The present technology generally relates to medical devices, and in particular, to occlusive devices for treating vascular defects.
Intracranial saccular aneurysms occur in 1% to 2% of the general population and account for approximately 80% to 85% of non-traumatic subarachnoid hemorrhages. Recent studies show a case fatality rate of 8.3% to 66.7% in patients with subarachnoid hemorrhage. Endovascular treatment of intracranial aneurysms with coil embolization involves packing the aneurysm sac with metal coils to reduce or disrupt the flow of blood into the aneurysm, thereby enabling a local thrombus or clot to form which fills and ultimately closes off the aneurysm. Although coiling has proven to have better outcomes than surgical clipping for both ruptured and unruptured aneurysms, treating complex aneurysms using conventional coiling is challenging. This is especially true for wide-necked aneurysms because coil segments may protrude from the aneurysm sac through the neck of the aneurysm and into the parent vessel, causing serious complications for the patient.
To address this, some treatments include temporarily positioning a balloon within the parent vessel across the neck of the aneurysm to prevent the coils from migrating across the neck during delivery. Alternatively, some treatments include permanently positioning a neck-bridging stent within the parent vessel across the neck of the aneurysm to prevent the coils from migrating across the neck during delivery. While balloon-assisted or stent-assisted coiling for wide-necked aneurysms has shown better occlusion rates and lower recurrence than coiling alone, the recanalization rate of treated large/giant aneurysms can be as high as 18.2%. Moreover, the addition of a balloon or stent and its associated delivery system to the procedure increases the time, cost, and complexity of treatment. Deployment of the stent or balloon during the procedure also greatly increases the risk of an intraprocedural clot forming, and can damage the endothelial lining of the vessel wall. Permanently positioning a stent within the parent vessel increases the chronic risk of clot formation on the stent itself and associated ischemic complications, and thus necessitates the use of dual antiplatelet therapy (“DAPT”). DAPT, in turn, increases the risk and severity of hemorrhagic complications in patients with acutely ruptured aneurysms or other hemorrhagic risks. Thus, neck-bridging stents are not indicated for the treatment of ruptured aneurysms.
The above-noted drawbacks associated with balloon- and stent-assisted coiling techniques influenced the development of intraluminal flow diverting stents, or stent-like structures implanted in the parent vessel across the neck of the aneurysm that redirect blood flow away from the aneurysm, thereby promoting aneurysm thrombosis. Flow diverters have been successfully used for treating wide-necked, giant, fusiform, and blister-like aneurysms. However, because they are positioned in the parent vessel, conventional flow diverters require DAPT to avoid clot formation on the stent itself and ischemic complications. This, in turn, increases the risk and severity of hemorrhagic complications in patients with acutely ruptured aneurysms or other hemorrhagic risks. Thus, flow diverters are not indicated for the treatment of ruptured aneurysms. Flow diverters have also shown limited efficacy in treating bifurcation aneurysms (35-50%).
Endosaccular flow disrupting devices have the potential to provide the intra-aneurysmal flow disruption of coiling with the definitive remodeling at the aneurysm-parent vessel interface achieved by intraluminal flow diverters. Endosaccular devices can be mesh devices configured to be deployed completely within the aneurysm sac, with the interstices of the mesh covering the aneurysm neck and reconstructing the aneurysm-parent vessel interface. The implant disrupts the blood flow entering and exiting the aneurysm sac (resulting in stasis and thrombosis) and supports neoendothelial overgrowth without requiring DAPT (unlike endoluminal flow diverters). Thus, endosaccular devices can be used to treat wide-necked aneurysms and ruptured aneurysms. Moreover, because the device is placed completely within the aneurysm sac, the parent and branch vessels are unimpeded and can be accessed for any further retreatment or subsequent deployment of adjunctive devices during treatment.
Accordingly, there is a need for improved devices, systems, and methods for treating aneurysms and other vascular defects.
The subject technology is illustrated, for example, according to various aspects described below. These are provided as examples and do not limit the subject technology.
Clause 1. An occlusive device for treating an aneurysm, the occlusive device expandable from a low-profile configuration to an expanded configuration, the occlusive device comprising: an anchor structure extending circumferentially around an opening; a plurality of spiral struts coupled to the anchor structure and extending over the opening; and a plurality of protrusions extending away from the spiral struts, wherein the plurality of spiral struts and protrusions are arranged within a common plane when the occlusive device is in the expanded configuration, and wherein, when the occlusive device is deployed within the aneurysm in the expanded configuration, the plurality of spiral struts span a neck of the aneurysm and the anchor structure engages a wall of the aneurysm near the neck.
Clause 2. The occlusive device of any one of the preceding clauses, wherein the protrusions each have a first end coupled to a respective spiral strut and a second free end.
Clause 3. The occlusive device of any one of the preceding clauses, wherein the protrusions each have a first end coupled to a first spiral strut and a second end coupled to a second spiral strut.
Clause 4. The occlusive device of any one of the preceding clauses, wherein the device is laser-cut or etched from a single flat sheet of material.
Clause 5. The occlusive device of any one of the preceding clauses, wherein the anchor structure comprises a ring-shaped frame that, in the expanded configuration, extends away from the common plane.
Clause 6. The occlusive device of any one of the preceding clauses, wherein the anchor structure extends substantially perpendicular to the common plane.
Clause 7. The occlusive device of any one of the preceding clauses, further comprising a hub, wherein each spiral strut includes a first end region coupled to the hub, and a second end region coupled to the anchor structure.
Clause 8. The occlusive device of any one of the preceding clauses, wherein the second end region of each spiral strut is coupled to a peripheral edge of the anchor structure.
Clause 9. The occlusive device of any one of the preceding clauses, wherein the second end regions of the plurality of spiral struts are spaced apart along the peripheral edge of the anchor structure.
Clause 10. The occlusive device of any one of the preceding clauses, further comprising a detachment element configured to releasably couple the anchor structure and the plurality of spiral struts to a pusher member.
Clause 11. The occlusive device of any one of the preceding clauses, further comprising a hub, wherein the detachment element is coupled to the plurality of spiral struts via the hub.
Clause 12. The occlusive device of any one of the preceding clauses, further comprising an elongate member connecting the detachment element to the hub.
Clause 13. The occlusive device of any one of the preceding clauses, wherein the anchor structure comprises a stent including a plurality of cells.
Clause 14. The occlusive device of any one of the preceding clauses, wherein, when the occlusive device is deployed within the aneurysm, the plurality of spiral struts are contained entirely within the aneurysm.
Clause 15. The occlusive device of any one of the preceding clauses, wherein, when the occlusive device is deployed within the aneurysm, the plurality of spiral struts are configured to exert outwardly directed forces to enhance the engagement between the anchor structure and the wall of the aneurysm.
Clause 16. The occlusive device of any one of the preceding clauses, wherein the anchor structure is integrally formed with the plurality of spiral struts and protrusions as a single unitary component.
Clause 17. An occlusive device for treating an aneurysm, the occlusive device comprising: an anchor structure defining a central opening; a hub; and a plurality of curved struts arranged in a spiral configuration, each of the curved struts having a first end region coupled to the anchor structure and a second end region coupled to the hub such that the plurality of curved struts extend over the central opening when the occlusive device is in a deployed configuration, each of the curved struts having a plurality of protrusions coupled thereto.
Clause 18. The occlusive device of any one of the preceding clauses, wherein, in the deployed configuration, the curved struts and the protrusions are arranged in a common plane.
Clause 19. The occlusive device of any one of the preceding clauses, wherein the anchor structure extends substantially perpendicular to the common plane.
Clause 20. The occlusive device of any one of the preceding clauses, wherein the anchor structure comprises a ring-shaped frame that, in the deployed configuration, extends away from the common plane.
Clause 21. The occlusive device of any one of the preceding clauses, wherein the protrusions each have a first end coupled to a respective curved strut and a second free end.
Clause 22. The occlusive device of any one of the preceding clauses, wherein the protrusions each have a first end coupled to a first curved strut and a second end coupled to a second curved strut.
Clause 23. The occlusive device of any one of the preceding clauses, wherein the device is laser-cut or etched from a single flat sheet of material.
Clause 24. The occlusive device of any one of the preceding clauses, further comprising a hub, wherein each curved strut includes a first end region coupled to the hub, and a second end region coupled to the anchor structure.
Clause 25. The occlusive device of any one of the preceding clauses, wherein the second end region of each curved strut is coupled to a peripheral edge of the anchor structure.
Clause 26. The occlusive device of any one of the preceding clauses, wherein the second end regions of the plurality of curved struts are spaced apart along the peripheral edge of the anchor structure.
Clause 27. The occlusive device of any one of the preceding clauses, further comprising a detachment element configured to releasably couple the anchor structure and the plurality of curved struts to a pusher member.
Clause 28. The occlusive device of any one of the preceding clauses, wherein the detachment element is coupled to the plurality of curved struts via the hub.
Clause 29. The occlusive device of any one of the preceding clauses, further comprising an elongate member connecting the detachment element to the hub.
Clause 30. The occlusive device of any one of the preceding clauses, wherein the anchor structure comprises a stent including a plurality of cells.
Clause 31. The occlusive device of any one of the preceding clauses, wherein, when the occlusive device is deployed within the aneurysm, the plurality of spiral struts are contained entirely within the aneurysm.
Clause 32. The occlusive device of any one of the preceding clauses, wherein, when the occlusive device is deployed within the aneurysm, the plurality of spiral struts are configured to exert outwardly directed forces to enhance the engagement between the anchor structure and a wall of the aneurysm.
Clause 33. The occlusive device of any one of the preceding clauses, wherein the anchor structure is integrally formed with the plurality of curved struts and protrusions as a single unitary component.
Clause 34. A method of treating an aneurysm, the method comprising: introducing an occlusive device at least partially into the aneurysm, wherein the occlusive device comprises an anchor structure coupled to a plurality of spiral struts, each of the spiral struts having at least one protrusion extending therefrom; and expanding the occlusive device such that the plurality of spiral struts extend across a neck of the aneurysm and the anchor structure engages a wall of the aneurysm near the neck.
Clause 35. The method of any one of the preceding clauses, wherein the occlusive device is introduced to the aneurysm via a catheter.
Clause 36. The method of any one of the preceding clauses, wherein the occlusive device is disposed within the catheter in a low-profile configuration, and wherein expanding the occlusive device comprises advancing the occlusive device out of the catheter such that the occlusive device self-expands into an expanded configuration.
Clause 37. The method of any one of the preceding clauses, wherein, when the occlusive device is in the expanded configuration, the plurality of spiral struts lie substantially within a single plane.
Clause 38. The method of any one of the preceding clauses, wherein, when the occlusive device is in the expanded configuration, the plurality of spiral struts conform to a diameter of the neck of the aneurysm.
Clause 39. The method of any one of the preceding clauses, further comprising:
introducing a conduit into the aneurysm, and delivering an embolization element into the aneurysm via the conduit.
Clause 40. The method of any one of the preceding clauses, further comprising retaining the embolization element within the aneurysm via the occlusive device.
Additional features and advantages of the present technology will be set forth in the description below, and in part will be apparent from the description, or may be learned by practice of the present technology. The advantages of the present technology will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.
The present technology relates to devices for treating vascular defects such as aneurysms, and associated systems and methods. In some embodiments, for example, an occlusive device for treating an aneurysm includes an anchor structure (e.g., a tubular or ring-shaped stent or braid) extending circumferentially around an opening. The occlusive device can also include a plurality of spiral struts coupled to the anchor structure and extending over the opening. When the occlusive device is deployed within the aneurysm, the anchor structure and the plurality of spiral struts can self-expand such that the plurality of spiral struts span a neck of the aneurysm and the mesh surface of the anchor structure engages a wall of the aneurysm near the neck. In some embodiments, the occlusive device further includes a plurality of protrusions that extend away from the spiral struts. When the device is in an expanded configuration, the protrusions and spiral struts can be arranged in a common plane. When deployed within an aneurysm, the spiral struts and protrusions can span the neck of the aneurysm, thereby obstructing the flow of blood (or embolic material such as coils, liquid embolics, etc.) into or out of the aneurysm.
The occlusive devices of the present technology can provide many advantages compared to conventional device for treating an aneurysm. For example, the use of spiral struts enables the occlusive device to expand outward to conform to different neck geometries, while keeping the struts substantially in-plane with the aneurysm neck and/or out of the parent vessel. Accordingly, the occlusive devices disclosed herein can be used to treat a wider range of aneurysm sizes (e.g., aneurysms having a neck diameter from 3 mm to 5 mm) and/or shapes (e.g., aneurysm necks having a non-circular shape, such as oblong or peanut-shaped), as well as challenging aneurysm types such as wide-necked aneurysms (e.g., aneurysms having a neck diameter greater than 4 mm and/or a dome-to-neck ratio less than 2). Additionally, the spiral struts can brace the anchor structure radially outward against the wall of the aneurysm near the neck, thus reducing the likelihood of the device becoming dislodged and/or prolapsing into the parent vessel. Moreover, the addition of protrusions extending away from the spiral struts within the common plane can increase the coverage area over the neck of the aneurysm, thereby increasing the occlusive effect of the implanted device. Once deployed, the devices herein can be contained partially or entirely within the aneurysm sac with little or no protrusion into the parent vessel, thus reducing the likelihood of clot formation and/or avoiding the need for concomitant DAPT.
Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings in which like numerals represent like elements throughout the several figures, and in which example embodiments are shown. Embodiments of the claims may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples.
As used herein, the terms “vertical,” “lateral,” “upper,” and “lower” can refer to relative directions or positions of features of the embodiments disclosed herein in view of the orientation shown in the Figures. For example, “upper” or “uppermost” can refer to a feature positioned closer to the top of a page than another feature. These terms, however, should be construed broadly to include embodiments having other orientations, such as inverted or inclined orientations where top/bottom, over/under, above/below, up/down, and left/right can be interchanged depending on the orientation.
The device 100 includes an anchor structure 102 coupled to a plurality of curved struts 104. The anchor structure 102 is configured to anchor the device 100 at or near the neck of the aneurysm, while the curved struts 104 are configured to retain an embolization element within the device 100, as described in further detail below. The anchor structure 102 includes a proximal end portion 106, a distal end portion 108, and a mesh surface 110 extending between the proximal end portion 106 and distal end portion 108. In some embodiments, the proximal end portion 106 and distal end portion 108 each have a respective opening, such that the anchor structure 102 includes a lumen extending between the proximal end portion 106 and distal end portion 108, and surrounded by the mesh surface 110. The length L of the anchor structure 102 (e.g., as measured from the proximal end portion 106 to the distal end portion 108 when the device 100 is fully expanded) can be no more than 4 mm, 3.5 mm, 3 mm, 2.5 mm, 2 mm, 1.5 mm, or 1 mm. The width W or diameter of the anchor structure 102 (e.g., as measured when the device 100 is fully expanded) can be at least 5 mm, 4.5 mm, 4 mm, 3.5 mm, 3 mm, 2.5 mm, 2 mm, 1.5 mm, or 1 mm. Although
In the embodiment of
The curved struts 104 are connected to the proximal end portion 106 of the anchor structure 102. As best seen in
In some embodiments, each curved strut 104 includes a first end region 116 (e.g., a proximal end region) coupled to a hub 120 and a second end region 118 (e.g., a distal end region) coupled to the proximal end portion 106 of the anchor structure 102. The second end region 118 of each curved strut 104 can be coupled to a proximal apex 119 of a respective cell 114 of the anchor structure 102. In other embodiments, however, the second end region 118 can be coupled to a different portion of the cell 114, such as to a lateral edge of the cell 114. The hub 120 can be generally aligned with the center of the opening of the proximal end portion 106, and the second end regions 118 of the curved struts 104 can be spaced apart along the peripheral edge of the proximal end portion 106, such the separation distance between the curved struts 104 increases as the curved struts 104 radiate outward from the hub 120. The spacing between the curved struts 104 can be sufficiently large to permit an embolization element delivery device (e.g., a microcatheter or other elongate shaft) to pass through, but sufficiently small such that the embolization element does not prolapse into the parent vessel. In some embodiments, the average and/or maximum distance between neighboring curved struts 104 is no more than 2.5 mm, 2.25 mm, 2 mm, 1.75 mm, 1.5 mm, 1.25 mm, 1 mm, 0.75 mm, or 0.5 mm.
The configuration of the curved struts 104 can be varied in many different ways. For example, although
Referring to
In the illustrated embodiment, the hub 120 is a collar, band, ring, etc., that crimps or otherwise holds the first end regions 116 of the curved struts 104 together. Alternatively, the hub 120 can simply be the location where the first end regions 116 are connected to each other (e.g., via welding, bonding, adhesives, or may comprise a contiguous part of the flat sheet of material from which the device is laser-cut or etched, preferably forming a ring), rather than a separate component. As best seen in
Optionally, the device 100 can include one or more radiopaque portions so the physician can visualize the location and configuration of the device 100 during deployment in the aneurysm. For example, radiopaque markers (not shown) can be incorporated into the device 100 at or near the distal apices 115, at or near the proximal apices 119, at or near the intersections of adjacent cells 114, at or near the second end regions 118 of the curved struts 104, at or near the first end regions 116 of the curved struts 104, and/or on or within the hub 120.
The device 100 can be manufactured in many different ways. For example, the anchor structure 102 and/or curved struts 104 can be formed by laser-cutting of a tube or sheet, etching, metal injection molding, braiding, or any other suitable manufacturing process. In some examples, the device is formed by laser-cutting a flat sheet, which is then heat set in a desired configuration, for example with the anchor structure 102 extending approximately perpendicular upwardly from the plane of the sheet in which the curved struts 104 lie. Optionally, components of device cut from a single flat sheet can be welded or otherwise joined together after or in combination with being heat set into a desired configuration.
In some embodiments, the anchor structure 102 and curved struts 104 are integrally formed as a single unitary component. In other embodiments, the anchor structure 102 and curved struts 104 can be discrete components that are attached to each other, e.g., using welding, adhesives, fasteners, or other suitable techniques. The anchor structure 102 and/or curved struts 104 can be formed of known flexible materials, including shape memory and/or superelastic materials (e.g., Nitinol), cobalt chromium, platinum, stainless steel, other metals or metal alloys, or a combination thereof. Optionally, portions of the anchor structure 102 and/or curved struts 104, or the entirety of the anchor structure 102 and/or curved struts 104, can include one or more coatings or surface treatments, such as coatings or treatments to increase lubricity and/or reduce the delivery force as the device 100 is advanced through the delivery catheter, increase hydrophilicity, and/or enhance blood compatibility and reduce thrombogenic surface activity. For example, an anti-thrombogenic coating or treatment can be applied to the curved struts 104, hub 120, and/or detachment element 122.
In some embodiments, the device 100 is configured to transform between a first, low-profile configuration suitable for delivery via an elongate shaft (e.g., a delivery catheter) and a second, expanded configuration suitable for bridging the neck of an aneurysm (e.g., the configuration illustrated in
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The coil 212 can have a length from 2 cm to 30 cm, from 3 cm to 25 cm, or from 4 cm to 20 cm. In some embodiments, the length of the coil 212 depends on the size of the aneurysm being treated. For example: for an aneurysm 4 mm in diameter or less, the coil 212 can have a length of about 6 cm; for an aneurysm 5 mm in diameter or less, the coil 212 can have a length of about 8 cm; for an aneurysm 6 mm in diameter or less, the coil 212 can have a length of about 15 cm; for an aneurysm 7 mm in diameter or less, the coil 212 can have a length of about 15 cm; for an aneurysm 8 mm in diameter or less, the coil 212 can have a length of about 20 cm; and, for an aneurysm 9 mm in diameter or less, the coil 212 can have a length of about 20 cm.
The coil 212 can be made from metals, alloys, polymers, shape memory materials (e.g., Nitinol), platinum, rhodium, palladium, tungsten, gold, silver, cobalt-chromium, platinum tungsten, and/or various alloys of these materials. In some embodiments, the coil 212 is heat set to form a tertiary structure (e.g., a pre-determined three-dimensional structure) when in a deployed state. For example, the coil 212 can have a preset tertiary structure that biases the coil into a bundled or more globular state that facilitates positioning of the coil 212 between the deployed device 100 and the aneurysm wall. In other embodiments, however, the coil 212 may not have a tertiary structure.
As previously mentioned, embolic coils such as the coil 212 can be very effective at filling space within the aneurysm cavity. However, there is a risk that the coil 212 may prolapse through the neck N of the aneurysm A into the vessel V, particularly if the aneurysm A is a wide-necked aneurysm. The device 100 can address this challenge via the curved struts 104 that are positioned over the aneurysm neck N to support the coil 212 and prevent the coil 212 from protruding into the neck, while the anchor structure 102 braces against the aneurysm wall to resist the outward pressure toward the vessel V exerted by the packed coil 212 so the device 100 does not bulge into the vessel V.
The methods of the present technology can be performed under fluoroscopy such that the radiopaque portions of the device 100 can be visualized by the physician to ensure proper neck coverage. If the device 100 is not positioned properly, the physician can withdraw the device 100 into the first elongate shaft 202, reposition, and deploy again. Additionally, in embodiments where the coil 212 is radiopaque, the physician can use fluoroscopy to confirm that the coil 212 does not protrude from the neck N of the aneurysm A after deployment.
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In some embodiments, some or all of the filaments 426 (e.g., at least 25%, 50%, 80%, or 100% of the filaments 426) are made of one or more shape memory and/or superelastic materials (e.g., Nitinol). The braid can have, for example, from 32 to 144 filaments 426, such as 64 or 72 filaments 426. Some or all of the filaments 426 can have a diameter from 0.0010 inches to 0.0012 inches, such as a diameter of 0.0010 inches, 0.0011 inches, or 0.0012 inches (at least prior to etching). In some embodiments, some or all of the filaments 426 are drawn-filled tubes (“DFT”) having a radiopaque core (e.g., platinum) surrounded by a shape memory alloy and/or superelastic alloy (e.g., Nitinol, cobalt chromium, etc.). Radiopaque markers can alternatively or additionally be incorporated into other portions of the device 400, e.g., at or near the distal end portion 408, proximal end portion 406, curved struts 404, hub 420, etc. All or a portion of the length of some or all of the filaments 426 can have one or more coatings or surface treatments. For example, some or all of the filaments 426 can have a lubricious coating or treatment that reduces the delivery force as the device 400 is advanced through the delivery catheter. In some embodiments, the coating is relatively hydrophilic, such as a phosphorocholine compound. Additionally or alternatively, some or all of the filaments 426 can have a coating or treatment (the same as the lubricious coating, or a different coating) that enhances blood compatibility and reduces the thrombogenic surface activity of the braid. Optionally, at least a portion of the filaments 426 can be made of other suitable materials.
In some embodiments, the anchor structure 402 and curved struts 404 are integrally formed as a single unitary component. For example, the curved struts 404 can be formed from the same filaments 426 used to form the braid of the anchor structure 402. In such embodiments, each curved strut 404 can be made from one or more filaments 426 that are bundled, twisted, braided, or otherwise assembled into a single elongate component. Alternatively, the anchor structure 402 and curved struts 404 can be discrete components that are attached to each other, e.g., using welding, adhesives, fasteners, or other suitable techniques. In such embodiments, the curved struts 404 can be formed of known flexible materials, including shape memory and/or superelastic materials (e.g., Nitinol), cobalt chromium, platinum, stainless steel, other metals or metal alloys, or a combination thereof, and can be manufactured by laser-cutting, etching, metal injection molding, braiding, etc.
In the illustrated embodiment, the curved struts 504 each have a first end region 516 disposed adjacent a central aperture 524 and a second end region 518 coupled to the anchor structure 502. At the first end region 516, each curved strut 516 abuts a proximal extension 526 that extends proximally away from the plane defined by the curved struts 504. As best seen in
In some embodiments, the central aperture 524 can be defined by a partially or fully continuous circumferential ring. For instance, the first end regions 516 of the curved struts 504 may connect to the ring defining the central aperture 524. The proximal extensions 526 may extend proximally away from the ring, or may be omitted entirely. In some implementations, the ring defining the central aperture 524 can facilitate releasable coupling of the occlusive device 500 to a delivery element (e.g., a pusher member). For instance, an elongate member such as a wire may extend through the central aperture 524 and have a distal anchor disposed distal to the central aperture 524 to secure the wire in place. A proximal portion of the wire can be coupled to or form a part of an elongate delivery member (e.g., a pushwire, hypotube, etc.). To detach the occlusive device, the wire itself can be severed via electrolytic detachment or other mechanism. Additionally or alternatively, the elongate delivery member can be separated from the wire (which is secured to the occlusive device 500) via a mechanical engagement mechanism. Similar releasable engagement techniques can be used for any of the occlusive devices described herein.
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In some examples, some or all of the protrusions 530 that extend away from one of the curved struts 504 can have a second end region 536 that is attached to the anchor structure 502 and/or to another curved strut 504. In such configurations, the protrusion 530 assumes the form of a “branching” of the curved strut 504 in the radially outward direction. Among examples, such branching configurations may reduce the resheathing force needed to collapse the occlusive device 500 from the expanded configuration into a constrained configuration for placement within a delivery catheter.
The protrusions 530 can assume a variety of different shapes, sizes, and configurations. For instance, the protrusions 530 can have straight, arcuate, curved, semi-circular, or semi-elliptical shapes. Protrusions 530 can also have more complex shapes, such as zig-zag, undulating, serpentine, sinusoidal, etc. In some embodiments, the direction of curvature for some or all of the protrusions 530 can be inward toward the central aperture 524 or alternatively direction of curvature can be in the opposite direction (e.g., curving radially outwardly toward the anchor structure 502).
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The presence of the protrusions 530 can increase the total material coverage area of the occlusive device over the central opening defined by the ring-shaped anchor structure 502. This increased material coverage area can improve the occlusive effect of the device 500 when implanted within an aneurysm. Depending on the number, configuration, and dimensions of the curved struts 504 and/or the protrusions 530, the material coverage proportion can be selected to achieve a desired coverage ratio. For instance, when the device 500 is viewed from above and in the expanded configuration (as shown in
With continued reference to
The protrusions 830 can extend in a generally circumferential direction (e.g., annularly or circumferentially extending around the central aperture 824). As illustrated, the protrusions 830 can have undulating, curved, serpentine, sinusoidal, or other profile, with any suitable number of undulations, curves, bends, etc along their respective lengths. In the illustrated example, those protrusions 830 nearer to the central aperture 824 can have more undulations (e.g., be further displaced from a semi-circular arc) than other protrusions 830 that are positioned more radially outwardly. In some implementations, providing protrusions 830 that extend entirely from one curved strut 804 to another curved strut 804 can increase the material coverage of the occlusive device compared to the example shown in
Although many of the embodiments are described above with respect to systems, devices, and methods for treating a cerebral aneurysm, the technology is applicable to other applications and/or other approaches. For example, the occlusive devices, systems, and methods of the present technology can be used to treat any vascular defect and/or fill or partially fill any body cavity or lumen or walls thereof, such as for parent vessel take down, endovascular aneurysms outside of the brain, arterial-venous malformations, embolization, atrial and ventricular septal defects, patent ductus arteriosus, left atrial appendage, and patent foramen ovale. Additionally, several other embodiments of the technology can have different states, components, or procedures than those described herein. It will be appreciated that specific elements, substructures, advantages, uses, and/or other features of the embodiments described can be suitably interchanged, substituted or otherwise configured with one another in accordance with additional embodiments of the present technology. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described above with reference to
The descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.
As used herein, the terms “generally,” “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.
Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. As used herein, the phrase “and/or” as in “A and/or B” refers to A alone, B alone, and A and B. Additionally, the term “comprising” is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and/or additional types of other features are not precluded.
It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.