Patent Description:
The present technology relates generally to methods and devices for diverting blood flow in a blood vessel, and particularly to inhibiting blood flow into an aneurysm. Some embodiments of the present technology relate to flow-diverting devices including a plurality of interconnected struts.

Aneurysms are an abnormal bulging or ballooning of a blood vessel that can result from the vessel wall being weakened by disease, injury, or a congenital abnormality. Aneurysms have thin, weak walls and have a tendency to rupture, which can lead to stroke, death, disability, etc. One method of treating aneurysms includes inserting a flow-diverting stent or braid into a parent vessel that includes the aneurysm to be treated. Such stents or braids can be inserted into a vessel in a collapsed state, positioned next to the neck of the aneurysm, and expanded into apposition with the vessel wall. If the stent or braid has a sufficiently low porosity, it can function to block the flow of blood through the device and into the aneurysm to induce embolization of the aneurysm.

However, some aneurysms-and especially cerebral aneurysms—are located in small and tortuous portions of the vasculature. Current designs for flow-diverting stents or braids have difficulty achieving a snug fit across the neck of the aneurysm if the parent vessel is curved, twisted, or forked. For example, current designs generally suffer from crimping or kinking when positioned in such tortuous vessels. This can make it more difficult to position a flow-diverting device and can cause the device to have an inadequate porosity as the device is expanded within the vessel. Also, current designs often undesirably block blood flow to branching or secondary vessels that are close to the aneurysm. Accordingly, there exists a need for improved flow-diverting devices for treating aneurysms. <CIT> discloses a stent having distal and proximal ends with loops including marker members for visualizing the position of the stent. <CIT> discloses a self-expandable vascular and bodily duct treatment device. <CIT> discloses an occlusive device suitable for endovascular treatment of an aneurysm in a region of a parent vessel. <CIT> describes an implant that can include a frame and a mesh component coupled to the frame.

Expandable devices can be delivered into vascular system to divert flow. According to some embodiments, expandable devices are provided for treating aneurysms by diverting flow. A flow-diverting expandable device can comprise a plurality of struts and configured to be implanted in a blood vessel. The expandable device can be expandable to an expanded state at an aneurysm. The expandable device can have at least a section for spanning the neck of the aneurysm and a plurality of pores located between the struts. The expandable device can have a sidewall and a plurality of pores in the sidewall that are sized to inhibit flow of blood through the sidewall into an aneurysm to a degree sufficient to lead to thrombosis and healing of the aneurysm when the expandable device is positioned in a blood vessel and adjacent to the aneurysm.

According to some embodiments not of the present invention, the expandable device can include a frame comprising a plurality of interconnected frame struts forming frame cells and a flow-diverting mesh extending over at least a portion of a length and circumference of the frame. The frame and the flow-diverting mesh can be of a single material and/or monolithic piece.

In some embodiments not of the present invention, a delivery system for treating an aneurysm can comprise a microcatheter configured to be implanted into a blood vessel, a delivery wire extending within the microcatheter and having a distal segment, and the expandable device extending distally from the delivery wire distal segment.

In some embodiments not of the present invention, a flow-diverting device can be configured to be implanted in a blood vessel and can be expandable to an expanded state at the aneurysm. The flow-diverting device can comprise a frame and a mesh fixed to and extending across at least some of the frame. The flow-diverting device can be configured such that the mesh spans the neck of the aneurysm when the flow-diverting device is positioned in a blood vessel and adjacent to the aneurysm. The mesh can further have a porosity and/or pore size configured to interfere with blood flow to a degree sufficient to lead to thrombosis and healing of the aneurysm. An aspect of at least some of the embodiments disclosed herein that do not form part of the present invention involves an expandable structure formed of a plurality of interconnected frame struts forming a plurality of frame cells and a plurality of interconnected mesh struts forming a plurality of mesh cells. The mesh struts can be configured to be flexible so that any tendency of the mesh to inhibit or affect the mechanical performance of the frame, or for the frame to tear or distort the mesh, can be reduced or eliminated. The flow-diverting device can therefore exhibit a high degree of flexibility such that when the device is placed along a sharp turn in a tubular structure, the shape of the device conforms to the turn radius at the sharp turn while remaining in apposition with the inner walls of the tubular structure.

The subject technology is illustrated, for example, according to various aspects described below.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the present technology.

The accompanying drawings, which are included to provide further understanding of the subject technology and are incorporated in and constitute a part of this description, illustrate aspects of the subject technology and, together with the specification, serve to explain principles of the subject technology.

In the following detailed description, specific details are set forth to provide an understanding of the present technology. However, the present technology may be practiced without some of these specific details. In some instances, well-known structures and techniques have not been shown in detail so as not to obscure the present technology.

The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the disclosure. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.

Aspects of the present disclosure are directed generally toward devices that can be delivered into a vascular system to divert flow. According to some embodiments, such devices are provided for treating aneurysms by diverting flow. For example, a device according to the present technology can be configured to interfere with blood flow to generally reduce the exchange of blood between a parent vessel and an aneurysm, which can induce thrombosis of the aneurysm. A device (or a device component, such as a frame and/or mesh) that interferes with blood flow can be said to have a "flow diverting" property.

<FIG> is a plan view of an expandable flow-diverting device <NUM> ("device <NUM>") in an uncurled or laid-flat configuration. As shown in <FIG>, the device <NUM> includes a frame <NUM> forming a plurality of frame cells <NUM>, and a flow-diverting mesh <NUM> ("mesh <NUM>") extending across at least some of the frame cells <NUM>. The frame <NUM> includes longitudinal edges <NUM> and <NUM>. <FIG> is a schematic illustration of the device <NUM> of <FIG> showing the device <NUM> in a tubular configuration and coupled to a delivery wire <NUM> via connector <NUM>. As demonstrated by <FIG> and <FIG>, the frame <NUM> may be configured to curl up from the laid-flat configuration (<FIG>) into the tubular configuration (<FIG>) such that longitudinal edges <NUM> and <NUM> (not shown in <FIG>) are positioned adjacent to or in contact with one another and the frame <NUM> surrounds a lumen extending between open ends of the device <NUM>. In some embodiments, the longitudinal edges <NUM> and <NUM> may overlap when the device <NUM> is in the tubular configuration. While the views provided in several of the figures provided herein show expandable devices laid flat for ease of explanation and understanding, the devices can be formed into a tubular shape. Also, as used herein, the term "longitudinal" can refer to a direction along an axis that extends through the lumen of the device while in a tubular configuration, and the term "circumferential" can refer to a direction along an axis that is orthogonal to the longitudinal axis and extends around the circumference of the device when in a tubular configuration.

In the embodiment shown in <FIG>, the mesh <NUM> extends across all of the frame cells <NUM> in a distal portion <NUM> of the device <NUM>, and is not disposed on or across any of the frame cells <NUM> in a proximal portion <NUM> of the device <NUM>. The proximal portion <NUM> may include one or more tapered sections with frame cells <NUM> that have a different size than the individual frame cells <NUM> of the distal portion <NUM>. For example, as illustrated in <FIG>, individual frame cells 150a in the proximal portion <NUM> can have a longitudinal length that is longer than individual frame cells 150b in the distal portion <NUM>. Accordingly, the frame cells <NUM> can comprise at least two different shapes and/or sizes. In some embodiments, the distal portion <NUM> and/or proximal portion <NUM> can each include frame cells <NUM> having at least two different shapes and/or sizes.

The proximal portion <NUM> may taper gradually towards a connector <NUM>, or some other connection point along the device <NUM> that connects the device <NUM> to a delivery wire (e.g., as shown in <FIG>). The connector <NUM> permits the device <NUM> to be released from the delivery wire within a vessel. In some embodiments, the connector <NUM> may include an electrolytically severable region that corrodes or dissolves under the influence of electrical energy when in contact with an electrolyte. Where an electrolytically severable connection is employed, the device <NUM> may be isolated from electric current such that during detachment of the device <NUM>, only the electrolytically severable region of the connector <NUM> disintegrates in blood, and the device <NUM> separates from the delivery wire cleanly at the electrolytically severable region. In other embodiments, the connector <NUM> can comprise another type of releasable mechanism such as a mechanically releasable connection. In yet other embodiments, the connector <NUM> can comprise a thermally or electrothermally releasable connection that functions by heating and melting a connection area.

The device <NUM> is configured to be self-expanding to a relaxed state or an expanded state from a compressed state. As used herein, the relaxed state is one to which the device <NUM> will self-expand in the absence of any containment or external forces. The device <NUM> can have a maximum diameter in the relaxed state. As used herein, the expanded state is one to which the device <NUM> is capable of self-expanding in a contained environment, such as within a blood vessel. For example and simplicity of measurement, this expanded state can be one to which the device <NUM> will self-expand within a straight, non-tapering cylindrical tube with an inside diameter that is slightly smaller than the maximum diameter of the device <NUM> in the relaxed state. As used herein, the compressed state is the state of the device <NUM> when in a more contained environment than the expanded state, such as within a catheter. For example and simplicity of measurement, this compressed state can be the state of the device when it is within a straight, non-tapering cylindrical tube with an inside diameter that is significantly smaller than the maximum diameter of the device <NUM> in the relaxed state.

The device <NUM> further includes a first longitudinal edge <NUM> and a second longitudinal edge <NUM>. The first longitudinal edge <NUM> and the second longitudinal edge <NUM> may be connected to each other to form a circumferentially continuous shape by welding, soldering, or otherwise joining the first and second longitudinal edges <NUM> and <NUM>. For example, the first and second longitudinal edges <NUM> and <NUM> can be connected to each other so that the distal portion <NUM> of the device <NUM> has a generally tube-like or substantially cylindrical shape. In other embodiments, the device <NUM> is not circumferentially continuous. For example, the first longitudinal edge <NUM> and the second longitudinal edge <NUM> may be formed by cutting a preformed, etched, or laser-cut tube longitudinally along the length of the tube. Regardless of the manner of forming, the device <NUM> may be rolled or curled such that the first and second longitudinal edges <NUM> and <NUM> overlap one another when the device <NUM> is in the compressed state and/or the expanded state. Upon release from the compressed state (e.g., from within a catheter), the device <NUM> (when configured to be self-expanding) may spring open and attempt to assume the expanded state.

As described in further detail below, the mesh <NUM> and frame <NUM> can each comprise a plurality of interconnected struts. <FIG> depicts a perspective view, and <FIG> depicts a cross-sectional view, of a strut according to some embodiments of the present technology. As shown, the strut has a length, a width, and a thickness. The thickness can be measured as a dimension that is orthogonal to a central axis when the device <NUM> is considered in a tubular shape, or as a dimension that is orthogonal to a plane of the device <NUM> when represented as laid-flat. The length can be measured as a distance extending between ends of a strut, where the ends connect to another structure. The width can be measured as the distance that is generally orthogonal to the length and thickness. The width and length of a strut can contribute to a surface coverage and porosity of the device <NUM>. According to some embodiments, the strut can have a square cross-section. However, the strut may have other suitable cross-sectional shapes, such as rectangular, polygonal, round, ovoid, elliptical, or combinations thereof.

<FIG> is an enlarged plan view of a portion (illustrated by the dashed box B in <FIG>) of the device <NUM> shown in <FIG>. As depicted in <FIG>, the mesh <NUM> extends across only some of the frame cells <NUM> of the frame <NUM>. The mesh <NUM> is fixed relative to the frame <NUM>. For example, the mesh <NUM> can be bonded or coupled to the frame <NUM>, or the mesh <NUM> can be formed monolithically with the frame <NUM>. In some embodiments, the mesh <NUM> is disposed on a radially outer side of the frame <NUM>, such that the mesh <NUM> is placed against a body vessel when the device <NUM> is in the expanded state within the body vessel. In other embodiments, the mesh <NUM> is disposed on a radially inner side of the frame <NUM>. In yet other embodiments, the mesh <NUM> is level with or within individual frame cells <NUM> of the frame <NUM>.

The frame <NUM> includes a plurality of interconnected frame struts <NUM> forming the frame cells <NUM> therebetween. As illustrated in <FIG> and <FIG>, frame cells <NUM> are defined between adjacent ones of the frame struts <NUM>. The frame struts <NUM> can have an undulated shape (e.g., sinusoidal or S-like) and can extend longitudinally across some or all of the distal portion <NUM> of the device <NUM>. The frame struts <NUM> can be connected to each other at or near peaks or troughs of their undulated shape. In other embodiments, the frame struts <NUM> can have any other suitable shape or configuration. The thickness and/or width of the frame struts <NUM> can be equal to or less than <NUM>. For example, the thickness and/or width of the frame struts <NUM> can be <NUM> to <NUM>.

The frame struts <NUM> are configured to facilitate expansion, contraction, elongation, foreshortening, distortion, etc. of the frame <NUM> as the device <NUM> is expanded, contracted, bent, etc. during delivery and deployment. For example, in embodiments where the frame struts <NUM> have a generally S-like shape, the frame struts <NUM> can stretch out (e.g., a distance between peaks and troughs of the frame struts <NUM> can increase) when the device <NUM> is elongated. Conversely, the frame struts <NUM> can compress (e.g., the distance between the peaks and troughs of the frame struts <NUM> can decrease) when the device <NUM> is foreshortened. As the frame struts <NUM> change in shape during delivery and deployment, the frame cells <NUM> correspondingly change in shape. For example, as the frame struts <NUM> that form an individual frame cell <NUM> are stretched, a longitudinal length of the frame cell <NUM> can increase while a circumferential height decreases. Likewise, as the frame struts <NUM> that form an individual frame cell <NUM> are compressed, a circumferential height of the frame cell <NUM> can increase while a longitudinal length decreases. Accordingly, the frame struts <NUM> are configured such that the frame <NUM> is flexible. This permits the device <NUM> to be snuggly placed within tortuous regions of the vasculature (e.g., in vessels that are curved, twisted, forked, etc.).

The mesh <NUM> includes a plurality of interconnected mesh struts (e.g., identified individually as connector struts <NUM> and bridge struts <NUM>) forming mesh cells <NUM>. The mesh struts <NUM> and <NUM> are fixed relative to the frame struts <NUM> and can be connected to the frame <NUM> along some or all of the perimeter of an individual frame cell <NUM> (or of some or all frame cells <NUM>). For example, the mesh struts <NUM> and <NUM> can be secured to or monolithically formed with the frame struts <NUM>. In certain embodiments, the number of mesh cells <NUM> is greater than a number of frame cells <NUM>. The number of mesh cells <NUM> can be <NUM> to <NUM> times greater than the number of frame cells <NUM>. For example, within each frame cell <NUM>, between <NUM> and <NUM> mesh cells <NUM> can be formed. While the flow-diverting mesh <NUM> can extend over or under the frame <NUM>, a mesh cell <NUM> is considered to be within a frame cell <NUM> if any portion of the mesh cell <NUM> extends over or across any portion of the frame cell <NUM>.

A porosity of the device <NUM> can be defined as a ratio of an open surface area of the device <NUM> to a total surface area of the device <NUM>. Accordingly, the mesh <NUM> provides a porosity that is lower than a porosity provided by the frame <NUM> alone. For example, the porosity provided by the mesh <NUM> can be in the range of <NUM>%-<NUM>%. The mesh cells <NUM> can provide a pore size that is smaller than a pore size provided by the frame cells <NUM>. That is, the mesh cells <NUM> enclose an area that is less than the frame cells <NUM> (e.g., as measured via a maximum-inscribed-circle technique). The pore size provided by the mesh cells <NUM> can be between <NUM> and <NUM>.

The mesh <NUM> can comprise the primary flow diverting section of the device <NUM>. When the device <NUM> is positioned with a body vessel, the mesh <NUM> can provide embolic properties that interfere with blood flow in or into the body space (e.g., an aneurysm) in or across which the device <NUM> is deployed. Specifically, the porosity and/or pore size of the mesh <NUM> of the device <NUM> can be configured to, for example, interfere with blood flow to a degree sufficient to lead to thrombosis of the aneurysm or other body space.

As shown in <FIG>, the mesh <NUM> includes a plurality of connector struts <NUM> extending across individual frame cells <NUM>. The connector struts <NUM> can be connected to the frame <NUM> at one or more positions along the perimeter of an individual frame cell <NUM>. As shown in the embodiment of <FIG>, opposing longitudinal ends of the connector struts <NUM> can be connected to adjacent frame struts <NUM> that form the corresponding frame cell <NUM>. In some embodiments, the connector struts <NUM> can further be connected to other connector struts <NUM> to form bands or columns that extend along some or all of a circumference of the device <NUM> when the device <NUM> forms a tubular shape. The connector struts <NUM> can have a periodic, undulated, and/or "zigzag" shape. In certain embodiments, the connector struts <NUM> have the same or a generally similar shape as the frame struts <NUM>. The thickness and/or width of the connector struts <NUM> can be equal to or less than <NUM>, for example <NUM>. In some embodiments, the connector struts <NUM> can alternate in width along their length. For example, <FIG> illustrates connector struts <NUM> that alternate between relatively wide and relatively narrow along their length.

In the embodiment illustrated in <FIG> and <FIG>, the mesh <NUM> further comprises a plurality of bridge struts <NUM>. One or more bridge struts <NUM> can connect adjacent ones of the connector struts <NUM>. For example, opposing longitudinal ends of the bridge struts <NUM> can be connected to adjacent connector struts <NUM>. Similarly, one or more bridge struts <NUM> can connect adjacent ones of the frame struts <NUM> and/or connect individual connector struts <NUM> to a corresponding bridge strut <NUM>. The connector struts <NUM> and bridge struts <NUM> together form the plurality of mesh cells <NUM>. The shape of the mesh cells <NUM> depends on the shape and configuration of the connector struts <NUM> and bridge struts <NUM>. The thickness and/or width of the bridge struts <NUM> can be equal to or less than <NUM>, for example <NUM>. In other embodiments, the mesh <NUM> does not include bridge struts <NUM> and only comprises the connector struts <NUM>.

The bridge struts <NUM> generally extend longitudinally along the device <NUM> between adjacent connector struts <NUM> and have a shape including two curved sections (e.g., forming an S-like shape). In other embodiments, the bridge struts <NUM> can have other suitable shapes (e.g., sinusoidal, periodic, linear, z-shaped, etc.). <FIG> illustrates the mesh <NUM> in a state in which the bridge struts <NUM> extend circumferentially to a lesser degree than they do longitudinally (e.g., the bridge struts extend longitudinally further than they extend circumferentially). In other states, the bridge struts <NUM> can extend circumferentially more or equally to the degree they extend longitudinally. As explained in more detail below, the bridge struts <NUM> are flexible to permit elongation and foreshortening of the mesh <NUM>, as necessary, during compression, expansion, or bending of the device <NUM> that occurs during delivery and deployment.

<FIG> is an enlarged plan view of a portion (illustrated by the dashed box C) of the device <NUM> shown in <FIG>, and showing the mesh <NUM> in a different, more elongated state than illustrated in <FIG>. Such a state may occur when the device <NUM> is delivered or deployed into tortuous regions of the vasculature. As shown, the bridge struts <NUM> extend longitudinally to a greater degree and extend circumferentially to a lesser degree than in the state illustrated in <FIG>. Moreover, the bridge struts <NUM> can have a more elongated S-like shape in which the curved sections are relatively more flattened. At the same time, the connector struts <NUM> can have a more compressed shape in which the distance between peaks and/or troughs (e.g., troughs <NUM>) of the undulated connector struts <NUM> are closer together than in the state illustrated in <FIG>.

Conversely, the mesh <NUM> is also configured to accommodate foreshortening of the device <NUM>. For example, in contrast to the state shown in <FIG>, the bridge struts <NUM> can extend circumferentially to a greater degree and extend longitudinally to a lesser degree to accommodate foreshortening of the device <NUM>. Likewise, the connector struts <NUM> can take on a more expanded shape as, for example, the distance between troughs <NUM> increases. As the shape of the connector struts <NUM> and bridge struts <NUM> change, the shape of the mesh cells <NUM> correspondingly change. For example, when the mesh <NUM> is in an elongated state such as that shown in <FIG>, the mesh cells <NUM> can have a longitudinal length that is greater, and a circumferential height that is less, than in the state shown in <FIG> or a foreshortened state.

Moreover, in certain embodiments, instead of or in addition to employing an S-like shape for the bridge struts <NUM>, one or both ends of the bridge struts <NUM> can connect to the trough of an adjacent connector strut <NUM>. For example, as depicted in <FIG>, the individual bridge struts <NUM> are connected to corresponding troughs <NUM> of the individual connector struts <NUM>. The bridge struts <NUM> can therefore be made longer-and accordingly better able to elongate or foreshorten-without requiring an increase in the distance between adjacent connector struts <NUM>. This permits the mesh <NUM> to retain a low porosity while also being made more flexible.

Accordingly, the mesh <NUM> is configured to be flexible and to accommodate compression, expansion, elongation, foreshortening, and/or bending of the device <NUM> during delivery and deployment. As described above, the frame <NUM> is also configured to be flexible so that the device <NUM> can be snuggly placed within tortuous regions of the vasculature (e.g., in vessels that are curved, twisted, forked, etc.). The mesh <NUM> and frame <NUM> are therefore independently flexible while still being immovably attached to each other. Importantly, because the mesh <NUM> can accommodate elongation, foreshortening, etc., in the manner described above, any tendency of the mesh <NUM> to inhibit or affect the mechanical performance of the frame <NUM>, or for the frame <NUM> to tear or distort the mesh <NUM>, can be reduced or eliminated. The device <NUM> can therefore exhibit a high degree of flexibility that allows it to be placed in tortuous regions of the vasculature, while also including a flow-diverting mesh <NUM> that retains a sufficiently small pore size to treat aneurysms therein.

Moreover, the flexibility of the device <NUM> can facilitate accurate placement of the device <NUM> within the vasculature-compared to other commercially available devices, including braided devices. In certain embodiments, some or all of the frame struts <NUM> can comprise a radiopaque marker. The radiopaque marker can be disposed on a substantially straight section of a frame strut <NUM> so that the radiopaque marker is predominantly not subject to bending or flexing. The radiopaque marker can extend from a frame strut <NUM> into a frame cell <NUM> and/or a mesh cell <NUM>. One or more mesh struts <NUM> or <NUM> can be omitted from a pattern to accommodate the presence of the radiopaque marker. The radiopaque marker can be formed on the frame struts <NUM> by a process that is the same or different than a process used to form the frame <NUM> and/or the mesh <NUM>, as discussed further herein.

The device <NUM> can be advantageously placed in a body vessel to treat an aneurysm therein. For example, the device <NUM> can be positioned so that the mesh <NUM> is placed across the neck of the aneurysm to impede blood flow along an aneurysmal flow path between the prevailing direction of arterial flow and the interior of the aneurysm. The device <NUM> can therefore facilitate endothelial growth across the neck of the aneurysm or otherwise across the aneurysmal flow path. Moreover, the device <NUM> can have a thickness that is small enough to enable placement in smaller blood vessels, thereby opening new areas of treatment for flow diversion.

According to some embodiments, struts of a flow-diverting mesh can form a pattern other than that shown in <FIG>, <FIG>, and <FIG>. The shape and size of mesh cells can be altered while still providing a flow-diverting function when placed over an opening in a body vessel, such as an ostium of an aneurysm. For example as shown in <FIG>, a device <NUM> may include a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> may taper gradually towards a connector <NUM>. The device <NUM> can further comprise a frame <NUM> including a plurality of interconnected frame struts <NUM> forming frame cells <NUM> between the frame struts <NUM>. A mesh <NUM> can extend across a portion of the frame cells <NUM>. Features of the device <NUM> that are identified with reference numerals that differ from the reference numerals for the device <NUM> by a multiple of <NUM> can have the same aspects as the corresponding features in the device <NUM>, unless noted otherwise.

<FIG> is an enlarged plan view of a portion of the device <NUM> shown in <FIG>. As illustrated in <FIG>, the mesh <NUM> can comprise a plurality of interconnected mesh struts (e.g., connector struts <NUM> and bridge struts <NUM>) forming mesh cells <NUM>. Opposing longitudinal ends of the connector struts <NUM> can be connected to the perimeter of an individual frame cell <NUM>. For example, as shown in <FIG>, individual connector struts <NUM> can be connected to adjacent frame struts <NUM> that form a corresponding frame cell <NUM>. In some embodiments, the connector struts <NUM> can further be connected to other connector struts <NUM> to form bands or columns that extend along some or all of a circumference of the device <NUM> when the device <NUM> forms a tubular shape. The connector struts <NUM> can have a saw-tooth-like shape and can be interconnected at a plurality of vertices <NUM>. A plurality of mesh cells 265a formed between connector struts <NUM> can have a generally diamond-like shape, thereby forming bands or columns of diamond-shaped mesh cells 265a.

The mesh <NUM> further comprises a plurality of bridge struts <NUM>. One or more bridge struts <NUM> can connect adjacent ones of the connector struts <NUM>. For example, opposing longitudinal ends of the bridge struts <NUM> can be connected to adjacent connector struts <NUM>. The bridge struts <NUM> and connector struts <NUM> can combine to form a plurality of mesh cells 265b that have a different shape from the mesh cells 265a. For example, the mesh cells 265b can have a generally hourglass-like or other shape.

As depicted in <FIG>, the bridge struts <NUM> can extend longitudinally along the device <NUM> between adjacent connector struts <NUM> and have a shape including two curved sections (e.g., forming an S-like shape). The bridge struts <NUM> can extend circumferentially to a lesser or greater degree than they do longitudinally to facilitate elongation and foreshortening of the bridge struts <NUM>, as necessary, during compression, expansion, bending, etc., of the device <NUM>. In some embodiments, the connector struts <NUM> can have a more compressed shape (e.g., forming diamond-shaped mesh cells <NUM> with a greater longitudinal length than circumferential height) than the embodiment illustrated in <FIG>, when the device <NUM> is compressed, expanded, or bent. Thus the mesh <NUM> can accommodate compression, expansion, bending, etc. of the device <NUM> during delivery and deployment. Because the mesh <NUM> can accommodate elongation, foreshortening, etc. in the manner described above, any tendency of the mesh <NUM> to inhibit or affect the mechanical performance of the frame <NUM>, or for the frame <NUM> to tear or distort the mesh <NUM>, can be advantageously reduced or eliminated. The device <NUM> can therefore exhibit a high degree of flexibility that allows it to be placed in tortuous regions of the vasculature, while also including a flow-diverting mesh <NUM> that retains a sufficiently small pore size to treat aneurysms therein.

Instead of or in addition to such an S-shaped bridge strut <NUM>, one or both ends of the bridge struts <NUM> can connect to an adjacent connector strut <NUM> at or near a vertex <NUM> of the connector struts <NUM>. For example, <FIG> illustrates an embodiment in which the bridge struts <NUM> are connected to the vertices <NUM> of the connector struts <NUM>. The bridge struts <NUM> can therefore be made longer-and accordingly better able to elongate or foreshorten-without the need to increase the distance between adjacent connector struts <NUM>.

According to some embodiments, struts of a flow-diverting mesh can form a pattern that is similar to the pattern of struts that form a frame. The shape of frame cells and mesh cells can be the same or similar, while the size of the mesh cells are substantially smaller than that of the frame cells. For example, <FIG> shows a device <NUM> including a frame <NUM> and a flow-diverting mesh <NUM> having a similar pattern, but made on a smaller scale. The device <NUM> includes a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> may taper gradually towards a connector <NUM>. The frame <NUM> includes a plurality of interconnected frame struts <NUM> forming frame cells <NUM> between the frame struts <NUM>. The frame struts <NUM> can have an undulated shape (e.g., sinusoidal or comprising S-curves) and can extend longitudinally across some or all of the distal portion <NUM> of the device <NUM>. The mesh <NUM> can extend across a portion of the frame cells <NUM>. Features of the device <NUM> that are identified with reference numerals that differ from the reference numerals for the device <NUM> by a multiple of <NUM> can have the same aspects as the corresponding features in the device <NUM>, unless noted otherwise.

<FIG> is an enlarged plan view of a portion of the device <NUM> shown in <FIG>. As illustrated in <FIG>, the mesh <NUM> can comprise a plurality of interconnected mesh struts <NUM> forming mesh cells <NUM> therebetween. The mesh struts <NUM> can have an undulated shape (e.g., sinusoidal or comprising S-curves). Individual mesh struts <NUM> extend longitudinally across a corresponding frame cell <NUM> and are connected to the perimeter of the corresponding frame cell <NUM>. The mesh struts <NUM> can be connected to each other at or near peaks or troughs thereof. In the embodiment illustrated in <FIG>, the mesh <NUM> does not include bridge struts. In some embodiments, the mesh may include a plurality of bridge struts extending between and connecting the mesh struts <NUM>. In certain embodiments, bridge struts can extend circumferentially to a greater degree than they extend longitudinally to connect adjacent mesh struts <NUM>.

In some embodiments, at least a portion of the mesh <NUM> can have the same shape as the frame <NUM>. For example, the mesh struts <NUM> and the mesh cells <NUM> can have the same shape as the frame struts <NUM> and the frame cells <NUM>, respectively. However, the mesh struts <NUM> and the mesh cells <NUM> can have a size that is different than that of the frame struts <NUM> and the frame cells <NUM>, respectively. Accordingly, the pattern of the mesh <NUM> can be a small-scaled pattern of the frame <NUM>. In some embodiments, the mesh <NUM> is bonded to, coupled to, or formed monolithically with the frame <NUM> in such a manner that the mesh struts <NUM> are fixed relative to (or secured to) the frame struts <NUM> along some or all of the perimeter of an individual frame cell <NUM> (or of some or all frame cells <NUM>). In such an embodiment, employing a pattern for the mesh <NUM> that is similar or identical to-but smaller in scale than-that employed for the frame <NUM> permits the mesh <NUM> to mimic the expansion, contraction, elongation, foreshortening, distortion, etc. of the frame cells <NUM> as the device <NUM> is expanded, contracted, bent, etc., during delivery and deployment. Thus, any tendency of the mesh <NUM> to inhibit or affect the mechanical performance of the frame <NUM>, or for the frame <NUM> to tear or distort the mesh <NUM>, can be reduced or eliminated. The device <NUM> can therefore exhibit a high degree of flexibility that allows it to be placed in tortuous regions of the vasculature, while also including a flow-diverting mesh <NUM> that retains a sufficiently small pore size to treat aneurysms therein.

<FIG> illustrates another embodiment of a flow-diverting device configured in accordance with the present technology. The device <NUM> includes include a proximal portion <NUM>, a first distal portion <NUM>, a second distal portion <NUM> (e.g., a flow-diverting portion), and a third distal portion <NUM>. The proximal portion <NUM> may taper gradually towards a connector <NUM>. The device <NUM> can comprise a frame <NUM> and a mesh <NUM> extending across a portion of the frame <NUM>. The frame <NUM> and mesh <NUM> can be configured as in any of the embodiments described above with reference to <FIG>, <FIG> and <FIG>. Features of the device <NUM> that are identified with reference numerals that differ from the reference numerals for the device <NUM> by a multiple of <NUM> can have the same aspects as the corresponding features in the device <NUM>, unless noted otherwise.

In the embodiment shown in <FIG>, the mesh <NUM> can be confined to the second distal portion <NUM>, such that the mesh <NUM> does not extend across any of the frame cells <NUM> in the first distal portion <NUM> or the third distal portion <NUM>. The second distal portion <NUM> can be configured to overlie an aneurysm for flow diversion therapy, while the first distal portion <NUM> and/or the third distal portion <NUM> can overlie a branch vessel to simultaneously allow perfusion to the adjacent branch vessel whose ostium is crossed by a portion of the device <NUM>. That is, the device <NUM> can be advantageously positioned to inhibit blood flow into an aneurysm while not also inhibiting flow to branching or secondary vessels that are close to the aneurysm.

A flow-diverting device configured in accordance with the present technology may be formed, for example, by laser cutting a pre-formed tube or sheet, by interconnecting components (e.g., by laser welding), by vapor deposition techniques, or by combinations thereof. A frame can be formed by the same process as a mesh, or the frame can be formed by a process different than that by which the mesh is formed. The device can be formed using known flexible materials such as nitinol, stainless steel, cobalt-chromium alloys, Elgiloy, magnesium alloys, tungsten, tantalum, platinum, or combinations thereof.

In certain embodiments, a flow-diverting device can be formed by a photolithography process. For example, a substrate can be provided with a base for supporting the formation of the device. The base (e.g., copper) can be used temporarily as a buffer between the substrate and a primary material used to form the frame. After the base is provided on the substrate, the primary material is provided thereon, for example by vapor deposition. The primary material can be provided as a thin film of substantially uniform thickness. The thickness of the primary material can correspond to the desired thickness of the frame, as described herein. Portions of the primary material can be removed to form the structure of the frame. For example, a photomask, based on a strut pattern, can be used to selectively expose portions of the primary material to light and etch the primary material into the desired shape for the frame. Alternatively or in combination, a chemical agent can be used to remove the portions of the primary material that are not protected by a photoresist.

After the primary material is formed into the frame, a secondary material used to form the mesh is provided thereon, for example by vapor deposition. The secondary material can be provided as a thin film of substantially uniform thickness. The thickness of the secondary material can correspond to the desired thickness of the mesh, as described herein. Portions of the secondary material can be removed to form the structure of the mesh, while preserving the structure of the frame. For example, a photomask, based on a strut pattern, can be used to selectively expose portions of the secondary material to light and etch the secondary material into the desired shape for the mesh. Alternatively or in combination, a chemical agent can be used to remove the portions of the secondary material that are not protected by a photoresist.

The base can then be eroded to separate the device (frame and mesh) from the substrate. The device can be further treated to form a desired shape (e.g., tubular) and have the desired heat set and/or shape memory properties.

In other embodiments, a flow-diverting device can be formed by a laser cutting process. The device may be formed by cutting a pattern of struts on a tube or on a flat sheet and then rolling the flat sheet into a generally tube-like or coiled shape. As described above, the device can be can be circumferentially continuous or discontinuous while in a generally tube-like or coiled shape. Where the device is circumferentially discontinuous, portions of the device can overlap in certain states.

In yet other embodiments, the frame can be formed by a laser cutting process, and the mesh can be formed on the frame by vapor deposition and photolithography, as described above.

The present technology also includes methods of treating a vascular condition, such as an aneurysm, with any of the embodiments of the flow-diverting devices disclosed herein. A flow-diverting device according to the present technology can be deployed across the neck of an aneurysm and its flow-diverting properties employed to reduce blood flow between the aneurysm and the parent vessel. By reducing the blood flow to the aneurysm, the blood inside the aneurysm can be caused to thrombose, and to thereby lead to healing of the aneurysm.

In order to implant any of the flow-diverting devices disclosed herein, the device can be mounted in a delivery system. Generally, the delivery system can include an elongate delivery wire that supports or contains the device, and both components can be slidably received in a lumen of a microcatheter or other elongate sheath for delivery to any region to which the distal opening of the microcatheter can be advanced. The delivery wire is employed to advance the device through the microcatheter and out the distal end of the microcatheter so that the device is allowed to self-expand into place in the blood vessel, across an aneurysm or other treatment location. Accordingly, a vascular treatment apparatus can comprise a delivery system and a flow-diverting device, such as any of the devices described herein, mounted in or supported by the delivery system.

A treatment procedure can begin with obtaining percutaneous access to the patient's arterial system, typically via a major blood vessel in a leg or arm. A guidewire can be placed through the percutaneous access point and advanced to the treatment location, which can be in an intracranial artery, or any neurovascular artery, peripheral artery or coronary artery. (As configured for neurovascular use, any of the devices disclosed herein can have a diameter of <NUM>-<NUM> in the relaxed state or the expanded state; devices used in the peripheral or coronary vasculature can have a diameter of <NUM>-<NUM> in the relaxed state or the expanded state. ) The microcatheter is then advanced over the guidewire to the treatment location and situated so that a distal open end of the microcatheter is adjacent to the treatment location. The guidewire can then be withdrawn from the microcatheter. The delivery wire, together with the flow-diverting device mounted thereon or supported thereby, can then be advanced through the microcatheter and out the distal end thereof. The device can then self-expand into apposition with the inner wall of the blood vessel. Where an aneurysm is being treated, the device is placed across the neck of the aneurysm so that a sidewall of the device separates the interior of the aneurysm from the lumen of the parent artery. Once the device has been placed and detached from the delivery wire, the delivery wire and microcatheter are removed from the patient. The device sidewall can now perform a flow-diverting function on the aneurysm, thrombosing the blood in the aneurysm and leading to healing of the aneurysm.

An expandable device comprising a thin film forming a mesh can be used to treat an aneurysm. The expandable device can impede blood flow along an aneurysmal flow path between the prevailing direction of arterial flow and the interior of the aneurysm via, e.g., high pore density, small pore size and/or high material coverage across the aneurysmal flow path, and facilitate endothelial growth across the neck of the aneurysm or otherwise across the aneurysmal flow path. The expandable device can comprise a single component, low profile, high pore density flow diverter of a single material and/or of monolithic construction. The expandable device can facilitate accurate placement by requiring less foreshortening as compared to other commercially available devices, including braided devices. The expandable device can have a thickness that is small enough to enable placement in smaller blood vessels, thereby opening new areas of treatment for flow diversion.

According to some embodiments, an expandable device, such as a stent, can have a flow diverting section or other portion of the device that provides embolic properties so as to interfere with blood flow in (or into) the body space (e.g., an aneurysm) in (or across) which the device is deployed. The sidewall material coverage, porosity and/or pore size of one or more sections of the device can be selected to interfere with blood flow to a degree sufficient to lead to thrombosis of the aneurysm or other body space.

According to some embodiments, the expandable device can be configured to interfere with blood flow to generally reduce the exchange of blood between the parent vessel and an aneurysm, which can induce thrombosis of the aneurysm. A device (or a device component, such as a sidewall of a stent or a section of such a sidewall) that interferes with blood flow can be said to have a "flow diverting" property.

According to some embodiments, a porosity of the expandable device is equal to a ratio of an open surface area of the expandable device to a total surface area of the expandable device. The expandable device may comprise a plurality of struts, which form pores or cells as open areas between the struts.

The device can exhibit a porosity configured to reduce haemodynamic flow into and/or induce thrombosis within an aneurysm. The device can simultaneously allow perfusion to an adjacent branch vessel whose ostium is crossed by a portion of the device. The device can exhibit a high degree of flexibility due to the materials used, the density (i.e., the porosity) of the struts, and the arrangement of struts.

The device is self-expanding to a relaxed state or an expanded state. As used herein, the relaxed state is one to which the expandable device will self-expand in the absence of any containment or external forces. As used herein, expanded state is one to which the expandable device is capable of self-expanding, ignoring any containment, such by as a blood vessel. For example and simplicity of measurement, this expanded state can be one to which the expandable device will self-expand within a straight, non-tapering cylindrical tube with an inside diameter that is slightly smaller than the maximum diameter of the expandable device in the relaxed state.

According to some embodiments, the expandable device may include a plurality of individual struts and individual cells, as well as a first longitudinal edge and a second longitudinal edge. The first longitudinal edge and the second longitudinal edge may be connected to each other to form a substantially cylindrical shape or a circumferentially continuous shape by welding, soldering, or otherwise joining the struts or edges.

According to some embodiments in which the device is not a circumferentially continuous cylinder, the first edge and second edge may be formed, for example, by cutting a preformed, etched or laser-cut tube longitudinally along the length of the tube. Regardless of the manner of forming, the expandable device may be rolled or curled such that the first and second longitudinal edges overlap one another when the expandable device is in a compressed state and/or an expanded state. Upon release from a constraint (e.g. from within a catheter), the expandable device (when configured to be self-expanding) may spring open and attempt to assume an expanded state.

While the views provided in several of the figures (e.g., <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG>) show expandable devices laid flat for ease of explanation and understanding, it will be understood that the devices can possess a tubular shape, and the laid-flat drawings presented herein depict the configuration of a sidewall of the tube. While in the tubular shape, the expandable devices can have open ends of a lumen extending through the expandable device.

According to some embodiments, an expandable device can comprise a frame and a flow-diverting mesh extending over the frame. The frame can provide structural support, and the flow-diverting mesh can provide a flow-diverting function when placed over an opening in a body vessel, such as an ostium of an aneurysm.

According to some embodiments, for example as shown in <FIG>, an expandable device <NUM> may include a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> may include one or more taper sections with cells that have a different size than the individual cells <NUM> of the distal portion <NUM>. The proximal portion <NUM> may taper gradually towards a connection mechanism <NUM>, or some other connection point along the expandable device <NUM> that connects the expandable device <NUM> to a delivery wire (not shown). The connection mechanism <NUM> permits release of the expandable device <NUM>. The connection mechanism <NUM> may include, for example, an electrolytically severable region. While other types of releasable connection mechanisms are also possible (e.g. a mechanically releasable connection or a thermally or electrothermally releasable connection that can function by heating and melting a connection area), in one aspect, the connection mechanism <NUM> comprises a connection that corrodes or dissolves under the influence of electrical energy when in contact with an electrolyte. Where an electrolytically severable connection is employed, the expandable device <NUM> may generally be isolated from electric current, such that during detachment of the expandable device <NUM>, only the electrolytically severable region of the connection mechanism <NUM> disintegrates in blood, and the expandable device <NUM> separates from a delivery wire cleanly at the electrolytically severable region, and is released into the vessel.

According to some embodiments, for example as shown in <FIG>, the expandable device <NUM> can comprise a frame <NUM> and a flow-diverting mesh <NUM> extending over the frame <NUM>. The flow-diverting mesh <NUM> can be disposed on a radially outer side of the frame <NUM>, such that the flow-diverting mesh <NUM> is placed against a body vessel when the expandable device <NUM> is in a tubular shape and expanded within the body vessel. Alternatively, the mesh <NUM> could be disposed on a radially inner side of the frame <NUM>, or level with or sandwiched within the frame <NUM>.

According to some embodiments, the frame <NUM> can comprise a plurality of interconnected frame struts <NUM> forming frame cells <NUM> between the frame struts <NUM>. The frame struts <NUM> can form a series of undulations (e.g., sinusoidal or "S-curves") that extend longitudinally across some or all of the distal portion <NUM> of the expandable device <NUM>. The frame struts <NUM> can be connected to each other at or near peaks or troughs thereof. The thickness and/or width of the frame struts <NUM> can be equal to or less than <NUM>. The thickness and/or width of the frame struts <NUM> can be <NUM> to <NUM>. Any suitable frame configuration can be employed, other than that shown in <FIG> and <FIG>.

According to some embodiments, the flow-diverting mesh <NUM> can comprise a plurality of interconnected mesh struts (e.g., connector struts <NUM> and bridge members <NUM>) forming mesh cells <NUM>. The number of mesh cells <NUM> is greater than a number of frame cells <NUM>. The number of mesh cells <NUM> can be <NUM> to <NUM> times greater than the number of frame cells <NUM>. For example, within each frame cell <NUM>, between <NUM> and <NUM> mesh cells <NUM> can be formed. While the flow-diverting mesh <NUM> can extend over the frame <NUM>, mesh cells <NUM> are considered to be within a frame cell <NUM> if any portion of the mesh cells extends over or across any portion of the frame cell <NUM>. The flow-diverting mesh <NUM> can provide a porosity that is lower than a porosity provided by the frame <NUM> alone. For example, the porosity provided by the flow-diverting mesh <NUM> can be in the range of <NUM>%-<NUM>%. The mesh cells <NUM> can provide a pore size that is smaller than a pore size provided by the frame cells <NUM>. A pore size can be measured via a maximum-inscribed-circle technique. The pore size provided by the mesh cells <NUM> can be between <NUM> and <NUM>.

According to some embodiments, the frame <NUM> can comprise frame cells <NUM> with at least two different shapes and/or sizes. According to some embodiments, the flow-diverting mesh <NUM> can comprise mesh cells <NUM> with at least two different shapes and/or sizes. According to some embodiments, the flow-diverting mesh <NUM> does not extend over any of the proximal portion <NUM>.

According to some embodiments, a series of connector struts <NUM> can connect to each other to extend along some or all of a circumference of the expandable device <NUM> when the expandable device <NUM> forms a tubular shape. In a band or column, the struts <NUM> can be arranged in a "zigzag" pattern as depicted in <FIG> and <FIG>, thereby forming a V-strut band or column. In some embodiments, the struts <NUM> of an individual band or column can alternate in width, e.g. between relatively wide and relatively narrow struts <NUM> as shown in <FIG>. A circumferentially extending band or column of connector struts <NUM> can be connected to the adjacent band(s) or column(s) of connector struts <NUM> by one or more bridge members <NUM>. Some or all of the bridge members <NUM> can be connected to connector struts <NUM> at opposing longitudinal ends of the bridge members <NUM>. As depicted in <FIG>, in one embodiment, the bridge members <NUM> extend longitudinally (but also circumferentially, to a lesser (or greater, or equal) degree than they do longitudinally) from one end connected to one adjacent connector strut <NUM> to an opposing end connected to another adjacent connector strut <NUM>, with two curved sections (e.g., forming an "S" shape). Such a configuration permits elongation and foreshortening of the bridge members <NUM>, as necessary, during compression, expansion or bending of the device <NUM>. Instead of or in addition to such an "S" shape, one or both ends of the bridge member(s) <NUM> can connect to a connector strut <NUM> at a location that is spaced from either longitudinal end of the strut <NUM>, e.g. in a central longitudinal region of the strut <NUM>. The bridge member(s) <NUM> can therefore be made longer, and accordingly better able to elongate or foreshorten, without need to increase the distance between adjacent columns of connector struts <NUM>. Thus the mesh can accommodate compression, expansion, elongation or bending of the device <NUM> during delivery and deployment. Moreover, in some embodiments, the mesh <NUM> is bonded or coupled to, or formed monolithically with, the frame <NUM> in such a manner that the struts <NUM> and/or bridge members <NUM> are immovable relative to (or secured to) the frame struts <NUM> along some or all of the perimeter of an individual frame cell <NUM> (or of some or all frame cells <NUM>). In such an embodiment, the employment of a pattern for the mesh that can accommodate elongation, foreshortening, etc. in this manner facilitates expansion, contraction, elongation, foreshortening, distortion, etc. of the frame cells <NUM> as the device <NUM> is expanded, contracted, bent, etc. during delivery and deployment. Thus any tendency of the mesh <NUM> to inhibit or affect the mechanical performance of the frame <NUM>, or for the frame to tear or distort the mesh, can be reduced or eliminated. The thickness and/or width of the connector struts <NUM> and/or bridge members <NUM> can be equal to or less than <NUM>, for example <NUM>.

<FIG> depicts a perspective view of a strut according to some embodiments of the subject technology. <FIG> depicts a cross-sectional view of a strut or bridge member according to some embodiments of the subject technology. As shown, the connector strut or bridge member has a length, a width, and a thickness. The thickness can be measured as a dimension that is orthogonal to a central axis when the expandable device <NUM> is considered in a tubular shape or as a dimension that is orthogonal to a plane of the expandable device <NUM> when represented as laid-flat. The length can be measured as a distance extending between ends of a strut, where the ends connect to another structure. The width can be measured as the distance that is generally orthogonal to the length and thickness. The width and length of a strut can contribute to a surface coverage and porosity of the expandable device <NUM>. According to some embodiments, the strut can have a square cross-section. However, the strut may have other suitable cross-sectional shapes, such as rectangular, polygonal, round, ovoid, elliptical, or combinations thereof.

According to some embodiments, some or all of the frame struts <NUM> can comprise a radiopaque marker. The radiopaque marker can be disposed on a substantially straight section of a frame strut <NUM>, so the radiopaque marker is predominantly not subject to bending or flexing. The radiopaque marker can extend from a frame strut <NUM> into a frame cell <NUM> and/or a mesh cell <NUM>. One or more mesh struts can be omitted from a pattern to accommodate the presence of the radiopaque marker. The radiopaque marker can be formed on the frame struts <NUM> by a process that is the same or different than a process used to form the frame and/or the mesh, which are discussed further herein.

According to some embodiments, struts of a flow-diverting mesh can form a pattern other than that shown in <FIG> and <FIG>. The shape and size of mesh cells can be altered while still providing a flow-diverting function when placed over an opening in a body vessel, such as an ostium of an aneurysm.

According to some embodiments, for example as shown in <FIG>, an expandable device <NUM> may include a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> may taper gradually towards a connection mechanism <NUM>. According to some embodiments, for example as shown in <FIG>, the expandable device <NUM> can comprise a frame <NUM> and a mesh <NUM> extending over the frame <NUM>. The frame <NUM> can comprise a plurality of interconnected frame struts <NUM> forming frame cells <NUM> between the frame struts <NUM>. The mesh <NUM> can comprise a plurality of interconnected mesh struts (e.g., connector struts <NUM> and bridge members <NUM>) forming mesh cells <NUM>. Features of the expandable device <NUM> that are identified with reference numerals that differ from the reference numerals for the expandable device <NUM> by a multiple of <NUM> can have the same aspects as the corresponding features in the expandable device <NUM>, unless noted otherwise. Any suitable frame configuration can be employed, other than that shown in <FIG>.

According to some embodiments, a series of connector struts <NUM> can connect to each other to extend along some or all of a circumference of the expandable device <NUM>, e.g., in the form of circumferential bands or columns of struts <NUM>, when the expandable device <NUM> forms a tubular shape. Mesh cells <NUM> formed between connector struts <NUM> can be approximately diamond shaped, thereby forming bands or columns of diamond shaped cells. Other mesh cells <NUM> formed at least in part by bridge members <NUM> can have a different shape (e.g., hourglass). A circumferentially extending series, band or column of connector struts <NUM> can be connected to another column of connector struts <NUM> by one or more bridge members <NUM>. Some or all of the bridge members <NUM> can be connected to connector struts <NUM> at opposing longitudinal ends of the bridge members <NUM>. As depicted in <FIG>, in one embodiment, the bridge members <NUM> extend longitudinally (but also circumferentially, to a lesser (or greater, or equal) degree than they do longitudinally) from one end connected to one adjacent connector strut <NUM> to an opposing end connected to another adjacent connecting strut <NUM>, with two curved sections (e.g., forming an "S" shape). Such a configuration permits elongation and foreshortening of the bridge members <NUM>, as necessary, during compression, expansion or bending of the device <NUM>. Instead of or in addition to such an "S" shape, one or both ends of the bridge member(s) <NUM> can connect to a connector strut column at a location that is spaced from either longitudinal end of the column, e.g. in a central longitudinal region of the column. The bridge member(s) <NUM> can therefore be made longer, and accordingly better able to elongate or foreshorten, without need to increase the distance between adjacent columns of connector struts <NUM>. Thus the mesh can accommodate compression, expansion, elongation or bending of the device <NUM> during delivery and deployment. Moreover, in some embodiments, the mesh <NUM> is bonded or coupled to, or formed monolithically with, the frame <NUM> in such a manner that the struts <NUM> and/or bridge members <NUM> are immovable relative to (or secured to) the frame struts <NUM> along some or all of the perimeter of an individual frame cell <NUM> (or of some or all frame cells <NUM>). In such an embodiment, the employment of a pattern for the mesh that can accommodate elongation, foreshortening, etc. in this manner facilitates expansion, contraction, elongation, foreshortening, distortion, etc. of the frame cells <NUM> as the device <NUM> is expanded, contracted, bent, etc. during delivery and deployment. Thus any tendency of the mesh <NUM> to inhibit or affect the mechanical performance of the frame <NUM>, or for the frame to tear or distort the mesh, can be reduced or eliminated.

According to some embodiments, struts of a flow-diverting mesh can form a pattern that is similar to the pattern of struts that form a frame. The shape of frame cells and mesh cells can be the same or similar, while the size of the mesh cells are substantially smaller than that of the frame cells. For example, the pattern of the flow-diverting mesh can be the same as that of the frame, but made on a smaller scale.

According to some embodiments, for example as shown in <FIG>, an expandable device <NUM> may include a proximal portion <NUM>, a first distal portion <NUM>, a second distal portion <NUM> (e.g., flow diverting portion), and a third distal portion <NUM>. The proximal portion <NUM> may taper gradually towards a connection mechanism <NUM>. According to some embodiments, for example as shown in <FIG>, the expandable device <NUM> can comprise a frame <NUM> and a mesh <NUM> extending over the frame <NUM>. The frame <NUM> can comprise a plurality of interconnected frame struts <NUM> forming frame cells <NUM> between the frame struts <NUM>. The mesh <NUM> can comprise a plurality of interconnected mesh struts <NUM> forming mesh cells <NUM>. Features of the expandable device <NUM> that are identified with reference numerals that differ from the reference numerals for the expandable device <NUM> by a multiple of <NUM> can have the same aspects as the corresponding features in the expandable device <NUM>, unless noted otherwise. Any suitable frame configuration can be employed, other than that shown in <FIG>.

With reference to <FIG>, according to some embodiments, the mesh <NUM> can be confined to the second distal portion <NUM>, such that the mesh <NUM> does not extend over the first distal portion <NUM> or the third distal portion <NUM>. The second distal portion <NUM> can be designed to overlie an aneurysm for flow diversion therapy, while the first distal portion <NUM> and/or the third distal portion <NUM> can overlie a branch vessel to allow perfusion thereto.

With reference to <FIG>, according to some embodiments, at least a portion of the mesh <NUM> can have the same shape as the frame <NUM>. For example, the mesh struts <NUM> and the mesh cells <NUM> can have the same shape as the frame struts <NUM> and the frame cells <NUM>, respectively. However, the mesh struts <NUM> and the mesh cells <NUM> can have a size that is different than that or the frame struts <NUM> and the frame cells <NUM>, respectively. Accordingly, the pattern of the mesh <NUM> can be a small-scaled pattern of the frame <NUM>. In some embodiments, the mesh <NUM> is bonded or coupled to, or formed monolithically with, the frame <NUM> in such a manner that the mesh struts <NUM> are immovable relative to (or secured to) the frame struts <NUM> along some or all of the perimeter of an individual frame cell <NUM> (or of some or all frame cells <NUM>). In such an embodiment, the employment of a pattern for the mesh that is similar or identical to, but smaller in scale than, that employed for the frame permits the mesh to mimic the expansion, contraction, elongation, foreshortening, distortion, etc. of the frame cells <NUM> as the device <NUM> is expanded, contracted, bent, etc. during delivery and deployment. Thus any tendency of the mesh <NUM> to inhibit or affect the mechanical performance of the frame <NUM>, or for the frame to tear or distort the mesh, can be reduced or eliminated.

According to some embodiments, the mesh struts <NUM> can form a series of undulations (e.g., sinusoidal or "S-curves") that extend longitudinally across the some or all of the second distal portion <NUM> of the expandable device <NUM>. The mesh struts <NUM> can be connected to each other at or near peaks or troughs thereof.

An expandable device may be formed, for example, by laser cutting a pre-formed tube or sheet, by interconnecting components (e.g., by laser welding), by vapor deposition techniques, or combinations thereof. A frame can be formed by the same process as a mesh, or the frame can be formed by a process different than that by which the mesh is formed. The expandable device can be formed using known flexible materials such as nitinol, stainless steel, cobalt-chromium alloys, Elgiloy, magnesium alloys, tungsten, tantalum, platinum, or combinations thereof.

According to some embodiments, an expandable device can be formed by a photolithography process. A substrate can be provided with a base for supporting the formation of the expandable device. The base (e.g., copper) can be used temporarily as a buffer between the substrate and a primary material used to form the frame. After the base is provided on the substrate, the primary material is provided thereon, for example by vapor deposition. The primary material can be provided as a thin film of substantially uniform thickness. The thickness of the primary material can correspond to the desired thickness of the frame, as described herein. Portions of the primary material can be removed to form the structure of the frame. For example, a photomask, based on a strut pattern, can be used to selectively expose portions of the primary material to light and etch the primary material into the desired shape for the frame. Alternatively or in combination, a chemical agent can be used to remove the portions of the primary material that are not protected by a photoresist.

The base can then be eroded to separate the expandable device (frame and mesh) from the substrate. The expandable device can be further treated to form a desired shape (e.g., tubular) and have the desired heat set and/or shape memory properties.

According to some embodiments, an expandable device can be formed by a laser cutting process. The expandable device may be formed by cutting a pattern of struts on a tube or on a flat sheet and then rolling the flat sheet into a generally tube-like or coiled shape. The expandable device in a generally tube-like or coiled shape can be circumferentially continuous or discontinuous. Where the expandable device is circumferentially discontinuous, portions of the expandable device can overlap in certain states. According to some embodiments, the frame can be formed by a laser cutting process, and the mesh can be formed on the frame by vapor deposition and photolithography, as described above.

As mentioned elsewhere herein, the present disclosure also includes methods of treating a vascular condition, such as an aneurysm, with any of the embodiments of the expandable devices disclosed herein. The expandable device could be deployed across the neck of an aneurysm and its flow-diverting properties employed to reduce blood flow between the aneurysm and the parent vessel, cause the blood inside the aneurysm to thrombose, and lead to healing of the aneurysm.

In order to implant any of the expandable devices disclosed herein, the expandable device can be mounted in a delivery system. Generally, the delivery system can include an elongate delivery wire that supports or contains the expandable device, and both components can be slidably received in a lumen of a microcatheter or other elongate sheath for delivery to any region to which the distal opening of the microcatheter can be advanced. The delivery wire is employed to advance the expandable device through the microcatheter and out the distal end of the microcatheter so that the expandable device is allowed to self-expand into place in the blood vessel, across an aneurysm or other treatment location. Accordingly, a vascular treatment apparatus can comprise a delivery system, such as any of the delivery systems described herein, and an expandable device, such as any of the expandable devices described herein, mounted in or supported by the delivery system.

A treatment procedure can begin with obtaining percutaneous access to the patient's arterial system, typically via a major blood vessel in a leg or arm. A guidewire can be placed through the percutaneous access point and advanced to the treatment location, which can be in an intracranial artery, or any neurovascular artery, peripheral artery or coronary artery. (As configured for neurovascular use, any of the expandable devices disclosed herein can have a diameter of <NUM>-<NUM> in the relaxed state or the expanded state; expandable devices used in the peripheral or coronary vasculature can have a diameter of <NUM>-<NUM> in the relaxed state or the expanded state. ) The microcatheter is then advanced over the guidewire to the treatment location and situated so that a distal open end of the microcatheter is adjacent to the treatment location. The guidewire can then be withdrawn from the microcatheter and the delivery wire, together with the expandable device mounted thereon or supported thereby, can be advanced through the microcatheter and out the distal end thereof. The expandable device can then self-expand into apposition with the inner wall of the blood vessel. Where an aneurysm is being treated, the expandable device is placed across the neck of the aneurysm so that a sidewall of the expandable device separates the interior of the aneurysm from the lumen of the parent artery. Once the expandable device has been placed and detached from the delivery wire, the delivery wire and microcatheter are removed from the patient. The expandable device sidewall can now perform a flow-diverting function on the aneurysm, thrombosing the blood in the aneurysm and leading to healing of the aneurysm.

The foregoing description is provided to enable a person skilled in the art to practice the various configurations described herein. While the subject technology has been particularly described with reference to the various figures and configurations, it should be understood that these are for illustration purposes only and should not be taken as limiting the scope of the subject technology.

There may be many other ways to implement the subject technology. Various functions and elements described herein may be partitioned differently from those shown without departing from the scope of the subject technology. Various modifications to these configurations will be readily apparent to those skilled in the art, and generic principles defined herein may be applied to other configurations. Thus, many changes and modifications may be made to the subject technology, by one having ordinary skill in the art, without departing from the scope of the subject technology.

A phrase such as "an aspect" does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. An aspect may provide one or more examples of the disclosure. A phrase such as "an aspect" may refer to one or more aspects and vice versa. A phrase such as "an embodiment" does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. An embodiment may provide one or more examples of the disclosure. A phrase such "an embodiment" may refer to one or more embodiments and vice versa. A phrase such as "a configuration" does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A configuration may provide one or more examples of the disclosure. A phrase such as "a configuration" may refer to one or more configurations and vice versa.

It is understood that the specific order or hierarchy of steps in the processes disclosed is an illustration of exemplifying approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. Some of the steps may be performed simultaneously. Various methods are disclosed presenting elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

Furthermore, to the extent that the term "include," "have," or the like is used herein, such term is intended to be inclusive in a manner similar to the term "comprise" as "comprise" is interpreted when employed as a transitional word in a claim.

A reference to an element in the singular is not intended to mean "one and only one" unless specifically stated, but rather "one or more. " The term "some" refers to one or more.

Claim 1:
A medical device (<NUM>) comprising:
a frame (<NUM>) including a plurality of interconnected frame struts (<NUM>), a plurality of first frame cells, and a plurality of second frame cells, wherein the plurality of first and second frame cells are formed between adjacent ones of the interconnected frame struts (<NUM>); and
a mesh (<NUM>) including a plurality of interconnected mesh struts (<NUM>,<NUM>) forming a plurality of mesh cells (<NUM>) therebetween, the individual mesh struts (<NUM>,<NUM>) extending across a corresponding one of the first frame cells and connected to the frame (<NUM>) at a perimeter of the corresponding first frame cell,
wherein the plurality of mesh struts (<NUM>,<NUM>) are a plurality of first mesh struts (<NUM>), and
wherein the medical device (<NUM>) comprises a plurality of second mesh struts (<NUM>),
wherein the frame (<NUM>) has a circumference, and wherein the plurality of first mesh struts (<NUM>) extend circumferentially about the frame (<NUM>),
wherein individual second mesh struts (<NUM>) connect to adjacent ones of the first mesh struts (<NUM>), wherein the second mesh struts (<NUM>) have a generally S-like shape and extend longitudinally farther than they extend circumferentially,
and wherein-
the mesh (<NUM>) is fixed relative to the frame (<NUM>),
the mesh (<NUM>) extends across the first frame cells,
the mesh cells (<NUM>) have an area that is less than an area of the frame cells (<NUM>), and
the mesh (<NUM>) is configured to divert the flow of a liquid.