Clot retrieval device for removing clots from blood vessels

Abstract

The invention is entitled "Clot retrieval device for removing clots from blood vessels." A clot retrieval device for removing clots from blood vessels is disclosed. The device can include a collapsed configuration and an expanded configuration. The device can include an inner inflatable body having a strut frame. The device can include an outer inflatable body having a strut frame at least partially radially surrounding the inner inflatable body. A distal portion of the outer inflatable body can extend to a greater extent toward the outer inflatable body than the inner inflatable body in a deployed configuration, the closed cells of the distal portion tapering distally and being smaller than the cells proximal thereto in the outer inflatable body. The plurality of closed cells of the distal portion can include a pair of axially aligned smaller diamond cells formed by struts of the distal portion and positioned along an upper region and a lower region of the distal portion.

Description

Technical Field

[0001] The present invention relates generally to apparatus and methods for removing blockages from blood vessels during intravascular medical treatment. Background Technology

[0002] Clot retrieval devices are frequently used in mechanical thrombectomy involving endovascular intervention in patients with conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). Acute obstructions can include clots, misaligned devices, migrating devices, large emboli, etc. Thromboembolism occurs when a thrombus partially or completely detaches from the vessel wall. This clot (now called an embolus) then travels in the direction of blood flow. If the clot remains in the cerebral vascular system, it can lead to ischemic stroke. If the clot originates in the venous system or the right side of the heart and remains in the pulmonary artery or its branches, it can lead to pulmonary embolism. Clots can also not be released as emboli but instead form locally and block vessels; this mechanism is more common in the formation of coronary artery occlusions. Designing clot removal devices that provide a high level of performance presents significant challenges. First, there are many access challenges that make device delivery difficult. In cases where access involves navigating the aortic arch (such as in coronary or cerebral occlusions), the arch configuration in some patients makes it difficult to locate the guiding catheter. These difficult arch configurations are classified as type 2 or type 3 aortic arches, with type 3 arches presenting the greatest difficulty.

[0003] In arteries near the brain, the challenges of tortuosity are even more pronounced. For example, in the distal end of the internal carotid artery, it is not uncommon for the device to navigate rapidly and continuously through segments of the vessel with 180°, 90°, and 360° bends within a few centimeters of blood. In the case of pulmonary embolism, access is obtained via the venous system and then through the right atrium and ventricle of the heart. The right ventricular outflow tract and the pulmonary artery are fragile vessels that are easily damaged by inflexible or high-profile devices. For these reasons, it is desirable for clot retrieval devices to be compatible with the lowest possible profile and most flexible guiding catheter.

[0004] Secondly, the vascular system in the area where clots may become lodged is typically fragile and delicate. For example, neurovascular systems are more delicate than vessels of similar size in other parts of the body and are located in soft tissue beds. Excessive tension applied to these vessels can lead to perforation and bleeding. Pulmonary vessels are larger than those in the cerebral vascular system, but they are also delicate, especially the more distal vessels.

[0005] Third, clots can comprise any of a range of morphologies and consistencies. Longer strands of softer clot material may tend to remain at bifurcation or trifurcation points, resulting in multiple vessels being simultaneously obscured over a significant length. More mature and organized clot material may be less compressible than softer, fresher clots, and under the influence of blood pressure, it may cause compliant vasodilation of the vessels containing the material. Furthermore, the inventors have discovered that the properties of clots can be significantly altered by the action of the device interacting with them. Specifically, compression of blood clots leads to clot dehydration and a significant increase in clot stiffness and coefficient of friction.

[0006] Any device needs to overcome the challenges described above to deliver a high level of success in clot removal and blood flow restoration. Existing devices are not adequately able to address these challenges, especially those associated with vascular trauma and clot properties. Summary of the Invention

[0007] The object of the present invention is to provide an apparatus and method that meet the above-mentioned needs. Therefore, it is desirable for a clot retrieval device to remove clots from the cerebral arteries of patients with AIS, the coronary arteries of patients with MI (myocardial infarction) who have been born or transplanted, the pulmonary arteries of patients with PE, and other peripheral arteries and veins that are occluded by clots.

[0008] In some examples, a clot retrieval device for removing clots from a blood vessel is disclosed. The device may include a collapsed configuration and an expanded configuration. The device may include an inner expandable body with a strut frame. The device may include an outer expandable body with a strut frame forming closed units larger than those of the inner expandable body and at least partially radially surrounding the inner expandable body. The outer expandable body may include a distal support frame region having a plurality of struts tapering distally, each having a closed unit smaller than that of its proximal counterpart in the outer expandable body. The plurality of closed units in the distal support frame region may include: a first plurality of closed units being axially aligned smaller rhomboid units formed by the struts of the distal support frame region; a second plurality of closed units larger than and radially separated from the units in the first plurality of closed units, each smaller rhomboid unit being radially inward and located distal to each of the closed units in the second plurality of closed units; and a third plurality of closed units radially separated and located proximal to each of the closed units in the second plurality of closed units.

[0009] In some examples, the first plurality of closed units may include shapes different from those of the plurality of second units. The second plurality of closed units may include shapes different from those of the third plurality of closed units.

[0010] In some examples, the distal support frame area may be a protective strut structure, which may include at least twelve closed units located between a first plurality of closed units, a second plurality of closed units, and a third plurality of closed units.

[0011] In some examples, the first plurality of closed units may include a pair of axially aligned smaller diamond-shaped units formed by struts of the distal portion and positioned along the upper and lower regions of the distal support frame area.

[0012] In some examples, each rhomboid unit may have an optimal mating diameter of approximately 1.2 mm.

[0013] In some examples, the second plurality of closed units may include at least four units.

[0014] In some examples, the at least four units may have an optimal mating diameter of approximately 1.6 mm.

[0015] In some examples, each of the at least four cells may share only one common edge with one of the smaller rhombus cells.

[0016] In some examples, each of the at least four cells can be a pentagon.

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

[0018] In some examples, the struts in the distal support frame area are connected to the internal expandable body.

[0019] In some examples, the struts in the distal support area form a mesh-like structure.

[0020] In some examples, the distal support frame region may include a porosity greater than that provided by the plurality of struts of the external expandable body on its proximal side.

[0021] In some examples, a clot retrieval device for removing clots from a blood vessel is disclosed. The device may include a collapsed configuration and an expanded configuration. The device may include an inner expandable body with a strut frame. The device may include an outer expandable body with a strut frame that at least partially radially surrounds the inner expandable body. A distal portion of the outer expandable body may extend toward the outer expandable body in a deployment configuration to a greater extent than the inner expandable body, with the closure units of the distal portion tapering distally and smaller than their proximal units in the outer expandable body. The plurality of closure units of the distal portion may include a pair of axially aligned smaller rhomboid units formed by the struts of the distal portion and positioned along the upper and lower regions of the distal portion.

[0022] In some examples, the distal portion is a protective strut structure that may include at least twelve closed units out of a plurality of closed units.

[0023] In some examples, the multiple closed units of the distal portion may include at least four radially separated larger units, each smaller rhomboid unit being radially inward and located distal to the at least four radially separated larger units.

[0024] In some examples, at least four radially separated larger units may have an optimal mating diameter of approximately 1.6 mm.

[0025] In some examples, each of at least four radially separated larger cells shares only one common edge with one of the smaller rhombus cells.

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

[0027] In some examples, the multiple closed units of the distal portion may include at least five radially separated units located proximal to at least four radially separated larger units.

[0028] In some examples, the strut frame of the external expandable body may include a plurality of discontinuous expandable members spaced apart from adjacent expandable members, each expandable member having struts that can form closed units, wherein at least some struts terminate at radially separated distal vertices that are not connected to adjacent closed units.

[0029] In some examples, the device may include a plurality of clump inlets located between respective expandable bodies, through which clumps may pass and enter the device.

[0030] In some examples, each component may include at least four radiopaque markers that are equally radially separated about the longitudinal axis of the outer expandable body.

[0031] In some examples, at least four radiopaque markers are separated by about 10 mm in the collapsed configuration.

[0032] In some examples, at least four radiopaque markers are separated by about 8 mm in the bulging configuration.

[0033] In some examples, at least four radiopaque markers may include radiopaque material positioned within the aperture.

[0034] In some examples, 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 examples, the device may include at least three longitudinally spaced expandable members.

[0036] In some examples, multiple closed units of the distal portion form a distal mesh; the inner expandable body may include a closed distal portion, and the distal portion of the outer expandable body is closed; and the distal portions of the outer expandable body and the inner expandable body are configured together to prevent clots or clot fragments from flowing out of the distal side of the device.

[0037] In some examples, the outer expandable body can expand to a greater radial extent than the inner expandable body to define a clump receiving space eccentrically arranged around the longitudinal axis of the outer tubular body.

[0038] In some examples, the external expandable body may include a closed distal portion.

[0039] In some examples, the multiple distal struts of the closed distal portion are spiral-shaped.

[0040] In some examples, multiple distal struts of the closed distal portion extend perpendicular to the longitudinal axis of the external expandable body.

[0041] In some examples, multiple distal struts of the closed distal portion are configured as raised or expanded patterns.

[0042] In some examples, the outer expandable body and the inner expandable body are each an integral structure.

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

[0044] In some examples, each marker is positioned at the joint between at least two connecting struts of the corresponding expandable member.

[0045] In some examples, each component may include at least four radiopaque markers that are equally radially separated about the longitudinal axis of the outer expandable body.

[0046] In some examples, the device may include at least three longitudinally spaced expandable members.

[0047] In some examples, the radiopaque marker may include radiopaque material positioned within the aperture.

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

[0049] In some examples, the diameter of the flow channel in the expansion configuration is less than 50% of the diameter of the clot receiving space extending longitudinally between the inner and outer expandable bodies in the expansion configuration.

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

[0051] In some examples, the device may include a strut attached to the distal portion of the internal expandable body.

[0052] 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

[0053] The above and other aspects of this disclosure will be further discussed with reference to the accompanying drawings, in which like numbers indicate the same structural elements and features in the various figures. The drawings are not necessarily drawn to scale, but rather focus on illustrating the principles of this disclosure. The drawings depict one or more specific embodiments of the apparatus of the invention by way of example only and not by way of limitation. It is expected that those skilled in the art will be able to conceive and combine elements from the various drawings to better meet the needs of the user.

[0054] Figure 1 An isometric view of the clot retrieval apparatus of this disclosure is shown.

[0055] Figure 2 An isometric view of another example of the clot retrieval apparatus of this disclosure is shown.

[0056] Figure 3 It shows Figure 1 A side view of the device.

[0057] Figure 4A It shows Figures 1 to 2 Side plan view of the external components of the clot retrieval device.

[0058] Figure 4B It shows Figures 1 to 2 Top plan view of the external components of the clot retrieval device.

[0059] Figure 5 It shows Figure 1 A close-up view of section AA.

[0060] Figure 6 It shows Figure 3 A close-up view of section BB.

[0061] Figure 7 It shows Figure 3 A close-up view of the cross section CC.

[0062] Figure 8 It shows Figure 3 A close-up view of the cross section DD.

[0063] Figure 9 It shows Figure 1 A close-up isometric view of the distal region of an exemplary clot retrieval device.

[0064] Figure 10A It shows Figure 9 End view of the far side region.

[0065] Figure 10B It shows Figure 9 An isometric view of the far side region.

[0066] Figure 10C It shows Figure 9 A top view of the far side of the area.

[0067] Figure 11A A close-up isometric view of an exemplary marker is shown.

[0068] Figure 11B It shows Figure 11A A side plan view of an exemplary marker.

[0069] Figure 12 A close-up of an expandable member of an exemplary external member in a collapsed configuration is shown, illustrating an exemplary laser-cut pattern. Detailed Implementation

[0070] Specific examples of this disclosure will now be described in detail with reference to the accompanying drawings, wherein like reference numerals denote functionally similar or identical elements. These examples address many drawbacks associated with conventional catheters, such as inefficient clot removal and inaccurate catheter deployment to the target site.

[0071] Approaching various intravascular vessels (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 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 systems and methods of this disclosure described below.

[0072] The following detailed descriptions are merely exemplary in nature and are not intended to limit the scope or application of this disclosure. While the description of this disclosure is in the context of treating intracranial arteries in many cases, it can also be used in other bodily channels as described above.

[0073] As will be apparent from the foregoing description, while specific embodiments of this disclosure have been illustrated and described, various modifications may be made without departing from the spirit and scope of this disclosure. For example, while the embodiments described herein relate to specific feature structures, this disclosure includes embodiments with combinations of different feature structures. This disclosure also includes embodiments that do not include all the specific feature structures described. Specific embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, wherein like reference numerals denote like or functionally similar elements. The terms “distal” or “proximal” are used below in the description of position or direction relative to the treating physician. “Distal” or “towards distal” means a position away from the physician or in a direction away from the physician. “Proximal” or “towards proximal” or “in proximal” means a position close to the physician or in a direction toward the physician.

[0074] Access to cerebral, coronary, and pulmonary vessels involves the use of numerous commercially available products and routine procedural steps. Access products such as guidewires, guiding catheters, angiography catheters, and microcatheters are described elsewhere and are commonly used in catheterization laboratory procedures. The description below assumes that these products and methods are used in conjunction with the apparatus and methods of this disclosure and do not require detailed description. The following detailed description is merely exemplary in nature and is not intended to limit this disclosure or its application and use. While the description of this disclosure is in the context of treating intracranial arteries in many instances, this disclosure can also be used in other bodily accesses as described above. A common theme in many of the disclosed designs is a two-layer construction in which the device includes an outer expandable member, an inner expandable member extending within the outer expandable member, both members being directly or indirectly connected to an elongated shaft, and the device including a distal mesh or support frame configured to prevent the escape of clot fragments at the distal end of the device. This distal mesh may be attached to the shaft, the inner or outer members, or several of them. As described in this document, a range of designs are envisioned for each of these elements, and any of these elements can be used in combination with any other element, but to avoid repetition, they are not shown in any possible combinations.

[0075] For example, both the internal and external expandable members are advantageously made of a material that can automatically recover its shape once released from a highly strain-delivered configuration. Hyperelastic materials such as nitinol or alloys with similar properties are particularly suitable. This material can be in various forms, such as wires, strips, sheets, or tubes. A particularly suitable manufacturing process is laser-cutting of the nitinol tube, followed by heat setting and electropolishing of the resulting structure to form a framework of struts and connecting elements. This framework can be any of the wide range of shapes disclosed herein and can be visible under fluoroscopic examination by adding alloying elements (e.g., platinum) or by various other coatings or marking strips. In some cases, the internal expandable member can be formed into a generally tubular structure and ideally configured to expand to a diameter smaller than the diameter of the smallest vessel it is intended to be used in. This diameter is typically less than 50% of the diameter of the external expandable member and can be as low as 20% or less of the external member's diameter. This invention discloses a series of different distal support frame designs, some of which incorporate strut elements from the frame of external and / or internal expandable members, and some of which incorporate fine wires or fibers to provide an added support frame with minimal impact on the overall device shape or deliverability. Suitable materials ideally possess high tensile strength, allowing for the production of ultrafine wires or fibers with sufficient integrity for manufacturability and use, such as polymeric materials like UHMWPE, aramid, LCP, PET, or PEN, or metals like tungsten, MP35N, stainless steel, or nickel-titanium.

[0076] Figure 1 An embodiment of a clot retrieval device 100 is shown, which has an external expandable member 102 and an internal expandable member 103 to facilitate the immediate restoration of blood flow through the clot after the device 100 has been deployed at the obstructive site. As shown, member 102 may include four (4) expandable members located proximally on the distal portion. However, any number of expandable members is conceivable. For example, Figure 2 A modified device 100' with fewer expandable component segments (e.g., two (2) as shown in the figure) having component 102 is shown. Figure 3 The side view of device 100 is shown, but the proximal shaft is not shown. Device 100 has an elongated shaft 106 having a distal end extending inside the artery and a proximal end extending outside the artery. Components 102 and 103 have a collapse configuration for delivery and an expansion configuration for clot retrieval, flow restoration, and / or fragmentation protection. Component 103 may have a generally tubular body segment.

[0077] Component 103 is configured to self-expand to a diameter greater than that of component 102 upon release from the restraint sheath (e.g., a microcatheter). The expansion of component 102 can cause compression and / or displacement of the clot during expansion. When the expandable body provides a high level of support, the clot is compressed. When the expandable body provides an escape path or opening, the expanding body will push the clot toward the opening. However, if the expandable body only provides modest support, the clot will displace, but because the clot has many degrees of freedom, it can move in a variety of different directions and therefore cannot be controlled. By providing a tubular expandable body, wherein the length of the tubular expandable body is substantially the same as or longer than the length of the occluded clot, many of the clot's available degrees of freedom of movement are removed.

[0078] Components 102 and 103 may specifically have a collapsed configuration for delivery and an expanded configuration for flow recovery and fragmentation protection. Components 102 and 103 may engage at their proximal and distal ends during assembly to minimize tension within components 102 and 103 during use. In other examples, component 103 may not be attached to its distal end at all, or may be constrained within component 102 without being fixedly attached. In other examples, component 103 may have a non-cylindrical cross-section, its diameter may be non-uniform, and it may have a custom strut pattern to provide areas with different radial forces or flexibility. The length of component 102 may be substantially the same as the length of component 103 in both its free expanded and loaded collapsed configurations.

[0079] Component 103 may have a resilient, hyperelastic, or shape-memory metal structure and may have a polished surface, such as an electropolished surface. Component 103 may be configured to provide a flow lumen or flow channel (e.g., a generally cylindrical segment) through device 100 to facilitate the restoration of blood flow through the clot upon deployment. In one embodiment, component 103 is configured to bridge the flow channel through the clot to prevent the release of fragments that might otherwise remain lodged in the distal vascular system. Component 103 may include one or more connected struts 131 configured to contact the clot upon initial deployment into a target blood vessel within the clot. The contact of the one or more struts 131 with the clot provides additional gripping and facilitates initial displacement of the clot from the blood vessel upon retraction of device 100.

[0080] The distal end of component 103 may include an expandable segment formed by expansion struts 110 with a diameter greater than that of component 103. These expansion struts 110 may be connected to coil segments 118 (see, for example...). Figure 8The coil segment can be laser-cut from component 103 or from its cut tube. Coil 118 can also be configured to accommodate small length differences by stretching without applying significant tension or compressive force to device 100. Coil 118 can be formed from stainless steel, polymer, or less radiopaque metals such as gold or platinum or alloys of such materials. Coil 118 can be replaced with a longitudinally elastomer, such as a low-modulus polymer or elastomer. The distal end of coil 118 can be (e.g., by adhesive, solder, welding, or brazing processes) joined to the distal retainer 109 of component 102. In some examples, the support bar 110 can elongate during loading so that the lengths of components 102 and 103 are equal when fully loaded into the microcatheter. Length differences between components 102 and 103 may still occur when device 100 is deployed in a small blood vessel or during loading or deployment.

[0081] Components 102 and 103 are preferably made of a hyperelastic or pseudoelastic material, such as nitinol or another such alloy having high recoverable strain. Shaft 106 may be a tapered spool and may be made of stainless steel, MP35N, nitinol, or other materials with suitable high modulus and tensile strength. Shaft 106 may have an indicator band 107 to indicate when the distal end of device 100 approaches the end of the microcatheter during insertion. Shaft 106 may have a coil 104 adjacent to its distal end and proximal to components 102, 103. Coil 104 may be metallic and may be formed of stainless steel or a less radiopaque material (such as platinum or gold or alloys of such materials). In other examples, coil 104 may be coated with a low-friction material or have a polymer sheath on the outer surface of coil 104. Adjacent to coil 104, sleeve 105 may be positioned on shaft 106. Sleeve 105 may be polymer and may be positioned over the tapered segment of shaft 106. Sleeve 105 can be made radiopaque by adding filler materials 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 any alloy of these materials. Sleeve 105 and shaft 106 may be coated with materials to reduce friction and thrombotic activity. The coating may include polymers, low-friction lubricants such as silicone, hydrophilic coatings, or hydrophobic coatings. The coating may also be applied to components 102 and 103.

[0082] Figure 4A A side plan view of component 102 is shown, while Figure 4BA top plan view of component 102 is shown. An inlet opening 122 is provided in component 102, thereby providing the main degrees of freedom of movement available to the clot, and thus expansion of component 102 causes the clot to enter receiving space 111. Component 102 may have multiple inlets 122 to receive clots. Inlets 122 may be configured to allow portions of the clot to enter receiving space 111, thereby allowing the clot to be retrieved without excessive compression. This is advantageous because the inventors have found that compression of the clot dehydrates it, which in turn increases the clot's frictional properties and its stiffness, all of which make the clot more difficult to detach from and remove from the blood vessel. Such compression can be avoided if the clot migrates inward through the wall of component 102 as it migrates outward toward the vessel wall of the porous structure.

[0083] The inlet 122 also provides the additional benefit of allowing the member 102 to apply force to the clot in a direction substantially parallel to the direction in which the clot is pulled out of the blood vessel (i.e., substantially parallel to the central axis of the blood vessel) when retracted. This means that the outward radial force applied to the vascular system can be kept to a minimum, which in turn means that the action of the clot retrieval device 100 on the clot is not used to increase the force required to remove the clot from the blood vessel, thereby protecting the fragile cerebral blood vessels from harmful radial and tensile forces.

[0084] As shown in the figure, component 102 may include a proximal support 120, which is connected to a retaining ring 112 at its proximal end and to a first expandable component 126 at its distal end. Figure 6 The cross-section BB is shown more clearly. As shown, the strut 120 may have a tapered profile to ensure a gradual stiffness transition from shaft 106 to the lumpy joint segment of the device. Member 126 can be connected to the second expandable member 127 via a plurality of connecting arms 129 extending from the proximal joint 139 to the distal joint 140. Arms 129 may include generally straight struts extending parallel to the central axis of the device. In other embodiments, these connecting arms may include a plurality of struts constructed in one or more units, or may include curved or helical arms. The region between the first and second expandable members includes two inlets 122 through which the lumpy can pass and enter a receiving space 111 defined by the region between the inner and outer members.

[0085] Component 127 can then be connected to a third expandable component 128 via a connecting arm 130 extending from the proximal joint 141 to the distal joint 142. Arm 130 may include a generally straight strut extending parallel to the central axis of device 100. In some examples, arm 130 may include multiple struts constructed in one or more units, or may include a curved or helical arm. The region between components 127, 128 may include one or more inlets 122 through which the clump can pass and enter a receiving space 111 defined by the region between components 102, 103. Arm 129 between components 126, 127 may be substantially aligned with arm 130 between components 127, 128 to align the neutral axes of components 126, 127, 128 during bending. In other examples, arm 129 between components 126, 127 may be aligned with arm 130 between components 127, 128 at an angle such as 90 degrees.

[0086] In some examples, component 126 may include interconnecting struts such as strut 143 terminating at crown 133 without a distal connecting element, and other struts such as 144 terminating at mating points 145 and 146. The struts in the expandable component may be configured such that during loading, multiple crowns (e.g., crowns 145, 150) are not aligned at the same distance from the proximal retainer 112. During loading or re-insertion, a higher force than that required by the struts may typically be needed to load the crowns into the sheath. Therefore, if multiple crowns are loaded simultaneously, the user may notice an increase in loading force. By offsetting the crowns (e.g., crowns 145, 150) with alternative struts 144 and 151 of different lengths, the loading force can be reduced and the user's perception improved. Similarly, the second expandable component 127 may include interconnecting struts such as strut 147 terminating at crown 134 without a distal connecting element, and other struts terminating at mating points (e.g., strut 148). Similarly, the third expandable member 128 may include interconnecting struts such as strut 152 terminating at the crown 135 without a distal connecting element, and other struts terminating at the joint. Figure 7 It shows Figure 3 A close-up view of section CC, which more clearly shows member 128 and its struts (e.g., strut 152) and crown 135. As shown, member 102 may include fewer or larger expandable members 126, 127, 128.

[0087] In some examples, the expandable component of component 102 may include one or more markers 125 having a radiopaque material, such as, but not limited to, radiopaque materials such as gold, tungsten, tantalum, platinum, or alloys containing these or other high atomic number elements. Polymer materials (e.g., polyurethane, polyether block amide, nylon, polyethylene, etc.) may also be used, containing radiopaque fillers such as barium sulfate, bismuth subcarbonate, barium oxychloride, gold, tungsten, platinum, iridium, tantalum, alloys of these materials, and / or binders filled with radiopaque fillers. In this respect, markers 125 may be included throughout component 102 as eyelets on the struts. Markers 125 may be positioned to indicate to the user the distal end of a cylindrical segment of component 102 to aid in deployment accuracy. The distal end of component 102 may include a circumferential ring of struts 123 connected to a series of struts 124 terminating at a distal engagement point 109, which may include a retaining ring. In some examples, member 102 may terminate at a closed distal end, while in others, the distal end of member 102 may be open or not necessarily closed. In some examples, strut 124 may include a generally conical shape, as shown. In some examples, strut 124 may be arranged in a generally flat plane, which may be inclined or perpendicular to the longitudinal axis of device 100. Straps 124 and 149 may taper to a width narrower than the width of the strut closer to the body including expandable members (e.g., members 126, 127, 128, etc.), thereby creating a gradual transition in the stiffness of the device in both the expanded and collapsed states.

[0088] Figure 5 yes Figure 1 A close-up view of section AA, which more clearly shows the exemplary markings 125 intersecting on and along member 126. It should be understood that, as Figure 7 The location of the marker 125 shown throughout this disclosure is merely exemplary, and the marker 125 may be included elsewhere and have other features of the device 100. In some examples, the marker 125 may be separated by about 10 mm in a collapsed delivery configuration and by about 8 mm in an expanded configuration. However, the marker 125 is not limited thereto and may be separated as needed or required.

[0089] Figure 8 It shows Figure 3 A close-up view of section DD, which more clearly shows the distal region 155, while Figure 9 It shows Figure 3 A close-up isometric view of the distal region 155 (sometimes interchangeably referred to here as the distal support frame region) of the device 100 at section EE. Figure 10A (End view) and Figure 10BThe isometric view shows only the distal region 155 of member 102, where the three-dimensional distal mesh of region 155, constructed for debris protection features, is generated by a strut frame. As shown in the figure... Figures 9 to 10C Multiple vertices or crowns 184 of the distal region 155 shown are configured to connect to multiple arms 182 proximally to them, the arms terminating at the joint adjacent to the retaining ring 109. The arms 182 may be shaped as needed or required, including generally arcuate or conical shapes as shown. Preferably, the arms 182 form multiple closure units that gradually transition from larger closure units at or near the proximal end of region 155 to smaller closure units at or near the distal end. In some examples, at least twelve closure units may be provided in the distal region 155 of device 100. The distal region 155 shown may include a closed distal end of member 102, which, together with the mesh formed by the arms 182 and corresponding closure units of region 155, prevents the outflow of clumps or clump fragments that have entered the receiving space 111 between the previously described members 102, 103.

[0090] In some examples, smaller, axially aligned diamond-shaped cells 187 may be formed by arms 182 and positioned along the upper and lower regions of the distal mesh. In some examples, at least two cells 187 are provided. Larger cells 189 may be radially positioned about the longitudinal axis L of the device 100 and radially inwardly positioned along the cells 187. In some examples, at least four cells 189 are provided to engage at or near the joint of the retaining ring 109. In some examples, cells 189 may be measured to be approximately 1.2 mm, the measurement being placed in the corresponding cell (e.g., in...). Figure 10C The optimal fitting diameter of the circle in unit 187 is shown in the top view. In other examples, unit 189 may be measured larger (e.g., approximately 1.6 mm).

[0091] Unit 186 may also be located proximal to units 187, 189. In some examples, at least five (5) units 186 radially separated about axis L may be positioned proximal to units 187, 189. Each unit in unit 186 may include a strut shared with units 187, 189 and crown 184. In some examples, the proximal strut of each unit in unit 186 may be arcuate or otherwise curved. In some examples, Figures 9 to 10C The distal region 155 shown may be an integral structure formed on the same side as the region proximal to the member 102 (e.g., by laser processing of the same tube as the rest of the member 102). In some examples, a transmissive coil 108 (e.g., formed of platinum, gold, alloy, etc.) may be positioned distal to the distal region 155, which is configured to be coupled at or against the distal retaining ring 109.

[0092] Figure 11A A close-up isometric view of exemplary marker 125 is shown, while Figure 11B A side plan view of marker 125 is shown. Marker 125 is typically formed of platinum-iridium, but as previously mentioned, other radiopaque materials may be envisioned as needed or required.

[0093] Figure 12 A close-up of the expandable member 127 in a collapsed configuration is shown, illustrating an exemplary laser-cut pattern with enhanced visibility. It should be understood that other expandable members of member 102 may follow the same or similar pattern. Member 12 may include three (3) eyelet cuts staggered for markers 125. In other examples, member 12 may include four (4) eyelet cuts staggered for markers 125. Fewer or more eyelet cuts may be included to incorporate markers 125 as needed or required. In those examples with four eyelet cuts, each expandable member of member 102 may include four markers 125. In this respect, if member 102 will have three expandable members, member 102 may include a total of at least twelve markers 125 staggered throughout. If member 102 will have four expandable members, at least twenty markers 125 may be included, wherein member 102 staggered throughout.

[0094] This disclosure is not limited to the examples described, 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 closer to the physician or in a direction toward the physician.

[0095] In describing the examples, terminology is used for clarity. It is intended that each term 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. It should also be understood that 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. The steps of a method may be performed in an order different from that described herein without departing from the scope of the disclosed art. 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.

[0096] As discussed herein, a “patient” or “individual” can be a person or any animal. It should be understood that an animal can be any applicable type, including but not limited to mammals, veterinary animals, livestock, or pets. For example, an animal can be a laboratory animal specifically selected to have certain characteristics similar to humans (e.g., rats, dogs, pigs, monkeys, etc.).

[0097] 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 elements to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of enumerated values ​​±20%, for example, “about 90%” may refer to a range of values ​​from 71% to 99%. A range may be expressed herein as “about” or “approximately” for one particular value and / or “about” or “approximately” for another particular value. Other exemplary embodiments when expressing such ranges include from one particular value and / or to another particular value.

[0098] "Comprising," "containing," or "including" means that at least the named compound, element, particle, or method step is present in the composition, article, or method, but does not exclude the presence of other compounds, materials, particles, or method steps, even if the other such compounds, materials, particles, or method steps have the same function as the named ones.

[0099] It should also be noted that, unless the context clearly indicates otherwise, the singular forms “a” and “the” used in this specification and the appended claims include plural references.

[0100] The descriptions contained herein are examples of this disclosure and are not intended to limit the scope of this disclosure in any way. While specific examples of this disclosure have been described, various modifications may be made to the apparatus and methods without departing from the scope and spirit of this disclosure. For example, while the examples described herein relate to specific components, this disclosure includes other examples of achieving the function using various combinations of components, achieving the function using alternative materials, combining components of the various examples, combining components of the various examples with known components, etc. This disclosure contemplates replacing the components shown herein with other well-known and commercially available products. These modifications will generally be apparent to those skilled in the art to which this disclosure pertains and are intended to fall within the scope of the following claims.

Claims

1. A clot retrieval device for removing clots from a blood vessel, the device comprising a collapsed configuration and an expanded configuration and including: An internally expandable body, the internally expandable body including a strut frame forming a closed unit; as well as An external expandable body includes a closure unit that forms a closure unit larger than that of the internal expandable body and a strut frame that radially surrounds the internal expandable body at least partially. The external expandable body includes a distal support frame region that includes a plurality of struts that taper distally and have closure units smaller than those of the proximal units in the external expandable body. The plurality of closed units in the distal support frame area include: The first plurality of closed units are small diamond-shaped units axially aligned by the struts of the distal support frame area; A second plurality of pentagonal closed units, the second plurality of pentagonal closed units being larger than the units in the first plurality of closed units and radially separated, each small rhomboid unit being radially inwardly disposed on the far side of the second plurality of pentagonal closed units and adjacent to the second plurality of pentagonal closed units; and, A third plurality of closed units, the third plurality of closed units being radially separated and located near each of the second plurality of pentagonal closed units; Wherein, each of the second plurality of pentagonal closed units shares a common edge with two units of the first plurality of closed units; and Each of the first plurality of closed units shares a common edge with two units of the second plurality of pentagonal closed units.

2. The apparatus according to claim 1, characterized in that, The first plurality of closed units include shapes different from the second plurality of pentagonal closed units; and The second plurality of pentagonal closed units include shapes different from those of the third plurality of closed units.

3. The apparatus according to claim 1, characterized in that, The distal support frame area is a protective support structure, which includes at least twelve closed units located between the first plurality of closed units, the second plurality of pentagonal closed units, and the third plurality of closed units.

4. The apparatus according to claim 1, characterized in that, The first plurality of closed units are a pair of axially aligned small diamond-shaped units, which are formed by the struts of the distal support frame area and positioned along the upper and lower regions of the distal support frame area.

5. The apparatus according to claim 4, characterized in that, Each diamond unit includes an optimal mating diameter of 1.2 mm.

6. The apparatus according to claim 4, characterized in that, The second plurality of pentagonal closed units include at least four units.

7. The apparatus according to claim 6, characterized in that, The at least four units include an optimal mating diameter of 1.6 mm.

8. The apparatus according to claim 6, characterized in that, Each of the at least four cells shares only one common edge with one of the small diamond cells.

9. The apparatus according to claim 6, characterized in that, The third plurality of closed units includes at least five radially separated units located near the second plurality of pentagonal closed units.

10. A clot retrieval device for removing clots from a blood vessel, the device comprising a collapsed configuration and an expanded configuration, and comprising: An internal expandable body, the internal expandable body including a support frame; and An external expandable body, the external expandable body including a strut frame that at least partially radially surrounds the internal expandable body; and The distal portion of the external expandable body extends radially outward in the expansion configuration, wherein the small rhomboid closed units of the distal portion taper distally and are smaller than the large pentagonal closed units adjacent to the proximal side of the small rhomboid closed units. The small rhomboid closed unit of the distal portion includes axially aligned units formed by the struts of the distal portion and positioned along the upper and lower regions of the distal portion. and Each small rhomboid closed unit shares a common edge with two units in the large pentagonal closed unit; and Each pentagonal large closed unit shares a common edge with two units in the small rhombus closed unit.

11. The apparatus according to claim 10, characterized in that, The distal portion is a protective support structure, which includes at least twelve closed units.

12. The apparatus according to claim 10, characterized in that, The pentagonal large closed unit of the distal portion includes at least four radially separated large units, each small rhomboid closed unit located radially inside and far from the at least four radially separated large units.

13. The apparatus according to claim 12, characterized in that, The at least four radially separated large units include an optimal mating diameter of 1.6 mm.

14. The apparatus according to claim 12, characterized in that, Each of the at least four radially separated large units shares only one common edge with one of the small rhomboid closed units.

15. The apparatus according to claim 12, characterized in that, The small rhomboid closed unit of the distal portion includes at least five radially separated units located proximal to the at least four radially separated large units.

16. The apparatus according to claim 10, characterized in that, The strut frame of the external expandable body includes a plurality of discontinuous expandable members spaced apart from adjacent expandable members. The struts of each expandable member form a closed unit, wherein at least some struts terminate at radially separated distal apexes that are not connected to adjacent closed units. Each member includes at least four radiopaque markers that are equally radially separated about the longitudinal axis of the external expandable body.

17. The apparatus according to claim 16, characterized in that, The at least four radiopaque markers are spaced 10 mm apart in the collapsed configuration.

18. The apparatus according to claim 16, characterized in that, The at least four radiopaque markers include at least one of barium sulfate, bismuth subcarbonate, barium oxychloride, gold, tungsten, platinum, iridium, tantalum, or alloys of these materials.

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