in the stiffness of the device in both the expanded and collapsed states.

[0072] 5 is an enlarged view of section AA of FIG. 1, more clearly showing the exemplary markers 125 staggered on and along members 126. It is understood that the locations of markers 125 shown in FIG. 7 and throughout this disclosure are merely exemplary, and that markers 125 may be included in other locations and features of device 100. In some examples, markers 125 may be spaced approximately 10 mm apart in the collapsed delivery configuration and approximately 8 mm apart in the expanded configuration. However, markers 125 are not so limited and may be separated as needed or desired.

[0073] FIG. 8 shows a close-up view of section DD of FIG. 3, more clearly showing the distal region 155, and FIG. 9 shows a close-up isometric view of the distal region 155 (sometimes interchangeably referred to herein as the distal scaffold zone) of the device 100 at section EE of FIG. 3. FIG. 10A (end view) and FIG. 10B (isometric view) show only the distal region 155 of the member 102, where the three-dimensional distal mesh of region 155 is configured to create a fragment protection feature with a framework of struts. As shown, a plurality of apexes or crowns 184 of the distal region 155 shown in FIGS. 9-10C are provided connected to a plurality of arms 182 proximal thereto, which terminate at a junction adjacent the collar 109. The arms 182 may be shaped as needed or desired, including generally arcuate or conical as shown. Preferably, arms 182 form a plurality of closed cells that progress progressively from larger closed cells at or adjacent to the proximal end of region 155 to smaller closed cells at or adjacent to the distal end. In some embodiments, at least 12 closed cells may be provided in distal region 155 of device 100. The illustrated distal region 155 may include a closed distal end of member 102, which, together with a mesh formed by arms 182 and corresponding closed cells of region 155, may prevent the exit of a clot or clot fragment that has entered the aforementioned receiving space 111 between members 102 and 103.

[0074] In some embodiments, the axially aligned smaller Diamond Cells 187 of a shape may be formed by the arms 182 and positioned along the upper and lower regions of the distal mesh. In some embodiments, at least two cells 187 are provided. Larger cells 189 may be positioned radially about the longitudinal axis L of the device 100 and radially inward of the cells 187. In some embodiments, at least four cells 189 are provided joined at or adjacent to the junction proximate the collar 109. In some embodiments, the cells 189 may be approximately 1.2 mm in size, which measurement is the size of the best fit diameter of a circle placed within each cell (e.g., the illustrated cells 187 depicted in plan view in FIG. 10C). In other embodiments, the cells 189 may be larger (e.g., approximately 1.6 mm).

[0075] Cells 186 may also be provided proximal to cells 187, 189. In some embodiments, at least five cells 186 radially separated about axis L may be positioned proximal to cells 187, 189. Each of cells 186 may include a strut common to cells 187, 189 as well as crown 184. In some embodiments, the proximal strut of each of cells 186 may be arcuate or otherwise curved. In some embodiments, distal region 155 illustrated in FIGS. 9-10C may be a monolithic structure integrally formed with a region of member 102 proximal thereto (e.g., by laser machining from the same tube as the remainder of member 102). In some embodiments, radiopaque coil 108 (e.g., formed of platinum, gold, alloys, etc.) may be positioned distal to distal region 155 configured to couple to or against distal collar 109.

[0076] Fig. 11A shows an enlarged isometric view of an exemplary marker 125, and Fig. 11B shows a side view of the marker 125. The illustrated marker 125 is generally formed of platinum-iridium, although, as previously mentioned, other radiopaque materials are contemplated as needed or desired.

[0077] FIG. 12 shows a close-up view of the expandable member 127 in a folded configuration, showing an exemplary laser cut pattern with enhanced visibility. It is understood that the other expandable members of the member 102 can follow the same or similar pattern. The member 12 may include three staggered eyelet cuts for the markers 125. In other embodiments, the member 12 may include four staggered eyelet cuts for the markers 125. Fewer or more eyelet cuts can be included as needed or desired to incorporate markers 125. In those embodiments having four eyelet cuts, each expandable member of the member 102 can include four markers 125. In this regard, if the member 102 had three expandable members, the member 102 can include at least twelve markers 125 in total staggered throughout. If the member 102 had four expandable members, at least twenty markers 125 can be included in the member 102 staggered throughout.

[0078] The present disclosure is not limited to the described examples, which may vary in configuration and details. The terms "distal" and "proximal" are used throughout the foregoing description and are meant to refer to a location and direction relative to the treating physician. Thus, "distal" or "distally" refers to a location away from the physician or a direction away from the physician. Similarly, "proximal" or "proximally" refers to a location closer to the physician or a direction toward the physician.

[0079] In the description of the embodiments, technical terms are used for clarity. Each term is intended to have its broadest meaning as understood by those skilled in the art, and is intended to include all technical equivalents that operate in a similar manner to achieve a similar purpose. It should also be understood that the reference to one or more steps of a method does not exclude the presence of additional method steps or intervening method steps between those steps that are explicitly identified. Each step of the method can be performed in a different order than that described herein without departing from the scope of the disclosed technology. Similarly, it should also be understood that the reference to one or more components in a device or system does not exclude the presence of additional components or intervening components between those components that are explicitly identified.

[0080] As discussed herein, a "patient" or "subject" can be a human or any animal. It should be understood that the animal can be of any of a variety of relevant types, including, but not limited to, mammals, veterinary animals, livestock animals, or pet animals. As an example, the animal can be a laboratory animal (e.g., rats, dogs, pigs, monkeys, etc.) that is specifically selected to have certain characteristics similar to humans.

[0081] The term "about" or "approximately" as used herein with respect to any numerical value or range of numerical values ​​indicates a suitable dimensional tolerance that allows a portion of a component or a collection of components to function according to its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value, e.g., "about 90%" may refer to a range of values ​​of 71% to 99%. Ranges may be expressed herein as "about" or "approximately" one particular value to "about" or "approximately" another particular value. When expressing such a range, other exemplary embodiments also include one particular value to the other particular value.

[0082] "Comprising" or "containing" or "including" means that at least the specified compounds, elements, particles, or method steps are present in a composition or article or method, but does not exclude the presence of other such compounds, substances, particles, or method steps, even if those other compounds, substances, particles, or method steps have the same function as the one specified.

[0083] It should also be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0084] The descriptions contained herein are examples of the present disclosure and are not intended to limit the scope of the present disclosure in any way. Although specific examples of the present disclosure have been described, various modifications to the devices and methods can be made without departing from the scope and spirit of the present disclosure. For example, the examples described herein refer to specific components, but the present disclosure includes other embodiments that utilize combinations of various components to achieve the described functionality, utilize alternative materials to achieve the described functionality, combine components from various embodiments, combine components from various embodiments with known components, and the like. The present disclosure contemplates the replacement of component parts exemplified herein with other known commercially available products. These modifications will be apparent in many cases to those skilled in the art to which the present disclosure pertains, and are intended to be within the scope of the following claims.

[0085] [Embodiment] (1) A clot retrieval device for removing a blood clot from a blood vessel, the device having a collapsed configuration and an expanded configuration; an inner expandable body comprising a framework of struts; an outer expandable body comprising a framework of struts forming larger closed cells than the closed cells of the inner expandable body and at least partially radially surrounding the inner expandable body, the distal scaffold zone comprising a plurality of distally tapering struts having smaller closed cells than those proximal thereto within the outer expandable body; a plurality of closed cells of the distal scaffold zone comprising: Axially aligned smaller struts formed by the struts of the distal scaffold zone. Diamond a first plurality of closed cells, the cells being of the shape; a second plurality of closed cells, each of the smaller cells being larger than the first plurality of closed cells and radially separated from each other; Diamond a second plurality of closed cells having a cell of a shape radially inward and distal to each of the second plurality of closed cells; a third plurality of closed cells radially separated and proximal to each of the second plurality of closed cells. (2) the first plurality of closed cells has a different shape than the second plurality of cells; 2. The device of embodiment 1, wherein the second plurality of closed cells has a different shape than the third plurality of closed cells. (3) The device of embodiment 1, wherein the distal scaffold zone is a protective strut structure comprising at least 12 closed cells between the first plurality of closed cells, the second plurality of closed cells, and the third plurality of closed cells. (4) the first plurality of closed cells are formed by struts of a distal portion and include a pair of axially aligned smaller closed cells positioned along upper and lower regions of the distal scaffold zone; Diamond 2. The device of embodiment 1, which is a cell shaped device. (5) each Diamond 5. The device of embodiment 4, wherein the cells of the shape have a best fit diameter of approximately 1.2 mm.

[0086] (6) The device of embodiment 4, wherein the second plurality of closed cells comprises at least four cells. (7) The device of embodiment 6, wherein the at least four cells have a best fit diameter of approximately 1.6 mm. (8) Each of the at least four cells is smaller than the Diamond 7. The device of embodiment 6, which shares only one common edge with one of the cells of the shape. (9) The device of embodiment 6, wherein each of the at least four cells is pentagonal. (10) The device of embodiment 6, wherein the third plurality of radially separated cells includes at least five radially separated cells proximal to the second plurality of cells.

[0087] (11) A clot retrieval device for removing a blood clot from a blood vessel, the device having a collapsed configuration and an expanded configuration; an inner expandable body comprising a framework of struts; an outer expandable body comprising a framework of struts at least partially radially surrounding the inner expandable body; a distal portion of the outer expandable body extends toward the outer expandable body to a greater extent than the inner expandable body in a deployed configuration, and closed cells of the distal portion are distally tapered and smaller than their proximal cells within the outer expandable body; The plurality of closed cells of the distal portion are formed by struts of the distal portion and include a pair of axially aligned smaller closed cells positioned along upper and lower regions of the distal portion. Diamond A clot retrieval device comprising a cell of the shape. (12) The device of embodiment 11, wherein the distal portion is a protective strut structure comprising at least 12 closed cells of the plurality of closed cells. (13) The plurality of closed cells of the distal portion includes at least four radially separated larger cells, and each smaller Diamond12. The device of embodiment 11, wherein the shaped cells are radially inward and distal to the at least four radially separated larger cells. (14) The device of embodiment 13, wherein the at least four radially separated larger cells have a best fit diameter of approximately 1.6 mm. (15) each of said at least four radially separated larger cells is a smaller Diamond 14. The device of embodiment 13, which shares only one common edge with one of the cells of the shape.

[0088] (16) The device of embodiment 13, wherein each of the at least four radially separated larger cells is pentagonal. (17) The device of embodiment 13, wherein the plurality of closed cells of the distal portion includes at least five radially separated cells proximal to the at least four radially separated larger cells. (18) The device of embodiment 11, wherein the strut framework of the outer expandable body comprises a plurality of discontinuous expandable members spaced apart from adjacent expandable members, each expandable strut forming a closed cell with at least some struts terminating in radially separated distal apexes with no connection to adjacent closed cells, and each member comprising at least four radiopaque markers equally radially separated about the longitudinal axis of the outer expandable body. (19) The device of embodiment 18, wherein the at least four radiopaque markers are spaced approximately 10 mm apart in the folded configuration. (20) The device of claim 18, wherein the at least four radiopaque markers comprise at least one of barium sulfate, bismuth subcarbonate, barium oxychloride, gold, tungsten, platinum, iridium, tantalum, or alloys of these materials.

Claims

1. 1. A clot retrieval device for removing a blood clot from a blood vessel, the device having a collapsed configuration and an expanded configuration; an inner expandable body comprising a framework of struts; an outer expandable body comprising a framework of struts forming larger closed cells than the closed cells of the inner expandable body and at least partially radially surrounding the inner expandable body, the distal scaffold zone comprising a plurality of distally tapering struts having smaller closed cells than those proximal thereto within the outer expandable body; a plurality of closed cells of the distal scaffold zone comprising: a first plurality of closed cells being axially aligned smaller diamond shaped cells formed by struts of the distal scaffold zone; a second plurality of closed cells larger than the cells of the first plurality of closed cells and spaced apart radially, each smaller diamond shaped cell being radially inward and distal to each of the second plurality of closed cells; a third plurality of closed cells radially separated and proximal to each of the second plurality of closed cells.

2. the first plurality of closed cells having a different shape than the second plurality of cells; The device of claim 1 , wherein the second plurality of closed cells comprises a different shape than the third plurality of closed cells.

3. 10. The device of claim 1, wherein the distal scaffold zone is a protective strut structure comprising at least 12 closed cells between the first plurality of closed cells, the second plurality of closed cells, and the third plurality of closed cells.

4. 10. The device of claim 1, wherein the first plurality of closed cells is a pair of axially aligned smaller diamond shaped cells formed by struts of a distal portion and positioned along upper and lower regions of the distal scaffold zone.

5. 5. The device of claim 4, wherein each diamond shaped cell has a best fit diameter of approximately 1.2 mm.

6. The device of claim 4 , wherein the second plurality of closed cells comprises at least four cells.

7. The device of claim 6 , wherein the at least four cells have a best fit diameter of approximately 1.6 mm.

8. The device of claim 6 , wherein each of the at least four cells shares only one common edge with one of the smaller diamond-shaped cells.

9. The device of claim 6 , wherein each of the at least four cells is pentagonal.

10. The device of claim 6 , wherein the third plurality of radially separated cells includes at least five radially separated cells proximal to the second plurality of cells.

11. 1. A clot retrieval device for removing a blood clot from a blood vessel, the device having a collapsed configuration and an expanded configuration; an inner expandable body comprising a framework of struts; an outer expandable body comprising a framework of struts at least partially radially surrounding the inner expandable body; a distal portion of the outer expandable body extends toward the outer expandable body to a greater extent than the inner expandable body in a deployed configuration, and closed cells of the distal portion are distally tapered and smaller than their proximal cells within the outer expandable body; A clot retrieval device, wherein the plurality of closed cells of the distal portion include a pair of axially aligned smaller diamond shaped cells formed by struts of the distal portion and positioned along upper and lower regions of the distal portion.

12. The device of claim 11 , wherein the distal portion is a protective strut structure comprising at least 12 closed cells of the plurality of closed cells.

13. 12. The device of claim 11, wherein the plurality of closed cells of the distal portion includes at least four radially separated larger cells, each smaller diamond shaped cell being radially inward and distal to the at least four radially separated larger cells.

14. 14. The device of claim 13, wherein the at least four radially separated larger cells have a best fit diameter of approximately 1.6 mm.

15. 14. The device of claim 13, wherein each of the at least four radially separated larger cells shares only one common edge with one of the smaller diamond shaped cells.

16. The device of claim 13 , wherein each of the at least four radially separated larger cells is pentagonal.

17. The device of claim 13 , wherein the plurality of closed cells of the distal portion includes at least five radially separated cells proximal to the at least four radially separated larger cells.

18. 12. The device of claim 11, wherein the strut framework of the outer expandable body comprises a plurality of discontinuous expandable members spaced apart from adjacent expandable members, each expandable strut forming a closed cell with at least some struts terminating in radially separated distal apexes with no connections to adjacent closed cells, and each member comprising at least four radiopaque markers equally radially separated about the longitudinal axis of the outer expandable body.

19. 20. The device of claim 18, wherein the at least four radiopaque markers are spaced approximately 10 mm apart in the folded configuration.

20. 20. The device of claim 18, wherein the at least four radiopaque markers comprise at least one of barium sulfate, bismuth subcarbonate, barium oxychloride, gold, tungsten, platinum, iridium, tantalum, or alloys of these materials.

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