Proximal and distal release delivery system

Stent delivery device includes an inner member having a distal tip, a stent disposed over a stent receiving region of the inner member, an outer sheath slidable over the inner member, a stent sheath removably coupled to both the distal tip and a distal end of the outer sheath, and a stent expanding element attached to the distal tip and/or the distal end of the outer sheath. The stent expanding element is biased in an elevated position and aids expansion of the stent when the stent sheath is removed. The stent delivery device includes a proximal junction removably coupling the distal end of the outer sheath to the stent sheath, and a proximal junction removably coupling the stent sheath to the distal tip. Each of the proximal and distal junctions are separately actuatable to decouple the stent sheath from either the distal tip or the outer sheath.

TECHNICAL FIELD

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.

BACKGROUND

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.

BRIEF SUMMARY

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 360 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 first and second sliders are independently moveable.

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 above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The Figures, and Detailed Description, which follow, more particularly exemplify some of these embodiments.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. 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.

All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may be indicative as including numbers that are rounded to the nearest significant figure. The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

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.

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. 1illustrates a stent delivery device100that includes an outer sheath110, a stent sheath105, and an inner member120extending through and longitudinally slidable within the stent sheath105and the outer sheath110. The inner member120may include a distal tip122fixed to the distal end thereof. The outer sheath110may cover the majority of the device100excluding a portion of the distal end of the device100including the stent sheath105and the distal tip122. The outer sheath110may be characterized by a flexible tube which includes one or more lumens114extending therethrough. The proximal ends of the outer sheath110and inner member120may be attached, or otherwise coupled to components of a handle assembly150.

The inner member120may be a flexible tube extending through the lumen114of the outer sheath110, and through the hollow tubular stent sheath105. Guidance elements such as pull wires (not shown) may be disposed with the lumen114, or one or more additional lumens to help navigate the delivery device100and/or actuate one or more components of the delivery device100. The device100may 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 member120may be fixedly attached, or otherwise coupled to a handle130of the handle assembly150. The inner member120may include a tubular portion extending between a proximal knob152and the distal tip122, with the tubular portion extending through the lumen114of the outer sheath110and through the stent sheath105. The inner member120may include at least one lumen124, such as a guidewire lumen, extending therethrough. For example, lumen124may extend through the entire length of the inner member120and tip122. In some instances, the stent delivery device100may be routed over a guidewire (not shown), which may be received through the lumen124.

The stent sheath105may be positioned longitudinally between the outer sheath110and the distal tip122. For example, the stent sheath105may be removably connected to the distal end112of the outer sheath110at a proximal junction145and removably connected to the proximal end123of the distal tip122at a distal junction140, as illustrated inFIG. 1. The removable connection between the stent sheath105and the outer sheath110and the distal tip122may be a threaded connection, for example. In order to allow the proximal junction145and distal junction140to be separately and independently released, the threading of the connections may be reversed. For example, the distal junction140may have right hand threading128and the proximal junction145may have left hand threading118. In such a configuration, the distal junction140may be released by rotating the inner member120(and thus the distal tip122) via the handle130to the right or clockwise relative to the outer sheath110and the stent sheath105. The proximal junction145may be released by rotating the outer sheath110to the right or clockwise relative to the inner member handle130, the stent sheath105, the inner member120, and the distal tip122. The outer sheath110may be grasped directly at a proximal end thereof and the inner member120may be rotated by grasping and rotating the knob152or handle130. Alternatively, the distal junction140may have left hand threading128and the proximal junction145may have right hand threading118. In such a configuration, the direct of relative rotation between the components may be reversed. The oppositely threaded distal and proximal junctions140,145allow only one end of the stent sheath105(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 sheath105will remain connected to either the inner member120(via the distal tip122) or the outer sheath110, depending on which junction is separated.

In some instances, the handle assembly150may include a knob152disposed on the proximal end of the inner member120, as shown inFIG. 2. Rotation of the knob152rotates the inner member120relative to the outer sheath110. Rotation may be provided by a circumferential slot115in the outer sheath110, as shown inFIG. 3and discussed below.

The elements of one example of a handle assembly150are shown inFIG. 3and include a coupler154disposed inside the outer sheath110and the handle130disposed around the outside of the outer sheath110. The handle130may have a pin132(seeFIG. 4) extending inward. The pin132may extend through the circumferential slot115in the outer sheath110, through an opening156in the wall of the coupler154and be fixedly attached to the inner member120. The inner member120, coupler154, and handle130are moveable together both rotationally and axially. The user may rotate the inner member120relative to the outer sheath110by rotating either the handle130or the knob152on the proximal end of the inner member120. The pin132travels around the circumferential slot115as the handle130rotates. The circumferential slot115is connected to and in communication with the longitudinal channel111. The inner member120may be slid axially within the outer sheath110by moving either the handle130or the knob152. The pin132travels along the longitudinal channel111as the handle130moves axially relative to the outer sheath110.

The coupler154may have a plurality of finger-like projections158extending outward from the outer surface. In some examples, the projections158disposed around a first half of the circumference of the coupler154are curved in a first direction and the projections158disposed around the second half of the circumference are curved in a second direction opposite the first direction, as shown inFIGS. 3 and 4. The coupler154may have at least one set of opposing projections158. In the example shown inFIG. 3, the coupler154has two sets of opposing projections158, spaced apart along the longitudinal axis of the coupler154. The projections158slide along the inner surface of the outer sheath110when the coupler154is rotated relative to the outer sheath110. The projections158may allow the coupler154and attached inner member120to rotate relative to the outer sheath110while maintaining the radial position of the inner member120and coupler154within the outer sheath110.

The projections158may be sized to fit between two spaced apart rings of bumps113projecting from the inner surface of the outer sheath110, as shown inFIGS. 4 and 5. As shown inFIG. 4, the bumps113may extend circumferentially around the inner surface of the outer sheath110. The bumps113may be spaced apart from one another circumferentially by a distance sufficient for the projections158to pass between adjacent bumps113when the coupler154is rotated to place the projections158between bumps113, and the inner member120with attached coupler154is moved distally, as shown in the difference betweenFIGS. 5 and 6. In some instances, a mark134, such as a dot, circle, line, arrow, or other marking, may be provided on the outer surface of the handle130, indicating the rotated positions in which the handle130and attached inner member120may be advanced distally. The marked positions are those in which the projections158on the coupler154are positioned between adjacent bumps113. A different marking136may be provided to indicate the start of a 360 degree rotation.

FIG. 5shows the inner member120and attached coupler154and handle130in the proximal-most position, with the projections158disposed between circumferential rings of bumps113and axially adjacent to bumps113. In this position, the handle130, coupler154, and inner member120are rotatable relative to the outer sheath110, but are prevented from moving axially relative to the outer sheath110because the projections158are disposed axially adjacent the bumps113. When the handle130is rotated to a position in which the projections158are disposed between circumferentially adjacent bumps113, the handle130may then be moved distally, into the position shown inFIG. 6.

FIG. 7shows an alternative handle assembly, in which a channel1111is disposed longitudinally along the inner member1120and the outer sheath1110has only a circumferential slot1115. The handle assembly includes a handle1130with a pin (not shown) that extends through the circumferential slot1115in the outer sheath1110, through the opening1156in the coupler1154. The pin slides along the longitudinal channel1111in the inner member1120, providing the axial movement of the inner member1120relative to the outer sheath1110. The outer sheath1110may have a proximal knob1152, and the coupler154may have projections1158that slide along the inner surface of the outer sheath1110. Rotational movement of the inner member1120relative to the outer sheath1110is provided by the pin connected to the handle1130moving through the circumferential slot1115. In this example, the handle1130and coupler1154move rotationally, but do not move axially relative to the outer sheath1110. Axial movement is provided by moving the inner member1120, with the pin connected to the handle1130sliding along the channel1111.

The threaded proximal end123of the distal tip122and the threaded distal end112of the outer sheath110may be substantially cylindrical in shape, as shown inFIG. 1. Alternatively, the threaded proximal end2123of the distal tip2122on the inner member2120and the threaded distal end2112of the outer sheath2110may both be tapered, with corresponding tapered threaded ends2103on each end of the stent sheath2105, as shown inFIG. 8. It is noted that the threaded proximal end2123of the distal tip2122and the threaded distal end2112of the outer sheath2110are illustrated as male threaded portions (i.e., external threading), mating with female threaded portions (i.e., internal threading) of the tapered threaded ends2103of the stent sheath2105. 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 tip2122or outer sheath2110and the stent sheath2105at 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 member2120or outer sheath2110may need to be turned one revolution (360 degrees) or less to fully engage or disengage the threaded connection. In some examples, three-fourths of a turn (270 degrees) or less, one-half of a turn (180 degrees) or less, one-fourth of a turn (90 degrees) or less, or less may be needed to fully engage or disengage the threaded connection.

The inner member120may include at least one stent receiving region126located along a distal region of the inner member120proximal of the distal tip122. A stent200may be disposed over and surround the inner member120in the stent receiving region126, such that the inner member120extends through the stent200and the stent sheath105surrounds the stent200. The stent200may be a self-expanding stent, configured to automatically expand to an expanded state from a constrained state when the stent sheath105is removed from the stent. The stent200may 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 sheath105may hold the self-expanding stent200in its reduced diameter delivery configuration on the stent receiving region126until the stent sheath105is moved to uncover the stent200. In other examples, the stent200may be manually expanded.

The stent200may have one or more markers (not shown) such as radiopaque markers, disposed on the distal end210, proximal end220, or both ends. When markers are present on both the proximal and distal ends220,210of the stent200, the markers may be the same or different. Additionally, alignment markers (not shown) may be disposed on the outer sheath110and/or the inner member120to 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 junction140or the proximal junction145is decoupled (e.g., unscrewed or unthreaded), the stent200may be uncovered by or deployed from the stent sheath105by moving the distal tip122and the outer sheath110longitudinally away from each other. This longitudinal movement may be achieved by either holding the outer sheath110stationary and advancing the inner member120distally and/or holding the inner member120stationary and retracting the outer sheath110proximally.

A stent200may be deployed in a distal-to-proximal direction by decoupling (e.g., unscrewing or unthreading) the distal tip122from the stent sheath105at the distal junction140and then withdrawing the outer sheath110(along with the stent sheath105) proximally, as shown inFIG. 9. Alternatively, the inner member120may be advanced distally, exposing the stent200from the distal end of the stent sheath105. The handle130may be rotated clockwise to rotate the distal tip122clockwise, as indicated by arrow135to decouple (e.g., unscrew or unthread) the distal junction140. Once the distal tip122is separated from the distal end107of the stent sheath105, the outer sheath110and the stent sheath105may be withdrawn proximally while the handle130is held stationary. The handle130may slide along the longitudinal channel111to position130′. As the stent sheath105moves proximally away from the distal tip122, the distal end210of the stent200may be initially uncovered and the stent200may expand in a distal-to-proximal direction. Once the stent200is fully uncovered and fully expanded, the inner member120and distal tip122may be retracted proximally through the expanded stent200, coupled (e.g., screwed or threaded) back onto the stent sheath105, and the device100may be removed from the patient leaving the stent200in place.

The handle130is rotatable relative to the outer sheath110, to provide rotational motion for the inner member120and the distal tip122. The inner member120may be advanced and retracted longitudinally relative to the outer sheath110by moving the handle130along a longitudinal channel111in the outer sheath110and/or handle assembly150. A portion of the handle130extends through the longitudinal channel111and is attached to the inner member120. The length of the longitudinal channel111may be sufficient to allow the handle130to be moved longitudinally to a position where the distal tip122is separated from the distal end107of the stent sheath105by a distance greater than the length of the stent200.

A stent200may be deployed in a proximal-to-distal direction by decoupling (e.g., unscrewing or unthreading) the outer sheath110from the stent sheath105at the proximal junction145and then the inner member120(along with the stent sheath105) may be advanced distally relative to the outer sheath110, as shown inFIG. 10. Alternatively, the outer sheath110may be withdrawn proximally, exposing the stent200from the proximal end of the stent sheath105. The handle130may be rotated counter-clockwise to rotate the stent sheath105counter-clockwise, as indicated by arrow137to decouple (e.g., unscrew or unthread) the proximal junction145. Once the outer sheath110is separated from the proximal end109of the stent sheath105, the inner member120and attached stent sheath105may be moved distally, with the handle130moving along the longitudinal channel111, allowing the outer sheath110to remain stationary. Alternatively, the outer sheath110may be moved proximally. As the stent sheath105moves distally away from the outer sheath110, the proximal end220of the stent200may be initially uncovered and the stent200may expand in a proximal-to-distal direction. Once the stent200is fully uncovered and fully expanded, the inner member120, the distal tip122, and the stent sheath105may be retracted proximally through the expanded stent200, coupled (e.g., screwed or threaded) back onto the outer sheath110, and the device100removed from the patient leaving the stent200in place.

The stent200may be self-expandable or it may be manually expanded with a device such as a balloon (not shown). In some instances, a stent expander160a(shown inFIG. 14) may be provided on the proximal end123of the distal tip122and/or a stent expander160b(shown inFIG. 12) may be provided on the distal end112of the outer sheath110.FIG. 11illustrates features of the stent expander160a/160b. The stent expander160a/160bmay include an elongate member attached at one end in a channel or groove166acut in the threaded distal end112of the outer sheath110and/or a channel or groove166bcut in the threaded proximal end123of the distal dip122. A second, free end of the stent expander160a/160bmay include an enlarged tip162a/162bwhich may be used to adjust the position of the stent200upon expansion. A spring164bmay be disposed under the stent expander160bin the groove166b, which biases the stent expander160bin the elevated, radially outward position, as shown inFIG. 13. In other embodiments, the stent expander160bmay be formed of a resilient material, with the stent expander160bbiased to the elevated, radially outward position.FIGS. 12 and 13illustrate the actuation of the stent expander160battached to the distal end112of the outer sheath110. It is noted that the stent expander160aattached to the proximal end123of the distal tip122may be configured similarly. When the stent sheath105is disposed over the stent200, as shown inFIG. 12, the stent sheath105presses the stent expander160bdown into the groove166b, compressing the spring164bso the stent expander160bdoes not interfere with the threaded connection between the stent sheath105and the distal end112of the outer sheath110. When the stent sheath105is advanced distally from the stent200, the spring164bexpands, returning the stent expander160bto its biased elevated position and the tip162b, which may contact an inner surface of the proximal end region of the stent200and exerts a radially outwardly directed force on the stent200, aids the stent200in expanding in a proximal-first direction, as shown inFIG. 13. In other instances, the resiliency of the stent expander160bmay cause the stent expander160bto revert back towards the elevated positioned once unconstrained by the stent sheath105. The stent expander160bmay aid in expanding the stent200, whether the stent200is self-expanding or manually expanded. Further, the tip162bof the stent expander160bmay be used to move the fully expanded stent200if adjustment to the final position of the stent200is desired. In some instances, the tip162bof the stent expander160bmay contact an inner surface of the stent200as the stent sheath105is moved longitudinally relative to the stent200to facilitate deployment of the stent200from the stent sheath105.

Once the stent200is fully expanded, the stent expander160bmust be returned to the collapsed position within the groove166b. For the stent expander160battached to the distal end112of the outer sheath110, this may be accomplished by moving an outer sheath slider170distally over the stent expander160b(e.g., along a radially outward surface of the stent expander160b), which may push the stent expander160bradially inward down into the groove166b. InFIG. 13, the outer sheath slider170is in the retracted position, with the distal end of the outer sheath slider170just proximal of the stent expander160b. A handle174or other actuator that extends through the outer sheath110may be connected to the proximal end of the outer sheath slider170, and configured to be advanced distally to move the outer sheath slider170distally along the stent expander160b. The outer sheath slider170may be a substantially flat, thin element sufficiently rigid to force the stent expander160bdown into the groove166b. The outer sheath slider170may move within a lumen in the outer sheath110. A channel176through the wall of the outer sheath110and/or the handle assembly150wall may allow the handle174to move back and forth longitudinally to actuate the outer sheath slider170.

FIG. 14shows the stent expander160aattached to the proximal end123of the distal tip122. The inner member120is shown extended distally away from the stent sheath105. The stent200has been removed for clarity. As on the distal end112of the outer sheath110, the stent expander160amay be attached at one end in a channel or groove166acut in the threaded proximal end123of the distal tip122with a spring164aunder the stent expander160a. The spring164amay bias the stent expander160ain an elevated, radially outward position, as shown inFIG. 14. In other embodiments, the stent expander160amay be formed of a resilient material, with the stent expander160abiased to the elevated, radially outward position. An enlarged tip162amay be attached to or otherwise provided at the free end of the stent expander160a. As shown in the enlarged cross-sectional view of the distal tip122inFIG. 14, an inner member slider180is disposed within the distal tip122. The inner member slider180may be attached to a slider extension182that is disposed within a second lumen125in the inner member120, adjacent the guidewire lumen124. Alternatively, the slider extension182may be disposed within the guidewire lumen124. The proximal end of the slider extension182may be attached to a handle184(shown inFIG. 15) or other actuator that extends through a channel186in the outer sheath110and/or the handle assembly150. When the handle184is in the distal most position, the inner member slider180is distal of the stent expander160a, as shown inFIG. 14, and the stent expander160ais in the elevated position. When the handle184is moved proximally, the inner member slider180may be moved proximally over the stent expander160a(e.g., along a radially outward surface of the stent expander160a), pushing the stent expander160adown into the groove166a. As with the outer sheath slider170on the outer sheath110, the inner member slider180and slider extension182on the distal tip122may be a substantially flat, thin element sufficiently rigid to force the stent expander160adown into the groove166aon the proximal end123of the distal tip122.

During distal-first expansion of the stent200, as shown inFIG. 9, when the stent sheath105is withdrawn proximally from the stent200, the spring164aexpands, returning the stent expander160ato its biased elevated position and the tip162a, which may contact an inner surface of the distal end region of the stent200and exerts a radially outwardly directed force on the stent200, aids the stent200in expanding in a distal-first direction. In other instances, the resiliency of the stent expander160amay cause the stent expander160ato revert back towards the elevated positioned once unconstrained by the stent sheath105. The stent expander160amay aid in expanding the stent200, whether the stent200is self-expanding or manually expanded. Further, the tip162aof the stent expander160amay be used to move the fully expanded stent200if adjustment to the final position of the stent200is desired.

As shown inFIG. 9, the handle174connected to the outer sheath slider170is positioned near the distal end of the channel176, indicating the outer sheath slider170is positioned distally over the stent expander160band pressing the stent expander160binto the groove166b, thereby allowing the stent sheath105to slide off the proximal end of the stent200. The handle184connected to the inner member slider180is also positioned near the distal end of the channel186, indicating the inner member slider180is withdrawn distally of the stent expander160a, allowing the stent expander160ato be in the elevated position, as shown inFIG. 14. The stent expander160ais thus in position to aid the stent200in expanding in a distal-to-proximal direction. Once the stent200is fully expanded, the handle184may be moved proximally along the channel186, moving the inner member slider180proximally over and pressing the stent expander160ainto the groove166a. With the stent expander160ain the compressed position, the distal tip122may be withdrawn proximally through the expanded stent200. The distal tip122may then be coupled (e.g., screwed or threaded) back onto the distal end of the stent sheath105and the entire device may be withdrawn.

During proximal-to-distal expansion of the stent200, as shown inFIG. 10, when the distal tip122and attached stent sheath105are advanced distally from the outer sheath110, the spring164bmay expand, returning the stent expander160bto its biased elevated position and the tip162b, which may contact an inner surface of the proximal end region of the stent200and exerts a radially outwardly directed force on the stent200, aids the stent200in expanding in a proximal-first direction. In other instances, the resiliency of the stent expander160bmay cause the stent expander160bto revert back towards the elevated positioned once unconstrained by the stent sheath105. The stent expander160bmay aid in expanding the stent200, whether the stent200is self-expanding or manually expanded. Further, the tip162bof the stent expander160bmay be used to move the fully expanded stent200if adjustment to the final position of the stent200is desired.

As shown inFIG. 10, the handle174connected to the outer sheath slider170is positioned near the proximal end of the channel176, indicating the outer sheath slider170is withdrawn proximally of the stent expander160b, allowing the stent expander160bto be in the elevated position, as shown inFIG. 13. The stent expander160bis thus in position to aid the stent200in expanding in a proximal-to-distal direction. The handle184connected to the inner member slider180is also positioned near the proximal end of the channel186, indicating the inner member slider180is positioned proximally over the stent expander160aand pressing the stent expander160ainto the groove166a, thereby allowing the stent sheath105to slide off the distal end of the stent200.

Once the stent200is fully expanded, the handle174may be moved distally along the channel176, moving the outer sheath slider170distally over and pressing the stent expander160binto the groove166b. With the stent expander160bin the compressed position, the distal tip122and attached stent sheath105may be withdrawn proximally through the expanded stent200. The distal tip122may then be coupled (e.g., screwed or threaded) back onto the distal end of the stent sheath105and the entire device may be withdrawn.

FIG. 15is a top view of the outer sheath110and inner member120, but with the stent sheath105and stent200removed for clarity. Both the outer sheath slider170and inner member slider180are extended over their respective stent expanders160b/160a, forcing the stent expanders160b/160ainto their respective grooves166b/166a. This is indicated by the position of handles174and184. Handle174, connected to the outer sheath slider170, is positioned near the distal end of the channel176, indicating the outer sheath slider170is extended distally over the stent expander160bon the distal end112of the outer sheath110. Handle184, connected to the inner member slider extension182, is near the proximal end of the channel186, indicating the inner member slider180is extended proximally over the stent expander160aon the proximal end123of the distal tip122. The device, with a stent200loaded therein, may be advanced to a target location in a patient in such a configuration. In other instances, the device, with a stent200loaded therein, may be advanced to a target location in a patient, with the handles in the opposite positions such that the stent expander160aand the stent expander160bare pressed radially outward against an inner surface of the stent200. When the device is at the desired location, the user decides whether to deploy the stent200in the proximal-to-distal or distal-to-proximal direction, and thereafter actuate either the handle174or the handle184to facilitate deployment of the stent200.

The materials that can be used for the various components of the delivery device100(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 sheath110and inner member120and other components of device100. 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.

In at least some embodiments, portions or all of the delivery device100and/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 device100in 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 device100to achieve the same result.