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, which 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in a desired position for releasing one or more vaso-occlusive device(s) into the aneurysmal sac once the guidewire is withdrawn.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device is then released or "detached" from the distal end of the delivery assembly, and the delivery assembly is withdrawn back through the micro-catheter.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> shows a <FIG> depicts a portion of a vaso-occlusive coil herniating out of the aneurysm after introduction into the aneurysm.

Variations in the stiffness of the wire from which current vaso-occlusive devices are formed, and variations in the stiffness of the stretch resistant sutures often used in the current coil designs, also cause the oversizing of the leading (or distal) loop. The distal loop is the first loop of the vaso-occlusive device deployed into the aneurysm. The oversizing of the distal loop also causes a tendency for the distal tip (i.e., the leading end of the distal loop) to herniate out of the aneurysm during deployment. <FIG> shows one example of herniation during an initial deployment of a vaso-occlusive coil. As the vaso-occlusive coil is advanced out of the delivery catheter, the distal loop of the coil is unconstrained, and as the distal loop takes on its unconstrained configuration, the distal loop can bend around in the aneurysm such that the distal tip herniates out of the aneurysm and into the parent vessel. <FIG> shows another example in which the deployment of subsequent coils into the aneurysm causes significant displacement of the distal loop, causing rotation and tumbling of the distal loop which can also result in herniation due to this unpredictable movement. In order to compensate for these conditions, the clinician is forced to constantly manipulate the vaso-occlusive coil and /or delivery catheter, such as advancing, withdrawing and/or rotating the coil and catheter, as the coil is being deployed to prevent herniation.

Several placement techniques have also been developed to alleviate coil herniation during placement. One such placement technique, called a "remodeling or 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 remodeling 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 latter are 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 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 technique 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.

Patent Application Publication No. <CIT> discloses an implant device for implantation in a lung for treating lung disease such as emphysema. In one disclosed embodiment, an implant device <NUM> includes a coil formed of a wire having a primary configuration having a proximal end <NUM> and a distal end <NUM> and a secondary configuration in a relaxed, unconstrained condition. The secondary configuration includes a plurality of helical loops <NUM> including a distal most loop having a proximal end and a distal end and a perimeter length from the proximal end to the distal end. The implant device <NUM> also has a transition <NUM> connected to the distal end <NUM> of helical section <NUM>. Document <CIT> discloses a vaso-occlusive device according to the preamble of claim <NUM>. 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.

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. The object of the present invention is to satisfy these needs.

In accordance with the presently disclosed medical devices a vaso-occlusive device is described which has a design as defined by the attached claims.

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. The examples of vaso-occlusive devices are described in detail herein as vaso-occlusive devices for occluding aneurysms, with the understanding that the devices are not limited to being configured for deployment into an aneurysm, but may be sized and configured for occluding any suitable anatomical cavity. Moreover, the devices are not limited to being occlusive devices, but may be any suitable medical device, such as a thrombectomy device, stent retriever, embolic filter, stent delivery system, other implantation device, guidewire, intravascular device, or the like.

<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 primary portion <NUM>, a base portion <NUM>, and a distal anchoring loop <NUM>. The primary portion <NUM> is distal to the body portion <NUM>, and the distal anchoring loop <NUM> is distal to the primary 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 coil formed of 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 distal anchoring loop <NUM> in the secondary configuration of the vaso-occlusive device <NUM> is formed by a distal-most portion of the vaso-occlusive device <NUM> in its primary configuration (see <FIG>). The primary portion <NUM> in the secondary configuration of the vaso-occlusive device <NUM> is formed by a portion of the vaso-occlusive device <NUM> in its primary configuration just proximal of the distal anchoring loop (see <FIG>).

The primary portion <NUM> includes a plurality of primary loops <NUM> wound from the wire <NUM>. In the illustrated example of <FIG>, the primary portion <NUM> includes three primary loops 108a, 108b, and 108c. The first primary loop 108a (also referred to as the "distal primary loop") is the distal-most primary loop <NUM>, the second primary loop 108b is just proximal of the first primary loop 108a, and the third primary loop 108c is just proximal of the second primary loop 108b (i.e., it is the proximal-most primary loop <NUM>). The primary loops <NUM> are connected end to end, such that a proximal end of the first primary loop 108a is connected to the distal end of the second primary loop 108b, and the proximal end of the second primary loop 108b is connected to the distal end of the third primary loop 108c.

In the illustrated example of <FIG>, the primary portion <NUM> includes three primary loops 108a, 108b, and 108c, arranged to form a pyramidal shape having three lateral faces, also referred to as a triangular pyramid. The pyramidal shape in the example of <FIG> is referred to as a triangular pyramid because the base of the pyramidal shape (the primary loops <NUM> do not include a distal coil at the base of the pyramidal shape, however, the body portion <NUM> described below may form the base portion 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 the respective turns/loops of each primary loop <NUM> lie are non-parallel and intersect with each other. As depicted in <FIG> , a simplification of the intersecting planes of the primary loops <NUM> forms a tetrahedral, more specifically, a triangular pyramid. The vaso-occlusive device <NUM> of <FIG> is an example, and is not limited to primary loops <NUM> forming a triangular pyramid shape, but may be other suitable pyramidal shapes, such as n number of primary loops <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 primary loops <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 primary portion <NUM> may have <NUM> primary loops <NUM> in each lateral face arranged to form a square pyramid having a square base and <NUM> lateral faces.

Turning back to <FIG>, each primary loop <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 primary loop <NUM> includes a winding of <NUM>-<NUM>/<NUM> loops (also referred to as "turns"), which is equivalent to a winding of <NUM>°. Alternatively, each primary loop <NUM> may have at least <NUM>-<NUM>/<NUM> turns, or between <NUM>-<NUM>/<NUM> turns (<NUM>°) and <NUM>-<NUM>/<NUM> turns (<NUM>°).

The winding of each of the primary loops <NUM> may also have a width which tapers outwardly from a reference point of the interior of the primary portion <NUM>. In the case of a helical coil as depicted in the example of <FIG>, the width of each primary loop <NUM> is the diameter of the coil. If the primary loops <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 to the example of <FIG>, the diameter of each primary loop <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 primary loop <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 primary loop <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 primary loops <NUM> is inward facing. In other words, the surface of the loops faces inward toward the geometric interior of the pyramidal shape of the primary portion <NUM>.

Each of the primary loops <NUM> has a diameter (defined as the diameter of the inner most loop of each primary loop <NUM>) between <NUM> to <NUM> percent of a diameter of an aneurysm (or other anatomical cavity to be filled by the vaso-occlusive device <NUM>) the vaso-occlusive device <NUM> is designed to treat. Alternatively, the diameter of each primary loop <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 primary loops <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 primary loop 108a has a larger diameter and more turns of the wire <NUM> (<NUM> turns, i.e., <NUM>°) than the second primary loop 108b which has <NUM>-<NUM>/<NUM> turns (<NUM>°). The third primary loop 108c also has a larger diameter than the second primary loop 108b (same diameter as the first primary loop 108a and <NUM>-<NUM>/<NUM> turns (<NUM>°).

The distal primary loop 108a has a perimeter (i.e., length of the wire <NUM> forming the distal primary loop 108a) from its proximal end to its distal end. For a circular shaped distal primary loop 108a, the perimeter is a circumference or arc length equal to the 2πr(Θ/<NUM>), where "r" is the radius of the arc, and "Θ" is the angle of the arc. The individual turns of the distal primary loop 108a lie substantially in a respective one of a plurality of parallel planes, including a first plane, such that each loop lies in a substantially two-dimensional surface.

The primary portion <NUM> also includes a respective transition segment <NUM> of the wire <NUM> which is between and connecting each adjacent primary loop <NUM> to each other. Each transition segment <NUM> extends from the ending of one primary loop <NUM> to the beginning of the subsequent primary loop <NUM>. Hence, the transition segment 110a extends from the proximal end (ending) of the primary loop 108a to the distal end (beginning) of the primary loop 108b, and the transition segment 110b extends from the proximal end (ending) of the primary loop 108b to the distal end (beginning) of the primary loop 108c. There is also a transition segment <NUM> from the proximal end of the last primary loop 108c winding to the distal end of the body portion <NUM>, and a distal anchoring loop ("DAL") transition segment <NUM> from the proximal end of the distal anchoring loop <NUM> to the distal end of the first primary loop 108a.

The distal anchoring loop <NUM> is at the distal-most end of the vaso-occlusive device <NUM> such that it is the first element of the vaso-occlusive device <NUM> to be inserted into a body cavity (e.g., an aneurysm) during deployment of vaso-occlusive device. The distal anchoring loop <NUM> has a substantially triangular shape and is substantially smaller in size than the first (i.e., distal) primary loop 108a. The distal anchoring loop <NUM> has a distal tip <NUM>, which represents the leading tip of vaso-occlusive device <NUM>, i.e., the distal tip <NUM> is the distal-most end of the vaso-occlusive device <NUM>. The triangular shape of the distal anchoring loop <NUM> is more difficult to deform and/or displace upon deployment when it assumes its secondary configuration within an aneurysm than other shapes, such as circular and quadrilateral, as illustrated in <FIG>.

As depicted in <FIG>, the substantially triangular shape of the distal anchoring loop <NUM> is formed of a base "C" and two sides "E" and "A" connected to the base "C". Each of the sides "E" and "A" is connected to the base by rounded vertices, and the angle "Θ" between the base "C" and each of the sides "E" and "A" is from <NUM>° to <NUM>°. Alternatively, the angle "Θ" between the base "C" and each of the sides "E" and "A" may be from <NUM>° to <NUM>°.

The distal anchoring loop <NUM> has an overall length which is the length of the wire <NUM> forming the distal anchoring loop <NUM>. As shown in <FIG>, overall length of the distal anchoring loop <NUM> illustrated in <FIG> is sum of the length of the <NUM> sides of the substantially triangular shape (A + C + E), and the length(s) of the arcs forming the filleted vertices (B + D) of the substantially triangular shape. As depicted in <FIG>, the distal anchoring loop <NUM> may have an overall length "F" of <NUM>% to <NUM>% of the perimeter of the distal primary loop 108a, or the distal anchoring loop <NUM> may have an overall length of <NUM>% to <NUM>% of the perimeter of the distal primary loop 108a, or the distal anchoring loop <NUM> may have an overall length of less than <NUM>% of the perimeter of the distal primary loop 108a.

As shown in <FIG>, the distal anchoring loop <NUM> is positioned within a projection of the distal primary loop 108a. In other words, the distal anchoring loop <NUM> is positioned either within the perimeter of the distal primary loop 108a (e.g., co-planar), or it is positioned within a perpendicular projection of the perimeter of the distal primary loop 108a (e.g., the distal anchoring loop may be parallel to the first plane and out of the planes of distal primary loop 108a). The partial side view of <FIG> shows the distal anchoring loop <NUM> positioned out of, and parallel to, the planes of the distal primary loop 108a.

<FIG> illustrate a comparison of the vaso-occlusive device <NUM> having different locations for the starting point of the distal anchoring loop <NUM>. The starting point of the distal anchoring loop <NUM> is where the distal anchoring loop <NUM> connects to the distal primary loop 108a. The vaso-occlusive device <NUM> in <FIG> has a starting point <NUM> of the distal anchoring loop <NUM> at between about a <NUM>:<NUM> o'clock and an <NUM>:<NUM> o'clock position relative to a longitudinal axis <NUM> of the primary configuration of the wire <NUM> being at a <NUM>:<NUM> o'clock position. This results in a distal primary loop 108a which starts at about this same position. This is in contrast to the vaso-occlusive device 100a in <FIG> which has a starting point <NUM> of the distal anchoring loop <NUM> at about a <NUM>:<NUM> o'clock position relative to the longitudinal axis <NUM>. As a result of the different starting points of the distal anchoring loop <NUM>, the distal primary loop 108a in the device <NUM> in <FIG> is longer than the distal primary loop 108a in the device 100a of <FIG>. This longer distal primary loop 108a of the vaso-occlusive device in <FIG> provides better initial framing of the device <NUM> during deployment of the vaso-occlusive device <NUM> into an aneurysm than the shorter distal primary loop 108a of the vaso-occlusive device in <FIG>. It has been found through empirical testing, the starting point <NUM> of the distal anchoring loop <NUM> between about a <NUM>:<NUM> o'clock and an <NUM>:<NUM> o'clock position relative to a longitudinal axis <NUM> provides better initial framing of the aneurysm during deployment than starting points <NUM> at other positions which provide different lengths for the distal primary loop 108a, such as between <NUM> o'clock to <NUM> o'clock, <NUM>'clock to <NUM> o'clock, and <NUM> o'clock to <NUM> o'clock.

Referring to <FIG>, the body portion <NUM> comprises a winding of the wire <NUM> which extends proximally from the primary portion <NUM>. The body portion <NUM> may extend from the imaginary base of the pyramidal shape of the primary 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 primary 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>-<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 the primary portion <NUM> having a triangular pyramid shape, the distal anchoring loop <NUM> and base portion <NUM>.

The mandrel <NUM> has a central, spherical element <NUM> (also referred to as a "support member"). A plurality of primary loop posts <NUM> extend outwardly from the central spherical element <NUM>. Each primary loop post has a first end connected to the spherical element <NUM>, a second end extended away from the spherical element <NUM>. and a perimeter for winding the wire onto the respective primary loop post <NUM>. The primary loop posts <NUM> are configured to form the primary loops <NUM> of the vaso-occlusive device <NUM>. Accordingly, a primary loop post 204a forms the distal primary loop 108a, the primary loop post 204b forms the primary loop 108b and the primary loop post 204c forms the primary loop 108c, and so on depending on the number of primary loop post <NUM> and primary loops <NUM>. The primary loop posts <NUM> are spaced angularly around the spherical element <NUM>. In the depicted mandrel <NUM>, the primary loop posts <NUM> are evenly spaced such that a respective longitudinal axis of each primary loop is evenly, angularly spaced around the spherical element <NUM>. Accordingly, in the case of three primary loop posts <NUM>, the primary loop posts <NUM> are spaced apart by <NUM>°.

The perimeter of each primary loop post <NUM> has cross-sectional diameter which tapers outwardly as the primary loop post <NUM> extends away from the spherical element <NUM>, as shown in <FIG> which shows a side view of one of the primary loop posts <NUM>. The angle <NUM> of the taper of the primary loop posts <NUM> is the same as the taper of the primary loops <NUM>, described herein. The longitudinal axis of each primary loop 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 primary loop posts <NUM>.

The mandrel <NUM> also has a distal anchoring loop sub-mandrel <NUM> coupled to the second end of the distal primary loop post 204a. The distal anchoring loop sub-mandrel <NUM> may extend outward from the second end of the distal primary loop post 204a. The distal anchoring loop sub-mandrel <NUM> is configured to form the distal anchoring loop <NUM> in its substantially triangular shaped loop from the wire <NUM>. The distal anchoring loop sub-mandrel <NUM> is also oriented to set the starting point <NUM> of the distal anchoring loop <NUM> between about a <NUM>:<NUM> o'clock and an <NUM>:<NUM> o'clock position relative to a longitudinal axis <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 of the primary portion <NUM>. 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 primary 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 primary 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 primary loop 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 coil formed of 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 wound around the distal anchoring loop post <NUM> to form the distal anchoring loop <NUM>. At step <NUM>, the wire <NUM> is traversed to the distal end of the first primary loop 108a to form the DAL transition segment <NUM>. At step <NUM>, the wire <NUM> is wound around the first primary loop post 204a in a first direction and winding inward towards the intersection of the first primary loop 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 primary loop post 204a to form the desired degree of winding for the first primary loop 108a, as described herein.

After winding the wire <NUM> around the first primary loop post 204a, at step <NUM>, the wire <NUM> is traversed along the spherical element <NUM> forming the first transition segment 110a to the second primary loop post 204b immediately adjacent to the first primary loop post 108a. At step <NUM>, the wire <NUM> is wound around the second primary loop post 204b in a second direction opposite to the first direction (counterclockwise as shown in the example of FIGS. 16A-16B) starting at the intersection of the second primary loop post 204b and the spherical element <NUM>. The wire <NUM> is wound around the second primary loop post 204b to form the desired degree of winding for the second primary loop 108a, as described herein.

After winding the wire <NUM> around the second primary loop post 204b, at step <NUM>, the wire <NUM> is traversed along the spherical element <NUM> forming the second transition segment 110a to the third primary loop post 204c immediately adjacent to the second primary loop post 204b. At step <NUM>, the wire <NUM> is wound around the third primary loop post 204c in a third direction opposite to the second direction (clockwise as shown in the example of FIGS. 16A-16B) starting at the intersection of the third primary loop post 204c and the spherical element <NUM>. The wire <NUM> is wound around the third primary loop post 204c to form the desired degree of winding for the third primary loop 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> primary loop posts <NUM>, at step <NUM>, the wire is <NUM> traversed along the spherical element <NUM> in a next transition segment <NUM> to a next primary loop post <NUM> immediately adjacent to the preceding primary loop post <NUM>. At step <NUM>, the wire is wound around the next primary loop post <NUM> to form the next primary loop <NUM>, and steps <NUM>-<NUM> are repeated for each additional primary loop post <NUM>. After winding the wire <NUM> around the last of the primary loop 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> as wound on the mandrel <NUM> is heat treated to set the secondary configuration of the vaso-occlusive device <NUM> as wound on the mandrel <NUM>. At step <NUM>, the wire <NUM> is 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.

It is understood that the vaso-occlusive device <NUM> can also be formed by winding the wire <NUM> around the mandrel in the opposite direction. In other words, the wire <NUM> is first wound around the body post <NUM> to form the body portion <NUM>. Then the wire <NUM> is wound around each of the primary loop posts <NUM> for greater than <NUM>° to form each of the primary loops <NUM>, and the resulting plurality of primary loops <NUM> are arranged in a pyramidal shape such that each primary loop <NUM> lies in a different lateral face of the pyramidal shape. The wire <NUM> is then wound around the distal anchoring loop post <NUM> post to form the distal anchoring loop <NUM>. The wire <NUM> is also traversed to form each of the transition segments <NUM>, in the opposite order from the method <NUM> described above. Indeed, the order of the steps of the method <NUM> may be performed in any suitable order, and the method <NUM> is not limited to any particular order of the steps.

Accordingly, disclosed herein are a vaso-occlusive device <NUM>, and for the sake of illustration a 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 size, shape and location of the distal anchoring loop <NUM> effectively avoids herniation of the vaso-occlusive device <NUM> out of the aneurysm during deployment. <FIG> illustrate the initial deployment of the vaso-occlusive device <NUM> out of a delivery catheter <NUM> into an aneurysm <NUM>, showing how the distal anchoring loop <NUM> functions to avoid herniation during insertion. Upon initial deployment of the vaso-occlusive device <NUM>, the distal tip <NUM> of the distal anchoring loop <NUM> first enters the aneurysm <NUM>. As depicted in <FIG>, as the distal anchoring loop <NUM> is advanced out of the delivery catheter, it assumes its triangular shape in the secondary configuration of the vaso-occlusive device <NUM>. As shown in <FIG>, as the vaso-occlusive device <NUM> continues to be advanced out of the delivery catheter <NUM>, the distal anchoring loop <NUM> rotates and tumbles as the distal primary loop 108a enters the aneurysm and assumes its secondary configuration, while the distal tip <NUM> remains well within the aneurysm <NUM> and does not approach the neck <NUM> of the aneurysm <NUM>, thereby minimizing the risk that the distal end <NUM> or any other part of the vaso-occlusive device <NUM> will herniate out of the aneurysm. The smaller distal anchoring loop <NUM> mitigates the risk of associated with an oversized distal primary loop 108a by providing a leading structure that is largely unaffected by variations in stiffness of the wire <NUM> and stiffening suture, if any. <FIG> also shows the distal primary loop 108a effectively framing the aneurysm <NUM> providing a sufficient stability to allow the remaining primary loops <NUM> and the base portion <NUM> to deploy and assume the secondary configuration of the vaso-occlusive device <NUM> within aneurysm with relative ease, and eliminating the need to a clinician to manipulate the delivery catheter <NUM> during deployment. This also removes the dependence on the skill of the clinician for a successful deployment.

Moreover, the pyramidal shape of the primary loops <NUM> of vaso-occlusive device <NUM> has an 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 primary loops 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 primary loops <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 primary loops <NUM> is smaller than the overall height of the vaso-occlusive device <NUM> (e.g., <NUM> diameter of the primary loops 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> is illustrated 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 another 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 (<NUM>), comprising:
a coil formed of a wire (<NUM>) having a primary configuration in a constrained condition, the primary configuration having a proximal end and a distal end;
wherein the coil (<NUM>) assumes a secondary configuration in a relaxed, unconstrained condition, the secondary configuration comprising:
a primary portion (<NUM>) comprising a plurality of primary loops (<NUM>) , including a distal primary loop (108a) which is a distal-most loop of the primary loops (<NUM>), the distal primary loop (108a) having a proximal end and a distal end and a perimeter length from the proximal end to the distal end, the distal primary loop having turns lying in a first plane and planes substantially parallel to said first plane;
wherein
the secondary configuration further comprises a distal anchoring loop (<NUM>) connected to the distal end of the distal primary loop (108a), characterized in that the distal anchoring loop (<NUM>) has a substantially triangular shape, the distal anchoring loop has an overall length of <NUM>% to <NUM>% of the perimeter length of the distal primary loop, and in that the distal anchoring loop (<NUM>) is positioned within a projection of the distal primary loop (108a).