U.S. patent application number 12/791410 was filed with the patent office on 2010-09-16 for patent foramen ovale closure system.
This patent application is currently assigned to EV3 ENDOVASCULAR, INC.. Invention is credited to Andrew G.C. Frazier, Alexander K. Khairkhahan, Alan R. Klenk, Chad C. Roue, Erik J. van der Burg.
Application Number | 20100234885 12/791410 |
Document ID | / |
Family ID | 32850966 |
Filed Date | 2010-09-16 |
United States Patent
Application |
20100234885 |
Kind Code |
A1 |
Frazier; Andrew G.C. ; et
al. |
September 16, 2010 |
PATENT FORAMEN OVALE CLOSURE SYSTEM
Abstract
A patent foramen ovale closure device, method of delivering and
a delivery system are provided. The device may include a closure
device releasably connectable to an actuator. The device may
include a proximal segment, an intermediate segment and a distal
segment. When delivered, the proximal segment and intermediate
segment form a first clip-shaped portion sized and configured to be
positioned over a septum secundum of the patent foramen ovale, and
the intermediate segment and distal segment form a second
clip-shaped portion sized and configured to be positioned over a
septum primum of the patent foramen ovale.
Inventors: |
Frazier; Andrew G.C.;
(Sunnyvale, CA) ; Klenk; Alan R.; (San Jose,
CA) ; Khairkhahan; Alexander K.; (Palo Alto, CA)
; Roue; Chad C.; (Fremont, CA) ; van der Burg;
Erik J.; (Los Gatos, CA) |
Correspondence
Address: |
KNOBBE, MARTENS, OLSON & BEAR, LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
EV3 ENDOVASCULAR, INC.
Plymouth
MN
|
Family ID: |
32850966 |
Appl. No.: |
12/791410 |
Filed: |
June 1, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10771845 |
Feb 4, 2004 |
|
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12791410 |
|
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|
60445088 |
Feb 4, 2003 |
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Current U.S.
Class: |
606/213 |
Current CPC
Class: |
A61B 2017/00592
20130101; A61B 2017/00619 20130101; A61B 17/0057 20130101; A61B
17/00491 20130101; A61B 2017/00243 20130101; A61B 17/12122
20130101; A61B 2017/00579 20130101; A61B 17/12113 20130101; A61B
2017/00575 20130101; A61B 2017/00623 20130101; A61B 2017/00606
20130101; A61B 17/12172 20130101; A61B 17/064 20130101; A61B
2017/00557 20130101; A61B 2017/0649 20130101; A61B 17/1219
20130101 |
Class at
Publication: |
606/213 |
International
Class: |
A61B 17/08 20060101
A61B017/08 |
Claims
1-7. (canceled)
8. A system for closing a patent foramen ovale with an overlapping
septum primum and a septum secundum, comprising: a delivery
catheter having a lumen extending therethrough; a closure device
configured for being configured for placement in the opening in the
heart and for collapsible containment within the lumen, the closure
device comprising: a wire; an anterior section; a posterior
section; at least one loop; at least one wing configured to anchor
the device into heart tissue; and a tether extending through the at
least one loop, the tether configured to releasably retain the
closure device with the delivery catheter.
9. The system for closing a patent foramen ovale of claim 8,
wherein the tether extends through the lumen and is detachable from
the at least one loop.
10. The system for closing a patent foramen ovale of claim 8,
wherein the closure device is self-expandable.
11. The system for closing a patent foramen ovale of claim 8,
wherein the wire, anterior section, posterior section and at least
one loop are integral.
12. The system for closing a patent foramen ovale of claim 8,
wherein the wire comprises Nitinol.
13. The system for closing a patent foramen ovale of claim 8,
wherein the wire comprises stainless steel.
14. The system for closing a patent foramen ovale of claim 8, the
wings extending beyond the overlapping septum primum and a septum
secundum of the patent foramen ovale to provide additional support
to closure device.
15. The system for closing a patent foramen ovale of claim 8,
further comprising a material attached to the closure device
configured to facilitate cellular in-growth.
16. A system for closing a defect in a human heart, comprising: a
wire frame having expandable anterior and posterior sections,
wherein the wire frame is biased to be expanded such that the
anterior and posterior sections engage tissue on opposite sides of
the defect, and the wire frame is configured to be retrieved by
collapsing the wire frame; at least one loop in the anterior
section of the wire frame; at least one wing configured to anchor
the device into heart tissue; and a tether passing through the at
least one loop; and a delivery catheter having a lumen for
delivering the wire frame in a collapsed configuration to the
defect.
17. The system of claim 16, wherein the posterior section includes
a plurality of loops extending radially outwardly.
18. The system of claim 16, further comprising a material on at
least a portion of the wire frame configured to promote tissue
growth.
19. The system of claim 18, wherein the material is formed of a
relatively porous material for permitting ingrowth of collagen or
fibrous tissue into the material.
20. The system of claim 16, comprising a plurality of loops in the
anterior section of the wire frame and a plurality of tethers
passing through the loops.
21. A tissue opening occluder for placement in an area formed by
overlapping atrial septa of a patent foramen ovale (PFO), the
overlapping atrial septa forming a PFO tunnel, the PFO tunnel
having a generally planar geometry along a length of the tunnel
from the left atrium to the right atrium, the tissue opening
occluder comprising: a planar support structure sized and
configured to be deployed into position within the PFO tunnel
between the overlapping atrial septa with a planar portion of the
planar support structure configured to be generally parallel with a
tissue wall extending along a length of the PFO tunnel from the
left atrium to the right atrium, the planar portion comprising a
first substantially planar tissue engaging side and a second
substantially planar tissue engaging side, the planar portion
having a flat configuration defined between the first and second
substantially planar tissue engaging sides; at least one wing
configured to anchor the device into heart tissue; and a material
supported by the planar support structure and sized and configured
to be positioned within the PFO tunnel between the overlapping
atrial septa, the material promoting tissue growth to anchor the
occluder in intimate contact with a tissue wall.
22. The tissue opening occluder of claim 21, wherein the material
is porous.
23. The tissue opening occluder of claim 21, wherein the support
structure is made of metal wire.
24. The tissue opening occluder of claim 21, wherein the planar
support structure further comprises at least one loop selectively
attachable to a tether.
25. The tissue opening occluder of claim 21, wherein the planar
support structure further comprises wings configured to anchor the
support structure into heart tissue.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of co-pending U.S. patent
application Ser. No. 10/771,845, filed on Feb. 4, 2004, which
claims the benefit of U.S. Provisional Application No. 60/445,088,
filed Feb. 4, 2003, the entirety of which is hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention relate to methods and
devices for closing a body lumen or cavity and, in particular, for
closing a patent foramen ovale.
[0004] 2. Description of the Related Art
[0005] Embolic stroke is the nation's third leading killer for
adults, and is a major cause of disability. There are over 700,000
strokes per year in the United States alone. Of these, roughly
100,000 are hemorrhagic, and 600,000 are ischemic (either due to
vessel narrowing or to embolism). About 50,000 of the ischemic
strokes are believed to be caused by a patent foramen ovale.
However, the risk of recurrent stroke is higher in patients whose
strokes are caused by a patent foramen ovale.
[0006] Pharmacological therapies for stroke prevention such as oral
or systemic administration of warfarin or the like have been
inadequate due to serious side effects of the medications and lack
of patient compliance in taking the medication.
[0007] In general, the heart is divided into four chambers, the two
upper being the left and right atria and the two lower being the
left and right ventricles. The atria are separated from each other
by a muscular wall, the interatrial septum, and the ventricles by
the interventricular septum.
[0008] Either congenitally or by acquisition, abnormal openings,
holes or shunts can occur between the chambers of the heart or the
great vessels (interatrial and interventricular septal defects or
patent ductus arteriosus and aortico-pulmonary window
respectively), causing shunting of blood through the opening. A
patent foramen ovale is a condition wherein an abnormal opening is
present in the septal wall between the two atria of the heart.
Blood can flow directly between these two atria, compromising the
normal flow of blood and efficiency of the patient's heart. The
deformity is usually congenital, resulting from a failure of
completion of the formation of the septum, or wall, between the two
sides during fetal life when the heart forms from a folded tube
into a four-chambered, two unit system.
[0009] In contrast to other septal defects which tend to have a
generally longitudinal axis, a patent foramen ovale tends to behave
like a flap valve. Accordingly, the axis of the patent foramen
ovale tends to be at an angle, and almost parallel to the septal
wall.
[0010] These deformities can carry significant sequelae. For
example, with a patent foramen ovale, blood is shunted from the
left atrium of the heart to the right, producing an over-load of
the right heart. In addition to left-to-right shunts such as also
occur in patent foramen ovale, the left side of the heart has to
work harder because some of the blood which it pumps will
recirculate through the lungs instead of going out to the rest of
the body. The ill effects of these defects usually cause added
strain on the heart with ultimate failure if not corrected.
[0011] Previously, patent foramen ovale have required relatively
extensive surgical techniques for correction. To date the most
common method for closing intracardiac shunts, such as a patent
foramen ovale, entails the relatively drastic technique of
open-heart surgery, requiring opening the chest or sternum and
diverting the blood from the heart with the use of a
cardiopulmonary bypass. The heart is then opened, the defect is
sewn shut by direct suturing with or without a patch of synthetic
material (usually of Dacron, Teflon, silk, nylon or pericardium),
and then the heart is closed. The patient is then taken off the
cardiopulmonary bypass machine, and the chest is closed.
[0012] In place of direct suturing, closures of a patent foramen
ovale by means of a mechanical prosthesis have also been disclosed.
A number of these devices, designed for closures of interauricular
septal defects, have been used to correct patent foramen ovale.
[0013] Although these devices have been known to effectively close
other septal defects, there are few closure devices which have been
developed specifically for closing patent foramen ovale. Although
these devices have been effective in some cases, there is still
much room for improvement.
[0014] Notwithstanding the foregoing, there remains a need for a
method and improved apparatus for correcting patent foramen
ovale.
SUMMARY OF THE INVENTION
[0015] Embodiments of the present invention provide a minimally
invasive closure device for closing a patent foramen ovale.
Improved delivery and positioning systems are also provided.
[0016] In accordance with one embodiment, a closure device for
closing a patent foramen ovale is provided. The device includes a
proximal end, a distal end, a proximal segment, an intermediate
segment, and a distal segment, wherein each of the segments is
sequentially aligned. The device has a generally elongate
configuration and a clip configuration. When the device is in its
elongate configuration, the proximal and distal ends are pulled
away from each other such that the proximal segment, intermediate
segment, and distal segment become relatively more linear. When the
device is in its clip configuration, the proximal segment and
intermediate segment are drawn into a first clip-shaped portion
sized and configured to be positioned over a septum secundum of the
patent foramen ovale. The intermediate segment and distal segment
are drawn into a second clip-shaped portion sized and configured to
be positioned over a septum primum of the patent foramen ovale. The
first clip-shaped portion and the second clip-shaped portion
provide a force against the septum primum and septum secundum to
pinch the two relatively closer together.
[0017] In one embodiment, the closure device may be formed from a
wire structure, more preferably one integral wire. In one
embodiment, the proximal and distal segments are identical in
shape, and may have identical shapes that form mirror images of
each other across the patent foramen ovale to equally apply
compressive force to both sides of the patent foramen ovale. In
another embodiment, the proximal segment has a larger dimension
than the distal segment, and more preferably has both a greater
length and width than the distal segment. The distal segment may
include a pair of wings adapted to extend over the tip of the
septum primum. The device may also include loops, eyelets or other
structure adapted for releasable engagement with a delivery system,
as described below. The device may also include anchors or other
tissue engaging structures to facilitate securement of the device
in the patent foramen ovale.
[0018] In accordance with another embodiment, a closure device for
closing a patent foramen ovale is provided. The device includes a
proximal segment, a distal segment, and an intermediate segment
which may be integrally formed, preferably from an integral wire
structure. A covering, sleeve or laminate structure is provided on
at least one of the segments of the device. In one embodiment, a
sleeve is provided over the intermediate segment and is adapted to
be positioned in the tunnel of the patent foramen ovale. In another
embodiment a laminate structure may be provided over at least the
proximal or anterior portion. The sleeve may be made of a material
that facilitates cellular in-growth, such as ePTFE.
[0019] In accordance with one embodiment, a method of closing a
patent foramen ovale having a septum primum and a septum secundum
is provided. The method includes providing a closure device having
a proximal end and a distal end and having a generally elongate
configuration and a clip configuration. When the device is in its
elongate configuration, the proximal and distal ends are pulled
away from each other, and when the device is in its clip
configuration the device has generally an S-shape. The device is
releasably attached relative to a delivery device. The device is
then delivered to the patent foramen ovale with the delivery
device, the closure device being held relative to the delivery
device in its elongate configuration. The closure device is
deployed in the patent foramen ovale, such that the device when
deployed includes a first clip-shaped portion positioned around the
septum secundum and a second clip-shaped portion positioned around
the septum primum.
[0020] In accordance with a further embodiment, a method of closing
a patent foramen ovale having a septum primum and a septum secundum
in provided. The method includes providing a closure device having
a proximal end, a distal end, a proximal segment, an intermediate
segment and a distal segment. The method further includes deploying
the closure device within the patent foramen ovale such that the
distal segment lies along a surface of the septum primum within the
left atrium of the patient. The proximal segment preferably lies
along a surface of the septum secundum within the right atrium of
the patient. The intermediate segment preferably lies in a channel
or tunnel between the septum primum and the septum secundum. When
the closure device is deployed, it exerts a force between the
proximal segment and intermediate segment and between the
intermediate segment and distal segment to draw or pinch the septum
primum and septum secundum together.
[0021] In accordance with another embodiment, a method of closing a
patent foramen ovale is provided. The method includes positioning a
closure device at a patent foramen ovale and deploying the closure
device, such that the septum primum and septum secundum are secured
together by the closure device.
[0022] In a preferred delivery method, the closure device is
self-expanding and may be releasably engaged with a percutaneous
delivery device. In one embodiment, where the closure device has
proximal, intermediate and distal segments, each of the segments is
releasably engaged with the delivery device, such as by extending a
core or guidewire through eyelets formed in each of the segments of
the device. In another embodiment, the closure device may be
internally or externally threaded to releasably engage a
corresponding delivery device. This threading may be provided at
the proximal end of the device, at the distal end of the device, or
may be provided in proximal, intermediate and/or distal segments.
The closure device may be delivered through an outer deployment
catheter which guides the device to the patent foramen ovale.
[0023] In accordance with one embodiment, a closure device for
closing a patent foramen ovale is provided. The device includes a
proximal segment and a distal segment which may be integrally
formed. The device generally has a hook configuration, wherein the
distal segment is sized and configured to be positioned over a
septum primum of the patent foramen ovale. The proximal segment is
sized and configured to extend through the tunnel of the patent
foramen ovale, and at its proximal end, may increase in width to
form wings to secure the closure device in place. In this
configuration, the proximal segment is sized and configured to be
positioned along a surface of the septum of the patent foramen
ovale in the right atrium. The device may also include a sleeve or
laminate structure between the proximal end and the distal segment,
the sleeve or laminate structure adapted to be positioned in the
patent foramen ovale tunnel. The sleeve or laminate structure is
made of material adapted to facilitate cellular in-growth, such as
ePTFE.
[0024] In accordance with a further embodiment, a method of closing
a patent foramen ovale is provided. The method includes positioning
a closure device at a patent foramen ovale and deploying the
closure device, such that the septum primum is secured by the
closure device. In one embodiment, only the septum primum is
secured by the closure device, with the device forming a hook over
the tip of the septum primum to hold the septum primum in place.
Preferably, the closure device may have wings in a proximal segment
thereof that extend beyond the width of the tunnel of the patent
foramen ovale. The wings as delivered are positioned in the right
atrium against a surface of the septum primum.
[0025] In another embodiment, delivery systems incorporating the
devices used in the delivery methods are provided. According to one
delivery system, a deployment catheter having a proximal end and a
distal end is provided. An actuator extends through the deployment
catheter. A closure device is releasably attached to the actuator.
The actuator is adapted to advance the closure device from the
distal end of the deployment catheter and position a distal segment
of the closure device over a septum primum of the patent foramen
ovale and position a proximal segment of the closure device over a
septum secundum of the patent foramen ovale. The closure device is
actuatable to pinch together the septum primum and septum secundum
once delivered, and may be self-expanding and/or manually actuated.
It will also be appreciated that the closure device can be
delivered without the deployment catheter, such that the closure
device is releasably secured and released from the actuator to
deliver the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an anterior illustration of a heart, with the
proximal parts of the great vessels.
[0027] FIG. 2A is a perspective view of a closure device in
accordance with one embodiment the present invention.
[0028] FIG. 2B is a perspective view of a closure device in
accordance with one embodiment of the present invention in a
delivery state.
[0029] FIG. 3 is a side elevational view of the closure device
shown in FIG. 2A.
[0030] FIG. 4 is a cross-sectional view of one of the segments of
the closure device shown in FIG. 2A.
[0031] FIG. 4A is an enlarged view of a portion of the segment of
FIG. 4.
[0032] FIG. 5 is a cross-sectional view of a patent foramen ovale
closed with the closure device of FIG. 2A, shown schematically.
[0033] FIG. 6 is a perspective view of the closure device of FIG.
2A in a delivery state.
[0034] FIG. 7 is a perspective view of the closure device of FIG.
2A during a deployment state.
[0035] FIG. 8 is a schematic cross-sectional view through the heart
with a transeptal catheter deployed at a patent foramen ovale.
[0036] FIG. 9 is a cross-sectional view of the catheter of FIG. 8
through line 9-9.
[0037] FIG. 10 is a partial cross-sectional view of an embodiment
of the catheter of FIG. 8, with a closure device being delivered
there through.
[0038] FIG. 11A is a partial cross-sectional view of an embodiment
of the catheter of FIG. 8, with an embodiment of a closure device
illustrated being delivered using a torque rod.
[0039] FIG. 11B is an enlarged view of a connecting portion of the
closure device shown in FIG. 11A.
[0040] FIG. 11C is a partial cross-sectional view of another
embodiment of the catheter of FIG. 8, with another embodiment of a
closure device being delivered there through.
[0041] FIG. 11D is an enlarged view of a distal portion of the
closure device shown in FIG. 11C.
[0042] FIGS. 12A-E are schematic views of a patent foramen ovale
closure procedure in accordance with one embodiment of the present
invention.
[0043] FIG. 13 is a perspective view of a closure device in
accordance with another embodiment of the present invention.
[0044] FIG. 14 is a perspective view of the closure device of FIG.
13 in a delivery state.
[0045] FIG. 15 is a back elevational view of a closure device in
accordance with another embodiment of the present invention.
[0046] FIG. 16 is a side view of the closure device of FIG. 15.
[0047] FIG. 17 is a cross-sectional view of a patent foramen ovale
closed with the closure device of FIG. 15.
[0048] FIGS. 18A-E are schematic views of a patent foramen ovale
closure procedure in accordance with one embodiment of the present
invention.
[0049] FIG. 19A is a front elevational view of a closure device in
accordance with another embodiment of the present invention.
[0050] FIG. 19B is a side elevational view of the closure device
shown in FIG. 19A.
[0051] FIG. 20 is a cross-sectional view of a patent foramen ovale
closed with the closure device of FIG. 19.
[0052] FIGS. 21A-D are schematic views of a patent foramen ovale
closure procedure in accordance with another embodiment of the
present invention.
[0053] FIG. 22A is a back view of a closure device in accordance
with another embodiment of the present invention.
[0054] FIG. 22B is a back view of a closure device in accordance
with another embodiment of the present invention.
[0055] FIG. 22C is a front view of the device of FIG. 22B, showing
a laminated structure attached thereto.
[0056] FIG. 23 is a cross-sectional view of a patent foramen ovale
closed with the closure device of FIG. 22A or FIG. 22B, shown
schematically.
[0057] FIGS. 24A-D are schematic views of a patent foramen ovale
closure procedure in accordance with one embodiment of the present
invention, shown inversely to the deployment orientation to
facilitate explanation.
[0058] FIG. 25 is a side elevational view of a closure device in
accordance with another embodiment of the present invention.
[0059] FIG. 26 is a side elevational view of the closure device of
FIG. 25 having a plurality of retention structures.
[0060] FIG. 27 is a rear elevational view of the closure device of
FIG. 25.
[0061] FIG. 28 is a partial cross-sectional view of a patent
foramen ovale closed with the closure device of FIG. 25.
[0062] FIG. 29 is a front elevational view of the closure device of
FIG. 25 prior to expansion having a pull wire expansion system.
[0063] FIG. 30 is a front elevational view of the closure device of
FIG. 25 after expansion having a pull wire expansion system.
[0064] FIG. 31 is a front elevational view of the closure device of
FIG. 25 prior to expansion having a twisting expansion system.
[0065] FIG. 32 is a front elevational view of the closure device of
FIG. 25 after expansion having a twisting expansion system.
[0066] FIG. 33 is a schematic side view of a closure device in
accordance with another embodiment of the present invention.
[0067] FIG. 34 is an end view of the closure device of FIG. 33.
[0068] FIG. 35 is a side view of a closure device in accordance
with another embodiment of the present invention.
[0069] FIG. 36 is an end view of the closure device of FIG. 35.
[0070] FIG. 37 is a side view of a closure device in accordance
with another embodiment of the present invention.
[0071] FIGS. 38A-B are side schematic views showing the expansion
of the closure device of FIG. 37.
[0072] FIG. 39 is a side view of a closure device in accordance
with another embodiment of the present invention.
[0073] FIG. 40 is an end view of the closure device of FIG. 39.
[0074] FIG. 41 is a side view of the closure device of FIG. 39 in a
collapsed state.
[0075] FIG. 42 is a side view of a closure device in accordance
with another embodiment of the present invention.
[0076] FIG. 43 is an end view of the closure device of FIG. 42.
[0077] FIGS. 44A-C are schematic views of a defect closure
procedure in accordance with one embodiment of the present
invention.
[0078] FIG. 45 is a side view of the closure device of FIG. 42 in a
collapsed state.
[0079] FIG. 46 is a perspective view of a closure device in
accordance with another embodiment of the present invention.
[0080] FIG. 47 is a cross-sectional view of a patent foramen ovale
closed with a closure device in accordance with another embodiment
of the present invention.
[0081] FIG. 48 is a cross-sectional view of a patent foramen ovale
closed with a closure device in accordance with another embodiment
of the present invention.
[0082] FIG. 49 is a side elevational view of a closure device in
accordance with another embodiment of the present invention.
[0083] FIG. 50 is a front view of the closure device of FIG.
49.
[0084] FIG. 51 is a cross-sectional view of a patent foramen ovale
closed with the closure device of FIG. 40.
[0085] FIG. 52 is a perspective view of a closure device in
accordance with another embodiment of the present invention.
[0086] FIG. 53 is a cross-sectional view of a patent foramen ovale
closed with the closure device of FIG. 52.
[0087] FIG. 54 is a perspective view of a closure device in
accordance with another embodiment of the present invention.
[0088] FIG. 55 is an enlarged perspective view of a closure device
in accordance with another embodiment of the present invention.
[0089] FIG. 56 is a side view of the closure device of FIG. 55.
[0090] FIG. 57 is a perspective view of a closure device in
accordance with another embodiment of the present invention.
[0091] FIG. 58 is a cross-sectional view of a patent foramen ovale
closed with the closure device of FIG. 57.
[0092] FIGS. 59A-C are schematic views of a defect closure
procedure in accordance with one embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0093] For simplicity, preferred embodiments of the present
invention will be described primarily in the context of a patent
foramen ovale closure procedure. However, the devices and methods
herein are readily applicable to a wider variety of closure or
attachment procedures, and all such applications are contemplated
by the present inventors. For example, additional heart muscle
procedures such as atrial septal defect closure and patent ductus
arteriosis closure are contemplated. Vascular procedures such as
isolation or repair of aneurysms, anastomosis of vessel to vessel
or vessel to prosthetic tubular graft joints may also be
accomplished using the devices of the embodiments described herein.
Attachment of implantable prostheses, such as attachment of the
annulus of a prosthetic tissue or mechanical heart valve may be
accomplished. A variety of other tissue openings, lumens, hollow
organs and surgically created passageways may be closed. Adaptation
of the devices and methods disclosed herein to accomplish
procedures such as the foregoing will be apparent to those of skill
in the art in view of the disclosure herein.
[0094] Referring to FIG. 1, a heart 100 is illustrated to show
certain portions including the left ventricle 102, the left atrium
104, the left atrial appendage 106, the pulmonary artery 108, the
aorta 110, the right ventricle 112, the right atrium 114, and the
right atrial appendage 116. As is understood in the art, the left
atrium 104 is located above the left ventricle 102 and the two are
separate by the mitral valve (not illustrated).
[0095] First Clip Embodiments
[0096] Referring to FIGS. 2A and 3-7, there is illustrated one
embodiment of an occlusion or closure device 200 sized and
configured to close a patent foramen ovale in accordance with one
embodiment of the present invention. The closure device preferably
comprises a wire shaped to form a clip, which is preferably shaped
like a paperclip. As illustrated, in one embodiment the closure
device can be considered to have generally an S-shape or two
adjacent U-shaped or clip portions, as described further below. The
closure device 200 has a proximal end 202 and a distal end 204. The
designation proximal or distal is not intended to indicate any
particular anatomical orientation or deployment orientation within
the deployment catheter, as described below.
[0097] The closure device 200 generally has three sections: a
proximal segment 206, a distal segment 208, and an intermediate
segment 210. As illustrated in FIG. 4, each of these segments is
preferably generally annular-shaped or oval-shaped forming a loop,
and may be generally parallel to each other when the device 200 is
in its deployment state, shown in FIG. 2A. It will be appreciated
that the segments may have any suitable size and configuration for
closing a patent foramen ovale, including round, oblong,
rectangular, triangular and square. Each of the segments 206, 208,
210 may be formed from wire 212 and may be separately or integrally
formed.
[0098] In one embodiment, the three segments 206, 208, 210 are
sequentially aligned such that a distal end 206b of proximal
segment 206 is connected to a proximal end 210a of intermediate
segment 210, and a distal end 210b of intermediate segment 210 is
connected to a proximal end 208a of distal segment 208. As
illustrated, these segments 206, 208, 210 are connected by
connecting portions 211a and 211b, and may be integrally formed
with the connecting portions. Alternatively, they may be joined
together by any suitable technique. The closure device 200 is also
preferably provided with a detachment element 214 at its proximal
end 202, illustrated as an externally threaded portion.
Alternatively, the proximal end 202 of the device 200 may be
provided with a threaded aperture through which a delivery core is
threadably engaged, a loop or eyelet, or other suitable structure
as will be discussed herein for releasably connecting the device to
a deployment system.
[0099] In one embodiment, a wire 212 is used to form the segments
206, 208 and 210, as well as connecting portions 211, and comprises
a metal such as stainless steel, Nitinol, Elgiloy, or others which
can be determined through routine experimentation by those of skill
in the art. The wire may also be biodegradable. Wires having a
circular or rectangular cross-section may be utilized depending
upon the manufacturing technique. It will be appreciated that the
closure device 200 need not be formed from a wire, and can be an
integral structure, for example, laser cut from a tube or other
stock. It is also envisioned that other non-metallic biocompatible
materials may be used to form wire 212. The wire 212 may be solid
or hollow.
[0100] As shown in FIG. 4A, in one embodiment at least a portion of
the wire 212 is covered with a sleeve 224. The sleeve 224 may
comprise any of a variety of materials which facilitate cellular
in-growth, such as ePTFE. The suitability of alternate materials
for sleeve 224 can be determined through routine experimentation by
those of skill in the art. The sleeve 224 may be provided on either
one or all sections of the closure device. For example, the
intermediate segment 210 alone or the entire device 200 may be
provided with sleeve 224. In one embodiment, the sleeve 224
comprises two layers. The two layers may be bonded to each other
around the wire 212 in any of a variety of ways, such as by heat
bonding with or without an intermediate bonding layer such as
polyethylene or FEP, adhesives, sutures, and other techniques which
will be apparent to those of skill in the art in view of the
disclosure herein. The sleeve 224 in one embodiment preferably is
securely attached to the device 200 and retains a sufficient
porosity to facilitate cellular ingrowth and/or attachment.
[0101] Referring back to FIG. 2A, the device 200 is illustrated in
its deployment state. The device 200 may be self-expanding, having
a remembered shape as illustrated in FIG. 2A. Alternatively, the
device 200 may be mechanically actuated to assume its deployment
state. As illustrated, the device 200 preferably includes a locking
element 228 and retention elements, preferably in the form of
eyelets 230, for retaining the locking element 228 to the closure
device 200. In one embodiment, the eyelets 230 are offset from one
another on adjacent segments of the device. In another embodiment,
the eyelets 230 are in line with the longitudinal axis of the
device 200. Other details regarding a device having eyelets
described above, as well as similar devices, may be found in U.S.
Pat. Nos. 6,214,029, 6,551,344 and 6,440,152, which are hereby
incorporated by reference in its entirety. The locking element 228
is used to longitudinally shorten and radially expand the device.
The locking element 228 preferably comprises a locking string which
is preferably used to both longitudinally shorten and radially
expand and lock the device at the patent foramen ovale. Other
details regarding the locking element described above as well as
similar devices may be found in U.S. Pat. No. 5,861,003, which is
hereby incorporated by reference in its entirety. Preferably, upon
deployment and positioning of the device 200, the locking element
228 secures the locking string to retain the device 200 is the
deployed position. The locking string may also be drawn proximally
to increase the clamping force of the device 200 on the septa of
the patent foramen ovale. It will be appreciated that the device
200 may still be self-expanding, with the locking string also
mechanically actuating the device 200.
[0102] In some embodiments, the device 200 may be made by laser
cutting flat stock sheet. In another embodiment, the device 200 and
the eyelets 230 may comprise a metal wire such as stainless steel,
Nitinol, Elgiloy, or others which can be determined through routine
experimentation by those of skill in the art.
[0103] FIG. 2B illustrates an alternative embodiment of a
self-expanding closure device including at least one eyelet, and
more preferably, a plurality of eyelets 230 to assist with collapse
of device 200 into a delivery device. The device 200 may have a
proximal segment 206, an intermediate segment 210, and a distal
segment 208 like the embodiment of FIG. 2A, and preferably is
formed from a single wire forming three similar shaped segments,
which may be generally looped or oval in shape. The eyelets 230 are
integrally formed by small loops made in the wire, preferably at
the proximal end 202, distal end 204, and at connecting portions
211a and 211b. In one embodiment, the eyelets 230 are configured to
receive an actuator or core 259, such as hypotubing, solid wire or
a guidewire, to releasably secure the device 200 and stress the
wire in a longitudinally stretched position during deployment as
shown in FIG. 2B. Upon confirmation of optimal positioning in the
patent foramen ovale or other structure, the core may be retracted
proximally, thereby releasing the segments 208, 210 and 206.
Further details regarding the delivery of this device are described
below.
[0104] For use in a patent foramen ovale, the segments 206, 208,
210 of the device 200 in one embodiment has an expanded diameter
within the range of from about 1 cm to about 5 cm, and, in a
further embodiment, about 2.5 cm. When the device 200 is
longitudinally stretched, the overall length from the distal end
204 to the proximal end 202 is preferably within the range of about
4 cm to about 20 cm and, in one embodiment, about 8 cm. Preferably
the wire 212 has a diameter of 0.001-0.03 in.
[0105] Although the device 200 is shown having a paperclip-like
shape, it is envisioned that a number of variations of this shape
can be utilized to provide the same results. For example, a bend
may be provided in the device to aid in closure. For example, a
bend may be placed in the intermediate segment 210, such that the
device 200 is sized and configured to conform to the shape of the
patent foramen ovale. Also, other non-circular or round shapes may
be used for each segment, rather than the annular shape, as
discussed above.
[0106] FIG. 5 illustrates the closure device 200 implanted in a
patent foramen ovale 120, The patent foramen ovale 120 includes a
septum primum 116 having a surface 126 adjacent the left atrium
104, and a septum secundum 118 having a surface 124 adjacent the
right atrium 114. A tunnel or channel 122 is located between the
septum primum 116 and septum secundum 118. The closure device 200
may be delivered to the patent foramen ovale 120 using any suitable
technique, such as described below. Once positioned, the distal
segment 208 is positioned over the tip 130 of the septum primum 116
and lies along the surface 126 of the septum primum 116 adjacent
the left atrium 104. The intermediate segment 210 lies between the
septum primum 116 and septum secundum 118 in channel 122. The
proximal segment 206 is positioned over the tip 128 of the septum
secundum 118 and lies along the surface 124 of the septum secundum
118 adjacent the right atrium 114. After being delivered, the
closure device 200 exerts a force on the septum primum 116 and
septum secundum 118 to draw the two closer together, either through
mechanical actuation or self-expansion of the device. In one
embodiment, the proximal and distal segments are identical in
shape, and may have identical shapes that form mirror images of
each other across the patent foramen ovale to equally apply
compressive force to both sides of the patent foramen ovale.
[0107] In one embodiment, the closure device 200 is designed to be
implanted using a deployment catheter, such as described with
respect to FIGS. 8-12 below. As shown in FIG. 6, the device 200 is
designed to remain in a delivery or elongated state while in the
catheter (not shown). In this delivery state, the device 200 can
assume a generally elongate configuration wherein the proximal end
202 and distal end 204 are pulled apart from each other in a
generally linear manner. Upon delivery to the patent foramen ovale,
the device 200 is radially expanded (FIG. 7) into a clip or
generally S-shaped configuration to occlude or close the patent
foramen ovale. As illustrated, when expanded, the proximal and
distal segments 202, 204 of the device are drawn relatively closer
to the intermediate segment. In one embodiment, the device is
preferably attached via detachment element 214 to a delivery device
such as an actuator prior to deployment, and is then detached at
detachment element 214 when properly positioned. In a further
embodiment, the detachment element 214 may use a tether line in
addition to or instead of a threaded fitting. Tether lines are
described in detail in U.S. Pat. Nos. 6,214,029, 6,440,152, and
6,551,344, which are incorporated in their entirety herein. The
procedure for placing the closure device and delivery device will
be described in further detail hereinafter.
[0108] As shown in FIGS. 8-11, a closure device deployment system
is provided for delivery of a closure device to a patent foramen
ovale. Referring to FIG. 8, a closure device deployment system 240
comprises generally a catheter 242 for placing a detachable closure
device 200 within a body cavity or lumen. The catheter 242
comprises an elongate flexible tubular body 246, extending between
a proximal end 248 and a distal end 250. The catheter is shown in
highly schematic form, for the purpose of illustrating the
functional aspects thereof. The catheter body will have a
sufficient length and diameter to permit percutaneous entry into
the vascular system, and transluminal advancement through the
vascular system to the desired deployment site. For example, in an
embodiment intended for access at the femoral artery and deployment
within the patent foramen ovale, the catheter 242 will have a
length within the range of from about 50 cm to about 150 cm, and a
diameter of generally no more than about 15 French. Further
dimensions and physical characteristics of catheters for navigation
to particular sites within the body are well understood in the art
and will not be further described herein.
[0109] The flexible body can be manufactured in accordance with any
of a variety of known techniques. In one embodiment, the flexible
body 246 is extruded from any of a variety of materials such as
HDPE, PEBAX, nylon, polyimide, and PEEK. Alternatively, at least a
portion or all of the length of the tubular body may comprise a
spring coil, solid walled hypodermic needle or other metal tubing,
or braided reinforced wall, as are known in the art.
[0110] The tubular body 246 is further provided with a handle 252
generally on the proximal end 248 of the catheter 242. The handle
252 may be provided with a plurality of access ports. Generally,
handle 252 is provided with an access port which may be used as a
guidewire port in an over the wire embodiment, and a deployment
wire or actuator port. Additional access ports such as a contrast
media introduction port, or others may be provided as needed,
depending upon the functional requirements of the catheter. The
handle 252 permits manipulation of the various aspects of the
closure device deployment system 240, as will be discussed below.
Handle 252 may be manufactured in any of a variety of ways,
typically by injection molding or otherwise forming a handpiece for
single-hand operation, using materials and construction techniques
well known in the medical device arts.
[0111] An actuator 244, as described below, is provided in
accordance with one embodiment of the present invention, used to
releasably engage and deploy the closure device 200. Any of a
variety of structures such as solid cores, polymeric or metal
single or multiple strand wires, ribbons, or tubes can be used. The
actuator 244 may be retracted as with a pullwire design, or rotated
as with a torque rod design, as will be discussed herein. The
actuator 244 may be hollow or solid.
[0112] In use, the deployment catheter is percutaneously introduced
into the vascular system and transluminally advanced into the heart
and, subsequently, to the patent foramen ovale using techniques
which are known in the art.
[0113] The patent foramen ovale may be accessed via catheter
through a variety of pathways. It may be accessed from the arterial
circuit. The catheter is introduced into the arterial vascular
system, preferably in the femoral artery, and guided up the
descending thoracic and/or abdominal aorta. The catheter may then
be advanced into the left ventricle through the aortic outflow
tract. Once in the left ventricle, the catheter may be directed up
through the mitral valve and into the left atrium. When the
catheter is in the left atrium, it may be directed into the patent
foramen ovale and the closure device deployed.
[0114] Alternatively, the patent foramen ovale may be accessed from
the venous circuit. The catheter may be introduced into the venous
system, preferably in the femoral vein, advanced into the inferior
vena cava or superior vena cava and guided into the right atrium.
The catheter may then be directed to the patent foramen ovale.
Alternatively, once in the right atrium, the catheter may be
advanced through the tricuspid valve and into the right ventricle
and directed to the ventricular septal defect and the closure
device deployed.
[0115] As shown in FIG. 10, in a preferred construction, a catheter
242 having a single lumen is illustrated. Also shown is an actuator
244 that acts as the actuator for deploying the device 200. In the
illustrated embodiment, the actuator may be an elongate body such
as a core wire that extends to the handle 252, and more preferably
may be hollow to provide a passageway for the locking element 228
described with respect to FIG. 2B above. The actuator 244 may be
removably attached to the proximal end 202 or other point of
attachment on the closure device 200, such as through a threaded
attachment at detachment element 214. Proximal retraction of the
actuator 244 while resisting proximal motion of the closure device
200 or distally pulling on the closure device will cause elongating
of the closure device 200 into its delivery state, as has been
discussed. The closure device 200 is preferably loaded into the
deployment catheter 242 as shown in FIG. 10. The actuator 244 may
be locked or removably attached with respect to the closure device
200, and later severed or otherwise detached to enable removal of
the deployment catheter 242 and proximal retraction of the actuator
244. In addition to a threaded connection, locking of the actuator
244 with respect to the closure device 200 may be accomplished in
any of a variety of ways. For example, depending upon the desired
catheter design, locking may be accomplished by using interference
fit or friction fit structures, tether line, adhesives, a knot, or
other technique known to one of ordinary skill in the art.
[0116] In the embodiment illustrated in FIG. 10, the actuator 244
is releasably connected to the proximal end of the closure device
200. This permits distal advancement of the closure device 200
through the catheter 242 by distal movement of the actuator 244.
The proximal end of the actuator 244 may be connected to any of a
variety of controls, including rotational knobs, levers and slider
switches, depending upon the design preference. To deploy the
device 200, the actuator is pushed distally until closure device
200 exits the catheter 242. Upon exiting the catheter, the locking
element as described above may be actuated to cause the device to
move to its deployed configuration. Alternatively, the device 200
may self-expand as it exits the catheter. After positioning of the
device is confirmed, the actuator 244 is released from the device
200, and the actuator and deployment catheter are removed. Where a
locking element is used, this locking element may be cut, released
or otherwise secured to fix the position of the closure device.
Further details on delivery methods are described below with
respect to FIGS. 12A-12E.
[0117] When delivering a device such as in the embodiment of FIG.
2B, in another embodiment, a detachment element 214 may be provided
that comprises a threaded attachment located on the distal segment
208. In this embodiment, the core wire 259 is inserted through the
eyelets 230 of the closure device 200 and is distally threaded to
connect with the detachment element, causing elongation of the
device 200 into its delivery state. The closure device 200 is
inserted into the deployment catheter 242 with the core wire
inserted through the eyelets 230 of the device 200 and attached at
the distal segment 208. The core wire may be advanced out of the
deployment catheter to position the closure device in the patent
foramen ovale, as discussed below. The core wire may then be
detached from the distal segment 208 and retracted proximally to
deploy the device 200. A hollow push rod positioned proximal to the
closure device and over the core wire 259 may be used to assist in
releasing the closure device from the core wire. Alternatively, the
closure device may be positioned distally beyond the distal end of
the deployment catheter 242, and interference between the
deployment catheter 242 and the closure device 200 may be used to
assist in releasing the closure device from the core wire. As
discussed, the detachment element 214 may alternatively comprise a
tether line, a threaded fitting, or other technique as is known to
one of ordinary skill in the art to releasably secure the closure
device 200 to the core wire 259. It will also be appreciated that
in the embodiment of FIG. 2B, no detachment element may even be
necessary other than the eyelets 230 that secure the closure device
200 to the core wire 259. As the core wire is retracted proximally
from the eyelets 230 in the segments 206, 208, 210, the device 200
is released to its deployed shape, securing the septa 116, 118 of
the patent foramen ovale, as described further below.
[0118] The actuator 244 or core wire 259 in one embodiment extends
axially throughout the length of the catheter body 246, and is
attached at its proximal end to a control on the handle 252. The
actuator 244 or core wire 259 may comprise any of a variety of
structures which has sufficient lateral flexibility to permit
navigation of the vascular system, and sufficient axial column
strength to be pushed through the catheter 242. Any of a variety of
structures such as hypotube, solid core wire, "bottomed out" coil
spring structures, or combinations thereof may be used, depending
upon the desired performance of the finished device. In one
embodiment, the core wire comprises stainless steel tubing.
[0119] As used herein, the term "core wire" is intended to include
any of a wide variety of structures which are capable of
transmitting axial tension or compression such as a pushing or
pulling force with or without rotation from the proximal end 248 to
the distal end 250 of the catheter 242. Thus, monofilament or
multifilament metal or polymeric rods or wires, woven or braided
structures may be utilized. Alternatively, tubular elements such as
a concentric tube positioned within the outer tubular body 246 may
also be used as will be apparent to those of skill in the art.
[0120] FIGS. 11A-11D illustrate an alternate construction wherein a
closure device is biased toward its deployment configuration, such
as being made from a shape memory material, and may be radially
enlarged or reduced by rotating a torque element extending through
the deployment catheter. Referring to FIGS. 11A and 11C, a
rotatable torque rod 260 extends axially through the deployment
catheter 242, and also extends through the closure device 200,
preferably through at least one internally threaded portion
provided in the closure device 200. For example, as shown in FIG.
11B, an externally threaded portion 262 of torque rod 260 may
engage an internally threaded portion within connecting segment
211a. The rotatable torque rod may be encased in a plurality of
tubes (not shown) within the closure device that are positioned
approximately diametrically within any or all of segments 206, 208,
and 210, said tubes preferably attached to the segments at each end
of each tube. These tubes serve to guide the torque rod from the
proximal end of the device through the connecting segments to the
distal end. The proximal end of the torque rod 260 may be connected
at a proximal manifold to a manual rotation device such as a hand
crank, thumb wheel, rotatable knob or the like. Alternatively, the
torque rod 260 may be connected to a power driven source of
rotational energy such as a motor drive or air turbine.
[0121] The terms torque rod or torque element are intended to
include any of a wide variety of structures which are capable of
transmitting a rotational torque throughout the length of a
catheter body. For example, solid core elements such as stainless
steel, nitinol or other nickel titanium alloys, or polymeric
materials may be utilized. In an embodiment intended for
implantation over a guidewire, the torque rod 260 is preferably
provided with an axially extending central guidewire lumen. This
may be accomplished by constructing the torque rod 260 from a
section of hypodermic needle tubing, having an inside diameter of
from about 0.001 inches to about 0.005 inches or more greater than
the outside diameter of the intended guidewire. Tubular torque rods
260 may also be fabricated or constructed utilizing any of a wide
variety of polymeric constructions which include woven or braided
reinforcing layers in the wall. Torque transmitting tubes and their
methods of construction are well understood in the intracranial
access and rotational atherectomy catheter arts, among others, and
are not described in greater detail herein.
[0122] One or more distal portions of the torque rod may be
threaded as shown in FIGS. 11B and 11D. More particularly, threaded
portions 262 may be provided on torque rod 260, to correspond to
internally threaded portions of the distal segment 208 (FIG. 11D)
or the connecting portions 211a and 211b (FIG. 11B). A distal
threaded portion or distal rotating coupler, not shown, may be
provided at the distal end 204 of the device to receive the distal
end of the torque rod. As will be appreciated by those of skill in
the art in view of the disclosure herein, in one embodiment,
rotation of the torque rod 260 in a first direction relative to the
closure device 200 will cause the torque rod 260 to advance
distally. This distal advancement will stress the device and result
in an axial elongation and radial reduction of the closure device
200 as the torque rod 260 is advanced distally into the threaded
apertures of the closure device 200. Rotation of the torque rod 260
in a reverse direction will cause a proximal retraction of the
torque rod 260, thus enabling a radial enlargement and axial
shortening of the closure device 200.
[0123] In another embodiment, similar to that described with
respect to FIG. 2B above where only the distal end 204 of the
device 200 is threaded, the torque rod may be inserted through
eyelets 230 formed at the proximal end 202 and connecting segments
211a and 211b of the device, thereby axially elongating the device
200, and threadingly engaging the distal end 204. Disengaging the
torque rod 260 from the distal segment 208 will release the segment
208, permitting the segment 208 to collapse in its deployed
position. The remaining segments 206, 210 may be released by
proximally retracting the torque rod 260 from the eyelets 230
corresponding to each segment 206, 210.
[0124] With the torque rod 260 threadingly engaging the device 200,
upon placement of the closure device 200 at the desired
implantation site, the torque rod 260 is rotated in a direction
that produces an axial proximal retraction. This allows radial
enlargement of the radially outwardly biased closure device 200 at
the implantation site. Continued rotation of the torque rod 260
will cause the threaded portion to exit proximally through the one
or more threaded apertures provided on the closure device 200.
[0125] With the torque rod 260 extending through the deployment
catheter 242, the device 200 may be provided beyond the distal end
of the deployment catheter 242, so that when the torque rod is
rotated to move the torque rod proximally, the distal force applied
by the deployment catheter on the device 200 allows the device to
release the torque rod. The deployment catheter 242 may also be
provided with an antirotation lock (not shown) between a distal end
of the catheter 242 and the closure device 200. In general, the
rotational lock may be conveniently provided by cooperation between
a first surface on the distal end of the deployment catheter 242,
which engages a second surface on the closure device 200, to
rotationally link the deployment catheter 242 and the closure
device 200. Any of a variety of complementary surface structures
may be provided, such as an axial extension on one of the first and
second surfaces for coupling with a corresponding recess on the
other of the first and second surfaces. Such extensions and
recesses may be positioned laterally offset from the axis of the
catheter. Alternatively, they may be provided on the longitudinal
axis with any of a variety of axially releasable anti-rotational
couplings having at least one flat such as a hexagonal or other
multifaceted cross sectional configuration.
[0126] Any other means known may be used for temporarily attaching
the closure device to a delivery system such as a deployment
catheter or actuator. For example, any of a variety of interference
fit such as threaded fit or snap fit, pin/loop combinations,
interfering diameters, or heat dissociable solders or polymer bonds
may be utilized.
[0127] The closure device deployment system 240 thus permits the
closure device 200 to be maintained in a low crossing profile
configuration, to enable transluminal navigation to a deployment
site. Following positioning at or about the desired deployment
site, distal advancement or proximal retraction of an actuator
enables the closure device 200 to radially enlarge. Radial
enlargement in one embodiment occurs under the device's own bias.
Alternatively, certain embodiments of the closure device can be
enlarged under positive force, such as by inflation of a balloon or
by a mechanical mechanism as is discussed elsewhere herein. Once
the clinician is satisfied with the position of the closure device
200, such as by injection of dye and visualization using
conventional techniques, the actuator is proximally retracted
thereby enabling detachment of the closure device 200 from the
deployment system 240.
[0128] If, however, visualization reveals that the closure device
200 is not at the location desired by the clinician, the closure
device 200 can be radially reduced and axially elongated, thereby
enabling repositioning of the closure device 200 at the desired
site. In the embodiment of FIG. 10, this repositioning is allowed
by pulling the closure device 200 partially or wholly back into the
catheter before release of the detachment element. In the
embodiment of FIGS. 11A-D, the torque rod can be distally advanced
to reengage the internal threading of the closure device. In some
embodiments the torque rod will be guided within tubes attached to
the segments (discussed previously). Thus, the closure device 200
can be enlarged or reduced by the clinician to permit repositioning
and/or removal of the closure device 200 as may be desired.
[0129] With reference to FIGS. 12A-12E, a closure device 200 (shown
schematically) is preferably positioned within a patent foramen
ovale. Initially, the device 200 is collapsed inside a deployment
catheter 242. The catheter 242 is then positioned at or near the
patent foramen ovale 120, as shown in FIG. 12A, more preferably
through the channel 122 between the septum primum and septum
secundum. Then, as shown in FIG. 12B, the distal segment 208 of the
device is exposed and is pushed out, preferably using an actuator
as described above, and deployed over the septum primum 116. The
deployment catheter is retracted while releasing the intermediate
segment 210 to be positioned inside the patent foramen ovale
channel 122 (shown in FIG. 12C), along a surface of the septum
primum and the septum secundum. Lastly, the proximal segment 206 is
released from the deployment catheter and positioned against the
septum secundum 118 (FIG. 12D). The positioning of each of the
segments relative to the septum primum and septum secundum can
occur due to a natural bias of the device as it exits the catheter,
due to a mechanical actuation of the distal segment into this
position, as described above, or due to a combination of natural
bias and mechanical actuation. In another embodiment, a core may
hold each segment 206, 208, 210 in a delivery or elongated state
until proper positioning may be confirmed. The core may then be
retracted, releasing the device 200 for deployment.
[0130] After optimal positioning and closure is achieved, the
device 200 can then be detached from the delivery system, as shown
in FIG. 12E. In one embodiment, detachment element 214 comprises a
flexible segment such as a hinge or braid to allow the device 200
to assume a final implanted attitude without undue distortion
applied to the implant or the septa from the deployment catheter.
The device 200 can also be captured and retrieved at any time
during the procedure as long as it is not fully detached from the
delivery system. Once in position, the device clips the patent
foramen ovale closed by exerting a force on the septum primum and
septum secundum to draw the two together.
[0131] With reference to FIGS. 13-14, an alternative embodiment of
a closure device in accordance with the present invention is shown.
The closure device 300 preferably is shaped to form a clip-like
device, similar to the closure device of FIG. 2A. The closure
device has a proximal end 302 and a distal end 304. The closure
device generally has three sections: a proximal segment 306, a
distal segment 308, and an intermediate segment 310. In contrast to
the device shown in FIG. 2A, in the closure device 300 shown in
FIG. 13, the intermediate segment 310 is preferably a single
straight wire preferably covered in a sleeve 324, rather than an
elongated annular wire or loop. The intermediate segment 310 may
also be cut from flat stock sheet. Both the proximal and distal
segments 306, 308 are generally annular in shape as described
above. The segments 306, 308, 310 are formed from a wire 312 and
are connected by connecting portions 311a and 311b, similar to the
embodiment discussed above. The segments 306, 308, 310 form an
integral structure for closing or occluding a patent foramen ovale.
The closure device 300 is also preferably provided with a
detachment element 314 on proximal end, as discussed above.
[0132] When delivered, the intermediate segment 310 is positioned
in the channel between the septum primum 116 and the septum
secundum 118 to close the patent foramen ovale 120, as was
described in the embodiment above. The distal segment 308 is
preferably positioned in the left atrium, while the proximal
segment 306 is positioned in the right atrium. The closure device
300 is designed to be implanted using a delivery system, such as
described above, and may have a collapsed or delivery state, as
shown in FIG. 14.
[0133] Preferably, the wire 312 comprises a metal such as stainless
steel, Nitinol, Elgiloy, or others which can be determined through
routine experimentation by those of skill in the art. The wire may
also be biodegradable. Wires having a circular or rectangular
cross-section may be utilized depending upon the manufacturing
technique. In one embodiment, a circular cross section wire is cut
such as by known laser cutting techniques from tube stock. The
closure device is preferably an integral structure, such as a
single ribbon or wire, or element cut from a tube stock.
[0134] The intermediate segment 310 is preferably covered with a
sleeve 324. The wire of the proximal and distal segments 306, 308
may also be covered with a sleeve. The sleeve 324 may comprise any
of a variety of materials which facilitate cellular in-growth, such
as ePTFE. The suitability of alternate materials for sleeve 324 can
be determined through routine experimentation by those of skill in
the art. In one embodiment, the sleeve 324 comprises two layers.
The two layers may be bonded to each other around the wire 312 in
any of a variety of ways, such as by heat bonding with or without
an intermediate bonding layer such as polyethylene or FEP,
adhesives, sutures, and other techniques which will be apparent to
those of skill in the art in view of the disclosure herein. The
sleeve 324 in one embodiment preferably is securely attached to the
device 300 and retains a sufficient porosity to facilitate cellular
ingrowth and/or attachment. In one embodiment, the segments 324,
310 may be configured to occlude the channel 122 in addition to the
closure of the patent foramen ovale induced by the proximal and
distal segments 306, 308.
[0135] Preferably, the device 300 includes a locking element 328
and retention elements 330 for retaining the locking element 328 to
the closure device 300, as described above. The locking element 328
is used to longitudinally collapse the device and hold it in place
at the patent foramen ovale. The locking element 328 preferably
comprises a locking string which is preferably used to both expand
and lock the device at the patent foramen ovale 120.
[0136] For use in a patent foramen ovale, the closure device 300
has an expanded diameter within the range of from about 1 cm to
about 5 cm, and, in one embodiment, about 2.5 cm. The overall
length of the closure device 300 from the distal end 308 to the
proximal end 306 is preferably within the range of from about 4 cm
to about 20 cm and, in one embodiment, about 8 cm. Preferably the
wire has a diameter of 0.001-0.03 in.
[0137] Single Clip or Hook Embodiment
[0138] With reference to FIGS. 15-17, there is illustrated an
additional embodiment of a closure device 400. The device comprises
a proximal or an anterior section 402 and a distal or posterior
section 404. A first axis 406 passing through the anterior section
402, and a second axis 408 passing through the posterior section
404, generally parallel to one another, are shown. The anterior
section 402 comprises wings 409, which are used to anchor the
device into the correct atrium, preferably the right atrium. The
wings 409 preferably extend to beyond the edges of the patent
foramen ovale to provide additional support to device 400. The
anterior and posterior sections 402, 404 are integral and form a
structure which hooks over the tip 130 of the septum primum 116.
The device is provided with a loop 410 integral with the structure
to attach the device 400 to the delivery device. The anterior
section 402, posterior section 404, and loop 410 are an integral
structure and are formed of a single wire 412. The device is
preferably shaped like a hook, as can be seen with reference to
FIG. 16, and is preferably self-expanding into the hook shape.
[0139] The anterior section 402 and posterior section 404 are
positioned between the septum primum 116 and the septum secundum
118 and hook over the septum primum 116 to close a patent foramen
ovale 120, as shown in FIG. 17. This embodiment stabilizes the flap
of the patent foramen ovale 120. The posterior section 404 is
positioned in the left atrium, while the anterior section 402 is
positioned in the patent foramen ovale and extends out into the
right atrium. The anterior section 402 is preferably of such a
length as to extend along the septum primum 116 to prevent the
septum primum 116 from displacing into the left atrium 104. The
posterior section 404 prevents the tip 130 of the septum primum 116
from displacing into the left atrium 104 while the anterior section
402 secures the device 400 to the septum primum 116. The anterior
section 402 is preferably sized and configured to extend along the
right atrium 114 side of the septum primum 116 such that the base
of the septum primum 116 provides support to the device 400, which
prevents displacement of the septum primum tip 130 into the left
atrium 104.
[0140] Preferably, the wire 412 comprises a metal such as stainless
steel, Nitinol, Elgiloy, or others which can be determined through
routine experimentation by those of skill in the art. The wire may
also be biodegradable. Wires having a circular or rectangular
cross-section may be utilized depending upon the manufacturing
technique. In one embodiment, a circular cross section wire is cut
such as by known laser cutting techniques from tube stock. The
closure device is preferably an integral structure, such as a
single ribbon or wire, or element cut from a tube stock.
[0141] A portion of the device 400 is preferably covered with a
sleeve 424 as shown in FIG. 16. The sleeve 424 bridges the fossa
and patent foramen ovale 120, while the wire structure stabilizes
the flap of the patent foramen ovale 120. The sleeve 424 may
comprise any of a variety of materials which facilitate cellular
in-growth, such as ePTFE. The suitability of alternate materials
for sleeve 424 can be determined through routine experimentation by
those of skill in the art. In one embodiment, the sleeve 424
comprises two layers. The two layers may be bonded to each other
around the wire 412 in any of a variety of ways, such as by heat
bonding with or without an intermediate bonding layer such as
polyethylene or FEP, adhesives, sutures, and other techniques which
will be apparent to those of skill in the art in view of the
disclosure herein. The sleeve 424 in one embodiment preferably is
securely attached to the device 400 and retains a sufficient
porosity to facilitate cellular ingrowth and/or attachment.
[0142] Referring to FIGS. 18A-E, a closure device 400 such as
described above is preferably positioned within a patent foramen
ovale to be closed or occluded. In a patent foramen ovale
application, the distal end of a deployment catheter 242 is
positioned at or near the patent foramen ovale 120, as shown in
FIG. 18A. The position may be confirmed using fluoroscopy,
echocardiography, or other imaging. The device 400 is initially in
a collapsed state within catheter 242, such as described above. The
left atrium segment 404 of the device 400 is exposed and positioned
on the septum primum 116 by advancing or rotating actuator 244 (not
shown), as discussed herein. See FIG. 18B. The anterior segment 402
is then positioned inside the patent foramen ovale channel 122 and
on the septum secundum 118 again by advancing or rotating actuator
244 (not shown) (FIG. 18C). One of ordinary skill in the art will
recognize that actuation of the device 400 may be accomplished as
mentioned above. For example, actuation of the device 400 may be
mechanically induced, self-expanding, a combination of mechanical
and self-expanding. Additionally, deployment and detachment of the
device may be accomplished as discussed above. For example, the
device may be deployed via a tether line or torque rod, and
detached accordingly as discussed previously. In one embodiment, a
tether line, core wire or other actuator 244 may be attached to
loop 410 for releasably deploying the device.
[0143] After optimal positioning and sealing is achieved, as shown
in FIG. 18D, the device 400 can then be detached from the delivery
system, as shown in FIG. 18E. The device 400 can also be captured
and retrieved at any time during the procedure as long as it is not
detached from the actuator 244.
[0144] Other Clip Embodiments
[0145] Referring to FIGS. 19-20, there is illustrated another
preferred embodiment of the present invention. The closure device
440 comprises a proximal or an anterior section 442, a distal or
posterior section 444 and an intermediate section 446. The
posterior section 444 comprises two legs 449 that extend generally
parallel to a longitudinal axis of the device which form an
exaggerated "T" shape with the intermediate section 446. The
anterior section 442 has a generally rectangular shape. Sections
442, 444, and 446 may be self-expanding and form an integral
structure 452, or may be separately joined such as by a hinged
connection. In some embodiments, anchors 447 may be provided to
secure the implant against the septum primum 116 and septum
secundum 118. As illustrated, the anchors may be punched in the
anterior and intermediate section 442 and 446 and heat set or
deformed to extend proud of device 440 surface. Hole 448 may be
provided in proximal end of anterior section 442 to facilitate
attachment of a tether and the like to closure device 440.
[0146] The anterior section 442 is configured and positioned in the
right atrium, the posterior section 444 is configured to be
positioned in the left atrium, and the intermediate section 446 is
configured to be positioned between the septum primum 116 and the
septum secundum 118. The posterior section 444 hooks over the
septum primum 116 and the anterior section 442 hooks over the
septum secundum 118 to occlude or close a patent foramen ovale 120,
as shown in FIG. 20. The septum primum 116 and septum secundum 118
are held together by the clamping force exerted by the clips
defined between sections 444 and 446, and sections 442 and 446. The
design minimizes the amount of material exposed to blood flow in
the left and right atria, thereby reducing the chance of clot
formation. The shape is designed to fit the anatomy without
distending tissue, thereby reducing the chance of leaks and
promoting health.
[0147] In some embodiments, the clip structure can be made by laser
cutting flat stock sheet. Preferably, the clip structure comprises
a metal such as stainless steel, Nitinol, Elgiloy, or others which
can be determined through routine experimentation by those of skill
in the art.
[0148] Referring to FIG. 21A, a closure device 440 is preferably
delivered to a defect to be occluded, such as a patent foramen
ovale. In a patent foramen ovale application, the distal end of the
deployment catheter 242 is positioned at or near the patent foramen
ovale 120, as shown in FIG. 21A. The position may be confirmed
using fluoroscopy, echocardiography, or other imaging. The device
440 is initially in a collapsed state within catheter 242. The
device 440 may be releasably attached to an actuator 244, which may
be a push rod. The distal end of the deployment catheter 242 is
advanced between the septum primum 116 and septum secundum 118 as
shown in FIG. 21B. The posterior portion 444 is advanced out of the
distal end of the deployment catheter 242 and over the septum
primum 116, as shown in FIG. 21C, preferably by withdrawing the
catheter 242 proximally. As the catheter 242 is withdrawn, the
posterior portion 444 flips over into the left atrium 104 and hooks
over the septum primum 116. The intermediate section 446 and
anterior sections 442 are then delivered, as shown in FIG. 21D, by
further withdrawing the catheter 242 until anterior section 442
flips over the septum secundum 188. After optimal positioning and
sealing is achieved, as shown in FIG. 21D, the device 440 can then
be detached from the actuator or tether line 260 and deployment
catheter 242. The device 440 can also be captured and retrieved at
any time during the procedure as long as it is not detached from
the actuator.
[0149] In one embodiment, the device 440, and more particularly the
anterior portion 442, has a length L of about 1 inch, thickness t
of about 0.02'', and a width W of about 0.475''. The length and
width of the anterior portion are preferably greater than the
length and width of the posterior portion. More preferably, the
anterior portion may be approximately twice as long or greater than
the posterior portion, and about 25% or more wider than the
posterior portion.
[0150] With reference to FIGS. 22A-C and 23, there is illustrated
another preferred embodiment of the present invention. The device
470 is preferably made from a single wire structure, and comprises
a proximal or an anterior section 472, a distal or posterior
section 474, and an intermediate section 476. The posterior section
474 comprises wings 479 which are used to anchor the device into
the left atrium. The intermediate section 476 may include crossed
wire portions as shown in FIG. 22A or non-crossed wire portions as
shown in FIG. 22B. The anterior section may be hexagonal in shape.
The anterior, posterior, and intermediate sections 472, 474, 476
are integral and form a structure which hooks over the septum
primum and the septum secundum. The device may be provided with at
least one loop 480 at a proximal end of the device integral with
the structure. A second loop 481 may be provided at the
intersection of the anterior and intermediate sections. As shown in
FIG. 22B, the device 470 may also comprise a third loop 484 at the
distal end of the posterior section 474. The function of the first
loop 480, second loop 481, and third loop 484 will be discussed
below with reference to loading and deployment of the device 470.
The anterior section 472, posterior section 474, intermediate
section 476 and at least one loop 480 are preferably an integral
structure and are formed of a single wire 482. The device is
preferably shaped like a clip, as can be seen with reference to
FIG. 23, when the device is deployed.
[0151] As shown in FIG. 23, the anterior section 472 is positioned
in the right atrium, the posterior section 474 is positioned in the
left atrium, and the intermediate section 476 is positioned between
the septum primum 116 and the septum secundum 118. The posterior
section 474 hooks over the septum primum 116 and the anterior
section 472 hooks over the septum secundum 118 to occlude a patent
foramen ovale 120, as shown in FIG. 23.
[0152] Preferably, the wire 482 comprises a metal such as stainless
steel, Nitinol, Elgiloy, or others which can be determined through
routine experimentation by those of skill in the art. The wire may
also be biodegradable. Wires having a circular or rectangular
cross-section may be utilized depending upon the manufacturing
technique. In one embodiment, a circular cross section wire is cut
such as by known laser cutting techniques from tube stock. The
closure device is preferably an integral structure, such as a
single ribbon or wire, or element cut from a tube stock.
[0153] The device may be similarly dimensioned as the embodiment of
FIG. 19A. For use in a patent foramen ovale, the overall width of
device 470 may be any value or range of values from about 1 cm to
about 5 cm, and, in one embodiment, may be about 2.5 cm. The
overall length of the closure device 470 may be any value or range
of values from about 4 cm to about 20 cm and is, in one embodiment,
about 8 cm. Preferably the diameter of the wire may be any value or
range of values from about 0.001-0.030 in, and in one preferred
embodiment is about 0.015 in.
[0154] In some embodiments, the anterior section 472 may have a
covering or be laminated. FIGS. 22B and 22C show the device of FIG.
22B with a laminate structure 483 covering the anterior section
472. In some embodiments, the lamination may comprise any of a
variety of materials which facilitate cellular in-growth, such as
ePTFE. The suitability of alternate materials for the lamination
material can be determined through routine experimentation by those
of skill in the art. In one embodiment, two layers of lamination
are provided. The two layers may be bonded to each other around the
wire 482 on the anterior section 472 in any of a variety of ways,
such as by heat bonding with or without an intermediate bonding
layer such as polyethylene or FEP, adhesives, sutures, and other
techniques which will be apparent to those of skill in the art in
view of the disclosure herein. The lamination material in one
embodiment preferably is securely attached to the device 470 and
retains a sufficient porosity to facilitate cellular ingrowth
and/or attachment.
[0155] Referring to FIGS. 24A-D, there is illustrated a preferred
method of loading the device illustrated in FIG. 22B for delivery.
A mounting shaft 486 is inserted through the second loop 481 of the
device 470 such that the anterior section 472 is closer to the
proximal end 490 of the mounting shaft 486 and the posterior
section 474 is closer to the distal end 488 of the mounting shaft
486, as shown in FIG. 24A. As shown in FIG. 24B, the posterior
section 474 and the intermediate section 476 are bent distally such
that each wire of the intermediate section 476 is placed along
opposite sides of the mounting shaft 486. The portion between the
intermediate section 476 and the posterior section 474 rests on the
mounting shaft 486 with the third loop 484 extending somewhat
radially from the mounting shaft 486. The third loop 484 is then
bent over the distal end 488 of the mounting shaft 486, as shown in
FIG. 24C.
[0156] A tether line 492 is looped through the first loop 480 on
the proximal end of the device. A recapture wire 494 is inserted
through the tether line 492 loop. The recapture wire 494 preferably
does not pass through the first loop 480 of the device, as shown in
FIG. 24D. When the tether line 492 is drawn proximally, the tether
line cinches the first loop 480 of the device 470. The tether line
492 is then drawn proximally such that the anterior section 472 is
an adjacent to the mounting shaft 486. In another embodiment, the
mounting shaft 486 may first be inserted through the first loop 480
and fixed with a tether line 492, followed by the mounting
procedure as explained previously. The device 470, tether line 492,
recapture wire 494, and mounting shaft 486 are then inserted into a
sheath (not shown).
[0157] The placement of the closure device 470 is schematically
shown in FIG. 23. For deployment, the sheath is advanced through
the channel 122 of the patent foramen ovale, such that the distal
end of the sheath extends into the left atrium 104 beyond the tip
130 of the septum primum 116. The mounting shaft 486 is held in
place while the sheath is slowly retracted proximally until the
posterior section 474 is released from the sheath. The wings 479 of
the posterior section 474 may be extended out by slightly advancing
the sheath distally while holding the mounting shaft 486 in place.
The mounting shaft 486 and the sheath are then retracted proximally
until the wings 479 of the posterior section 474 engage the septum
primum 116. The mounting shaft 486 is held in place while the
sheath is retracted proximally allowing the wings 479 to secure the
septum primum. The sheath is then retracted further until the
entire device 470 is exposed.
[0158] The tether line 492 and recapture wire 494 are advanced
distally, allowing the anterior section 472 to advance and oppose
the right atrium side of the septum secundum. With the tether line
492 and recapture wire 494 still secured to the first loop 480, the
entire device 470 may be recaptured if required. The tether line
492 and recapture wire 494 may also assist in repositioning the
anterior section 472 of the device. Optimal positioning of the
device may be confirmed using fluoroscopy, echocardiography, or
other imaging. Once optimal positioning is confirmed, the mounting
shaft is retracted proximally, and the recapture wire 494 is
withdrawn proximally to release the tether line 492 loop. The
mounting shaft 486, tether line 492, recapture wire 494, and sheath
are then removed.
[0159] Referring to FIGS. 25-32, there is illustrated another
preferred embodiment of the present invention. The device is shown
in an unexpanded state in FIGS. 25 and 26. A closure device 500 is
provided having a soft distal tip 502, connected to a distal hub
504, and a soft proximal tip 506, connected to a proximal hub 508.
The device also comprises at least two sealing arms 510. The
sealing arms 510 are preferably heat-set. When the device is
expanded, the arms 510 have a generally round shape, as shown in
FIG. 27. The device 500 also comprises at least two anchors 512,
513 integrally formed with the distal and proximal hubs 504, 508
and the sealing arms 510. The anchors deflect outwards upon
expansion to retain the septum primum 116 and septum secundum 118,
as will be described. The device 500 is preferably made from a
laser-cut hypotube. The distal hub 504 and proximal hub 508 are
drawn together, thereby compressing the device 500 and expanding
the sealing arms 510 for positioning in a patent foramen ovale 120
channel 122.
[0160] Preferably, the closure device 500 is provided with one or
more retention structures for retaining the device in the patent
foramen ovale or other similar septal defects. See FIG. 26. In the
illustrated embodiment, a plurality of barbs or other anchoring
elements 522 are provided, for engaging adjacent tissue to retain
the closure device 500 in its implanted position and to limit
relative movement between the tissue and the closure device. The
illustrated barbs 522 are provided on the anchors 512, 513. The
barbs resist migration of the closure device away from the patent
foramen ovale.
[0161] The arms 510 are preferably positioned in the channel 122
between the septum primum 116 and the septum secundum 118 to close
the patent foramen ovale 120, as shown in FIG. 28. A first anchor
513 is positioned in the left atrium, while a second anchor 512 is
positioned in the right atrium. The anchors 512, 513 deflect
outwardly to secure the septum primum 116 and septum secundum 118,
to close the patent foramen ovale 120.
[0162] Preferably, the device 500 is formed of a metal such as
stainless steel, Nitinol, Elgiloy, or others which can be
determined through routine experimentation by those of skill in the
art. The material may also be biodegradable. Material having a
circular, rectangular, or other cross-section may be utilized
depending upon the manufacturing technique. One of ordinary skill
in the art will recognize various methods of manufacturing the
device 500. In one embodiment, for example, material with a
circular cross section is cut such as by known laser cutting
techniques from tube stock. The closure device is preferably an
integral structure, such as a single ribbon or wire, or element cut
from a tube stock.
[0163] The device may also comprise a sleeve over at least a
portion of the device. The sleeve may comprise any of a variety of
materials which facilitate cellular in-growth, such as ePTFE. The
suitability of alternate materials for sleeve can be determined
through routine experimentation by those of skill in the art. In
one embodiment, the sleeve comprises two layers. The two layers may
be bonded to each other around the device in any of a variety of
ways, such as by heat bonding with or without an intermediate
bonding layer such as polyethylene or FEP, adhesives, sutures, and
other techniques which will be apparent to those of skill in the
art in view of the disclosure herein. The sleeve in one embodiment
preferably is securely attached to the device 500 and retains a
sufficient porosity to facilitate cellular ingrowth and/or
attachment.
[0164] The device 500 is further provided with an expansion and
detachment element 514 at its distal end. The expansion and
detachment element 514 may be either a pull wire design (FIGS.
29-30), a turn screw design (FIGS. 31-32), a tether line, or other
method known by one of ordinary skill in the art that may be used
to collapse and lock the closure device in its expanded state. In
one embodiment, the device is preferably attached via detachment
element 514 to a delivery system as described above prior to
deployment, and is then detached at detachment element 514 when
properly positioned. The device can then be detached from the
delivery system at the same place. In one embodiment, deployment
and detachment of the device may be accomplished by torque rods, as
discussed previously with reference to FIGS. 11A-B. In another
embodiment, deployment and detachment may be accomplished by tether
lines as previously discussed. Other methods that are known by one
of ordinary skill in the art may also be used.
[0165] Umbrella and Acorn Embodiments
[0166] Referring to FIGS. 33-34, alternate structures of a closure
device in accordance with the present invention are illustrated.
The closure device 600 comprises an occluding member 602 comprising
a frame 604 and a barrier 606. In the illustrated embodiment the
frame 604 comprises a plurality of radially outwardly extending
spokes 608 each having a length within the range of from about 1 cm
to 6 cm. The device has a proximal end 610 and a distal end 612
corresponding to a proximal hub 614 and a distal hub 616. A central
hub 618 is also preferably provided between the proximal hub 614
and distal hub 616. The frame 604 and barrier 606 form a proximal
segment 620 and a distal segment 622. The designation proximal or
distal is not intended to indicate any particular anatomical
orientation or deployment orientation within the deployment
catheter. Proximal and distal segments 620, 622 are baskets which
secure the septum primum 116 and septum secundum 118 on both sides,
thus sealing the patent foramen ovale.
[0167] The spokes 608 are advanceable from a generally axially
extending orientation such as from within a tubular introduction
catheter to a radially inclined orientation. In a self-expandable
embodiment, the spokes are biased radially outwardly such that the
closure member expands to its enlarged, implantation cross-section
under its own bias following deployment from the catheter.
Alternatively, the closure member may be enlarged using any of a
variety of enlargement structures such as an inflatable balloon, or
a catheter for axially shortening the closure member, as is
discussed further below. In yet a further embodiment, expansion of
the device may be accomplished by torque rods, as discussed
previously with reference to FIGS. 11A-B. The proximal hub 614 may
threadingly engage the torque rod such that rotation of the torque
rod will expand or contract the device 600. The distal hub 616 may
operate to support the distal end of the torque rod, permitting the
torque rod to rotate freely upon its axis with the distal hub 616.
In another embodiment, the distal hub 616 may also be threadingly
engaged to the torque rod.
[0168] For deployment, the device 600 is preferably advanced
through the channel 122 of the patent foramen ovale 120 until the
distal end of the catheter is beyond the tip 130 of the septum
primum 116. The device 600 is preferably advanced until the distal
end 616 of the device 600 extends into the left atrium 104. The
distal segment 622 is exposed from the catheter, such that it
expands to its enlarged, implantation cross-section and engages the
septum primum 116 wall on the left atrium 104 side. The device 600
then is then drawn proximally to draw the septum primum 116 toward
the septum secundum 118, closing the channel 122. The proximal
segment 620 of the device 600 is then exposed and permitted to
expand to its enlarged, implantation cross-section, securing the
septum secundum 118 to the septum primum 116.
[0169] Depending upon the desired introduction crossing profile of
the collapsed closure device 600, as well as structural strength
requirements in the deployed device, anywhere within the range of
from about 3 spokes to about 40 spokes may be utilized. In some
embodiments, anywhere from about 12 to about 24 spokes are
utilized, and 18 spokes are utilized in one embodiment.
[0170] Preferably, the spokes comprise a metal such as stainless
steel, Nitinol, Elgiloy, or others which can be determined through
routine experimentation by those of skill in the art. Wires having
a circular or rectangular cross-section may be utilized depending
upon the manufacturing technique. In one embodiment, rectangular
cross section spokes are cut such as by known laser cutting
techniques from tube stock, a portion of which forms the hubs 614,
616, 618.
[0171] The barrier 606 may comprise any of a variety of materials
which facilitate cellular in-growth, such as ePTFE. The suitability
of alternate materials for barrier 606 can be determined through
routine experimentation by those of skill in the art. The barrier
606 may be provided on either one or preferably both axially facing
sides of the closure member. In one embodiment, the barrier 606
comprises two layers, with one layer on each side of the frame 604.
The two layers may be bonded to each other around the spokes 608 in
any of a variety of ways, such as by heat bonding with or without
an intermediate bonding layer such as polyethylene or FEP,
adhesives, sutures, and other techniques which will be apparent to
those of skill in the art in view of the disclosure herein. The
barrier 606 preferably has a thickness of no more than about 0.003
in.
[0172] For use in a patent foramen ovale, the occluding member 600
has an expanded diameter within the range of from about 10 mm to
about 40 mm, and, in one embodiment, about 20 mm. The overall
length of the closure device 600 from the distal end 612 to the
distal end 610 is within the range of from about 40 mm to about 100
mm and, in one embodiment, about 70 mm.
[0173] Modifications to the closure device are illustrated in FIGS.
35-36. The closure device 650 comprises a closure member 652
comprising a frame 654 and a barrier 656. In the illustrated
embodiment the frame 654 comprises a plurality of radially
outwardly extending spokes 658. The device has a proximal end 660
and a distal end 662, corresponding to a proximal hub 664 and a
distal hub 666. A central hub 668 is also preferably provided
between the proximal hub 664 and distal hub 666. The frame 654 and
barrier 656 form a proximal segment 670 and a distal segment 672.
The designation proximal or distal is not intended to indicate any
particular anatomical orientation or deployment orientation within
the deployment catheter. Proximal and distal segments 670, 672 are
concave faced baskets, which secure the septum primum and septum
secundum on both sides, thus sealing the patent foramen ovale.
Deployment of the device 650 preferably corresponds to the
deployment discussed above with reference to FIGS. 33-34.
[0174] Referring to FIGS. 37 and 38A-B, a further variation of the
closure device is shown. The closure device 700 comprises a closure
member 702 comprising a frame 704 and a barrier 706. In one
embodiment, the frame 704 comprises a plurality of radially
outwardly extending supports (not shown). The device has a proximal
end 710 and a distal end 712 corresponding to a proximal hub 714
and a distal hub 716. A soft distal tip 718 is also preferably
provided at the distal end 712, and is connected to distal hub 716.
The frame 704 and barrier 706 form a proximal segment 720 and a
distal segment 722. The designation proximal or distal is not
intended to indicate any particular anatomical orientation or
deployment orientation within the deployment catheter. Proximal and
distal segments 720, 722 behave like baskets to secure the septum
primum and septum secundum on both sides, thus sealing the patent
foramen ovale.
[0175] With reference to FIG. 38A, the device is shown in an
unexpanded state. Proximal retraction on the deployment line 730
while resisting proximal movement of proximal hub 714 such as by
using the distal end of the catheter 732 will cause the distal hub
716 to be drawn towards the proximal hub 714, thereby radially
enlarging the cross-sectional area of the closure device 700, as
shown in FIG. 38B. Depending upon the material utilized for the
closure device 700, the supports 708 will retain the radially
enlarged orientation by elastic deformation, or may be retained in
the enlarged orientation such as by securing a slip knot immovably
to the deployment line 730 at the fully radially enlarged
orientation. This may be accomplished in any of a variety of ways,
using additional knots, clips, adhesives, or other techniques known
in the art. A variety of alternative structures may be utilized, to
open or enlarge the closure device 700 under positive force, such
as using a pullwire or a torque element, as will be discussed in
further detail hereinafter. Deployment of the device 700 preferably
corresponds to the deployment discussed above with reference to
FIGS. 33-34.
[0176] With reference to FIGS. 39-41, the closure device 750
comprises an occluding member 752 comprising a frame 754 and a
barrier 756. In the illustrated embodiment the frame 754 comprises
a plurality of radially outwardly extending spokes 758. The device
has a proximal end 760 a distal end 762 corresponding to a proximal
hub 764 and a distal hub 766. A central hub 768 is also preferably
provided between the proximal hub 764 and distal hub 766. A soft
distal tip 769 is also preferably provided at the distal end 762,
and is connected to distal hub 766. The frame 754 and barrier 756
form a proximal segment 770 and a distal segment 772. The
designation proximal or distal is not intended to indicate any
particular anatomical orientation or deployment orientation within
the deployment catheter. Proximal and distal segments 770, 772 are
umbrellas which secure the septum primum and septum secundum on
both sides, sealing the patent foramen ovale. The proximal and
distal segments 770, 772 have a generally concave inwardly facing
surface 774 and convex outwardly facing surface 776. The device is
shown in a collapsed state in FIG. 41. Deployment of the device 750
preferably corresponds to the deployment discussed above with
reference to FIGS. 33-34.
[0177] Referring to FIGS. 42-43 and 45, a variation of the closure
device is shown. The closure device 800 comprises a frame 804 and a
barrier 806. In the illustrated embodiment the frame 804 comprises
a plurality of radially outwardly extending spokes 808. The device
has a proximal end 810 a distal end 812 corresponding to a proximal
hub 814 and a distal hub 816. The frame 804 and barrier 806 form a
proximal segment 820 and a distal segment 822. The designation
proximal or distal is not intended to indicate any particular
anatomical orientation or deployment orientation within the
deployment catheter. Proximal and distal segments 820, 822 are
umbrellas which secure the septum primum and septum secundum on
both sides, thus sealing the patent foramen ovale. The proximal and
distal segments 820, 822 have a generally flat inwardly facing
surface 824 and an angled outwardly facing surface 826. The device
800 is shown in a collapsed position in FIG. 45. Deployment of the
device 800 preferably corresponds to the deployment discussed above
with reference to FIGS. 33-34.
[0178] Referring to FIGS. 44A-C, a closure device 1400 is
preferably positioned within a septal defect to be occluded, such
as a patent foramen ovale or an atrial septal defect. In a patent
foramen ovale application, the distal end 1402 of the delivery
catheter 1404 is positioned at or near the patent foramen ovale
120. The position may be confirmed using fluoroscopy,
echocardiography, or other imaging. The device 1400 is initially in
a collapsed state in catheter 1404. The actuator 1408 (shown in
FIG. 44C) is thereafter proximally retracted or rotated, as with a
torque rod, to place and expand the closure device 1400 at the
patent foramen ovale 120.
[0179] As will be apparent from FIG. 44B, proximal retraction or
rotation on the actuator 1408 while resisting proximal movement of
proximal hub 1410 such as by using the distal end of the catheter
1404 will cause the distal hub 1412 to be drawn towards the
proximal hub 1410. The closure device 1400 engages the septa walls
thereby closing the patent foramen ovale.
[0180] The actuator may then be locked with respect to the proximal
hub and severed or otherwise detached to enable removal of the
deployment catheter and proximal extension of the actuator. Locking
of the actuator 1408 with respect to the closure device 1400 may be
accomplished in a variety of ways, such as by using interference
fit or friction fit structures, adhesives, a knot or other
techniques depending upon the desired catheter design, as discussed
herein. After the device 1400 is locked in placed, the catheter
1402 is detached from the device 1400 and removed from the patient.
See FIG. 44. The device 1400 can also be captured and retrieved at
any time during the procedure as long as it is not detached from
the delivery catheter.
[0181] With reference to FIG. 46, an alternative embodiment of the
closure device is shown. The closure device 850 comprises a
proximal inflatable balloon 852 and a distal inflatable balloon 854
joined together at a central hub 856. The device 850 may also
comprise a frame, comprising a plurality of supports. The device
850 is preferably expanded by inflating the balloons 852, 854 via
an inflation catheter by inserting inflation fluid through
inflation lumen 858. The central hub 856 is positioned within the
patent foramen ovale, while the proximal balloon 852 is preferably
positioned in the right atrium and the distal balloon 854 is
positioned in the left atrium, to occlude the patent foramen
ovale.
[0182] Any modifications to the device to accommodate these various
aspects of the closure device as discussed herein may be readily
accomplished by those of skill in the art in view of the disclosure
herein.
[0183] Tack Embodiments
[0184] With reference to FIGS. 47 and 48, alternative embodiments
are shown. In these embodiments, the patent foramen ovale is simply
held together by positioning a device 900, 950 to hold the septum
primum 116 and septum secundum 118 together. In a first embodiment,
the device 900 comprises a proximal end 906 and a distal end 908,
having a proximal anchor 910 and a distal anchor 912.
Alternatively, a device 950 comprises a proximal end 956 and a
distal end 958. The device has a screw-like configuration and
comprises a coiled wire or threaded screw 960. The proximal end
906, 956 is preferably positioned in the right atrium, while the
distal end 908, 958 is positioned in the left atrium. The device
900, 950 includes a detachment zone 914, 964. The device may also
be provided with a sleeve, as has been discussed with previous
embodiments.
[0185] Preferably, the device 900, 950 is formed of a metal such as
stainless steel, Nitinol, Elgiloy, or others which can be
determined through routine experimentation by those of skill in the
art. The wire may also be biodegradable. Wires having a circular or
rectangular cross-section may be utilized depending upon the
manufacturing technique. In one embodiment, a circular cross
section wire is cut such as by known laser cutting techniques from
tube stock. The closure device is preferably an integral structure,
such as a single ribbon or wire, or element cut from a tube
stock.
[0186] In another preferred embodiment, with reference to FIGS.
49-51, a closure device 1000 comprising a closure member is shown.
The device comprises a proximal end 1002 and a distal end 1004, and
a circular proximal section 1006 and circular distal section 1008,
which are connected via a center strut 1010, forming an integral
structure. The center strut 1010 preferably contains a closure or
thrombotic material 1011. A loop 1012 is provided for holding and
retrieving the device 1000. The proximal and distal sections 1006,
1008 act like springs, and maintain stability and help to squeeze
the patent foramen ovale.
[0187] The center strut 1010 rests within the patent foramen ovale
120 for occluding the channel 122, engaging the septum primum 116
and the septum secundum 118. The proximal section 1006 is
preferably positioned in the right atrium, while the distal section
1008 is positioned in the left atrium.
[0188] Preferably, the device 1000 is formed of a metal such as
stainless steel, Nitinol, Elgiloy, or others which can be
determined through routine experimentation by those of skill in the
art. The wire may also be biodegradable. Wires having a circular or
rectangular cross-section may be utilized depending upon the
manufacturing technique. In one embodiment, a circular cross
section wire is cut such as by known laser cutting techniques from
tube stock. The closure device is preferably an integral structure,
such as a single ribbon or wire, or element cut from a tube
stock.
[0189] The thrombotic material 1011 may include DACRON.TM., or
others which can be determined through routine experimentation by
those of skill in the art.
[0190] Channel-Filling Embodiments
[0191] With reference to FIG. 52, there is illustrated another
preferred embodiment of the present invention. A closure device
1050 comprising a porous sponge or sponge-like material is shown.
Alternatively, the closure device 1050 may comprise a fluid-filled
bag with a porous or semi-porous other covering. In some
embodiments, the closure device 1050 has a generally cylindrical
shape. In some embodiments, the sponge is at least as large as the
defect to be filled. In some embodiments, tether 1055 extends
through closure device 1050 and is used to attach closure device
1050 to delivery catheter 1504. FIG. 53 illustrates the sponge-like
closure device 1050 positioned at a patent foramen ovale. The
sponge expands upon placement to close the defect and is secured in
place by the septum primum 116 and septum secundum 118.
[0192] In some embodiments, the sponge or sponge-like material may
comprise collagen, PE, PTFE, Poly Vinyl Acetate (Ivalon), or Ethyl
Vinyl Acetate. In some embodiments, the material may be
bioresorbable. In some embodiments, the sponge promotes tissue
ingrowth for more complete sealing of a septal defect, such as a
patent foramen ovale.
[0193] With reference to FIG. 54, an anchor device 1060 is
illustrated. The anchor device 1060 comprises a frame 1062 having a
plurality of retention elements 1064 provided thereon. In some
embodiments, the frame may be perforated, while in other
embodiments, the frame is solid.
[0194] In some embodiments, the anchor device 1060 may be comprised
of a plurality of laser cut strips 1065, as shown in FIG. 55. The
laser cut strips comprise a laser-cut body 1066 which can be
twisted to reveal anchors 1068. A detailed view of the body 1066
and anchors 1068 is shown in FIG. 56. By linking together a
plurality of the laser cut strips 1065, a lattice of anchoring
surfaces can be formed. The lattice of anchoring surfaces can also
be placed within or through a patent foramen ovale.
[0195] As shown in FIG. 57, the anchor device 1060 may be used with
the sponge-like closure device 1050 to form an anchored sponge
closure device 1070. The anchors may be used to further secure the
sponge-like closure device in place. FIG. 58 illustrates closure
device 1070, wherein anchor devices 1060 secure the sponge-like
closure device 1050 at a defect.
[0196] Referring to FIG. 59A-C, a preferably method is shown of
deploying the closure device 1500 within a septal defect, such as a
patent foramen ovale. In a patent foramen ovale application, the
distal end 1502 of the delivery catheter 1504 is positioned at or
near the patent foramen ovale 120, as shown in FIG. 59A. The
position may be confirmed using fluoroscopy, echocardiography, or
other imaging. The device 1500 is initially in a collapsed state
within catheter 1504. The device 1500 may be releasably attached to
an actuator 1508. The distal end 1502 of the delivery catheter 1504
is advanced between the septum primum 116 and septum secundum 118
as shown, and the posterior portion 1510 is advanced out of the
distal end 1502 of the delivery catheter 1504, as shown in FIG.
59B. The intermediate section and posterior sections are then
delivered, as shown in FIG. 59C. After optimal positioning and
sealing is achieved, the device 1500 can then be detached from the
delivery catheter 1504.
[0197] Any of the closure devices disclosed herein may also be
coated with a therapeutic substance, such as an anti-thrombogenic
drug. The therapeutic substances are typically either impregnated
into the device or carried in a polymer that coats the device. The
therapeutic substances are released from the device or polymer once
it has been implanted in the vessel. The device may be impregnated
with at least one drug or coated with at least one drug by any
known process in the art. The drug may be carried in a volatile or
non-volatile solution. As used in this application, the term "drug"
denotes any compound which has a desired pharmacological effect, or
which is used for diagnostic purposes.
[0198] Furthermore, the closure devices as disclosed herein are
preferably asymmetrical. As has been discussed, the axis of a
patent foramen ovale tends to be at an angle, and almost parallel
to the septal wall. Accordingly, asymmetrical closure devices will
be effective in closing septal defects having non-longitudinal
axes, such as a patent foramen ovale.
[0199] As a post implantation step for any of the closure devices
disclosed herein, a radiopaque dye or other visualizable media may
be introduced on one side or the other of the closure device, to
permit visualization of any escaped blood or other fluid past the
closure device. For example, in the context of a patent foramen
ovale application, the closure device may be provided with a
central lumen or other capillary tube or aperture which permits
introduction of a visualizable dye from the deployment catheter
through the closure device and into the space on the distal side of
the closure device.
[0200] While particular forms of the invention have been described,
it will be apparent that various modifications can be made without
departing from the spirit and scope of the invention. Accordingly,
it is not intended that the invention be limited, except as by the
appended claims.
* * * * *