System and method for a double-layered, elongated blood clot recovery device

Abstract

To provide a blood clot recovery device. [Solution] A blood clot removal device comprising an outer cage, an inner cage positioned concentrically within the outer cage, a first elongated member communicating with the outer cage, and a second elongated member communicating with the inner cage. The first elongated member may be attached to the proximal end of the outer cage and may be configured to move the outer cage between a delivery configuration and an expansion configuration. The second elongated member may be attached to the proximal end of the inner cage and may be configured to move the inner cage between a delivery configuration and an expansion configuration.

Description

Technical Field

[0001] The present disclosure generally relates to devices and methods for removing obstructions from blood vessels during endovascular medical procedures.

Background Art

[0002] Thrombus retrieval devices are used for mechanical thrombus removal in endovascular interventions, particularly when a patient suffers from acute ischemic stroke (AIS), myocardial infarction (MI), pulmonary embolism (PE), etc. Acute occlusions can include thrombi, mispositioned devices, displaced devices, large emboli, etc. Thromboembolism occurs when part or all of a thrombus detaches from the vessel wall. This thrombus (herein referred to as an embolus) is then carried in the direction of blood flow. Ischemic stroke can result when a thrombus blocks the blood vessel system of the brain. Pulmonary embolism can result when a thrombus forms in the venous system or on the right side of the heart and lodges in the pulmonary artery or its branches. A thrombus can also develop in the form of an embolus without being released and locally block a blood vessel, and this mechanism is common in the formation of obstructions in the coronary arteries. There are significant challenges associated with the design of thrombus removal devices that can provide high levels of performance. First, there are many access-related challenges that make it difficult to deliver the device. When access involves navigating the aortic arch (such as in coronary artery occlusion or brain occlusion), the shape of the aortic arch in some patients makes it difficult to position the guiding 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 problem of tortuosity is even more serious in arteries approaching the brain. For example, it is not uncommon for a device to have to advance uninterrupted over several centimeters of vessels with 180° bends, 90° bends, and 360° bends in the distal end of the internal carotid artery. 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 rigid or high-profile devices. For these reasons, it is desirable that blood clot retrieval devices be compatible with guide catheters that are as low-profile and flexible as possible.

[0004] Secondly, vascular structures within areas where blood clots may be present are often fragile and delicate. For example, the blood vessels of the neurovascular system are more fragile than similarly sized vessels in other parts of the body and are located in a soft tissue bed. Excessive tensile force applied to these vessels can lead to perforation and bleeding. Pulmonary vessels are larger than those of the cerebrovascular system, but are also inherently more delicate, especially the more distal pulmonary vessels.

[0005] Thirdly, blood clots can encompass a range of morphology and consistency. Longer, string-like, softer blood clots may tend to block bifurcations or trifurcations, resulting in the simultaneous occlusion of multiple blood vessels over considerable lengths. More mature and organized blood clots may be less compressible than softer, newer clots, and under the action of blood pressure, they can expand the flexible blood vessels they occupy. Furthermore, the inventors have discovered that the properties of blood clots can be significantly altered by the action of devices interacting with them. Specifically, compression of a blood clot causes dehydration, resulting in a dramatic increase in both the stiffness and friction coefficient of the clot.

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

[0007] The objective of this design is to provide a device and method that meets the above needs. Therefore, it is desirable that the blood clot retrieval device removes blood clots from the cerebral arteries of patients suffering from AIS, from the natural coronary or transplanted vessels of patients suffering from MI, from the pulmonary arteries of patients suffering from pulmonary embolism, and from other peripheral arteries and veins where the blood clot is causing occlusion.

[0008] In some embodiments, the device includes a clamping function configured to be positioned close to the occlusion (e.g., within the internal carotid artery, ICA). The device may be configured to reperfuse the vessel and / or remove the blood clot with a fibrin core. In some embodiments, the fibrin core may be located in the middle or distal part of the blood clot surrounded by a relatively soft thrombus.

[0009] In some embodiments, the device may be configured to remove blood clots within the M1 branch.

[0010] In some embodiments, the device may be configured to remove blood clots within the M2 branch.

[0011] In some embodiments, a method for manufacturing a blood clot recovery device may include the steps of: patterning a first predetermined pattern on a first tube to form an outer cage, the first predetermined pattern including an outer diameter of the outer cage; patterning a second predetermined pattern on a second tube to form an inner cage including an inner channel; and positioning the inner cage concentrically within the outer cage. Additionally, the blood clot recovery device may include an expansion configuration having a diameter larger than the inner diameter of the microcatheter.

[0012] In some embodiments, the outer diameter of the first tube is approximately equal to the outer diameter of the blood clot recovery device in the expanded configuration, thereby allowing the outer cage to expand to a larger diameter below, around, or near the blood clot, or improving juxtaposition with the vessel wall, when both the blood clot recovery device and the outer cage have equal radial forces, compared to an outer cage with a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device.

[0013] In some embodiments, the outer diameter of the first tube is larger than the outer diameter of the blood clot recovery device in the expanded configuration, thereby allowing the outer cage to expand to a larger diameter below, around, or near the blood clot, or improving juxtaposition with the vessel wall, when both the blood clot recovery device and the outer cage have equal radial forces, compared to an outer cage with a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device.

[0014] In some embodiments, the outer cage may be patterned to include a ring of eight support posts.

[0015] In some embodiments, the inner cage may be patterned to include a ring of four posts configured to hold a portion of the blood clot.

[0016] In some embodiments, the method may further include the step of attaching a first radiopaque marker to the distal end of the outer cage and a second radiopaque marker to the proximal end of the outer cage.

[0017] In some embodiments, the method may further include the steps of: attaching a first elongated member to the proximal end of an outer cage, wherein the first elongated member is configured to move the outer cage between a delivery configuration and an expansion configuration; and attaching a second elongated member to the proximal end of an inner cage, wherein the second elongated member is configured to move the inner cage between a delivery configuration and an expansion configuration.

[0018] In some embodiments, the second elongated member may be a wire.

[0019] In some embodiments, the first elongated member may be a tube.

[0020] In some embodiments, the first elongated member may comprise a first plurality of segments, each of which segments can decrease its outer diameter to form a taper, the first elongated member may include a variable stiffness profile along the first elongated member, and the proximal end of the first elongated member may be stiffer than the distal end of the first elongated member.

[0021] In some embodiments, the second elongated member may comprise a plurality of first segments, each of which segments can decrease its outer diameter to form a taper, the second elongated member may have a variable stiffness profile along the second elongated member, and the proximal end of the second elongated member may be stiffer than the distal end of the second elongated member.

[0022] In some embodiments, the method further includes the step of attaching a second elongated member, which includes attaching the distal end of the second elongated member to the proximal end of the receptacle and attaching the proximal end of the inner cage into the cavity of the receptacle, wherein the second elongated member may be slidable within the lumen of the first elongated member.

[0023] In some embodiments, the receptacle may further include a step within the cavity to mitigate overinsertion of the proximal end of the inner cage.

[0024] In some embodiments, the method may further include the step of patterning a third predetermined pattern on the first elongated member in order to achieve a desired stiffness profile along the first elongated member.

[0025] In some embodiments, the third predetermined pattern can include one or more of a spiral pattern, one or more intermittent spiral patterns, or one or more radial cut patterns.

[0026] In some embodiments, the first elongate member and the second elongate member can be in separate lumens within the microcatheter.

[0027] In some embodiments, the method can further include decoupling the first elongate member and the second elongate member and advancing the microcatheter proximally over the inner cage such that the cells of the inner cage crush over the blood clot to exert additional pressure on portions of the blood clot or by engaging the blood clot between the distal end of the microcatheter and the cells of the inner cage.

[0028] In some embodiments, the method can further include attaching the proximal ends of the first elongate member and the second elongate member using clips that include C-shaped features and coupling the first elongate member and the second elongate member by sliding the first elongate member and the second elongate member distally or proximally together.

[0029] In some embodiments, a method for removing a blood clot can include positioning a microcatheter adjacent to the blood clot within a blood vessel wall, retracting the microcatheter in a proximal direction such that an outer cage and an inner cage within the lumen of the microcatheter expand around the blood vessel wall and engage a portion of the blood clot, reducing the distance between adjacent struts of the inner cage or struts of the outer cage to exert pressure on the portion of the blood clot engaged by the inner struts or outer struts, thereby sandwiching the blood clot, retracting a first elongate member in communication with the inner cage or a second elongate member in communication with the outer cage in a proximal direction, and advancing the microcatheter distally over one of the first elongate member or the second elongate member. Additionally, the method can include crushing the cells of the inner cage onto the blood clot to exert additional pressure on the portion of the blood clot or engaging a portion of the blood clot between the distal end of the microcatheter and the cells of the inner cage and advancing the microcatheter to sandwich a portion of the blood clot.

[0030] In some embodiments, the method can further include retracting the blood clot from the blood vessel wall with the microcatheter, the first elongate member, and the second elongate member, the inner cage, and the outer cage.

[0031] In some embodiments, the outer cage can be patterned to comprise a ring of eight struts.

[0032] In some embodiments, the inner cage can be patterned to comprise a ring of four struts configured to sandwich a portion of the blood clot.

[0033] In some embodiments, the step of positioning a microcatheter in close proximity to a blood clot may further include the step of joining the first and second elongated members using a clip that includes a C-shaped feature, by attaching the proximal ends of the first and second elongated members, respectively, using a C-shaped feature, and sliding the microcatheter and the first and second elongated members together to approach the blood clot.

[0034] In some embodiments, the step of retracting the first elongated member communicating with the inner cage may further include disconnecting the first elongated member and the second elongated member from each other so that the first elongated member can be retracted independently of the second elongated member.

[0035] In some embodiments, the second elongated member may be a tube.

[0036] In some embodiments, the first elongated member may be a wire.

[0037] In some embodiments, the first and second elongated members may be located within separate lumens of the first and second jackets within the microcatheter.

[0038] In some embodiments, the first elongated member may comprise a first plurality of segments, each of which segments can decrease its outer diameter to form a taper, the first elongated member may have a variable stiffness profile along the first elongated member, and the proximal end of the first elongated member may be stiffer than the distal end of the first elongated member.

[0039] In some embodiments, the second elongated member comprises a plurality of first segments, each of which segments can reduce its outer diameter to form a taper, the second elongated member can have a variable stiffness profile along the second elongated member, and the proximal end of the second elongated member is stiffer than the distal end of the second elongated member.

[0040] In some embodiments, the step of retracting the first elongated member communicating with the inner cage may further include sliding the first elongated member proximal or distal within the lumen of the second elongated member.

[0041] In some embodiments, a third predetermined pattern can be patterned on the second elongated member in order to achieve a desired stiffness profile along the second elongated member.

[0042] In some embodiments, the third predetermined pattern may include one or more of the following: a helical pattern, one or more intermittent helical patterns, or one or more radial cut patterns.

[0043] In some embodiments, the blood clot recovery device may comprise an outer cage, an inner cage positioned concentrically within the outer cage, a first elongated member communicating with the outer cage, and a second elongated member communicating with the inner cage.

[0044] In some embodiments, the outer diameter of the outer cage can be made approximately equal to the outer diameter of the blood clot recovery device in an expanded configuration, thereby allowing the outer cage to be expanded to a larger diameter below, around, or near the blood clot, or improving juxtaposition with the vessel wall, when both the blood clot recovery device and the outer cage have equal radial forces, compared to an outer cage with a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device.

[0045] In some embodiments, the outer diameter of the outer cage can be made larger than the outer diameter of the blood clot recovery device in the expanded configuration, thereby allowing the outer cage to expand to a larger diameter below, around, or near the blood clot, or improving juxtaposition with the vessel wall, when both the blood clot recovery device and the blood clot recovery device have equal radial forces, compared to an outer cage with a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device.

[0046] In some embodiments, the outer cage may be patterned to include a ring of eight support posts.

[0047] In some embodiments, the inner cage may be patterned to include a ring of four posts configured to hold a portion of the blood clot.

[0048] In some embodiments, the device may further include a first radiopaque marker at the distal end of the outer cage and a second radiopaque marker at the proximal end of the outer cage.

[0049] In some embodiments, the device may further include a clip, the clip having a c-shaped feature at each end of the clip, each feature configured to receive either a first elongated member or a second elongated member, and the clip is configured to connect the first elongated member and the second elongated member when attached.

[0050] In some embodiments, the device may further include a first elongated member attached to the proximal end of an outer cage, the first elongated member configured to move the outer cage between a delivery configuration and an expansion configuration, and a second elongated member attached to the proximal end of an inner cage, the second elongated member configured to move the inner cage between a delivery configuration and an expansion configuration.

[0051] In some embodiments, the second elongated member may be a wire.

[0052] In some embodiments, the first elongated member may be a tube.

[0053] In some embodiments, the first elongated member may comprise a first plurality of segments, each of which segments can decrease its outer diameter to form a taper, the first elongated member may have a variable stiffness profile along the first elongated member, and the proximal end of the first elongated member may be stiffer than the distal end of the first elongated member.

[0054] In some embodiments, the second elongated member may comprise a plurality of first segments, each of which segments can decrease its outer diameter to form a taper, the second elongated member may have a variable stiffness profile along the second elongated member, and the proximal end of the second elongated member may be stiffer than the distal end of the second elongated member.

[0055] In some embodiments, the device may further comprise the distal end of a second elongated member attached to the proximal end of the receptacle, the proximal end of the inner cage being attached within the cavity of the receptacle, and the second elongated member may be slidable within the lumen of the first elongated member.

[0056] In some embodiments, the receptacle may further include a step within the cavity to reduce the risk of overinsertion of the proximal end of the inner cage.

[0057] In some embodiments, the device may further include a predetermined pattern on the first elongated member in order to achieve a desired stiffness profile along the first elongated member.

[0058] In some embodiments, a given pattern may include one or more of the following: a helical pattern, one or more intermittent helical patterns, or one or more radial cut patterns.

[0059] In some examples, the first and second elongated members are located within the respective lumens of the first and second lubricating elongated member jackets within the microcatheter.

[0060] Other aspects and features of this disclosure will become apparent to those skilled in the art by considering the following detailed description in conjunction with the accompanying figures. [Brief explanation of the drawing]

[0061] The above and further aspects of this disclosure will be further considered in conjunction with the following description of the accompanying drawings, where similar figures in various drawings indicate similar structural elements and features. The drawings are not necessarily to scale, and instead, emphasis is placed on illustrating the principles of this disclosure. The figures depict one or more implementations of the device of the present invention, merely as examples and not as limitations. Those skilled in the art will anticipate that elements from multiple drawings can be conceived and combined to better suit the user's needs. [Figure 1A] An exemplary blood clot recovery device in an extended configuration was illustrated. [Figure 1B] An example cross-section of a receptacle is provided. [Figure 1C] This paper illustrates an exemplary blood clot retrieval device in a delivery configuration. [Figure 1D] An example plan view of a receptacle will be provided. [Figure 1E] An illustrative plan view of an exemplary blood clot retrieval device is provided. [Figure 1F] An example of a predetermined pattern arranged on an elongated member is illustrated. [Figure 1G] An example of a predetermined pattern arranged on an elongated member is illustrated. [Figure 1H]An example of a predetermined pattern arranged on an elongated member is illustrated. [Figure 1I] This example illustrates a blood clot retrieval device in a deployable configuration, positioned close to a blood clot within a blood vessel. [Figure 1J] This section illustrates an exemplary blood clot retrieval device that is positioned within a blood vessel and communicates with the blood clot. [Figure 1K] A cross-sectional diagram of an exemplary blood clot retrieval device is provided as an example. [Figure 2A] This paper illustrates an exemplary blood clot recovery device in an extended configuration. [Figure 2B] This paper illustrates an exemplary blood clot recovery device in an extended configuration. [Figure 2C] This paper illustrates an exemplary blood clot recovery device in an extended configuration. [Figure 2D] This paper illustrates an exemplary blood clot retrieval device in a delivery configuration. [Figure 2E] An exemplary cross-section of an exemplary blood clot retrieval device is illustrated. [Figure 2F] An exemplary cross-section of an exemplary blood clot retrieval device is illustrated. [Figure 2G] An exemplary cross-section of an exemplary blood clot retrieval device is illustrated. [Figure 2H] This example illustrates a blood clot retrieval device in a deployable configuration, positioned close to a blood clot within a blood vessel. [Figure 2I] This section illustrates an exemplary blood clot retrieval device that is positioned within a blood vessel and communicates with the blood clot. [Figure 2J] A cross-sectional diagram of an exemplary blood clot retrieval device is provided as an example. [Figure 2K] An exemplary clip from an exemplary blood clot recovery device is illustrated. [Figure 3] This is a flowchart illustrating the assembly of an exemplary blood clot recovery device. [Figure 4] This is a flowchart illustrating the operation of an exemplary blood clot retrieval device. [Modes for carrying out the invention]

[0062] Specific embodiments of this disclosure are described in detail herewith reference to the drawings, where the same reference numerals indicate functionally similar or identical elements. The embodiments address many of the shortcomings associated with conventional catheters, such as inefficient blood clot removal and inaccurate deployment of the catheter to the target site.

[0063] Accessing various vessels within the vascular system, whether coronary, pulmonary, or cerebral, involves well-known procedural steps and the use of many conventional commercially available accessory products. These products, such as angiographic materials and guidewires, are widely used in diagnostic and medical procedures. Where these products are used in conjunction with the systems and methods of this disclosure in the following description, their functions and exact configurations are not described in detail.

[0064] The following detailed descriptions are illustrative in nature and are not intended to limit the Disclosure or its applications and uses. While the descriptions in the Disclosure are often in connection with procedures on intracranial arteries, the Disclosure may also be used in other body passages as described above.

[0065] While specific embodiments of this disclosure have been illustrated and described, it will be apparent from the above description that various modifications can be made without departing from the spirit and scope of this disclosure. For example, while the embodiments described herein refer to specific features, this disclosure includes embodiments having different combinations of features. This disclosure also includes embodiments that do not include all of the specific features described. Specific embodiments of this disclosure are described herein in detail with reference to the drawings, and the same reference numerals indicate the same or functionally similar elements. The terms “distal” or “proximal” are used in the following description with respect to location or direction relative to the treating physician. “Distal” or “distal” means a location away from the physician or in a direction away from the physician. “Proximal” or “proximal” or “near” means a location close to the physician or in a direction toward the physician.

[0066] Accessing the cerebrum, coronary arteries, 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 this disclosure and do not necessarily need to be described in detail.

[0067] The following detailed descriptions are illustrative in nature and are not intended to limit the Disclosure or its applications and uses. While the descriptions in the Disclosure are often in connection with procedures on intracranial arteries, the Disclosure may also be used in other body passages as described above.

[0068] A common theme across many of the disclosed designs is a multilayer structure, in which the device may include an outer cage, which may sometimes include an inner cage, and both cages are directly or indirectly connected to one or more elongated members. Figure 1A shows an exemplary blood clot retrieval device 100 in an extended configuration including a first position. The device 100 may include an outer cage 102, an inner cage 108, a receptacle 116, a first elongated member 114, a second elongated member 118, and a microcatheter 120. The microcatheter 120 may include a lumen 122 with an inner diameter ID1, which may be about 0.021 inches. Alternatively, the inner diameter ID1 may be about 0.5 mm.

[0069] Additionally, device 100 may include a proximal radiopaque band 128a and / or a distal radiopaque band 128b. In an expanded configuration, the outer cage 102 can be expanded to an outer diameter OD1 and may be outside the lumen 122 of the microcatheter 120. The outer diameter OD1 may be about 0.6 mm, 2 mm, 4 mm, or 6.5 mm. Alternatively, the outer diameter OD1 may be about 0.6 mm to 6.5 mm. Alternatively, the outer diameter OD1 may be about 2 mm to 6.5 mm. Alternatively, the outer diameter OD1 may be proportional to the inner diameter ID1 of the microcatheter 120. In one embodiment, the outer diameter OD1 may be twice as large as the inner diameter ID1; for example, if the inner diameter ID1 is about 0.5 mm, the outer diameter OD1 will be about 1 mm. Thus, the outer diameter OD1 can be about 1, 4, 8, or 13 times larger than the inner diameter ID1. Alternatively, the outer diameter OD1 may be approximately 4 to 13 times larger than the inner diameter ID1. Additionally, in the expanded configuration, the inner cage 108 may be located outside the lumen 122 of the microcatheter 120.

[0070] The outer cage 102 may include a proximal end 104, a distal end 106, and an outer diameter OD1. The outer cage 102 can be fabricated from the network 103 of the outer struts. The proximal end 104 of the outer cage 102 may be configured to attach to the distal end 113a of the first elongated member 114. In the expanded configuration, the proximal end 104 of the outer cage 102 may be distal to the distal end 124 of the microcatheter 120. In the delivery configuration, as described in detail below, the distal end 106 of the outer cage 102 may be proximal to the distal end 124 of the microcatheter 120. The outer cage 102 can transition between the expanded and delivery configurations by sliding the lumen 122 of the microcatheter 120 proximal or distally over the outer cage 102, thereby expanding the outer cage 102 to an outer diameter OD1, and the inner cage similarly. Additionally or alternatively, the network of outer supports 103 of the outer cage 102 may include a predetermined pattern arranged thereon, including eight supports that are uniformly or non-uniformly distributed radially, forming a ring-shaped pattern, as will be discussed in detail below. However, more or fewer supports may be included as needed or required.

[0071] The outer cage 102 may preferably be made from a biocompatible material that can automatically recover its shape once released from a significantly distorted delivery configuration. For example, but not limited to, an outer cage 102 having an outer diameter OD1 of about 6.5 mm is radially crushed to be inserted into the lumen 122 of a microcatheter 120 having an inner diameter ID1 of about 0.5 mm, and the outer cage 102 undergoes about 92% compressive strain. In another embodiment, an outer cage 102 having an outer diameter OD1 of about 2 mm is radially crushed to be inserted into the lumen 122 of a microcatheter 120 having an inner diameter ID1 of about 0.5 mm, and the outer cage 102 undergoes about 75% compressive strain. Thus, when the term “significantly distorted delivery configuration” is used in this disclosure, it may refer to a location where the outer cage 102 undergoes about 75% to 92% compressive strain. However, other ranges corresponding to significantly distorted configurations are intended as needed or required.

[0072] In some embodiments, superelastic shape memory alloys such as nitinol, or biocompatible alloys with similar properties, may be particularly preferred. The material can be in many forms, such as wires, strips, sheets, or tubes. A particularly preferred manufacturing process is to laser-cut a nitinol tube, and then heat-treat and electropolish the resulting structure to create a network of support and connecting elements. This network can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements (e.g., platinum, tantalum, etc.) or through various other coatings or marker bands.

[0073] The inner cage 108 may include a proximal end 110, a distal end 112, and a network of inner struts 109. The inner cage 108 is substantially tubular and can be positioned concentrically within the outer cage 102 to form a flow channel 108a. The flow channel 108a may be configured to allow fluid flow between the proximal end 104 and the distal end 106 of the outer cage 102. Additionally or alternatively, the flow channel 108a may be configured to allow fluid flow between the proximal end 110 and the distal end 112 of the inner cage 108. Additionally or alternatively, the network of inner struts 109 of the inner cage 108 may include a predetermined pattern arranged thereon, including four struts that can be radially uniformly or non-uniformly distributed, forming a ring-shaped pattern, as will be discussed in detail below. However, more or fewer struts may be included as needed or required.

[0074] Two or more inner struts within a network of inner struts 109 communicating with each other directly or indirectly may be configured to form a clamping cell 109a (e.g., a cell). The network of inner struts 109 may be configured to tweeze a portion of a blood clot, as will be discussed in detail below. As discussed herein, the terms “tweeze” or “tweezing” are intended to refer to covering a clamping cell that tweezes or grasps at least a portion of a blood clot, with each strut together. In this regard, the number of struts in each cell does not need to be limited, but at least two strut surfaces must be included for tweezing the corresponding blood clot material. The inner cage 108 may preferably be made of a material that can automatically recover its shape when released from a significantly distorted delivery configuration. Superelastic shape memory alloys such as nitinol or alloys having similar properties may be particularly preferred. The material may be in many forms, such as wires or strips or sheets or tubes. A particularly preferred manufacturing process involves laser cutting a nitinol tube, followed by heat treatment and electropolishing of the resulting structure to create a network of support and connecting elements. This network can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements (e.g., platinum, tantalum, etc.) or through various other coatings or marker bands.

[0075] Referring to Figure 1B, the receptacle 116 may include a proximal end 116a with a mounting surface 116e, a cavity 116b with an opening 116d, and a step 116c located within the cavity 116b and having an inner diameter ID 3. The cavity 116b may be configured to receive the proximal end 110 of the inner cage 108. The proximal end 110 of the inner cage 108 can be attached to the cavity 116b of the receptacle 116. Alternatively, the proximal end 110 of the inner cage 108 may be attached to the step 116c of the receptacle 116. The proximal end 110 of the inner cage 108 may be attached using one or more welds. The step 116c can prevent over-insertion of the proximal end 110 of the inner cage 108. The receptacle may be substantially tubular, and 116 may be made of a shape memory alloy such as nitinol or another biocompatible metal. Additionally or alternatively, the mounting surface 116e may be configured to be attached to the distal end 119a of the second elongated member 118.

[0076] Returning to Figure 1A, the first elongated member 114 may include a distal end 113a, a proximal end 113b, and a lumen 115. The distal end 113a of the first elongated member 114 may be attached to the proximal end 104 of the outer cage 102 and may be configured to move the outer cage 102. The proximal end 104 of the outer cage 102 may be attached using one or more welds. The first elongated member 114 may be made of nitinol or another shape memory alloy. The first elongated member 114 may have one or more predetermined patterns, such as a helical pattern, one or more intermittent helical patterns, or one or more radial cut patterns, arranged on it to provide a variable stiffness profile along it, as will be considered below. Additionally or alternatively, the first elongated member 114 may be substantially tubular and may be configured to slide distally or proximal within the lumen 122 of the microcatheter 120. Additionally or alternatively, the first elongated member 114 may be configured to allow the second elongated member 118 and the receptacle 116 to slide distally or proximal within the lumen 115 of the first elongated member 114. Additionally or alternatively, the first elongated member 114 may include a taper to provide a variable stiffness profile along it, as will be discussed in detail below. The first elongated member 114 may preferably be made from a material that can automatically recover its shape when released from a significantly distorted delivery configuration. Superelastic shape memory alloys such as nitinol or alloys with similar properties may be particularly preferred. The material may be in many forms, such as wires or strips or sheets or tubes. A particularly preferred manufacturing process involves laser cutting a nitinol tube, followed by heat treatment and electropolishing of the resulting structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0077] The second elongated member 118 may include a distal end 119a and a proximal end 119b. The distal end 119b of the second elongated member 118 may be configured to attach to the proximal end 116a of the receptacle 116. Additionally or alternatively, the second elongated member can 118 is a wire. Additionally or alternatively, the second elongated member 118 may be a solid shaft and may be substantially cylindrical. Additionally or alternatively, the second elongated member 118 may be a hollow shaft including a lumen and may be substantially tubular. Additionally or alternatively, the second elongated member 118 may be made of nitinol or another shape memory alloy. Additionally or alternatively, the second elongated member 118 may include a taper along it to provide a variable stiffness profile, as will be discussed in detail below. The second elongated member 118 may have one or more predetermined patterns, such as a helical pattern, one or more intermittent helical patterns, or one or more radial cut patterns, arranged thereon to provide a variable stiffness profile, as will be discussed below.

[0078] Additionally or alternatively, the second elongated member 118 may be configured to slide distally or proximal within the lumen 115 of the first elongated member 114. This may be advantageous in eliminating the need to include a PEBAX jacket on the second elongated member 118 and in preventing damage to the blood vessel as a result of the “cheese wire” effect. Additionally or alternatively, the receptacle 116 may be configured to slide distally or proximal within the lumen 115. The second elongated member 118 can be attached to the receptacle 116 as considered above, and by sliding the second elongated member 118 proximal or distally, the receptacle 116 can be slid proximal or distal within the lumen 115 of the first elongated member 114. Additionally or alternatively, the movement of the second elongated member 118 in the distal or proximal direction can be controlled by attaching the proximal end 110 of the inner cage 108 to the receptacle 116, thereby transmitting the movement of the second elongated member 118 to the inner cage 108 via the receptacle 116, as discussed above, thus allowing the inner cage 108 to move in the distal and / or proximal directions. The second elongated member 118 can preferably be made from a material that can automatically recover its shape when released from a significantly distorted delivery configuration. Superelastic shape memory alloys such as nitinol or alloys having similar properties may be particularly suitable. The material can be in many forms, such as wires or strips or sheets or tubes. A particularly suitable manufacturing process is to laser cut a nitinol tube, and then heat-treat and electropolish the resulting structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0079] The microcatheter 120 may include a lumen 122 and a distal end 124. The inner diameter ID1 of the microcatheter 120 may be dimensioned to position at least a first elongated member 114 and an outer cage 102 slidably within the lumen 122. Furthermore, the inner cage 108 may be configured to slide within the lumen 122. The second elongated member 118 may be configured to slide within the lumen 122.

[0080] The proximal radiopaque band 128a can be located at the proximal end 104 of the outer cage 102. Additionally or alternatively, the proximal radiopaque band 128a can be located at the proximal end 110 of the inner cage 108. The proximal radiopaque band 128a can be composed of platinum or other radiopaque material. Preferably, the proximal radiopaque band 128a can be made from a material that can automatically recover its shape when released from a significantly distorted delivery structure. Superelastic shape memory alloys such as nitinol or alloys having similar properties may be particularly suitable. The material can be in many forms such as wires or strips or sheets or tubes. A particularly suitable manufacturing process is to laser cut a nitinol tube, and then heat treat and electropolish the resulting structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying materials or through various other coatings or marker bands.

[0081] The distal radiopaque band 128b can be located at the distal end 106 of the outer cage 102. Additionally or alternatively, the distal radiopaque band 128b can be located at the distal end 112 of the inner cage 108. The distal radiopaque band 128b can be composed of platinum or other radiopaque material. Preferably, the distal radiopaque band 128b can be made from a material that can automatically recover its shape when released from a significantly distorted delivery structure. Superelastic shape memory alloys such as nitinol or alloys having similar properties may be particularly suitable. The material can be in many forms, such as wires or strips or sheets or tubes. A particularly preferred manufacturing process is to laser cut a nitinol tube, and then heat-treat and electropolish the resulting structure to create the structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0082] Figure 1C shows device 100 in a delivery configuration including a second position. In the delivery configuration, device 100 may be outside the patient ready for delivery, and the outer cage 102 may be within the lumen 122 of the microcatheter 120, and may have a diameter substantially similar to the inner diameter ID1 of the microcatheter 120. Alternatively, in the delivery configuration, at least a portion of device 100 may be within the patient's blood vessel. Furthermore, in the delivery configuration, the distal end 106 of the outer cage 102 and the distal end 112 of the inner cage 108 may be within the lumen 122 of the microcatheter 120, which has an inner diameter ID1. The inner diameter ID1 of the microcatheter 120 may be less than the outer diameter OD1 of the outer cage 102 in the expanded configuration. Furthermore, the distal radiopaque band 128b may be within the lumen 122.

[0083] Figure 1D shows a front cross-sectional view of the blood clot recovery device 100. This figure shows various embodiments of the receptacle 116 in detail. The receptacle 116 may include an opening 116d with an inner diameter ID3. The receptacle 116 may include a cavity 116b with an inner diameter ID3 in at least a portion of the cavity 116b. The receptacle 116 may be positioned within the lumen 115 of the first elongated member 114. The first elongated member 114 may include a dimension larger than the inner diameter ID3 of the opening 116d but smaller than the inner diameter ID1 of the microcatheter 120, with an inner diameter ID2. Step 116c may be positioned within the cavity 116b of the receptacle 116. To prevent over-insertion of the proximal end 110 of the inner cage 108, step 116c reduces the inner diameter ID3 of the cavity 116b to inner diameter ID4, thereby preventing the proximal end 110 of the inner cage 108 from being welded to the proximal end 116a of the receptacle 116. The proximal end 110 of the inner cage 108 can be attached to the cavity 116b of the receptacle 116. Alternatively, the proximal end 110 of the inner cage 108 can be attached to step 116c of the receptacle 116. The proximal end 110 of the inner cage 108 can be attached using one or more welds.

[0084] Figure 1E shows a cross-section of the outer cage 102, which includes an outer support network 103, and the inner cage 108, which includes an inner support network 109, while in the delivery position. Additionally or alternatively, the outer support network 103 can be patterned to include 6 to 10 supports that can be uniformly or non-uniformly distributed around the centerline of the outer cage 102. Additionally or alternatively, the inner support network 109 can be patterned to include 2 to 6 supports that can be uniformly or non-uniformly distributed around the centerline of the inner cage 108.

[0085] Figures 1F to 1H show examples of predetermined patterns placed on the first elongated member 114. Figure 1F shows the first elongated member 114 including a helical cut 126a placed thereon. The helical cut 126a may be a helix having a uniform helical angle that forms a uniform spacing between each rotation of the helix and / or a uniform spacing between each rotation of the helix along the length of the first elongated member 114. Alternatively, the helical cut 126a may be a helix having a non-uniform spacing between each rotation of the helix and / or a non-uniform helical angle that forms a non-uniform spacing between each rotation of the helix along the length of the first elongated member 114, thereby creating variable stiffness of the first elongated member 114 along its length. Furthermore, the second elongated member 118 may include helical cuts such as the helical cut 126a placed thereon. Figure 1G shows a first elongated member 114 including an intermittent helical pattern 126b positioned thereon. The intermittent helical pattern 126b may be a helical cut having uniform spacing between each rotation of the helix and / or uniform helical angles that form uniform spacing between each rotation of the helix along the length of the first elongated member 114. Alternatively, the intermittent helical pattern 126b may be a helical cut that includes non-uniform spacing between each rotation of the helix and / or non-uniform helical angles that form non-uniform spacing between each rotation of the helix along the length of the first elongated member 114, thereby resulting in variable stiffness of the first elongated member 114 along its length. Furthermore, the second elongated member 118 may include an intermittent helical pattern, such as the intermittent helical pattern 126b positioned thereon. The spiral (or spiral-shaped) cut does not have to be continuous; in other words, there may be multiple cuts interrupted or separated by the material of the first elongated member 114. Figure 1H shows the first elongated member 114 with a radial cut pattern placed thereon. The radial pattern 126c may be multiple cuts perpendicular to the length of the first elongated member 114 and uniformly repeated along the length of the first elongated member 114. Alternatively, the radial pattern 126c may be multiple cuts perpendicular to the length of the first member 114 and non-uniformly repeated along the length of the first elongated member 114.Furthermore, the second elongated member 118 may include a radial pattern, such as the radial pattern 126c, placed on it.

[0086] Figure 1I illustrates an exemplary blood clot retrieval device 100 in a deployed configuration, including a third location within a blood vessel 2 and communicating with the blood clot 1. Additionally, in the deployed configuration, the outer cage 102 may be located outside (e.g., distally) the lumen 122 of the microcatheter 120. Additionally, in the deployed configuration, the inner cage 108 may be located outside (e.g., distally) the lumen 122 of the microcatheter 120. The inner cage 108 and outer cage 102 can be deployed by retracting the microcatheter 120 in the proximal direction. As a result, a portion of the blood clot 1 can communicate with the outer cage 102 and / or the inner cage 108. Specifically, a portion of the blood clot 1 can communicate with the network of inner struts 109 and / or the network of outer struts 103. The flow path 108a of the inner cage 108 can allow fluid to flow beyond the blood clot 1. The first elongated member 114 and the second elongated member 118 can move independently of each other in the proximal and / or distal directions. Additionally or alternatively, the first elongated member 114 and the second elongated member 118 can be joined at their respective proximal ends 113b, 119b so that they move together in the proximal and / or distal directions.

[0087] Figure 1J illustrates an exemplary blood clot retrieval device 100 in a clamping configuration within a blood vessel 2 and communicating with a blood clot 1. Additionally, in the clamping configuration, a portion of the outer cage 102 may be outside the lumen 122 of the microcatheter 120 and may communicate with a portion of the blood clot 1. Furthermore, in the clamping configuration, a portion of the inner cage 108 may be outside the lumen 122 of the microcatheter 120 and may clamp or grasp a portion of the blood clot 1. The first elongated member 114 and the second elongated member 118 can move independently of each other in the proximal and / or distal directions. Additionally or alternatively, the first elongated member 114 and the second elongated member 118 may be disconnected at their respective proximal ends 113b, 119b so that they can move independently. The microcatheter 120 and / or the first elongated member 114 can advance over (e.g., re-cover) the second elongated member 118. Additionally or alternatively, the microcatheter 120 and / or the first elongated member 114 can advance over the inner cage 108 so that the network of inner struts 109 configured to form pinch cells 109a can grasp a portion of the blood clot 1. It may be advantageous for the first elongated member 114 and the second elongated member 118 to move independently, since the network of outer struts 103 may remain in communication with and / or engaged with the portion of the blood clot 1 while the pinching cells 109a of the inner cage 108 can grasp a portion of the blood clot 1.

[0088] Figure 1K shows an exemplary first elongated member 114 and an exemplary second elongated member 118, which include a taper. The first elongated member 114 may include a plurality of first segments 114a, 114b, each of which may include increasing outer diameters OD5 and OD6, respectively, so that a taper can be formed. Additionally or alternatively, an increase in the corresponding inner diameter of the first segments 114a, 114b is intended. For example, the outer diameter OD6 of segment 114b may be greater than the outer diameter OD5 of segment 114a, and the inner diameter associated with segment 114b may be greater than the inner diameter associated with segment 114a. The taper may be continuous and may include, for example, an outer diameter at the proximal end 113b of the first elongated member 114 and a smaller outer diameter at the distal end 113a of the first elongated member 114. Additionally or alternatively, a continuous taper of the corresponding inner diameter is also conceivable. As an example, the continuous taper of the corresponding inner diameter may include an inner diameter at the proximal end 113b of the first elongated member 114 and a smaller inner diameter at the distal end 113a of the first elongated member 114. The first elongated member 114 may include a variable stiffness profile along it, with the proximal end 113b being stiffer than the distal end 113a of the first elongated member 114. The second elongated member 118 may include the first plurality of segments 118a, 118b, and 118c, each of which may include increasing outer diameters OD2, OD3, and OD4, so that a taper can be formed. The taper may be continuous and may include, for example, an outer diameter at the proximal end 119b of the second shaft 118 and a smaller outer diameter at the distal end 119a of the second shaft 118. The second elongated member 118 may have a variable stiffness profile along it, with the proximal end 113b of the first elongated member 114 being stiffer than the distal end 113a of the first elongated member 114. Additionally or alternatively, only the second elongated member 118 may include a taper. Additionally or alternatively, only the first elongated member 114 may include a taper. In the embodiment, both the first elongated member 114 and the second elongated member 118 include a taper.

[0089] Figures 2A–2C illustrate an exemplary blood clot retrieval device 200 in an extended configuration including a first position, the configuration of which has been previously described. The device 200 may include an outer cage 202, an inner cage 208, a first elongated member 220, a second elongated member 216, a first lubrication jacket 221, a second lubrication jacket 217, and a microcatheter 120. Additionally, the device 200 may include a proximal radiopaque band 134a and / or a distal radiopaque band 134b.

[0090] The outer cage 202 may include a proximal end 204, a distal end 206, and an outer diameter OD1. The outer cage 202 can be fabricated from a network of outer struts 203. The proximal end 204 of the outer cage 202 may be configured to attach to the distal end 218 of the first elongated member 220. In the expanded configuration, the proximal end 204 of the outer cage 202 may be distal to the distal end 124 of the microcatheter 120, thereby expanding the outer cage 202 to an outer diameter OD1, and similarly expanding the inner cage 208. In the delivery configuration, as described in detail below, the distal end 206 of the outer cage 202 may be proximal to the distal end 124 of the microcatheter 120. The outer cage 202 can transition between the deployed configuration and the delivery configuration by sliding the lumen 122 of the microcatheter 120 proximal or distally over the outer cage 202. Additionally or alternatively, the network of outer struts 203 of the outer cage 202 may include a predetermined pattern arranged thereon, including eight struts uniformly or non-uniformly distributed, forming a ring-shaped pattern in the radial direction, as will be discussed in detail below. However, more or fewer struts may be included as needed or required. Referring to Figures 2B and 2C, a C-shaped collar 232 may be positioned at the proximal end 204 of the outer cage 202. The C-shaped collar 232 may include a lumen 232a configured to receive and communicate with a positioning pin 226 at the distal end 218 of the first elongated member 220. Furthermore, the C-shaped collar 232 may communicate with the network of outer struts 203. Furthermore, the C-shaped collar 232 may abut against a step 222 of the first elongated member 220, thereby causing the outer cage 202 to move distally by sliding the first elongated member distally. Furthermore, by sliding the first elongated member 220 in the proximal direction, the step 222 is disengaged from the C-shaped collar 232, and the positioning pin 226 is slid out of the lumen 232a of the C-shaped collar 232, preventing the outer cage 202 from moving in the proximal direction.

[0091] Referring back to Figure 2A, the outer cage 202 can preferably be made from a material that can automatically recover its shape once released from a significantly strained delivery configuration. Superelastic shape memory alloys such as nitinol, or biocompatible metal alloys with similar properties, may be particularly suitable. The material can be in many forms, such as wires, strips, sheets, or tubes. A particularly suitable manufacturing process is to laser-cut a nitinol tube, and then heat-treat and electropolish the resulting structure to create a network of support and connecting elements. This network can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0092] The inner cage 208 may include a proximal end 210, a distal end 212, and a network of inner struts 209. The inner cage 208 is substantially tubular and can be positioned concentrically within the outer cage 202 to form a flow channel 208a. The flow channel 208a may be configured to allow fluid flow between the proximal end 204 and the distal end 206 of the outer cage 202. Additionally or alternatively, the flow channel 208a may be configured to allow fluid flow between the proximal end 210 and the distal end 212 of the inner cage 208. Additionally or alternatively, the network of inner struts 209 of the inner cage 208 may include a predetermined pattern arranged thereon, including four struts that can be radially uniformly or non-uniformly distributed, forming a ring-shaped pattern, as will be discussed in detail below. However, more or fewer struts may be included as needed or required. Referring to Figures 2B and 2C, a C-shaped collar 230 may be positioned at the proximal end 210 of the inner cage 208. The C-shaped collar 230 can be attached to the guide pin 228 at the distal end 214 of the second elongated member 216. Furthermore, the C-shaped collar 230 can communicate with the network 209 of the inner support. Additionally or alternatively, the C-shaped collar 232 can abut against the step 224 of the second elongated member 216, thereby causing the inner cage 208 to move in the respective direction by sliding the second elongated member distally or proximally. The C-shaped collar 230 can be welded to the guide pin 228. Additionally or alternatively, the C-shaped collar can be welded to the step 224.

[0093] Referring back to Figure 2A, two or more struts within the inner strut network 209 can communicate directly or indirectly with each other and be configured to form a clamping cell 209a (e.g., a cell). The inner strut network 209 can be configured to tweeze a portion of a blood clot, as will be discussed in detail below. As discussed herein, the terms “tweeze” or “tweezing” are intended to refer to covering a clamping cell that tweezes or grasps at least a portion of a blood clot, with each strut together. In this regard, the number of struts in each cell does not need to be limited, but at least two strut surfaces must be included for tweezing the corresponding blood clot material. The inner cage 208 can preferably be made from a material that can automatically recover its shape when released from a significantly distorted delivery configuration. Superelastic shape memory alloys such as nitinol or alloys with similar properties are particularly preferred. The material can be in many forms, such as wires or strips or sheets or tubes. A particularly preferred manufacturing process involves laser cutting a nitinol tube, followed by heat treatment and electropolishing of the resulting structure to produce a framework of struts and connecting elements. This framework can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0094] Referring to Figures 2B and 2C, the first elongated member 220 may include a distal end 218 and a proximal end 219. Additionally, at the distal end 218, the first elongated member 220 may include a step 222 configured to abut against the c-shaped collar 232 of the outer cage 202. Furthermore, a positioning pin 226 located distal to the step 222 may be configured to be inserted into the lumen 232a of the c-shaped collar 232 of the outer cage 202. Referring back to Figure 2A, the proximal end 218 of the first elongated member 220 may be configured to receive a clip configured to connect the first elongated member 220 to the second elongated member 216, so that, as will be discussed below, the other elongated member slides as a result of the first elongated member 220 or the second elongated member 216 sliding proximal or distally. Additionally or alternatively, the first elongated member 220 may include one or more predetermined patterns, such as a helical pattern (e.g., helical cut 126a), one or more intermittent helical patterns (e.g., intermittent helical pattern 126b), or one or more radial cut patterns (e.g., radial pattern 126c), arranged thereon to provide a variable stiffness profile along it, as discussed below. Additionally or alternatively, the first elongated member 220 may be a wire, shaft, or tube and may be configured to slide distally or proximal within the lumen 122 of the microcatheter 120. Preferably, the first elongated member 220 may be made from a material that can automatically recover its shape when released from a significantly distorted delivery configuration. Superelastic shape memory alloys such as nitinol or biocompatible alloys having similar properties are particularly preferred. The material may be in many forms, such as a wire or strip or a sheet or a tube. A particularly preferred manufacturing process involves laser cutting a nitinol tube, followed by heat treatment and electropolishing of the resulting structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements (e.g., platinum) or through various other coatings or marker bands.

[0095] The first lubrication jacket 221 may include a lumen 221a. The first elongated member 220 may be configured to slide proximal or distally within the lumen 221a of the first lubrication jacket 221. The lubrication provided by the first lubrication jacket 221 may be advantageous in reducing friction between the first elongated member 220 and, for example, the lumen 221a of the first lubrication jacket 221. Additionally or alternatively, the first lubrication jacket 221 may isolate at least a portion of the first elongated member 220 from friction with the lumen 122 and / or the second lubrication jacket 217 of the microcatheter 120. The lubricant may be an elastomer such as PEBAX and / or other suitable lubricants. The first elongated member 220 and the first lubrication jacket 221 may include substantially circular or elliptical cross-sections. Alternatively, the first elongated member 220 and the first lubrication jacket 221 may include substantially asymmetrical cross-sections. Furthermore, the first elongated member 220 can be positioned concentrically within the lumen 221a of the first lubrication jacket 221.

[0096] Referring back to Figures 2B and 2C, the second elongated member 216 may include a distal end 214 and a proximal end 215. Additionally, at the distal end 214, the second elongated member 216 may include a step 224 configured to attach to a C-shaped collar 230 of the inner cage 208. Furthermore, a guide pin 228 located distal to the step 224 may be configured to attach to the C-shaped collar 230 of the inner cage 208. Referring back to Figure 2A, the proximal end 215 of the second elongated member 216 may be configured to receive a clip configured to connect the second elongated member 216 to the first elongated member 220, so that, as will be discussed below, the other elongated member slides as a result of the second elongated member 216 or the first elongated member 220 sliding proximal or distally.

[0097] Additionally or alternatively, the second elongated member 216 may include one or more predetermined patterns arranged thereon to provide a variable stiffness profile along it, as discussed below, such as a helical pattern (e.g., helical cut 126a), one or more intermittent helical patterns (e.g., intermittent helical pattern 126b), or one or more radial cut patterns (e.g., radial pattern 126c). Additionally or alternatively, the second elongated member 216 may be a wire, shaft, or tube and may be configured to slide distally or proximal within the lumen 122 of the microcatheter 120. Preferably, the second elongated member 216 may be made from a material that can automatically recover its shape when released from a significantly distorted delivery configuration. Superelastic shape memory alloys such as nitinol or biocompatible metal alloys having similar properties are particularly preferred. The material may be in many forms, such as a wire or strip or a sheet or a tube. A particularly preferred manufacturing process may involve laser cutting of the nitinol tube, followed by heat treatment and electropolishing of the resulting structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0098] The second lubrication jacket 217 may include a lumen 217a. The second elongated member 216 may be configured to be on the proximal or distal side within the lumen 217a of the second lubrication jacket 217. The lubrication provided by the second lubrication jacket 217 may be advantageous in reducing friction between the second elongated member 216 and, for example, the lumen 217a of the second lubrication jacket 217. Additionally or alternatively, the second lubrication jacket 217 may isolate at least a portion of the second elongated member 216 from friction with the lumen 122 and / or the first lubrication jacket 221 of the microcatheter 120. The lubricant may be an elastomer such as PEBAX and / or other suitable lubricants. The second elongated member 216 and the second lubrication jacket 217 may include substantially circular or elliptical cross-sections. Alternatively, the second elongated member 216 and the second lubrication jacket 217 may include substantially asymmetrical cross-sections. Furthermore, the second elongated member 216 can be positioned concentrically within the lumen 217a of the second lubrication jacket 217.

[0099] The proximal radiopaque band 234a can be located at the proximal end 204 of the outer cage 202. Additionally or alternatively, the proximal radiopaque band 234a can be located at the proximal end 210 of the inner cage 208. The proximal radiopaque band 234a can be composed of platinum or other radiopaque material. Preferably, the proximal radiopaque band 234a can be made from a material that can automatically recover its shape when released from a significantly distorted delivery structure. Superelastic shape memory alloys such as nitinol or alloys having similar properties may be particularly suitable. The material can be in many forms such as wires or strips or sheets or tubes. A particularly suitable manufacturing process is to laser cut a nitinol tube, and then heat-treat and electropolish the resulting structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0100] The distal radiopaque band 234b can be located at the distal end 206 of the outer cage 202. Additionally or alternatively, the distal radiopaque band 234b can be located at the distal end 212 of the inner cage 208. The distal radiopaque band 234b can be composed of platinum or other radiopaque material. Preferably, the distal radiopaque band 234b can be made from a material that can automatically recover its shape when released from a significantly distorted delivery structure. Superelastic shape memory alloys such as nitinol or alloys having similar properties may be particularly suitable. The material can be in many forms, such as wires or strips or sheets or tubes. A particularly suitable manufacturing process is to laser cut a nitinol tube, and then heat-treat and electropolish the resulting structure. This structure can be in any of the wide variety of shapes disclosed herein and can be visualized under fluorescence fluoroscopy through the addition of alloying elements or through various other coatings or marker bands.

[0101] Figure 2D illustrates device 200 in a delivery configuration in a second position, as its configuration has been previously described. The distal end 206 of the outer cage 202 and the distal end 212 of the inner cage 208 are close to the distal end 124 of the microcatheter 120 and may be within the lumen 122 of the microcatheter 120, including the inner diameter ID1. Furthermore, the distal radiopaque band 128b may be within the lumen 122. The inner diameter ID1 of the microcatheter 120 may be less than the outer diameter OD1 of the outer cage 202 in the expanded configuration. In the delivery configuration, the distal end 206 of the outer cage 202 may be proximal to the distal end 124 of the microcatheter 120. The outer cage 202 can transition between the expanded configuration and the delivery configuration by sliding the lumen 122 of the microcatheter 120 proximal or distally over the outer cage 202.

[0102] Figure 2E shows a cross-section of the outer cage 202, which includes an outer support network 203, and the inner cage 208, which includes an inner support network 209, while in the delivery position. Additionally or alternatively, the outer support network 203 can be patterned to include 6 to 10 supports uniformly or unevenly distributed around the centerline of the outer cage 202. Additionally or alternatively, the inner support network 209 can be patterned to include 2 to 6 supports that can be uniformly or unevenly distributed around the centerline of the inner cage 208.

[0103] Figures 2F to 2G illustrate exemplary cross-sections of an exemplary blood clot recovery device. Figure 2F illustrates exemplary configurations of a first elongated member 220 and a second elongated member 216 within the lumen 122 of a microcatheter 120. The first elongated member 220 and the second elongated member 216 may include substantially circular and / or elliptical cross-sections. The first lubrication jacket 221 and the second lubrication jacket 217 may include substantially circular and / or elliptical cross-sections corresponding to the cross-sections of their respective elongated members. The first elongated member 220 and the second elongated member 216 may be concentrically positioned within the first lubrication jacket 221 and the second lubrication jacket 217, respectively. Figure 2G illustrates exemplary configurations of a first elongated member 220 and a second elongated member 216 within the lumen 122 of a microcatheter 120. The first elongated member 220 and the second elongated member 216 may include substantially horseshoe-shaped and / or elliptical cross-sections. The first lubrication jacket 221 and the second lubrication jacket 217 may include substantially horseshoe-shaped and / or elliptical cross-sections corresponding to the cross-sections of the respective elongated members. The first elongated member 220 and the second elongated member 216 may be positioned concentrically within the first lubrication jacket 221 and the second lubrication jacket 217, respectively.

[0104] Figure 2H illustrates an exemplary blood clot retrieval device 200 in a deployed configuration, located at a third position within a blood vessel 2 and communicating with the blood clot 1, as its configuration has been previously described. Retraction of the microcatheter 120 in the proximal direction allows the inner cage 208 and outer cage 202 to be deployed. As a result, a portion of the blood clot 1 can communicate with the outer cage 202 and / or the inner cage 208. Specifically, a portion of the blood clot 1 can communicate with the network of inner struts 209 and / or the network of outer struts 203. The flow path 208a of the inner cage 208 can allow fluid to flow over the blood clot 1. Additionally or alternatively, the first elongated member 220 and the second elongated member 216 may be joined at their respective proximal ends 219, 215 so that they move independently. As will be discussed below, the clip 235 can be used to connect or disconnect the first elongated member 220 and the second elongated member 216. Alternatively, the clip 235 can be removed to disconnect the first elongated member 220 and the second elongated member 216, allowing them to move independently of each other in the proximal and / or distal directions.

[0105] Figure 2I illustrates an exemplary blood clot retrieval device 200 that is in a pinching configuration within a blood vessel 2 and communicates with a blood clot 1. Additionally or alternatively, the first elongated member 220 and the second elongated member 216 can be detached at their respective proximal ends 219, 215 so that they move independently. Additionally or alternatively, the microcatheter 120 can be advanced (e.g., re-covered) over the second elongated member 216 and / or the inner cage 208 so that a network of inner supports 209 configured to form a pinch cell 209a can pinch a portion of the blood clot 1. Since the clamping cells 209a of the inner cage 208 can clamp a portion of the blood clot 1, the network 203 of the outer support may remain in communication with and / or engaged with the portion of the blood clot 1, it may be advantageous for the first elongated member 220 and the second elongated member 216 to move independently.

[0106] Figure 2J shows an exemplary first elongated member 220 and an exemplary second elongated member 216, including a taper. The first elongated member 220 may include a plurality of first segments 220a, 220b, 220c, each of which may include increasing outer diameters OD9, OD8, ​​and OD7, and thus may include a plurality of first segments 114a, 114b, such that a taper can be formed. The taper may be, for example, continuous and may include an outer diameter at the proximal end 219 of the first elongated member 220 and a smaller outer diameter at the distal end 218 of the first elongated member 220. The first elongated member 220 may include a variable stiffness profile along it, with the proximal end 219 being stiffer than the distal end 219 of the first elongated member 220. The second elongated member 216 may include the first plurality of segments 216a, 216b, and 216c, each of which may include increasing outer diameters OD12, OD11, and OD10, so that a taper can be formed. The taper may be continuous and may include, for example, an outer diameter at the proximal end 215 of the second shaft 216 and a smaller outer diameter at the distal end 214 of the second shaft 216. The second elongated member 216 may include a variable stiffness profile along it, with the proximal end 215 being stiffer than the distal end 214. Additionally or alternatively, only the second elongated member 216 may include a taper. Additionally or alternatively, only the first elongated member 220 may include a taper. In this embodiment, the first elongated member 220 and the second elongated member 216 include a taper.

[0107] In some embodiments, the first lubrication jacket 221 and the second lubrication jacket 217 may include a plurality of segments, each having a corresponding inner diameter that is substantially equal in dimensions to the outer diameter of each corresponding segment of the respective elongated member, thereby forming a taper in the lumen of each respective lubrication jacket. In one embodiment, the lumen 221a of the first lubrication jacket 221 may include a plurality of segments, each having a certain inner diameter. The first segment of the first lubrication jacket 221 may correspond to the first segment of the first elongated member 220, for example, the first segment 220a, so that the inner diameter of the first segment of the first lubrication jacket 221 may be substantially equal to the outer diameter OD9. Alternatively, the first and second lubrication jackets may each have a constant inner diameter. Additionally or alternatively, the constant inner diameter of the first lubrication jacket 221 may be the same as the constant inner diameter of the second lubrication jacket 217. Additionally or alternatively, a certain inner diameter of the first lubrication jacket 221 may differ from a certain inner diameter of the second lubrication jacket 217.

[0108] Figure 2K illustrates an exemplary clip 235 of an exemplary blood clot recovery device 200. The clip 235 may include a first C-shaped feature 236 and a second C-shaped feature 238 having a connecting structure 239 between them. The first C-clip 236 and the second C-clip 238 may be configured to receive a first elongated member 220 and / or a second elongated member 216. Furthermore, the first C-shaped feature 236 and the second C-shaped feature 238 may be configured to receive the proximal ends 219, 215 of the first elongated member 220 and / or the second elongated member 216. The C-shaped feature 236, 238 may be made from stainless steel, plastic, and / or other suitable materials. The clip 235 can be configured to connect the first elongated member 220 and the second elongated member 216 when it engages with the first C-shaped feature portion 236 and the second C-shaped feature portion 238. The clip 235 can also be configured to disconnect the first elongated member 220 and the second elongated member 216 when it is disengaged from the first C-shaped feature portion 236 and the second C-shaped feature portion 238.

[0109] Figure 3 is a flowchart illustrating a method (300) for assembling an exemplary blood clot recovery device. Method 300 may include, in block 302, patterning a first predetermined pattern on a first tube to form an outer cage (e.g., outer cage 102), the outer cage including an outer diameter (e.g., outer diameter OD1). In block 304, Method 300 may include patterning a second predetermined pattern on a second tube to form an inner cage (e.g., inner cage 108) having an inner channel (e.g., channel 108a), and in block 304, it may include positioning the inner cage concentrically within the outer cage. Additionally or alternatively, the blood clot recovery device (e.g., blood clot recovery device 100) may include an expansion configuration in which the outer diameter of the microcatheter (e.g., microcatheter 120) is larger than the inner diameter (e.g., inner diameter ID1).

[0110] Additionally or alternatively, the outer diameter of the first tube can be approximately equal to the outer diameter of the blood clot recovery device in the expanded configuration, thereby allowing the outer cage to expand to a larger diameter under the blood clot (e.g., blood clot 1) or improving the juxtaposition of the blood vessel wall (e.g., blood vessel 2) when both the blood clot recovery device and the outer cage have equal radial forces, compared to an outer cage with a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device.

[0111] Additionally or alternatively, the outer diameter of the first tube can be larger than the outer diameter of the blood clot recovery device in the expanded configuration, thereby allowing the outer cage to expand to a larger diameter below the blood clot or improving juxtaposition with the vessel wall, when compared to an outer cage of a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device, provided that both the blood clot recovery device and the outer cage have equal radial forces.

[0112] Additionally or alternatively, the network of outer posts 103 of the outer cage 102 may include a predetermined pattern arranged thereon, including eight posts uniformly or non-uniformly distributed to form a ring-shaped pattern in the radial direction, as will be discussed in detail below. However, more or fewer posts may be included as needed or required. Additionally or alternatively, the network of inner posts 109 of the inner cage 108 may include a predetermined pattern arranged thereon, including four posts that can be uniformly or non-uniformly distributed in the radial direction to form a ring-shaped pattern, as will be discussed in detail below. However, more or fewer posts may be included as needed or required.

[0113] Additionally or alternatively, Method 300 may include attaching a first radiopaque marker (e.g., distal radiopaque band 128b) to the distal end of the outer cage (e.g., distal end 106). Additionally or alternatively, Method 300 may include attaching a second radiopaque marker (e.g., proximal radiopaque marker 128a) to the proximal end of the outer cage (e.g., proximal end 104).

[0114] Additionally or alternatively, Method 300 may include attaching a first elongated member (e.g., a first elongated member 114) to the proximal end of the outer cage. The first elongated member may be configured to move the outer cage between a delivery configuration and an expansion configuration. Additionally or alternatively, Method 300 may include attaching a second elongated member (e.g., a second elongated member 118) to the proximal end of the inner cage. The second elongated member may be configured to move the inner cage between a delivery configuration and an expansion configuration. Additionally or alternatively, the first elongated member may be a tube. Additionally or alternatively, the second elongated member may be a wire.

[0115] Additionally or alternatively, the second elongated member may be a plurality of segments of the first (e.g., a plurality of first segments 114a, 114b), where each of the plurality of segments may include an increasing outer diameter (e.g., OD5, OD6), thereby allowing a taper to be formed. Additionally or alternatively, the second elongated member may include a variable stiffness profile along it, where the proximal end of the second elongated member 216 (e.g., proximal end 113b) is stiffer than the distal end of the second elongated member (e.g., distal end 119a). Additionally or alternatively, the first and second elongated members may be located in separate lumens within the microcatheter.

[0116] Additionally or alternatively, Method 300 may include attaching the distal end (e.g., 119a) of a second elongated member to the proximal end (e.g., proximal end 116a) of a receptacle (e.g., receptacle 116). Additionally or alternatively, Method 300 may include attaching the proximal end (e.g., proximal end 110) of an inner cage to a cavity (e.g., cavity 116b) of the receptacle. Additionally or alternatively, the second elongated member may be slidable within the lumen (e.g., lumen 115) of the first elongated member. Additionally or alternatively, the receptacle may include a step (e.g., step 116c) within the cavity to prevent the proximal end of the inner cage from being overinserted.

[0117] Additionally or alternatively, Method 300 may include patterning a third predetermined pattern on the first elongated member in order to achieve a desired stiffness profile along the first elongated member. Additionally or alternatively, the third predetermined pattern may include one or more of the following: a helical pattern (e.g., helical pattern 126a), one or more intermittent helical patterns (e.g., intermittent helical pattern 126b), or one or more radial cut patterns (e.g., radial cut pattern 126c).

[0118] Additionally or alternatively, method 300 may include decoupling the first and second elongated members (e.g., the first and second elongated members 216 and 220), causing the cells of the inner cage (e.g., the clamping cells 209a) to collapse over the blood clot and apply additional pressure to the portion of the clot, or advancing the microcatheter proximal over the inner cage by engaging the blood clot between the distal end of the microcatheter and the cells of the inner cage.

[0119] Additionally or alternatively, Method 300 may further include using a clip (e.g., clip 235) including a C-shaped feature (e.g., a first C-shaped feature 236 and a second C-shaped feature 238) to attach the proximal ends (e.g., proximal ends 215, 219) of the first elongated member and the second elongated member, respectively, using the C-shaped feature, and joining the first elongated member and the second elongated member (e.g., the first elongated member 216 and the second elongated member 220) by sliding them simultaneously in the distal or proximal direction.

[0120] Figure 4 is a flowchart illustrating the operation of an exemplary blood clot retrieval device. Method 400 may include, in block 402, positioning a microcatheter (e.g., microcatheter 120) in close proximity to a blood clot (e.g., blood clot 1) within a blood vessel (e.g., blood vessel 2). In block 404, Method 400 may include retracting the microcatheter proximal so that the outer cage (e.g., outer cage 102) and inner cage (e.g., inner cage 108) within the lumen of the microcatheter (e.g., lumen 122) expand around the blood vessel wall and engage with a portion of the blood clot. In block 406, method 400 may include retracting a first elongated member communicating with the inner cage (e.g., a second elongated member 118) or a second elongated member communicating with the outer cage (e.g., a first elongated member 114) proximal to reduce the distance between adjacent struts of the inner cage (e.g., the inner strut network 209) or struts of the outer cage (e.g., the outer strut network 103) to apply pressure to the portion of the blood clot engaged with the inner or outer strut, thereby clamping the blood clot. In block 408, method 400 may include advancing the microcatheter distally over one of the first or second elongated members. Additionally or alternatively, a portion of the blood clot is grasped by advancing the microcatheter by causing the cells of the inner cage (e.g., clamping cells 109a) to collapse on the blood clot, thereby applying additional pressure to the portion of the clot, or by engaging the blood clot between the distal end of the microcatheter and the cells of the inner cage.

[0121] Additionally or alternatively, Method 400 may include joining the first elongated member and the second elongated member by using a clip (e.g., clip 235) that includes a C-shaped feature (e.g., a first C-shaped feature 236 and a second C-shaped feature 238) to attach the proximal ends of the first elongated member and the second elongated member, respectively, using the C-shaped feature. Additionally, the first elongated member and the second elongated member may be simultaneously slid distally or proximal.

[0122] Additionally or alternatively, method 400 may include a microcatheter, a first elongated member and a second elongated member, an inner cage and an outer cage, and a mechanism for retracting a blood clot from the vessel wall. Additionally or alternatively, the network of outer struts 103 of the outer cage 102 may include a predetermined pattern arranged thereon, including eight uniformly distributed struts that form a ring-shaped pattern in the radial direction, as will be discussed in detail below. However, more or fewer struts may be included as needed or required. Additionally or alternatively, the network of outer struts 109 of the inner cage 108 may include a predetermined pattern arranged thereon, including four struts that can be uniformly or non-uniformly distributed in the radial direction that form a ring-shaped pattern, as will be discussed in detail below. However, more or fewer struts may be included as needed or required.

[0123] Additionally or alternatively, the step of retracting the first elongated member communicating with the inner cage may include disconnecting the first elongated member and the second elongated member from each other so that the first elongated member can be retracted independently of the second elongated member. Additionally or alternatively, the second elongated member may be a tube. Additionally or alternatively, the first elongated member may be a wire.

[0124] Additionally or alternatively, the first and second elongated members may be located within separate lumens (e.g., lumen 221a and lumen 217a) of the first and second jackets (e.g., the first lubrication jacket 221 and the second lubrication jacket 217) within the microcatheter. Additionally or alternatively, the second elongated member may include a plurality of segments of the first plurality of segments, each of which may include a decreasing outer diameter, thereby forming a taper, and the second elongated member may include a variable stiffness profile along the second elongated member, with the proximal end of the second elongated member being stiffer than the distal end of the second elongated member.

[0125] Additionally or alternatively, the step of retracting the first elongated member communicating with the inner cage may further include sliding the first elongated member proximal or distal within the lumen of the second elongated member.

[0126] Additionally or alternatively, a third predetermined pattern may be a helical cut (e.g., helical cut 126a) which may be a helix having a uniform helical angle that forms a uniform spacing between each rotation of the helix and / or a uniform spacing between each rotation of the helix along the length of the first or second elongated member. Additionally or alternatively, a helical cut (e.g., helical cut 126a) may be a helix having an uneven helical angle that forms an uneven spacing between each rotation of the helix and / or a non-uniform spacing between each rotation of the helix along the length of the first or second elongated member. Additionally or alternatively, a third predetermined pattern may be an intermittent helical pattern (e.g., intermittent helical pattern 126b) placed thereon. An intermittent helical pattern may be a helical cut having a uniform helical angle that forms a uniform spacing between each rotation of the helix and / or a uniform spacing between each rotation of the helix along the length of the first or second elongated member.

[0127] Additionally or alternatively, the intermittent helical pattern may be a helical cut having uneven spacing between each rotation of the helix and / or uneven helical angles that form uneven spacing between each rotation of the helix along the length of the first or second elongated member. The helical cut does not have to be continuous; in other words, there may be multiple cuts interrupted or separated by the material of the first or second elongated member. Additionally or alternatively, the third predetermined pattern may be a radial cut pattern (e.g., radial pattern 126c) arranged thereon. The radial pattern may be a multiple cut perpendicular to the length of the first or second elongated member and uniformly repeated along the length of the first or second elongated member. Additionally or alternatively, the radial pattern may be a multiple cut perpendicular to the length of the first or second elongated member and non-uniformly repeated along the length of the first or second elongated member.

[0128] This disclosure is not limited to the embodiments described, which may vary in configuration and detail. The terms “distal” and “proximal” are used throughout the foregoing description and are intended to refer to location and direction relative to the treating physician. Thus, “distal” or “distal” refers to a location away from the physician or a direction away from the physician. Similarly, “proximal” or “proximal” refers to a location close to the physician or a direction toward the physician.

[0129] 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 similarly to achieve similar purposes. It should also be understood that reference to one or more steps of a method does not preclude the existence of additional method steps or method steps intervening between those explicitly identified steps. Each step of a method can be performed in an order different from that described herein without departing from the scope of the disclosed art. Similarly, reference to one or more components of a device or system should also be understood that does not preclude the existence of additional components or components intervening between those explicitly identified components.

[0130] In the context of this specification, “patient” or “subject” may be a human or any animal. It should be understood that the animal may be any applicable type, but is not limited to mammals, veterinary animals, domestic animals, or pet animals. For example, the animal may be a laboratory animal specifically selected to possess certain characteristics similar to those of a human (e.g., rats, dogs, pigs, monkeys, etc.).

[0131] When used herein, the terms “about” or “approximately” with respect to any number or range of numbers indicate a suitable dimensional tolerance that enables a part or set of components to function in accordance with their intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of values ​​within ±20% of the listed values; for example, “about 90%” may refer to a range of values ​​between 71% and 99%.

[0132] “comprising,” “containing,” “including,” or “having” means that at least the specified compound, element, particle, or method step is present in the composition, 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 specified one.

[0133] It should also be noted that in this specification and the appended claims, the singular forms “a,” “an,” and “the” also include plural references unless otherwise clearly indicated by the context. A range may be expressed herein as a range from one specific value and / or another specific value of “about” or “approximately.” Other exemplary embodiments, when expressing such a range, also include a range from one specific value and / or another specific value.

[0134] The descriptions contained herein are embodiments of the Disclosure and are not intended to limit the scope of the Disclosure in any way. While specific embodiments of the Disclosure are described, various modifications to the devices and methods can be made without departing from the scope and spirit of the Disclosure. For example, while the embodiments described herein refer to specific components, the Disclosure includes other embodiments that utilize various combinations of components to achieve the described functionality, utilize alternative materials to achieve the described functionality, combine components from various embodiments, and combine components from various embodiments with known components. The Disclosure intends to replace the component parts illustrated herein with other well-known commercial products. These modifications will often be obvious to those skilled in the art and are intended to fall within the scope of the following claims.

[0135] [Implementation Method] (1) A method for removing a blood clot, The microcatheter is positioned in close proximity to the blood clot within the blood vessel wall, The outer and inner cages within the lumen of the microcatheter are retracted proximal to expand around the blood vessel wall and engage with a portion of the blood clot. The distance between adjacent posts of the inner cage or the posts of the outer cage is reduced, thereby applying pressure to the portion of the blood clot engaged with the inner or outer post, and thereby clamping the blood clot, by retracting the first elongated member communicating with the inner cage or the second elongated member communicating with the outer cage in the proximal direction. This includes advancing the microcatheter distally over one of the first or second elongated member, A method of advancing the microcatheter to grasp a portion of the blood clot by causing the cells of the inner cage to collapse on the blood clot and exert additional pressure on that portion of the blood clot, or by engaging the blood clot between the distal end of the microcatheter and the cells of the inner cage. (2) The method described above is The method according to Embodiment 1, further comprising the microcatheter, the first elongated member and the second elongated member, the inner cage and the outer cage, and retracting the blood clot from the blood vessel wall. (3) Placing the microcatheter in close proximity to the blood clot Using a clip with a C-shaped feature, The proximal ends of the first elongated member and the second elongated member are attached using the aforementioned C-shaped feature portion, The method according to Embodiment 1, further comprising connecting the first elongated member and the second elongated member by sliding the microcatheter, the first elongated member and the second elongated member simultaneously toward and in close proximity to the blood clot. (4) Retracting the first elongated member that communicates with the inner cage is: The method according to Embodiment 1, further comprising disconnecting the first elongated member and the second elongated member from each other so that the first elongated member can be retracted independently of the second elongated member. (5) The method according to Embodiment 1, wherein the first elongated member and the second elongated member are located in separate lumens of the first jacket and the second jacket within the microcatheter.

[0136] (6) The method according to Embodiment 1, wherein the second elongated member comprises a plurality of first segments, such that each of the plurality of segments reduces its outer diameter, thereby forming a taper, and the second elongated member includes a variable stiffness profile along the second elongated member, with the proximal end of the second elongated member being stiffer than the distal end of the second elongated member. (7) Retracting the first elongated member that communicates with the inner cage, The method according to Embodiment 1, further comprising sliding the first elongated member in a proximal or distal direction within the lumen of the second elongated member. (8) The method according to Embodiment 1, wherein a third predetermined pattern is patterned on the second elongated member in order to achieve a desired rigidity profile along the second elongated member. (9) A blood clot recovery device, Outer cage and An inner cage positioned concentrically within the outer cage, A first elongated member communicating with the outer cage, A second elongated member communicating with the inner cage, A blood clot recovery device equipped with the following features. (10) The blood clot recovery device according to Embodiment 9, wherein the outer diameter of the outer cage is substantially equal to the outer diameter of the blood clot recovery device in an expanded configuration, and thereby both the blood clot recovery device and the outer cage are expanded to a larger diameter below the blood clot or improve juxtaposition with the blood vessel wall when compared to an outer cage of a smaller diameter which is shaped to achieve the outer diameter of the blood clot recovery device, so that both have equal radial forces.

[0137] (11) The blood clot recovery device according to Embodiment 9, wherein the outer diameter of the outer cage is larger than the outer diameter of the blood clot recovery device in the expanded configuration, and thereby expands the outer cage to a larger diameter below the blood clot or improves juxtaposition with the blood vessel wall when compared to an outer cage of a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device, and both the blood clot recovery device and the outer cage have equal radial forces. (12) The blood clot recovery device according to embodiment 9, wherein the outer cage is patterned to include a ring of eight support columns. (13) The blood clot recovery device according to Embodiment 9, wherein the inner cage is patterned to include a ring of four pillars configured to hold a portion of the blood clot. (14) The blood clot recovery device according to Embodiment 9, further comprising a clip, the clip having a c-shaped feature portion at each end of the clip, the feature portion being configured to receive either the first elongated member or the second elongated member, and the clip being configured to connect the first elongated member and the second elongated member when attached. (15) The first elongated member attached to the proximal end of the outer cage, configured to move the outer cage between a delivery configuration and an expansion configuration, The second elongated member is attached to the proximal end of the inner cage and is configured to move the inner cage between a delivery configuration and an expansion configuration, A blood clot recovery device according to embodiment 9, further comprising the above.

[0138] (16) The blood clot retrieval device according to Embodiment 15, wherein the second elongated member comprises a plurality of first segments, so that each of the plurality of segments reduces its outer diameter, so that a taper is formed, and the second elongated member includes a variable stiffness profile along the second elongated member, the proximal end of the second elongated member being stiffer than the distal end of the second elongated member. (17) The distal end of the second elongated member attached to the proximal end of the receptacle, The proximal end of the inner cage, which is installed within the cavity of the receptacle, Furthermore, The blood clot recovery device according to embodiment 15, wherein the second elongated member is slidable within the lumen of the first elongated member. (18) The blood clot recovery device according to embodiment 17, wherein the receptacle further comprises a step within the cavity to reduce the proximal end of the inner cage from being overinserted. (19) The blood clot recovery device according to embodiment 15, further comprising a predetermined pattern on the first elongated member for achieving a desired stiffness profile along the first elongated member. (20) The blood clot recovery device according to Embodiment 15, wherein the first elongated member and the second elongated member are located within the lumen of the first lubricating elongated member jacket and the second lubricating elongated member jacket, respectively, within the microcatheter.

Claims

1. It is a blood clot recovery device, An outer cage having a network of outer supports formed by multiple branched supports, An inner cage having a network of inner supports formed by multiple branched supports positioned concentrically within the outer cage, A first elongated member connected to the outer cage, A second elongated member connected to the inner cage, It is equipped with, The blood clot recovery device further comprises a clip configured to detachably connect the first elongated member and the second elongated member, The clip is removable by the user from the first elongated member and the second elongated member. A blood clot retrieval device wherein the first elongated member and the second elongated member are configured to move independently of each other in the proximal or distal direction when the clip is removed.

2. The blood clot recovery device according to claim 1, wherein the outer diameter of the outer cage is substantially equal to the outer diameter of the blood clot recovery device in an expanded configuration, and thereby expands the outer cage to a larger diameter below the blood clot or improves juxtaposition with the blood vessel wall when compared to an outer cage of a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device, such that both the blood clot recovery device and the outer cage have equal radial forces.

3. The blood clot recovery device according to claim 1, wherein the outer diameter of the outer cage is larger than the outer diameter of the blood clot recovery device in the expanded configuration, thereby expanding the outer cage to a larger diameter below the blood clot or improving juxtaposition with the blood vessel wall when compared to an outer cage of a smaller diameter shaped to achieve the outer diameter of the blood clot recovery device, and both the blood clot recovery device and the outer cage have equal radial forces.

4. The blood clot recovery device according to claim 1, wherein the outer cage is patterned to include a ring of eight support columns.

5. The blood clot recovery device according to claim 1, wherein the inner cage is patterned to include a ring of four pillars configured to hold a portion of the blood clot.

6. The blood clot recovery device according to claim 1, wherein the clip includes a c-shaped feature portion at each end of the clip, and each feature portion is configured to receive either the first elongated member or the second elongated member, and the clip is configured to connect the first elongated member and the second elongated member when attached.

7. The first elongated member is connected to the proximal end of the outer cage and is configured to move the outer cage between a delivery configuration and an expansion configuration, The second elongated member is connected to the proximal end of the inner cage and is configured to move the inner cage between a delivery configuration and an expansion configuration, The blood clot recovery device according to claim 1, further comprising the following:

8. The blood clot recovery device according to claim 7, wherein the second elongated member comprises a plurality of first segments, such that each of the plurality of segments reduces its outer diameter, thereby forming a taper, and the second elongated member includes a variable stiffness profile along the second elongated member, with the proximal end of the second elongated member being stiffer than the distal end of the second elongated member.

9. The distal end of the second elongated member attached to the proximal end of the receptacle, The proximal end of the inner cage, which is installed within the cavity of the receptacle, Furthermore, The blood clot recovery device according to claim 7, wherein the second elongated member is slidable within the lumen of the first elongated member.

10. The blood clot recovery device according to claim 9, wherein the receptacle further comprises a step within the cavity to reduce the proximal end of the inner cage from being excessively inserted.

11. The blood clot recovery device according to claim 7, further comprising a predetermined pattern on the first elongated member for achieving a desired stiffness profile along the first elongated member.

12. The blood clot recovery device according to claim 7, wherein the first elongated member and the second elongated member are located within the lumen of the first lubricating elongated member jacket and the second lubricating elongated member jacket, respectively, within the microcatheter.

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