EXPANDABLE DEVICES FOR TREATING BODY LUMENS
20230165587 · 2023-06-01
Inventors
Cpc classification
International classification
Abstract
Devices, systems, and methods for treating vascular defects are disclosed herein. One aspect of the present technology, for example, includes an occlusive device comprising a mesh having a low-profile state for intravascular delivery to the aneurysm and a deployed state. The mesh may comprise an expandable cage formed of a plurality of mesh stmts. In some embodiments, the cage is configured to receive an embolic material therein.
Claims
1. An occlusive device for treating an aneurysm, the device comprising: an expandable cage formed of a plurality of struts, the expandable cage having a first end region, a second end region, and an intermediate region extending between the first and second end regions, wherein each of the struts have a first end portion at the first end of the expandable cage and a second end portion at the second end of the expandable cage, wherein at least one of the struts comprises a mesh, wherein the expandable cage has a low-profile state for intravascular delivery to the aneurysm and an expanded state in which the expandable cage is configured to be implanted within the aneurysm cavity such that the struts provide an open framework across a neck of the aneurysm.
2. The device of claim 1, wherein each of the struts comprises a mesh.
3. The device of claim 1, wherein the expandable cage has a substantially prolate spheroid shape in an expanded, unconstrained state.
4. The device of claim 1, wherein the expandable cage has a substantially spherical shape in an expanded, unconstrained state.
5. The device of claim 1, wherein the first end portions of the struts come together at the first end region of the expandable cage to form a closed, curved first end surface.
6. The device of claim 1, wherein the second end portions of the struts come together at the second end region of the expandable cage to form a closed, curved second end surface.
7. The device of claim 1, wherein the first end portions of the struts are fixed relative to one another and the second end portions of the struts are fixed relative to one another.
8. The device of claim 1, wherein the at least one strut comprises a braided filament.
9. The device of claim 1, wherein the at least one strut comprises an interwoven filament.
10. The device of claim 1, wherein the at least one strut comprises a helically wound filament.
11. The device of claim 1, wherein the at least one strut comprises a plurality of braided filaments.
12. The device of claim 1, wherein the at least one strut comprises a plurality of interwoven filaments.
13. The device of claim 1, wherein the at least one strut comprises a plurality of helically wound filaments.
14. The device of claim 1, wherein each of the plurality of struts extends along a longitudinal dimension of the expandable cage.
15. The device of claim 1, wherein the struts are spaced apart about a circumference of the expandable cage along the intermediate region.
16. The device of claim 1, wherein the expandable cage is self-expanding.
17. The device of claim 1, wherein the mesh is formed of a plurality of filaments, and wherein at least some of the filaments are drawn-filled tube (“DFT”) wires.
18. The device of claim 1, wherein the proximal end region of the expandable cage is configured to be detachably coupled to an elongated delivery member.
19. The device of claim 1, wherein the first end region comprises a connecting structure, the connecting structure being recessed in a cavity of the expandable cage when the expandable cage is positioned within the aneurysm.
20. The device of claim 1, wherein the second end region comprises a connecting structure, the connecting structure being recessed in a cavity of the expandable cage when the expandable cage is positioned within the aneurysm.
21. The device of claim 1, further comprising a circumferential strut extending about the circumference of the expandable cage at the intermediate region.
22-67. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] 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.
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DETAILED DESCRIPTION
[0038] Embolic coils are currently used for embolization of aneurysms but come with several drawbacks. For instance, embolic coils typically do not provide a sufficient surface area for blood to clot, and thus many coils are typically required to fill a single aneurysm, thereby increasing procedural time, cost, and complexity. Additionally, in some cases one or more of the coils may be situated in such a way that creates considerable gaps between adjacent coils, into which blood may freely flow. The addition of extra coils into the aneurysm does not always solve this problem as deploying too many coils into the aneurysm may lead to an undesired rupture. Because the coils are much smaller than the aneurysm cavity, it can be difficult to keep the coils confined to the cavity. As a result, often times one or more of the coils may protrude into the parent vessel with potentially fatal consequences for the patient.
[0039] A current approach to treating saccular aneurysms that seeks to avoid the foregoing issues includes covering the neck of the aneurysm with an intravascularly delivered device (also known as a flow diverter). In one variation of this approach, the device is positioned within the parent vessel and thus blocks blood from flowing into the aneurysm cavity from an extrasaccular position. However, because the device is placed within the parent vessel, extrasaccular flow diverters require dual-antiplatement treatment, which comes with increased complications for the patient. Another type of flow diverter is positioned within the aneurysm cavity and thus blocks blood from flowing into the cavity from an intrasaccular position. Examples of commercially available intrasaccular flow diverters are the WEB® SL and WEB® SLS device (Microvention, Aliso Viejo, Calif., USA). Intrasaccular flow diverters, however, are challenging to size, as every aneurysm has a unique shape and a neck width. If the device is too small, for example, it may herniate into the parent vessel with potentially fatal consequences for the patient.
[0040] As discussed herein, the occlusive devices of the present technology advantageously address all of the foregoing challenges. The present technology may comprise, for example, an expandable cage configured to be placed within the aneurysm, as opposed to an intravascularly placed stent, which eliminates the need for dual anti-platelet treatment and which lowers procedural complications. The expandable cage can be formed of a plurality of mesh struts, each of which provides an increased surface area for clot formation as opposed to a coil or a solid strut. Moreover, the expandable cage is configured to provide a flexible frame for receiving and supporting one or more embolic coils therein. The mesh struts of the present technology are significantly more flexible than the struts of a traditional stent. For example, the mesh struts of the present technology can flex and bend at any location along their respective longitudinal axes, including at multiple locations simultaneously such that a corresponding strut includes multiple inflection points and/or concavities along its length. Each of the mesh struts herein can also stretch and compress along their respective longitudinal axes, in unison or independently of one another. As a result, the expandable cage of the present technology can adapt and conform to a variety of aneurysm shapes and sizes.
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[0042] The occlusive device 100 and/or cage 102 has a low-profile state (not shown) for intravascular delivery to the aneurysm and a deployed state in which the device 100 is configured to be positioned within the interior cavity of the aneurysm. According to some aspects of the technology, the occlusive device 100 is configured to be advanced through a microcatheter as small as a 0.017-inch microcatheter. When the device 100 is implanted, at least one of the struts 104 is configured to be positioned over at least a portion of the neck of the aneurysm while the subsequently delivered coil(s) fill space within the aneurysm cavity. Positioned across at least a portion of the neck, the cage 102 reduces blood flow entering the sac of the aneurysm, prevents herniation of the coil(s) through the neck and into the parent vessel, and provides a scaffolding that promotes endothelialization across the covered portion of the neck, thus further reducing inflow.
[0043] According to several embodiments, for example as shown in
[0044] In some embodiments, for example as shown in
[0045] Depending on the geometry of the aneurysm to be treated, the cage 102 may have other shapes or configurations and may be formed in a similar manner on molds having other shapes or sizes, such as spherical and non-spherical shapes, cylinders, hemispheres, polyhedrons (e.g., cuboids, tetrahedrons (e.g. pyramids), octahedrons, prisms, etc.), oblate spheroids, plates (e.g., discs, polygonal plates), bowls, non-spherical surfaces of revolution (e.g., toruses, cones, cylinders, or other shapes rotated about a center point or a coplanar axis), and combinations thereof. In its expanded state, the cage 102 may have a size and shape suitable for fitting snugly within a vascular cavity or vesicle (e.g., an aneurysm, or perhaps, a fistula). In some embodiments, the cage 102 may comprise multiple portions of different substantially spherical sizes, which when relaxed and in the expanded configuration nest concentrically, or non-concentrically, with each other within the vascular cavity.
[0046] While the cage embodiments represented by
[0047] According to some embodiments, for example as shown in the enlarged view of a portion of one of the struts 104 in
[0048] In some embodiments, all or a portion of one, some, or all of the struts 104 may be formed of a flattened, tubular braid such that each strut 104 comprises two mesh layers that meet at folds at the side edges of the strut 104. For example, in some embodiments, all or a portion of one, some, or all of the struts 104 may be formed of a tubular braid that has been heat set after being flattened on a flat mandrel such that opposing portions of the tubular sidewall are pressed toward one another along the length of the tubular braid, thereby “flattening” the tubular braid while conforming the braid to planar shape of the mandrel. In some embodiments, one, some, or all of the struts 104 comprise a single layer of mesh.
[0049] One, some, or all of the struts 104 can have the same cross-sectional dimension or different cross-sectional dimensions. One, some, or all of the struts 104 can have the same cross-sectional shape or different cross-sectional shapes. Suitable shapes include a rectangle, an square, a circle, an oval, and/or other shapes.
[0050] In some embodiments, one, some, or all of the struts 104 have an inner lumen surrounded by a mesh wall that defines the shape of the strut 104.
[0051] In those embodiments where one or more of the struts 104 comprise a filament or a plurality of filaments, the mesh strut 104 may be formed of a plurality of wires, at least some of which (e.g., 25% of the wires, 50% of the wires, 80% of the wires, 100% of the wires, etc.) are made of one or more shape memory and/or superelastic materials. Some or all of the wires may have a diameter between about 0.0010 inches and about 0.0012 inches, about 0.0010 inches, about 0.0011 inches, 0.0012 inches (at least prior to etching). In some embodiments, some or all of the wires may be 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.).
[0052] All or a portion of the length of some or all of the struts 104 (or components thereof) may have one or more coatings or surface treatments. For example, some or all of the struts 104 may have a lubricious coating or treatment that reduces the delivery force of the device 100 and/or cage 102 as the device 100 is advanced through the delivery catheter. In some embodiments, the coating may be relatively hydrophilic, such as a phosphorocholine compound. Additionally or alternatively, some or all of the struts 104 (or components thereof) may 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 (e.g., an antithrombogenic coating). In these and other embodiments, at least a portion of the struts 104 (or components thereof) can be made of other suitable materials.
[0053] In these and other embodiments, all or a portion of one, some, or all of the struts 104 may be a helically wound coil or any elongated porous structure. In any of the foregoing embodiments, auxiliary fibrous materials may be optionally added to all or a portion of one, some, or all of the struts 104 by weaving, tying, or other suitable permanent attachment methods.
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[0055] According to some embodiments, an embolic material, such as coil 300, may then be delivered into the interior volume of the cage 102. The embolic material 300 may be delivered through the same catheter that delivered the cage 102, or through a different catheter that has been advanced to the aneurysm A such that a distal portion is proximate or distal of the struts 104 positioned over the neck N. When the physician has been satisfied that the aneurysm is sufficiently occluded, the occlusive device 100 may be detached from the delivery member (such as a pusher member) via one or more detachment mechanisms.
[0056] In some cases, the physician may choose to deliver additional coils or embolic material (such as a liquid embolic) to the aneurysm to facilitate delivery, engagement with the aneurysm, or increase of the packing density or fill volume. In these scenarios, the physician may withdraw the pusher member from the delivery catheter and, while maintaining the tip of the delivery catheter within the aneurysm sac (beyond the mesh positioned across the neck), the physician may push the additional embolic material through the delivery catheter and into the aneurysm. The embolic material may comprise one or more liquid embolics, polymers, hydrogels, foams, framing components, and other suitable embolic elements. Any of these embodiments can increase the packing density or fill volume to avoid recanalization of the aneurysm.
[0057] Some or all of the cage 102 and/or struts 104 may comprise a radiopaque material. The methods of the present technology may be performed under fluoroscopy such that the radiopaque portions of the device 100 and/or cage 102 may be visualized by the physician to ensure proper neck coverage.
[0058] It will be appreciated that one, some, or all of the features and methods described with respect to
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[0060] As shown in
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CONCLUSION
[0066] 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 to treat parent vessel occlusion, endovascular aneurysms outside of the brain, arterial-venous malformations, embolism, atrial and ventricular septal defects, patent ductus arteriosus, 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
[0067] 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.
[0068] 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.
[0069] 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. 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.