U.S. patent application number 14/494492 was filed with the patent office on 2015-03-19 for devices and methods for stent advancement.
The applicant listed for this patent is IDev Technologies, Inc.. Invention is credited to Richard Booth, Gary Boseck, Kenneth M. Bueche, Bruce Dannecker, Jeffery Sheldon, Richard Wisdom.
Application Number | 20150081008 14/494492 |
Document ID | / |
Family ID | 39052692 |
Filed Date | 2015-03-19 |
United States Patent
Application |
20150081008 |
Kind Code |
A1 |
Sheldon; Jeffery ; et
al. |
March 19, 2015 |
DEVICES AND METHODS FOR STENT ADVANCEMENT
Abstract
Devices and methods for stent advancement, including methods for
instructing another or others how to advance a stent into an
anatomical structure or into a testing/demonstration synthetic
structure, such as a polymer tube. The advancement may be achieved
by at least two periods of stent engagement that drive a stent
distally from a sheath separated by a period of non-engagement.
Inventors: |
Sheldon; Jeffery; (League
City, TX) ; Booth; Richard; (Friendswood, TX)
; Boseck; Gary; (Boxford, MA) ; Wisdom;
Richard; (Wydepark, MA) ; Bueche; Kenneth M.;
(Friendswood, TX) ; Dannecker; Bruce; (Tyler,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IDev Technologies, Inc. |
Webster |
TX |
US |
|
|
Family ID: |
39052692 |
Appl. No.: |
14/494492 |
Filed: |
September 23, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11876764 |
Oct 22, 2007 |
8876881 |
|
|
14494492 |
|
|
|
|
60862456 |
Oct 22, 2006 |
|
|
|
Current U.S.
Class: |
623/1.12 |
Current CPC
Class: |
A61F 2/915 20130101;
B23K 26/244 20151001; A61F 2/91 20130101; D03D 3/02 20130101; A61F
2002/91591 20130101; A61F 2002/9534 20130101; A61F 2210/0014
20130101; A61F 2/966 20130101; D04C 1/06 20130101; Y10T 29/49849
20150115; A61F 2/06 20130101; A61F 2/90 20130101; A61F 2002/9665
20130101; B23K 26/20 20130101; A61F 2/86 20130101; A61F 2/95
20130101; A61F 2002/061 20130101; A61F 2220/0058 20130101; A61F
2/844 20130101; A61F 2/885 20130101; D10B 2509/00 20130101; D06C
7/00 20130101; B23K 2103/14 20180801; D10B 2509/06 20130101; B23K
2101/32 20180801 |
Class at
Publication: |
623/1.12 |
International
Class: |
A61F 2/966 20060101
A61F002/966 |
Claims
1-93. (canceled)
94. A stent advancement instruction method comprising: instructing
a person on how to use a stent delivery device that includes a
sheath and a stent disposed in the sheath, the instructing
including demonstrating: distally driving the stent out of the
sheath and into a tubular structure by repeatedly engaging the
stent with a stent-engaging element between distal and proximal
ends of the stent, where at least two of the engagements are
separated by a period of non-engagement; and as the stent is
distally driven out of the sheath, varying the axial density of the
stent within the tubular structure by varying the axial position of
the sheath relative to the tubular structure.
95. The stent advancement instruction method of claim 94, wherein
varying the axial density of the stent within the tubular structure
further comprises varying the rate at which the sheath is withdrawn
from the tubular structure.
96. The stent advancement instruction method of claim 95, wherein
varying the rate at which the sheath is withdrawn comprises
reducing the rate that the sheath is withdrawn from the tubular
structure to increase the axial density of the stent.
97. The stent advancement instruction method of claim 95, wherein
varying the rate at which the sheath is withdrawn comprises
increasing the rate that the sheath is withdrawn from the tubular
structure to decrease the axial density of the stent.
98. A stent advancement instruction method comprising: instructing
a person on how to use a stent delivery device that includes a
sheath and a stent disposed in the sheath, the instructing
including demonstrating: distally driving the stent out of the
sheath and into a tubular structure by repeatedly engaging the
stent with a stent-engaging element between distal and proximal
ends of the stent, where at least two of the engagements are
separated by a period of non-engagement; and releasing the proximal
end of the stent from a stent-retention element when the proximal
end of the stent moves out of the sheath.
99. The stent advancement instruction method of claim 98, wherein
the stent-retention element comprises a stent-retention line, and
wherein the instructing further comprises demonstrating: after the
stent is partially-driven out of the sheath, withdrawing the stent
back into the sheath by moving the stent-retention line.
100. The stent advancement instruction method of claim 99, wherein
the stent delivery device further comprises a handle comprising a
Y-adaptor, and wherein the stent retention line extends from
outside a branch of the Y-adapter and through the branch, the
handle, and a portion of the sheath.
101. The stent advancement instruction method of claim 98, wherein
the stent-retention element comprises radially-projecting
prongs.
102. A stent advancement instruction method comprising: instructing
a person on how to use a stent delivery device that includes a
sheath and a stent disposed in the sheath, the instructing
including demonstrating: moving a user-actuatable element from a
first position in a slot of a handle to a second position in the
slot of the handle, the user-actuatable element coupled to a
stent-engaging element, wherein during moving the user-actuatable
element from the first position to the second position, the
stent-engaging element engages the stent between distal and
proximal ends of the stent to distally drive a first portion of the
stent out of the sheath while a second portion of the stent remains
within the sheath; after moving the user-actuatable element from
the first position to the second position, moving the
user-actuatable element from the second position to the first
position, wherein during moving the user-actuatable element from
the second position to the first position, the stent-engaging
element folds inwardly and slides proximally within the stent; and
after moving the user-actuatable element from the second position
to the first position, second moving the user-actuatable element
from the first position to the second position, wherein during
second moving the user-actuatable element from the first position
to the second position, the stent-engaging element engages the
stent between the distal and proximal ends of the stent to drive
the second portion of the stent at least partially out of the
sheath.
103. The stent advancement instruction method of claim 102, wherein
the demonstrating comprises, after second moving the
user-actuatable element from the first position to the second
position, rotating a stopper to increase a traversable length of
the slot of the handle by the user-actuatable element.
104. The stent advancement instruction method of claim 103, wherein
the demonstrating comprises moving the user-actuatable element to a
third position distal to the second position, wherein during moving
the user-actuatable element to the third position, the
stent-engaging element extends out of the sheath.
105. The stent advancement instruction method of claim 104, wherein
moving the user-actuatable element to the third position comprises
releasing the proximal end of the stent from a stent-retention
element.
106. The stent advancement instruction method of claim 102, wherein
moving the user-actuatable element from the first position to the
second position occurs without a mechanized concomitant withdrawal
of the sheath.
107. The stent advancement instruction method of claim 102, wherein
the user-actuatable element is biased toward the second position in
the slot of the handle.
108. The stent advancement instruction method of claim 102, wherein
the stent comprises woven strands.
109. The stent advancement instruction method of claim 108, wherein
the stent-engaging element is configured to engage strand
intersections.
110. The stent advancement instruction method of claim 102, wherein
the stent-engaging element is shaped like a shovel.
Description
CROSS-REFERENCE(S) TO RELATED APPLICATION(S)
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 60/862,456, filed Oct. 22, 2006, the entire
contents of which are expressly incorporated by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates generally to devices and
methods for stent placement, such as in a body vessel or duct or in
a structure used for testing or demonstration (such as a polymer
tube), and to methods of instructing one or more individuals on
stent placement.
[0004] 2. Description of Related Art
[0005] Examples of stent delivery devices are included in U.S. Pat.
Nos. 5,372,600; 5,433,723; 5,707,376; 5,772,668; 5,776,142;
5,968,052; 6,514,261; 6,599,296; 7,052,511; 7,122,050; U.S. Pat.
App. Pub. No. 20030040772; and U.S. Pat. App. Pub. No.
20050021123.
SUMMARY OF THE INVENTION
[0006] Some embodiments of the present devices (which also may be
characterized as stent deployment devices) include an outer sheath;
a stent disposed within the outer sheath, the stent having a distal
end and a proximal end; a stent-engaging element positioned at
least partially within the lumen of the stent; and a
stent-retention element coupled to the proximal end of the stent;
where the device is configured such that: the stent-engaging
element can be operated in a reciprocating manner to engage and
advance the stent distally at least partially out of the outer
sheath; and the stent-retention element will stay in contact with
the stent during proximal movement of the stent-engaging element
provided that the proximal end of the stent is disposed within the
outer sheath.
[0007] Some embodiments of the present devices include an outer
sheath; a stent disposed within the outer sheath, the stent having
a lumen, a distal end and a proximal end; an inner element
positioned at least partially within the lumen of the stent, the
inner element being configured to accept a guidewire; and a
stent-engaging element positioned at least partially within the
lumen of the stent and being capable of moving distally and
proximally while the inner element is stationary; where the device
is configured to distally drive the stent at least partially out of
the outer sheath through at least two periods of engagement of the
stent by the stent-engaging element that are separated by a period
of non-engagement that does not drive the stent distally.
[0008] Some embodiments of the present devices include an outer
sheath; a handle coupled to the outer sheath such that the outer
sheath cannot move relative to the handle, the handle having a
proximal end; a stent disposed within the outer sheath, the stent
having a lumen, a distal end and a proximal end; and a
stent-engaging element positioned at least partially within the
lumen of the stent; where the device is configured such that: a
user can advance the stent distally out of the outer sheath through
at least two periods of engagement of the stent by the
stent-engaging element that drive the stent distally and that are
separated by a period of non-engagement that does not drive the
stent distally; and the user's proximal-most point of contact with
the device that causes each period of engagement is located at or
distal of the proximal end of the handle.
[0009] Some embodiments of the present devices include an outer
sheath; a stent disposed within the outer sheath, the stent having
a distal end and a proximal end; a reciprocating element disposed
at least partially within the outer sheath, the reciprocating
element having a stent-engaging portion (which also may be
characterized as a stent-engaging element); a user-actuatable
element coupled to the reciprocating element; and a stent-retention
element coupled to the proximal end of the stent; wherein: the
stent-engaging portion is operable in a reciprocating manner to
engage and advance the stent distally at least partially out of the
outer sheath; and the stent-retention element stays in contact with
the stent during proximal movement of the stent-engaging portion
provided that the proximal end of the stent is disposed within the
outer sheath.
[0010] Some embodiments of the present devices include an outer
sheath; a stent disposed within the outer sheath, the stent having
a distal end and a proximal end; a device body coupled to the outer
sheath; a reciprocating element disposed at least partially within
the outer sheath, the reciprocating element having a stent-engaging
portion; and a user-actuatable element mounted on the device body
and coupled to the reciprocating element; wherein the device is
configured such that the stent-engaging portion is operable in a
reciprocating manner to engage and advance the stent at least
partially out of the outer sheath, and the outer sheath need not
move relative to the device body in order for the stent-engaging
portion to advance the stent.
[0011] Some embodiments of the present devices include an outer
sheath; a stent disposed within the outer sheath, the stent having
a distal end and a proximal end; a device body coupled to the outer
sheath; a hollow reciprocating element disposed at least partially
within the outer sheath, the hollow reciprocating element having a
stent-engaging portion; a user-actuatable element mounted on the
device body and coupled to the hollow reciprocating element; a
stent-retention element coupled to the proximal end of the stent;
and an inner tube disposed at least partially within the outer
sheath, a portion of the inner tube being at least partially within
the hollow reciprocating element; wherein: the hollow reciprocating
element is operable to move (a) distally in response to a user
moving the user-actuatable element distally and (b) proximally in
response to a user moving the user-actuable element proximally; the
stent-engaging portion is operable in a reciprocating manner to
engage and advance the stent at least partially out of the outer
sheath; the outer sheath need not move relative to the device body
in order for the stent-engaging portion to advance the stent; the
stent-retention element stays in contact with the stent during
proximal movement of the stent-engaging portion provided that the
proximal end of the stent is disposed within the outer sheath; and
the stent-retention element is operable to withdraw the stent
proximally back into the outer sheath provided that a proximal
portion of the stent is disposed within the outer sheath.
[0012] Some embodiments of the present stent advancement methods
include advancing a stent disposed within a sheath disposed within
a body vessel using a multiple reciprocating movements of a
reciprocating element, where: each reciprocating movement includes
a distal movement of the reciprocating element and a proximal
movement of the reciprocating element; the stent is advanced
distally in response to each distal movement of the reciprocating
element; the stent is not advanced in response to each proximal
movement of the reciprocating element; and each distal movement of
the reciprocating element does not coincide with a separate
proximal movement of the sheath.
[0013] Some embodiments of the present stent advancement methods
include distally driving a stent out of a sheath and into a tubular
structure by repeatedly engaging the stent between its distal and
proximal ends with a stent-engaging element, where at least two of
the engagements are separated by a period of non-engagement; and as
the stent is distally driven out of the sheath, varying the axial
density of the stent within the tubular structure by varying the
axial position of the sheath relative to the tubular structure.
[0014] Some embodiments of the present stent advancement
instruction methods include instructing a person on how to use a
stent delivery device that includes a sheath and a stent disposed
in the sheath, the instructing including demonstrating the
following steps to the person: distally driving the stent out of
the sheath and into a tubular structure by repeatedly engaging the
stent between its distal and proximal ends with a stent-engaging
element, where at least two of the engagements are separated by a
period of non-engagement; and as the stent is distally driven out
of the sheath, varying the axial density of the stent within the
tubular structure by varying the axial position of the sheath
relative to the tubular structure.
[0015] Any embodiment of any of the present devices and methods may
consist of or consist essentially of--rather than
comprise/include/contain/have--the described features and/or
steps.
[0016] Details associated with these embodiments and others are
provided below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following drawings illustrate by way of example and not
limitation. They illustrate two different embodiments of the
present delivery devices, the second of which appears in FIGS. 13
and 14. They also illustrate the manner in which stent density can
be altered during delivery (FIGS. 15A-15C), and a schematic of one
of the present demonstration techniques (FIG. 16).
[0018] FIGS. 1, 2A, 2B, 2C, 3A, 3B, 3D, 3E, 4-7, 11, 12A, 13, and
14 are drawn to scale (in terms of proportions), save the length of
line 72, which can be varied as desired. Identical reference
numerals do not necessarily indicate an identical structure.
Rather, the same reference numeral may be used to indicate a
similar feature or a feature with similar functionality. Not every
feature of each embodiment is labeled in every figure in which that
embodiment appears, in order to keep the figures clear.
[0019] FIG. 2D is a cross-sectional view of a sub-assembly of an
embodiment of device.
[0020] FIG. 3C is a cross-sectional view of a sub-assembly of an
embodiment of device.
[0021] FIG. 8 provides a schematic depiction of the stent
advancement process.
[0022] FIG. 9 depicts stent in a constrained, or elongated,
configuration.
[0023] FIG. 10 shows stent in an expanded state in body vessel.
[0024] FIG. 12B shows an embodiment of the stent-retention
element.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0025] The terms "comprise" (and any form of comprise, such as
"comprises" and "comprising"), "have" (and any form of have, such
as "has" and "having"), "contain" (and any form of contain, such as
"contains" and "containing"), and "include" (and any form of
include, such as "includes" and "including") are open-ended linking
verbs. As a result, a device or method that "comprises," "has,"
"contains," or "includes" one or more elements possesses those one
or more elements, but is not limited to possessing only those one
or more elements or steps. Likewise, an element of a device or a
step of a method that "comprises," "has," "contains," or "includes"
one or more features possesses those one or more features, but is
not limited to possessing only those one or more features.
Furthermore, a structure that is configured in a certain way must
be configured in at least that way, but also may be configured in a
way or ways that are not specified.
[0026] Any embodiment of any of the present devices and methods may
consist of or consist essentially of--rather than
comprise/include/contain/have--the described features and/or
steps.
[0027] The terms "a" and "an" are defined as one or more than one
unless this disclosure explicitly requires otherwise. The terms
"substantially" and "about" are defined as at least close to (and
include) a given value or state (preferably within 10% of, more
preferably within 1% of, and most preferably within 0.1% of).
[0028] An illustrative embodiment of the present devices appears in
perspective in FIG. 1. Device 10 includes outer sheath 20 and
device body 90 (which, in this embodiment, is a handle configured
to be held in one hand) coupled to outer sheath 20. In this
embodiment, the outer sheath is coupled to the handle such that the
outer sheath cannot move relative to the handle (that is, the two
are coupled to each other in a fixed relationship). Outer sheath 20
is a hollow member configured such that a stent can be disposed
within it when the stent is in a constrained (e.g, elongated) state
prior to delivery.
[0029] A portion of the embodiment of FIG. 1 near device body 90 is
illustrated in perspective in FIG. 2A and in cross-section in FIG.
3. These figures show that device 10 includes user-actuatable
element 50 that is coupled to (and, in this embodiment, mounted on
so as to be slidable with respect to) device body 90 and also
coupled to element 40, which in this embodiment has a passageway
and is configured to fit within outer sheath 20. In the embodiment
shown in FIGS. 2A and 3A, user-actuatable element 50 is slidably
mounted on device body 90 and coupled to element 40 via block 51.
In some embodiments, block 51 may include a biasing element (such
as a spring) that biases user-actuatable element 50 toward the
position shown in FIG. 3A. In other embodiments, block 51 does not
include a biasing element.
[0030] User-actuatable element 50, block 51, and element 40 of
device 10 are moveable in the proximal and distal directions (which
is along the longitudinal axis (not shown) of the device), and are
generally constrained in other directions. Thus, proximal movement
of user-actuatable element 50 (towards proximal side 92) results in
proximal movement of element 40, and distal movement of
user-actuatable element 50 (towards distal side 91) results in
distal movement of element 40. In the depicted embodiment, the
distance that user-actuatable element 50 moves (either proximally
or distally) will translate into movement of element 40 by the same
distance. This translation could be geared up or down as desired.
As explained in greater detail below, element 40 is coupled to
stent-engaging element 45, which engages and drives the loaded
stent distally from the outer sheath during at least a portion of
the time the stent-engaging element is moved distally within the
lumen of the stent.
[0031] FIG. 2A also shows that device 10 may include an element 25
that is coupled (slidably) to the outside of outer sheath 20.
Element 25 can be configured to slide relatively freely along the
outer surface of the outer sheath, and it can be configured to
interface with a hemostasis valve of an introducer (see FIG. 3B).
Specifically, in can be configured to fit partially inside the
introducer and interface with the hemostasis valve such that fluid
does not flow back toward the handle of the device yet the outer
sheath of the device can slide relatively freely within element 20
and the introducer. Effectively, element 25 can act to reduce the
friction between the outer sheath of the device and an introducer
through which the outer sheath of the device is inserted, while
maintaining a substantial fluid seal between the outer sheath and
the exterior of the patient.
[0032] Referring to FIGS. 1, 4 and 5, outer sheath 20 extends
distally from device body 90. Device 10 also includes inner element
60, a portion of which is located within outer sheath 20. Inner
element 60 (and, more specifically in the preferred embodiment,
inner sleeve 61 as shown in FIG. 2D, described below) is coupled at
its distal end to nose cone 150. Inner element 60, which is not
constrained axially by sheath 20 (in that the two have sufficiently
different diameters that they do not touch), facilitates motion of
nose cone 150 relative to outer sheath 20 and it is sized such that
a guidewire may be passed through it (as is nose cone 150).
Radiopaque marker 27 may be placed at any suitable location along
outer sheath 20 in order to provide a means for aiding deployment
of a stent. For example, the distance from the distal end of outer
sheath 20 and marker 27 may be the nominal length of the stent
being delivered in its deployed state. FIG. 5 illustrates distal
end 31 of stent 30 within outer sheath 20. In some embodiments,
neither element 40 nor stent-engaging element 45 is attached to
inner element 60. As a result, element 40 may be moved proximally
and over inner element 60 while inner element 60 is stationary.
Similarly, stent-engaging element 45 may be moved proximally and
distally over inner element 60 while inner element 60 is
stationary.
[0033] Returning to FIGS. 2A and 3A and referring also to FIG. 2C,
the allowable proximal-distal travel of user-actuatable element 50
is constrained by the length of slot 52 in device body 90, as well
the position of stopper 120. First position 121 of stopper 120
shown in FIG. 2A limits the distal travel of user-actuatable
element 50 to less than the full length of slot 52. Preferably,
first position 121 corresponds to a distal-most position of
user-actuatable element 50 where the stent-engaging element 45
remains within outer sheath 20. This corresponds to the proper
configuration for advancement of stent 30.
[0034] Stopper 120 is preferably biased to first position 121 with,
e.g, a spring. In FIGS. 2C and 3A, stopper 120 has been rotated to
a second position 122 (labeled as such in FIG. 2C) that allows
user-actuatable element 50 to slide past it, as shown.
[0035] FIG. 2D is a cross-sectional view of a sub-assembly of a
preferred embodiment of device 10, which sub-assembly includes a
preferred embodiment of inner element 60 in the form of an inner
sleeve 61 that extends the length of inner element 60 and that is
configured to accept a guidewire. Inner element 60 may also include
intermediate sleeve 62 that may be secured at its distal end (or
any other suitable location) to inner sleeve 61 in any suitable
fashion, such as Loctite.RTM. 4014 adhesive. Intermediate sleeve 62
(which may be a hypotube) also may extend to the proximal end of
inner element 60. Inner element 60 may also include outer sleeve 63
(which may be a hypotube) connected at its distal end (or any other
suitable location) to intermediate sleeve 62 in any suitable
manner, such as through soldering; outer sleeve 63 also may extend
to the proximal end of inner element 60. Inner element 60 may also
include a travel-limiting sleeve 64 connected at its distal end (or
any other suitable location) to outer sleeve 63 in any suitable
manner, such as through soldering. Sleeve 64 may be configured to
restrict the travel of inner element 60 with respect to device body
90. More specifically, sleeve 64 can be configured to interfere
(due to its size) with the proximal opening (not labeled) of cavity
55 of device body 90 (see FIG. 3A), and it can be configured to
interfere distally with block 51 (if Luer fitting 100 does not
first interfere with Y-adapter 95).
[0036] FIG. 3B is an enlarged, cross-sectional view, showing the
interaction between element 25 and introducer 35, where element 25
is interfacing with seal 31 of the hemostasis valve of introducer
35.
[0037] FIG. 3C is a cross-sectional view of a sub-assembly of a
preferred embodiment of device 10, which sub-assembly includes a
preferred embodiment of element 40 in the form of proximal hypotube
41 secured in any suitable fashion to block 51, such as by a press
fit that terminates at shoulder 57 or with a suitable adhesive,
such as one of the Loctite.RTM. adhesives (e.g., 4014, 4305, 3321,
etc.). Block 51 is secured to user-actuatable element 50 through
pin 54, which can be bonded to element 50 and press fit or bonded
to block 51. Element 40 may also include an intermediate tube 42
that is connected at its proximal end to proximal hypotube 41 in
any suitable manner, such as through Loctite.RTM. 4305, and at its
distal end to support tube 46 (that is in turn connected to
stent-engaging element 45 in any suitable fashion, such as an
adhesive) in any suitable manner, such as through an adhesive.
Element 40 may also include a support tube 43 that is positioned
over intermediate tube 42 and that abuts the distal end of proximal
hypotube 41. Support tube 43 may be connected at any suitable
location to intermediate tube 42 using any suitable adhesive. The
support tube may be configured to increase the rigidity of
intermediate tube 42. Element 40 may also include resheathing stop
44 that is threaded over intermediate tube 42 and that abuts the
distal end of support tube 43. Resheathing stop 44 may be connected
at any suitable location to intermediate tube 42 using any suitable
adhesive. Resheathing stop 44 may be configured to prevent proximal
movement of the stent that is enclosed by outer sheath 20 (not
shown in this figure) should the stent be re-sheathed during the
delivery process. The depicted sub-assembly also includes a
silicone seal 56 that is designed to prevent the backflow of fluid
around the outside of inner element 60 (and, more specifically, an
outer hypotube that is part of a preferred embodiment of inner
element 60) and that is held in place by a stainless steel retainer
58.
[0038] Referring to FIG. 6, element 40 extends such that a portion
of it is located within outer sheath 20. Preferably, element 40 is
hollow and its passageway accommodates a portion of inner tube 60
being located within it. Alternate embodiments of this element may
be non-hollow.
[0039] Referring to FIGS. 6-7, element 40 is coupled to a
stent-engaging element 45, which, in this embodiment, is shaped
like a shovel or scoop. More specifically, in the depicted
preferred embodiment, intermediate tube 42 of element 40 is
connected to support tube 46, which is connected to stent-engaging
element 45. Stent-engaging element 45 is positioned at least
partially within the lumen of stent 30. As element 40 moves
distally in response to distal movement of user-actuatable element
50, stent-engaging element 45 engages stent 30, advancing it along
outer sheath 20. In a preferred embodiment, proximal motion of
stent-engaging portion 45 results in no motion of stent 30.
Repeated reciprocating distal and proximal motion of element 40 in
this manner results in advancement of stent 30 until it exits outer
sheath 20. Thus, those of ordinary skill in the art will understand
that the illustrated embodiment of device 10 is configured such
that a user can advance stent 30 distally out of outer sheath 20
through multiple engagements of the stent by stent-engaging element
45, where each engagement: occurs between the proximal and distal
ends of stent 30, drives stent 30 distally without a mechanized
concomittant withdrawal of outer sheath 20, and is separated from
any subsequent engagement by a period of not driving stent 30
distally; and the user's proximal-most point of contact with device
10 that causes each engagement (which occurs at user-actuatable
element 50) is located at or distal of the proximal end of device
body 90. Stent-engaging element 45 may include a flex slot 48
provided with rounded, dumbbell-shaped ends that help alleviate
fatigue stress fractures and the like and that allow element 45 to
fold inwardly as it slides proximally within the lumen of stent 30.
Preferably, the performance of stent-engaging portion 45 is
achieved by appropriate shape selection, as depicted in FIG. 7.
Alternate embodiments may employ stent-engaging portions that flex,
are hinged, or otherwise change shape to achieve stent advancement.
The configuration of the stent-engaging portion may be chosen to
best suit the type of stent to be deployed. When stent 30 is a
woven, self-expanding stent, such as the kind disclosed in U.S.
Pat. No. 7,018,401, which is incorporated by reference,
stent-engaging element 45 is preferably configured (as shown in the
figures) so as to (a) engage wire intersections on opposing sides
of stent 30 when driving the stent distally, and (b) fold inwardly
(due, at least in part, to flex slot 48 of the stent-engaging
element) and slide proximally within the stent's lumen.
[0040] FIG. 8 provides a schematic depiction of the stent
advancement process. Distal end 31 of stent 30 has exited outer
sheath 20 and has expanded. Element 40 moves proximally and
distally, as indicated by arrows. As stent-engaging element 45
travels distally, it engages and advances stent 30, thus driving it
out of outer sheath 20. No advancement of stent 30 occurs when
stent-engaging element 45 travels proximally due to the shape of
stent-engaging element 45. Instead, the configuration of
stent-engaging element 45 enables it to bend inwardly as it moves
over and encounters portions (e.g., wire portions) of stent 30
during the proximal movement of user-actuatable element 50 without
disturbing the axial position of the stent relative to the outer
sheath. Preferably, advancement of stent 30 is achieved without a
mechanized concomittant withdrawal of outer sheath 20 and without
motion of outer sheath 20 relative to device body 90 (aside from
incidental motion caused by patient's body movements, vibrations,
etc.).
[0041] FIGS. 9-10 illustrate schematically stent deployment in a
body vessel. FIG. 9 depicts stent 30 in a constrained, or
elongated, configuration. This is an example of a configuration of
stent 30 when it is within outer sheath 20 of device 10. FIG. 10
shows stent 30 in an expanded state in body vessel 160, which is
one state a self-expanding stent may take when it exits outer
sheath 20.
[0042] In some embodiments, the present devices may also include a
stent-retention element configured to allow an operator to
re-sheath the stent during the advancement and/or deployment
process, provided the stent has not been advanced completely out of
the sheath. Referring to FIGS. 11 and 12A, device 10 includes
stent-retention element 70 coupled to proximal end 32 of stent 30.
In a preferred embodiment, contact between distal portion 71 of
stent-retention element 70 and stent 30 exists as long as proximal
end 32 of stent 30 is within outer sheath 20, even during proximal
movement of stent-engaging element 45. When proximal end 32 of
stent 30 is advanced outside of outer sheath 20, stent 30 expands
to a radius larger than the greatest width (taken in the radial
direction shown in the figures) of distal portion 71 of
stent-retention element 70. As a result, contact between stent 30
and stent-retention element 70 ceases, and deployment of stent 30
is completed. Accordingly, stent-retention element 70 is operable
to withdraw stent 30 proximally back into outer sheath 20 (through
action by an operator) provided that a proximal portion of stent 30
(specifically, the proximal portion coupled to stent-retention
element 70) is disposed within outer sheath 20.
[0043] Referring to FIGS. 2A, 3A and 11-12, proximal portion 72
(also visible in FIG. 3B) of stent-retention element 70 is a cable
or similar device that facilitates withdrawal of stent 30
proximally back into outer sheath 20 and that may be characterized
as a stent-retention line, provided that a proximal portion of
stent 30 is disposed within outer sheath 20. Distal portion 71 of
stent-retention element 70 may be a piece of tubing (such as
hypotube) that is provided with multiple, radially-projecting
prongs 73 that engage openings in woven versions of stent 30. The
tubing may be coupled in any suitable fashion (such as through
soldering) to proximal portion 72.
[0044] As shown in FIGS. 1 and 2A, Y-adapter 95 may be coupled to
the proximal portion of device body 90. Inner tube 60 may be placed
through straight arm 96 and proximal portion 72 may be placed
through angled arm 97 of Y-adapter 95. As shown in FIG. 2B, a
stent-retention element position marker 93 may be coupled to line
72 and positioned along the line to the relative position of the
stent that is coupled to the stent-retention element. For example,
the marker, which may be a piece of heat shrink tubing, may be
positioned along the line such that when it extends into the
perimeter of angled arm 97 the stent will completely exit outer
sheath 20. In this way, an operator has a visual indicator that
conveys how far the stent has exited the outer sheath. FIGS. 1 and
2A also show that the stent-retention element may include a finger
element 98 coupled to line 72 in any suitable manner (e.g., though
LOCTITE.RTM. adhesive), to provide a user with something to hold to
enable manipulation of the stent-retention element. FIG. 12B shows
a preferred embodiment of stent-retention element 70, which finger
element 98 in cross-section and showing an example connection
location 99 (for adhesive or the like) between line 72 and finger
element 98 (which may have inner and outer components, as shown,
that are threaded together).
[0045] Preferably, device 10 comprises side port 110 (coupled to
device body 90) and Luer fitting 100 (coupled to proximal end 62 of
inner tube 60) to allow for flushing of outer sheath 20 and inner
tube 60, respectively. The flushing may be with saline and may
occur prior to a procedure. Alternate embodiments of the present
devices may include alternate designs for flushing outer sheath 20
and inner tube 60, or may not be configured to allow for flushing.
FIG. 3D is a top view of device 10 and identifies a cutaway detail
near the distal end of device body 90 that is shown in greater
detail in FIG. 3E.
[0046] Referring to FIG. 2C, second position 122 of stopper 120
allows user-actuatable element 50 to travel distally the full
length of slot 52. The distal-most position of user-actuatable
element 50 corresponds to a position where stent-engaging element
45 is outside (distal to) outer sheath 20, and therefore in a
region where stent 30 will be driven out of outer sheath 20 and in
its expanded state. A stent in this position that is de-coupled
from distal portion 71 of stent-retention element 70 can no longer
be withdrawn into outer sheath 20. Furthermore, a stent in an
expanded condition will have radial clearance over stent-engaging
element 45. Alternate embodiments of the present devices may employ
other designs to limit the travel of user-actuatable element 50, or
have no adjustable travel-limiting feature.
[0047] FIGS. 13-14 depict another embodiment of the present devices
that includes capture device 80 coupled to proximal portion 72 of
stent-retention element 70. Capture device 80 serves to release
appropriate amounts of proximal portion 72 as stent-engaging
element 45 advances stent 30. Capture device 80 includes a stop
that serves to halt distal advancement of stent 30 prior to full
deployment of stent 30 from outer sheath 20. The stop (which can be
a piece of tubing, such as hypotube, that is coupled at an
appropriate location to proximal portion 72) provides operator
feedback at the point where further advancement would result in
stent deployment (thus, the stop can be used as an indicator of the
location at which stent withdrawal will no longer be possible).
Here, the operator may choose to withdraw stent 30 into outer
sheath 20 for repositioning by pulling proximally on
stent-retention element 70, or proceed with stent deployment by
depressing deployment stop lever 81 (which allows the stop to
bypass the deployment stop lever and permits continued distal
advancement of the stent-retention element) and continuing with
advancement via user-actuatable element 50.
[0048] If the operator chooses to withdraw stent 30 into outer
sheath 20 for repositioning, the operator can actuate retention
pull lever 84, which (in the depicted embodiment) de-couples
capture device 80 from device body 90 and allows the operator to
proceed with withdrawing stent 30 by pulling proximal portion 72 of
stent-retention element 70 proximally. After withdrawal of stent 30
into outer sheath 20, retention pulley 82 and spring 83 of capture
device 80 operate to accumulate excess slack of stent-retention
element 70. In this embodiment, proximal portion 72 of
stent-retention element 70 may be threaded through a portion of
device body 90 that is not centrally disposed within the device
body. Alternate embodiments of the present devices that include
capture devices may include capture devices that are configured
differently from capture device 80, such as automated capture
devices. Furthermore, capture device 80 may be coupled to angled
arm 97 in the embodiment of device 10 shown in FIG. 1, in place of
finger element 98.
[0049] The present devices may be disposable and packaged in a bag,
pouch, box, or other suitable container, after having been
sterilized using any suitable technique, such as sterilization
using ethylene oxide gas. There may be a small gap between the
distal end of the outer sheath and the proximal end of the nose
cone to allow for the sterilizing gas to flow throughout the
device. The container may include instructions for using the device
that are printed on the container or included inside the container.
After the device is removed from its container, saline may be used
to flush the outer sheath and its contents and the inner tube. The
gap between the nose cone and the outer sheath can then be closed
by pulling proximally on the inner tube to which the nose cone is
coupled. If the procedure involves stenting a blood vessel, any
suitable technique for positioning the device in the appropriate
location may be used (e.g, such as the Seldinger technique). The
nose cone of the device (which may be any suitable flexible tip)
may be radio opaque and may represent a distal-most marker for the
device. Another radio opaque marker made from any suitable material
(such as a platinum band, or a band made from any suitable platinum
alloy) may be coupled to a portion of the device that is proximal
to the nose cone, such as to the outer sheath (as discussed above),
element 40, or the inner element, to create a proximal-most marker
for the device. These two markers may be used by the operator to
position the device relative to the lesion of interest to enable
accurate deployment of the stent.
[0050] The present methods include stent advancement methods for
distally driving a stent out of a sheath (e.g., outer sheath 20)
and into a tubular structure. In some embodiments, the tubular
structure is animal tissue (such as a human blood vessel). In other
embodiments, the tubular structure is not animal tissue and
comprises a polymer structure that can be used to test a given
device technique or demonstrate stent advancement to one or more
persons, such as a doctor considering using the device or stent
advancement technique in his or her practice.
[0051] Some embodiments of the present stent advancement methods
include distally driving a stent (e.g., stent 30) out of a sheath
(e.g., outer sheath 20) and into a tubular structure by repeatedly
engaging the stent between its distal and proximal ends with a
stent-engaging element (e.g., stent-engaging element 45), where at
least two of the engagements are separated by a period of
non-engagement; and as the stent is distally driven out of the
sheath, varying the axial density of the stent within the tubular
structure by varying the axial position of the sheath relative to
the tubular structure. As the stent is driven distally out of the
sheath, the remainder of the device is withdrawn proximally by the
operator relative to the tubular structure so that the deployed
portion of the stent remains stationary relative to the tubular
structure (e.g., human tissue) into which it is deployed. The rate
at which the remainder of the device is withdrawn may be varied to
vary the axial density of the stent: a slower withdrawal rate
increases the axial density of the stent, whereas a faster rate
decreases the axial density of the stent. It may be desirable to
increase the axial density of the stent in, for example, a location
where a greater hoop strength is required to maintain the patency
of the tubular structure, such as along a stenosed region 210 of an
artery 200 as shown in FIG. 15A. It may be desirable to decrease
the axial density of the stent in, for example, a location where
fluid flow into a section of the stent from the side is anticipated
or desired, or at the location of penetration of a second stent,
either of which may be true at an anatomical side branch 260 of a
vessel 250 as shown in FIG. 15B.
[0052] Some embodiments of the present stent advancement methods
include distally driving a stent (e.g., stent 30) out of a sheath
(e.g., outer sheath 20) and into a tubular structure by repeatedly
engaging the stent between its distal and proximal ends with a
stent-engaging element (e.g., stent-engaging element 45), where at
least two of the engagements are separated by a period of
non-engagement; and engaging the stent at its proximal end with a
stent-retention element (e.g., stent-retention element 70) that is
positioned within the sheath.
[0053] In some embodiments, the engagements that drive the stent
distally from the sheath may be achieved using a device that is
configured to not mechanically concomittantly withdraw the sheath
as the stent is driven distally, such as the versions of the
present devices shown in the figures. The tubular structure in
those embodiments can be an anatomical tubular structure, such as a
vessel or duct, or a tubular structure that is not animal tissue,
such as a polymer tube 300 (see FIG. 15C). Regardless, in some
embodiments, the method may also include engaging the stent at its
proximal end with a stent-retention element that is positioned
within the sheath. The stent-retention element may include a
stent-retention line, and the method may also include, after the
stent is partially-driven out of the sheath, withdrawing the stent
back into the sheath by moving the stent-retention line. An
operator may accomplish the driving of the stent by moving a
user-actuatable element (e.g., user-actuatable element 50) with the
operator's thumb. The stent may be woven, a stent-engaging element
may engage multiple wire intersections of the stent and move
distally during the engagements that drive the stent, and the
stent-engaging element may slide proximally within the stent's
lumen during the period of non-engagement.
[0054] Some of the present methods are methods of instructing
another or others on how to advance a stent out of sheath and into
a tubular structure. Some embodiments of the present stent
advancement instruction methods include instructing a person on how
to use a stent delivery device (e.g., device 10) that includes a
sheath (e.g., outer sheath 20) and a stent (e.g., stent 30)
disposed in the sheath. The instructing may include demonstrating
the following steps to the person: distally driving the stent out
of the sheath and into a tubular structure by repeatedly engaging
the stent between its distal and proximal ends with a
stent-engaging element (e.g., stent-engaging element 45), where at
least two of the engagements are separated by a period of
non-engagement; and, as the stent is distally driven out of the
sheath, varying the axial density of the stent within the tubular
structure by varying the axial position of the sheath relative to
the tubular structure.
[0055] Some embodiments of the present stent advancement
instruction methods include instructing a person on how to use a
stent delivery device (e.g., device 10) that includes a sheath
(e.g., outer sheath 20) and a stent (e.g., stent 30) disposed in
the sheath. The instructing may include demonstrating the following
steps to the person: distally driving the stent out of the sheath
and into a tubular structure by repeatedly engaging the stent
between its distal and proximal ends with a stent-engaging element
(e.g., stent-engaging element 45), where at least two of the
engagements are separated by a period of non-engagement; and
engaging the stent at its proximal end with a stent-retention
element (e.g., stent-retention element 70) that is positioned
within the sheath.
[0056] The instruction methods may be accomplished in some
embodiments by a live demonstration in the presence of the person
and in other embodiments by a recorded or simulated demonstration
that is played for the person. An example of a recorded
demonstration is one that was carried out by a person and captured
on camera. An example of a simulated demonstration is one that did
not actually occur, and that instead was generated using a computer
system and a graphics program. In the case of a recorded or
simulated demonstration, the demonstration may exist in any
suitable form--such as a on DVD or in any suitable video file (such
as an .mpg, .mov., .qt, .rm, .swf, or .wmv file)--and the
instructing may be accomplished by playing the demonstration for
the viewer using any suitable computer system. The viewer or
viewers may cause the demonstration to play. For example, the
viewer may access the recorded or simulated demonstration file
using the internet, or any suitable computer system that provides
the viewer with access to the file. See FIG. 16.
[0057] In embodiments of the present methods that involve stent
delivery into an anatomical structure, and the device used to
accomplish the method is in a desired location within a patient to
start the stent advancement, the movement (e.g, the ratcheting
movement) of the stent-engagement element can begin such that the
distal end of the stent (which can also be provided with one or
more radio opaque markers to enable easier viewing of its position
during the procedure) exits the outer sheath of the device, but not
to such an extent that it expands to contact the anatomical
structure. If the distal end of the stent is proximal of where the
operator wants it, and a stent-retention element is used, the
stent-retention element can be pulled proximally to resheath the
stent and reposition the device; if the stent is distal of where
the operator wants it, the entire device can be withdrawn
proximally and the deployment process continued.
[0058] The different features of the present devices can be made
from commercially-available, medical-grade materials. For example,
nose cone 150 may be made from a polyether block amide (such as
PEBAX.RTM. resin, available from Arkema Inc, Philadelphia, Pa.). A
distal portion of inner element 60 (such as inner sleeve 61) may be
made from polyimide and coupled to a more proximal portion made
from stainless steel hypotube (such as 304 or 316L stainless
steel). Luer fitting 100 coupled to inner element 60 (e.g., outer
sleeve 63) may be made from polycarbonate. Outer sheath 20 may be
made from a braided polyether block amide (e.g, a braided
PEBAX.RTM. resin). Device body 90, user-actuatable element 50,
block 51, and stopper 120 may be made from ABS (acrylonitrile
butadiene styrene) plastic, polycarbonate, or DELRIN.RTM. acetal
resin (available from DuPont). Stopper 120 may be coupled to a
stainless steel spring that biases it as described above. Element
40 may have a shaft formed from polyimide (or, a series of shafts,
as in the preferred embodiment, that are made from polyimide or
nitinol hypotube), and stent-engaging element 45 may include or be
coupled to a short piece of nitinol hypotube (e.g., tube 46)
coupled to the polyimide shaft with a suitable adhesive (e.g,
LOCTITE.RTM. adhesive, which includes cyanoacrylates) and a piece
of nitinol hypotube fashioned in the desired shape and welded (e.g,
laser welded) to the short piece of nitinol hypotube.
Stent-retention element 70 may include an intertwined stainless
steel wire (used as proximal portion 72) that is covered with a
material such as nylon, FEP (fluorinated ethylene propylene)
tubing, or PET (polyester) tubing, and distal portion 71 may be
made from stainless steel hypotube. Furthermore, steps may be taken
to reduce the friction between the parts that contact or may
contact either other during use of the present devices, such as
contact between the stent and the outer sheath.
[0059] The present devices may be used to deliver self-expending
stents that are woven, including stents woven from multiple
strands, such as wires. Some examples of weaving techniques that
may be used include those in U.S. Pat. Nos. 6,792,979 and
7,048,014, which are incorporated by reference. The strands of a
woven stent may terminate in strand ends (e.g, wire ends) that are
then joined together using small segments of material, such as
nitinol hypotube, when the stent strands are wires made from
nitinol. The stent may be passivated through any suitable technique
in order to remove the oxide layer from the stent surface that can
be formed during any heat treating and annealing, thus improving
the surface finish and corrosion resistance of the stent material.
Suitable stent creation techniques for stents that may be used with
the present devices (including the strand crossings that may be
engaged by stent-engaging element 45) are set forth in U.S. patent
application Ser. No. 11/876,666, which is incorporated by
reference.
[0060] It should be understood that the present devices and methods
are not intended to be limited to the particular forms disclosed.
Rather, they are to cover all modifications, equivalents, and
alternatives falling within the scope of the claims. For example,
while the embodiments of the present devices shown in the figures
included a stent-engaging element and a user-actuatable element
that moved the same distances in response to operator input, other
embodiments of the present devices could include gears or other
mechanisms that create a ratio between the distance that the
user-actuatable element moves and the resulting distance that the
stent-engaging element moves that is not 1:1 (such that the
reciprocating element distance can be greater or less than the
user-actuatable element distance). Furthermore, still other
embodiments may employ other structures for achieving periodic
engagement of a stent in order to advance it distally, such as a
through a squeeze-trigger mechanism similar to the one shown in
U.S. Pat. No. 5,968,052, which is incorporated by reference, or in
U.S. Pat. No. 6,514,261, which is incorporated by reference, or
through a stent-engaging element that rotates rather than
translates and that possesses a cam portion configured to engage
the stent during part of a given rotation and not engage the stent
during another part of that rotation. Furthermore, still other
embodiments may employ other forms of reciprocating movement of a
stent-engaging element (such as stent-engaging element 45), such as
through another form of operator input like a rotational
user-actuatable input (rather than a translation input, as is shown
in the figures) coupled to the stent-engaging element via a
cam.
[0061] The claims are not to be interpreted as including
means-plus- or step-plus-function limitations, unless such a
limitation is explicitly recited in a given claim using the
phrase(s) "means for" or "step for," respectively.
* * * * *