U.S. patent application number 14/038584 was filed with the patent office on 2014-01-30 for delivery systems and methods for pfo closure device with two anchors.
This patent application is currently assigned to W.L. Gore & Associates, Inc.. Invention is credited to Andrzej J. Chanduszko.
Application Number | 20140031862 14/038584 |
Document ID | / |
Family ID | 35450023 |
Filed Date | 2014-01-30 |
United States Patent
Application |
20140031862 |
Kind Code |
A1 |
Chanduszko; Andrzej J. |
January 30, 2014 |
Delivery Systems and Methods for PFO Closure Device with Two
Anchors
Abstract
A device closes septal openings, such as a patent foramen ovale
(PFO). The device includes two anchors and a flexible connector.
Tension applied to one or more strings attached to the device
causes the device to collapse into a reduced profile form for
withdrawal into a delivery catheter, thereby facilitating retrieval
of the device after insertion into a septal opening.
Inventors: |
Chanduszko; Andrzej J.;
(Chandler, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
& |
Flagstaff |
AZ |
US |
|
|
Assignee: |
W.L. Gore & Associates,
Inc.
Flagstaff
AZ
|
Family ID: |
35450023 |
Appl. No.: |
14/038584 |
Filed: |
September 26, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13651643 |
Oct 15, 2012 |
8568447 |
|
|
14038584 |
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|
11110975 |
Apr 20, 2005 |
8308760 |
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13651643 |
|
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60568527 |
May 6, 2004 |
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Current U.S.
Class: |
606/213 |
Current CPC
Class: |
A61B 2017/00575
20130101; A61B 17/0057 20130101; A61B 2017/00862 20130101; A61B
2017/00867 20130101; A61B 2017/00243 20130101; A61B 2017/00606
20130101; A61B 2017/00592 20130101; A61B 2017/00623 20130101 |
Class at
Publication: |
606/213 |
International
Class: |
A61B 17/00 20060101
A61B017/00 |
Claims
1. A septal occluder comprising: a proximal anchor member for
deployment proximate a first side of a septal defect, the proximal
anchor having a substantially cylindrical shape cut out to form; a
flat axial face over a portion of the length at one end and a flat
radial face and a radial passage extending along a diameter of the
proximal anchor; a distal anchor member for deployment proximate a
second side of the septal defect; a flexible connector connecting
the proximal and distal anchor members; and a first ball and a
second ball disposed at opposite ends of the radial passage of the
proximal anchor, the second ball being larger in diameter than the
passage, wherein the first and second balls are connected to one
another by a removal string for retrieving the device from its
intended delivery location.
2. The occluder of claim 1, wherein the balls are spherical.
3. The occluder of claim 2, wherein the balls are coupled to a wire
in conjunction with a holder that can push or pull them.
4. The occluder of claim 3, wherein the holder is a grappling
hook.
5. The occluder of claim 1, wherein the balls are coupled to a
hemispheric piece to serve as a stop.
6. The occluder of claim 1, wherein a tension applied to the
removal string causes the ball stop to pass through the radial
passage, thereby causing the occluder to collapse into a form
suitable for withdrawal into a delivery sheath.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S.
application Ser. No. 13/651,643 filed Oct. 15, 2012, now pending;
which is a continuation application of U.S. application Ser. No.
11/110,975 filed Apr. 20, 2005, now issued as U.S. Pat. No.
8,308,760; which claims the benefit under 35 USC .sctn.119(e) to
U.S. application Ser. No. 60/568,527 filed May 6, 2004, now
expired. The disclosure of each of the prior applications is
considered part of and is incorporated by reference in the
disclosure of this application.
BACKGROUND OF THE INVENTION
[0002] The invention relates to devices and methods that are used
to close septal openings, such as a patent foramen ovale (PFO). A
PFO is a persistent, one-way, usually flap-like opening in the wall
between the right atrium (RA) and left atrium (LA) of the heart.
Because left atrial pressure is normally higher than right atrial
pressure, the flap usually stays closed. Under certain conditions,
however, right atrial pressure can exceed left atrial pressure,
which creates the possibility that blood could pass from the right
atrium to the left atrium and allow blood clots to enter the
systemic circulation. It is desirable to avoid this situation.
SUMMARY OF THE INVENTION
[0003] Embodiments of the present invention are directed to devices
for closing septal defects such as PFOs, and for delivering and
recovering closure devices. The closure devices in these
embodiments generally include a proximal anchor, a distal anchor,
and a flexible anchor connector for connecting the two anchors. The
connector is preferably a flexible elastomeric layer, which can
also be used to promote tissue ingrowth or for drug delivery. The
flexible material can also be covered with a biocompatible glue to
promote adherence to tissue or growth factors to accelerate tissue
ingrowth.
[0004] In accordance with some embodiments of the invention,
options are provided for multiple delivery/recovery of the same
device without withdrawing the device from the delivery sheath or
otherwise replacing it. Other embodiments include the use of a
single use delivery/recovery string that reduces the complexity of
the delivery/recovery system and the procedure itself.
[0005] These and other features will become apparent from the
following detailed description and drawings. The inventions are
capable of other and different embodiments and its several details
may be capable of modifications in various respects, all without
departing from the invention. Accordingly, the drawings and
description are to be regarded as illustrative in nature and not in
a restrictive or limiting sense.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a closure device according
to a first embodiment.
[0007] FIGS. 2-7 are partial side and partial cross-sectional views
showing the delivery and recovery of a closure device of the type
shown in FIG. 1.
[0008] FIGS. 8-11 are partial side and partial cross-sectional
views of the removal of a closure device according to a second
embodiment of the present invention.
[0009] FIG. 12 is a perspective view of a device according to a
third embodiment of the present invention.
[0010] FIGS. 13-17 are partial side and partial cross-sectional
views of a device and steps for delivering and removing the device
of FIG. 12.
[0011] FIG. 18 is a perspective view of a device according to a
fourth embodiment of the present invention.
[0012] FIGS. 19-22 are partial side and partial cross-sectional
views of a device and steps for delivering and recovering the
device of FIG. 18.
[0013] FIG. 23 is a perspective view of a device according to a
fifth embodiment of the present invention.
[0014] FIGS. 24-28 are partial side and partial cross-sectional
views of the device of FIG. 23 and steps for recovering it.
[0015] FIGS. 29-34 are a perspective view of a sixth embodiment and
partial side and cross-sectional views of the device of FIG. 29 and
its delivery and recovery.
[0016] FIGS. 35-37 are perspective views of further embodiments of
devices according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] This invention relates to structures of the type shown in
application Ser. No. 10/326,535, filed Dec. 19, 2002, published
application no. 2003/0191495, which is expressly incorporated
herein by reference. This invention includes further embodiments of
the device, and methods to allow a physician or other practitioner
to deliver and deploy the device in a defect, then recover and
remove it if desired from a defect after deployment. Some
embodiments allow for multiple deployments and removals of the same
occluder. Other embodiments have a single delivery/recovery
mechanism requiring a simpler delivery/recovery system. While
described for use with a patent foramen ovale (PFO), these systems
and methods could be used for occluding or holding together other
defects.
[0018] As shown in FIG. 1, a closure device 10 has a distal anchor
12 for placement on the left atrial side of a PFO, a proximal
anchor 14 for placement in the right atrial side of a PFO, a
proximal attachment point 16 spaced from anchor 14 for attachment
and release from a wire through a catheter on an anchor connector
22 for connecting anchors 12 and 14, and frangible attachment
points 18, 20 on anchor 14. A bore 24 is provided along the
lengthwise direction in proximal anchor 14. A string 26 extends
from attachment point 18 on anchor 14 attachment point 16 to
attachment point 20 on anchor 14. The string then runs through bore
24 to the end of anchor 14, and across to a permanent attachment
point 28 on anchor 12. Within bore 24, the string can move relative
to anchor 14.
[0019] In this embodiment and others, the distal anchor, the
proximal anchor, and the connectors between the anchor members can
each be made of a bioresorbable material. These components can be
fabricated from a single piece of a bioresorbable polymer or by a
laminated composite of two or more materials to provide a mix of
properties; for example, anchors can have stiff centers and
flexible edges, and blood contacting surfaces can have controlled
porosity or surface texture to promote fast and thorough
endothelialization, while minimizing thrombosis. In addition, the
tissue contacting surface of the anchors can be designed to provide
added stability, such as being roughened. Other components, such as
connection balls and strings, can also be made of bioresorbable
materials; e.g., the string can be made of bioresorbable fibers
that are braided or otherwise combined for strength.
[0020] The anchors are elongated supports, preferably generally
cylindrical with rod-like bodies with ends that are atraumatic, and
preferably rounded. In size, the distal anchor component could be
about 15-30 mm long and 2 mm in diameter with a circular
cross-section. The proximal anchor can have similar dimensions and
shape, although it can be shorter in overall length. Other distal
and proximal anchor structures are also possible. For example,
sides of the anchors can be flattened, especially the side which
will contact the atrial septum. The generally cylindrical shape for
the anchors means that they have at least some portions with
generally round cross-sections, but could have one or more
flattened sides, cut-outs, or other variations from an "ideal"
cylinder.
[0021] The anchor connector can be elastomeric and resilient and
made from a material, such as polyester, biological tissue,
bioresorbable polymer, small diameter springs (e.g., Nitinol), or
spongy polymeric material, and can include thrombogenic or
inflammatory materials. Alternatively, the anchor connector can be
made of multiple strands of material such as polymer fibers. The
anchor connector can be textured or porous. These kinds of surfaces
can also produce inflammatory responses, and therefore can promote
faster tissue ingrowth and faster defect closure.
[0022] FIGS. 2-4 show the delivery of device 10 to a PFO. Device 10
is shown inside a delivery sheath 30, and represented as delivered
in phantom with anchors 12' and 14' and anchor connector 22'. While
in the delivery sheath, the string between the anchors has some
slack in it. The delivery sheath is introduced so that anchor 12 is
positioned in the left atrium 32. This positioning is typically
done by providing delivery sheath 30 in or at the edge of left
atrium 32 through PFO tunnel 34, and retracting sheath 30 so that
anchor 12 is deployed in left atrium 32 against septum primum 38
and septum secundum 39. Sheath 30 is retracted until anchor 14 is
deployed in right atrium 36 as indicated in FIG. 2 in phantom.
FIGS. 3 and 4 show a side view and a top view of device 10 in PFO
tunnel 34. A catheter 40 is maintained in contact with attachment
point 16.
[0023] FIGS. 5-7 show how device 10 can be retrieved as described,
such as if the practitioner determines that it is not sitting
properly. As shown in FIG. 5, delivery sheath 30 is placed up close
to anchor 14 while catheter 40 connected to attachment point 16 is
pulled. As also shown in FIG. 6, the portion 42 of string 26
connected to attachment point 18 breaks, leaving a loose strand of
string. The string also pulls attachment point 20 from anchor 14,
but continues to extend through bore 24 of anchor 14 and be rigidly
attached to anchor 12. Continued pulling on catheter 40 continues
to pull string 26 and causes anchor 12 to rotate as shown to move
from a position where it is generally perpendicular to the
lengthwise direction of delivery sheath 30 to a sufficient angle
where it can be drawn within sheath 30. This pulling action also
reduces the length of string between anchors 14 and 12 until they
are close to each other or in actual contact. This causes anchor 12
to rotate as shown in a direction opposite to that of anchor 14.
Anchor 12 and anchor connector 22 are pulled through the PFO tunnel
and back into sheath 30.
[0024] In this embodiment, because some of the attachment points
have been broken, the device can be retrieved once, but would
typically not be redeployed in this form. This embodiment does
provide the ability to deliver and retrieve the device using one
string and one wire.
[0025] FIGS. 8-11 illustrate another embodiment with a device 80
including distal anchor 82 and proximal anchor 84. A string 86
extends from a rigid attachment point 88 on anchor 84 located at
about a midpoint along the lengthwise direction of anchor 84, and
extends through a loop (or hook) 90 in a delivery catheter 92
within a sheath 94 from this loop, the string extends to an end of
anchor 84, through a lengthwise bore 96 and across a PFO tunnel to
a rigid attachment point 98 at anchor 82. Loop 90 is movable from a
locked position in which the string is held rigidly, to an unlocked
position in which the string can move freely. Control for the loop
is provided to the operator, e.g., by pulling one end of the loop
until the looping wire is fully withdrawn. In this embodiment, with
the loop in the locked position, the delivery process is
substantially the same as that shown in the embodiment in
connection with FIGS. 2-4.
[0026] To retrieve device 80, loop 90 is unlocked from its locked
delivery position, and delivery catheter 92 is withdrawn. This
motion pulls on string 86 and hence anchor 84. Because the distance
to attachment point 88 is shorter than the distance to the end of
anchor 84, this pulling causes the string lengths to equalize and
anchor 84 to rotate. The length of string between anchors 84 and 82
is reduced until anchor 82 rotates in a direction opposite to that
of anchor 84 so that the anchors are end to end and can be
withdrawn into sheath 94.
[0027] This embodiment is useful for recovering the device and can
be redelivered. Only one connection to the device is needed.
[0028] FIGS. 12-17 show yet another embodiment with a device 120.
Referring particularly to FIGS. 12 and. 13, distal anchor 122 is
similar to that in the prior embodiments and has a rigid attachment
point 126 at one end. Proximal anchor 124 for the right atrium is
also elongated and generally cylindrical, but it has a cut out to
form a flat axial face 128 over a portion of the length at one end,
and a flat radial face 130. The cutout provides a smaller profile
than without the cutout.
[0029] A passage 132 extends along a diameter of anchor 124 with a
first ball 134 and a second ball 136 at either end of passage 132
and connected with a string. Ball 136 is slightly larger in
diameter than passage 132, but is small enough that ball 134 can be
pulled through passage 132 when sufficient force is exerted on it.
The ball may deform in the process. An attachment ball 138 is
coupled to ball 136 to provide an attachment point for the
operator.
[0030] These balls can provide distinct functions, such as ball 138
serving as a coupling, and ball 134 serving as a stop. While the
contact points and stops are described in this embodiment and in
other embodiments as balls and while they are preferably spherical
in some embodiments, they can have any shape suitable to form a
coupling to a wire in conjunction with a holder that can push or
pull them, or a stop, or some other connector. These couplings can
be formed differently within one device when there are several
couplings; for example, a spherical ball that can be gripped with a
grappling hook could be used in one case for a coupling, and a
hemispheric piece could be used as a stop.
[0031] Referring to FIGS. 14-17, the device is shown in a deployed
position (FIG. 14) from which it can be retrieved. A wire 140 in a
delivery sheath 142 is connected to ball 138 for attachment. As
shown in FIG. 15, the pulling force represented by arrow 144 pulls
ball 134 through passage 132. After ball 134 is clear of passage
132, sheath 142 is drawn back. Further pulling force causes anchor
124 to rotate and anchor 122 to rotate in a direction opposite to
that of anchor 124. As shown in FIG. 17, device 120 can be pulled
back fully into sheath 142.
[0032] FIG. 18 shows another embodiment of a device 180 with
anchors 182 and 184, and with a single ball 186 serving as a
connector and a stop on the inner side of a radial passage 188. A
string 190 extends to one end of anchor 184, through a lengthwise
passage 192, across to anchor 182 (through a PFO tunnel when
deployed), through a lengthwise passage 194 in anchor 182, and to a
rigid connection with ball 186. Two string ends extend away from
the device and are used to control the device, but with ball 186,
the string forms an unbroken loop with two ends.
[0033] FIG. 19 shows device 180 loaded in a sheath 198 and ready
for delivery. A delivery catheter 200 within sheath 198 provides an
inward force to one end of the anchor. The delivery sheath would
typically be positioned in the left atrium and retracted to allow
anchor 182 to be released within the left atrium. Then, sheath 198
would be withdrawn into the right atrium and further pulled back to
release anchor 184 within the right atrium. The resulting deployed
device 180 is shown in FIG. 20. After a successful deployment, the
strings can be cut.
[0034] Referring to FIGS. 20-22, to recover device 180, a force is
applied to lower end 202 of string 190 in order to rotate anchor
184, causing anchor 182 to rotate in a direction opposite to that
of anchor 184 and be returned into sheath 198.
[0035] In this embodiment, the device can be redeployed if desired.
From FIG. 22, by pulling on upper string 204, ball 186 is moved
back against anchor 184 at passage 188 as shown by 186'. At that
point. FIG. 22 is substantially similar to FIG. 19, which shows
device 180 ready to be deployed.
[0036] Referring to FIG. 23, a device 230 has a right atrial anchor
234 with a portion cut out of a generally cylindrical side by
making a radial cut part way into the anchor and an axial cut along
part of the lengthwise direction, with the cuts at right angles to
form a cutout section. The resulting faces are similar to those in
the device of FIG. 12. In this case, a first ball 236 is connected
with a string 238 to the flat axial face that is formed by the
radial cut, while a second ball 240 is attached with a string 242
that extends through a lengthwise bore 244 in anchor 234. That
string further extends to anchor 232 where there is a rigid
attachment at one end. At the other end of left atrial anchor 232
is an enlarged diameter portion 246.
[0037] Referring to FIG. 24, when device 230 is loaded in a
delivery sheath 250 for delivery, increased diameter portion 246 of
anchor 232 is larger than the opening of a delivery catheter 252
and is at the innermost distal end of catheter 252. The string
portion 254 between the anchors is shown with some slack, and upper
and lower wires 256,258 are connected to respective attachment
balls 236,240.
[0038] The device is delivered in a similar manner to those
described above to a deployed position as shown in FIG. 25. The
wires may provide enough stiffness to keep device 230 in place as
catheter 252 is removed, or an additional mandrel or catheter (not
shown) can be positioned against device 230 to prevent the device
from moving toward the proximal end as the sheath is withdrawn
toward the proximal end.
[0039] FIGS. 26-28 show the retrieval process for device 230. In
this case, lower wire 258 is pulled to cause anchor 234 to rotate.
In FIG. 27, the upper wire is pulled to reintroduce slack 254 (FIG.
28). The upper wire is released to allow the device to assume the
configuration of FIG. 24. Note that in this position, it can be
redeployed into the PFO.
[0040] FIG. 29 shows another device 290 which has similarities with
the embodiment of FIG. 23, with one ball 296 attached to a face 298
formed by the partial radial cut, but with another ball 300
attached to an end of anchor 294. In this embodiment, unlike a
number of others, there is no lengthwise bore through either
anchor. Anchors 292 and 294 are attached with permanent attachment
points with a string 304 at the same end of each anchor, and
therefore there is slack that would not be taken up by the
operator.
[0041] Referring to FIG. 30, device 290 is shown in a sheath 306
and ready for delivery. As indicated above, wires 308 and 310
against respective balls 296 and 300 may be able to provide
sufficient resistance to keep the device from being withdrawn as
sheath 306 is withdrawn around device 290. If not, an additional
device can be inserted to hold device 290 in place as sheath 306 is
withdrawn. Device 290 is thus employed in a manner similar to that
described above, with the sheath provided in the left atrium, or
withdrawn to allow anchor 292 to be positioned, and then further
withdrawn into the right atrium to allow anchor 294 to be
positioned.
[0042] FIGS. 31-34 show the device being retracted into a delivery
sheath by pulling on the lowermost wire that is connected to the
ball attached at the end of the right atrial anchor. In this
embodiment, both anchors rotate in opposite directions until they
are end-to-end and drawn into the delivery sheath. From the
position in FIG. 34, the device could be redeployed.
[0043] FIG. 35 shows another embodiment of a device 350, similar to
that shown in FIG. 29, except that the string connecting the
anchors extends from one end of one anchor to an opposite end of
the other anchor, thereby extending across the anchor connector.
This string connection helps to pull anchor 352 so that it rotates
in a direct opposite to the rotation of anchor 354.
[0044] Referring to FIG. 36, in another embodiment, a device 360
has distal anchor 362 and proximal anchor 364 connected together by
strings 365 and 366, both of which pass through a loop 367. Anchor
364 also has balls 368 and 369 serving as connection points. In
this case, retrieving the device includes providing a connection to
ball 369 and pulling to rotate anchor 364, with continued pulling
causing rotation of anchor 362. This device would thus be deployed
and retrieved in a manner similar to those described above, and
could be redeployed multiple times.
[0045] Referring to FIG. 37, a device 370 has a distal anchor 372
and a proximal anchor 374. It also has attachment balls that are
similar to those shown in FIG. 36, namely one at one end and one in
the middle of the anchor. Distal anchor 372 has strings 375 and 376
extending from each end. String 375 extends from one end of anchor
372, through a loop.
[0046] 377 that is connected to anchor 374, through a loop 378
connected with a string 376 to another end of anchor 372 and then
to the opposite end of anchor 374. String 375 can also have small
strings attached to it, referred to here as whiskers 380. These
could be provided by being glued to the string, or if the string is
in a braided form, the string can be intentionally frayed. The
whiskers can help provide some inflammatory effect between tissues,
such as between the tissue flaps of a PFO to encourage tissue
ingrowth. The device can be delivered and redeployed in a manner
similar to that described above.
[0047] The closure devices described here can optionally be used
along with suturing or stapling techniques deployed from the
catheter or sheath.
[0048] The devices can use radiopaque fillers or marker bands
fabricated from noble metals such as platinum or gold to allow
x-ray visualization. These markers can be attached using a variety
of common methods, such as adhesive bonding, lamination between two
layers of polymer, or vapor deposition where the anchors of the
devices can be sewn or stapled to septum primum or secundum for
better dislodgment resistance. Also, in some embodiments, an anchor
connector can, if desired, be covered with biocompatible glue to
adhere to the tissue or can be loaded or coated with drugs or
growth factors to promote healing The glue and also certain drugs
can be stored in any cavities in the anchors and released after
deployment.
[0049] The anchor connector can be mounted to allow the proximal
anchor to slide relative to the connector. A biasing spring (not
shown), which may be an expandable coil spring, can be formed at an
outer end of the central connector to bias the proximal anchor
toward the distal anchor when both are.
[0050] The various closure devices described herein can include a
number of advantageous features. The closure devices preferably
have an atraumatic shape to reduce trauma during deployment or
removal. In addition, the devices can be self-orienting for ease of
deployment. Furthermore, because of the flexible anchor connector,
the devices generally conform to the anatomy instead of the anatomy
conforming to the devices, which is especially useful in long
tunnel defects. The devices also generally have a relatively small
profile within the heart after deployment. The flexible anchor
connector of the devices can encourage faster tissue ingrowth, and
thus faster defect closure. Furthermore, there are generally no
exposed thrombogenic components on the left and right atrial sides.
The devices can also advantageously include bioresorbable
components, which can disappear over time.
[0051] Other benefits of the devices can include possible use of a
relatively small diameter delivery sheath, use of reduced or no
metal mass in the device, ease of manufacturing, cost
effectiveness, and overall design simplicity.
[0052] Having described embodiments, it should be apparent that
modifications can be made without departing from the scope of the
invention. For example, while the anchors are shown generally as
straight and elongated, they could be curved.
* * * * *