Patent Description:
In general, an aneurysm is a swelling or bulge that forms a cavity in the wall of a blood vessel. One type of aneurysm is a cerebral aneurysm, which forms in an artery of the brain. A cerebral aneurysm may develop suddenly without initial symptoms, and can cause extreme pain. In general, in <NUM>% of cerebral aneurysm cases, the patient dies suddenly upon development of the cerebral aneurysm; in another <NUM>% of cerebral aneurysm cases, the patient dies under medical treatment; and in <NUM>% of cerebral aneurysm cases, the patient survives after treatment but feels an acute aftereffect. As such, a cerebral aneurysm (or any aneurysm) is a very concerning development.

The treatment of aneurysms and other similar vascular disorders often involves the placement of microcoils within the cavity formed by the aneurysm or disorder. Doing so can cause blood to clot, prevent an additional inflow of blood, and decrease the risk of the aneurysm or disorder rupturing (i.e., an embolization). In order to be effective, an embolic microcoil must apply pressure sufficient to prevent additional inflow of blood, but not an excessive amount of pressure that causes rupture.

An important feature of an embolic device is its ability to block the aneurysm's neck, i.e., the opening where the aneurysm meets the blood vessel. Such blockage can be critical for ensuring that excessive amounts of blood do not flow into the aneurysm, risking further bulging or rupture. Prior approaches for blocking the aneurysm neck include covering the neck with stent-like or braided structures. While these approaches can sometimes be effective, there are still opportunities for improvement. Accordingly, there is a need for an improved embolic device that achieves improved filling and/or blockage of a neck of an aneurysm.

<CIT> describes a device for treating a vascular malformation, including a wire having a coilable section configured to be coiled into a coil positionable within the vascular malformation; wherein said coil comprises a sequence of concentric loops. The coil is configured to line/bridge a neck of the vascular malformation so as to at least partially cover an orifice thereof, when in use; and optionally comprises a docking section configured to anchor and/or stabilize and/or assist in the positioning of the device within the vascular malformation, when in use.

<CIT> describes an occlusive device, occlusive device delivery system, method of using, and method of delivering an occlusive device, and method of making an occlusive device to treat various intravascular conditions.

<CIT> describes an embolic device comprised of a linear sequence of flexibly interconnected miniature beads. The device generally comprises a flexible elongate filament having a linear sequence of miniature beads disposed thereon.

According to an aspect of the invention, there is provided a multi-stage embolic device for use in treating a vascular disorder according to claim <NUM>. Optional and/or preferable features are outlined in the dependent claims.

In various embodiments, the present invention relates to an improved embolic device that achieves improved filling and neck blockage over conventional devices. In particular, the device can be formed into inventive shapes that have been observed to improve neck blockage. Exemplary shapes include spiral shapes and infinity shapes, as described in greater detail below.

In addition, one factor that has been discovered to contribute significantly to unsatisfactory neck blockage in conventional devices is that the portion of the embolic device placed within the aneurysm often shifts or moves while it finds equilibrium within the aneurysm. This can take place, for example, when the aneurysm has a complex shape (e.g., bifurcated, bilobed, etc.) and the portion of the embolic device within the aneurysm expands in order to contact portions of the interior surface of the aneurysm. Movement of the portion of the device within the aneurysm can cause associated shifts/movement of the portion of the embolic device blocking the neck, which can compromise the blockage. As such, in some aspects, the invention described herein includes an embolic device that includes two treatment elements: one for placement in the aneurysm and the other for blockage of the neck. The two treatment elements can be attached with an interconnect element that allows the treatment elements to have independent freedom of motion when delivered to the aneurysm.

In general, in one aspect, embodiments of the invention feature an embolic device for use in treating a vascular disorder. The embolic device can include a flexible structure that includes a series of alternating narrow portions and link portions, each link portion circumscribing an opening in at least one plane. The structure can be adapted to form a spiral shape when unconstrained.

In various embodiments, the structure can include a coil, a flat sheet, a thin film, and/or combinations thereof. The structure can include a material including platinum, nitinol, alloys thereof, and/or combinations thereof. In some cases, the structure includes a thickness in a range from <NUM> centimetres (<NUM> inches) to <NUM> centimetres (<NUM> inches). In some cases, each narrow portion includes a helically wound coil and each link portion includes a flat sheet and/or a thin film. At least a portion of the embolic device can be radiopaque. Each narrow portion can be fixedly attached to proximate link portions. In some cases, the embolic device can include a strain relief element (e. g, a melted suture material, melted polymer, etc.) between each narrow portion and the proximate link portions. In some cases, each link portion includes a diamond-like shape.

In various embodiments, each link portion is adapted to compress when the embolic device is disposed within a microcatheter. Each link portion can be further adapted to expand upon deployment of the embolic device from the microcatheter. In some cases, the narrow portions and the link portions alternate with consistent spacing. In other cases, the narrow portions and the link portion alternate with inconsistent spacing. The embolic device can include a cover element disposed over the structure. The embolic device can include an interconnect element disposed at an end of the embolic device for attaching the embolic device to one or more different embolic devices (e.g., in series).

In general, in another aspect, embodiments of the invention feature another embolic device for use in treating a vascular disorder. The embolic device can include a flexible structure adapted to form at least one infinity shape portion when unconstrained. The infinity shape portion can include two adjacent loops crossing at a single point.

In various embodiments, the structure includes a coil, a flat sheet, a thin film, and/or combinations thereof. The structure can include a material that includes platinum, nitinol, alloys thereof, and/or combinations thereof. In some instances, the structure includes a thickness in a range from <NUM> centimetres (<NUM> inches) to <NUM> centimetres (<NUM> inches). In some cases, the flexible structure forms at least two infinity shape portions. At least two of the infinity shape portions can be arranged to align with and overlay each other and/or at least two infinity shape portions can be arranged circumferentially about an interior of the vascular disorder. At least one infinity shape portion can be rotated to be perpendicular to another infinity shape portion. The embolic device can include a cover element disposed over the structure. The embolic device can include an interconnect element disposed at an end of the embolic device for attaching the embolic device to one or more different embolic devices (e.g., in series).

In general, in yet another aspect, embodiments of the invention feature a multi-stage embolic device for use in treating a vascular disorder. The multi-stage embolic device can include a first embolic device, a second embolic device different from the first embolic device, and an interconnect element joining the first and second embolic devices and permitting independent freedom of motion between the first and second embolic devices while remaining joined together.

In various embodiments, the first embolic device includes a framing device and the second embolic device includes a filling device. In some cases, upon deployment of the multi-stage embolic device to the vascular disorder, the first embolic device is adapted to block a neck of the vascular disorder and the second embolic device is adapted to occupy an interior of the vascular disorder. The first and/or second embolic devices can include a coil, a flat sheet, a thin film, and/or combinations thereof. The first and/or second embolic devices can include platinum, nitinol, alloys thereof, and/or combinations thereof. In some instances, the first and/or second embolic devices include a thickness in a range from <NUM> centimetres (<NUM> inches) to <NUM> centimetres (<NUM> inches). In some cases, the first and/or second embolic devices are adapted to form a spiral shape when unconstrained. The interconnect element can include linked loops and/or a nitinol coil. The multi-stage embolic device can further include at least one additional embolic device different from each of the first and second embolic devices, and at least one additional interconnect element directly and/or indirectly joining the second and additional embolic device(s). The additional interconnect element(s) permit independent freedom of motion between the second and additional embolic device(s) while remaining joined together. The multi-stage embolic device can include a cover element disposed over the first and/or second embolic devices.

In general, in still another aspect, a method for treating a vascular disorder is disclosed. Said method does not form part of the claimed invention. The method can include the step of delivering a multi-stage embolic device to the vascular disorder. The multi-stage embolic device may include a first embolic device, a second embolic device different from the first embolic device, and an interconnect element joining the first and second embolic devices and permitting independent freedom of motion between the first and second embolic devices while remaining joined together. The method can further include disposing the second embolic device within an interior of the vascular disorder, and disposing the first embolic device to block a neck of the vascular disorder.

In various embodiments, one of the first and second embolic devices includes a framing device and the other embolic device includes a filling device. The first and/or second embolic devices can include a coil, a flat sheet, a thin film, and/or combinations thereof. The first and/or second embolic devices can include platinum, nitinol, alloys thereof, and/or combinations thereof. In some instances, the first and/or second embolic devices include a thickness in a range from <NUM> centimetres (<NUM> inches) to <NUM> centimetres (<NUM> inches). In some cases, the first and/or second embolic devices form a spiral shape when unconstrained. The interconnect element can include linked loops and/or a nitinol coil. The multi-stage embolic device can further include at least one additional embolic device different from each of the first and second embolic devices, and at least one additional interconnect element directly and/or indirectly joining the second and additional embolic devices. The additional interconnect element(s) permit independent freedom of motion between the second and additional embolic devices while remaining joined together, and the method can further include disposing the additional embolic device(s) within the interior of the vascular disorder. The multi-stage embolic device can include a cover element disposed over the first and/or second embolic devices.

These and other objects, along with advantages and features of the embodiments of the present invention herein disclosed, will become more apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.

In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:.

Embodiments of the present invention are directed toward an improved design for an embolic device and methods of using the improved device. Neck blockage is an important function for embolic devices because it determines how much fluid can pass through the embolic device into the aneurysm, which can directly impact how effective the embolic device is in treating the vascular disorder. Embodiments of the present invention include embolic devices having shapes and/or configurations that accomplish improved neck blockage and other performance parameters over conventional devices.

In general, all of the embolic devices described herein can take any known form, e.g., a microcoil (e.g., bare platinum coil), flat sheet, thin film, combinations thereof, etc., even though in some instances a particular device may only be described herein as having one of these forms. In addition, all of the embolic devices described herein can be formed from any suitable material, e.g., shape memory material (e.g., nitinol), platinum, combinations thereof, etc., even though in some instances a particular device may only be described herein as being formed of one of these materials. Furthermore, in various instances, all of the embolic devices described herein can include a structure (e.g., microcoil, flat sheet, thin film, etc.) covered by a cover element, as described for example in U. Patent Publication No. <CIT>.

In various embodiments of the invention, an embolic device is formed from a structure. As shown for example in <FIG>, the embolic device <NUM> may be adapted to form a spiral shape upon deployment to an aneurysm <NUM> (reference numeral <NUM> can also apply to any other vascular disorder or similar anatomic structure). As used herein, the shape of the embolic device <NUM> refers to a macro shape formed by the embolic device <NUM> itself (or a portion thereof), as opposed to a micro shape used to form the structure <NUM>. For example, in some instances, the embolic device <NUM> includes a structure <NUM> that is formed from a spirally wound wire <NUM>, as shown in <FIG>. In the example of <FIG>, although the structure <NUM> is spirally wound, the macro shape into which it is formed to create the embolic device is not spirally wound, instead forming a series of curved, lobe-shaped loops. Thus, when the shape of the embolic device <NUM> is described herein it should be understood as having this macro shape meaning.

As shown in <FIG>, the embolic device <NUM> can be used to treat a vascular disorder <NUM> that has a neck <NUM>, e.g., an opening between a blood vessel and a cavity of the aneurysm <NUM>. In some instances, the embolic device <NUM> can include a portion <NUM> disposed within and/or blocking the aneurysm neck <NUM> and another portion <NUM> disposed within the cavity of the aneurysm <NUM>. In general, the portion <NUM> blocking the neck <NUM> can take any shape, e.g., a spiral shape as shown in <FIG>. The spiral shape of the portion <NUM> can be formed in any suitable three dimensional shape, e.g., a disc (as shown in <FIG>), a sphere, a semi-sphere (or partial-sphere), a cone, etc. The portion <NUM> having a spiral shape has been observed to accomplish improved blockage of the neck <NUM> over conventional devices. The portion <NUM> disposed within the cavity of the aneurysm <NUM> can also take any shape, which can be the same or a different shape as the portion <NUM> blocking the aneurysm neck <NUM>. For example, as shown in <FIG>, the portion <NUM> can have a spiral shape, but in other embodiments it can have other shapes, including random or non-geometric shapes. The spiral of the portion <NUM> can also be formed in any suitable three-dimensional shape, e.g., a disc, a sphere, a semi-sphere (or partial sphere), a cone (as shown in <FIG>), etc..

One problem experienced with conventional devices is that their effectiveness in blocking an aneurysm neck is significantly affected by the orientation of the device upon delivery to a treatment site, which can sometimes be difficult to accomplish in a repeatable manner. Embodiments of the present invention solve this problem by featuring an embolic device that effectively blocks the aneurysm neck <NUM> regardless of its orientation upon placement into the aneurysm <NUM> or, in some cases, that blocks the aneurysm neck <NUM> in many more orientations than a conventional device (e.g., the majority of the orientations).

One example of a device that blocks the aneurysm neck <NUM> in a majority (or, in some cases, all) orientations is the embolic device <NUM> shown in <FIG>, which has a substantially spherical spiral shape. When a geometric shape is described herein, in various embodiments, it includes a shape having all of its dimensions within <NUM>% of a perfect geometric version of the shape, e.g., <NUM>%, <NUM>%, <NUM>%, <NUM>%, and/or <NUM>%. As illustrated in <FIG>, the embolic device <NUM> can be deployed into the aneurysm <NUM> in any <NUM> degree orientation and still effectively block the neck <NUM> and also contact the interior wall (endothelium) of the aneurysm. In some instances, the substantially spherical spiral shaped embolic device <NUM> can allow for continuous growth of tissue throughout the device <NUM>. For example, the embolic device <NUM> can provide a continuous path for tissue to grow within the aneurysm cavity, which can enable and/or accelerate healing of the aneurysm <NUM>.

Example dimensions of the embolic device <NUM> are shown in <FIG>. The primary diameter (see element <NUM> in <FIG>) can be about <NUM> centimetres (<NUM> inches). The height of the device (distance between top-most coil and bottom-most coil) can be about <NUM>. The diameter of the widest portion of the spherical spiral can be about <NUM>. The outer diameter of the bottom-most coil can be about <NUM> and the inner diameter of the bottom-most coil can be about <NUM>. The top-most coil can have similar dimensions to the bottom-most coil.

In various embodiments, embolic devices of the present invention can be formed from a flat sheet (e.g., formed from nitinol). In general, the flat sheet can be formed into any suitable shape. For example, <FIG> show top views of example embolic devices 500a, 500b formed from a flat sheet in a spiral shape. As mentioned above, the spirals can take any suitable 3D shape, e.g., disc, sphere, semi-sphere (or partial sphere), cone, etc. The flat sheet can also have any desirable thickness, e.g., in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"). In another embodiments, the flat sheet has a thickness in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"). In some instances, the width of the flat sheet has a constant width, as shown for example by the embolic device 500a in <FIG>. In other instances, the width of the flat sheet has a drafted or tapered (e.g., decreasing or increasing) width, as shown for example by the embolic device 500b in <FIG>.

In various embodiments, as shown in <FIG>, an embolic device <NUM> can be formed by connecting two spiral elements <NUM>, <NUM> at a connection region <NUM>. In general, the spiral elements <NUM>, <NUM> can be formed from any suitable structure, e.g., microcoil, flat sheet (as shown in <FIG>), thin film, etc. In general, the connected spiral elements can form any 3D shape, e.g., disc, sphere, semi-sphere (or partial sphere), cone, etc. With reference to <FIG>, as one example, if an end point <NUM> of the first spiral element <NUM> is pulled out of the page, a cone shaped spiral is formed. As another example, if an end point <NUM> of the second spiral element <NUM> is also pushed into the page, a sphere shaped spiral is formed. In general, the spiral elements <NUM>, <NUM> can be joined at the connection region <NUM> using any suitable technique, e.g., welding (e.g. laser, arc, resistance, friction stir), soldering, brazing, diffusion bonding, adhesive joining, and interconnect element (e.g., as described below), etc. In other embodiments, both spiral elements <NUM>, <NUM> can both be cut (e.g., laser cut) from a single piece of material (i.e., the spiral elements <NUM>, <NUM> are of unitary construction with each other).

In various embodiments, an embolic device <NUM> can include alternating narrow portions <NUM> and link portions <NUM>, as shown for example in <FIG>. The link portions <NUM> circumscribe an opening in at least one plane, e.g., the plane of the page, as shown in <FIG>. In general, the link portions <NUM> can have any suitable shape, e.g., diamond-like (e.g., as shown in <FIG>), circular, rectangular, triangular, etc. In general, the embolic device <NUM> can be formed from any suitable structure, e.g., a coil, a flat sheet, a thin film, combinations thereof, etc. For example, as shown in <FIG>, the narrow portions <NUM> can be formed of a single strip of flat sheet material (or multiple strips of flat sheet material with no opening in between) and the link portions <NUM> can be formed by at least two strips of flat sheet material that define a perimeter around or circumscribes an opening. The embolic device <NUM> can also have any desirable thickness, e.g., in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"), in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>"). In another embodiment, the embolic device has a thickness in a range from <NUM> centimetres to <NUM> centimetres (<NUM>" to <NUM>").

In some instances, as shown for example in <FIG>, the narrow portions include coil segments <NUM>. In some cases, the coil segments <NUM> are disposed over another structure (e.g., a flat sheet, thin film, etc.). In other cases, the coil segments <NUM> are not disposed over another structure. In general, the coil segments <NUM> can be attached to the link portions <NUM> using any known technique, e.g., melting a suture on the ends of each coil segment <NUM>. Melting a suture on the ends of each coil segment <NUM> can also keep the coil segment <NUM> positioned between the link portions <NUM>. In some instances, the link portions <NUM> can be fixedly attached to proximate narrow portions and a strain relief element <NUM> can be used to relieve strain between the portions. The strain relief element can be formed of any suitable material, e.g., a suture material, a melted polymer (e.g., polypropylene, polyethylene, high density polyethylene, low density polyethylene, polyurethane, polyether block amide, polyamides, polymer adhesives, etc.), etc..

In various embodiments, the embolic devices described herein can be introduced, delivered, positioned, and implanted within a vascular disorder using a microcatheter. The microcatheter can be a flexible, small diameter catheter having, for example, an inside diameter between <NUM> centimetres (<NUM> inches) and <NUM> centimetres (<NUM> inches) (e.g., between <NUM> centimetres (<NUM> inches) and <NUM> centimetres (<NUM> inches)). The microcatheter may be introduced by an introducer sheath/guiding catheter combination placed in the femoral artery or groin area of a patient. In some instances, the microcatheter is guided into the vascular disorder with guidewires (e.g., long, torqueable proximal wire sections with more flexible distal wire sections designed to be advanced within tortuous vessels). Such guidewires may be visible using fluoroscopy and may be used to first access the vascular disorder, thereby allowing the microcatheter to be advanced over it into the disorder.

In some instances, once the tip of the microcatheter has accessed the vascular disorder, the guidewire is removed from the catheter lumen. The embolic device may then be placed into the proximal open end of the microcatheter and advanced through the microcatheter with a delivery mechanism. The embolic device may attach to a delivery mechanism via any suitable structure, e.g., a loop <NUM> (<FIG>) on a proximal end of the device. In some instances, while the embolic device is disposed within the lumen of the microcatheter it is in a straightened out form. A user (e.g., a physician) may advance and/or retract the embolic device several times to obtain a desirable position of the embolic device within the disorder. Once the embolic device is satisfactorily positioned, it can be released into the disorder. Upon release, the device may form its deployed shape, for example the spiral shapes described above, or any other desired configuration. In some instances, the formation of the shape upon deployment into the vascular disorder is caused by the shape-memory nature of the material used to form the embolic device (e.g., nitinol).

Further explanation regarding the shape of the embolic devices described herein at various stages of the delivery process is instructive. The embolic device are generally manufactured to have a particular shape in an unconstrained configuration, e.g., as the device would exist in packaging or an operating room before being delivered to a patient. The particular shape can include any of the embolic device shapes described herein. During delivery, the embolic device is straightened out so that it can fit within and be delivered through a microcatheter (as described above). Once deployed out of the microcatheter to the vascular disorder, the embolic device can reform the shape it was manufactured to have (e.g., aided by a shape memory material). However, in some instances, the embolic device may not reform exactly into the shape it was manufactured to have, based on constraints imposed by the vascular disorder and other surrounding structures.

In various embodiments, the link portions <NUM> of the embolic device <NUM> shown in <FIG> can collapse (e.g., the openings can become narrower) when the embolic device <NUM> is located in a microcatheter during delivery. The link portions <NUM> can then expand (e.g., the openings can become wider) upon deployment of the embolic device to the vascular disorder. This can allow the embolic device <NUM> to be more easily delivered with less friction through a microcatheter, while also effectively blocking the neck of the aneurysm upon deployment. In some instances, the coil segments <NUM> can further reduce friction of the embolic device during delivery through a microcatheter. As one example, the shape of the coil segments <NUM> can better match the shape of a lumen of the microcatheter. As another example, the coil segments <NUM> can increase the flexibility and malleability of the embolic device. As another example, the coil segments <NUM> can be formed of a material that generates less friction with the interior surface of the microcatheter. The coil segments <NUM> can also be formed of a radiopaque material (e.g., platinum) such that the embolic device can be viewed during delivery; for example, if the link portions <NUM> are formed from a non-radiopaque material.

In various embodiments, the aneurysm <NUM> can be treated by an embolic device shaped to form at least one infinity shape portion, as shown for example in <FIG>. As used herein, the term infinity shape refers to any shape formed by two loops (e.g., loops <NUM>, <NUM>) that cross at a common point (e.g., point <NUM>), e.g., a figure eight shape, a lemniscate shape, etc. Notwithstanding any particular geometric or mathematic usages of the term infinity shape in other contexts, as defined herein, the two loops formed by the infinity shape can be of different sizes or the same size. In some instances, the embolic device <NUM> can include multiple infinity shape portions 902a, 902b, 902c (see <FIG>) stacked on top of each other, e.g., arranged to align with and overlay each other, or in some cases arranged circumferentially about an inner perimeter of the aneurysm (see <FIG>). In some instances, the embolic device <NUM> can include a first group of infinity shape portions <NUM> (which can include one or more infinity shape portions) arranged along a first axis and a second group of infinity shape portions <NUM> (which can include one or more infinity shape portions) rotated to be arranged at some angle (e.g., about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, about <NUM>°, and about <NUM>°) with respect to the first axis. For example, the second group of infinity shape portions can be arranged substantially perpendicular to the first axis. Although both <FIG> show infinity shape portions arranged substantially perpendicular to each other, in some instances, all of the infinity shape portions can be arranged along the same axis, e.g., aligned with each other. In other instances, only a single infinity shape portion is formed. Further, although in some instances the infinity shape portions block the neck <NUM> of the aneurysm, in other instances the infinity shape portion can be located in other portions of the aneurysm. For example, as shown in <FIG>, the embolic device can form a series of infinity shape portions that, following deployment, can be arranged circumferentially about the interior perimeter of an aneurysm or other vascular disorder. Such an arrangement can contribute to framing the aneurysm. The infinity shape portions can also be arranged in other patterns. In general, any pattern can be used, including random patterns. Within such patterns, each infinity shape portion can be arranged at any rotational orientation and with any desirable overlap with respect to another infinity shape portion.

In various embodiments, multiple embolic devices can be joined with an interconnect element. The inventors have identified that when the portion of the device that fills the interior of the aneurysm cavity moves (e.g., to expand into apposition with an interior wall of the cavity) it can cause the portion of the device blocking the aneurysm neck to also move or shift, which can impact the effectiveness of the device in blocking the neck.

As a solution to this and other problems, the present invention includes a multi-stage embolic device that includes at least two embolic devices joined by an interconnect element that permits independent freedom of motion and/or relative positioning of each embolic device while they remain joined together. As shown for example in <FIG>, the multi-stage embolic device <NUM> can include a first embolic device <NUM> and a second embolic device <NUM>. The first embolic device <NUM> is different from the second embolic device <NUM>. As used herein, the first embolic device <NUM> being different from the second embolic device <NUM> means that they are two separate devices and not separate portions of a single device of unitary construction or monolithic construction. The first embolic device <NUM> being different from the second embolic device <NUM> means that the first embolic device <NUM> is of non-unitary construction (or non-monolithic construction) with the second embolic device <NUM>. Said another way, the first embolic device <NUM> is not integrally formed with the second embolic device <NUM>. The first embolic device <NUM> being different from the second embolic device <NUM> does not require that the devices <NUM>, <NUM> have any other differences, although, in various instances, the devices <NUM>, <NUM> can have other differences. For example, the first and second embolic devices <NUM>, <NUM> can have the same or different dimensions (length, inner diameter, outer diameter, etc.), the same or different stiffness, the same or different porosity, etc. In general, the first embolic device can take any form; for example, the first embolic device <NUM> can be a framing device that blocks the neck of the aneurysm. In various instances, the first embolic device <NUM> can form any of the particular shapes described above, e.g., a spiral shape, an infinity shape, etc. In general, the second embolic device <NUM> can also take any form; for example, the second embolic device <NUM> can be a filling device that fills the interior cavity of the aneurysm. In various instances, the second embolic device <NUM> can form any of the particular shapes described above, e.g., spiral shape, an infinity shape, etc., or it can take a random or non-geometric shape. In various embodiments, the first embolic device <NUM> and the second embolic device <NUM> can be located at any location within or around the aneurysm <NUM>, not just the locations shown in <FIG>.

In general, an interconnect element <NUM> joins the embolic devices <NUM>, <NUM> and can include any structure that permits independent freedom of motion and/or relative positioning of each embolic device while they remain joined together. As used herein, independent freedom of motion means that the only constraint on the motion between the embolic devices is that they remain coupled. In various instances, any movement about a coupling point is possible. As a result, motion of the second embolic device <NUM> within the aneurysm cavity does not necessarily result in a corresponding motion of the first embolic device <NUM> blocking the neck of the aneurysm. In some instances, permitting this freedom of motion represents an advantage of using an interconnect element to join two embolic devices, as opposed to using separate portions of a single coil (or other device) of unitary construction.

While the separate portions of a single coil (or other device) may have some independence, they are generally more constrained due to the manufacturing realities of manufacturing a coil (or other device) of unitary construction. In contrast, in some instances, joining two different embolic devices with an interconnect element can afford much greater freedom of motion between the devices. In general, the interconnect element <NUM> can be located at any location within or around the aneurysm, depending on where it is advantageous to have independent freedom of motion between the devices, not just the location shown in <FIG>.

As a few non-limiting examples, the interconnect element can include two linked loops, a nitinol coil (in some cases covering another interconnect element, and in other cases by itself), a hook and loop scheme, a hinge, a suture element, a hole and loop, a ball and socket scheme, a pivot joint, a ball and pivot joint, a universal joint, a saddle joint, any mechanical articulating joint with one or more degrees of freedom, or combinations thereof. In some instances, the interconnect element <NUM> can be formed from certain portions of the first embolic device <NUM> and the second embolic device <NUM>. For example, one component of the interconnect element <NUM> can be a loop formed at a distal or proximal end of the first embolic device <NUM> (e.g., of unitary construction or integral with the first embolic device <NUM>) and another component of the interconnect element <NUM> can be a loop formed at a distal or proximal end of the second embolic device <NUM> (e.g., of unitary construction or integral with the second embolic device <NUM>). In other instances, the interconnect element <NUM> is not of unitary construction or integral with either the first embolic device <NUM> or the second embolic device <NUM> (i.e., the interconnect element is of non-unitary construction or of non-monolithic construction or non-integral with each of the first and second embolic devices <NUM>, <NUM>) and is, instead, fastened, adhered, and/or attached to the first and second embolic devices <NUM>, <NUM>. In other instances, the interconnect element <NUM> is of unitary construction or integral with one of the first and second embolic devices <NUM>, <NUM>, and of non-unitary construction or of non-monolithic construction or non-integral with the other embolic device. In various embodiments, regardless of the particular structure employed, two of the first embolic device <NUM>, the second embolic device <NUM>, and the interconnect element <NUM> are of non-unitary construction with each other.

<FIG> are pictures showing different views of example interconnect elements <NUM>. <FIG> depict an example interconnect element <NUM> formed from two linked loops. <FIG> depicts an example interconnect element <NUM> formed from two linked loops covered by a nitinol coil (e.g., a different coil than the first and second embolic devices <NUM>, <NUM>). In some embodiments, the interconnect element <NUM> can include a nitinol coil by itself not covering another interconnect element. As shown in <FIG>, in some instances in which the interconnect element <NUM> includes a nitinol coil, the nitinol coil is adhered to the first and second embolic devices <NUM>, <NUM>. In general, the nitinol coil (or any other interconnect structure adhered to one or both of the embolic devices <NUM>, <NUM>) can be adhered to one or both of the embolic devices <NUM>, <NUM> using any known technique. In some implementations, a desirable adhesion technique features adequate material biocompatibility and strength, while minimizing the length required to produce end-to-end fixation between the interconnect element <NUM> and the embolic devices <NUM>, <NUM> (which, in some cases, create lengths of unwanted stiffness). As one example, a solder (e.g., gold, silver, or other desirable solder material) can be used to adhere the nitinol coil interconnect element <NUM> to the embolic devices <NUM>, <NUM>. Other example adhesion techniques include (but are not limited to) use of adhesives, welding (e.g., laser, arc, spot), brazing, diffusion bonding, etc..

<FIG> is a picture showing an example multi-stage embolic device <NUM> delivered within a model aneurysm <NUM>. In certain instances, the interconnect element <NUM> joins two elements that are delivered to the vascular disorder and intended to remain at the vascular disorder for a treatment period beyond the delivery. In such instances, the interconnect element <NUM> does not join an embolic device to a device used for delivering the embolic device to the vascular disorder (e.g., a microcatheter or a delivery pusher).

In various embodiments, more than two embolic devices can be joined together, for example, in parallel using more than one interconnect element. Alternatively, more than two embolic devices can be joined together in series using more than one interconnect element (e.g., up to one less than the number of embolic devices). Combinations of series and parallel arrangements are also contemplated. In general, any number of embolic devices can be joined, e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc. As shown in <FIG>, the embolic device <NUM> can include a first embolic device <NUM> joined in series to a second embolic device <NUM> with a first interconnect element 1006a and the second embolic device <NUM> joined in series to a third embolic device <NUM> with a second interconnect element 1006b. In general, the third embolic device <NUM> can take any form (as can any additional embolic device). For example, the third embolic device <NUM> can be a finishing device that further fills the interior cavity of the aneurysm. In various instances, the third embolic device <NUM> (and any additional embolic device) can form any of the particular shapes described above, e.g., spiral shape, infinity shape, etc., or it can take a random or non-geometric shape. The third embolic device <NUM> (and any additional embolic device) can be located in an any location within or around the aneurysm.

In various embodiments, each of the embolic devices (e.g., <NUM>, <NUM>, <NUM>) of the multi-stage embolic device <NUM> can have different properties and behave differently from each other. In general, any embolic device property can be variable amongst the embolic devices. For example, some or all of the embolic devices can have different sizes, shapes, lengths, stiffness, porosity, etc. In other instances, some of all of the embolic devices can have the same of some or all properties. This customizable and independent nature of the embolic device properties can enable operators (e.g., physicians) greater freedom to shape and control coil deployment and positioning than with conventional devices. As one example, an operator can deliver a coil such that it is initially positioned in a first direction and then pivots to be positioned in a different direction at an angle (e.g., <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, etc.) to the first direction.

As mentioned above, in various embodiments, the embolic devices described herein can include a structure (e.g., microcoil, flat sheet, thin film, etc.) covered by a cover element or not covered by a cover element. With reference to the multi-stage embolic device <NUM>, in various embodiments, any, none, or all of the individual embolic devices (e.g., <NUM>, <NUM>, <NUM>, etc.) can be covered or not covered by a cover element.

Claim 1:
A multi-stage embolic device (<NUM>) for use in treating a vascular disorder, the multi-stage embolic device comprising:
a first embolic device (<NUM>);
a second embolic device (<NUM>) different from the first embolic device (<NUM>);
a hook and loop interconnect element (<NUM>) joining the first (<NUM>) and second (<NUM>) embolic devices permitting relative positioning of each embolic device (<NUM>, <NUM>) while they remain joined together; and
a nitinol coil disposed over the hook and loop interconnect element (<NUM>) and adhered to the first embolic device (<NUM>) and the second (<NUM>) embolic device,
wherein at least one of the first (<NUM>) and second (<NUM>) embolic devices comprises a series of alternating narrow portions (<NUM>) and link portions (<NUM>), each link portion (<NUM>) circumscribing an opening in at least one plane, and
wherein each of the first embolic device (<NUM>) and the second embolic device (<NUM>) comprises at least one of a coil, a flat sheet, a thin film, or combinations thereof.