Patent Description:
The disclosure is directed to devices for delivering expandable stents. More particularly, the disclosure is directed to a device that selectively deploys a stent in a distal to proximal or a proximal to distal manner.

Delivery devices for expandable stents, such as those used in endoscopic applications, generally have an outer sheath that retracts to allow the stent to be expanded radially at the target site. Retraction of the outer sheath in the proximal direction exposes the stent in a distal to proximal direction, thus allows the distal end of the stent to be expanded first, providing a distal-to-proximal direction of expansion. This manner of deployment may allow the distal end of the stent to be placed in a particular location. However, the final location of the proximal end of the stent may not be known until the stent is fully expanded, particularly when the stent is self-expanding. When a specific location of the proximal end of the stent is desired, deploying the stent in a distal-to-proximal manner may require estimation of where the proximal end will reside upon complete expansion of the stent. Such an estimation may not have the desired precision needed for proper placement of the stent. There is an ongoing need to provide alternative delivery devices to selectively deploy stents in either a distal-to-proximal or proximal-to-distal manner.

<CIT>is related to a bi-directional stent delivery system including an inner elongate shaft, a radially expandable prosthesis disposed over the inner elongate shaft, an outer elongate shaft, and a shuttle sheath disposed over the radially expandable prosthesis. The distal portion of the inner shaft is releasably coupled to the distal portion of the shuttle sheath, and the distal portion of the outer shaft is releasably coupled the proximal portion of the shuttle sheath. A proximal coupling mechanism couples the distal end of the outer shaft with the proximal end of the shuttle sheath. A distal coupling mechanism couples the distal end of the shuttle sheath with the distal end of the inner shaft via a nosecone. Distal advancement of the inner shaft advances the shuttle sheath distally when the outer shaft is uncoupled from the shuttle sheath, thereby allowing the prosthesis to radially expand from a proximal end to a distal end. Proximal retraction of the outer shaft retracts the shuttle sheath proximally when the inner shaft is uncoupled from the shuttle sheath, thereby allowing the prosthesis to radially expand from a distal end to a proximal end thereof.

The present invention is directed to a stent delivery system as defined in the claims.

This disclosure provides design, material, and use alternatives for medical devices, including delivery systems.

A first example includes a stent delivery system. The system includes an elongated inner member extending between a distal tip and a proximal end, a stent surrounding a stent receiving region of the elongated inner member, the stent having a collapsed configuration and an expanded configuration. The system also includes an elongated outer sheath slidably disposed over the inner member, the outer sheath extending between a distal end and a proximal end, a stent sheath surrounding the stent to restrain the stent in the collapsed configuration, a proximal junction detachably coupling the distal end of the outer sheath to a proximal end of the stent sheath, the proximal junction being actuatable to selectively uncouple the distal end of the outer sheath from the proximal end of the stent sheath, and a distal junction detachably coupling a distal end of the stent sheath to the distal tip of the inner member, the distal junction being actuatable to selectively uncouple the stent sheath from the distal tip. The proximal junction is actuatable by rotating the inner member relative to the outer sheath in a first direction, and the distal junction is actuatable by rotating the inner member relative to the outer sheath in a second direction that is opposite the first direction, and at least a first stent expanding element disposed at at least one of the distal tip or the distal end of the outer sheath, the first stent expanding element having a radially retracted position and a radially elevated position.

Alternatively or additionally to any of the above examples, the distal tip includes a proximally extending threaded element, the distal end of the outer sheath includes a distally extending threaded element, and the stent sheath includes threaded cavities on the distal and proximal ends thereof, the threaded cavities configured to receive the proximally and distally extending threaded elements.

Alternatively or additionally to any of the above examples, the distally and proximally extending threaded elements are tapered.

Alternatively or additionally to any of the above examples, the distal and proximal threaded connections are each fully coupled and uncoupled by less than a <NUM> degree turn.

Alternatively or additionally to any of the above examples, the first stent expanding element includes a first elongated member having a first end attached to the proximally extending threaded element on the distal tip or to the distally extending threaded element on the distal end of the outer sheath, the first stent expanding element having a second free end opposite the first end.

Alternatively or additionally to any of the above examples, the stent delivery system further includes a first spring biasing the first stent expanding element in the elevated position.

Alternatively or additionally to any of the above examples, the first spring is disposed in a first groove extending longitudinally through the threading on the threaded element to which the first elongated member is attached, wherein the first elongated member is disposed within the first groove when the first stent expanding element is in the retracted position.

Alternatively or additionally to any of the above examples, the stent delivery system further includes a first slider element extending from a proximal region of the outer sheath to a distal end positioned adjacent the first end of the first elongated member, the first slider element configured to slide over a portion of the first elongated member, moving the first stent expanding element from the elevated position to the retracted position.

Alternatively or additionally to any of the above examples, the first stent expanding element is disposed on the distal tip, the system further comprising a second stent expanding element disposed on the distal end of the outer sheath.

Alternatively or additionally to any of the above examples, the first stent expanding element has a free end extending proximally and the second stent expanding element has a free end extending distally.

Alternatively or additionally to any of the above examples, the first stent expanding element is disposed on the distal tip, and the system further includes a second stent expanding element disposed at the distal end of the outer sheath, the second stent expanding element including a second elongated member having a first end attached to the distally extending threaded element on the distal end of the outer sheath and a second free end opposite its first end, the second stent expanding element having a radially retracted position and a radially elevated position, and a second slider element extending from a proximal region of the outer sheath to a distal end positioned adjacent the first end of the second elongated member, the second slider element configured to slide over a portion of the second elongated member, moving the second stent expanding element from the elevated position to the retracted position.

Alternatively or additionally to any of the above examples, the first and second sliders are independently moveable.

Alternatively or additionally to any of the above examples, the stent is deployable in a proximal-to-distal manner by uncoupling the proximal junction and moving the distal tip and stent sheath distally together relative to the stent.

Alternatively or additionally to any of the above examples, the stent is deployable in a distal-to-proximal manner by uncoupling the distal junction and moving the stent sheath and outer sheath proximally together relative to the stent.

Another example is a method of selectively deploying a stent in a proximal-to-distal manner or in a distal-to-proximal manner, including advancing a stent delivery system to a target location, the stent delivery system including an elongated inner member extending between a distal tip and a proximal end, a stent surrounding a stent receiving region of the elongated inner member and having a collapsed configuration and an expanded configuration, an elongated outer sheath slidably disposed over the inner member and extending between a distal end and a proximal end, a stent sheath surrounding the stent and removably coupled to the distal tip of the inner member and the distal end of the outer sheath, a first stent expanding element disposed at the distal tip, and a second stent expanding element disposed at the distal end of the outer sheath, the first and second stent expanding elements having a retracted position and an elevated position, the first and second stent expanding elements being biased in the elevated position. The method further includes deploying the stent in a distal-to-proximal manner by rotating the inner member relative to the outer sheath in a first rotational direction, to selectively decouple a distal end of the stent sheath from the distal tip, and moving the stent sheath coupled to the outer sheath proximally relative to the stent to uncover the stent, wherein moving the stent sheath proximally away from the distal tip causes the first stent expanding element to return to the biased elevated position and hold the stent as the stent sheath is moved proximally away from the stent. Alternatively the method includes deploying the stent in a proximal-to-distal manner by rotating the inner member relative to the outer sheath in a second rotational direction opposite the first rotational direction to selectively decouple the distal end of the outer sheath from a proximal end of the stent sheath, and moving the stent sheath coupled to the distal tip distally relative to the stent to uncover the stent, wherein moving the stent sheath distally away from the distal end of the outer sheath causes the second stent expanding element to return to the biased elevated position and hold the stent as the stent sheath is moved distally away from the stent.

Another example is a stent delivery system including an elongated inner member extending between a distal tip and a proximal end, a stent surrounding a stent receiving region of the elongated inner member, the stent having a collapsed configuration and an expanded configuration, an elongated outer sheath slidably disposed over the inner member, the outer sheath extending between a distal end and a proximal end, a stent sheath surrounding the stent to restrain the stent in the collapsed configuration. The system also includes a proximal junction detachably coupling the distal end of the outer sheath to a proximal end of the stent sheath, the proximal junction being actuatable to selectively uncouple the distal end of the outer sheath from the proximal end of the stent sheath, and a distal junction detachably coupling a distal end of the stent sheath to the distal tip of the inner member, the distal junction being actuatable to selectively uncouple the stent sheath from the distal tip. The proximal junction is actuatable by rotating the inner member relative to the outer sheath in a first direction, and the distal junction is actuatable by rotating the inner member relative to the outer sheath in a second direction that is opposite the first direction, and a first stent expanding element disposed at the distal tip and a second stent expanding element disposed at the distal end of the outer sheath, the first and second stent expanding elements each having a radially retracted position and a radially elevated position, wherein the first stent expanding element includes a first elongated member having a first end attached to the distal tip and a second free end, and the second stent expanding element includes a second elongated member having a first end attached to the distal end of the outer sheath and a second free end, wherein the first and second stent expanding elements are each biased in the elevated position.

Alternatively or additionally to any of the above examples, the stent delivery system further includes a first spring disposed in a first groove extending longitudinally through threading on a threaded element extending proximally from the distal tip, the first spring disposed under the first end of the first elongated member and biasing the first elongated member in the elevated position, wherein the first elongated member is disposed within the first groove when the first stent expanding element is in the retracted position, and a second spring disposed in a second groove extending longitudinally through threading on a threaded element extending distally from the distal end of the outer sheath, the second spring disposed under the first end of the second elongated member and biasing the second elongated member in the elevated position, wherein the second elongated member is disposed within the second groove when the second stent expanding element is in the retracted position.

Alternatively or additionally to any of the above examples, the stent delivery system further includes a first slider element extending from a proximal region of the outer sheath to a distal end positioned adjacent the first end of the first elongated member, the first slider element configured to slide over a portion of the first elongated member, moving the first stent expanding element from the elevated position to the retracted position, and a second slider element extending from a proximal region of the outer sheath to a distal end positioned adjacent the first end of the second elongated member, the second slider element configured to slide over a portion of the second elongated member, moving the second stent expanding element from the elevated position to the retracted position.

Alternatively or additionally to any of the above examples, the distal tip includes a proximally extending threaded element, the distal end of the outer sheath includes a distally extending threaded element, and the stent sheath includes threaded cavities on the distal and proximal ends thereof, the threaded cavities configured to receive the proximally and distally extending threaded elements, wherein the proximally and distally extending threaded elements are each tapered.

The Figures, and Detailed Description, which follow, more particularly exemplify some of these embodiments.

The invention is disclosed by the appended claims.

Definitions of certain terms are provided below and shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

Although some suitable dimensions, ranges and/or values pertaining to various components, features and/or specifications may be disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed.

As used in this specification and the appended claims, the singular forms "a," "an," and "the" include or otherwise refer to singular as well as plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed to include "and/or," unless the content clearly dictates otherwise.

It is noted that references in the specification to "an embodiment", "an example", "some embodiments", "some examples", "another embodiment", "another example" etc., indicate that the embodiment or example described may include one or more particular features, structures, and/or characteristics. However, such recitations do not necessarily mean that all embodiments or examples include the particular features, structures, and/or characteristics. Additionally, when particular features, structures, and/or characteristics are described in connection with one embodiment or example, it should be understood that such features, structures, and/or characteristics may also be used connection with other embodiments and examples whether or not explicitly described unless clearly stated to the contrary.

<FIG> illustrates a stent delivery device <NUM> that includes an outer sheath <NUM>, a stent sheath <NUM>, and an inner member <NUM> extending through and longitudinally slidable within the stent sheath <NUM> and the outer sheath <NUM>. The inner member <NUM> may include a distal tip <NUM> fixed to the distal end thereof. The outer sheath <NUM> may cover the majority of the device <NUM> excluding a portion of the distal end of the device <NUM> including the stent sheath <NUM> and the distal tip <NUM>. The outer sheath <NUM> may be characterized by a flexible tube which includes one or more lumens <NUM> extending therethrough. The proximal ends of the outer sheath <NUM> and inner member <NUM> may be attached, or otherwise coupled to components of a handle assembly <NUM>.

The inner member <NUM> may be a flexible tube extending through the lumen <NUM> of the outer sheath <NUM>, and through the hollow tubular stent sheath <NUM>. Guidance elements such as pull wires (not shown) may be disposed with the lumen <NUM>, or one or more additional lumens to help navigate the delivery device <NUM> and/or actuate one or more components of the delivery device <NUM>. The device <NUM> may be sized and configured for use in a range of medical applications, including, but not limited to, vascular applications or gastrointestinal applications, such as biliary, esophageal or colonic applications.

A proximal end of the inner member <NUM> may be fixedly attached, or otherwise coupled to a handle <NUM> of the handle assembly <NUM>. The inner member <NUM> may include a tubular portion extending between a proximal knob <NUM> and the distal tip <NUM>, with the tubular portion extending through the lumen <NUM> of the outer sheath <NUM> and through the stent sheath <NUM>. The inner member <NUM> may include at least one lumen <NUM>, such as a guidewire lumen, extending therethrough. For example, lumen <NUM> may extend through the entire length of the inner member <NUM> and tip <NUM>. In some instances, the stent delivery device <NUM> may be routed over a guidewire (not shown), which may be received through the lumen <NUM>.

The stent sheath <NUM> may be positioned longitudinally between the outer sheath <NUM> and the distal tip <NUM>. For example, the stent sheath <NUM> may be removably connected to the distal end <NUM> of the outer sheath <NUM> at a proximal junction <NUM> and removably connected to the proximal end <NUM> of the distal tip <NUM> at a distal junction <NUM>, as illustrated in <FIG>. The removable connection between the stent sheath <NUM> and the outer sheath <NUM> and the distal tip <NUM> may be a threaded connection, for example. In order to allow the proximal junction <NUM> and distal junction <NUM> to be separately and independently released, the threading of the connections may be reversed. For example, the distal junction <NUM> may have right hand threading <NUM> and the proximal junction <NUM> may have left hand threading <NUM>. In such a configuration, the distal junction <NUM> may be released by rotating the inner member <NUM> (and thus the distal tip <NUM>) via the handle <NUM> to the right or clockwise relative to the outer sheath <NUM> and the stent sheath <NUM>. The proximal junction <NUM> may be released by rotating the outer sheath <NUM> to the right or clockwise relative to the inner member handle <NUM>, the stent sheath <NUM>, the inner member <NUM>, and the distal tip <NUM>. The outer sheath <NUM> may be grasped directly at a proximal end thereof and the inner member <NUM> may be rotated by grasping and rotating the knob <NUM> or handle <NUM>. Alternatively, the distal junction <NUM> may have left hand threading <NUM> and the proximal junction <NUM> may have right hand threading <NUM>. In such a configuration, the direct of relative rotation between the components may be reversed. The oppositely threaded distal and proximal junctions <NUM>, <NUM> allow only one end of the stent sheath <NUM> (i.e., only one of the junctions) to be disconnected at a time, thus providing either distal-first (i.e., distal-to-proximal) or proximal-first (i.e., proximal-to-distal) delivery of the stent. In other words, the stent sheath <NUM> will remain connected to either the inner member <NUM> (via the distal tip <NUM>) or the outer sheath <NUM>, depending on which junction is separated.

In some instances, the handle assembly <NUM> may include a knob <NUM> disposed on the proximal end of the inner member <NUM>, as shown in <FIG>. Rotation of the knob <NUM> rotates the inner member <NUM> relative to the outer sheath <NUM>. Rotation may be provided by a circumferential slot <NUM> in the outer sheath <NUM>, as shown in <FIG> and discussed below.

The elements of one example of a handle assembly <NUM> are shown in <FIG> and include a coupler <NUM> disposed inside the outer sheath <NUM> and the handle <NUM> disposed around the outside of the outer sheath <NUM>. The handle <NUM> may have a pin <NUM> (see <FIG>) extending inward. The pin <NUM> may extend through the circumferential slot <NUM> in the outer sheath <NUM>, through an opening <NUM> in the wall of the coupler <NUM> and be fixedly attached to the inner member <NUM>. The inner member <NUM>, coupler <NUM>, and handle <NUM> are moveable together both rotationally and axially. The user may rotate the inner member <NUM> relative to the outer sheath <NUM> by rotating either the handle <NUM> or the knob <NUM> on the proximal end of the inner member <NUM>. The pin <NUM> travels around the circumferential slot <NUM> as the handle <NUM> rotates. The circumferential slot <NUM> is connected to and in communication with the longitudinal channel <NUM>. The inner member <NUM> may be slid axially within the outer sheath <NUM> by moving either the handle <NUM> or the knob <NUM>. The pin <NUM> travels along the longitudinal channel <NUM> as the handle <NUM> moves axially relative to the outer sheath <NUM>.

The coupler <NUM> may have a plurality of finger-like projections <NUM> extending outward from the outer surface. In some examples, the projections <NUM> disposed around a first half of the circumference of the coupler <NUM> are curved in a first direction and the projections <NUM> disposed around the second half of the circumference are curved in a second direction opposite the first direction, as shown in <FIG> and <FIG>. The coupler <NUM> may have at least one set of opposing projections <NUM>. In the example shown in <FIG>, the coupler <NUM> has two sets of opposing projections <NUM>, spaced apart along the longitudinal axis of the coupler <NUM>. The projections <NUM> slide along the inner surface of the outer sheath <NUM> when the coupler <NUM> is rotated relative to the outer sheath <NUM>. The projections <NUM> may allow the coupler <NUM> and attached inner member <NUM> to rotate relative to the outer sheath <NUM> while maintaining the radial position of the inner member <NUM> and coupler <NUM> within the outer sheath <NUM>.

The projections <NUM> may be sized to fit between two spaced apart rings of bumps <NUM> projecting from the inner surface of the outer sheath <NUM>, as shown in <FIG> and <FIG>. As shown in <FIG>, the bumps <NUM> may extend circumferentially around the inner surface of the outer sheath <NUM>. The bumps <NUM> may be spaced apart from one another circumferentially by a distance sufficient for the projections <NUM> to pass between adjacent bumps <NUM> when the coupler <NUM> is rotated to place the projections <NUM> between bumps <NUM>, and the inner member <NUM> with attached coupler <NUM> is moved distally, as shown in the difference between <FIG> and <FIG>. In some instances, a mark <NUM>, such as a dot, circle, line, arrow, or other marking, may be provided on the outer surface of the handle <NUM>, indicating the rotated positions in which the handle <NUM> and attached inner member <NUM> may be advanced distally. The marked positions are those in which the projections <NUM> on the coupler <NUM> are positioned between adjacent bumps <NUM>. A different marking <NUM> may be provided to indicate the start of a <NUM> degree rotation.

<FIG> shows the inner member <NUM> and attached coupler <NUM> and handle <NUM> in the proximal-most position, with the projections <NUM> disposed between circumferential rings of bumps <NUM> and axially adjacent to bumps <NUM>. In this position, the handle <NUM>, coupler <NUM>, and inner member <NUM> are rotatable relative to the outer sheath <NUM>, but are prevented from moving axially relative to the outer sheath <NUM> because the projections <NUM> are disposed axially adjacent the bumps <NUM>. When the handle <NUM> is rotated to a position in which the projections <NUM> are disposed between circumferentially adjacent bumps <NUM>, the handle <NUM> may then be moved distally, into the position shown in <FIG>.

<FIG> shows an alternative handle assembly, in which a channel <NUM> is disposed longitudinally along the inner member <NUM> and the outer sheath <NUM> has only a circumferential slot <NUM>. The handle assembly includes a handle <NUM> with a pin (not shown) that extends through the circumferential slot <NUM> in the outer sheath <NUM>, through the opening <NUM> in the coupler <NUM>. The pin slides along the longitudinal channel <NUM> in the inner member <NUM>, providing the axial movement of the inner member <NUM> relative to the outer sheath <NUM>. The outer sheath <NUM> may have a proximal knob <NUM>, and the coupler <NUM> may have projections <NUM> that slide along the inner surface of the outer sheath <NUM>. Rotational movement of the inner member <NUM> relative to the outer sheath <NUM> is provided by the pin connected to the handle <NUM> moving through the circumferential slot <NUM>. In this example, the handle <NUM> and coupler <NUM> move rotationally, but do not move axially relative to the outer sheath <NUM>. Axial movement is provided by moving the inner member <NUM>, with the pin connected to the handle <NUM> sliding along the channel <NUM>.

The threaded proximal end <NUM> of the distal tip <NUM> and the threaded distal end <NUM> of the outer sheath <NUM> may be substantially cylindrical in shape, as shown in <FIG>. Alternatively, the threaded proximal end <NUM> of the distal tip <NUM> on the inner member <NUM> and the threaded distal end <NUM> of the outer sheath <NUM> may both be tapered, with corresponding tapered threaded ends <NUM> on each end of the stent sheath <NUM>, as shown in <FIG>. It is noted that the threaded proximal end <NUM> of the distal tip <NUM> and the threaded distal end <NUM> of the outer sheath <NUM> are illustrated as male threaded portions (i.e., external threading), mating with female threaded portions (i.e., internal threading) of the tapered threaded ends <NUM> of the stent sheath <NUM>. However, in other embodiments the male and female threading of one or both of the junctions may be reversed, if desired. The tapered threaded ends provide for a quick release and reconnection between the threaded distal tip <NUM> or outer sheath <NUM> and the stent sheath <NUM> at the junctions. A reduced number of threads may also be used to provide for quick release. For example, a tapered threaded end and/or reduced thread number may provide a device in which the inner member <NUM> or outer sheath <NUM> may need to be turned one revolution (<NUM> degrees) or less to fully engage or disengage the threaded connection. In some examples, three-fourths of a turn (<NUM> degrees) or less, one-half of a turn (<NUM> degrees) or less, one-fourth of a turn (<NUM> degrees) or less, or less may be needed to fully engage or disengage the threaded connection.

The inner member <NUM> may include at least one stent receiving region <NUM> located along a distal region of the inner member <NUM> proximal of the distal tip <NUM>. A stent <NUM> may be disposed over and surround the inner member <NUM> in the stent receiving region <NUM>, such that the inner member <NUM> extends through the stent <NUM> and the stent sheath <NUM> surrounds the stent <NUM>. The stent <NUM> may be a self-expanding stent, configured to automatically expand to an expanded state from a constrained state when the stent sheath <NUM> is removed from the stent. The stent <NUM> may be made from self-expanding or shape memory alloys such as nitinol, spring steels, resilient polymer, or other materials known in the art for making self-expanding stents. The stent sheath <NUM> may hold the self-expanding stent <NUM> in its reduced diameter delivery configuration on the stent receiving region <NUM> until the stent sheath <NUM> is moved to uncover the stent <NUM>. In other examples, the stent <NUM> may be manually expanded.

The stent <NUM> may have one or more markers (not shown) such as radiopaque markers, disposed on the distal end <NUM>, proximal end <NUM>, or both ends. When markers are present on both the proximal and distal ends <NUM>, <NUM> of the stent <NUM>, the markers may be the same or different. Additionally, alignment markers (not shown) may be disposed on the outer sheath <NUM> and/or the inner member <NUM> to show rotational orientation and/or torqueing of the elements relative to each other. The alignment markers may be radiopaque and may be placed at any location along the length of the device, as desired.

Once either the distal junction <NUM> or the proximal junction <NUM> is decoupled (e.g., unscrewed or unthreaded), the stent <NUM> may be uncovered by or deployed from the stent sheath <NUM> by moving the distal tip <NUM> and the outer sheath <NUM> longitudinally away from each other. This longitudinal movement may be achieved by either holding the outer sheath <NUM> stationary and advancing the inner member <NUM> distally and/or holding the inner member <NUM> stationary and retracting the outer sheath <NUM> proximally.

A stent <NUM> may be deployed in a distal-to-proximal direction by decoupling (e.g., unscrewing or unthreading) the distal tip <NUM> from the stent sheath <NUM> at the distal junction <NUM> and then withdrawing the outer sheath <NUM> (along with the stent sheath <NUM>) proximally, as shown in <FIG>. Alternatively, the inner member <NUM> may be advanced distally, exposing the stent <NUM> from the distal end of the stent sheath <NUM>. The handle <NUM> may be rotated clockwise to rotate the distal tip <NUM> clockwise, as indicated by arrow <NUM> to decouple (e.g., unscrew or unthread) the distal junction <NUM>. Once the distal tip <NUM> is separated from the distal end <NUM> of the stent sheath <NUM>, the outer sheath <NUM> and the stent sheath <NUM> may be withdrawn proximally while the handle <NUM> is held stationary. The handle <NUM> may slide along the longitudinal channel <NUM> to position <NUM>'. As the stent sheath <NUM> moves proximally away from the distal tip <NUM>, the distal end <NUM> of the stent <NUM> may be initially uncovered and the stent <NUM> may expand in a distal-to-proximal direction. Once the stent <NUM> is fully uncovered and fully expanded, the inner member <NUM> and distal tip <NUM> may be retracted proximally through the expanded stent <NUM>, coupled (e.g., screwed or threaded) back onto the stent sheath <NUM>, and the device <NUM> may be removed from the patient leaving the stent <NUM> in place.

The handle <NUM> is rotatable relative to the outer sheath <NUM>, to provide rotational motion for the inner member <NUM> and the distal tip <NUM>. The inner member <NUM> may be advanced and retracted longitudinally relative to the outer sheath <NUM> by moving the handle <NUM> along a longitudinal channel <NUM> in the outer sheath <NUM> and/or handle assembly <NUM>. A portion of the handle <NUM> extends through the longitudinal channel <NUM> and is attached to the inner member <NUM>. The length of the longitudinal channel <NUM> may be sufficient to allow the handle <NUM> to be moved longitudinally to a position where the distal tip <NUM> is separated from the distal end <NUM> of the stent sheath <NUM> by a distance greater than the length of the stent <NUM>.

A stent <NUM> may be deployed in a proximal-to-distal direction by decoupling (e.g., unscrewing or unthreading) the outer sheath <NUM> from the stent sheath <NUM> at the proximal junction <NUM> and then the inner member <NUM> (along with the stent sheath <NUM>) may be advanced distally relative to the outer sheath <NUM>, as shown in <FIG>. Alternatively, the outer sheath <NUM> may be withdrawn proximally, exposing the stent <NUM> from the proximal end of the stent sheath <NUM>. The handle <NUM> may be rotated counter-clockwise to rotate the stent sheath <NUM> counter-clockwise, as indicated by arrow <NUM> to decouple (e.g., unscrew or unthread) the proximal junction <NUM>. Once the outer sheath <NUM> is separated from the proximal end <NUM> of the stent sheath <NUM>, the inner member <NUM> and attached stent sheath <NUM> may be moved distally, with the handle <NUM> moving along the longitudinal channel <NUM>, allowing the outer sheath <NUM> to remain stationary. Alternatively, the outer sheath <NUM> may be moved proximally. As the stent sheath <NUM> moves distally away from the outer sheath <NUM>, the proximal end <NUM> of the stent <NUM> may be initially uncovered and the stent <NUM> may expand in a proximal-to-distal direction. Once the stent <NUM> is fully uncovered and fully expanded, the inner member <NUM>, the distal tip <NUM>, and the stent sheath <NUM> may be retracted proximally through the expanded stent <NUM>, coupled (e.g., screwed or threaded) back onto the outer sheath <NUM>, and the device <NUM> removed from the patient leaving the stent <NUM> in place.

The stent <NUM> may be self-expandable or it may be manually expanded with a device such as a balloon (not shown). In some instances, a stent expander 160a (shown in <FIG>) may be provided on the proximal end <NUM> of the distal tip 122and/or a stent expander 160b (shown in <FIG>) may be provided on the distal end <NUM> of the outer sheath <NUM>. <FIG> illustrates features of the stent expander 160a/160b. The stent expander 160a/160b may include an elongate member attached at one end in a channel or groove 166a cut in the threaded distal end <NUM> of the outer sheath <NUM> and/or a channel or groove 166b cut in the threaded proximal end <NUM> of the distal dip <NUM>. A second, free end of the stent expander 160a/160b may include an enlarged tip 162a/162b which may be used to adjust the position of the stent <NUM> upon expansion. A spring 164b may be disposed under the stent expander 160b in the groove 166b, which biases the stent expander 160b in the elevated, radially outward position, as shown in <FIG>. In other embodiments, the stent expander 160b may be formed of a resilient material, with the stent expander 160b biased to the elevated, radially outward position. <FIG> and <FIG> illustrate the actuation of the stent expander 160b attached to the distal end <NUM> of the outer sheath <NUM>. It is noted that the stent expander 160a attached to the proximal end <NUM> of the distal tip <NUM> may be configured similarly. When the stent sheath <NUM> is disposed over the stent <NUM>, as shown in <FIG>, the stent sheath <NUM> presses the stent expander 160b down into the groove 166b, compressing the spring 164b so the stent expander 160b does not interfere with the threaded connection between the stent sheath <NUM> and the distal end <NUM> of the outer sheath <NUM>. When the stent sheath <NUM> is advanced distally from the stent <NUM>, the spring 164b expands, returning the stent expander 160b to its biased elevated position and the tip 162b, which may contact an inner surface of the proximal end region of the stent <NUM> and exerts a radially outwardly directed force on the stent <NUM>, aids the stent <NUM> in expanding in a proximal-first direction, as shown in <FIG>. In other instances, the resiliency of the stent expander 160b may cause the stent expander 160b to revert back towards the elevated positioned once unconstrained by the stent sheath <NUM>. The stent expander 160b may aid in expanding the stent <NUM>, whether the stent <NUM> is self-expanding or manually expanded. Further, the tip 162b of the stent expander 160b may be used to move the fully expanded stent <NUM> if adjustment to the final position of the stent <NUM> is desired. In some instances, the tip 162b of the stent expander 160b may contact an inner surface of the stent <NUM> as the stent sheath <NUM> is moved longitudinally relative to the stent <NUM> to facilitate deployment of the stent <NUM> from the stent sheath <NUM>.

Once the stent <NUM> is fully expanded, the stent expander 160b must be returned to the collapsed position within the groove 166b. For the stent expander 160b attached to the distal end <NUM> of the outer sheath <NUM>, this may be accomplished by moving an outer sheath slider <NUM> distally over the stent expander 160b (e.g., along a radially outward surface of the stent expander 160b), which may push the stent expander 160b radially inward down into the groove 166b. In <FIG>, the outer sheath slider <NUM> is in the retracted position, with the distal end of the outer sheath slider <NUM> just proximal of the stent expander 160b. A handle <NUM> or other actuator that extends through the outer sheath <NUM> may be connected to the proximal end of the outer sheath slider <NUM>, and configured to be advanced distally to move the outer sheath slider <NUM> distally along the stent expander 160b. The outer sheath slider <NUM> may be a substantially flat, thin element sufficiently rigid to force the stent expander 160b down into the groove 166b. The outer sheath slider <NUM> may move within a lumen in the outer sheath <NUM>. A channel <NUM> through the wall of the outer sheath <NUM> and/or the handle assembly <NUM> wall may allow the handle <NUM> to move back and forth longitudinally to actuate the outer sheath slider <NUM>.

<FIG> shows the stent expander 160a attached to the proximal end <NUM> of the distal tip <NUM>. The inner member <NUM> is shown extended distally away from the stent sheath <NUM>. The stent <NUM> has been removed for clarity. As on the distal end <NUM> of the outer sheath <NUM>, the stent expander 160a may be attached at one end in a channel or groove 166a cut in the threaded proximal end <NUM> of the distal tip <NUM> with a spring 164a under the stent expander 160a. The spring 164a may bias the stent expander 160a in an elevated, radially outward position, as shown in <FIG>. In other embodiments, the stent expander 160a may be formed of a resilient material, with the stent expander 160a biased to the elevated, radially outward position. An enlarged tip 162a may be attached to or otherwise provided at the free end of the stent expander 160a. As shown in the enlarged cross-sectional view of the distal tip <NUM> in <FIG>, an inner member slider <NUM> is disposed within the distal tip <NUM>. The inner member slider <NUM> may be attached to a slider extension <NUM> that is disposed within a second lumen <NUM> in the inner member <NUM>, adjacent the guidewire lumen <NUM>. Alternatively, the slider extension <NUM> may be disposed within the guidewire lumen <NUM>. The proximal end of the slider extension <NUM> may be attached to a handle <NUM> (shown in <FIG>) or other actuator that extends through a channel <NUM> in the outer sheath <NUM> and/or the handle assembly <NUM>. When the handle <NUM> is in the distal most position, the inner member slider <NUM> is distal of the stent expander 160a, as shown in <FIG>, and the stent expander 160a is in the elevated position. When the handle <NUM> is moved proximally, the inner member slider <NUM> may be moved proximally over the stent expander 160a (e.g., along a radially outward surface of the stent expander 160a), pushing the stent expander 160a down into the groove 166a. As with the outer sheath slider <NUM> on the outer sheath <NUM>, the inner member slider <NUM> and slider extension <NUM> on the distal tip <NUM> may be a substantially flat, thin element sufficiently rigid to force the stent expander 160a down into the groove 166a on the proximal end <NUM> of the distal tip <NUM>.

During distal-first expansion of the stent <NUM>, as shown in <FIG>, when the stent sheath <NUM> is withdrawn proximally from the stent <NUM>, the spring 164a expands, returning the stent expander 160a to its biased elevated position and the tip 162a, which may contact an inner surface of the distal end region of the stent <NUM> and exerts a radially outwardly directed force on the stent <NUM>, aids the stent <NUM> in expanding in a distal-first direction. In other instances, the resiliency of the stent expander 160a may cause the stent expander 160a to revert back towards the elevated positioned once unconstrained by the stent sheath <NUM>. The stent expander 160a may aid in expanding the stent <NUM>, whether the stent <NUM> is self-expanding or manually expanded. Further, the tip 162a of the stent expander 160a may be used to move the fully expanded stent <NUM> if adjustment to the final position of the stent <NUM> is desired.

As shown in <FIG>, the handle <NUM> connected to the outer sheath slider <NUM> is positioned near the distal end of the channel <NUM>, indicating the outer sheath slider <NUM> is positioned distally over the stent expander 160b and pressing the stent expander 160b into the groove 166b, thereby allowing the stent sheath <NUM> to slide off the proximal end of the stent <NUM>. The handle <NUM> connected to the inner member slider <NUM> is also positioned near the distal end of the channel <NUM>, indicating the inner member slider <NUM> is withdrawn distally of the stent expander 160a, allowing the stent expander 160a to be in the elevated position, as shown in <FIG>. The stent expander 160a is thus in position to aid the stent <NUM> in expanding in a distal-to-proximal direction. Once the stent <NUM> is fully expanded, the handle <NUM> may be moved proximally along the channel <NUM>, moving the inner member slider <NUM> proximally over and pressing the stent expander 160a into the groove 166a. With the stent expander 160a in the compressed position, the distal tip <NUM> may be withdrawn proximally through the expanded stent <NUM>. The distal tip <NUM> may then be coupled (e.g., screwed or threaded) back onto the distal end of the stent sheath <NUM> and the entire device may be withdrawn.

During proximal-to-distal expansion of the stent <NUM>, as shown in <FIG>, when the distal tip <NUM> and attached stent sheath <NUM> are advanced distally from the outer sheath <NUM>, the spring 164b may expand, returning the stent expander 160b to its biased elevated position and the tip 162b, which may contact an inner surface of the proximal end region of the stent <NUM> and exerts a radially outwardly directed force on the stent <NUM>, aids the stent <NUM> in expanding in a proximal-first direction. In other instances, the resiliency of the stent expander 160b may cause the stent expander 160b to revert back towards the elevated positioned once unconstrained by the stent sheath <NUM>. The stent expander 160b may aid in expanding the stent <NUM>, whether the stent <NUM> is self-expanding or manually expanded. Further, the tip 162b of the stent expander 160b may be used to move the fully expanded stent <NUM> if adjustment to the final position of the stent <NUM> is desired.

As shown in <FIG>, the handle <NUM> connected to the outer sheath slider <NUM> is positioned near the proximal end of the channel <NUM>, indicating the outer sheath slider <NUM> is withdrawn proximally of the stent expander 160b, allowing the stent expander 160b to be in the elevated position, as shown in <FIG>. The stent expander 160b is thus in position to aid the stent <NUM> in expanding in a proximal-to-distal direction. The handle <NUM> connected to the inner member slider <NUM> is also positioned near the proximal end of the channel <NUM>, indicating the inner member slider <NUM> is positioned proximally over the stent expander 160a and pressing the stent expander 160a into the groove 166a, thereby allowing the stent sheath <NUM> to slide off the distal end of the stent <NUM>.

Once the stent <NUM> is fully expanded, the handle <NUM> may be moved distally along the channel <NUM>, moving the outer sheath slider <NUM> distally over and pressing the stent expander 160b into the groove 166b. With the stent expander 160b in the compressed position, the distal tip <NUM> and attached stent sheath <NUM> may be withdrawn proximally through the expanded stent <NUM>. The distal tip <NUM> may then be coupled (e.g., screwed or threaded) back onto the distal end of the stent sheath <NUM> and the entire device may be withdrawn.

<FIG> is a top view of the outer sheath <NUM> and inner member <NUM>, but with the stent sheath <NUM> and stent <NUM> removed for clarity. Both the outer sheath slider <NUM> and inner member slider <NUM> are extended over their respective stent expanders 160b/160a, forcing the stent expanders 160b/160a into their respective grooves 166b/166a. This is indicated by the position of handles <NUM> and <NUM>. Handle <NUM>, connected to the outer sheath slider <NUM>, is positioned near the distal end of the channel <NUM>, indicating the outer sheath slider <NUM> is extended distally over the stent expander 160b on the distal end <NUM> of the outer sheath <NUM>. Handle <NUM>, connected to the inner member slider extension <NUM>, is near the proximal end of the channel <NUM>, indicating the inner member slider <NUM> is extended proximally over the stent expander 160a on the proximal end <NUM> of the distal tip <NUM>. The device, with a stent <NUM> loaded therein, may be advanced to a target location in a patient in such a configuration. In other instances, the device, with a stent <NUM> loaded therein, may be advanced to a target location in a patient, with the handles in the opposite positions such that the stent expander 160a and the stent expander 160b are pressed radially outward against an inner surface of the stent <NUM>. When the device is at the desired location, the user decides whether to deploy the stent <NUM> in the proximal-to-distal or distal-to-proximal direction, and thereafter actuate either the handle <NUM> or the handle <NUM> to facilitate deployment of the stent <NUM>.

The materials that can be used for the various components of the delivery device <NUM> (and/or other devices disclosed herein) and the various tubular members disclosed herein may include those commonly associated with medical devices. For simplicity purposes, the following discussion makes reference to outer sheath <NUM> and inner member <NUM> and other components of device <NUM>. However, this is not intended to limit the devices and methods described herein, as the discussion may be applied to other similar devices and/or components of devices or devices disclosed herein.

The various components of the devices/systems disclosed herein may include 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 304V, <NUM>, and 316LV 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: R30035 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: R30003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; combinations thereof; and the like; or any 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-<NUM>-isobutylene-<NUM>-styrene) (for example, SIBS and/or SIBS A), 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 at least some embodiments, portions or all of the delivery device <NUM> and/or other components of delivery system may 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 the user of the delivery device <NUM> in determining its location. 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 delivery device <NUM> to achieve the same result.

It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the disclosure.

Claim 1:
A stent delivery system comprising:
an elongated inner member (<NUM>) extending between a distal tip (<NUM>) and a proximal end;
a stent (<NUM>) surrounding a stent receiving region (<NUM>) of the elongated inner member (<NUM>), the stent (<NUM>) having a collapsed configuration and an expanded configuration;
an elongated outer sheath (<NUM>) slidably disposed over the inner member (<NUM>), the outer sheath (<NUM>) extending between a distal end (<NUM>) and a proximal end,
a stent sheath (<NUM>) surrounding the stent (<NUM>) to restrain the stent (<NUM>) in the collapsed configuration;
a proximal junction (<NUM>) detachably coupling the distal end (<NUM>) of the outer sheath (<NUM>) to a proximal end of the stent sheath (<NUM>), the proximal junction (<NUM>) being actuatable to selectively uncouple the distal end (<NUM>) of the outer sheath (<NUM>) from the proximal end of the stent sheath (<NUM>);
a distal junction (<NUM>) detachably coupling a distal end of the stent sheath (<NUM>) to the distal tip (<NUM>) of the inner member (<NUM>), the distal junction (<NUM>) being actuatable to selectively uncouple the stent sheath (<NUM>) from the distal tip (<NUM>);
wherein the proximal junction (<NUM>) is actuatable by rotating the inner member (<NUM>) relative to the outer sheath (<NUM>) in a first direction, and the distal junction (<NUM>) is actuatable by rotating the inner member (<NUM>) relative to the outer sheath (<NUM>) in a second direction that is opposite the first direction; characterised by
at least a first stent expanding element attached to at least one of the distal tip (<NUM>) or the distal end (<NUM>) of the outer sheath (<NUM>), the first stent expanding element having a radially retracted position and a radially elevated position.