U.S. patent application number 12/684569 was filed with the patent office on 2010-07-15 for rapidly eroding anchor.
This patent application is currently assigned to ABBOTT VASCULAR INC.. Invention is credited to Kelly J. McCrystle, Karim S. Osman, Wouter E. Roorda, Laveille K. Voss.
Application Number | 20100179589 12/684569 |
Document ID | / |
Family ID | 42319600 |
Filed Date | 2010-07-15 |
United States Patent
Application |
20100179589 |
Kind Code |
A1 |
Roorda; Wouter E. ; et
al. |
July 15, 2010 |
RAPIDLY ERODING ANCHOR
Abstract
An anchor for using a closure device includes a body being
configured to move from a pre-deployed state to a deployed state.
In the pre-deployed state, the body has a first width aspect
relative to a direction of deployment and a second width aspect in
the deployed state relative to the direction of deployment, the
second width aspect being greater than the first width aspect and
wherein the body is formed from a rapidly eroding material
configured to erode through dissolution within a body lumen.
Inventors: |
Roorda; Wouter E.; (Palo
Alto, CA) ; Voss; Laveille K.; (Belmont, CA) ;
McCrystle; Kelly J.; (Menlo Park, CA) ; Osman; Karim
S.; (Mountain View, CA) |
Correspondence
Address: |
WORKMAN NYDEGGER
1000 EAGLE GATE TOWER,, 60 EAST SOUTH TEMPLE
SALT LAKE CITY
UT
84111
US
|
Assignee: |
ABBOTT VASCULAR INC.
Santa Clara
CA
|
Family ID: |
42319600 |
Appl. No.: |
12/684569 |
Filed: |
January 8, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61143751 |
Jan 9, 2009 |
|
|
|
Current U.S.
Class: |
606/213 |
Current CPC
Class: |
A61B 17/0057 20130101;
A61L 31/146 20130101; A61L 2400/04 20130101; A61B 2017/00623
20130101; A61B 2017/0061 20130101; A61L 31/042 20130101; A61B
2017/00663 20130101; A61B 2017/00637 20130101; A61L 31/06 20130101;
A61B 17/0401 20130101; A61L 31/048 20130101; A61B 2017/00004
20130101; A61L 31/16 20130101; A61B 2017/00654 20130101; A61B
2017/00659 20130101; A61L 31/148 20130101; A61B 2017/00668
20130101 |
Class at
Publication: |
606/213 |
International
Class: |
A61B 17/08 20060101
A61B017/08 |
Claims
1. An anchor for using a closure device, the anchor comprising: a
body being configured to move from a pre-deployed state to a
deployed state, wherein in the pre-deployed state the body has a
first width aspect relative to a direction of deployment and a
second width aspect in the deployed state relative to the direction
of deployment, the second width aspect being greater than the first
width aspect and wherein the body is formed from a rapidly eroding
material configured to erode through dissolution within a body
lumen.
2. The anchor of claim 1, wherein the body is configured to erode
in less than twelve hours.
3. The anchor of claim 1, wherein the body is configured to erode
in less than one hour.
4. The anchor of claim 1, wherein the body includes a major axis
and wherein the body is configured to rotate in response to a force
applied parallel to the major axis.
5. The anchor of claim 1, wherein the rapidly eroding material
includes at least one of a sugar and a sugar-derivative.
6. The anchor of claim 5, wherein the sugar derivative includes
sugar alcohols including mannitol, sorbitol, and isomalt.
7. The anchor of claim 5, wherein the sugar includes at least one
of a group including glucose, fructose, lactose and maltose.
8. The anchor of claim 1, wherein the body further includes at
least one polymeric component.
9. The anchor of claim 8, wherein the polymeric component includes
at least one of poly-vinylpyrrolidone, poly-ethyleneglycol,
hydroxyethyl starch, dextran or dextran sulfate.
10. The anchor of claim 1, wherein the rapidly eroding material is
water soluble.
11. The anchor of claim 1, wherein the rapidly eroding material
forms a crystalline matrix.
12. The anchor of claim 1, wherein the rapidly eroding material
forms a glass structure.
13. The anchor of claim 1, wherein the rapidly eroding material
includes a plurality of pores.
14. The anchor of claim 13, wherein at least one of the pores
includes at least one beneficial agent.
15. The anchor of claim 13, wherein the anchor member includes at
least one of poly-vinyl pyrrolidone, hyaluronic acid, dextran,
hydrogel, heparin, and benzalkonium heparin.
16. The closure device of claim 1, wherein the anchor member is
formed using a freeze-drying process.
17. A method of closing a puncture in a wall of a body lumen,
comprising: advancing an anchor in a deployment direction through
the anchor, the anchor having a first width aspect relative to the
deployment direction; deploying the anchor distally of the wall of
the body lumen to cause the anchor to move to have a second width
aspect relative to the deployment direction, the second width
aspect being larger than the first width aspect; drawing the anchor
distally into engagement with a distal side of the wall of the body
lumen; and deploying a closure element into the wall of the body
lumen, wherein the anchor is formed from a rapidly eroding material
that dissolves in the body lumen in less than twelve hours.
18. The method of claim 17, wherein rapidly eroding material
dissolves in the body lumen in less than one hour.
19. The method of claim 17, wherein deploying a closure element
includes deploying an expandable plug.
20. The method of claim 17, wherein deploying a closure element
includes deploying tines into the wall of the body lumen.
21. A closure device system comprising: a delivery sheath; a
rapidly eroding anchor at least partially disposed within the
delivery sheath in an initial configuration, the closure member
comprising one or more sugars; a suture element coupled to the
closure member and disposed at least partially through the delivery
sheath; and a pusher disposed at least partially within the
delivery sheath and configured to deploy the anchor member from a
distal end of the delivery sheath.
22. The closure device system of claim 21, further comprising an
expandable plug configured to be positioned between the anchor and
the pusher.
23. The closure device system of claim 21, further comprising an
expandable closure element configured to be moved between an
expanded state and a restricted state to close a puncture in a wall
of a body lumen.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of and priority
to U.S. Provisional Patent Application Ser. No. 61/143,751,
entitled "Vessel Closure Devices and Methods," filed Jan. 9, 2009,
the disclosure of which is incorporated herein by reference in its
entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates generally to medical devices
and their methods of use. In particular, the present disclosure
relates to vessel closure systems and devices and corresponding
methods of use.
[0004] 2. The Technology
[0005] Catheterization and interventional procedures, such as
angioplasty or stenting, generally are performed by inserting a
hollow needle through a patient's skin and tissue into the vascular
system. A guidewire may be advanced through the needle and into the
patient's blood vessel accessed by the needle. The needle is then
removed, enabling an introducer sheath to be advanced over the
guidewire into the vessel, e g in conjunction with or subsequent to
a dilator.
[0006] A catheter or other device may then be advanced through a
lumen of the introducer sheath and over the guidewire into a
position for performing a medical procedure. Thus, the introducer
sheath may facilitate introducing various devices into the vessel,
while minimizing trauma to the vessel wall and/or minimizing blood
loss during a procedure.
[0007] Upon completing the procedure, the devices and introducer
sheath would be removed, leaving a puncture site in the vessel
wall. Traditionally, external pressure would be applied to the
puncture site until clotting and wound sealing occur. However, the
patient must remain bedridden for a substantial period after
clotting to ensure closure of the wound. This procedure may be time
consuming and expensive, requiring as much as an hour of a
physician's or nurse's time. It is also uncomfortable for the
patient and requires that the patient remain immobilized in the
operating room, catheter lab, or holding area. In addition, a risk
of hematoma exists from bleeding before hemostasis occurs.
BRIEF SUMMARY
[0008] An anchor for using a closure device may include a body
being configured to move from a pre-deployed state to a deployed
state. In the pre-deployed state, the body has a first width aspect
relative to a direction of deployment and a second width aspect in
the deployed state relative to the direction of deployment, the
second width aspect being greater than the first width aspect and
wherein the body is formed from a rapidly eroding material
configured to erode through dissolution within a body lumen.
[0009] A method of closing a puncture in a wall of a body lumen may
include advancing an anchor in a deployment direction through the
anchor, the anchor having a first width aspect relative to the
deployment direction, deploying the anchor distally of the wall of
the body lumen to cause the anchor to move to have a second width
aspect relative to the deployment direction, the second width
aspect being larger than the first width aspect, drawing the anchor
distally into engagement with a distal side of the wall of the body
lumen, and deploying a closure element into the wall of the body
lumen, wherein the anchor is formed from a rapidly eroding material
that dissolves in the body lumen in less than twelve hours.
[0010] A closure device system may include a delivery sheath, a
rapidly eroding anchor at least partially disposed within the
delivery sheath in an initial configuration, the closure member
comprising one or more sugars, a suture element coupled to the
closure member and disposed at least partially through the delivery
sheath, and a pusher disposed at least partially within the
delivery sheath and configured to deploy the anchor member from a
distal end of the delivery sheath.
[0011] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and are intended to provide further explanation of the invention
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] To further clarify the above and other advantages and
features of the present disclosure, a more particular description
of the disclosure will be rendered by reference to specific
embodiments thereof which are illustrated in the appended drawings.
It is appreciated that these drawings depict only illustrated
embodiments of the disclosure and are therefore not to be
considered limiting of its scope. The disclosure will be described
and explained with additional specificity and detail through the
use of the accompanying drawings in which:
[0013] FIGS. 1A-1C illustrate a closure device in which a rapidly
eroding anchor can be implemented according to one example;
[0014] FIGS. 1D-1F illustrate a method of closing a puncture in a
wall of a body lumen in which a rapidly eroding anchor can be
implemented;
[0015] FIGS. 2A-2E illustrate a closure device and a method for
closing a puncture in a wall of a body lumen in which a rapidly
eroding anchor can be implemented according to one example; and
[0016] FIG. 3 illustrates a closure device and a method for closing
a puncture in a wall of a body lumen in which a rapidly eroding
anchor can be implemented according to one example.
DETAILED DESCRIPTION
[0017] The present disclosure relates to devices, systems, and
methods for closing an opening in a body lumen. For example, the
present disclosure includes an anchor, such as an intra-arterial
"foot," comprising a rapidly eroding material. The anchor may be
passed through an opening defined in a wall of a body lumen and
deployed. The anchor can then be drawn proximally to draw the
anchor into contact with a distal side of the body lumen wall. A
closure element can then be deployed to close the puncture.
[0018] In at least one example, once deployed within a body lumen,
the anchor may dissolve in less than a day or even less than an
hour as desired. The rapid erosion of the anchor can allow the
anchor to be left in place after the closure element has been
deployed by obviating the need for removal of the anchor. By
leaving the anchor in place until it dissolves, damage that may
occur by drawing the anchor through the closed puncture and/or the
deployed closure element can be reduced or eliminated.
[0019] In addition, the erosion time of the anchor may fall within
the time frame of the action of an anti-thrombotic medication being
used in conjunction with the treatment of a patient. Accordingly,
the closure element of the present disclosure may reduce the risk
of formation of intra-arterial clots associated with the closure of
the body lumen opening.
[0020] Reference is now made to FIG. 1A, which illustrates a
closure device 100 according to one example. As shown in FIG. 1A,
the closure device 100 may include a delivery sheath 110 and a
pusher 120 that are configured to cooperate to deploy an anchor
130, such as an intra-arterial foot, and a closure element 140,
such as a plug, and a suture element 150. In at least one example,
the delivery sheath 110 is configured to house the anchor 130 and
the closure element 140 while the pusher 120 is configured to
deploy the anchor 130 and/or the closure element 140 from the
delivery sheath 110. The exemplary delivery sheath 110, pusher 120,
anchor 130, and closure element 140 of FIG. 1A will be discussed in
more detail with reference to FIG. 1B.
[0021] FIG. 1B illustrates an exploded view of the closure device
100. As shown in FIG. 1B, the delivery sheath 110 includes an outer
housing 112 and a grip portion 114 while the pusher 120 includes a
handle portion 122 and a shaft portion 124. An interior lumen 116
is defined in the outer housing 112 that is configured to receive
the pusher 120 in such a manner as to allow the pusher 120 to be
extended from and retracted within a distal end 112A of the outer
housing 112. For example, the interior lumen 116 can include a
first portion 116A configured to receive the shaft portion 124 of
the pusher 120 while a second portion 116B of the interior lumen
116 can be configured to receive a distal end 124A of the shaft
portion 124.
[0022] More specifically, the second portion 116B of the interior
lumen 116 may have a larger width aspect than the width aspect of
the first portion 116A. The width aspects of the first portion 116A
and the second portion 116B can be the diameters thereof or other
cross sectional profiles that are generally transverse to a center
axis C of the delivery sheath 110. For ease of reference, the
center axis C of the delivery sheath 110 will be referenced in
describing the position and movement of the other components
described herein. In the illustrated example, the interior lumen
116 may transition from the smaller diameter of the first portion
116A to a second larger diameter of the second portion 116B at a
shoulder 118.
[0023] Such a configuration can allow the pusher 120 to translate
axially relative to the delivery sheath 110 within a desired range
of motion. In particular, the handle portion 122 can translate
within the second portion 116B of the interior lumen 116 to advance
the shaft portion 124 within the outer housing 112 to thereby move
the distal end 124A of the shaft portion 124 relative to the distal
end 112A of the outer housing 112. Interaction between the handle
portion 122 and the shoulder 118 can help ensure the distal end
124A does not extend beyond a desired position within the outer
housing 112.
[0024] In the illustrated example, the first portion 116A may also
be configured to receive the anchor 130 and the closure element 140
proximally of the distal end 124A of the shaft portion 124.
Accordingly, as the distal end 124A of the shaft portion 124 is
advanced toward the distal end 112A of the outer housing 112, the
distal end 124A of the shaft portion 124 can engage the anchor 130
and/or the closure element 140 to move the anchor 130 and/or the
closure element 140 distally from the outer housing 112.
[0025] The anchor 130 can be configured to move from a pre-deployed
state having a pre-deployed width aspect to a deployed state having
a deployed width aspect. The deployed width aspect may be greater
than the pre-deployed width aspect. The anchor 130 can have any
configuration that allows for this. In the illustrated example,
anchor 130 is configured to rotate or be rotated between the
pre-deployed state and the deployed state. In other examples, the
anchor 130 may be configured to unfold from a configuration have a
pre-deployed width aspect to a deployed state having a greater
width aspect. For example, one or more arms may be configured to
unfold and fold about a plurality of pivot or hinge points.
[0026] As shown in FIG. 1B, the anchor 130 includes leg members
132, 134 that define a major axis 136 of the anchor 130. The anchor
130 can further include an eyelet 138 coupled to one or both of the
leg members 132, 134. The eyelet 138 can be located at a position
that causes the anchor 130 to rotate when a force acting initially
parallel to the major axis 136 is exerted on the eyelet 138. Such a
configuration can allow the anchor 130 to move from a state in
which the major axis 136 is aligned with the central axis C to a
state in which the major axis 136 is oriented more obliquely to the
central axis C, such as generally perpendicular to the central axis
C.
[0027] This rotation can be accomplished by applying a distally
acting force on the anchor 130 to move the anchor 130 out of the
outer housing 112 and then a proximally directed force to the
anchor 130 by way of the eyelet 138. In at least one example, the
distally acting force applied to the anchor 130 can be provided
from the pusher 120 by way of the closure element 140 while the
proximally directed force can be applied by way of the suture
element 150. The anchor 130 can thus be used to position the
closure device 100 for deployment of the closure element 140.
[0028] In one embodiment, the closure element 140 may be configured
to close an opening in a lumen as well as at least partially
obstruct a tissue tract leading from an external surface of the
tissue to the lumen. The shape of the closure element 140 may be
configured to be housed within the first portion 116A of the
interior lumen 116. For example, the closure element 140 may
conform to the shape of the interior lumen 116. In one embodiment,
the closure element 140 may be cylindrical in shape prior to being
deployed from the delivery sheath 110. Once deployed from the
delivery sheath 110, the closure element 140 may be deformable to
conform to any desired shape to close an opening in a body lumen
and/or the tissue tract leading to the lumen opening.
[0029] As shown, the example pusher 120 can be coupled to the
closure element 140 and/or anchor 130 by way of the suture element
150. In particular, the suture element 150 can loop through the
anchor 130 such that the suture element 150 has two free ends that
pass through or near the closure element 140, and extend proximally
into or beyond the handle portion 122 of the pusher 120. In at
least one example, the free ends of the suture element 150 pass
through separate portions or channels of the closure element 140.
In one embodiment, the pusher 120 can have a suture lumen 126
defined therein that extends through the shaft portion 124 and
extends proximally to or even through the handle portion 122. The
suture element 150 can be extended from the closure element 140 and
into the pusher 120 by way of the suture lumen 126.
[0030] In one embodiment, the delivery sheath 110 may include a
guidewire lumen 160 with a proximal guidewire port 162 therein near
the proximal end 112B of the outer housing 112 and a distal
guidewire port 164 near the distal end 112A of the outer housing
112. The guidewire lumen 160 may be at least partially integrated
or entirely distinct from the interior lumen 116 of the delivery
sheath 110. Accordingly, a guidewire can enter the proximal
guidewire port 162, pass through the guidewire lumen 160, and exit
the distal guidewire port 164. As a result, the example closure
device 100 can advance over a guidewire and into position with a
lumen opening as part of a method to close the lumen opening. One
such method will now be discussed in more detail with reference to
FIGS. 1C-1F.
[0031] Reference is now made to FIG. 1C, which illustrates a step
in the process of deploying the anchor 130. As shown in FIG. 1C,
the delivery sheath 110 can be positioned to move the distal end
112A of the outer housing 112 through a tract 170 defined in tissue
172 and into proximity with a lumen 174 and a puncture 176 defined
in a lumen wall 178 in particular.
[0032] Thereafter, as shown in FIG. 1D, the pusher 120 can be
manipulated as described above to cause the anchor 130 to be pushed
out of the distal end 112A of the outer housing 112. For example,
the pusher 120 may push the closure element 140 which may, in turn,
push the anchor 130 distally relative to the outer housing 112,
thereby deploying the anchor 130 from the distal end 112A of the
outer housing 112. In one embodiment, once deployed, the anchor 130
may rotate or be rotated from a first orientation, in which the
major axis 136 of the anchor 130 is at a small angle or generally
parallel with the outer housing 112 and generally perpendicular to
the lumen wall 178 as shown in FIG. 1C, to a second orientation in
which the major axis 136 of the anchor 130 is generally parallel
with the lumen 170 and at a greater angle or generally
perpendicular to the delivery sheath 110 as shown in FIG. 1D.
[0033] In particular, as shown in FIG. 1D, once the anchor 130 is
pushed from the distal end 112A of the outer housing 112, the
anchor 130 may rotate or be rotated to the second orientation, such
as by tension applied to by the suture element 150 to the anchor
130 by way of the eyelet 138. The anchor 130 can then be drawn in
the proximal direction to secure the anchor 130 against a distal
surface 178A of the lumen wall 178. The anchor 130 may comprise any
of a number of different materials. In one example, the anchor 130
may comprise a bioabsorbable material. In a further embodiment, the
anchor 130 may comprise a rapidly eroding material as disclosed in
more detail herein.
[0034] As also shown in FIG. 1D, the anchor 130 can be used to
stabilize tissue around the puncture 176 in order to facilitate
closure of the puncture 176. In particular, once the anchor 130 is
deployed, the anchor 130 may then be secured against a distal side
178A of the lumen wall 178 by pulling the suture element 150, which
is coupled to the anchor 130, proximally. In one example, a suture
lock (not shown) can be utilized to help maintain the tension in
the suture element 150. Once the anchor 130 is secured against the
distal side 178A of the lumen wall 178, the outer housing 112 may
be advanced distally. In particular, the outer housing 112 can be
advanced to exert a force against a proximal side 178B of the lumen
wall 178. The combination of the forces exerted by the anchor 130
and the outer housing 112 on the lumen wall 178 may result in a
compressive force on the tissue near the puncture 176. As a result,
the puncture 176 may be compressed and/or located by the delivery
sheath 110 and the outer housing 112 in particular. This may allow
an adjustable sandwiching and location of the lumen opening by the
combination of tension in the suture element 150 and compression
created by the delivery sheath 110.
[0035] With the anchor 130 deployed, the pusher 120 may then deploy
the closure element 140 within the puncture 176 and/or the tract
170 near a proximal side 178B of the lumen wall 178. In particular,
as shown in FIG. 1E the pusher 120 can be advanced distally, the
delivery sheath 110 can be drawn proximally, and/or some
combination of such movements can be used to move the closure
element 140 distally out of the outer housing 112 and into contact
with the proximal side 178B of the lumen wall 178 adjacent the
puncture 176.
[0036] In such a step, the lumen wall 178 is positioned between the
anchor 130 and the closure element 140. Thus, the closure element
140 can be positioned to reduce or stop the flow of fluid out of
the tract 170 by covering the puncture 176 and/or obstructing the
tract 170.
[0037] In one embodiment, the pusher 120 remains in continuous
contact with the closure element 140 throughout the deployment
process. Such a configuration can allow the anchor 130 and/or
closure element 140 to be deployed by advancing the pusher 120 in a
single direction. By facilitating deployment of the anchor 130 and
closure element 140 using one-way movement of the pusher 120, and
by utilizing a single pusher 120, the closure device 100 may result
in a quicker and easier deployment of the anchor 130 and/or closure
element 140.
[0038] The engagement of the anchor 130 and the closure element 140
to the lumen wall 178 may be secured in any desired manner. In at
least one example, the free ends of the suture element 150 may pass
from the anchor 130 through the closure element 140. In such an
example, a suture lock and/or a knot pusher can be used to advance
a knot into proximity with the closure element 140 and tighten the
knot to thereby maintain tension between the anchor 130 and the
closure element 140. A suture cutter can then sever the suture
element 150. A suture lock, a knot pusher, and/or a suture cutter
can be advanced through a suture lumen 126 defined in the pusher
120 either before or after the delivery sheath 110 and the pusher
120 are withdrawn from the tract 170. As a result, the suture
element anchor 130, closure element 140, and suture element 150 can
remain in the tissue tract 170 as shown in FIG. 1F.
[0039] As previously introduced, the anchor 130 can be formed of a
rapidly eroding material that allows the anchor 130 to be left in
place within the lumen 174. The composition of the anchor 130
allows the anchor 130 to remain in position for a long enough
period to enable the closure procedure and a short enough period to
allow sufficient erosion of the anchor 130 while the patient is
still under physician control or in the hospital. This time period
can therefore be in a range of roughly between 30 minutes and 12
hours. The anchor 130 may be formed of a material that is strong
enough to allow for secure anchoring of a closure element, such as
the plug and/or other closure elements described below.
[0040] Further, the anchor 130 may be formed of a material that is
biocompatible in an intravascular environment and non-thrombogenic.
An anchor with these characteristics may be obtained by using a
mechanism of dissolution rather than chemical degradation. Rapidly
dissolving compounds that are suitable include, but are not limited
to, sugars and sugar-derivatives like sugar-alcohols.
Representative examples are sugars like glucose, fructose, lactose,
maltose, and sugar alcohols like mannitol, sorbitol and isomalt.
Strength can be added to the formulation by including a polymeric
component, such as poly-vinylpyrrolidone, poly-ethyleneglycol, or a
polysaccharide like starch, hydroxyethylstarch, dextran or dextran
sulfate. Sugar alcohols such as mannitol, sorbitol, and isomalt
have relatively low melting points, and form good solvents for the
polysaccharides. This can facilitate manufacturing, since a simple
melt process can be used. Various mixtures of these components are
possible, resulting in potentially different anchor properties.
Hydroxyethyl starch has a relatively low glass transition
temperature, and so has a mannitol-sorbitol mixture. A solution of
hydroxyethyl starch in mannitol-sorbitol, when solidified, may have
a glass transition below body temperature, which will create a
tough, but not brittle anchor. On the other end of the spectrum, a
mixture of dextran with isomalt has a much higher glass transition,
resulting in a very hard and strong anchor, but with higher
brittleness. Since all these components are miscible, a wide range
of properties can be achieved by mixing them in corresponding
proportions to achieve the desired properties.
[0041] In one embodiment, the rapidly eroding material can be
configured to be at least partially porous and/or micro-porous.
Accordingly, one or more beneficial agents can be incorporated into
at least one of the pores of the rapidly eroding material. For
example, the beneficial agents may include anti-clotting agents,
such as heparin, anti-inflammatory agents, and/or other beneficial
agents. One method for producing a porous rapidly eroding material
may include freeze drying the rapidly eroding material. In
particular, in one example embodiment, acetic acid may be used as a
solvent for freeze drying the rapidly eroding material. Polymers,
such as PLGA, which are soluble in acetic acid, may be used as part
of the freeze-drying process.
[0042] In a further embodiment, a micro-porous silicon may be used.
In particular, the micro-porous silicon may be prepared with
various degradation rates, including rapidly degrading forms. The
micro-porous silicon may be sufficiently strong to be used in an
anchor, such as a bioerodible foot, and/or may also have sufficient
porosity to allow incorporation of beneficial agents. For example,
in one embodiment, it may be desirable to incorporate a hydrophobic
heparin derivative, such as benzalkonium heparin, into the porosity
of the anchor because of its low solubility. The closure element
140 may comprise any number of different materials suitable for use
as a plug.
[0043] FIG. 2A illustrates a closure device 200 in which an anchor
130' similar to the anchor 130 described above may be implemented.
In the illustrated example, the closure device 200 can include a
delivery sheath 110' having an outer housing 112' and a grip
portion 114'. An interior lumen 116' is defined in the outer
housing 112' configured to house the anchor 130'. The closure
device 200 further includes deployment assembly 210 that includes a
garage sheath 220 configured to house an actuator member 230, which
in turn can be configured to house a carrier tube 240, which in
turn is configured to house a pusher 120'.
[0044] The pusher 120' can be configured to translate axially
within the carrier tube 240 to deploy the anchor 130' from the
closure device 200. A closure element 250 is configured to be
positioned on the carrier tube 240. As will be discussed in more
detail below, distal movement of the actuator member 230 relative
to the carrier tube 240 may deploy the closure element 250.
[0045] In the illustrated example, the garage sheath 220 includes a
housing portion 222 coupled to a plunger portion 224. The first
plunger portion 224 can be positioned proximally of the grip
portion 114' of the delivery sheath 110. The actuator member 230
can include a housing portion 232 and a second plunger portion 234.
The carrier tube 240 can also include a housing portion 242 and a
third plunger portion 244. The pusher 120' includes a handle
portion 122' and a shaft portion 124'.
[0046] As shown in FIG. 2B, the pusher 120' can be used to deploy
the anchor 130' from the delivery sheath 110' using a suture
element 150' in a similar manner as described above. Once the
anchor 130' is deployed, the first plunger portion 224 can be
advanced proximally relative to the delivery sheath 110' along with
the second plunger portion 234 and the third plunger portion 244 to
position the deployment assembly 210 in proximity with the lumen
wall 178.
[0047] Thereafter, as shown in FIG. 2C, the first plunger portion
224 may be drawn proximally toward the second plunger portion 234
and the third plunger portion 244, the second plunger portion 234
and the third plunger portion 244 may be advanced distally, and/or
some combination of those movements may be performed to expose the
actuator member 230 and the carrier tube 240 from the garage sheath
220 while maintaining the carrier tube 240 in engagement with the
lumen wall 178. In such an example, the delivery sheath 110' can
remain in place to maintain the lumen wall 178 between the delivery
sheath 110' and the anchor 130'.
[0048] As shown in FIG. 2D, the second plunger portion 234 can then
be advanced distally relative to the third plunger portion 244 to
expand and deploy the closure element 250. In particular, as shown
in FIG. 2D, the carrier tube 240 includes ramped portions 246. As
the second plunger portion 234 advances distally relative to the
third plunger portion 244, the actuator member 230 pushes the
closure element 250 over the ramped portions 246 of the carrier
tube, thereby expanding the closure element 250. Thereafter, the
closure device 200 can be removed and the suture element 250 cut as
described above.
[0049] Continued advancement of the actuator member 230 distally
relative to the carrier tube 240 moves tissue-engaging portions 252
of the closure element 250 into engagement with the lumen wall 178.
Further distal movement of the actuator member 230 pushes the
closure element 250 distally of the carrier tube 240. In at least
one example, the closure element 250 can be formed of a resilient
material having a trained or default state having a narrow
diameter. The closure element 250 can be partially expanded onto
the carrier tube 240 prior deployment. As the closure element 250
moves distally from the carrier tube 240, the closure element 250
can move toward the trained or default state, thereby closing the
puncture 176.
[0050] As shown in FIG. 2E, once the closure element 250 is
deployed, a plug material 260 may be injected near the lumen wall
and within the tract 170. A suture element 150' may be secured,
such as by knotting, and then severed, thereby leaving the anchor
130', closure element 250, and plug 260 in place while the
remaining components of the closure device 200 are retracted.
Thereafter, the rapidly eroding material of the anchor 130' may
then dissolve into the fluid flow within the lumen. In another
example, the anchor maybe dissolved soon after the procedure
allowing the suture element 250 to be removed and obviating the use
of the plug material 260. In still further examples, the anchor
130' may be let go down stream by slipping off the suture from the
anchor, thus leaving behind only the closure element 250.
[0051] FIG. 3 illustrates a closure device 200' configured for use
as an over-the wire deployment that is similar to the closure
device 200 shown in FIGS. 2A-2E. The closure device 250' may be
advanced over a guidewire 300. In the example shown in FIG. 3, the
delivery sheath 110' and garage sheath 220 of FIGS. 2A-2E have been
omitted. In such an example, the anchor 130' can be housed within
the carrier tube 240 and pushed distally using a pusher 120'
translating therein. Thereafter, the closure device 200' can deploy
the anchor 130' and the closure element 250 in a similar manner as
described above with reference to FIGS. 2A-2E by advancing an
actuator member 230 relative to a carrier tube 240.
[0052] Embodiments of the closure element, the delivery sheath, and
the like may include a material made from any of a variety of known
suitable biocompatible materials, such as a biocompatible shape
memory material (SMM). For example, the SMM may be shaped in a
manner that allows for a delivery orientation while within the tube
set, but may automatically retain the memory shape of the component
once deployed into the tissue to close the opening. SMMs have a
shape memory effect in which they may be made to remember a
particular shape. Once a shape has been remembered, the SMM may be
bent out of shape or deformed and then returned to its original
shape by unloading from strain or heating. Typically, SMMs may be
shape memory alloys (SMA) comprised of metal alloys, or shape
memory plastics (SMP) comprised of polymers. The materials may also
be referred to as being superelastic.
[0053] Usually, an SMA may have an initial shape that may then be
configured into a memory shape by heating the SMA and conforming
the SMA into the desired memory shape. After the SMA is cooled, the
desired memory shape may be retained. This allows for the SMA to be
bent, straightened, twisted, compacted, and placed into various
contortions by the application of requisite forces; however, after
the forces are released, the SMA may be capable of returning to the
memory shape. The main types of SMAs are as follows:
copper-zinc-aluminum; copper-aluminum-nickel; nickel-titanium
(NiTi) alloys known as nitinol; nickel-titanium platinum;
nickel-titanium palladium; and cobalt-chromium-nickel alloys or
cobalt-chromium-nickel-molybdenum alloys known as elgiloy alloys.
The temperatures at which the SMA changes its crystallographic
structure are characteristic of the alloy, and may be tuned by
varying the elemental ratios or by the conditions of manufacture.
This may be used to tune the component so that it reverts to the
memory shape to close the arteriotomy when deployed at body
temperature and when being released from the tube set.
[0054] For example, the primary material of a closure element and
the like may be of a NiTi alloy that forms superelastic nitinol. In
the present case, nitinol materials may be trained to remember a
certain shape, retained within the tube set, and then deployed from
the tube set so that the tines penetrate the tissue as it returns
to its trained shape and closes the opening. Also, additional
materials may be added to the nitinol depending on the desired
characteristic. The alloy may be utilized having linear elastic
properties or non-linear elastic properties.
[0055] An SMP is a shape-shifting plastic that may be fashioned
into a closure element in accordance with the present disclosure.
Also, it may be beneficial to include at least one layer of an SMA
and at least one layer of an SMP to form a multilayered body;
however, any appropriate combination of materials may be used to
form a multilayered device. When an SMP encounters a temperature
above the lowest melting point of the individual polymers, the
blend makes a transition to a rubbery state. The elastic modulus
may change more than two orders of magnitude across the transition
temperature (Ttr). As such, an SMP may be formed into a desired
shape of an endoprosthesis by heating it above the Ttr, fixing the
SMP into the new shape, and cooling the material below Ttr. The SMP
may then be arranged into a temporary shape by force and then
resume the memory shape once the force has been released. Examples
of SMPs include, but are not limited to, biodegradable polymers,
such as oligo(.epsilon.-caprolactone)diol,
oligo(.rho.-dioxanone)diol, and non-biodegradable polymers such as,
polynorborene, polyisoprene, styrene butadiene, polyurethane-based
materials, vinyl acetate-polyester-based compounds, and others yet
to be determined. As such, any SMP may be used in accordance with
the present disclosure.
[0056] The closure element, the delivery sheath, and the like may
have at least one layer made of an SMM or suitable superelastic
material and other suitable layers may be compressed or restrained
in its delivery configuration within the garage tube or inner
lumen, and then deployed into the tissue so that it transforms to
the trained shape. For example, the closure element may be set in a
trained shape that has a relative small diameter. The closure
element can then be expanded and moved into engagement with a body
lumen wall adjacent a puncture. The closure element can then be
allowed to return to the trained state to close the puncture.
[0057] Also, a closure element, the delivery sheath or other
aspects or components of the closure system may be comprised of a
variety of known suitable deformable materials, including stainless
steel, silver, platinum, tantalum, palladium, nickel, titanium,
nitinol, having tertiary materials (U.S. 2005/0038500, which is
incorporated herein by reference, in its entirety),
niobium-tantalum alloy optionally doped with a tertiary material
(U.S. 2004/0158309, 2007/0276488, and 2008/0312740, which are each
incorporated herein by reference, in their entireties)
cobalt-chromium alloys, or other known biocompatible materials.
Such biocompatible materials may include a suitable biocompatible
polymer in addition to or in place of a suitable metal.
[0058] In one embodiment, the closure element, the delivery sheath,
and the like may be made from a superelastic alloy such as
nickel-titanium or nitinol, and includes a ternary element selected
from the group of chemical elements consisting of iridium,
platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum,
silver, ruthenium, or hafnium. The added ternary element improves
the radiopacity of the nitinol.
[0059] In one embodiment, the closure element, the delivery sheath,
and the like may be made at least in part of a high strength, low
modulus metal alloy comprising Niobium, Tantalum, and at least one
element selected from the group consisting of Zirconium, Tungsten,
and Molybdenum.
[0060] In further embodiments, the closure element, the delivery
sheath, and the like may be made from or be coated with a
biocompatible polymer. Examples of such biocompatible polymeric
materials may include hydrophilic polymer, hydrophobic polymer
biodegradable polymers, bioabsorbable polymers, and monomers
thereof. Examples of such polymers may include nylons,
poly(alpha-hydroxy esters), polylactic acids, polylactides,
poly-L-lactide, poly-DL-lactide, poly-L-lactide-co-DL-lactide,
polyglycolic acids, polyglycolide, polylactic-co-glycolic acids,
polyglycolide-co-lactide, polyglycolide-co-DL-lactide,
polyglycolide-co-L-lactide, polyanhydrides,
polyanhydride-co-imides, polyesters, polyorthoesters,
polycaprolactones, polyesters, polyanydrides, polyphosphazenes,
polyester amides, polyester urethanes, polycarbonates,
polytrimethylene carbonates, polyglycolide-co-trimethylene
carbonates, poly(PBA-carbonates), polyfumarates, polypropylene
fumarate, poly(p-dioxanone), polyhydroxyalkanoates, polyamino
acids, poly-L-tyrosines, poly(beta-hydroxybutyrate),
polyhydroxybutyrate-hydroxyvaleric acids, polyethylenes,
polypropylenes, polyaliphatics, polyvinylalcohols,
polyvinylacetates, hydrophobic/hydrophilic copolymers,
alkylvinylalcohol copolymers, ethylenevinylalcohol copolymers
(EVAL), propylenevinylalcohol copolymers, polyvinylpyrrolidone
(PVP), combinations thereof, polymers having monomers thereof, or
the like.
[0061] The present disclosure may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the disclosure is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes which come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *