Patent Description:
Vaso-occlusive devices or implants are used for a wide variety of reasons, including treatment of intra-vascular aneurysms. An aneurysm is a dilation of a vessel, such as a blood vessel, that may pose a risk to a patient's health due to rupture, clotting, or dissection. For example, rupture of an aneurysm in a patient's brain may cause a stroke, and lead to brain damage and death. Cerebral aneurysms may be detected in a patient, e.g., following seizure or hemorrhage, and may be treated by applying vaso-occlusive devices.

Commonly used vaso-occlusive devices include soft, helically wound coils formed by winding a platinum (or platinum alloy) wire strand about a "primary" mandrel. The coil is then wrapped around a larger, "secondary" mandrel, and heat treated to impart a secondary shape. For example, <CIT> describes a vaso-occlusive device that assumes a linear, helical primary shape when stretched for placement through the lumen of a delivery catheter, and a folded, convoluted secondary shape when released from the delivery catheter and deposited in the vasculature. In order to better frame and fill aneurysms, complex three-dimensional secondary shapes can be imparted on vaso-occlusive devices and the stiffness/flexibility of vaso-occlusive devices can be modified.

In order to deliver the vaso-occlusive devices to a desired site in the vasculature, e.g., within an aneurysmal sac, it is known to first position a small profile delivery catheter or "micro-catheter" at the site using a guidewire. Typically, the distal end of the micro-catheter is provided, either by the attending physician or by the manufacturer, with a selected pre-shaped bend, e.g., <NUM>°, <NUM>°, "J", "S", or other bending shape, depending on the particular anatomy of the patient, so that it will stay in a desired position for releasing one or more vaso-occlusive device(s) into the aneurysmal sac once the guidewire is withdrawn. A delivery or "pusher" assembly or "wire" is then passed through the micro-catheter until a vaso-occlusive device coupled to a distal end of the delivery assembly is extended out of the distal end opening of the micro-catheter and into the aneurysmal sac. Once in the aneurysmal sac, portions of the vaso-occlusive device may deform or bend to allow more efficient and complete packing. The vaso-occlusive device is then released or "detached" from the distal end of the delivery assembly, and the delivery assembly is withdrawn back through the micro-catheter. Depending on the particular needs of the patient, one or more additional vaso-occlusive devices may be pushed through the micro-catheter and released into the same aneurysmal sac.

Fluoroscopy is typically used to visualize vaso-occlusive devices during delivery into an aneurysm, while magnetic resonance imaging (MRI) is typically used to visualize the treatment site post-procedure (e.g., a few weeks after initial treatment of the aneurysm) to ensure that the aneurysmal sac is properly occluded. As such, it is important that vaso-occlusive devices be constructed in a manner that enables their radiopacity during treatment of the aneurysm, while minimizing any visualization obscuring artifacts created during the post-procedure MRI (i.e., being MRI-compatible). It is also preferable that such vaso-occlusive devices be "soft" (i.e., be laterally flexible or conformable), and thus atraumatic, to prevent rupturing of the delicate tissues of the aneurysm.

It is also important that such vaso-occlusive devices be chronically retained within the aneurysm. However, aneurysms with larger mouths, commonly known as "wide neck aneurysms," present difficulty in the placement and retention of vaso-occlusive devices within the aneurysm sacs, particularly with small and relatively thin vaso-occlusive coils which lack sufficient mechanical strength to maintain their position within such aneurysm sacs no matter how skillfully they are placed. For instance, small aneurysms (e.g., aneurysm having diameters less than about <NUM>, or even smaller such as less than about <NUM>), often have the characteristics of a wide neck and a short dome. More specifically, small aneurysms often have relatively wide necks compared to the size of the aneurysm (i.e., the proportion of the width of the neck to the diameter of the aneurysm is often large for small aneurysms as compared to such proportion for larger aneurysms). Due to the relatively wide neck, small aneurysms (and wide neck aneurysms, in general) have greater risk of coil herniation into the parent vessel both during placement and retention. <FIG> depicts a portion of a vaso-occlusive coil herniating out of the aneurysm after implantation. To alleviate coil herniation during placement, several placement techniques have been developed. One such placement technique, called a "jailing technique," utilizes a balloon or stent deployed in the vessel adjacent to the neck region of the aneurysm to prevent the vaso-occlusive coils from exiting the aneurysmal sac. <FIG> depicts the jailing technique using a balloon activated catheter. The balloon activated catheter is used to deploy a balloon adjacent to the neck region of the aneurysm. The balloon prevents coils from herniating from the aneurysm as the latterare implanted into the aneurysm. However, as depicted in <FIG>, this technique creates a risk of the balloon pushing the tip of the catheter into the dome of the aneurysm and rupturing the aneurysm. <FIG> depicts a jailing technique using a stent. The stent is placed and expanded around the neck of the aneurysm to block the coils from exiting the aneurysm sac. Similar to the balloon activated catheter, the stent technique also risks the stent pushing the tip of the catheter into the dome of the aneurysm and rupturing the aneurysm. <FIG> depicts another placement technique for implanting a vaso-occlusive device called "recrossing. " In this technique, the delivery catheter extends through an opening in the stent. The stent prevents the coils from herniating out of the aneurysm sac. However, due to inherent unpredictability of positioning the delivery catheter through an opening of the stent, there is a risk that manipulation of the delivery catheter to direct and position the delivery catheter can cause the catheter tip to push into the dome thereby rupturing the aneurysm.

To address these herniation and implantation issues, vaso-occlusive coils have been developed which provide more neck coverage and shape stability to effectively "frame" an aneurysm. However, the three-dimensional shapes of current vaso-occlusive devices are either not conducive to framing or are prone to herniation during deployment into an aneurysm. Small aneurysms are best treated with as few coils as possible and current vaso-occlusive devices are not able to balance shape stability and softness as a standalone unit. Indeed, the shapes and configuration of current vaso-occlusive devices result in a directly proportional relationship between shape stability and softness. In other words, the softer the device (i.e., the less resistant to deformation from an external force), the less stable the device, and vice versa (i.e., the less soft the device, the more stable the shape of the vaso-occlusive device). Hence, a softer coil is less likely to rupture an aneurysm but is not able to retain its shape such that it is more prone to herniation out of the aneurysm during deployment and/or retention. Conversely, a stiffer coil is better able to retain its shape and frame the aneurysm, but imparts higher stresses on the aneurysm wall, creating high risk of rupturing the aneurysm, especially small aneurysms with a high rupture risk. In addition, particularly with outward complex shapes employed by current designs, the initial distal loops (e.g., first and second loops) have a higher likelihood of herniating out of the aneurysm due to subsequent loops pushing them out during deployment.

Accordingly, there is a need for vaso-occlusive devices which can alleviate the issues of herniation during placement and retention and provide effective framing of the aneurysm, and at the same time have a sufficiently soft and pliable structure that will not rupture the aneurysm, especially small, wide-necked aneurysms.

<CIT> discloses an implant for treatment of a vascular space that can form open loops and closed loops in separate cycles to provide balanced stiffness and flexibility. The implant comprises a strand forming, in a relaxed state, (i) first consecutive loops in a first cycle along a first length of the strand and (ii) second consecutive loops in a second cycle along a second length of the strand. Each of the first loops is an open loop that extends partially about a corresponding first axis, and each of the second loops is a closed loop that extends completely about a corresponding second axis that extends through a space within a radially adjacent one of the first loops. <CIT>, a document falling under Article <NUM>(<NUM>) EPC, discloses a vaso-occlusive device according to the preamble of claim <NUM>.

The presently claimed invention is defined by a vaso-occlusive device according to claim <NUM>. Further developments of the herein claimed invention are described in the dependent claims.

In accordance with one aspect of the presently disclosed medical devices and intravascular medical procedures, a vaso-occlusive device comprises an elongate vaso-occlusive device (e.g., from <NUM> to <NUM> in length) configured for implantation in an aneurysm sac. The vaso-occlusive devices disclosed herein are not limited to being configured and used for treating small, wide-necked aneurysms, but they are particularly well-suited for such configuration and use. The vaso-occlusive device typically has a delivery configuration (having a primary shape) when restrained within a delivery catheter and a deployed configuration (having a secondary shape different from the primary shape) when released from the delivery catheter into the aneurysmal sac.

The vaso-occlusive device includes wire having a primary configuration in a constrained condition. For instance, the primary configuration may be a shape of the wire when it is constrained within a delivery catheter, such as a helical coil shape, linear shape, or the like. The wire is also configured to form into a secondary configuration in a relaxed, unconstrained condition, such as when the wire is released from a delivery catheter with no external forces exerting on the wire.

The secondary configuration of the wire provides a balanced solution between shape stability and softness such that the vaso-occlusive device has a stable shape which prevents herniation during deployment and retention and provides effective framing of the aneurysm, while also having sufficient softness/pliability to avoid rupturing the aneurysm. The pyramidal shape has an inherent ability to effectively dissipate forces applied to its apexes, thereby reducing the risk of imparting excessive forces on the walls of the aneurysm which could rupture the aneurysm. Accordingly, the secondary configuration includes a pyramidal portion comprising a plurality of distal coils wound from the wire. Each distal coil includes a winding forming a closed loop of greater than <NUM>° wherein the winding has a perimeter which tapers outwardly from an interior of the pyramidal portion For example, for a helical coil shaped winding, the diameter of the coil tapers outwardly such that the interior part of the loops of the coil has a smaller diameter than outer part of the loops of the coil. Each distal coil also includes a transition segment of the wire between and connecting each distal coil to one or more adjacent distal coils.

The plurality of distal coils is arranged in a pyramidal shape such that each coil is parallel to, and lies in, a different lateral face of the pyramidal shape. For clarity, there is not a distal coil lying in the base of the pyramidal shape. For example, the pyramidal shape may be a tetrahedron having a base with <NUM> sides connected to an apex with each base side and the apex forming a triangle wherein each triangle defines one of the <NUM> lateral faces. The body portion described below may form the base portion of the pyramidal shape.

The secondary configuration also has a body portion proximal of the pyramidal portion. The body portion comprises a coil formed from the wire and extending proximally from the pyramidal portion. For example, the body portion may extend proximally from the position of the base of the pyramidal shape.

In another aspect, the pyramidal shape is a polyhedral shape formed of a polygonal base having n number of sides and n number of lateral faces connecting to an apex, such as a tetrahedral shape (triangular base and <NUM> lateral faces, also referred to as a triangular pyramid), pentahedral shape (quadrilateral base and <NUM> lateral faces, also referred to as a square or rectangular pyramid), hexahedral shape (pentagonal base and <NUM> lateral faces, also referred to as a pentagonal pyramid), etc..

In still another aspect, each of the distal coils comprises at least <NUM>-<NUM>/<NUM> loops or turns (winding of <NUM>°), or from <NUM>-<NUM>/<NUM> loops to <NUM>-<NUM>/<NUM> loops (winding of °). In still another feature, the distal coils are overlapping in the transition from one distal coil to an adjacent distal coil. In other words, the transition segment overlaps the coil as it extends from one distal coil to a subsequent, adjacent coil.

In another aspect, the primary configuration comprises an elongate helical coil. The helical coil has an outside diameter (OD) configured to fit within the lumen of a suitable delivery catheter for deploying the catheter. Typically, the elongate helical coil has zero pitch between each loop of the coil which provides the most compact coil. Alternatively, the elongate helical coil may have a non-zero pitch, or even a varying pitch.

In another aspect of the vaso-occlusive device, the wire may be formed from a shape memory material, and the secondary configuration is set by winding the wire on a mandrel and heat treating the wire wound on the mandrel.

In another aspect, each of the distal coils has a coil diameter (the diameter of the inner most loop of each distal coil) between <NUM> to <NUM> percent of a diameter of an aneurysm the device is designed to treat, or alternatively, a coil diameter (the diameter of the inner most loop of each distal coil) between <NUM> to <NUM> percent of a diameter of an aneurysm the device is designed to treat.

In another aspect of the vaso-occlusive device, the primary shape has a longitudinal length of from <NUM> to <NUM>.

Methods of making any of the vaso-occlusive devices described herein, and mandrels used to make the vaso-occlusive devices, are also disclosed. In one method of making a vaso-occlusive device using a mandrel, a mandrel for forming the vaso-occlusive device is provided. The mandrel comprises a central, spherical element. A plurality of distal coil posts extend from the central, spherical element. The distal coil posts are spaced angularly around the spherical element. Each distal coil post has a cross-sectional diameter which tapers outwardly as the distal coil post extends away from the spherical element. Each distal coil post also has a longitudinal axis which is oriented such that respective planes perpendicular to each respective longitudinal axis have an intersection which forms a pyramidal shape having an apex distal to the distal coil posts.

The mandrel also has a body post extending from the spherical element. Typically, the body post extends proximally from the spherical element.

A wire having a primary configuration is then wound around the mandrel. The wire may be formed of a shape memory material. The primary configuration may be a configuration of the wire in a constrained condition, such as within a sheath or delivery catheter, and can have any suitable shape, such as a helical coil.

The wire is wound around a first distal coil post of the plurality of distal coil posts in a first direction and winding inward towards the intersection of the first distal coil post and the spherical element and forming at least <NUM>°, or at least <NUM>-<NUM>/<NUM> first loops (<NUM>°) around the first distal coil post. As used herein, a winding "direction" is relative to viewing inwardly along the winding axis toward the position of the attachment of a winding post to the central, spherical element or other central structure. After winding the wire around the first distal coil post, the wire is traversed along the spherical element in a first transition segment to a next distal coil post immediately adjacent to the first distal coil post of the plurality of posts. The wire is then wound around the next distal coil post in a second direction opposite to the first direction starting at the intersection of the next distal coil post and the spherical element forming at least <NUM>-<NUM>/<NUM> next loops around the next distal coil post, and then traversing along the spherical element in a next transition segment to a subsequent distal coil post immediately adjacent to the preceding distal coil post. The process of winding the wire around each of the distal coil posts in alternating winding directions from the preceding distal coil post and transitioning to the subsequent distal coil post is repeated for each distal coil post. After winding the wire around the last of the distal coil posts, the wire is transitioned along the spherical element to the body post. The wire is then wound around the body post for at least one loop.

In another aspect of the method of making a vaso-occlusive device, the wire as wound around the mandrel is heat treated to set a secondary configuration of the vaso-occlusive device. In still another aspect, the secondary configuration is a relaxed, unconstrained configuration of the wire.

In yet another aspect of the method of making a vaso-occlusive device, the secondary configuration comprises a pyramidal portion and a body portion proximal of the pyramidal portion. The pyramidal portion comprises a plurality of distal coils wound from the wire on respective distal coil posts. Each distal coil comprises a winding forming a closed loop of greater than <NUM>°, or at least <NUM>-<NUM>/<NUM> loops, wherein the winding has a perimeter which tapers outwardly from an interior of the pyramidal portion. There is also a transition segment of the wire between each distal coil and connecting each distal coil. The plurality of distal coils are arranged in a pyramidal shape such that each coil lies in a different lateral face of the pyramidal shape. The body portion is proximal of the pyramidal portion, and comprises a coil formed from the wire wound on the body post, and extends proximally from the pyramidal portion.

In another aspect of the method, the pyramidal shape is a polyhedral shape formed of a polygonal base having n number of sides and n number of lateral faces connecting to an apex, such as a tetrahedral shape (triangular base and <NUM> lateral faces, also referred to as a triangular pyramid), pentahedral shape (square/quadrilateral base and <NUM> lateral faces, also referred to as a square pyramid), hexahedral (pentagonal base and <NUM> lateral faces, also referred to as a pentagonal pyramid), etc..

In still another aspect, each of the distal coils comprises at least <NUM>-<NUM>/<NUM> loops or turns, or from <NUM>-<NUM>/<NUM> loops to <NUM> loops. In another aspect, each transition segment crosses over at least part of the loops from which the transition segment is transitioning such that the distal coils are overlapping in the transition from one distal coil to an adjacent distal coil. In other words, the transition segment overlaps the coil as it extends from one distal coil to a subsequent, adjacent coil.

In still another aspect of the method, each post may have a cross-sectional diameter which tapers outwardly as the post extends away from the spherical element at an angle between about <NUM> to <NUM> degrees, or between about <NUM> to <NUM> degrees.

In additional aspects of the device disclosed herein, the vaso-occlusive devices disclosed herein may be a part of a vaso-occlusive system comprising a vaso-occlusive assembly and a delivery assembly. For example, a vaso-occlusive assembly may comprise any of the vaso-occlusive devices described herein, and a pusher member detachably coupled to a proximal end of the vaso-occlusive device. The pusher member is configured to allow a clinician to advance the vaso-occlusive device along a delivery catheter through a patient's vasculature to a target site, such as an aneurysm being treated with the vaso-occlusive device, and to push the vaso-occlusive device out of the distal end of the delivery catheter to deploy the vaso-occlusive device.

In still another aspect, the vaso-occlusive assembly may also include a detachment device detachably coupling the pusher member to the vaso-occlusive device. For example, the detachment device may comprise an electrolytic detachment, mechanical connector, heat activated detachment, dissolving detachment, etc. The delivery assembly may include a delivery catheter into which the vaso-occlusive device may be installed in its compact, delivery configuration. The delivery assembly may also include a guidewire for guiding the delivery catheter to a target implantation site within a patient's vasculature, such as an aneurysm. The guidewire is then be removed, and the vaso-occlusive device is advanced through the delivery catheter to the target implantation site.

In still another aspect of the present disclosure, the devices disclosed herein are not limited to being vaso-occlusive devices, but may be any medical device comprising the same or similar structure of the vaso-occlusive devices disclosed herein. For example, the medical device may be any suitable thrombectomy device, stent retriever, embolic filter, stent delivery system, other implantation device, guidewire, intravascular device, or other medical device.

Other and further aspects and features of embodiments of the disclosed inventions will become apparent from the ensuing detailed description in view of the accompanying figures.

The drawings illustrate the design and utility of various aspects of the devices and methods disclosed herein, in which similar elements are referred to by common reference numerals. It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the various aspects of the disclosed technology. They are not intended as an exhaustive description of the technology or as a limitation on the scope of the technology, which is defined only by the appended claims and their equivalents. In addition, an illustrated example of the disclosed technology need not have all the aspects or advantages shown or described herein. An aspect or an advantage described in conjunction with a particular example of the disclosed technology is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated. In order to better appreciate how the above-recited and other advantages and objects of the present technology are obtained, a more particular description of the present technology briefly described above will be rendered by reference to specific examples thereof, which are illustrated in the accompanying drawings. With the understanding that these drawings and corresponding description depict only illustrative examples of the disclosed technology and are not therefore to be considered limiting of its scope, the technology will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:.

Referring to <FIG>, an example of a vaso-occlusive device <NUM>, as disclosed herein, is illustrated. <FIG> depicts the vaso-occlusive device <NUM> in its secondary configuration in a relaxed, unconstrained condition. In other words, <FIG> shows the vaso-occlusive device <NUM> when there are no external forces exerting on the vaso-occlusive device <NUM>. The secondary configuration of the vaso-occlusive device <NUM> has a distal pyramidal portion <NUM> and a proximal body portion <NUM>, such that the distal pyramidal portion <NUM> is distal to the proximal body portion <NUM>. The terms "distal" and "proximal" as used herein are relative to the vaso-occlusive device <NUM> as it is intended to be deployed, wherein the term "distal" refers to being situated toward the end of the device <NUM> which is inserted first, and "proximal" refers to being situated toward the end of the device <NUM> which is inserted last.

The vaso-occlusive <NUM> comprises a wire <NUM> having a primary configuration in a constrained configuration. For instance, the constrained configuration may be an elongate, helical coil when the wire <NUM> is constrained within a delivery catheter (see <FIG>). Typically, the primary shape has a longitudinal length between <NUM> to <NUM>. The wire <NUM> is made from any suitable material, but typically comprises a radiopaque, shape memory material, such as the platinum group metals, including platinum, rhodium, palladium, and rhenium, as well as tungsten, gold, silver, tantalum, and alloys of these metals.

The pyramidal portion <NUM> in the secondary configuration of the vaso-occlusive device <NUM> is formed by a distal portion of the vaso-occlusive device <NUM> in its primary configuration (see <FIG>). The pyramidal portion <NUM> includes a plurality of distal coils <NUM> wound from the wire <NUM>. In the illustrated example of <FIG>, the pyramidal portion <NUM> includes three distal coils 108a, 108b, and 108c, arranged to form a pyramidal shape having three lateral faces, also referred to as a triangular pyramid as the base (the distal coils <NUM> do not include a distal coil at the base of the pyramidal shape) is a triangle, wherein a respective coil <NUM> lies in each lateral face of the triangular pyramid. The respective planes in which each distal coil <NUM> lies are non-parallel and intersect with each other. As depicted in <FIG>, a simplification of the intersecting planes of the distal coils <NUM> forms a tetrahedral, more specifically, a triangular pyramid. The vaso-occlusive device <NUM> of <FIG> is an example, and is not limited to distal coils <NUM> forming a triangular pyramid shape, but may be other suitable pyramidal shapes, such as n number of distal coils <NUM> forming a pyramid having a polygonal base having n number of sides and n number of lateral faces connecting to an apex. For instance, the vaso-occlusive device <NUM> may have distal coils <NUM> in each lateral face of a pyramidal shape which may be a square pyramid having a square base and <NUM> lateral faces, a quadrilateral pyramid having a quadrilateral base and <NUM> lateral faces, a pentagonal pyramid having a pentagonal base and <NUM> lateral faces, etc. As depicted in <FIG>, the pyramidal portion <NUM> may have <NUM> distal coils <NUM> in each lateral face arranged to form a square pyramid having a square base and <NUM> lateral faces.

Turning back to <FIG>, each distal coil <NUM> includes a winding forming a closed loop of greater than <NUM>°, i.e., at least a complete, closed loop. In the illustrated vaso-occlusive device <NUM>, each distal coil <NUM> includes a winding of <NUM>-<NUM>/<NUM> loops (also referred to as "turns"), which is equivalent to a winding of <NUM>°. Alternatively, each distal coil <NUM> may have at least <NUM>-<NUM>/<NUM> turns, or between <NUM>-<NUM>/<NUM> turns (<NUM>°) and <NUM> turns (<NUM>°).

The winding of each of the distal coils <NUM> also has a width which tapers outwardly from a reference point of the interior of the pyramidal portion. In the case of a helical coil as depicted in the example of <FIG>, the width of each distal coil <NUM> is the diameter of the coil. If the distal coils <NUM> are wound in a different shape, such as a square, pentagon, or other polygonal or curved shape, the width may be an average width, such an average of the maximum and minimum width drawn through the geometric center of the shape. Turning the example of <FIG>, the diameter of each distal coil <NUM> tapers such that the diameter of the outer part of the coil <NUM> is larger than the diameter of the inner part of the coil <NUM>. This may be better explained with reference to a cross-section of a cylindrical post upon which the distal coil <NUM> are wound, as shown in <FIG>. The post has a diameter which tapers outwardly from the inner part of the post to the outer part of the post, as depicted in <FIG>. The angle <NUM> of the post taper defines the angle of the taper of the distal coil <NUM> in the secondary configuration of the vaso-occlusive device <NUM>. Due to the outwardly tapering diameter, the loops or turns of each of the distal coils <NUM> is inward facing. In other words, the surface of the loops faces inward toward the geometric interior of the pyramidal shape of the pyramidal portion <NUM>.

Each of the distal coils <NUM> has a diameter (defined as the diameter of the inner most loop of each distal coil <NUM>) between <NUM> to <NUM> percent of a diameter of an aneurysm the vaso-occlusive device <NUM> is designed to treat. Alternatively, the diameter of each distal coil <NUM> may be between <NUM> to <NUM> percent of a diameter of an aneurysm the vaso-occlusive device <NUM> is designed to treat.

In an alternative design of the vaso-occlusive device <NUM>, the distal coils <NUM> may have differing diameters and/or differing numbers of turns of the wire <NUM>, as illustrated in <FIG>. As shown in <FIG>, the first distal coil 108a has a larger diameter and more turns of the wire <NUM> (<NUM> turns, i.e., <NUM>°) than the second distal coil 108b which has <NUM>-<NUM>/<NUM> turns (<NUM>°). The third distal coil 108c also has a larger diameter than the second distal coil 108b (same diameter as the first distal coil 108a and <NUM>-<NUM>/<NUM> turns (<NUM>°).

The pyramidal portion <NUM> also includes a respective transition segment <NUM> of the wire <NUM> which is between and connecting each adjacent distal coil <NUM> to each other. Each transition segment <NUM> extends from the ending of one distal coil <NUM> to the beginning of the subsequent distal coil <NUM>. Hence, the transition segment 110a extends from the ending of the distal coil 108a to the beginning of the distal coil 108b, and the transition segment 110b extends from the ending of the distal coil <NUM> to the beginning of the distal coil 108c. There is also a transition segment <NUM> from the ending of the last distal coil 108c winding to the beginning of the body portion <NUM>.

The body portion <NUM> comprises a winding of the wire <NUM> which extends proximally from the pyramidal shape <NUM>. The body portion <NUM> may extend from the imaginary base of the pyramidal shape of the pyramidal portion <NUM>. In the illustrated example of <FIG>, the body portion <NUM> is a helical coil extending proximally from the pyramidal portion <NUM>. The body portion <NUM> may have a constant diameter, or alternatively, the body portion <NUM> may have a diameter which tapers outwardly or inwardly as it extends from the proximally from the pyramidal portion <NUM>. The body portion <NUM> comprises at least one full loop of the wire <NUM>. The body portion <NUM> does not have a maximum degree of winding and may include any suitable number of turns, such as between <NUM> and <NUM> turns. The body portion <NUM> depicted in <FIG> has about <NUM> full turns of the wire <NUM>. The body portion <NUM> depicted in <FIG> has about <NUM> full turns of the wire <NUM>.

Turning to <FIG>, an exemplary mandrel <NUM> for making the vaso-occlusive device <NUM> using a method <NUM> (described below) is illustrated. The mandrel <NUM> is used to wind the wire <NUM> around to form the secondary configuration of the vaso-occlusive device <NUM>. The mandrel <NUM> is configured to form a vaso-occlusive device <NUM> comprising a pyramidal portion <NUM> having a triangular pyramid shape.

The mandrel <NUM> has a central, spherical element <NUM>. A plurality of distal coil posts <NUM> extend outwardly from the central spherical element <NUM>. The distal coil posts <NUM> are configured to form the distal coils <NUM> of the vaso-occlusive device <NUM>. The distal coil posts <NUM> are spaced angularly around the spherical element <NUM>. In the depicted mandrel <NUM>, the distal coil posts <NUM> are evenly spaced such that a respective longitudinal axis of each distal coil is evenly, angularly spaced around the spherical element <NUM>. Accordingly, in the case of three distal coil posts <NUM>, the distal coil posts <NUM> are spaced apart by <NUM>°.

Each distal coil post <NUM> has a cross-sectional diameter which tapers outwardly as the distal coil post <NUM> extends away from the spherical element <NUM>, as shown in <FIG> which shows a side view of one of the distal coil posts <NUM>. The angle <NUM> of the taper of the distal coil posts <NUM> is the same as the taper of the distal coils <NUM>, described herein. The longitudinal axis of each distal coil post <NUM> is also canted distally such that respective planes perpendicular to each respective longitudinal axis are non-parallel and non-perpendicular and the planes have an intersection which forms a pyramidal shape having an apex distal to the distal coil posts <NUM>.

The mandrel <NUM> also has a body post <NUM> extending from the spherical element <NUM>. The body post <NUM> is configured to form the body portion <NUM> of the vaso-occlusive device <NUM>. In the illustrated example of <FIG>, the body post <NUM> extends proximally from the spherical element <NUM> and perpendicular to the base of the pyramidal shape. The body post <NUM> may be a cylinder having a constant diameter, or alternatively, the body post <NUM> may taper outwardly or inwardly as it extends from the spherical element <NUM>.

With the assistance of the present description, one of ordinary skill in the art would appreciate how to modify the mandrel <NUM> to be configured to make a vaso-occlusive device <NUM> comprising a pyramidal portion <NUM> having the other pyramid shapes disclosed herein. For instance, <FIG> shows a mandrel <NUM> which is configured to make a vaso-occlusive device <NUM> comprising a pyramidal portion <NUM> having a square pyramid shape. The mandrel <NUM> is same or substantially similar to the mandrel <NUM>, except that the mandrel <NUM> has four distal coil posts <NUM> evenly, angularly spaced around the central, spherical member <NUM>.

Turning to the illustrations in <FIG> and the flow chart of <FIG>, an exemplary method <NUM> of making a vaso-occlusive device <NUM> using the mandrel <NUM> will now be described. A wire <NUM> having a primary configuration is wound around the mandrel <NUM>. As described herein, the wire <NUM> may be formed of a shape memory material, and the primary configuration may be a configuration of the wire <NUM> in a constrained condition, such as within a sheath or delivery catheter. The primary configuration may have any suitable shape, such as a helical coil.

At step <NUM>, the wire <NUM> is first wound around the first distal coil post 108a in a first direction starting on the first distal coil post 108a post and towards the intersection of the first distal coil post 204a, and the spherical element <NUM>. Subsequent windings start at the intersection of the post <NUM> and spherical element <NUM> and wind away from the spherical element <NUM>. As used herein, a winding "direction" is relative to viewing inwardly along the winding axis toward the position of the attachment of a winding post to the central, spherical element or other central structure. Thus, the "first direction" as shown in the example of <FIG> is a clockwise direction. The wire <NUM> is wound around the first distal coil post 204a to form the desired degree of winding for the first distal coil 108a, as described herein.

After winding the wire <NUM> around the first distal coil post 204a, at step <NUM>, the wire <NUM> is traversed along the spherical element <NUM> forming the first transition segment 110a to the second distal coil post 108b immediately adjacent to the first distal coil post 108a. At step <NUM>, the wire <NUM> is wound around the second distal coil post 204b in a second direction opposite to the first direction (counterclockwise as shown in the example of <FIG>) starting at the intersection of the second distal coil post 204b and the spherical element <NUM>. The wire <NUM> is wound around the second distal coil post 204b to form the desired degree of winding for the second distal coil 108a, as described herein.

After winding the wire <NUM> around the second distal coil post 204b, at step <NUM>, the wire <NUM> is traversed along the spherical element <NUM> forming the second transition segment 110a to the third distal coil post 204c immediately adjacent to the second distal coil post 204b. At step <NUM>, the wire <NUM> is wound around the third distal coil post 204c in a third direction opposite to the second direction (clockwise as shown in the example of <FIG>) starting at the intersection of the third distal coil post 204c and the spherical element <NUM>. The wire <NUM> is wound around the third distal coil post 204c to form the desired degree of winding for the third distal coil 108c, as described herein.

Looking at a post <NUM> that is being wound axially along the axis of rotation, each of the three other posts <NUM> can be described at <NUM>/<NUM> rotations as the coil is being wound. Accordingly, a winding of <NUM>-<NUM>/<NUM> loops or turns (i.e., <NUM>°) means that as the wire <NUM> is wound around the post <NUM>, each of the other posts <NUM>, <NUM> that are passed represents and winding of <NUM>/<NUM> of a loop or turn. Hence, a winding of <NUM>-<NUM>/<NUM> loops passes the three other posts <NUM>, <NUM> once, and then re-passes <NUM> of the <NUM> other posts <NUM>, <NUM> for a total of <NUM>-<NUM>/<NUM> loops. A winding of about <NUM>-<NUM>/<NUM> (<NUM>°) passes each of the other posts <NUM>, <NUM> twice and then passes the next <NUM> posts a third time. The winding of a full loop (<NUM>°), or multiple full loops (<NUM>° x a whole number) plus another <NUM>/<NUM> of a loop, positions the end of a coil <NUM> to wind in the opposite direction on the next adjacent post <NUM>. One of ordinary skill in the art will immediately understand how to determine the correct amount of loops for a mandrel having more than <NUM> posts <NUM>, such as <NUM> posts <NUM>, <NUM> posts <NUM>, etc..

In the case of a mandrel <NUM> having more than <NUM> distal coil posts <NUM>, at step <NUM>, the wire is <NUM> traversed along the spherical element <NUM> in a next transition segment <NUM> to a next distal coil post <NUM> immediately adjacent to the preceding distal coil post <NUM>. At step <NUM>, the wire is wound around the next distal coil post <NUM> to form the next distal coil <NUM>, and steps <NUM>-<NUM> are repeated for each additional distal coil post <NUM>. After winding the wire around the last of the distal coil posts <NUM>, at step <NUM>, the wire <NUM> is transitioned along the spherical element <NUM> to the body post <NUM>. At step <NUM>, the wire <NUM> is wound around the body post <NUM> to form the desired degree of winding for the body portion <NUM>, as described herein.

At step <NUM>, the wire <NUM> is heat treated to set the secondary configuration of the vaso-occlusive device <NUM> as wound on the mandrel <NUM>. The wire <NUM> may then be removed from the mandrel <NUM>, and the wire <NUM> will take on the secondary configuration having the secondary shape as wound on the mandrel in its relaxed, unconstrained condition.

Accordingly, disclosed herein are a vaso-occlusive device <NUM>, and method <NUM> for making it, which alleviates the issues of herniation during placement and retention and provides effective framing of the aneurysm, while at the same time have a sufficiently soft and pliable structure that will not rupture the aneurysm, especially small and/or wide-necked aneurysms. The pyramidal shape of the distal coils <NUM> of vaso-occlusive device <NUM> has in inherent ability to effectively dissipates forces applied to its apexes, thereby reducing the risk of imparting excessive forces on the walls of the aneurysm which could rupture the aneurysm, including small and/or wide-necked aneurysms. Furthermore, the distal coils are tapered to be inwardly facing and comprise full, closed loops and crossing, overlapping segments which fold more tightly than open loops when deployed in an aneurysm thereby reducing the risk of herniation during placement and retention. At the same time, shape stability is not compromised because of the inherent ability of the pyramidal shape to dissipate forces applied at the apexes. Furthermore, as illustrated in <FIG>, the pyramidal shaped vaso-occlusive device <NUM> is more compact than a cube shaped vaso-occlusive device having <NUM> coils forming the <NUM> sides of a cube. In other words, the volume of the pyramidal shaped vaso-occlusive device <NUM> has a smaller volume than a cube. In addition, the distal coils <NUM> of the vaso-occlusive device <NUM> have a smaller diameter than the coils of a cube shaped vaso-occlusive device having the same or substantially same overall height as the vaso-occlusive device <NUM>. This is because the diameter of each of the distal coils <NUM> is smaller than the overall height of the vaso-occlusive device <NUM> (e.g., <NUM> diameter of the distal coils vs. a <NUM> overall height of the vaso-occlusive device <NUM>. Whereas, the diameter of the coils of a cube shaped vaso-occlusive device extend the full height of the entire vaso-occlusive device (the height being the length of any one of the sides of the cube shaped vaso-occlusive device.

Turning to <FIG>, the vaso-occlusive device <NUM> may also be a component of a vaso-occlusive system <NUM> which can be used to deploy the vaso-occlusive device <NUM> into a body cavity, such as an aneurysm <NUM> (see <FIG>). The vaso-occlusive system <NUM> comprises a delivery assembly <NUM> and a vaso-occlusive assembly <NUM>. As shown in <FIG> and <FIG>, the delivery assembly <NUM> may include a delivery catheter <NUM> and an optional guidewire <NUM>. The vaso-occlusive assembly <NUM> comprises a vaso-occlusive device <NUM> and a pusher member <NUM> detachably coupled to the vaso-occlusive device <NUM> via a detachment device or junction <NUM>. <FIG> shows the vaso-occlusive assembly <NUM> after it has been slidably disposed within the delivery catheter <NUM> such that the vaso-occlusive device <NUM> is in its compact, delivery configuration.

The delivery catheter <NUM> is typically an elongated, flexible tube, and can be, for example, a microcatheter or the like. The delivery catheter <NUM> comprises an elongate sheath body <NUM> having a proximal portion <NUM>, a distal portion <NUM> and a lumen <NUM> extending from the proximal portion <NUM> to the distal portion <NUM>. The proximal portion <NUM> of the delivery catheter <NUM> typically remains outside of the patient and accessible to the clinician when the vaso-occlusive system <NUM> is used, while the distal portion <NUM> is sized and dimensioned to reach remote locations of a patient's vasculature and is configured to deliver the vaso-occlusive device <NUM> to a body cavity such as an aneurysm. The delivery catheter <NUM> may also have one or more ports <NUM> in fluid communication with the lumen <NUM> for introducing into, or removing fluids from, the sheath body <NUM>. The sheath body <NUM> may be composed of suitable polymeric materials, metals and/or alloys, such as polyethylene, stainless steel or other suitable biocompatible materials or combinations thereof. In some instances, the proximal portion <NUM> may include a reinforcement layer, such as a braided layer or coiled layer to enhance the pushability of the sheath body <NUM>. The sheath body <NUM> may include a transition region between the proximal portion <NUM> and the distal portion <NUM>.

The vaso-occlusive device <NUM> may be any of the vaso-occlusive device <NUM> disclosed herein, having any one or more of the features and aspects described herein.

The vaso-occlusive assembly <NUM> also comprises a pusher member <NUM>. The pusher member <NUM> is configured to be slidably received within the lumen <NUM> of the delivery catheter <NUM>. The pusher member <NUM> has a proximal portion <NUM>, which typically extends proximal of the proximal portion <NUM> of the delivery catheter <NUM>, and a distal portion <NUM> which is detachably coupled to the proximal end of the vaso-occlusive device <NUM> via the detachment device <NUM>. The pusher member <NUM> may be a coil, wire, tendon, conventional guidewire, torqueable cable tube, hypotube, or the like, having a sufficient columnar strength to permit pushing of the vaso-occlusive device <NUM> out through distal end <NUM> of the delivery catheter <NUM> and into the aneurysmal sac <NUM> (see <FIG> and <FIG>).

The detachment device <NUM> provides a detachable connection between the pusher member <NUM> and the vaso-occlusive device <NUM>. The detachment device <NUM> may comprise an electrolytically detachment, mechanical connector, heat activated detachment, dissolving detachment, or other mechanical, thermal and hydraulic mechanism. For instance, the detachment device <NUM> may be an electrolytically degradable segment for electrolytically decoupling the vaso-occlusive device <NUM> from the pusher member <NUM>.

As shown in <FIG> and <FIG>, the optional guidewire <NUM> of the delivery assembly <NUM> has a proximal end <NUM> and a distal end <NUM>. As shown in <FIG>, after the guidewire <NUM> is positioned within the patient's vasculature <NUM> with the distal end <NUM> located at the target insertion site, the delivery catheter <NUM> is advanced over the guidewire <NUM> with the guidewire <NUM> disposed within the lumen <NUM> of the delivery catheter <NUM>. In a "rapid-exchange" configuration of the delivery catheter <NUM> and guidewire <NUM>, the guidewire <NUM> extends through only a distal portion of the delivery catheter <NUM>, such as a rapid-exchange lumen. The guidewire <NUM> is typically used by first advancing the guidewire <NUM> through the patient's vasculature to the target insertion site (e.g., the neck <NUM> of an aneurysm to be filled by the vaso-occlusive device <NUM>, see <FIG>), and then advancing the delivery catheter <NUM> over the guidewire <NUM> to the target insertion site.

Turning to <FIG>, an exemplary method <NUM> of using the vaso-occlusive system <NUM> to deploy the vaso-occlusive device <NUM> into an anatomical cavity will now be described. The method <NUM> will be described with respect to deploying the vaso-occlusive device <NUM> into an aneurysmal sac <NUM>, as an example. However, the method <NUM> is not limited to deploying the vaso-occlusive device <NUM> into an aneurysmal sac <NUM>, but may be used to deploy the vaso-occlusive device <NUM>, or other medical device as disclosed herein, into any suitable anatomical cavity which is accessible via a patient's vasculature. Referring to the flow chart of <FIG> and <FIG>, at step <NUM>, the guidewire <NUM> is inserted into the patient's vasculature <NUM> and is advanced to the target insertion site, namely the aneurysmal sac <NUM>. As described herein, the use of the guidewire <NUM> is optional, and is not required in the method <NUM> of using the vaso-occlusive system <NUM> to deploy the vaso-occlusive device <NUM>.

At step <NUM>, the delivery catheter <NUM> of the delivery assembly <NUM> is advanced over the guidewire <NUM> until it is positioned with the open distal end <NUM> adjacent or within the aneurysmal neck <NUM> of the aneurysm <NUM>, as shown in <FIG>. At step <NUM>, the guidewire <NUM> is pulled out of the delivery catheter <NUM> leaving the delivery catheter <NUM> in position. At step <NUM>, the vaso-occlusive assembly <NUM> is inserted into the delivery catheter <NUM> of the delivery assembly <NUM> and advanced within the delivery catheter <NUM> to position the distal end of the vaso-occlusive device <NUM> adjacent the distal portion <NUM> of the delivery catheter <NUM>, as shown in <FIG>. At this position, the proximal portion <NUM> of the pusher member <NUM> remains proximal and outside of the proximal portion <NUM> of the delivery catheter <NUM>. Prior to inserting the vaso-occlusive device <NUM> into the delivery catheter <NUM>, the vaso-occlusive device <NUM> may be pre-installed in a sheath such that the vaso-occlusive device <NUM> is in its constrained, delivery configuration (primary configuration). The vaso-occlusive device <NUM> is then inserted into the delivery catheter <NUM> by placing a distal end of the sheath in abutment with the proximal end <NUM> of the delivery catheter <NUM> and extruding the vaso-occlusive device <NUM> from the sheath into the delivery catheter <NUM> such that the vaso-occlusive device <NUM> remains in its delivery configuration within the delivery catheter <NUM>.

Claim 1:
A vaso-occlusive device, comprising:
a wire (<NUM>) having a primary configuration in a constrained condition;
wherein the wire (<NUM>) forms a secondary configuration in a relaxed, unconstrained condition, the secondary configuration comprising:
a pyramidal portion (<NUM>) comprising a plurality of distal coils (<NUM>) wound from the wire (<NUM>), each distal coil (<NUM>) comprising a winding forming a closed loop of greater than <NUM>° wherein the winding has a perimeter which tapers outwardly from an interior of the pyramidal portion (<NUM>), and a transition segment (<NUM>) of the wire (<NUM>) between each distal coil (<NUM>) and connecting each distal coil (<NUM>) to an adjacent distal coil (<NUM>) and each of the distal coils (<NUM>) overlapping in a transition from one distal coil (<NUM>) to an adjacent distal coil (<NUM>),
the plurality of distal coils (<NUM>) arranged in a pyramidal shape such that each coil (<NUM>) lies in a different lateral face of the pyramidal shape; and
a body portion (<NUM>) proximal of the pyramidal portion (<NUM>), the body portion (<NUM>) comprising a coil formed from the wire (<NUM>) and extending proximally from the pyramidal portion
characterized in that:
the perimeter of each distal coil (<NUM>) tapers outwardly from an interior of the pyramidal portion (<NUM>) at an angle between <NUM> to <NUM> degrees; and
each of the distal coils (<NUM>) comprising from <NUM>-<NUM>/<NUM> turns to <NUM> turns.