Patent Description:
A wide variety of intracorporeal medical devices have been developed for medical use, for example, surgical and/or intravascular use. Some of these devices include guidewires, catheters, medical device delivery systems (e.g., for stents, grafts, replacement valves, etc.), and the like. These devices are manufactured by any one of a variety of different manufacturing methods and may be used according to any one of a variety of methods. There is an ongoing need to provide alternative medical devices as well as alternative methods for manufacturing and/or using medical devices.

<CIT> discloses a device for delivering an implant, including a delivery pusher, a moveable element, and first and second elongate members. Movement of the first elongate member in a first direction causes a time-delayed or lost motion movement of the second elongate member in the same direction, which releases the implant from the delivery pusher.

<CIT> discloses a distal protection device for use in a body lumen. The device includes a functional element, which may be a filter or an occlusive element, and means for controlling the movement and placement of the functional element along a guidewire.

<CIT> discloses a medical device for placing an embolic device at a predetermined site within a vessel of the body including a delivery catheter and a flexible pusher member slidably disposed within the lumen of the catheter. An embolic device is releasably disposed within the distal end of the pusher member and retained in place by a detachment fiber with a U-shaped distal section. When the embolic device is advanced to the predetermined site within the vessel, the detachment fiber is decoupled from the embolic device to thereby release the embolic device.

<CIT> discloses a medical device for placing an embolic device at a predetermined site within a vessel of the body including a delivery catheter and a flexible pusher member having a lumen therethrough and being slidably disposed within the lumen of the catheter. When the embolic device is advanced to the predetermined site within the vessel, a detachment member is withdrawn from an aperture to thereby release the embolic device at the treatment site.

<CIT> discloses an occlusive medical device system including a microcatheter and an elongate shaft. A release wire is configured to releasably attach the medical device to the distal end of the shaft at a release mechanism.

Any methods described herein do not form part of the claimed invention.

<FIG> illustrate an embodiment of a medical device system according to the present invention. <FIG> illustrates an example medical device which does not form part of the claimed invention.

While aspects of the disclosure are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiments described.

The following description should be read with reference to the drawings, which are not necessarily to scale, wherein like reference numerals indicate like elements throughout the several views. The detailed description and drawings are intended to illustrate but not limit the claimed invention. Those skilled in the art will recognize that the various elements described and/or shown may be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description and drawings illustrate example embodiments of the claimed invention. However, in the interest of clarity and ease of understanding, while every feature and/or element may not be shown in each drawing, the feature(s) and/or element(s) may be understood to be present regardless, unless otherwise specified.

Still other relative terms, such as "axial", "circumferential", "longitudinal", "lateral", "radial", etc. and/or variants thereof generally refer to direction and/or orientation relative to a central longitudinal axis of the disclosed structure or device.

The term "extent" may be understood to mean a greatest measurement of a stated or identified dimension, unless specifically referred to as a minimum extent. For example, "outer extent" may be understood to mean a maximum outer dimension, "radial extent" may be understood to mean a maximum radial dimension, "longitudinal extent" may be understood to mean a maximum longitudinal dimension, etc. Each instance of an "extent" may be different (e.g., axial, longitudinal, lateral, radial, circumferential, etc.) and will be apparent to the skilled person from the context of the individual usage. Generally, an "extent" may be considered a greatest possible dimension measured according to the intended usage. However, where referred to as a "minimum extent", the "extent" shall refer to a smallest possible dimension measured according to the intended usage. In some instances, an "extent" may generally be measured orthogonally within a plane and/or cross-section, but may be, as will be apparent from the particular context, measured differently - such as, but not limited to, angularly, radially, circumferentially (e.g., along an arc), etc..

That is, the various individual elements described below, even if not explicitly shown in a particular combination, are nevertheless contemplated as being combinable or arrangeable with each other to form other additional embodiments or to complement and/or enrich the described embodiment(s) within the scope of the claims, as would be understood by one of ordinary skill in the art.

Diseases and/or medical conditions that impact and/or are affected by the cardiovascular system are prevalent throughout the world. For example, some forms of arterial venous malformations (AVMs) may "feed" off of normal blood flow through the vascular system. Without being bound by theory, it is believed that it may be possible to treat, at least partially, arterial venous malformations and/or other diseases or conditions by starving them of normal, oxygen and/or nutrient-rich blood flow, thereby limiting their ability to grow and/or spread. Other examples of diseases or conditions that may benefit from vascular occlusion include, but are not limited to, bleeds, aneurysms, venous insufficiency, shutting off blood flow prior to organ resection, or preventing embolic bead reflux into branch vessels in the liver. Disclosed herein are medical devices that may be used within a portion of the cardiovascular system in order to treat and/or repair some arterial venous malformations and/or other diseases or conditions. The devices disclosed herein may also provide a number of additional desirable features and benefits as described in more detail below.

<FIG> and <FIG> illustrate aspects of an example medical device system <NUM>. The medical device system <NUM> includes an elongate shaft <NUM> having a lumen <NUM> (e.g., <FIG>) extending from a proximal end <NUM> of the elongate shaft <NUM> to a distal end <NUM> of the elongate shaft <NUM>. In some embodiments, the elongate shaft <NUM> may be a catheter, a hypotube, or other similar tubular structure. In some embodiments, at least a portion of the elongate shaft <NUM> may include micromachining, a plurality of cuts or weakened areas, some degree of material removal, etc. to provide increased flexibility along a length of the elongate shaft <NUM> for navigating tortuous vasculature. Some suitable but non-limiting materials for the elongate shaft <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

The medical device system <NUM> includes a proximal release wire (or a delivery system pull wire) <NUM> and a distal release wire (or a coupler pull wire) <NUM> (e.g., <FIG>) slidably disposed within the lumen <NUM> of the elongate shaft <NUM>. A medical device <NUM> may be disposed proximate the distal end <NUM> of the elongate shaft <NUM>. The proximal and distal release wires <NUM>, <NUM> may be axially slidable between an interlocked position and a released position relative to the medical device <NUM>, as will be described in more detail herein. The proximal and distal release wires <NUM>, <NUM> are configured to releasably attach the medical device <NUM> to the distal end <NUM> of the elongate shaft <NUM>. The medical device <NUM> may be configured to expand from a delivery configuration to a deployed configuration. For simplicity, the medical device <NUM> is illustrated herein as an embolic coil, but other suitable medical devices transported, delivered, used, released, etc. in a similar manner are also contemplated, including but not limited to, vascular occlusion device, stents, embolic filters, replacement heart valves, other occlusion devices, and/or other medical implants, etc. In some embodiments, the proximal and/or distal release wires <NUM>, <NUM> may be alternately and/or interchangeably referred to as a pull wire, an actuation wire, and/or a locking wire. The proximal and distal release wires <NUM>, <NUM> may generally be a solid wire or shaft, but may also be tubular in some embodiments. Some suitable but non-limiting materials for the release wire <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

In some embodiments, the medical device system <NUM> may include a microcatheter <NUM> sized and configured to deliver the medical device <NUM> to a treatment site in a delivery configuration. The elongate shaft <NUM> and the medical device <NUM> may be slidably disposed within a lumen <NUM> (e.g., <FIG>) of the microcatheter <NUM>. In some embodiments, the microcatheter <NUM> may facilitate percutaneous delivery of the medical device <NUM> to the treatment site. For reference only, the medical device <NUM> may be shown in the figures (e.g., <FIG>) in the delivery configuration or an at least partially-deployed configuration. The skilled person will recognize that the medical device <NUM> may be expanded and/or coiled upon itself when the medical device <NUM> is deployed. Some suitable but non-limiting materials for the microcatheter <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

<FIG> illustrates an enlarged perspective view of the distal end <NUM> of the elongate shaft <NUM> with the elongate shaft <NUM>, the medical device <NUM>, and the microcatheter <NUM> shown in transparency. The proximal release wire <NUM> extends distally from a proximal end <NUM> (e.g., <FIG>) configured to remain outside of the body to a distal end <NUM>. In some cases, the distal end <NUM> of the proximal release wire <NUM> may be positioned proximal to the medical device <NUM>. The distal end <NUM> is a looped distal end <NUM> forming a ring or proximal loop <NUM> defining an aperture <NUM>. The proximal loop <NUM> may have a generally oblong shape having an enclosed proximal end <NUM> and an enclosed distal end <NUM>. However, the proximal loop <NUM> may take other shapes as desired, such as, but not limited to, circular, rectangular, square, etc. The proximal loop <NUM> may generally extend generally parallel to a first plane.

The distal release wire <NUM> extends distally from a proximal end <NUM> to a distal end <NUM>. The distal end <NUM> of the distal release wire <NUM> may be slidably coupled with a release mechanism <NUM> as will be described in more detail herein. The proximal end <NUM> is positioned generally adjacent to the distal end <NUM> of the proximal release wire <NUM>. For example, the proximal end <NUM> of the distal release wire <NUM> may overlap a portion of the length of the distal end <NUM> of the proximal release wire <NUM>. The proximal end <NUM> is a looped proximal end forming a distal ring or loop <NUM> defining an aperture <NUM>. The distal loop <NUM> may have a generally oblong shape having an enclosed proximal end <NUM> and an enclosed distal end <NUM>. However, the distal loop <NUM> may take other shapes as desired, such as, but not limited to, circular, rectangular, square, etc. The distal loop <NUM> may generally extend generally parallel to a second plane which is generally orthogonal to the first plane.

In some embodiments the proximal loop <NUM> and the distal loop <NUM> may be formed by using metal pull wires and lap or tack welding one end of the wire in a loop. It is contemplated that some illustrative metals may include stainless steel, nitinol, and other as described in more detail below. If nitinol is used, heat setting can be utilized to form loops to the specific geometry desired.

The distal end <NUM> of the proximal release wire <NUM> is slidably coupled to the proximal end <NUM> of the distal release wire <NUM>. The distal end <NUM> of the proximal loop <NUM> of the proximal release wire <NUM> is disposed within the aperture <NUM> of the distal loop <NUM> of the distal release wire <NUM> in an interlocking arrangement. Similarly, the proximal end <NUM> of the distal loop <NUM> of the distal release wire <NUM> is disposed within the aperture <NUM> of the proximal loop <NUM> of the proximal release wire <NUM> to form a slip joint <NUM>. This may be allow the proximal release wire <NUM> and the distal release wire <NUM> to be slidably coupled to one another over a limited or predetermined axial distance (e.g., along a longitudinal axis of the system <NUM>). It is contemplated that the proximal release wire <NUM> and the distal release wire <NUM> may each move independently relative to one another over the limited axial distance. The length of the apertures <NUM>, <NUM> may determine how far the proximal release wire <NUM> and/or distal release wire <NUM> can slide independently before engaging the other component <NUM>, <NUM> and moving it as well.

The sliding arrangement of the proximal release wire <NUM> and the distal release wire <NUM> may help mitigate premature detachment of the medical device <NUM>. For example, when the delivery system <NUM> (and the medical device <NUM>) are proximally retracted (and at other times during use), the elongate shaft <NUM> can experience tensile loading. Said differently, the distal portion of the elongate shaft <NUM> may stretch which may cause the retention wire to prematurely detach from the medical device <NUM>. The proximal end <NUM> of the proximal release wire <NUM> (or a region adjacent thereto) may be coupled to the proximal end <NUM> of the elongate shaft <NUM> (or a region adjacent thereto) to limit or prevent movement of the proximal release wire <NUM> relative to the elongate shaft. However, this may cause the distal release wire <NUM> to stretch with the elongate shaft <NUM>. The sliding arrangement of the proximal release wire <NUM> and the distal release wire <NUM> may allow the proximal release wire <NUM> to move proximally (e.g., stretch) as the distal portion of the elongate shaft <NUM> stretches without exerting a proximal force on the distal release wire <NUM>. For example, if the proximal release wire <NUM> and distal release wire <NUM> may be arranged such that the distal end <NUM> of the proximal loop <NUM> of the proximal release wire <NUM> is in contact with or adjacent to the inner surface of the distal end <NUM> of the distal loop <NUM> of the distal release wire <NUM>. This may allow the proximal release wire <NUM> to move proximally the entire length of the aperture <NUM> of the distal loop <NUM> before the proximal force is applied to the distal release wire <NUM>. Once the inner surface of the distal end <NUM> of the proximal loop <NUM> engages the inner surface of the proximal end <NUM> of the distal loop <NUM>, the distal release wire <NUM> moves proximally with the proximal release wire <NUM>, as will be described in more detail herein.

<FIG> generally illustrate the medical device <NUM> being released from the elongate shaft <NUM>, such as at a treatment site, for example. In use, the microcatheter <NUM> of the medical device system <NUM> may be inserted into a patient's anatomy and a distal end of the microcatheter <NUM> may be guided and/or advanced to a location adjacent a treatment site. The medical device <NUM> disposed at and/or proximate the distal end <NUM> of the elongate shaft <NUM> may be inserted into a proximal end of the lumen <NUM>, disposed within the microcatheter <NUM>, and advanced through and/or with the microcatheter <NUM> to the treatment site. In some embodiments, the medical device <NUM> may be disposed within the lumen <NUM> of the microcatheter <NUM> proximate the distal end of the microcatheter <NUM>. In some embodiments, the medical device <NUM> may be disposed within the lumen <NUM> of the microcatheter <NUM> proximate the distal end of the microcatheter <NUM> prior to use and/or prior to inserting the microcatheter <NUM> into the patient's anatomy. Deployment and/or release of the medical device <NUM> may be performed selectively depending upon the type of medical device and/or the desired treatment process or method. When ready to deploy the medical device <NUM>, the elongate shaft <NUM> may be advanced and/or translated distally relative to the microcatheter <NUM> until the medical device <NUM> is exposed and/or disposed distal of the microcatheter <NUM>, as seen in <FIG>. Alternatively, the microcatheter <NUM> may be withdrawn relative to the elongate shaft <NUM> until the medical device <NUM> is exposed and/or disposed distal of the microcatheter <NUM>. For clarity, the microcatheter <NUM> is shown in a proximally retracted configuration. However, it should be understood that during navigation through the body, the microcatheter may be disposed over the medical device <NUM>.

A release mechanism <NUM> may releasably attach the medical device <NUM> to the distal end <NUM> of the elongate shaft <NUM>. In some embodiments, the elongate shaft <NUM> may include a first portion <NUM> of the release mechanism <NUM> fixedly attached to the distal end <NUM> of the elongate shaft <NUM> and the medical device <NUM> may include a second portion <NUM> of the release mechanism <NUM> fixedly attached to a proximal end of the medical device <NUM>. A distal end <NUM> of the distal release wire <NUM> may slidably engage with the first portion <NUM> of the release mechanism <NUM> and the second portion <NUM> of the release mechanism <NUM> in the interlocked position, as seen in <FIG>. The distal release wire <NUM> interlocks the first portion <NUM> of the release mechanism <NUM> with the second portion <NUM> of the release mechanism <NUM> when the proximal release wire <NUM> and the distal release wire <NUM> are in the delivery configuration, as seen in <FIG>. It should be noted that the delivery configuration does not require the distal end <NUM> of the proximal loop <NUM> to abut or contact the inner surface of the distal end <NUM> of the distal loop <NUM>, as shown. <FIG> illustrates the proximal release wire <NUM> and distal release wire <NUM> in an arrangement which allows for the greatest slip joint clearance <NUM>. The slip joint clearance <NUM> may dictate how much the elongate shaft <NUM> can stretch before motion of the distal release wire <NUM> is seen. The slip joint clearance <NUM> can be modified by changing a length of the proximal aperture <NUM> and/or the distal aperture <NUM>. In some cases, the apertures <NUM>, <NUM> may each have a length in the range of about <NUM> centimeters (cm) to about <NUM>, about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM>. It is contemplated that the apertures <NUM>, <NUM> may have lengths less than <NUM> or greater than <NUM> depending on the application. Further, the apertures <NUM>, <NUM> need not have the same lengths.

As the delivery system <NUM> is distally advanced to the treatment location, the elongate shaft <NUM> may start to stretch. In some instances, the proximal release wire <NUM> may be coupled to the elongate shaft <NUM> to prevent longitudinal movement of the proximal release wire <NUM> relative to the elongate shaft <NUM> during delivery. This may case the proximal release wire <NUM> to stretch with the elongate shaft <NUM>. <FIG> illustrates the slip joint <NUM> absorbing some of the stretch. As can be seen in <FIG>, the proximal release wire <NUM> has shifted in the proximal direction, as indicated by arrow <NUM>, while the distal release wire <NUM> remains longitudinally fixed. As can be seen in <FIG>, there is a length <NUM> of clearance in the slip joint <NUM>. However, the length <NUM> is less than the length <NUM> of the configuration illustrated in <FIG>. The movement of the proximal release wire <NUM> may be due to stretching or user actuation.

When detachment of the medical device <NUM> is desired, the user may uncouple the elongate shaft <NUM> and the proximal release wire <NUM>, if so attached, to allow for proximal retraction of the proximal release wire <NUM>. The proximal end <NUM> of the proximal release wire <NUM> may be proximally actuated over a first distance, as shown at arrow <NUM>, until a length of the clearance of the slip joint <NUM> has been used up, as shown in <FIG>. It is contemplated that the length of the clearance may be variable depending on the degree of stretching of the elongate shaft <NUM> and/or the original configuration of the proximal loop <NUM> relative to the distal loop <NUM>. Once the inner surface of the distal end <NUM> of the proximal loop <NUM> engages the inner surface of the proximal end <NUM> of the distal loop <NUM> further proximal movement over a second distance (e.g., beyond the predetermined distance of the clearance or greater than the first distance) of the proximal release wire <NUM> results in proximal actuation of the distal release wire <NUM> in concert with the proximal release wire <NUM>, as shown in <FIG>. In some cases, the distal loop <NUM> of the distal release wire <NUM> may have an interference fit with (or otherwise frictionally engage) the inner wall of the elongate shaft <NUM>. This may secure the distal release wire <NUM> until force is intentionally applied by the user to the proximal release wire <NUM>. Such an arrangement may help reduce passive migration of the distal release wire <NUM>.

It is contemplated that the release mechanism <NUM> may remain in an interlocked configuration until the distal release wire <NUM> has been proximally actuated by a length equal to or greater than the length of the release mechanism <NUM>. <FIG> and <FIG> illustrate the system <NUM> with the medical device <NUM> in a deployed configuration. For example, proximal actuation of the distal release wire <NUM> by a length less than a length of the release mechanism <NUM> may not be sufficient to release the medical device <NUM>. In at least some embodiments, the distal release wire <NUM> may be slidably disposed within the lumen <NUM> extending through the elongate shaft <NUM>, a first axial lumen extending through the first portion <NUM> of the release mechanism <NUM>, and a second axial lumen extending through the second portion <NUM> of the release mechanism <NUM>. It is contemplated that the release of the medical device <NUM> may be reversed at any axial location of the distal release wire <NUM> between the interlocked configuration and a fully released configuration (e.g., <FIG> and <FIG>). The first axial lumen of the first portion <NUM> and the second axial lumen of the second portion <NUM> may be substantially coaxial with the central longitudinal axis and/or the distal release wire <NUM> when the medical device <NUM> is releasably attached to the distal end <NUM> of the elongate shaft <NUM>. Some suitable but non-limiting materials for the release mechanism <NUM>, the first portion <NUM>, and the second portion <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

Referring back to <FIG> and <FIG>, the elongate shaft <NUM> may have sufficient length such that the proximal end <NUM> of the elongate shaft <NUM> and/or the proximal release wire <NUM> remains proximal of (e.g., extends proximally from) the microcatheter <NUM> when the medical device <NUM> is disposed distal of the microcatheter <NUM>. In use, the elongate shaft <NUM> may have sufficient length to reach from the treatment site to a position outside of the patient where the medical device system <NUM> may be manipulated by an operator (e.g., clinician, physician, user, etc.). After insertion of the medical device system <NUM> to the treatment site, the operator of the medical device system <NUM> may place a first hand on the proximal end <NUM> of the elongate shaft <NUM> and a second hand on the proximal end <NUM> of the proximal release wire <NUM> in order to manipulate the proximal release wire <NUM> and/or the distal release wire <NUM> to release the medical device <NUM>.

While not explicitly shown, the medical device system <NUM> may include an introducer configured to load the medical device <NUM> into the microcatheter <NUM>. The introducer may be a tubular member having a lumen extending from a proximal end to a distal end. The introducer may hold the medical device <NUM> to a reduced diameter and/or in a delivery configuration for loading into the microcatheter <NUM>. After loading the medical device <NUM> into the microcatheter <NUM>, the introducer may be proximally withdrawn over and relative to the elongate shaft <NUM> and removed from the medical device system <NUM>.

In use, a method of delivering the medical device <NUM> to a treatment site (e.g., a vein, an artery, etc.) may include inserting the microcatheter <NUM> into a patient's anatomy and guiding the distal end of the microcatheter <NUM> to a location adjacent the treatment site. The method may include inserting the medical device <NUM> disposed at and/or proximate the distal end <NUM> of the elongate shaft <NUM> into a proximal end of the lumen <NUM> disposed within the microcatheter <NUM>. In some embodiments, the medical device <NUM> may be inserted into the lumen <NUM> of the microcatheter <NUM> after the microcatheter <NUM> is inserted into the patient's anatomy. The method may include advancing the medical device <NUM> through the microcatheter <NUM> to the treatment site. The medical device <NUM> may be releasably attached to the distal end <NUM> of the elongate shaft <NUM> by a pull wire (e.g., proximal release wire <NUM> and/or distal release wire <NUM>, etc.) extending through the lumen <NUM> within the elongate shaft <NUM>. The proximal release wire <NUM> may extend proximally from the elongate shaft <NUM>, and the proximal release wire <NUM> may be releasably coupled to the elongate shaft <NUM>. Alternatively, in some embodiments, the medical device <NUM> may be inserted into the proximal end of the lumen <NUM> of the microcatheter <NUM> and advanced through the microcatheter <NUM> to a distal end of the microcatheter <NUM> before the microcatheter <NUM> is inserted into the patient's anatomy.

As discussed herein, the first portion <NUM> of the release mechanism <NUM> may be attached to the distal end <NUM> of the elongate shaft <NUM>, and the second portion <NUM> of the release mechanism <NUM> may be fixedly attached to a proximal end of the medical device <NUM>. The proximal release wire <NUM> and/or distal release wire <NUM> may be slidably disposed within the lumen <NUM> of the elongate shaft <NUM>, the first axial lumen of the first portion <NUM> of the release mechanism <NUM>, and the second axial lumen of the second portion <NUM> of the release mechanism <NUM>.

The method may include unlocking a retention mechanism between the proximal release wire <NUM> and the elongate shaft <NUM> to uncouple the proximal release wire <NUM> from the elongate shaft <NUM>. The method may further include translating the proximal release wire <NUM> proximally away from the proximal end <NUM> of the elongate shaft <NUM> while the elongate shaft <NUM> is maintained in a fixed position with respect to the treatment site to translate the proximal release wire <NUM> and/or the distal release wire <NUM> relative to the elongate shaft <NUM> and/or the release mechanism <NUM> to shift the distal release wire <NUM> from an interlocked position to a released position, thereby releasing the medical device <NUM> from the elongate shaft <NUM>.

The method may also include proximal withdrawal of the elongate shaft <NUM> and/or the microcatheter <NUM> from the treatment site. For example, in some embodiments, the elongate shaft <NUM> may be withdrawn proximally through the lumen <NUM> of the microcatheter <NUM> and removed, and the microcatheter <NUM> may then be withdrawn and/or removed from the patient's anatomy. In some embodiments, the elongate shaft <NUM> may be withdrawn proximally far enough for the distal end <NUM> of the elongate shaft <NUM> and/or the first portion <NUM> of the release mechanism <NUM> to be positioned within the distal end and/or the lumen <NUM> of the microcatheter <NUM>. The elongate shaft <NUM> and the microcatheter <NUM> may then be withdrawn together from the patient's anatomy.

In some embodiments, the elongate shaft <NUM> may be removed through the lumen <NUM> of the microcatheter <NUM>, and the microcatheter <NUM> may be left and/or held in place within the patient's anatomy. If needed, a second elongate shaft and associated second medical device may then be inserted into the proximal end of the lumen <NUM> of the microcatheter <NUM> and advanced to the treatment site for deployment. Additional repetitions of the device(s) described herein, as well as the described method steps, may be used as needed or desired for a particular procedure.

<FIG> illustrate aspects of an example medical device system <NUM>. <FIG> is a partial cross-sectional view of the distal end <NUM> of the elongate shaft <NUM>. The medical device system <NUM> may include an elongate shaft <NUM> having a lumen <NUM> extending from a proximal end (not explicitly shown) of the elongate shaft <NUM> to a distal end <NUM> of the elongate shaft <NUM>. The elongate shaft <NUM> may be similar in form and function to the elongate shaft <NUM> described herein. In some embodiments, the elongate shaft <NUM> may be a catheter, a hypotube, or other similar tubular structure. In some embodiments, at least a portion of the elongate shaft <NUM> may include micromachining, a plurality of cuts or weakened areas, some degree of material removal, etc. to provide increased flexibility along a length of the elongate shaft <NUM> for navigating tortuous vasculature. Some suitable but non-limiting materials for the elongate shaft <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

The medical device system <NUM> may include a proximal release wire (or a delivery system pull wire) <NUM> and a distal release wire (or a coupler pull wire) <NUM> slidably disposed within the lumen <NUM> of the elongate shaft <NUM>. A medical device <NUM> may be disposed proximate the distal end of the elongate shaft <NUM>. The medical device <NUM> may be similar in form and function to the medical device <NUM> described herein. The proximal and distal release wires <NUM>, <NUM> may be axially slidable between an interlocked position and a released position relative to the medical device <NUM>, as will be described in more detail herein. The proximal and distal release wires <NUM>, <NUM> may be configured to releasably attach the medical device <NUM> to the distal end <NUM> of the elongate shaft <NUM>.

The medical device <NUM> may be configured to expand from a delivery configuration to a deployed configuration. The medical device <NUM> may be a vascular occlusion device, but other suitable medical devices transported, delivered, used, released, etc. in a similar manner are also contemplated, including but not limited to, embolic coils, stents, embolic filters, replacement heart valves, other occlusion devices, and/or other medical implants, etc. In some embodiments, the proximal and/or distal release wires <NUM>, <NUM> may be alternately and/or interchangeably referred to as a pull wire, an actuation wire, and/or a locking wire. The proximal and/or distal release wires <NUM>, <NUM> may generally be a solid wire or shaft, but may also be tubular in some embodiments. Some suitable but non-limiting materials for the proximal and/or distal release wires <NUM>, <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

In some embodiments, the medical device system <NUM> may include a microcatheter <NUM> sized and configured to deliver the medical device to a treatment site in a delivery configuration. The elongate shaft <NUM> and the medical device <NUM> may be slidably disposed within a lumen <NUM> of the microcatheter <NUM>. In some embodiments, the microcatheter <NUM> may facilitate percutaneous delivery of the medical device to the treatment site. Some suitable but non-limiting materials for the microcatheter <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

The proximal release wire <NUM> extends distally from a proximal end (not explicitly shown) configured to remain outside of the body to a distal end <NUM>. In some cases, the distal end <NUM> of the proximal release wire <NUM> may be positioned proximal to the medical device <NUM>. The distal end <NUM> may be coiled to form a plurality of helical windings 228a, 228b, 228c (collectively, <NUM>) defining a lumen <NUM> extending therethrough. Said differently, the coiled distal end <NUM> may have a generally spring like structure with a lumen <NUM> extending through the coiled portion. The coiled distal end <NUM> may including any number of helical windings <NUM> desired, such as, but not limited to, less than one, one, two, three, four, or more. It is further contemplated that one or more of the helical windings <NUM> may form less than a complete <NUM>° revolution. In some cases, the one or more helical windings <NUM> may comprise a single winding have less than a complete <NUM>° revolution.

The distal release wire <NUM> extends distally from a proximal end <NUM> to a distal end <NUM>. The distal end <NUM> of the distal release wire <NUM> may be slidably coupled with a release mechanism <NUM> as will be described in more detail herein. The proximal end <NUM> may be positioned generally proximal to the distal end <NUM> of the proximal release wire <NUM>. For example, the proximal end <NUM> of the distal release wire <NUM> may overlap a portion of the length of the distal end <NUM> of the proximal release wire <NUM>. The proximal end <NUM> may be coiled to form a plurality of helical windings 242a, 242b, 242c (collectively, <NUM>) defining a lumen <NUM> extending therethrough. Said differently, the coiled proximal end <NUM> may have a generally spring like structure with a lumen <NUM> extending through the coiled portion. The coiled proximal end <NUM> may including any number of helical windings <NUM> desired, such as, but not limited to, less than one, one, two, three, four, or more. It is further contemplated that one or more of the helical windings <NUM> may form less than a complete <NUM>° revolution. In some cases, the one or more helical windings <NUM> may comprise a single winding have less than a complete <NUM>° revolution.

In some embodiments the coiled proximal end <NUM> and/or the coiled distal end <NUM> may be formed by using metal pull wires and forming and end thereof into a coil or helix. It is contemplated that some illustrative metals may include stainless steel, nitinol, and other as described in more detail below. If nitinol is used, heat setting can be utilized to form a coiled section to the specific geometry desired.

The coiled distal end <NUM> of the proximal release wire <NUM> may be slidably disposed over a linear portion <NUM> of the distal release wire <NUM> distal to the coiled proximal end <NUM> such that the linear portion <NUM> of the distal release wire <NUM> is slidably disposed within the lumen <NUM>. The coiled proximal end <NUM> may be slidably disposed over a linear portion <NUM> of the proximal release wire <NUM> proximal to the coiled distal end <NUM> such that the linear portion <NUM> of the distal release wire <NUM> is slidably disposed within the lumen <NUM>. This arrangement may form a slip joint <NUM>. In some cases, the configuration of the slip joint <NUM> may reduce the risk of the slip joint <NUM> binding during delivery. The distalmost winding 242c of the coiled proximal end <NUM> may be spaced a distance from the proximal-most winding 228a of the coiled distal end <NUM> to provide a slip joint clearance <NUM>. The slip joint clearance <NUM> may be the longitudinal distance the proximal release wire <NUM> can move (in at least the proximal direction) without simultaneously moving the distal release wire <NUM>. This may be allow the proximal release wire <NUM> and the distal release wire <NUM> to be slidably coupled to one another over a limited axial distance (e.g., along a longitudinal axis of the system <NUM>). It is contemplated that the proximal release wire <NUM> and the distal release wire <NUM> may each move independently relative to one another over the limited axial distance. The slip joint clearance <NUM> may determine how far the proximal release wire <NUM> and/or distal release wire <NUM> can slide independently before engaging the other component <NUM>, <NUM> and moving it as well. The slip joint clearance <NUM> can be modified by changing a position of the proximal release wire <NUM> relative to the distal release wire <NUM> and securing the proximal release wire <NUM> is said position relative to the elongate shaft <NUM>. In some cases, the slip joint clearance <NUM> may each have a length in the range of about <NUM> centimeters (cm) to about <NUM>, about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM>. It is contemplated that the slip joint clearance <NUM> may have lengths less than <NUM> or greater than <NUM> depending on the application.

The sliding arrangement of the proximal release wire <NUM> and the distal release wire <NUM> may help mitigate premature detachment of the medical device <NUM>. For example, when the delivery system <NUM> (and the medical device <NUM>) are proximally retracted (and at other times during use), the elongate shaft <NUM> can experience tensile loading. Said differently, the distal portion of the elongate shaft <NUM> may stretch which may cause the retention wire to prematurely detach from the medical device <NUM>. The proximal end of the proximal release wire <NUM> (or a region adjacent thereto) may be coupled to the proximal end of the elongate shaft <NUM> (or a region adjacent thereto) to limit or prevent movement of the proximal release wire <NUM> relative to the elongate shaft. However, this may cause the distal release wire <NUM> to stretch with the elongate shaft <NUM>. The sliding arrangement of the proximal release wire <NUM> and the distal release wire <NUM> may allow the proximal release wire <NUM> to move proximally (e.g., stretch) as the distal portion of the elongate shaft <NUM> stretches without exerting a proximal force on the distal release wire <NUM>. For example, if the proximal release wire <NUM> and distal release wire <NUM> may be arranged such that the distalmost winding 242c of the coiled proximal end <NUM> may be spaced a distance from the proximal-most winding 228a of the coiled distal end <NUM>. This may allow the proximal release wire <NUM> to move proximally the entire length of the slip joint clearance <NUM> before the proximal force is applied to the distal release wire <NUM>. Once the proximal-most winding 228a of the coiled distal end <NUM> engages the distalmost winding 242c of the coiled proximal end <NUM>, the distal release wire <NUM> moves proximally with the proximal release wire <NUM>, as will be described in more detail herein.

In use, the microcatheter <NUM> of the medical device system <NUM> may be inserted into a patient's anatomy and a distal end of the microcatheter <NUM> may be guided and/or advanced to a location adjacent a treatment site. The medical device <NUM> disposed at and/or proximate the distal end <NUM> of the elongate shaft <NUM> may be inserted into a proximal end of the lumen <NUM>, disposed within the microcatheter <NUM>, and advanced through and/or with the microcatheter <NUM> to the treatment site. In some embodiments, the medical device <NUM> may be disposed within the lumen <NUM> of the microcatheter <NUM> proximate the distal end of the microcatheter <NUM>. In some embodiments, the medical device <NUM> may be disposed within the lumen <NUM> of the microcatheter <NUM> proximate the distal end of the microcatheter <NUM> prior to use and/or prior to inserting the microcatheter <NUM> into the patient's anatomy. Deployment and/or release of the medical device <NUM> may be performed selectively depending upon the type of medical device and/or the desired treatment process or method. When ready to deploy the medical device <NUM>, the elongate shaft <NUM> may be advanced and/or translated distally relative to the microcatheter <NUM> until the medical device <NUM> is exposed and/or disposed distal of the microcatheter <NUM>. Alternatively, the microcatheter <NUM> may be withdrawn relative to the elongate shaft <NUM> until the medical device <NUM> is exposed and/or disposed distal of the microcatheter <NUM>. For clarity, the microcatheter <NUM> is shown in a proximally retracted configuration. However, it should be understood that during navigation through the body, the microcatheter may be disposed over the medical device <NUM>.

A release mechanism <NUM> may releasably attach the medical device <NUM> to the distal end <NUM> of the elongate shaft <NUM>. In some embodiments, the elongate shaft <NUM> may include a first portion <NUM> of the release mechanism <NUM> fixedly attached to the distal end <NUM> of the elongate shaft <NUM> and the medical device <NUM> may include a second portion <NUM> of the release mechanism <NUM> fixedly attached to a proximal end of the medical device <NUM>. A distal end <NUM> of the distal release wire <NUM> may slidably engage with the first portion <NUM> of the release mechanism <NUM> and the second portion <NUM> of the release mechanism <NUM> in the interlocked position, as seen in <FIG>. The distal release wire <NUM> interlocks the first portion <NUM> of the release mechanism <NUM> with the second portion <NUM> of the release mechanism <NUM> when the proximal release wire <NUM> and the distal release wire <NUM> are in the delivery configuration, as seen in <FIG>.

As the delivery system <NUM> is distally advanced to the treatment location, the elongate shaft <NUM> may start to stretch. In some instances, the proximal release wire <NUM> may be coupled to the elongate shaft <NUM> to prevent longitudinal movement of the proximal release wire <NUM> relative to the elongate shaft <NUM> during delivery. This may case the proximal release wire <NUM> to stretch with the elongate shaft <NUM>. While not explicitly shown, as the proximal release wire <NUM> is shifted in the proximal direction the distal release wire <NUM> may remain longitudinally fixed thus reducing the distance of the slip joint clearance <NUM>.

When detachment of the medical device <NUM> is desired, the user may uncouple the elongate shaft <NUM> and the proximal release wire <NUM>, if so attached, to allow for proximal retraction of the proximal release wire <NUM>. The proximal end (not explicitly shown) of the proximal release wire <NUM> may be proximally actuated over a first distance until a length of the clearance <NUM> of the slip joint <NUM> has been used up. It is contemplated that the length of the clearance <NUM> may be variable depending on the degree of stretching of the elongate shaft <NUM> and/or the original configuration of the coiled distal end <NUM> relative to the coiled proximal end <NUM>. Once the proximal-most winding 228a of the proximal release wire <NUM> engages the distalmost winding 242c of the distal release wire <NUM> further proximal movement of the proximal release wire <NUM> over a second distance (e.g., beyond the predetermined distance of the clearance or greater than the first distance) results in proximal actuation of the distal release wire <NUM> with the proximal release wire <NUM>. In some cases, the coiled proximal end <NUM> of the distal release wire <NUM> may have an interference fit with (or otherwise frictionally engage) the inner wall of the elongate shaft <NUM>. This may secure the distal release wire <NUM> until force is intentionally applied by the user to the proximal release wire <NUM>. Such an arrangement may help reduce passive migration of the distal release wire <NUM>.

It is contemplated that the release mechanism <NUM> may remain in an interlocked configuration until the distal release wire <NUM> has been proximally actuated by a length equal to or greater than the length of the release mechanism <NUM>. For example, proximal actuation of the distal release wire <NUM> by a length less than a length of the release mechanism <NUM> may not be sufficient to release the medical device <NUM>. In at least some embodiments, the distal release wire <NUM> may be slidably disposed within the lumen <NUM> extending through the elongate shaft <NUM>, a first axial lumen extending through the first portion <NUM> of the release mechanism <NUM>, and a second axial lumen extending through the second portion <NUM> of the release mechanism <NUM>. It is contemplated that the release of the medical device <NUM> may be reversed at any axial location of the distal release wire <NUM> between the interlocked configuration and a fully released configuration. The first axial lumen of the first portion <NUM> and the second axial lumen of the second portion <NUM> may be substantially coaxial with the central longitudinal axis and/or the distal release wire <NUM> when the medical device <NUM> is releasably attached to the distal end <NUM> of the elongate shaft <NUM>. Some suitable but non-limiting materials for the release mechanism <NUM>, the first portion <NUM>, and the second portion <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

The elongate shaft <NUM> may have sufficient length such that the proximal end of the elongate shaft <NUM> and/or the proximal release wire <NUM> remains proximal of (e.g., extends proximally from) the microcatheter <NUM> when the medical device <NUM> is disposed distal of the microcatheter <NUM>. In use, the elongate shaft <NUM> may have sufficient length to reach from the treatment site to a position outside of the patient where the medical device system <NUM> may be manipulated by an operator (e.g., clinician, physician, user, etc.). After insertion of the medical device system <NUM> to the treatment site, the operator of the medical device system <NUM> may place a first hand on the proximal end of the elongate shaft <NUM> and a second hand on the proximal end of the proximal release wire <NUM> in order to manipulate the proximal release wire <NUM> and/or the distal release wire <NUM> to release the medical device <NUM>.

The method may include unlocking a retention mechanism between the proximal release wire <NUM> and the elongate shaft <NUM> to uncouple the proximal release wire <NUM> from the elongate shaft <NUM>. The method may further include translating the proximal release wire <NUM> proximally away from the proximal end of the elongate shaft <NUM> while the elongate shaft <NUM> is maintained in a fixed position with respect to the treatment site to translate the proximal release wire <NUM> and/or the distal release wire <NUM> relative to the elongate shaft <NUM> and/or the release mechanism <NUM> to shift the distal release wire <NUM> from an interlocked position to a released position, thereby releasing the medical device <NUM> from the elongate shaft <NUM>.

The materials that can be used for the various components of the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, the release mechanism <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. (and/or other systems disclosed herein) and the various elements thereof disclosed herein may include those commonly associated with medical devices. For simplicity purposes, the following discussion makes reference to the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, the release mechanism <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. However, this is not intended to limit the devices and methods described herein, as the discussion may be applied to other elements, members, components, or devices disclosed herein, such as, but not limited to, the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, the release mechanism <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. and/or elements or components thereof.

In some embodiments, the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, the release mechanism <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc., and/or components thereof, may be made from a metal, metal alloy, polymer (some examples of which are disclosed below), a metal-polymer composite, ceramics, combinations thereof, and the like, or other suitable material. Some examples of suitable metals and metal alloys include stainless steel, such as 444V, <NUM>, and 314LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® <NUM>, UNS: N06022 such as HASTELLOY® C-<NUM>®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® <NUM>, NICKELVAC® <NUM>, NICORROS® <NUM>, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; platinum; palladium; gold; combinations thereof; and the like; or any other suitable material.

For example, across a broad temperature range, the linear elastic and/or non-super-elastic nickel-titanium alloy maintains its linear elastic and/or non-super-elastic characteristics and/or properties.

In at least some embodiments, portions or all of the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc., and/or components thereof, may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids a user in determining the location of the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloy, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and/or coils may also be incorporated into the design of the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. to achieve the same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MRI) compatibility is imparted the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. For example, the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc., and/or components or portions thereof, may be made of a material that does not substantially distort the image and create substantial artifacts (e.g., gaps in the image). Certain ferromagnetic materials, for example, may not be suitable because they may create artifacts in an MRI image. The medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc., or portions thereof, may also be made from a material that the MRI machine can image. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such as ELGILOY®, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as MP35-N® and the like), nitinol, and the like, and others.

In some embodiments, the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc., and/or portions thereof, may be made from or include a polymer or other suitable material. Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane (for example, Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex® high-density polyethylene, Marlex® low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-<NUM> (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like. In some embodiments the sheath can be blended with a liquid crystal polymer (LCP). For example, the mixture can contain up to about <NUM> percent LCP.

In some embodiments, the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. disclosed herein may include a fabric material disposed over or within the structure. The fabric material may be composed of a biocompatible material, such a polymeric material or biomaterial, adapted to promote tissue ingrowth. In some embodiments, the fabric material may include a bioabsorbable material. Some examples of suitable fabric materials include, but are not limited to, polyethylene glycol (PEG), nylon, polytetrafluoroethylene (PTFE, ePTFE), a polyolefinic material such as a polyethylene, a polypropylene, polyester, polyurethane, and/or blends or combinations thereof.

In some embodiments, the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. may include and/or be formed from a textile material. Some examples of suitable textile materials may include synthetic yarns that may be flat, shaped, twisted, textured, pre-shrunk or un-shrunk. Synthetic biocompatible yarns suitable for use in the present invention include, but are not limited to, polyesters, including polyethylene terephthalate (PET) polyesters, polypropylenes, polyethylenes, polyurethanes, polyolefins, polyvinyls, polymethylacetates, polyamides, naphthalene dicarboxylene derivatives, natural silk, and polytetrafluoroethylenes. Moreover, at least one of the synthetic yarns may be a metallic yarn or a glass or ceramic yarn or fiber. Useful metallic yarns include those yarns made from or containing stainless steel, platinum, gold, titanium, tantalum or a Ni-Co-Cr-based alloy. The yarns may further include carbon, glass or ceramic fibers. Desirably, the yarns are made from thermoplastic materials including, but not limited to, polyesters, polypropylenes, polyethylenes, polyurethanes, polynaphthalenes, polytetrafluoroethylenes, and the like. The yarns may be of the multifilament, monofilament, or spun-types. The type and denier of the yarn chosen may be selected in a manner which forms a biocompatible and implantable prosthesis and, more particularly, a vascular structure having desirable properties.

In some embodiments, the medical device system <NUM>, <NUM>, the elongate shaft <NUM>, <NUM>, the release wires <NUM>, <NUM>, <NUM>, <NUM>, the medical device <NUM>, <NUM>, the release mechanism <NUM>, <NUM>, the introducer, and/or the microcatheter <NUM>, <NUM>, etc. may include and/or be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents may include anti-thrombogenic agents (such as heparin, heparin derivatives, urokinase, and PPack (dextrophenylalanine proline arginine chloromethylketone)); anti-proliferative agents (such as enoxaparin, angiopeptin, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine); antineoplastic/antiproliferative/anti-mitotic agents (such as paclitaxel, <NUM>-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin and thymidine kinase inhibitors); anesthetic agents (such as lidocaine, bupivacaine, and ropivacaine); anti-coagulants (such as D-Phe-Pro-Arg chloromethyl ketone, an RGD peptide-containing compound, heparin, anti-thrombin compounds, platelet receptor antagonists, anti-thrombin antibodies, anti-platelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick antiplatelet peptides); vascular cell growth promoters (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional activators, and translational promoters); vascular cell growth inhibitors (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translational repressors, replication inhibitors, inhibitory antibodies, antibodies directed against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, bifunctional molecules consisting of an antibody and a cytotoxin); cholesterol-lowering agents; vasodilating agents; and agents which interfere with endogenous vascoactive mechanisms.

Claim 1:
A medical device system (<NUM>) comprising:
an elongate shaft (<NUM>) having a lumen (<NUM>) extending from a proximal end (<NUM>) of the elongate shaft (<NUM>) to a distal end (<NUM>) of the elongate shaft (<NUM>);
a proximal release wire (<NUM>) extending distally from a proximal end (<NUM>) configured to remain outside a body to a distal end (<NUM>) and slidably disposed within the lumen (<NUM>) of the elongate shaft (<NUM>); and
a distal release wire (<NUM>) extending distally from a proximal end (<NUM>) to a distal end (<NUM>) and slidably disposed within the lumen (<NUM>) of the elongate shaft (<NUM>), the proximal end (<NUM>) of the distal release wire (<NUM>) slidably coupled to the distal end (<NUM>) of the proximal release wire (<NUM>),
wherein the distal release wire (<NUM>) is configured to releasably attach a medical device (<NUM>) to the distal end (<NUM>) of the elongate shaft (<NUM>),
wherein the distal end (<NUM>) of the proximal release wire (<NUM>) is formed into a proximal loop (<NUM>) and the proximal end (<NUM>) of the distal release wire (<NUM>) is formed into a distal loop (<NUM>),
wherein the proximal loop (<NUM>) and the distal loop (<NUM>) are slidably coupled, and
wherein an inner surface of a distal end (<NUM>) of the proximal loop (<NUM>) is configured to engage an inner surface of a proximal end (<NUM>) of the distal loop (<NUM>) upon proximal actuation of the proximal release wire (<NUM>).