Method and apparatus for restoring flow

Abstract

A method and device for removing an obstruction from a blood vessel includes an elongate flexible shaft with an expandable capture cage coupled to a distal end of the elongate flexible shaft. The expandable capture cage has an expanded configuration and a collapsed configuration. The collapsed configuration is adapted to be delivered through the blood vessel, and the expanded configuration is adapted to expand within the blood vessel and engulf the obstruction. In one embodiment, the obstruction is a thrombus. In one embodiment, the thrombus comprises a white clot or a red clot.

Description

[Background technology]

[0001] (Priority Claim) This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 035,213, filed June 5, 2020 (Attorney Docket No. 5543.001PRV), the entire contents of which are incorporated herein by reference.

[0002] Blockage of blood vessels is often caused by a blood clot, which may be referred to as a thromboembolic event and may lead to disorders such as stroke, pulmonary embolism, peripheral thrombosis, and the like. Thromboembolic events affect many people each year and can result in morbidity in patients worldwide. Examples of morbidity include ischemia, limb loss, angina, myocardial infarction, stroke, and pulmonary embolism. In some cases, death may result from a thromboembolic event.

[0003] Common existing techniques for treating thromboembolic events include embolectomy, surgery, the use of therapeutic agents such as streptokinase or urokinase or other thrombolytic agents, or thrombectomy devices. Summary of the Invention [Means for solving the problem]

[0004] Blockage of blood vessels is often caused by a blood clot, which may be referred to as a thromboembolic event and may lead to disorders such as stroke, pulmonary embolism, peripheral thrombosis, and the like. Thromboembolic events affect many people each year and result in morbidity in patients worldwide. Examples of morbidity include ischemia, limb loss, angina, myocardial infarction, stroke, and pulmonary embolism. In some cases, death may result from a thromboembolic event.

[0005] Commonly used techniques for treating thromboembolic events include embolectomy, surgery, the use of therapeutic agents such as streptokinase or urokinase or other thrombolytic agents, or thrombectomy devices, to name a few. These treatments provide varying degrees of clinical success and may be suboptimal in some situations.

[0006] Thus, a need exists to provide improved methods and devices for treating thromboembolic events that are safe, clinically effective, easy to use, and cost-effective. It would be advantageous to provide a cost-effective, minimally invasive device that can be precisely deployed in the target treatment area where the clot is to be retrieved. Such a device may also have a small profile to allow it to be delivered with a catheter through tortuous capillaries from a vascular access point to a treatment area far away, as in the case of neurovascular thrombosis, while minimizing disruption of blood flow. At least some of these objectives may be achieved by the embodiments disclosed herein, which generally relate to medical devices and methods used during vascular interventions, such as when treating thromboembolic disorders in the vasculature, including clot removal from cerebral arteries in stroke patients. The present invention provides, for example, the following. (Item 1) 1. A device for removing an obstruction from a blood vessel, said device comprising: an elongate flexible shaft having a proximal end and a distal end; an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage coupled to the distal end of the elongated shaft; Equipped with the expandable capture cage has a collapsed configuration and an expanded configuration; In the collapsed configuration, the expandable capture cage is adapted to be delivered through the blood vessel; In the expanded configuration, the expandable capture cage is configured to expand into and engulf the obstruction so that the obstruction can be removed from the vessel by proximal retraction of the expandable capture cage. (Item 2) Item 1, wherein the obstruction is a thrombus. (Item 3) 3. The device of item 2, wherein the thrombus comprises a white clot or a red clot. (Item 4) Item 10. The device of item 1, wherein the elongate flexible shaft is a guidewire. (Item 5) Item 10. The device of item 1, wherein the expandable cage is self-expanding. (Item 6) Item 1, wherein the proximal end of the expandable capture cage is open and has a proximal edge that is at an oblique angle relative to the longitudinal axis of the expandable capture cage. (Item 7) Item 1, the device of item 1, wherein the proximal end of the expandable capture cage comprises a plurality of open or closed rings, each open or closed ring in the plurality of open or closed rings comprising one or more closed cells, each open or closed ring having a total number of closed cells that decreases in the proximal direction until the most proximal ring is an open ring having a single closed cell. (Item 8) Item 1, wherein the proximal end of the expandable capture cage comprises a plurality of rings, at least some of the plurality of rings being open rings with gaps disposed between opposing edges of the open rings, the gaps increasing in a proximal direction. (Item 9) Item 1, the device of item 1, wherein the expandable cage comprises a plurality of struts coupled together, and at least some of the struts located on the proximal end of the expandable cage have a width or thickness that is less than some of the struts located distally thereof. (Item 10) Item 10. The device of item 1, wherein the expandable cage is tapered from a proximal end of the expandable cage to a distal end of the expandable cage. (Item 11) Item 1, wherein the expandable cage comprises a plurality of closed cells, the plurality of closed cells having a lemon shape. (Item 12) Item 12. The device of item 11, wherein the closed cell comprises a tapered proximal end, a tapered distal end, an apex between the tapered proximal end and the tapered distal end, and a valley between the tapered proximal end and the tapered distal end. (Item 13) Item 10. The device of item 1, wherein the expandable cage comprises a plurality of closed cells, the plurality of closed cells comprising a plurality of concave contours and a plurality of convex contours. (Item 14) some of the plurality of closed cells include six S-shaped or inverted S-shaped struts; the first S-shaped strut has a distal end with an outwardly facing concave region and a proximal end with an inwardly facing concave region; the second S-shaped strut has a distal end with an outwardly facing concave region and a proximal end with an inwardly facing concave region; a third inverted-S-shaped strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; a fourth S-shaped strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; a fifth S-shaped strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; a sixth inverted-S-shaped strut having a proximal end with an inwardly facing concave region and a distal end with an outwardly facing concave region; Item 14. The device according to item 13. (Item 15) a proximal end of the first S-shaped strut is coupled to a distal end of the second S-shaped strut; a proximal end of the second S-shaped strut is coupled to a distal end of the third inverted S-shaped strut; a proximal end of the third inverted-S strut coupled to a proximal end of the fourth inverted-S strut; a distal end of the fourth S-shaped strut is coupled to a proximal end of the fifth S-shaped strut; a distal end of the fifth S-shaped strut is coupled to a proximal end of the sixth inverted S-shaped strut; a distal end of the sixth inverted S-shaped strut is coupled to a distal end of the first S-shaped strut; Item 15. The device according to item 14. (Item 16) Item 14. The device of item 13, wherein the proximal end of the expandable cage comprises a plurality of lemon-shaped cells and a plurality of diamond-shaped cells. (Item 17) Item 17. The device of item 16, wherein the plurality of lemon-shaped cells comprise an S-shaped strut, a first linear strut, a second linear strut, and an inverted S-shaped strut, wherein the S-shaped strut is coupled to the first linear strut, the first linear strut is coupled to the second linear strut, the second linear strut is coupled to the inverted S-shaped strut, and the inverted S-shaped strut is coupled to the S-shaped strut. (Item 18) Item 17. The device of item 16, wherein the plurality of diamond-shaped cells comprises four linear posts joined together. (Item 19) Item 17. The device of item 16, wherein the proximal end of the expandable cage comprises a decreasing number of diamond-shaped cells, and the last diamond-shaped cell in the decreasing number of diamond-shaped cells is coupled with the elongated shaft. (Item 20) Item 1, wherein the proximal end of the expandable capture cage overlaps with and terminates in a single strut coupled to the distal end of the elongate shaft. (Item 21) 21. The device of claim 20, further comprising a filament helically disposed around the single strut and the elongate shaft to form a flexible radiopaque joint. (Item 22) Item 14. The device of item 13, wherein the distal end of the expandable cage comprises a plurality of lemon-shaped closed cells, each lemon-shaped closed cell having a pointed distal region. (Item 23) The lemon-shaped closed cell comprises four S-shaped or inverted S-shaped struts; the first S-shaped strut has a distal end with an outwardly facing concave region and a proximal end with an inwardly facing concave region; a second inverted-S-shaped strut having a distal end with an inwardly facing concave region and a proximal end with an outwardly facing concave region; a third S-shaped strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; a fourth inverted-S-shaped strut having a proximal end with an inwardly facing concave region and a distal end with an outwardly facing concave region; Item 23. The device according to item 22. (Item 24) a proximal end of the first S-shaped strut is connected to a distal end of the second inverted S-shaped strut to form an apex in the lemon-shaped closed cell; a proximal end of the second inverted S-shaped strut is joined to a proximal end of the third S-shaped strut to form a pointed proximal end of the lemon-shaped closed cell; a distal end of the third S-shaped strut is connected to a proximal end of the fourth inverted S-shaped strut to form a valley in the lemon-shaped closed cell; a distal end of the fourth inverted S-shaped strut is joined to a distal end of the first S-shaped strut to form a pointed distal end of the lemon-shaped closed cell; Item 24. The device according to item 23. (Item 25) Item 25. The device of item 24, wherein the peaks of the closed cells are inwardly facing and concave, and the valleys of the closed cells are inwardly facing and concave. (Item 26) Item 23. The device of item 22, wherein the distal end of the expandable capture cage comprises a plurality of linear struts coupled to pointed distal regions of the plurality of lemon-shaped cells, the linear struts tapering distally to a point forming a closed porous tip configured to prevent the obstruction from passing therethrough. (Item 27) 27. The device of claim 26, further comprising a helical coiled filament disposed around the linear strut and forming an atraumatic radiopaque tip. (Item 28) 1. A system for removing an obstruction from a blood vessel, the system comprising: The device according to item 1, a microcatheter or device slidably disposed thereover; A system comprising: (Item 29) Item 29. The system of item 28, further comprising a sheath slidably positioned over the microcatheter. (Item 30) 1. A method for removing an obstruction from a blood vessel, the method comprising: providing a clot retrieval catheter comprising an expandable capture cage coupled to an elongated flexible shaft; introducing the clot retrieval catheter into the blood vessel; advancing the expandable capture cage through the blood vessel to the obstruction; radially expanding the expandable capture cage to engage the obstacle; entangling the obstacle with the expandable capture cage; removing the obstruction from the blood vessel with the clot retrieval catheter; removing the clot retrieval catheter from the blood vessel; A method comprising: (Item 31) 31. The method of claim 30, wherein advancing the expandable capture cage through the blood vessel comprises advancing the elongate flexible shaft through a microcatheter. (Item 32) 32. The method of claim 31, wherein advancing the expandable capture cage comprises advancing the expandable capture cage distal to the obstruction or advancing the microcatheter distal to the obstruction. (Item 33) 32. The method of claim 31, further comprising advancing the microcatheter over a guidewire and removing the guidewire from the patient before introducing the clot retrieval catheter into the blood vessel. (Item 34) 31. The method of claim 30, wherein the obstruction comprises a thrombus. (Item 35) 35. The method of claim 34, wherein the thrombus comprises a white clot or a red clot. (Item 36) 31. The method of claim 30, wherein the blood vessel is an arterial blood vessel in the patient's head. (Item 37) 31. The method of claim 30, wherein radially expanding the expandable capture cage comprises retracting the microcatheter proximally away from the expandable capture cage to remove the constraint therefrom. (Item 38) Item 31. The method of item 30, wherein radially expanding the expandable capture cage comprises self-expanding the expandable capture cage. (Item 39) Item 31. The method of item 30, wherein radially expanding the expandable capture cage includes expanding a plurality of closed cells formed with a plurality of S-shaped and inverted S-shaped struts coupled together. (Item 40) 31. The method of claim 30, further comprising: the obstruction preventing a tapered tip from exiting a distal end of the expandable capture cage coupled thereto. (Item 41) 31. The method of claim 30, wherein removing the obstruction from the blood vessel comprises proximally retracting the expandable capture cage. (Item 42) Item 42. The method of item 41, wherein proximally retracting the expandable capture cage comprises retracting a beveled proximal edge of the expandable capture cage toward a distal end of a microcatheter or sheath. (Item 43) 31. The method of claim 30, further comprising visualizing radiopaque markers on the expandable capture cage using fluoroscopy. [Brief explanation of the drawings]

[0007] In the drawings, which are not necessarily drawn to scale, like numbers may describe similar components in different views. Like numbers with different suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0008] [Figure 1] FIG. 1 shows a perspective view of an embodiment of a device for removing an obstruction from a patient.

[0009] [Figure 2] FIG. 2 shows the device of FIG. 1 with optional radiopaque markers.

[0010] [Figure 3A] FIG. 3A shows a side view of an example of an expandable capture cage that can be used in conjunction with any device for removing an obstruction.

[0011] [Figure 3B] FIG. 3B shows a perspective end view of the cage of FIG. 3A.

[0012] [Figure 4A] FIG. 4A illustrates the expandable capture cage of FIG. 3A shown in a flat, unrolled configuration.

[0013] [Figure 4B] FIG. 4B shows the expandable cage of FIG. 4A in a flattened and unrolled configuration with arcuate struts at the distal tapered tip.

[0014] [Figure 5] FIG. 5 shows the expandable capture cage of FIG. 3A with optional flexible regions.

[0015] [Figure 6A] FIG. 6A shows the expandable capture cage of FIG. 3A with various optional strut dimensions.

[0016] [Figure 6B]FIG. 6B shows the expandable capture cage of FIG. 3A with a taper.

[0017] [Figure 7] FIG. 7 shows the expandable capture cage of FIG. 3A with optional double struts and optional radiopaque markers in an unrolled and flattened configuration.

[0018] [Figure 8A] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8B] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8C] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8D] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8E] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8F] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8G] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8H] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8I] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8J]8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein. [Figure 8K] 8A-8K illustrate an example of a method for removing a blood clot from a patient using any of the devices disclosed herein.

[0019] [Figure 9] FIG. 9 shows another embodiment of an expandable capture cage in a flat, unrolled configuration.

[0020] [Figure 10A] FIG. 10A shows a perspective view of the embodiment of FIG. 9 in an expanded configuration.

[0021] [Figure 10B] FIG. 10B shows the embodiment of FIG. 9 in a collapsed configuration.

[0022] [Figure 11] FIG. 11 shows an embodiment of a distal tapered end of a capture cage as in FIG.

[0023] [Figure 12A] 12A-12C show an example of the distal end of a tapered capture cage with a coil tip. [Figure 12B] 12A-12C show an example of the distal end of a tapered capture cage with a coil tip. [Figure 12C] 12A-12C show an example of the distal end of a tapered capture cage with a coil tip.

[0024] [Figure 13A] 13A-13B show an embodiment of the proximal end of a capture cage coupled to a guidewire. [Figure 13B] 13A-13B show an embodiment of the proximal end of a capture cage coupled to a guidewire. DETAILED DESCRIPTION OF THE INVENTION

[0025] Detailed Description 1 shows an example of a device 100 for removing an obstruction, such as a blood clot, from a patient. The device may be referred to herein as a stent retriever, a clot retriever, a clot retrieval catheter, or a device for removing obstructions. Device 100 may be used to remove a blood clot or other obstruction from a patient and includes a proximal end 102, a distal end 104, a thicker proximal portion of an elongated flexible shaft 110, a thinner distal portion 116 of the elongated flexible shaft, and an expandable capture cage 108 that is mesh-like and porous to allow blood to flow through the pores of the cage to avoid causing ischemia, while still maintaining a small enough pore size to ensure that the capture cage can capture a blood clot or other obstruction without thrombus escaping the capture cage. The thicker proximal portion of the elongate flexible shaft 110 may be formed from a thinner distal portion 116 of the elongate flexible shaft that is disposed within a microcatheter or sheath, or the thinner distal portion 116 of the elongate flexible shaft may simply be thicker to provide a stiffer shaft with better extrudability. The proximal end of the expandable capture cage 108 is coupled to the distal end of the thinner portion of the elongate flexible shaft 116.

[0026] In this example, the elongate shaft is a pusher wire, also referred to as a guidewire. The proximal portion 110 of the pusher wire may have any cross-section, but may be round, and has a larger diameter than the distal, thinner section 116, which may also have any cross-section, but may also be round and thinner than the proximal section. The thicker proximal section provides better pushability of the device through the vessel, while the thinner distal section provides additional flexibility for navigating tortuous blood vessels, such as those within the brain. Once the device is delivered to the target treatment area, the expandable capture cage 108 radially expands, either by balloon expansion or self-expansion. In this example, the capture cage is made of a shape-memory metal or superelastic material, such as nitinol, so that the capture cage self-expands. The length of the elongate shaft and sheath that constrains the capture cage depends on where the treatment area is located within the patient's body and, therefore, may be any desired length.

[0027] Optionally, in any embodiment of the device, the proximal and distal ends of the capture cage 108 may include collars 112, 114 for holding the proximal and distal struts of the capture cage together. The proximal collar 112 may also be used to crimp the proximal struts of the capture cage onto the distal end of the extension shaft 116, or the collar may be a radiopaque marker, as discussed below. In some embodiments, the collar is a separate cylindrical element placed over the struts of the expandable cage and the guidewire 116. In other embodiments, the collar may be uncut tubing from which the expandable cage is made, and thus the collar is a cylindrical tube that is integral with the struts of the expandable cage. In any embodiment, the obstruction to be treated may be a blood clot located within a blood vessel (such as an artery) in the patient's head or anywhere within the body. The proximal end of the capture cage may include a beveled open end 118 to facilitate partial or complete proximal retraction of the expandable cage 108 into a sheath or microcatheter, if desired. The distal end of the capture cage may be porous to allow blood to flow therethrough to avoid ischemia, yet still include a tapered conical tip 106 to capture clots or other obstructions and prevent clots from escaping the capture cage. Multiple struts in the capture cage extend distally and converge to a point, forming the tapered tip. A collar 114 may be used to crimp or hold the struts together. As mentioned above, the collar 114 may be a separate cylindrical element, or it may be uncut tubing from which the expandable cage is formed, such that the collar 114 is integral with the expandable cage 108. The collar 114 may also serve as a radiopaque marker to allow the operator to visualize the distal end of the device under fluoroscopy. Several geometries may be used to form the cells in the capture cage, examples of which may be used as disclosed herein.

[0028] Optionally, in any embodiment, the thicker proximal end 102 of the guidewire may be coupled to a handle (not shown) to allow the operator to easily manipulate the device during use.

[0029] FIG. 2 shows the same embodiment as FIG. 1 , except that the proximal and distal collars 112, 114 are also radiopaque markers that allow an operator, such as an interventional neurologist or radiologist, to visualize the ends of the capture cage under fluoroscopy during a procedure to remove an obstruction, such as a blood clot, from a patient. Any high-density material, such as platinum, gold, or other materials known in the art, may be used as the radiopaque marker. The collars 112, 114 may also be used to help crimp the struts of the capture cage together, or to join the struts to the distal end of the extension shaft 116, or to form a tapered distal tip. As discussed above, the collars may also be uncut tubing from which the expandable cage is formed, and thus are integral with the struts of the expandable cage. Other aspects of FIG. 2 are generally identical to FIG. 1 . The use of radiopaque markers in this embodiment is optional, and the radiopaque markers disclosed herein may optionally be used in any embodiment of the capture cage disclosed herein.

[0030] FIG. 3A shows a side view of an expandable capture cage 300 that may be used in any of the embodiments of the obstruction removal device disclosed herein. The expandable capture cage 300 is shown in an expanded configuration and includes a proximal end 302 that is coupled to the distal end of an elongated shaft (not shown in FIG. 3A ), which may be a guidewire or other elongated shaft, so that the device may be advanced through a patient's vasculature to a target treatment area and then retracted and removed upon completion of the procedure. The proximal end 302 may include an open beveled end, as previously described above and as will be further described elsewhere in this disclosure. The expandable capture cage 300 also includes a distal end 306 that may also include a tapered conical distal tip 308 formed from several struts that extend distally from the distal end of the expandable capture cage and converge to a point. The tapered conical distal tip 308 serves as a distal filter trap to prevent clots or other debris from exiting the distal end of the expandable capture cage, and has sufficient porosity due to the openings between the struts to allow blood to flow through the tapered conical distal tip (thereby avoiding causing ischemia), but the openings are small enough to minimize or prevent clots or other debris from passing therethrough. The thickness or width of the struts at the tapered conical distal tip may be less than 3 mm, 2.5 mm, 2 mm, or any other size in any embodiment. The strut thickness or width at the tapered conical distal tip may be thicker, thinner, or the same as the struts in the main body of the expandable cage. The main body 310 of the expandable capture cage is generally cylindrically shaped and includes interconnected struts 314 that form closed cells. The openings in the closed cells forming the cage wall are similarly porous enough to allow blood to flow therethrough to prevent ischemia, while still trapping clots or other debris and preventing it from passing through the side walls of the expandable cage. The expandable cage includes several circumferentially oriented rings 312 that extend axially along the longitudinal axis of the expandable cage and form the cage.The struts 314 form closed cells in each ring, which may be completely closed or whose edges may not be joined together, thereby forming open rings with gaps between the ring edges. For example, in the example of FIG. 3A , at least the first two rings in the proximal bevel region of the expandable cage are open rings, while the remaining rings in the body of the expandable cage are closed rings, with the distal conical tip having its unique configuration in which the linear struts converge to a point, forming a tapered tip. Adjacent rings may be joined together to form a cylindrical tube that is the expandable cage, and adjacent closed cells may share common struts. In this example, the closed cells are lemon-shaped, and each lemon-shaped closed cell is formed by connecting several S-shaped and inverted S-shaped struts together to form the lemon-shaped peaks and valleys and the lemon-shaped pointed proximal and distal ends. Additional disclosure related to cell geometries is disclosed herein. Each strut generally has a thickness related to the wall thickness of the hypodermic tubing used to form the cage by laser cutting, photoetching, electrical discharge machining, or other techniques known in the art. The strut thickness along the cage may be the same, or the strut thickness may vary to provide different mechanical properties along the length of the cage, such as providing stiffer and more flexible regions. The strut thickness may be varied by grinding, electropolishing, or other processes known in the art. Similarly, the strut length and width may also be constant along the length of the cage, or they may vary in different regions to provide regions with desired mechanical properties. For example, the proximal struts in a cell may be thicker than the other struts in the cell to provide a stiffer edge and more support, as well as more surface area for better engagement and entrapment of the cage with the clot.

[0031] Figure 3B shows a perspective end view of the proximal end of the expandable cage 300 of Figure 3A, highlighting the open proximal end with a tapered bevel that is described in more detail in the flat pattern of Figure 4A below. The other side of Figure 3B generally takes the same form as in Figure 3A. Figure 3B also shows an extension shaft that is coupled to the proximal end of the expandable capture cage with a collar.

[0032] Figure 4A shows the stent retriever device (also referred to as a clot retriever or a device for removing obstructions) of Figure 3A, but with the expandable capture cage in an unrolled and flattened configuration for easy visualization of the cell geometry. Expandable capture cage 300 has a proximal end 402 and a distal end 404 and an intermediate section (also referred to as a central section or central body) or body 406 disposed therebetween. Proximal end 402 is coupled to an elongated shaft 408, which may include an optional radiopaque marker band, and may be a guidewire or collar as discussed above, or separate cylindrical or uncut tubing collars may be coupled to proximal and distal ends 402, 404 to aid in identifying the ends of the expandable cage under fluoroscopy during use.

[0033] The expandable capture cage central body 406 includes multiple circumferentially oriented rings 424, 426 joined together at connection points 412. The space between adjacent joined rings 424, 426 may also be considered a ring 436, although those skilled in the art will understand that this ring is formed by joining adjacent rings and, therefore, struts in a cell of a ring 436 are shared with cells in the adjacent ring with a common boundary. Each ring in the central body 406 may be a closed ring formed from multiple closed cells 422. The device may have any number of rings to create a capture cage of a desired length to accommodate the treatment area. Similarly, the diameter of the closed cells may be adjusted to provide an expandable capture cage of an appropriate diameter to treat different vessel sizes. In this example, the rings 424, 426, 436 in the central body 406 each have four closed lemon-shaped cells, but this is not intended to be limiting, and the number of closed cells may be varied. Each lemon-shaped closed cell is formed from four struts 414, 416, 418, 420, two S-shaped struts 414, 420 (proximal to distal), and two inverted S-shaped struts 416, 418 (proximal to distal), which are joined together to form a lemon shape. The S-shaped struts 414, 420 have a compound curve with a concave region facing outward away from the center of the closed cell and a concave region facing inward toward the center of the closed cell. The inverted S-shaped struts 416, 418 have a compound curve with a concave region facing inward toward the center of the closed cell and a concave region facing outward away from the center of the closed cell. In this example, in a clockwise direction, there is a first S-shaped strut, followed by an inverted S-shaped strut, followed by an S-shaped strut, followed by an inverted S-shaped strut. Thus, a closed cell has a concave outward facing region followed, in a clockwise direction, by a concave inward facing region followed by a concave outward facing region followed by a concave inward facing region followed by a concave inward facing region followed by a concave outward facing region. Opposite ends of the struts are joined together to close the cell. Each cell is expandable, thereby imparting radial expansion to each ring in the cage.The cage may be balloon expandable or formed using a superelastic or shape-memory alloy such as Nitinol so that the cage is self-expanding. The lemon-shaped closed cells have an accreting proximal end and a tapered distal end. The proximal accreting begins at the proximal point and accretes to a maximum cell width, and the distal taper begins at the maximum cell width and tapers to a distal point. Each lemon-shaped closed cell also includes an apex at the upper portion of the closed cell at its maximum width and a valley or depression at the lower portion of the cell at its maximum width. The apex and valley are generally located between the proximal and distal ends of the closed cell. The proximal and distal ends of the lemon-shaped cell have respective pointed regions extending in the proximal or distal direction.

[0034] The proximal end 402 of the cage may have an open beveled edge 410. This is formed by reducing the number of closed cells in each ring moving proximally as the ring transitions from a fully closed ring to an open ring. Here, the last closed ring has four closed cells, followed by an open ring of three closed cells, followed by an open ring of two closed cells, followed by an open ring of one closed cell, all of which are molded to form the cylindrically shaped cage wall. Thus, the wall is fully closed due to a fully closed ring of four closed cells, then the wall partially opens, becoming increasingly open moving proximally from an open ring of three closed cells to two closed cells to one closed cell. The open gap between the edges of the open rings will increase proximally as fewer and fewer closed cells form each ring. The angle 440 formed by the edge of the proximal strut may be any angle, but in this embodiment may be less than or equal to 90 degrees, less than or equal to 60 degrees, less than or equal to 45 degrees, or less than or equal to 30 degrees. The angle in any embodiment may have a maximum angle greater than or equal to zero degrees, less than 90 degrees, less than or equal to 60 degrees, less than or equal to 45 degrees, or less than or equal to 30 degrees.

[0035] Also, as discussed, the distal tip 404 in this example is a tapered distal tip or distal trap formed from several linear struts that extend distally from the distal end of the cage and converge radially inward to a point where their ends are twisted, knotted, crimped, bonded, welded, or otherwise joined together to form the porous distal tapered tip. The linear struts 432, 434 may be longer or shorter relative to each other depending on where they are joined on the distal end of the cage as a mechanism for accommodating different amounts of shortening on the cage. For example, a short strut 432 may be joined to the distal pointed portion 430 of a lemon-shaped closed cell, and a longer strut 434 may be joined to the lower or upper portion 438 of the lemon-shaped cell (which may also be referred to as the top or valley or widest portion of the cell). The pointed portion 430 moves axially different amounts from the lower or upper portion 438 during expansion or contraction of each cell during radial expansion of the cage, and therefore the different lengths accommodate this different amount of shortening and maintain the uniform shape of the tapered distal tip. In other embodiments, the struts at the distal tip may be connected to the intermediate portion 428 between the distal point and the peak or valley of the lemon-shaped closed cell.

[0036] FIG. 4B shows only the distal portion of the expandable cage 300 of FIG. 4A. The primary difference is the use of arcuate struts 450 at the distal tapered tip. Here, the arcuate struts 450 may be connected to the pointed distal portions of the lemon-shaped cells, or they may be connected to any other portion of the closed lemon-shaped cells as described herein. The arcuate struts include a long linear portion connected to the distal-most closed cell and a curved distal portion. The curved distal portion may be undulating, S-shaped, sinusoidal, serpentine, or any other pattern that allows axial expansion and contraction of the struts 450 during radial expansion and collapse of the expandable cage. The undulating struts thus help accommodate shortening of the cage during expansion and contraction. Other aspects of the expandable cage may be identical to those in FIG. 4A, or features from other embodiments of the expandable cage may be used in combination with or substituted for the features of FIG. 4A. The struts illustrated in FIG. 4B may optionally be used in any of the capture cage embodiments disclosed herein.

[0037] 5 shows an embodiment of an expandable capture cage 300 that is identical to that shown above in FIG. 3A, the only difference being that the expandable capture cage 300 includes an optional flexible region 502 in the capture cage. The flexible region may be located anywhere along the length of the expandable cage, for example, midway (halfway between the proximal and distal ends of the expandable cage), at 1 / 3 of the length of the expandable cage and closer to the proximal end of the cage, or at 2 / 3 of the length of the expandable cage and closer to the distal end, or any other location. In the case of a flexible region in the middle, two cage sections are formed, while when the flexible region is located at 1 / 3 of the length of the cage and at 2 / 3 of the length of the cage, three sections are created. This is not intended to be limiting, and any number or location of flexible joints may be employed. The flexible joints may be located anywhere along the circumference of the expandable cage; for example, if the cross section of FIG. 5 were represented by a circle and a clock were superimposed on the cross section, the flexible joints could be located at one or more positions, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 o'clock. As an example, two flexible joints may be located at the top and bottom of the cage, at the 12 and 6 o'clock positions or the 3 and 9 o'clock positions. Flexible regions are formed by creating a discontinuity or gap between adjacent closed cells at the proximal or distal points of adjacent lemon-shaped cells. In the example of FIG. 5, there are two flexible regions formed by decoupling adjacent closed cells. Each flexible region allows the portions of the expandable cage on either side of the gap to flex relative to each other, thereby creating a flexible region. This allows for more flexing during delivery through tortuous vessels or allows the expandable cage to more easily conform to local contours of the anatomy. Additionally, when the expandable cage is constrained by a sheath and then partially retracted, the flexible region allows for full expansion of the distal portion of the unsheathed flexible cage. The flexible region may be formed by severing the connection points between adjacent closed cells, forming a gap or discontinuity.The cutting may be performed during the manufacture of the expandable cage, or it may be performed by a physician operator immediately prior to delivery to the patient and may be customized as needed. Flexible regions may be positioned at any location circumferentially around each ring of the expandable cage or at any axial location along the longitudinal axis of the expandable cage; therefore, the expandable cage may have any number of flexible regions. The strut width or thickness at the connection point adjacent or adjacent to the gap may exceed the other struts to provide increased strength around the gap. Radiopaque markers may be positioned adjacent the gap so that the operator can visualize the flexible region under fluoroscopy. Other aspects of the expandable cage are generally identical to the embodiment in FIG. 3A . Therefore, the flexible joints may optionally be combined with or substituted for any of the features disclosed with respect to the embodiment in FIG. 3A or any of the expandable cage embodiments disclosed herein.

[0038] FIG. 6A shows another embodiment of the expandable capture cage 300 that is identical to that previously shown in FIG. 3A, with the only difference being that the expandable capture cage 300 optionally includes thinner struts on the open bevel proximal region. The struts 606 in the main body of the expandable cage have a thickness and width. The thickness is generally dictated by the wall thickness of the tubing from which the expandable cage is cut, but this may also be controlled by grinding, electropolishing, or other methods known in the art. Also, the strut width is controlled by a laser or other tube cutting process. In the embodiment of FIG. 6A, the struts 604 in the proximal open bevel region 608 (sometimes referred to as the proximal taper) may have a thickness or width that is less than that of the struts 606 in the main body of the expandable cage. For example, the strut width may be 25-50 microns in the proximal portion. The reduced thickness or width of the struts in the proximal portion of the cage allows the proximal end of the cage to collapse more easily due to reduced radial strength, and therefore the expandable cage can be more easily retracted into a sheath or microcatheter when re-deployment is performed. The proximal open beveled region 608 is coupled to a distal portion of an elongate shaft 602, such as a guidewire. Other aspects of the expandable cage 300 of FIG. 6A are substantially identical to the embodiment in FIG. 3A. Thus, the reduced strut dimensions described with respect to FIG. 6A may optionally be used in conjunction with or substituted for any of the features in the embodiment of FIG. 3A or any of the other embodiments of the expandable cage disclosed herein.

[0039] FIG. 6B shows another embodiment of an expandable capture cage 300 identical to that previously shown in FIG. 3A, the only difference being that the expandable cage 300 is optionally tapered along its length. A portion of the expandable capture cage may be tapered, or the entire length of the capture cage may be tapered. Tapering allows the capture cage to better conform to the vascular anatomy, thereby allowing for better apposition of the cage with the vessel wall. In this embodiment, the diameter 610 of the proximal end of the cage in the expanded configuration is larger than the diameter 612 of the distal end of the capture cage in the expanded configuration. Other aspects of the catheter and capture cage are substantially identical to those previously described with respect to the previous embodiments, including FIGS. 3 and 6A, including the elongated shaft 602, optional various strut dimensions 604, 606 (described with respect to FIG. 6A), proximal bevel 608, etc. Thus, any of the features disclosed in FIG. 6B may be used in combination with or substituted for any of the features of any of the other expandable cages disclosed herein.

[0040] Figure 7 shows another embodiment of an expandable cage that can be used in conjunction with any of the devices for removing obstructions from a patient disclosed herein. Expandable cage 300 is identical to that shown in Figure 3A, with the primary difference being that cage 300 in Figure 7 includes an optional double-strut region and optional radiopaque markers that can be used in any of the embodiments of the expandable cage disclosed herein.

[0041] The expandable cage 300 shown in FIG. 7 is identical to that previously shown in FIG. 3A, with the primary differences being the use of optional double struts, optional flexible regions, and optional radiopaque markers. The double struts provide additional stiffness and strength along the edges of the cells with double struts and also aid in roll-up and clot removal and improved visualization under fluoroscopy due to the increased surface area. FIG. 7 shows the expandable cage unrolled and flattened. The expandable cage 300 has a proximal tapered or beveled edge 704 coupled to an elongated shaft 702, which may be a guidewire with or without any of the collars previously described. Other aspects of the proximal tapered edge are substantially identical to those discussed previously with respect to FIG. 3A. Similarly, the distal portion 718 of the cage is also identical to the distal portion of the cage of FIG. 3A, including a tapered distal cone or tip that acts as a trap to prevent clots or other debris from exiting the cage while still allowing blood flow therethrough.

[0042] The struts of the expandable cage include radiopaque markers to help the physician operator visualize the cage under fluoroscopy during the procedure. The radiopaque markers may be located anywhere along the cage. For example, the proximal end of the cage may include a radiopaque marker 706 on the proximal strut of the closed cells, but this is not intended to be limiting. Each ring may include a radiopaque marker, or other radiopaque marker patterns may be used. In this example, which is not intended to be limiting, the radiopaque markers are located on the proximal S-shaped struts of the closed lemon-shaped cells, and each ring includes at least two closed cells, with radiopaque markers with unmarked closed cells positioned therebetween. Adjacent rings may have the same radiopaque marker pattern, such that the radiopaque markers extend in a linear array along the longitudinal axis of the cage. A ring formed by two adjacent rings connected together (e.g., a ring with a cell that shares a strut with an adjacent cell) may or may not include a radiopaque marker; in this example, no markers are present in that ring.

[0043] The distal portion of the expandable cage may have the same radiopaque marker pattern as the proximal portion, or it may have a different pattern. The middle portion 714 of the expandable cage, which may be half, one-third, or one-quarter of the cage's length, may have a denser pattern of radiopaque markers 708. Here, the radiopaque markers 708 are increased on each closed cell. For example, here, at least some of the closed cells in the middle portion include four radiopaque markers 708, one on each of the four struts (two S-shaped and two inverted S-shaped struts) that make up the closed cell. This helps ensure that the expandable cage is aligned with the clot or other obstruction to be removed from the patient. Also, because the cage self-expands to engage the vessel wall, having additional markers helps the operator visualize the overall three-dimensional shape of the expanded cage, which will reflect any abnormalities in the vessel wall, such as plaque, that may prevent or obstruct full cage expansion.

[0044] 7 also illustrates the use of optional flexible regions 716, 720, 722, as previously described. The flexible regions are formed by leaving adjacent closed cells uncoupled, creating a gap between them, allowing the cage to flex around the gap. Here, the flexible regions include two flexible regions (716 and 722 are the same flexible region), which are located in the middle portion of the cage, although they may be located anywhere along the cage and any number may be used.

[0045] The embodiment of FIG. 7 also optionally includes dual parallel struts 712 extending diagonally along the flattened view, but in a rolled-up cylindrical view of the cage, the dual struts would appear as a spiral around the cylindrically shaped cage. The dual struts may also be formed by several S-shaped struts connected together along a spiral line in the rolled-up cylindrical view (a diagonal line in the unrolled view). Here, optionally, there are two dual-strut regions. The dual-strut regions provide two stiffer regions of the cage and stiffer edges that help the cage expand into clots or obstructions and also provide stiffer edges that can slide through clots or obstructions, cutting them as the cage is advanced or retracted. A small slit or gap is disposed between the dual struts. Optionally, in this embodiment, the dual struts may also include a radiopaque marker 710 on one or both of the dual struts to facilitate visualization under fluoroscopy during the procedure.

[0046] Other aspects of the expandable cage 300 of Figure 7 are generally the same as those previously described in Figure 3A or any of the other cage embodiments disclosed herein. Any of the features disclosed with respect to Figure 7 may be used in conjunction with or substituted for any of the features described in Figure 3A or any other embodiment of the expandable cage disclosed herein. Thus, optionally, the expandable cage may include any permutation or combination of cell geometries, any of the radiopaque marker patterns, any of the strut dimensions, any of the proximal bevel features, any of the distal tapered tip features, dual strut patterns, flexible region patterns, elongated shaft features, etc.

[0047] 8A-8I illustrate an example of treating a patient suffering from a stroke caused by a blood clot in an artery of the brain. This is not intended to be limiting, and one skilled in the art will understand that the devices and methods disclosed herein can be used to treat blood clots or obstructions in other parts of the body's blood vessels.

[0048] In Figure 8A, a cerebral artery A is shown with a blood clot C that has occluded the vessel, preventing or restricting oxygenated blood from flowing past the blockage, thereby causing a stroke due to ischemia. The clot may completely or partially occlude blood flow through the vessel.

[0049] 8B, a guidewire GW is percutaneously introduced into a blood vessel, typically an artery, and advanced through the blood vessel, through the clot, and distal to the clot. The guidewire may be percutaneously introduced into the blood vessel using a standard procedure, such as a Seldinger procedure, or using a surgical incision. Examples of access points may include the groin, wrist, neck, etc., and the guidewire may be advanced within any blood vessel, such as any artery (e.g., femoral artery, carotid artery, radial artery, etc.) or vein, using known access techniques.

[0050] Once the guidewire is in place, it acts as a rail over which the microcatheter can be advanced to the treatment site. In Figure 8C, a microcatheter 802 with a lumen is advanced distally over the guidewire GW within the diseased artery A to the clot C. The microcatheter may be a single lumen catheter that provides a tunnel through which a stent retriever catheter (sometimes also referred to herein as a clot retriever or a device for removing obstructions) can be advanced through the vessel to the treatment site. The size of the microcatheter may be selected based on the vessel to be treated.

[0051] FIG. 8D illustrates the optional use of a sheath S. Here, after the guidewire is inserted, a sheath (e.g., a guide sheath) may be advanced over the guidewire GW. The microcatheter is then advanced over the guidewire GW and through the lumen of the sheath S until the microcatheter is adjacent to or abutting the clot C. Thus, if a sheath is used, FIG. 8D replaces FIG. 8C. Once the microcatheter is properly advanced and positioned, the sheath may either remain in place, or be retracted proximally to move it out of the way but remain within the vessel, or the sheath may be removed from the vessel entirely.

[0052] In Figure 8E, microcatheter 802 is advanced through artery A so that its distal tip passes through the clot and is distal to clot C. Guidewire GW may be retracted proximally and removed from the patient.

[0053] Once the microcatheter is positioned, a stent retriever catheter, such as any of those disclosed herein, may be introduced through a port in the introducer (not shown) at the vascular access point and advanced through the microcatheter toward the treatment area. An outer sheath (not shown) may be placed over the stent retriever catheter for packaging and shipping purposes and to constrain the expandable cage. Thus, once the stent retriever is inserted into the microcatheter, the outer sheath on the stent retriever may be retracted proximally and removed from the expandable cage. The microcatheter then constrains the expandable cage, preventing it from self-expanding.

[0054] 8F shows a clot retriever catheter 806 positioned within microcatheter 802 and traversing clot C. Shown is clot retrieval device 806 including a distal portion of an expandable cage traversing clot C, an expandable capture cage 804, an elongated shaft 810, an optional proximal radiopaque marker or collar 812, and an optional distal radiopaque marker or collar 808. Clot retriever catheter 806 may be any of the embodiments disclosed herein.

[0055] Microcatheter 802 not only provides a channel for delivery of clot retriever catheter 806, but also provides a restraint to hold expandable capture cage 804 in a collapsed configuration during delivery. Optional proximal and distal radiopaque markers 808, 812 allow the operator to visualize the location of the device and ensure that the expandable capture cage is positioned along the entire length of clot C. Extension shaft 810 is a guidewire coupled to the expandable capture cage, allowing the operator to push or pull the device along artery A, through the microcatheter, and against clot C. The expandable capture cage may include any or all permutations or combinations of the capture cage features described in any embodiment herein.

[0056] Once the capture cage 804 is properly positioned relative to the clot C, the microcatheter 802 is retracted proximally, as shown in FIG. 8G, while the clot retrieval catheter remains stationary or is advanced slightly out of the microcatheter. When the microcatheter 802 is removed from the expandable capture cage 804, it self-expands (814) to engage the clot C and the vessel wall. Because the walls of the capture cage are formed from closed cells, the cage walls are porous with openings extending through them creating a mesh-like cage wall, which can expand into the clot C and entangle it so that the clot is located inside the cage and the cage struts are outside or nearly outside the clot. FIG. 8G shows partial expansion of the distal portion of the cage extending beyond the clot.

[0057] In Figure 8H, further proximal retraction of the microcatheter 802 unsheathes the entire capture cage so that it may self-expand, engulfing the clot C and thereby integrating the clot with the expandable cage. The capture cage may self-expand to appose the wall of the vessel. The entire clot C is now substantially within the expanded capture cage 814.

[0058] FIG. 8I shows that once the cage 814 self-expands and entangles the clot C, the entire clot retrieval device 806 is proximally retracted by pulling the elongated shaft 810, which extends proximally outside the patient's body so that the operator can grasp and manipulate the proximal end. Proximal retraction of the catheter also carries the entangled clot C along with the cage 814 as it is retracted proximally. The catheter 806 and clot, along with the microcatheter 802, are then retracted proximally until they are removed from the patient. The expandable cage 814 may be retracted proximally so that the proximal end of the expandable cage approaches the distal end of the microcatheter, or the two ends may remain separate from one another. Both the microcatheter and the elongated shaft 810 of the clot retrieval catheter may be retracted proximally together or individually.

[0059] 8J shows an optional sheath S that may be used to aid in delivering a clot retrieval catheter (see FIG. 8D). After the clot is entrapped within the cage 814, the microcatheter and cage 814 may be retracted proximally into the sheath S, and the entirety removed from the patient. Alternatively, optionally, the microcatheter and cage 814 may be retracted proximally adjacent the distal end of the sheath S, but not necessarily all the way into the sheath S, and then the entirety removed from the patient.

[0060] 8K shows the artery after the clot, microcatheter, optional sheath, and clot removal device have been removed from artery A. Once the obstruction is removed, the blood vessel is now patent again and tissue downstream of the clot will now receive oxygenated blood.

[0061] The procedure is ideally performed as quickly as possible. In any embodiment, 5, 4, 3, 2, or 1 minute following expansion may be allowed for the clot to consolidate into the expanded cage before the device is retracted proximally to remove the clot.

[0062] The example method shown in Figures 8A-8K is illustrated with respect to clot removal from arteries in the brain during a stroke. However, this is not intended to be limiting, and the method may be applied to removing obstructions from other parts of the body, including clots or other vascular obstructions in other arteries of the body. In addition, the clot retrieval device shown in Figures 8A-8K may be any of the devices disclosed herein with any of the features used in any permutation or combination. Thus, any of the expandable cages may be used in conjunction with any of the features, such as radiopaque markers, lemon-shaped closed-cell geometry, flexible regions, dual struts, tapered or beveled proximal and distal ends, and any of the strut configurations.

[0063] 9 shows another example of an expandable cage that can be used with any of the clot retrieval catheters described herein. Here, the clot retrieval catheter shows only an expandable capture cage 900 having a proximal end P and a distal end D. The extension shaft is not shown in this figure, but it is generally identical to any of the other extension shafts that are coupled to the capture cages described herein, such as those in FIGS. 1, 2, 3B, 4A, 6B, 7, and 8A-8K above.

[0064] The example in FIG. 9 is an expandable cage 900 that has been unrolled and flattened along its longitudinal axis. The expandable cage is self-expanding and may be formed from any shape-memory or superelastic material, such as Nitinol. The expandable cage includes several regions along its longitudinal axis. Moving from the proximal end to the distal end, the expandable cage includes a single strut 902, a diamond-shaped closed-cell region 904, a lemon-shaped closed-cell region 906, and an intermediate region 908 with closed cells with multiple convex and concave contours that result in cells that may resemble peanuts or edamame pods. The next region has closed lemon-shaped cells 910, and the expandable cage terminates in a closed tapered porous tip region 912 formed from linear struts that converge to a point. Each region is bonded to the adjacent region. The entire cage may be laser cut or electrical discharge machined (EDM) from hypotubing or photoetched from a flat sheet of material, then rolled up, and the opposing edges welded together.

[0065] The single strut 902 has a generally rectangular cross-section (the inner and outer surfaces may be slightly arcuate due to the curvature of the hypotube from which it is cut), but any cross-section may be used, and the width and thickness may be modified to give the strut desired mechanical properties. The single strut may be wider / shorter or thicker / thinner than the struts in any of the other regions of the capture cage. The single strut 902 extends proximally and may be releasably or fixedly coupled to the distal end of an elongated shaft (not shown), such as a guidewire. The elongated shaft is then used to advance, retract, or otherwise manipulate the expandable cage position as it is delivered to the treatment site. Additional disclosure regarding how the single strut may be coupled to an elongated shaft is provided below.

[0066] The region of closed diamond cells 904 includes multiple rows of diamond cells, decreasing proximally until the last row has only a single diamond cell. This region of the capture cage helps provide the device with desired mechanical properties so that the capture cage has good extrusion and tracking ability to the vessel contours during delivery and deployment, or during retraction. The strength of the diamond-shaped closed cells also provides the desired strength to the capture cage in this region. In this example, the region includes three rows of diamond cells, followed by a row of two diamond cells, followed by a single diamond cell, from the distal end to the proximal end. The rows are circumferential, transverse to the longitudinal axis of the cage. Each diamond cell includes four linear struts 914, which are joined together to form the diamond-shaped closed cell. The strut width or thickness can be adjusted as needed to provide the desired mechanical properties. Thus, the struts in the diamond-shaped closed-cell region may be thicker or thinner, or wider or shorter, than the struts in other regions of the capture cage to prevent buckling of the capture cage when it is unsheathed from the microcatheter or sheath. When the diamond-shaped closed-cell region is rolled up into a cylindrical shape to form the capture cage, the open proximal end of the cage is created and has a beveled shape with gaps between opposing edges of the struts that decrease proximally. The beveled shape is substantially identical to that described above in the above examples. The tapered beveled shape helps align the proximal end of the cage with the sheath, ensuring that the cage can be easily retracted into the sheath (if used) without getting caught on the distal edge of the sheath. The angle between adjacent struts on the proximal and distal ends of the diamond-shaped cells increases as the expandable cage opens and decreases as the cage closes. The angle between adjacent struts at the top and bottom of the diamond-shaped cells decreases as the cage expands and increases as the cage collapses.

[0067] The lemon-shaped closed cell region 906 in this example includes a single circumferential ring (or row) of closed lemon-shaped cells. Each lemon-shaped cell is formed from four struts, which may be shared with adjacent cells. Here, the four struts include two linear struts 916, 918 joined together to form the proximal pointed portion of the lemon shape, an S-shaped strut 922 (S-shaped from distal to proximal transverse), and an inverted S-shaped strut 920 (distal to proximal). The S-shaped and inverted S-shaped struts are joined together to form the distal pointed portion of the lemon shape. Opposite ends of the S-shaped and inverted S-shaped struts are joined to opposite ends of the two linear struts to form the closed lemon-shaped cell. Thus, in this embodiment, the proximal end of the S-shaped strut is connected to the distal end of the upper linear strut to form the peak of the lemon-shaped cell, and the proximal end of the upper linear strut is connected to the proximal end of the lower linear strut to form the proximal pointed end of the lemon shape. The distal end of the lower linear strut is connected to the proximal end of the inverted S-shaped strut to form the valley of the lemon-shaped cell, and the distal end of the inverted shaped strut is connected to the distal end of the S-shaped strut to form the distal pointed end of the lemon shape. The S-shaped strut 922 has a distal concave region facing outward from the closed cell and a proximal concave region facing inward toward the closed cell. The inverted S-shaped strut 920 has a distal concave region facing outward away from the closed cell and a proximal concave region facing inward toward the closed cell. As illustrated in the lemon-shaped cells in the examples above or on the distal end of cage 900 as will be described below, the upper linear struts 916 may be replaced with inverted S-shaped struts and the lower linear struts 918 may be replaced with S-shaped struts. The linear struts, S-shaped struts, or inverted S-shaped struts may be wider / shorter or thicker / thinner than the struts in any of the other regions of the capture cage.

[0068] The intermediate region 908 of closed cells includes a plurality of closed rings extending circumferentially around the longitudinal axis of the expandable cage 900. Each ring includes a plurality of closed cells roughly shaped like a peanut or edamame pod. Each closed cell is formed from six struts, including two upper S-shaped struts, an upper inverted S-shaped strut, two lower S-shaped struts, and a lower inverted S-shaped strut, which are joined together to form the closed cell. The S-shaped and inverted S-shaped struts may be wider / shorter or thicker / thinner than the struts in any of the other regions of the capture cage.

[0069] Each lemon-shaped closed cell 908 is formed from a first S-shaped strut 928 (S-shaped from distal to proximal) connected to a second S-shaped strut 926 that is connected to the first inverted-S-shaped strut. The first inverted-S-shaped strut 924 is connected to a third S-shaped strut 930, which is connected to a fourth S-shaped strut 932, which is then connected to a second inverted-S-shaped strut 934. The second inverted-S-shaped strut 934 is connected to the first S-shaped strut 928. Thus, the proximal end of the first S-shaped strut 928 is connected to the distal end of the second S-shaped strut 926, forming a first apex region, and the proximal end of the second S-shaped strut 926 is connected to the distal end of the first inverted-S-shaped strut 924, forming a second, higher apex. The proximal end of the first inverted-S-shaped strut 924 is joined to the proximal end of the third S-shaped strut 930, forming the proximal, pointed region of the lemon-shaped cell, and the distal end of the third S-shaped strut 930 is joined to the proximal end of the fourth S-shaped strut 932, forming a slight first valley. The distal end of the fourth S-shaped strut 932 is joined to the proximal end of the second inverted-S-shaped strut 934, forming a second, deeper valley, and the distal end of the second inverted-S-shaped strut 934 is joined to the distal end of the first S-shaped strut 928, forming the distal, pointed portion of the lemon-shaped cell. The S-shaped struts 926, 928 on the upper portion of the lemon-shaped cell have distal portions with outward-facing concave regions and proximal portions with inward-facing concave regions. The upper inverted-S strut 924 has a distal portion with an inward-facing concave region and a proximal portion with an outward-facing concave region. The two lower S-shaped struts 930, 932 have distal portions with inward-facing concave regions and proximal portions with outward-facing concave regions. The lower inverted-S strut 934 has a distal portion with an outward-facing concave region and a proximal portion with an inward-facing concave region. Here, the middle region includes seven rows or closed rings of edamame-shaped closed cells, although this is not limiting and the number of cells may be increased or decreased to accommodate longer or shorter treatment regions.

[0070] Continuing distally along the capture cage 900, the next region includes a ring or row of lemon-shaped cells 910. Here, there is only a single ring of lemon-shaped cells, but this is not limiting and the number of rings or rows of lemon-shaped cells may be increased as needed. Here, the lemon-shaped cell differs slightly from the lemon-shaped cell 906 described above, because the cells 910 are formed from an upper S-shaped strut 938 connected to an upper inverted S-shaped strut 936 connected to a lower S-shaped strut 940 connected to a lower inverted S-shaped strut 942 connected to an upper S-shaped strut 938. The S-shaped and inverted S-shaped struts may be wider / shorter or thicker / thinner than the struts in any of the other regions of the capture cage. Thus, the proximal end of upper S-shaped strut 938 is joined to the distal end of upper inverted S-shaped strut 936 to form the peak, the proximal end of upper inverted S-shaped strut 936 is joined to the proximal end of lower S-shaped strut 940 to form the pointed proximal end of the lemon, the distal end of lower S-shaped strut 940 is joined to the proximal end of lower inverted S-shaped strut 942 to form the valley in the lemon shape, and the distal end of lower inverted S-shaped strut 942 is joined to the distal end of upper S-shaped strut 938 to form the pointed distal end of the lemon.

[0071] The proximal-most region of the expandable cage 900 is a closed porous conical or tapered tip 912 formed from a plurality of linear struts 944. Because FIG. 9 illustrates the capture cage in a flat, unrolled view, FIG. 9 shows the linear struts 944 extending horizontally and parallel to one another. The conical or tapered shape will be more apparent in subsequent figures. Here, the closed porous conical or tapered tip 912 is formed from four linear struts 944 having proximal and distal ends. The proximal ends of the linear struts 944 are joined to the distal, pointed ends of each lemon-shaped closed cell, and the linear struts extend distally. They extend radially inward to form the tapered or conical tip, and the distal ends of the linear struts converge to a point where they are joined together, as will be described in more detail below. The gaps between the linear struts create a porous tip 912, the gaps being small enough to prevent thrombus from escaping from the distal tip, but large enough to allow blood to flow through it and prevent ischemia caused by the clot retrieval device. The linear struts may be wider / shorter or thicker / thinner than the struts in any of the other regions of the capture cage.

[0072] 10A shows the expandable capture cage 900 from FIG. 9 coupled to an elongated shaft 1002, such as a guidewire. The expandable capture cage 900 is in an expanded configuration. Also, the closed tapered or conical distal tip 912 is more clearly visible in this view.

[0073] FIG. 10B shows the expandable capture cage 900 from FIG. 9 in a collapsed configuration. The conical distal tip 912 facilitates slidably advancing the capture cage into the lumen of the outer sheath 1002 (or microcatheter or any other tubing) so that the outer sheath constrains the capture cage in the collapsed configuration. The distal end of the conical distal tip 912 is shown with struts extending longitudinally and distally away from the conical distal tip. Optionally, radiopaque and / or atraumatic tips formed with coils may be coupled to the struts. The proximal single strut 902 may be coupled to an elongated shaft, such as a guidewire, as discussed above. When the outer sheath 1002 is removed from the capture cage, the capture cage will self-expand to its unbiased expanded configuration.

[0074] Figure 11 more clearly illustrates the closed tapered or conical distal porous tip 912 from Figures 9-10. Here, the lemon-shaped closed cells 910 are visible with pointed distal ends 914 to which linear struts 944 are joined. The linear struts 944 extend radially inward toward the centerline of the capture cage and converge to a point distally D, where the distal ends of the linear struts are joined to each other and form the tip. The gaps between the linear struts create porosity in the closed tapered distal tip, but the porosity is not so great as to allow clot material to escape from the distal porous tip, yet it is porous enough to allow blood to flow through it and prevent or avoid ischemia.

[0075] The four linear struts 944 in FIG. 11 converge to a point, which may be sharp. To avoid a sharp, traumatic tip, FIG. 12 shows how the distal end of the porous tip can optionally be finished. In FIG. 11, a filament 1102 is helically wound around the four linear struts 944 to create an atraumatic tip. The filament may be a metal wire, such as stainless steel or nitinol, and is helically wound around the four linear struts to prevent them from extending past the helical coil formed by the filament. The filament may then be welded, bonded, soldered, or otherwise attached to the four linear struts to hold the distal end in a secure configuration. The helical coil thus forms an atraumatic tip as well as provides a denser portion of the device at the distal end, which enhances the radiopacity of the distal tip so that the operator can visualize the device's position under fluoroscopy or other radiographic imaging. This optional distal tip may be used in any of the embodiments of the clot retrieval device disclosed herein.

[0076] FIG. 12B shows an end view of the distal tip of a tapered or conical distal tip in which four linear struts 944 are positioned below the helical coil 1102.

[0077] FIG. 12C shows a side view of the distal tip of a tapered or conical distal tip in which four linear struts 944 are positioned below the helical coil 1102.

[0078] 13A-13B show how the proximal end of the capture cage is coupled to the elongated shaft of the clot retrieval catheter.

[0079] 13A , a single linear strut 1302 extending proximally from the proximal end of the capture cage may be a flat, rectangular wire that tapers to a narrower, flat, rectangular wire 1304 that is positioned below a core wire 1306 of a guidewire coil 1308 when the elongated shaft of the clot retrieval catheter is a guidewire. Here, the core wire 1306 may have a square cross-section, although any cross-section may be used. A wire such as a filament, here stainless steel or any other material, is wound helically around the core wire to form the guidewire coil 1308. The area of ​​overlap between the capture cage's single strut 1304 and the guidewire core wire 1306 may be bonded, welded, soldered, or otherwise joined together, thereby securing the capture cage to the elongated shaft, here the guidewire. An additional optional filament 1310 may also be spirally wound from the capture cage around the proximal end of the single strut 1304 to create a radiopaque marker to help the operator visualize the proximal end of the capture cage under fluoroscopy or other radiological imaging.

[0080] Figure 13B shows a cross-section of the proximal end of the clot retrieval catheter taken along line AA in Figure 13A. Here, the overlap region between the capture cage's single strut 1304 and the guidewire core wire 1306 is clearly visible; this is where the two components may be joined, welded, or otherwise attached to one another. Also visible is an outer coil, which may be either a radiopaque coil 1310 or a guidewire coil 1308, depending on where the transition between the guidewire coil and the radiopaque coil exists. The attachment techniques and radiopaque marker features shown in Figures 13A-13B are optional and may be used in any embodiment of the clot retrieval catheter disclosed herein.

[0081] Use of the clot retrieval device illustrated in Figures 9-13B above is substantially identical to the method of use described in Figures 8A-8K above. Clot retrieval in the neurovasculature generally involves the capture of red or white clots. White clots are also known as fibrin-rich clots due to the concentration of fibrin in the clot, and red clots are also referred to as RBC-rich clots due to the concentration of red blood cells (RBCs) in the clot. While the device in any of the examples described herein may retrieve red clots as effectively as or more effectively than commercially available devices, the designs disclosed herein, including Figure 9, are believed, based on testing, to capture white clots more effectively than other commercially available clot retrieval devices. Without being bound by any particular theory, it is believed that the strut geometry allows for more effective retrieval of white clots compared to red clots. Thus, due to their shape and mechanical properties, the struts have a greater ability to entangle white clots, and the capture cage can then retain the white clots and remove them from the vessel. Strut width and shape may enable this clinical outcome. The design of Figure 9 has the geometry described above, and strut widths may range from about 0.0254 mm to about 0.1016 mm (about 0.001 inch to about 0.004 inch), or about 0.0508 mm to about 0.0889 mm (about 0.0020 inch to about 0.0035 inch), with thickness determined by the thickness of the hypotube from which the struts are cut. Thus, the post thickness may range from about 0.001 inch to about 0.005 inch, or from about 0.002 inch to about 0.004 inch, or from about 0.003 inch to about 0.0035 inch. In one embodiment, the nominal dimensions are about 0.0036 inch thick by about 0.0020 inch to about 0.0035 inch wide.9, the struts in the clot engaging section of the expandable cage may have a total strut contact area of ​​about 41.52 square millimeters (about 0.064357 square inches), so in the nominal case where the capture cage has a nominal 5 Newton radial force, the force per unit area would be about 5 Newtons per 41.52 square millimeters or 0.1204 Newtons per square millimeter. This calculation may be repeated for other ranges of radial forces disclosed herein.

[0082] The capture cage design also has a radial force (ability to resist crushing) of about 1-10 Newtons, or about 1-8 Newtons, or about 1-6 Newtons, or about 1-5 Newtons. In one embodiment, the nominal radial force is about 5 Newtons. The capture cage may have any number of struts extending circumferentially around the device; for example, in the embodiment of FIG. 9, the cage has 4-8 struts extending circumferentially around the capture cage, depending on longitudinal location; therefore, the radial force per strut ranges from about 1 Newton per 8 struts, or 0.125 Newtons per strut radial strength to about 1 Newton per 4 struts, or from 0.25 Newtons per strut radial strength at the low end of the range to about 10 Newtons per 8 struts at the high end of the range, or about 1.25 Newtons per strut radial strength to about 10 Newtons per 4 struts, or about 2.5 Newtons per strut radial strength. When the nominal radial strength is 5 Newtons, the radial strength per strut ranges from approximately 5 Newtons per 8 struts, or 0.625 Newtons per strut radial strength, to approximately 5 Newtons per 4 struts, or 1.25 Newtons per strut radial strength. Other radial strengths per strut number may also be calculated using any of the ranges of radial strength normalized with any of the strut ranges disclosed herein. These radial strengths per strut may be a factor in ensuring capture and removal of red blood cells and red clots as effectively as, or more effectively than, commercially available devices. However, given the cell geometry and mechanical properties of the present devices, including the radial strength per strut, the embodiments disclosed herein, including FIG. 9, are believed to be more effective at removing difficult-to-remove clots (such as white blood cells) when compared to commercially available devices.

[0083] Optionally, any embodiment of the clot retrieval device disclosed herein may also be used to deliver a therapeutic agent to the treatment site. For example, thrombolytic drugs such as streptokinase or urokinase may also be delivered by the device. Other therapeutic agents, such as blood thinners like heparin, may also be delivered to the treatment site by the clot retriever. Notes and Examples

[0084] The following non-limiting examples detail certain aspects of the present subject matter that, among other things, solve the problems and provide the benefits discussed herein.

[0085] Example 1 is a device for removing an obstruction from a blood vessel, the device comprising an elongated flexible shaft having a proximal end and a distal end, and an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage being coupled to the distal end of the elongated shaft, the expandable capture cage having a collapsed configuration and an expanded configuration, in the collapsed configuration the expandable capture cage is adapted to be delivered through the blood vessel, and in the expanded configuration the expandable capture cage is configured to expand into and engulf the obstruction so that the obstruction may be removed from the blood vessel by proximal retraction of the expandable capture cage.

[0086] Example 2 is the device of Example 1, where the obstruction is a thrombus.

[0087] Example 3 is the device of any of Examples 1-2, wherein the thrombus comprises a white clot or a red clot.

[0088] Example 4 is the device of any of Examples 1-3, wherein the elongate flexible shaft is a guidewire.

[0089] Example 5 is the device of any of Examples 1-4, wherein the expandable cage is self-expanding.

[0090] Example 6 is the device of any of Examples 1-5, wherein the proximal end of the expandable capture cage is open and comprises a proximal edge that is at an oblique angle relative to the longitudinal axis of the expandable capture cage.

[0091] Example 7 is the device of any of Examples 1-6, wherein the proximal end of the expandable capture cage comprises a plurality of open or closed rings, each open or closed ring in the plurality of open or closed rings comprising one or more closed cells, each open or closed ring having a total number of closed cells that decrease in the proximal direction until the most proximal ring is an open ring having a single closed cell.

[0092] Example 8 is a device described in any of Examples 1-7, wherein the proximal end of the expandable capture cage comprises a plurality of rings, at least some of the plurality of rings being open rings with gaps disposed between opposing edges of the open rings, the gaps increasing in the proximal direction.

[0093] Example 9 is a device described in any of Examples 1-8, wherein the expandable cage comprises a plurality of struts joined together, and at least some of the struts located on the proximal end of the expandable cage have a width or thickness that is less than some of the struts located distally thereof.

[0094] Example 10 is the device of any of Examples 1-9, wherein the expandable cage tapers from the proximal end of the expandable cage to the distal end of the expandable cage.

[0095] Example 11 is the device of any of Examples 1-10, wherein the expandable cage comprises a plurality of closed cells, and the plurality of closed cells has a lemon shape.

[0096] Example 12 is the device of any of Examples 1-11, wherein the closed cell comprises a tapered proximal end, a tapered distal end, an apex between the tapered proximal and distal ends, and a valley between the tapered proximal and distal ends.

[0097] Example 13 is the device of any of Examples 1-12, wherein the expandable cage comprises a plurality of closed cells, the plurality of closed cells comprising a plurality of concave contours and a plurality of convex contours.

[0098] Example 14 is the device of any of Examples 1-13, wherein some of the plurality of closed cells comprise six S-shaped or inverted S-shaped struts, a first S-shaped strut having a distal end with an outward-facing concave region and a proximal end with an inward-facing concave region, a second S-shaped strut having a distal end with an outward-facing concave region and a proximal end with an inward-facing concave region, and a third inverted S-shaped strut having an outward-facing concave region and a proximal end with an inward-facing concave region. a fourth S-shaped strut having a proximal end with an outward-facing concave region and a distal end with an inward-facing concave region; a fifth S-shaped strut having a proximal end with an outward-facing concave region and a distal end with an inward-facing concave region; and a seventh inverted S-shaped strut having a proximal end with an inward-facing concave region and a distal end with an outward-facing concave region.

[0099] Example 15 is the device of any of Examples 1-14, wherein the proximal end of the first S-shaped strut is coupled to the distal end of the second S-shaped strut, the proximal end of the second S-shaped strut is coupled to the distal end of the third inverted S-shaped strut, the proximal end of the third inverted S-shaped strut is coupled to the proximal end of the fourth S-shaped strut, the distal end of the fourth S-shaped strut is coupled to the proximal end of the fifth S-shaped strut, the distal end of the fifth S-shaped strut is coupled to the proximal end of the sixth inverted S-shaped strut, and the distal end of the sixth inverted S-shaped strut is coupled to the distal end of the first S-shaped strut.

[0100] Example 16 is the device of any of Examples 1-15, wherein the proximal end of the expandable cage comprises a plurality of lemon-shaped cells and a plurality of diamond-shaped cells.

[0101] Example 17 is the device of any of Examples 1-16, wherein the plurality of lemon-shaped cells comprises an S-shaped strut, a first linear strut, a second linear strut, and an inverted S-shaped strut, wherein the S-shaped strut is coupled to the first linear strut, the first linear strut is coupled to the second linear strut, the second linear strut is coupled to the inverted S-shaped strut, and the inverted S-shaped strut is coupled to the S-shaped strut.

[0102] Example 18 is the device of any of Examples 1-17, wherein the plurality of diamond-shaped cells comprises four linear posts joined together.

[0103] Example 19 is a device described in any of Examples 1-18, wherein the proximal end of the expandable cage comprises a decreasing number of diamond-shaped cells, and the last diamond-shaped cell in the decreasing number of diamond-shaped cells is coupled to the elongated shaft.

[0104] Example 20 is the device of any of Examples 1-19, wherein the proximal end of the expandable capture cage terminates in a single strut that overlaps and is coupled to the distal end of the elongate shaft.

[0105] Example 21 is the device of any of Examples 1-20, further comprising a filament helically disposed around the single strut and elongate shaft to form a flexible radiopaque joint.

[0106] Example 22 is the device of any of Examples 1-21, wherein the distal end of the expandable cage comprises a plurality of lemon-shaped closed cells, each lemon-shaped closed cell having a pointed distal region.

[0107] Example 23 is the device of any of Examples 1-22, wherein the lemon-shaped closed cell comprises four S-shaped or inverted S-shaped struts, wherein a first S-shaped strut has a distal end with an outward-facing concave region and a proximal end with an inward-facing concave region, a second inverted S-shaped strut has a distal end with an inward-facing concave region and a proximal end with an outward-facing concave region, a third S-shaped strut has a proximal end with an outward-facing concave region and a distal end with an inward-facing concave region, and a fourth inverted S-shaped strut has a proximal end with an inward-facing concave region and a distal end with an outward-facing concave region.

[0108] Example 24 is the device of any of Examples 1-23, wherein the proximal end of the first S-shaped strut is connected to the distal end of the second inverted S-shaped strut and forms a peak in the lemon-shaped closed cell; the proximal end of the second inverted S-shaped strut is connected to the proximal end of the third S-shaped strut and forms a pointed proximal end of the lemon-shaped closed cell; the distal end of the third S-shaped strut is connected to the proximal end of the fourth inverted S-shaped strut and forms a valley in the lemon-shaped closed cell; and the distal end of the fourth inverted S-shaped strut is connected to the distal end of the first S-shaped strut and forms a pointed distal end of the lemon-shaped closed cell.

[0109] Example 25 is the device of any of Examples 1-24, wherein the peaks of the closed cells are inwardly facing and concave, and the valleys of the closed cells are inwardly facing and concave.

[0110] Example 26 is the device of any of Examples 1-25, wherein the distal end of the expandable capture cage comprises a plurality of linear struts coupled to a pointed distal region of the plurality of lemon-shaped cells, the linear struts tapering distally to a point forming a closed porous tip configured to prevent passage of an obstruction therethrough.

[0111] Example 27 is the device of any of Examples 1-26, further comprising a helical coiled filament disposed around the linear strut and forming an atraumatic radiopaque tip.

[0112] Example 28 is a system for removing an obstruction from a blood vessel, the system comprising a device described in any of Examples 1-27 and a microcatheter slidably positioned over the device.

[0113] Example 29 is the system of Example 28, further comprising a sheath slidably disposed over the microcatheter.

[0114] Example 30 is a method for removing an obstruction from a blood vessel, the method including the steps of providing a clot retrieval catheter having an expandable capture cage coupled to an elongated flexible shaft, introducing the clot retrieval catheter into the blood vessel, advancing the expandable capture cage through the blood vessel to the obstruction, radially expanding the expandable capture cage to engage the obstruction, entangling the obstruction using the expandable capture cage, removing the obstruction from the blood vessel using the clot retrieval catheter, and removing the clot retrieval catheter from the blood vessel.

[0115] Example 31 is the method of example 30, in which advancing the expandable capture cage through the blood vessel includes advancing an elongated flexible shaft through the microcatheter.

[0116] Example 32 is a method described in any of Examples 30-31, wherein the step of advancing the expandable capture cage includes a step of advancing the expandable capture cage distal to the obstruction or a step of advancing a microcatheter distal to the obstruction.

[0117] Example 33 is the method of any of Examples 30-32, further comprising advancing a microcatheter over the guidewire and removing the guidewire from the patient before introducing the clot retrieval catheter into the blood vessel.

[0118] Example 34 is the method of any of Examples 30-33, wherein the obstruction comprises a thrombus.

[0119] Example 35 is the method of any of Examples 30-34, wherein the thrombus comprises a white clot or a red clot.

[0120] Example 36 is the method of any of Examples 30-35, wherein the blood vessel is an arterial blood vessel in the patient's head.

[0121] Example 37 is a method described in any of Examples 30-36, wherein the step of radially expanding the expandable capture cage includes the step of retracting the microcatheter proximally away from the expandable capture cage to remove the restraint therefrom.

[0122] Example 38 is the method of any of Examples 30-37, wherein radially expanding the expandable capture cage includes allowing the expandable capture cage to self-expand.

[0123] Example 39 is a method described in any of Examples 30-38, wherein the step of radially expanding the expandable capture cage includes the step of expanding a plurality of closed cells formed with a plurality of S-shaped and inverted S-shaped struts connected together.

[0124] Example 40 is the method of any of Examples 30-39, further comprising preventing the obstruction from exiting the distal end of the expandable capture cage to which the tapered tip is coupled.

[0125] Example 41 is the method of any of Examples 30-40, wherein removing the obstruction from the blood vessel includes proximally retracting the expandable capture cage.

[0126] Example 42 is the method of any of Examples 30-41, wherein the step of proximally retracting the expandable capture cage includes retracting a beveled proximal edge of the expandable capture cage toward the distal end of the microcatheter or sheath.

[0127] Example 43 is the method of any of Examples 30-42, further comprising visualizing the radiopaque markers on the expandable capture cage using fluoroscopy.

[0128] Example 44 is a device for removing an obstruction from a blood vessel, comprising an elongated flexible shaft having a proximal end and a distal end, and an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage being coupled to the distal end of the elongated shaft, the expandable capture cage having a collapsed configuration and an expanded configuration, wherein in the collapsed configuration the expandable capture cage is adapted to be delivered through the blood vessel, and in the expanded configuration the expandable capture cage is configured to expand into and engulf the obstruction.

[0129] Example 45 is the device of example 44, wherein the expandable cage is formed from a nickel-titanium alloy.

[0130] Example 46 is the device of any of Examples 44-45, wherein the distal end of the expandable capture cage is closed and comprises a distal tapered porous tip.

[0131] Example 47 is the device of any of Examples 44-46, wherein the distal tapered tip comprises a plurality of linear or arcuate struts extending from the distal end of the expandable cage and converging to a point.

[0132] Example 48 is a device described in any of Examples 44-47, wherein the expandable cage comprises a plurality of interconnected struts, and at least some of the plurality of linear or arcuate struts at the tapered tip are thinner than at least some of the plurality of interconnected struts in the expandable cage.

[0133] Example 49 is a device described in any of Examples 44-48, wherein the expandable cage comprises a plurality of closed cells having peaks, valleys, and pointed regions, and the plurality of linear or arcuate struts are coupled to either one of the peaks, one of the valleys, one of the pointed regions, or an area located between one of the peaks or valleys and one of the pointed regions.

[0134] Example 50 is a device described in any of Examples 44-49, wherein the plurality of linear struts comprises struts having a first length and struts having a second length longer than the first length, the struts with the first length being coupled to a pointed region and the struts of the second length being coupled to a peak or valley portion, thereby allowing the distal tapered tip to accommodate shortening of the expandable cage.

[0135] Example 51 is a device described in any of Examples 44-50, wherein the proximal end of the expandable capture cage comprises a plurality of struts that converge proximally to a linear strut that is coupled to the distal end of the elongated flexible shaft.

[0136] Example 52 is a device described in any of Examples 44-51, wherein the proximal end of the expandable capture cage comprises a plurality of rings, each ring in the plurality of rings comprising one or more closed cells, each ring having a total number of closed cells that decreases in the proximal direction until the most proximal ring is an open ring having a single closed cell.

[0137] Example 53 is a device described in any of Examples 44-52, further comprising a proximal radiopaque marker positioned adjacent to the proximal end of the expandable cage or a distal radiopaque marker positioned adjacent to the distal end of the expandable cage.

[0138] Example 54 is a device described in any of Examples 44-53, wherein the expandable cage comprises a plurality of closed cells, at least some of which are joined together while at least some of which are disconnected from adjacent closed cells, thereby forming gaps that create flexible regions in the expandable cage.

[0139] Example 55 is a device described in any of Examples 44-54, wherein the expandable cage comprises a plurality of struts connected together, and the expandable cage comprises one or more regions with two or more side-by-side struts extending parallel to each other.

[0140] Example 56 is a device described in any of Examples 44-55, wherein the expandable cage comprises a plurality of struts coupled together and further comprises one or more radiopaque markers coupled to one or more of the plurality of struts.

[0141] Example 57 is the device of any of Examples 44-56, further comprising an outer sheath or microcatheter disposed over the expandable cage, the outer sheath or microcatheter restraining the expandable cage and holding it in the collapsed configuration.

[0142] Example 58 is the device of any of Examples 44-57, wherein the proximal ends of at least some of the plurality of closed cells comprise struts that are thicker than adjacent struts in at least some of the plurality of closed cells.

[0143] Example 59 is a device described in any of Examples 44-58, wherein some of the plurality of closed cells include four S-shaped or inverted S-shaped struts, wherein a first S-shaped strut has a proximal end with an outward-facing concave region and a distal end with an inward-facing concave region, a second inverted S-shaped strut has a proximal end with an inward-facing concave region and a distal end with an outward-facing concave region, a third S-shaped strut has a distal end with an outward-facing concave region and a proximal end with an inward-facing concave region, and a fourth inverted S-shaped strut has a distal end with an inward-facing concave region and a proximal end with an outward-facing concave region.

[0144] Example 60 is a device described in any of Examples 44-59, wherein the distal end of the first S-shaped strut is connected to the proximal end of the second inverted S-shaped strut to form an apex in the closed cell, the distal end of the second inverted S-shaped strut is connected to the distal end of the third S-shaped strut to form a pointed distal end of the closed cell, the proximal end of the third S-shaped strut is connected to the distal end of the fourth inverted S-shaped strut to form a valley in the closed cell, and the proximal end of the fourth inverted S-shaped strut is connected to the proximal end of the first S-shaped strut to form a pointed proximal end of the closed cell.

[0145] Example 61 is the device of any of Examples 44-60, wherein the peaks of the closed cells are inwardly facing and concave, and the valleys of the closed cells are inwardly facing and concave.

[0146] Example 62 is a system for removing an obstruction from a blood vessel, the system comprising: a clot retrieval catheter comprising an expandable capture cage coupled to an elongated flexible shaft, the expandable capture cage having a collapsed configuration and an expanded configuration, wherein in the collapsed configuration the expandable capture cage is adapted to be delivered through the blood vessel and in the expanded configuration the expandable capture cage is configured to expand into and entangle the obstruction; and a microcatheter having a lumen sized to slidably receive the clot retrieval catheter.

[0147] Example 63 is the system of Example 62, further comprising a sheath slidably disposed over the expandable capture cage.

[0148] In Example 64, the device, system, or method described in any one or any combination of Examples 1-63 can be optionally configured so that all of the listed elements or options can be used or selected.

[0149] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. The inventors also contemplate examples using any combination or permutation of those elements (or one or more aspects thereof) shown or described, either with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0150] In the event of inconsistency in usage between this document and any document so incorporated by reference, the usage in this document shall prevail.

[0151] As used herein, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, regardless of any other instance or usage of "at least one" or "one or more." As used herein, the term "or," unless otherwise indicated, is used to refer to non-exclusiveness, or "A or B" to include "A but not B," "B but not A," and "A and B." As used herein, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formulations, or processes that include elements in addition to those listed after such terms in a claim are still deemed to fall within the scope of that claim. Also, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0152] The above description is intended to be illustrative, not limiting. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be utilized, such as by those skilled in the art, upon review of the above description. The Abstract is provided to enable the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are incorporated herein as examples or embodiments into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.

Claims

1. 1. A device for removing an obstruction from a blood vessel, said device comprising: an elongate flexible shaft having a proximal end and a distal end; an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage coupled to the distal end of the elongated shaft; Equipped with the expandable capture cage comprises a region of closed diamond-shaped cells followed by a region of closed lemon-shaped cells followed by a middle region with closed peanut-shaped cells followed by a region of closed lemon-shaped cells, terminating in a closed tapered porous tip; the expandable capture cage has a collapsed configuration and an expanded configuration; In the collapsed configuration, the expandable capture cage is adapted to be delivered through the blood vessel; In the expanded configuration, the expandable capture cage is configured to expand into and engulf the obstruction such that the obstruction can be removed from the vessel by proximal retraction of the expandable capture cage.

2. The device of claim 1 , wherein the obstruction is a thrombus.

3. The device of claim 2 , wherein the thrombus comprises a white clot or a red clot.

4. The device of claim 1 , wherein the elongate flexible shaft is a guidewire.

5. The device of claim 1 , wherein the expandable cage is self-expanding.

6. The device of claim 1 , wherein the proximal end of the expandable capture cage is open and includes a proximal edge that is at an oblique angle relative to a longitudinal axis of the expandable capture cage.

7. 2. The device of claim 1, wherein the proximal end of the expandable capture cage comprises a plurality of open or closed rings, each open or closed ring in the plurality of open or closed rings comprising one or more closed cells, each open or closed ring having a total number of closed cells that decreases in the proximal direction until the most proximal ring is an open ring having a single closed cell.

8. 10. The device of claim 1, wherein the proximal end of the expandable capture cage comprises a plurality of rings, at least some of the plurality of rings being open rings with gaps disposed between opposing edges of the open rings, the gaps increasing in a proximal direction.

9. A device for removing an obstruction from a blood vessel, said device comprising: an elongate flexible shaft having a proximal end and a distal end; an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage coupled to the distal end of the elongated shaft; Equipped with the expandable capture cage has a collapsed configuration and an expanded configuration; In the collapsed configuration, the expandable capture cage is adapted to be delivered through the blood vessel; In the expanded configuration, the expandable capture cage is configured to expand into and engulf the obstruction such that the obstruction may be removed from the vessel by proximal retraction of the expandable capture cage; A device wherein the expandable cage comprises a plurality of struts coupled together, at least some of the struts located on a proximal end of the expandable cage having a width or thickness that is less than some of the struts located distally thereof.

10. The device of claim 1 , wherein the expandable cage tapers from a proximal end of the expandable cage to a distal end of the expandable cage.

11. 10. The device of claim 1, wherein the closed peanut-shaped cell comprises a tapered proximal end, a tapered distal end, an apex between the tapered proximal end and the tapered distal end, and a valley between the tapered proximal end and the tapered distal end.

12. The device of claim 1 , wherein the expandable cage comprises a plurality of closed cells, the plurality of closed cells comprising a plurality of concave contours and a plurality of convex contours.

13. some of the closed peanut-shaped cells include six S-shaped or inverted S-shaped struts; the first S-shaped strut has a distal end with an outwardly facing concave region and a proximal end with an inwardly facing concave region; the second S-shaped strut has a distal end with an outwardly facing concave region and a proximal end with an inwardly facing concave region; a third inverted-S strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; a fourth S-shaped strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; a fifth S-shaped strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; The device of claim 1 , wherein the sixth inverted-S-shaped strut has a proximal end with an inwardly facing concave region and a distal end with an outwardly facing concave region.

14. a proximal end of the first S-shaped strut coupled to a distal end of the second S-shaped strut; a proximal end of the second S-shaped strut is coupled to a distal end of the third inverted S-shaped strut; a proximal end of the third inverted-S strut coupled to a proximal end of the fourth inverted-S strut; a distal end of the fourth S-shaped strut coupled to a proximal end of the fifth S-shaped strut; a distal end of the fifth S-shaped strut is coupled to a proximal end of the sixth inverted S-shaped strut; 14. The device of claim 13, wherein a distal end of the sixth inverted-S strut is coupled to a distal end of the first S strut.

15. A device for removing an obstruction from a blood vessel, said device comprising: an elongate flexible shaft having a proximal end and a distal end; an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage coupled to the distal end of the elongated shaft; Equipped with the expandable capture cage has a collapsed configuration and an expanded configuration; In the collapsed configuration, the expandable capture cage is adapted to be delivered through the blood vessel; In the expanded configuration, the expandable capture cage is configured to expand into and engulf the obstruction such that the obstruction may be removed from the vessel by proximal retraction of the expandable capture cage; the expandable cage comprises a plurality of closed cells, the plurality of closed cells comprising a plurality of concave contours and a plurality of convex contours; A device wherein the proximal end of the expandable cage comprises a plurality of lemon-shaped cells and a plurality of diamond-shaped cells.

16. 16. The device of claim 15, wherein the plurality of lemon-shaped cells comprises an S-shaped strut, a first linear strut, a second linear strut, and an inverted S-shaped strut, the S-shaped strut being coupled to the first linear strut, the first linear strut being coupled to the second linear strut, the second linear strut being coupled to the inverted S-shaped strut, and the inverted S-shaped strut being coupled to the S-shaped strut.

17. 16. The device of claim 15, wherein the plurality of diamond-shaped cells comprises four linear struts joined together.

18. 16. The device of claim 15, wherein the proximal end of the expandable cage comprises a decreasing number of diamond-shaped cells, the last diamond-shaped cell in the decreasing number of diamond-shaped cells being coupled with the elongated shaft.

19. A device for removing an obstruction from a blood vessel, said device comprising: an elongate flexible shaft having a proximal end and a distal end; an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage coupled to the distal end of the elongated shaft; Equipped with the expandable capture cage has a collapsed configuration and an expanded configuration; In the collapsed configuration, the expandable capture cage is adapted to be delivered through the blood vessel; In the expanded configuration, the expandable capture cage is configured to expand into and engulf the obstruction such that the obstruction may be removed from the vessel by proximal retraction of the expandable capture cage; A device wherein the proximal end of the expandable capture cage terminates in a single strut that overlaps and is coupled to the distal end of the elongate shaft.

20. 20. The device of claim 19, further comprising a filament helically disposed around the single strut and the elongate shaft to form a flexible radiopaque joint.

21. 20. The device of claim 19, wherein the distal end of the expandable cage comprises a plurality of lemon-shaped closed cells, each lemon-shaped closed cell having a pointed distal region.

22. the plurality of lemon-shaped closed cells each having four S-shaped or inverted S-shaped struts; the first S-shaped strut has a distal end with an outwardly facing concave region and a proximal end with an inwardly facing concave region; a second inverted-S strut having a distal end with an inwardly facing concave region and a proximal end with an outwardly facing concave region; a third S-shaped strut having a proximal end with an outwardly facing concave region and a distal end with an inwardly facing concave region; 22. The device of claim 21, wherein the fourth inverted S-shaped strut has a proximal end with an inwardly facing concave region and a distal end with an outwardly facing concave region.

23. a proximal end of the first S-shaped strut is connected to a distal end of the second inverted S-shaped strut to form an apex in the lemon-shaped closed cell; a proximal end of the second inverted S-shaped strut is joined to a proximal end of the third S-shaped strut to form a pointed proximal end of the lemon-shaped closed cell; a distal end of the third S-shaped strut is connected to a proximal end of the fourth inverted S-shaped strut to form a valley in the lemon-shaped closed cell; 23. The device of claim 22, wherein a distal end of the fourth inverted S-shaped strut is joined to a distal end of the first S-shaped strut to form a pointed distal end of the lemon-shaped closed cell.

24. 24. The device of claim 23, wherein the peaks of the closed cells are inwardly facing and concave, and the valleys of the closed cells are inwardly facing and concave.

25. 22. The device of claim 21, wherein the distal end of the expandable capture cage comprises a plurality of linear struts coupled to pointed distal regions of the plurality of lemon-shaped cells, the linear struts tapering distally to a point to form a closed porous tip configured to prevent the obstruction from passing therethrough.

26. A device for removing an obstruction from a blood vessel, said device comprising: an elongate flexible shaft having a proximal end and a distal end; an expandable capture cage having a proximal end and a distal end, the proximal end of the capture cage coupled to the distal end of the elongated shaft; Equipped with the expandable capture cage has a collapsed configuration and an expanded configuration; In the collapsed configuration, the expandable capture cage is adapted to be delivered through the blood vessel; In the expanded configuration, the expandable capture cage is configured to expand into and engulf the obstruction such that the obstruction may be removed from the vessel by proximal retraction of the expandable capture cage; the expandable cage comprises a plurality of closed cells, the plurality of closed cells comprising a plurality of concave contours and a plurality of convex contours; the distal end of the expandable cage comprises a plurality of lemon-shaped closed cells, each lemon-shaped closed cell having a pointed distal region; a distal end of the expandable capture cage comprising a plurality of linear struts coupled to pointed distal regions of the plurality of lemon-shaped cells, the linear struts tapering distally to a point to form a closed porous tip configured to prevent passage of the obstruction therethrough; The device further comprises a helically coiled filament disposed around said linear strut and forming an atraumatic radiopaque tip.

27. 1. A system for removing an obstruction from a blood vessel, the system comprising: A device according to claim 1; a microcatheter slidably positioned over the device; A system comprising:

28. 28. The system of claim 27, further comprising a sheath slidably disposed over the microcatheter.

Images