U.S. patent application number 11/635095 was filed with the patent office on 2008-03-13 for expandable clip for tissue repair.
Invention is credited to Richard B. Cates, David L. Hauser, Rafael Pintor, Stanton J. Rowe.
Application Number | 20080065156 11/635095 |
Document ID | / |
Family ID | 39170755 |
Filed Date | 2008-03-13 |
United States Patent
Application |
20080065156 |
Kind Code |
A1 |
Hauser; David L. ; et
al. |
March 13, 2008 |
Expandable clip for tissue repair
Abstract
An apparatus, system, and method for repairing openings such as
septal defects includes advancing a catheter to the site of the
defect, grasping opposing edges of the defect, passing one or more
suture lines through the opposing edges, tightening the suture
lines, and deploying and expanding a fastener to secure the suture
lines and close the defect. The fastener can include
tissue-growth-inducing materials to encourage tissue growth onto or
into the fastener and/or suture. The fastener includes a locking
clip portion and a plug portion, which may be an expandable portion
and/or tissue-growth-inducing portion.
Inventors: |
Hauser; David L.; (Newport
Beach, CA) ; Cates; Richard B.; (Manhattan Beach,
CA) ; Pintor; Rafael; (Mission Viejo, CA) ;
Rowe; Stanton J.; (Newport Beach, CA) |
Correspondence
Address: |
EDWARDS LIFESCIENCES CORPORATION
LEGAL DEPARTMENT, ONE EDWARDS WAY
IRVINE
CA
92614
US
|
Family ID: |
39170755 |
Appl. No.: |
11/635095 |
Filed: |
December 7, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60843267 |
Sep 8, 2006 |
|
|
|
Current U.S.
Class: |
606/232 |
Current CPC
Class: |
A61B 2017/0488 20130101;
A61B 2017/00575 20130101; A61B 2017/0464 20130101; A61B 17/0487
20130101; A61B 2017/0496 20130101; A61B 2017/00243 20130101; A61B
2017/0061 20130101; A61B 2017/0445 20130101; A61B 2017/0456
20130101; A61B 2017/00654 20130101; A61B 17/0469 20130101; A61B
17/06166 20130101; A61B 17/0483 20130101; A61B 17/0057 20130101;
A61B 17/0482 20130101 |
Class at
Publication: |
606/232 |
International
Class: |
A61B 17/04 20060101
A61B017/04 |
Claims
1. A system for percutaneously treating tissue at a treatment site
within a patient's body, comprising: a closure device comprising a
suture-locking portion and a plug portion, wherein the closure
device is configured to be slidably positioned over at least one
line of suture; and at least one closure catheter configured to
percutaneously deliver the closure device over the at least one
line of suture and to the treatment site.
2. The system of claim 1, wherein the plug portion is expandable
from a first diameter to a second diameter.
3. The system of claim 2, wherein the closure catheter is
configured to expand the plug portion from the first diameter to
the second diameter.
4. The system of claim 3, wherein the plug portion is
self-expanding, and the closure catheter is configured to forcibly
restrain the plug in the first diameter, and the closure catheter
is further configured to release the plug to expand to the second
diameter.
5. The system of claim 1, wherein the closure catheter is
configured to lock the suture-locking portion to the at least one
line of suture at a position adjacent the treatment site.
6. The system of claim 1, wherein the closure catheter comprises an
outer sheath, and the closure device is positioned within the outer
sheath.
7. The system of claim 1, further comprising: a suture catheter
configured to deliver the at least one line of suture through
tissue at the treatment site.
8. An assembly for percutaneously treating tissue at a selected
treatment site in a patient's body, comprising: at least one line
of suture, the at least one line of suture having a first end
secured at or adjacent the selected treatment site and a second end
positioned outside the patient's body; and a treatment device, the
treatment device comprising a plug portion and suture-locking
portion, wherein the treatment device includes a suture opening
configured to receive the at least one line of suture, and the
treatment device is configured to be percutaneously advanced over
the at least one line of suture to the treatment site.
9. The assembly of claim 8, wherein the plug portion is expandable
from a first diameter to a second diameter.
10. The assembly of claim 9, wherein the plug portion comprises a
self-expanding structure.
11. The assembly of claim 9, wherein the plug portion comprises a
bioresorbable material.
12. The assembly of claim 8, wherein the plug portion comprises a
tissue-growth-inducing material.
13. The assembly of claim 8, wherein the suture-locking portion and
the plug portion are integral portions of a single piece treatment
device.
14. The assembly of claim 8, wherein the at least one line of
suture comprises tissue-growth-inducing material.
15. A device for percutaneously locking suture adjacent a treatment
site, the device comprising: a suture-locking portion, the
suture-locking portion comprising a suture opening configured to
slidingly receive at least one line of suture, and a lock
configured to prevent suture from sliding through the suture
opening; and a plug portion secured to the suture-locking
portion.
16. The device of claim 15, wherein the plug portion is configured
to expand from a first diameter to a second diameter.
17. The device of claim 15, wherein the plug portion comprises a
self-expanding structure.
18. The device of claim 15, wherein the plug portion is configured
to be positioned within a PFO.
19. The device of claim 15, wherein the plug portion comprises
tissue-growth-inducing material.
20. The device of claim 15, wherein plug portion comprises an
expandable foam-like material.
21. The device of claim 15, wherein the plug portion comprises a
generally flattened surface configured to be placed against a first
side of a septal defect.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application No. 60/843,267, filed on Sep. 8, 2006, the
disclosure of which is incorporated by reference herein in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to medical devices and
methods. In particular, the present invention relates to a system,
apparatus, and method for repairing tissue, and particularly for
repairing septal defects, such as a patent foramen ovale (PFO).
BACKGROUND OF THE INVENTION
[0003] Septal defects are a relatively common occurrence. While
many septal defects are relatively benign and have little or no
impact on a person's health, other septal defects can be more
serious.
[0004] One type of septal defect is a patent foramen ovale (PFO),
which is an opening between the right atrium and the left atrium.
Because the fetal lungs do not provide air prior to birth, fetal
blood is oxygenated by the mother via the umbilical cord and
placentia. To provide for such circulation, the fetal blood
circulation system includes several vessels and openings that
remain open during fetal development but that close soon after
birth. One such opening is the foramen ovale, which permits blood
to flow from the right atrium into the left atrium in a fetal
heart, thereby allowing blood to bypass the fetal lungs and flow
directly from the venous circulation to the arterial
circulation.
[0005] After birth, the infant's lungs typically provide
oxygenation to the blood, and it is generally undesirable to
continue having blood flow from the venous circulation to the
arterial circulation without first passing through the lungs.
Accordingly, it is generally desirable that the foramen ovale be
closed after birth.
[0006] At birth, left atrial pressure increases as the pulmonary
circulation is established. For most newborn infants, this pressure
increase causes the closure of a flap of tissue which occludes the
foramen ovale and then heals in the occluded position shortly after
birth. In a significant percentage of persons, however, the tissue
flap does not heal to permanently occlude the foreman ovale. This
condition is known as a patent (i.e., open) foramen ovale
(PFO).
[0007] While a PFO can be a relatively benign condition, PFOs have
been associated with migraines. PFOs can also cause strokes by
permitting blood containing small thrombi to bypass the lungs
(which would otherwise filter out such small thrombi) and flow
directly from the venous circulation to the arterial circulation
and into the brain.
[0008] Treatments for PFOs range from open-heart surgery to
percutaneous procedures. Open-heart surgery for PFOs typically
involves suturing the PFO closed. Although relatively simple, such
open-heart surgical treatment is associated with all the usual
risks of cardiac surgery. Percutaneous methods include deploying
mesh, clamshell, or other similar implanted devices to close the
PFO. Other treatments include using heat, laser, RF, or other
energy to treat the tissue of (or adjacent to) the PFO to induce
the tissue to permanently close the PFO. Many of these percutaneous
methods are often complicated and may involve relatively large
implanted devices or uncertain tissue treatments.
[0009] One particularly effective method for repairing a PFO
involves the percutaneous introduction of a catheter having a
needle and suture assembly, with the suture percutaneously passed,
via one or more needles deployed via the catheter, through the
tissue surrounding the PFO. The catheter is withdrawn and the user
tightens the suture to assess whether the suture has been deployed
to properly close the PFO. The suture is then secured via tying or
clipping, and the excess suture is cut and removed. The PFO is thus
held closed by the tightened suture. Such a method and apparatus is
disclosed in co-pending U.S. patent application Ser. No.
11/174,143, filed Jun. 30, 2005, the entire contents of which are
expressly incorporated herein by reference. Other methods, systems,
and devices for deploying suture that may be applicable for use
with the current invention are disclosed in Applicant's U.S. Pat.
Nos. 6,537,290; 6,626,930; 6,860,890; 6,719,767; 7,011,669;
7,083,628; and 7,094,244; and also in Applicant's co-pending U.S.
application Ser. Nos. 10/233,879 and 10/389,721; the contents of
each of which are incorporated in entirety herein by reference.
[0010] In light of the foregoing, there is presently a need for
improved systems for treating PFOs. More specifically, there is a
present need for an improved method, apparatus, and system for
repairing PFOs. The current invention meets this need.
BRIEF SUMMARY OF THE INVENTION
[0011] Embodiments of the present invention provide devices and
methods for effectively treating a tissue opening, such as a PFO or
other septal defect, and particularly for effectively treating an
opening that may be unsuitable for closure using suture alone.
Preferred embodiments of the invention provide devices and methods
wherein a PFO is treated via a catheter from a remote insertion
location.
[0012] In one aspect, the present invention is a suture-securing
fastener or clip, similar to earlier suture-securing clips used in
percutaneous edge-to-edge heart valve leaflet repairs and PFO
closures except that the current fastener is expandable upon
delivery so that the clip itself serves to physically block the
opening which the procedure is attempting to close. The clip serves
as a closure and/or treatment device. The clip has a center
suture-receiving lumen so that the clip can be advanced into the
patient's body to the desired treatment site by being slid along
one or more suture lines previously deployed, with the one or more
suture lines passing from the desired treatment site to a position
outside of the patient's body. The suture line thus acts, during
clip delivery and deployment, as a guide for proper placement of
the clip. Once the clip is at the desired treatment site (which is
typically at or adjacent the opening to be closed) and the suture
is tightened as desired, the clip locks onto the suture (via a
locking clip portion) to hold the suture and clip securely in
position. The clip is then expanded to its expanded configuration
in order to physically block the opening that is being closed, so
that the expandable portion of the clip serves as a plug portion.
Alternatively, the expandable plug portion of the clip can be
expanded prior to being locked into place on the suture, so that
the user can check the positioning of the clip and the efficacy of
the blockage created thereby, and the clip can then be locked
securely onto the suture line to hold the clip and suture in the
desired location and positioning. The expansion and locking of the
clip can also occur as a single step, depending on the particular
application and clip configuration. If the desired closure is not
achieved, the expanded clip can be retrieved into its protective
sheath (which can involve de-expanding the clip), the catheter
removed, and the procedure aborted. The suture lines can then be
removed and/or additional attempts can be made to perform the
procedure, which may include using one or more different clips
and/or different suture lines.
[0013] The expandable clip can expand mechanically once it is
positioned at the desired treatment site. The expansion could be
achieved by a generally umbrella-shaped structure, an inflatable
structure, an expandable cage-like structure, and/or other
configurations. The expandable clip could include an expandable
sponge-like, foam-like, and/or adhesive-like material, which could
expand from or around the clip. The expansion could be activated by
the user, or be an inherent quality of the clip when exposed to the
interior environment of the patient's body (e.g., an expandable
sponge-like material that expands when exposed to blood and/or
other body fluids). The expandable clip may include additional
structures to hold the clip in place, such as tissue-penetrating
spikes, etc. The clip may be configured to encourage tissue
ingrowth onto or into the clip, which may include providing one or
more tissue-growth-inducing material in the clip. In some
applications, such as where a blockage is desired to be temporary,
the clip may be configured to discourage tissue ingrowth so that
the clip can be removed later. The clip may be configured to be
reduced in diameter after it has been expanded to its deployed
size, so that a user can reposition and/or remove the clip after it
has been initially expanded within the patient's body.
[0014] In one aspect, the present invention is directed to a system
and method for repairing a PFO with a treatment catheter capable of
applying at least one suture to the tissue adjacent the PFO. The
invention can further use a fastener catheter capable of attaching
at least one fastener to the suture. In addition, the fastener
catheter can include at least one cutting member configured to cut
the suture to a desired length. The fastener of the invention can
be configured so that it expands upon deployment, so that the bulk
of the expanded fastener itself helps to close the septal
defect.
[0015] In another aspect, the present invention includes a system
and method for repairing a PFO using a fastener and patch
combination. The fastener and patch can be deployed separately,
e.g., by separate catheters, or together, e.g., by a single
catheter. In one such embodiment, a system for repairing a PFO and
includes a treatment catheter capable of applying at least one
suture to the tissue adjacent the PFO, and a fastener catheter
capable of attaching at least one fastener and a patch to the
suture. The patch is positioned distally of the fastener, so that
when the fastener is advanced into the patient, the patch is also
advanced to the PFO site. With the patch and fastener advanced to
the PFO, the user can determine the adequateness of the PFO
closure, and deploy the fastener to hold the suture tight and also
to hold the patch in place or, if the PFO closure is inadequate,
the user can remove the patch, fastener, and/or suture lines and
either abandon the repair attempt or retry using one or more
different patches, fasteners, and/or suture lines. If the user
completes the deployment of the fastener and patch, the patch will
be positioned between the fastener clip and tissue through which
the suture has passed, and the patch is thus held (by the fastener)
against and/or within the PFO to effectuate the PFO closure.
[0016] In yet another aspect, the present invention discloses a
system for repairing tissue within the heart of a patient and
includes a guide wire capable of being inserted into the patient
and advanced through a circulatory pathway, a treatment catheter
attachable to the guide wire and capable of applying at least one
suture to the tissue, and fastener catheter attachable to the guide
wire and capable of attaching at least one fastener to the suture,
and a fastener configured to expand upon deployment. A patch may
also be included with a system and method. The patch may be used
with the expandable fastener, or with a non-expandable fastener.
The patch may be deployed with or separately from the fastener.
[0017] In another embodiment of the invention, tissue-irritating
materials are used to speed the healing process whereby the tissue
adjacent the PFO grows over the suture, fastener, and/or patch. The
fastener may include tissue-irritating materials in its structure,
including tissue-irritating materials in the expandable portion of
the fastener. The patch may also include tissue-irritating
materials, such as tissue-irritating cloth. In a further
embodiment, the suture has enhanced tissue-irritating
characteristics.
[0018] The present invention also discloses various methods of
treating a PFO within the body of a patient. In one aspect, a
method of treating a PFO is disclosed which includes advancing a
guide catheter through a circulatory pathway to a location in the
heart proximate to a PFO, advancing a PFO treatment catheter
through the guide catheter to the PFO, deploying a first suture
into the stabilized first adjacent tissue portion, deploying a
second suture into the second adjacent tissue portion, reducing the
distance between the first and second sutures, advancing an
expandable clip along the first and second sutures to the PFO,
expanding the expandable clip adjacent or within the PFO, assessing
the efficacy of the PFO repair, and deploying the expandable clip
adjacent or within the PFO. The method may also include stabilizing
the first and second adjacent tissue portions, which may be
performed by applying a vacuum. The vacuum may first be applied to
stabilizing a first adjacent tissue portion with the treatment
catheter, then removed to release the first adjacent tissue
portion, followed by application of the vacuum to stabilize the
second tissue portion, then removed to release the second adjacent
tissue portion.
[0019] An alternate method of treating a PFO is disclosed and
comprises advancing a guide catheter through a circulatory pathway
to a location in the heart proximate the PFO, advancing a PFO
treatment catheter through the guide catheter to the PFO, deploying
a first suture into the stabilized first adjacent tissue portion,
deploying a second suture into the second adjacent tissue portion,
advancing a patch over the first and second sutures to a position
adjacent or within the PFO, advancing a fastener over the first and
second suture to a position adjacent or within the PFO, tightening
the first and second sutures, assessing the efficacy of the PFO
closure, and deploying the fastener. The method may also include
expanding the fastener adjacent to or within the PFO.
[0020] Other objects, features, and advantages of the present
invention will become apparent from a consideration of the
following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1A illustrates a suture-deploying treatment catheter
advanced within a patient's vasculature and into a PFO according to
an embodiment of the invention;
[0022] FIG. 1B illustrates a close-up of the suture-deploying
treatment catheter of FIG. 1B deploying a first suture through a
first tissue portion adjacent the PFO according to an embodiment of
the invention;
[0023] FIG. 1C illustrates a close-up of the suture-deploying
treatment catheter of FIG. 1B deploying a second suture through a
second tissue portion adjacent the PFO according to an embodiment
of the invention;
[0024] FIG. 1D illustrates the suture-deploying treatment catheter
being withdrawn from the patient's vasculature, trailing the first
and second suture lines behind according to an embodiment of the
invention;
[0025] FIG. 2A illustrates a fastener-deploying catheter being
advanced within a patient's vasculature over the first and second
suture lines and into the PFO according to an embodiment of the
invention;
[0026] FIG. 2B depicts a close-up side view of the
fastener-deploying catheter advanced within the PFO, with the
fastener positioned within the PFO;
[0027] FIG. 2C depicts a close-up side view of the
fastener-deploying catheter advanced within the PFO, with the
fastener expanded and deployed to secure the first and second
suture lines within the PFO;
[0028] FIG. 2D depicts the a close-up side view of the PFO, with
the excess suture cut from the first and second sutures;
[0029] FIGS. 3A, 3B, and 3C depict perspective, end, and side (with
partial cross section) views, respectively, of a fastener in the
unexpanded condition according to an embodiment of the
invention;
[0030] FIGS. 3D, 3E, and 3F depict perspective, end, and side (with
partial cross section) views, respectively, of the fastener from
FIGS. 3A, 3B, and 3C in the expanded condition according to an
embodiment of the invention;
[0031] FIGS. 4A through 4D depict side views of a fastener being
deployed from a catheter according to an embodiment of the
invention;
[0032] FIGS. 5A and 5B depict end and side (with partial cross
section) views, respectively, of a fastener in the unexpanded
condition according to an embodiment of the invention;
[0033] FIGS. 5C, 5D, and 5E depict perspective, end, and side (with
partial cross section) views, respectively, of a fastener from
FIGS. 5A and 5B in the expanded condition according to an
embodiment of the invention;
[0034] FIGS. 6A and 6B depict end and side (with partial cross
section) views, respectively, of a fastener in the expanded
condition according to an embodiment of the invention;
[0035] FIG. 6C depicts a side view, in cross section, of the
fastener of FIGS. 6A and 6B being deployed from a catheter
according to an embodiment of the invention;
[0036] FIGS. 6D and 6E depict end and side (with partial cross
section) views, respectively, of the fastener from FIGS. 6A and 6B
in the expanded condition according to an embodiment of the
invention;
[0037] FIG. 7A depicts a side view in cross section of a fastener
according to an embodiment of the invention;
[0038] FIG. 7B depicts a side view in cross section of a fastener
according to an embodiment of the invention;
[0039] FIGS. 8A, 8B, and 8C depict perspective, end, and side (with
partial cross section) views, respectively, of a fastener in the
unexpanded condition according to an embodiment of the
invention;
[0040] FIGS. 8D, 8E, and 8F depict perspective, end, and side (with
partial cross section) views, respectively, of the fastener from
FIGS. 8A, 8B, and 8C in the expanded condition according to an
embodiment of the invention;
[0041] FIGS. 9A, 9B, and 9C depict end, side, and top views,
respectively, of a fastener in the unexpanded condition according
to an embodiment of the invention;
[0042] FIGS. 9D, 9E, 9F, and 9G depict perspective, side, end, and
top views, respectively, of the fastener from FIGS. 9A, 9B, and 9C
in the expanded condition according to an embodiment of the
invention;
[0043] FIGS. 10A and 10B depict end and side views, respectively,
of a fastener in the unexpanded condition according to an
embodiment of the invention;
[0044] FIGS. 10C and 10D depict end and side views, respectively,
of the fastener from FIGS. 10A and 10B in the expanded condition
according to an embodiment of the invention;
[0045] FIGS. 11A and 11B depict end and side views, respectively,
of a fastener in the expanded condition according to an embodiment
of the invention;
[0046] FIG. 12 depicts a side view of a fastener in the expanded
condition according to an embodiment of the invention;
[0047] FIGS. 13A and 13B depict end and side views, respectively,
of a fastener in the unexpanded condition according to an
embodiment of the invention;
[0048] FIGS. 13C and 13D depict perspective and side views,
respectively, of the fastener of FIGS. 13A-13B in the expanded
condition according to an embodiment of the invention;
[0049] FIGS. 14A and 14B depict side and end views, respectively,
of a fastener in the unexpanded condition according to an
embodiment of the invention;
[0050] FIGS. 14C and 14D depict side and end views, respectively,
of the fastener of FIGS. 14A-14B in the expanded condition
according to an embodiment of the invention;
[0051] FIGS. 15A and 15B depict side and end views, respectively,
of a fastener in the unexpanded condition according to an
embodiment of the invention;
[0052] FIGS. 15C and 15D depict side and end views, respectively,
of the fastener of FIGS. 15A-15B in the expanded condition
according to an embodiment of the invention;
[0053] FIGS. 16A and 16B depict side and end views, respectively,
of a fastener in the unexpanded condition according to an
embodiment of the invention;
[0054] FIGS. 16C and 16D depict side and end views, respectively,
of the fastener of FIGS. 16A-16B in the expanded condition
according to an embodiment of the invention,
[0055] FIGS. 17A and 17B depict side and distal end views,
respectively, of a fastener in the unexpanded condition according
to an embodiment of the invention;
[0056] FIGS. 17C and 17D depict side and distal end views,
respectively, of the fastener from FIGS. 17A and 17B in the
expanded condition according to an embodiment of the invention;
[0057] FIGS. 18A and 18B depict side and distal end views,
respectively, of a fastener in the expanded condition according to
an embodiment of the invention;
[0058] FIGS. 19A and 19B depict side views of suture used to
securing tissue portions according to an embodiment of the
invention;
[0059] FIGS. 20A and 20B depict side views of one or more fasteners
used to secure tissue according to an embodiment of the
invention;
[0060] FIGS. 21A, 21B, and 21D depict side views of plugs and
fasteners used to secure tissue according to an embodiment of the
invention;
[0061] FIG. 21C depicts a front view of the plug from FIGS. 21B and
21D;
[0062] FIG. 22A depicts a side view of a fastener deployed within a
PFO according to an embodiment of the invention; and
[0063] FIG. 22B depicts a side view of a fastener deployed adjacent
a PFO according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0064] The invention is an apparatus, system, and method for
treating a patent foramen ovale (PFO) to cause closure thereof.
More specifically, the invention provides for percutaneous or other
minimally-invasive application of suture to PFO to cause closure of
the PFO.
[0065] FIG. 1A depicts a suture-deploying treatment catheter 10
according to the invention being advanced through a patient's
vasculature to a heart 12 and into a PFO 14. A guidewire 16 has
previously been advanced through the vasculature by passing up the
inferior vena cava 18, through the right atrium 20, and through the
PFO 14 and into the left atrium 22. Note that other introductory
routes, including other percutaneous and minimally invasive routes,
are also within the scope of the invention. For example, the
guidewire and device could be introduced through heart vessels
leading to the left ventricle 24 or right ventricle 26, and then on
to access the PFO 14 through either the right atrium 20 or left
atrium 22. Depending on the particular embodiment, the device may
also be introduced through the heart wall 28, as may be the case in
a minimally-invasive surgical procedure conducted through a
patient's chest cavity. The particular route selected for
introduction of the device to the PFO 14 depends on various
factors, including the condition of the patient. While the
embodiment of FIG. 1A includes a guidewire 16 to guide the
treatment catheter 10 into position, the guidewire 16 does not have
to be present in all embodiments, such as where the treatment
catheter 10 is steerable on its own to the PFO 14.
[0066] The treatment catheter 10 comprises a generally elongated
body 30 having a distal end 32 and a proximal end 34. A handle 36
is located at the proximal end 34. The treatment catheter 10 has
sufficient length to reach the PFO 14 from outside the patient's
body via the particular route selected. For a percutaneous route,
the treatment catheter will generally have a length on the order of
60 to 90 cm. Other access routes may require different lengths. The
elongated body 30 and distal end 32 have a diameter that is small
enough to pass through the particular blood vessels and/or openings
of the particular access route selected. While percutaneous
approaches through the inferior vena cava, as depicted in FIG. 1,
can accommodate diameters of 12 to 16 Fr for the treatment catheter
when used with an introducer sheath (which may have a diameter of
16 to 21 Fr depending on the particular application), other
approaches and/or omitting the introducer sheath may permit and/or
require delivery catheters having smaller or larger diameters.
[0067] The PFO is often a generally tunnel-shaped opening. In the
embodiment depicted, the treatment catheter distal end 32 is
positioned within the tunnel-like PFO. FIG. 1B depicts a close-up
view of the catheter distal end 32 positioned within the
tunnel-like PFO, between first and second tissue portions 38, 40,
which in the particular embodiment depicted are a septum primum and
septum secundum, respectively. Note that in most persons the septum
primum will have healed permanently to the septum secundum, thereby
permanently closing the foramen ovale. In a patient having a PFO,
however, the septum primum will not have healed in the closed
position, and instead acts a flap that only partially occludes
blood flow between the right and left atria.
[0068] In the embodiment of FIG. 1B, a vacuum recess 42 at the
catheter distal end 32 is generally crescent- or wedge-shaped in
profile. The vacuum recess 42 has been positioned adjacent the
first tissue portion 38, which has been drawn via the application
of vacuum into the vacuum recess 42. A first needle 44 attached to
a first suture line 46 is retracted proximally across the vacuum
recess 42 to pass through the first tissue portion 38, so that the
first suture line 46 is drawn through the first tissue portion
38.
[0069] Once the first needle 44 has been passed through the first
tissue portion 38, the first needle 44 is further retracted so that
it is entirely clear of the first tissue portion 38 and only the
first suture line 46 passes therethrough. The vacuum can then be
discontinued, so that the first tissue portion 38 is released from
the vacuum recess 42. The catheter distal end 42 and vacuum recess
42 can then be moved respectively away from the first tissue
portion 38 and toward the second tissue portion 40, with the first
suture line 46 playing out from the catheter distal end 32.
[0070] FIG. 1C depicts the catheter distal end 32 repositioned with
the vacuum recess 42 adjacent the second tissue portion 40, which
in the particular embodiment depicted involved rotating the
catheter distal end 32 by about 180 degrees. The second tissue
portion 40 has been drawn via the application of vacuum into the
vacuum recess 42. A second needle 48 attached to a second suture
line 50 has been passed through the second tissue portion 40,
drawing the second suture line 50 through the second tissue
portion.
[0071] Once the second needle 48 has been passed through the second
tissue portion 40, the second needle 48 is further retracted so
that it is entirely clear of the second tissue portion 40 and only
the second suture line 50 passes therethrough. The vacuum can then
be discontinued, so that the second tissue portion 40 is released
from the vacuum recess 42. The treatment catheter 10 can then be
withdrawn from the patient, as depicted in FIG. 1D. As the
treatment catheter 10 is withdrawn, the suture lines 46, 50 play
out from the treatment catheter 10. In the particular embodiment
depicted, the suture lines, 46, 50 meet at their distal ends and
connect to form one continuous length of suture 51.
[0072] FIGS. 1A-1D depict a treatment catheter having a single
vacuum port, two needles, and two lines of suture forming a single
common suture. However, other treatment catheters, needle
assemblies, and suture assemblies are also within the scope of the
invention. For example, a catheter having two or more vacuum ports
(or other tissue-stabilizing devices), with one or more needles and
sutures with each vacuum port, could be used. Such a catheter could
simultaneously grasp and/or suture both the first and the second
tissue portions. A treatment catheter having only a single needle
and suture could also be used with the invention, as could any
treatment catheter capable of delivering at least one line of
suture percutaneously through at least one tissue portion adjacent
the PFO (or other opening to be closed).
[0073] Note that it may be desirable in some applications that the
first and/or second tissue portions for suturing be selected from
well within the tunnel-like PFO, and/or within a distal (from the
user's viewpoint) portion of the tunnel-like PFO or other opening
to be treated. This will result in the suture lines passing through
tissue well within the PFO, so that any fastener subsequently
deployed on proximal portions of the suture lines can be deployed
well within the tunnel-like PFO. The selection of tissue for
suturing, however, depends on numerous factors, including the
particular PFO or other structure being occluded or treated, the
condition of the surrounding tissue, the particular fastener being
deployed, the likes and/or dislikes of a particular user, etc.
[0074] FIGS. 1A-1D depict two suture lines (which together form one
continuous suture line) being deployed through tissue at the
treatment site. However, other numbers of suture lines are also
within the scope of the invention. For example, multiple sutures
could be deployed in and/or around a treatment site to enhance the
closure of the final suture/fastener combination.
[0075] FIG. 2A depicts a fastener catheter 52 being advanced over
the suture lines 46, 50 within the patient's vasculature toward the
patient's heart 12 and the PFO 14. (Note that the guide wire has
been removed, with the suture lines 46, 50 now serving the catheter
guiding purpose formerly performed by the guide wire.
Alternatively, the guide wire could remain in place.) The fastener
catheter 52 includes a distal end 54 having a fastener 56 mounted
thereon, and a proximal end 58 having a handle 60. Trailing
portions 64, 66 of the suture lines 46, 50 pass outside of the
fastener catheter 52 through an opening therein just proximally of
the fastener catheter distal end 54 and then pass through the
patient's vasculature and outside of the patient. Note that
trailing suture portions could alternatively pass through the
length of a fastener catheter and exit out the proximal end thereof
in a manner similar to the way a guide wire passes through
so-called "over-the-wire" delivery catheters.
[0076] In FIG. 2B, the fastener catheter distal end 54 and fastener
56 have been advanced into the PFO 14, with the suture lines 46, 50
(which trail out of the opening 61 in the fastener catheter distal
end 54) tightened to draw the tissue portions 38, 40 together. With
the tissue portions 38, 40 drawn together, the user can confirm the
efficacy of the suture lines placement and/or PFO closure, which
can be accomplished via fluoroscopy, echo, or other visualization
and/or assessment techniques. If the user determines that the
results are not satisfactory, the procedure can be aborted by
removing the fastener catheter 52 (including the fastener 56) from
the patient's body and also removing the suture lines 46, 50, which
in the embodiment depicted can be achieved by pulling on one of the
trailing portions 64, 66 while letting go of the opposing trailing
portion, thereby removing the continuous suture loop formed by the
suture lines 46, 50.
[0077] In FIG. 2C, the fastener 56 is expanded and deployed, so
that the fastener 56 is released from the fastener catheter 52 and
securely holds the suture lines 46, 50 in place. The fastener 56 is
also expanded, with the expandable portion 62 blocking the PFO 14.
Note that the expansion and deployment of the fastener can be
performed as a single step, or as separate steps, depending on the
particular fastener and other parameters. If the expansion and
deployment are performed separately, the expansion may be performed
first, or the deployment may be performed first, again depending on
the particular fastener and other parameters. With the fastener 56
deployed, the catheter distal end 54 can be retracted over the
suture lines 46, 50 from the patient.
[0078] In FIG. 2D, the fastener catheter has been removed from the
PFO 14, and the trailing suture portions have been cut from the
suture lines 46, 50 (i.e., the suture lines 46, 40 have been cut
short adjacent the fastener 56). Depending on the particular
application and catheters involved, the excess suture portions can
be cut by the fastener catheter itself if the fastener catheter is
configured to cut suture. The excess suture portions could
alternatively be cut by a separate catheter configured to cut
suture. Examples of catheters having integrated suture cutting
mechanisms are disclosed in pending U.S. patent application Ser.
Nos. 11/174,143 and 11/174,357, the contents of each of which are
incorporated herein in their entirety by reference. The expanded
portion 62 of the expanded fastener 56 serves to occlude the PFO 14
and/or (depending on the particular fastener) serves as a structure
over which tissue can form to occlude the PFO 14.
[0079] In the embodiment depicted in FIGS. 1A-1D and 2A-2D, the
treatment catheter and fastener catheters were advanced and
positioned using a guide wire and/or the suture lines, but without
a guide catheter. Depending on the particular application, however,
including such factors as the flexibility or steerability of the
treatment and/or fastener catheters, a guide catheter may be used
with or without a guide wire, although most typically in
combination with the guide wire. The guide catheter can be advanced
over the guidewire to a position adjacent or within the PFO. The
treatment and fastener catheters can then be advanced and withdrawn
through the guide catheter.
[0080] Various fastener designs and configurations are within the
scope of the invention. Examples of some fasteners are discussed
below.
[0081] FIGS. 3A-3F depict an expandable fastener 70. In the side
views of FIGS. 3C and 3F, the fastener 70 is depicted positioned
over first and second suture lines 46, 50 and advanced adjacent
first and second tissue portions 38, 40 according to an embodiment
of the invention. The expandable fastener 70 is depicted in FIGS.
3A-3C in its unexpanded configuration, and in FIGS. 3D-3F in the
expanded condition. The expandable fastener 70 includes a locking
clip portion 72 and an expandable plug portion 74. In the
particular embodiment depicted, the locking clip portion 72 has a
distal opening 76, a proximal opening 78, and a central suture
lumen 80 running between the two openings 76, 78. The locking clip
portion 72 includes a lock in the form of a plurality of
inwardly-directed teeth 82 that act to close off the clip proximal
opening 78 when released. Note that in the unexpanded delivery
configuration of FIGS. 3A-3C the teeth 82 are positioned in an
"open" configuration, so that the proximal opening 78 and central
suture lumen 80 are largely unobstructed, and the suture lines 46,
50 can pass freely therethrough. In the deployed configuration of
FIGS. 3D-F, however, the teeth 82 are in their "closed" position,
where they are directed inward and obstruct the proximal opening
78, thereby preventing movement of the suture lines 46, 50 through
the fastener 70. The locking clip portion 72 can be formed from a
memory material such as Nitinol, and the teeth 82 may be biased
toward the "closed" position. The locking clip portion 72 is
preferably dimensioned to accommodate one or more suture lines
therethrough, such as the two suture lines 46, 50 depicted. The
dimensions of the locking clip portion 72 depend on the particular
application, but a relatively small outer diameter is generally
desirable for percutaneous applications. In one example of a
locking clip, the locking clip has an outer diameter of about 0.080
inches, a suture lumen inner diameter of about 0.050 inches, and a
length of about 0.060 inches. Note that other dimensions are also
within the scope of the invention, with the selection of specific
dimensions being dependant on a particular application.
[0082] The fastener 70 also includes an expandable plug portion 74,
which in the particular embodiment of FIGS. 3A-3F is a generally
flat disk of a flexible material that can be placed in an
unexpanded configuration where it is tightly positioned to give the
fastener 70 a relatively small diameter 84 as depicted in FIGS.
3A-3C, but can expand to a much larger diameter 84 as depicted in
FIGS. 3D-3F. As the fastener 70 expands in diameter, the length of
the expandable plug portion 74 shortens, thereby causing a
corresponding shortening in the length 86 of the fastener 70. The
expandable plug portion 74 may be formed from various materials,
including biocompatible materials, bioresorbable materials, and/or
tissue-growth inducing materials. For example, the expandable plug
portion could be formed from a biocompatible polymer that can flex
but will re-expand after being compressed or otherwise deformed.
The expandable plug portion 74 and/or locking clip portion 72 may
be formed and/or coated with materials that promote tissue
ingrowth, such as tissue-irritating materials that can provoke a
tissue growing response from the surrounding tissue. The expandable
plug portion 74 may be biased toward its expanded shape, so that it
must be physically held in the desired delivery shape (with smaller
diameter) but will expand to the desired expanded shape (and larger
diameter) when released. The expanded and delivery dimensions of
the fastener and expandable plug portion depend on the particular
application. It may generally be desirable to have a minimal
unexpanded diameter for the expandable plug portion in order to
facilitate percutaneous delivery of the fastener. The expandable
plug portion may have an unexpanded (delivery) diameter that is
about the same as that of the locking clip portion. For example,
the expandable plug portion may have an unexpanded diameter of
about 0.080 inches. The expanded diameter of the expandable plug
portion (and hence of the fastener) can vary depending on the
particular application. For example, for relatively small PFO's a
relatively small expanded diameter may be sufficient, while larger
PFO's may require larger expanded diameters. Expanded diameters
could range from 5 to 25 mm, and an expanded diameter of about 10
mm may be particularly useful in some applications.
[0083] The fastener 70 can be made of a single material or of a
combination of materials. For example, the locking clip portion 72
could be formed from shape memory metal such as Nitinol, and
combined with an expandable plug portion 74 formed from Nitinol,
stainless steel, polymeric materials, other biocompatible
materials, tissue-growth-inducing materials (e.g., Dacron), and/or
various combinations thereof.
[0084] FIGS. 4A-4D depict a fastener 70 such as that depicted in
FIGS. 3A-3F being deployed from a fastener catheter 52. In FIG. 4A,
the fastener 70 is secured in a fastener-holding sheath 90 at the
distal end 54 of the fastener catheter 52. A fastener catheter
inner member 92 passes into the fastener proximal opening 78. The
teeth 82 engage against the fastener catheter inner member 92, so
that the inner member 92 serves to hold the teeth 82 in their
"open" position while the inwardly-engaging teeth 82 secure the
fastener 70 to the inner member 92. The sheath 90 physically holds
the fastener expandable plug portion 74 in its delivery shape and
diameter, and also may protect the fastener and the patient's
tissues during delivery. The assembly is advanced over suture lines
46, 50 to tissue portions 38, 40, with the suture lines 46, 50
tightened.
[0085] In FIG. 4B, the sheath 90 is partially retracted from around
the expandable plug portion 74, so that the expandable plug portion
74 begins to expand outwardly. As the sheath is retracted, the
entire assembly may be advanced distally to maintain the sutures
46, 50 in the tightened condition and to maintain the fastener 70
adjacent the tissue portions 38, 40. In FIG. 4C, the sheath 90 is
fully retracted from the fastener 70, and the expandable plug
portion 74 is fully expanded. The fastener catheter inner member 92
is beginning to be slidingly retracted within the fastener catheter
main body member 94, so that the leading edge 96 of the main body
member 94 is engaging against the fastener clip portion 74 to push
the fastener 70 off of the inner member 92. At this point in the
procedure, the user can securely hold the fully expanded fastener
70 against the tissue portions 38, 40 and assess the quality of the
PFO closure using methods such as fluoroscopy, echo, etc. If the
user is not satisfied with the closure achieved with the fastener
70, the user can remove the fastener 70 entirely from the patient's
body and then advance another fastener (possibly having a different
size or other characteristics) to the site and/or abort the repair
and instead use another PFO repair procedure. To remove the
expanded fastener 70, the user advances the sheath 90 back over the
fastener 70 to re-compress the fastener 70 to its unexpanded
configuration, then withdraws the delivery catheter 52 and fastener
70 entirely from the patient. The user can then select another
fastener, which may have a different diameter or other
characteristics, and deliver the other fastener along the suture
lines to the treatment site. The user can then assess the PFO
closure achieved with the second fastener, and either deploy the
second fastener or remove the second fastener in favor of a third,
etc.
[0086] If the user is satisfied with the placement and expansion of
the fastener 70, the user can release the fastener 70 from the
delivery catheter 52 to lock the fastener 70 in position. In FIG.
4D, the fastener 70 has been pushed entirely off of the inner
member 92, and the teeth 82 of the locking clip 72 now engage
against the suture lines 46, 50 to hold the fastener securely
against the tissue portions 38, 40.
[0087] FIGS. 5A-5E depict a further embodiment of a fastener 100
with a locking clip portion 102 and an expandable portion 104. The
expandable portion 104 is formed from a plurality of struts 106,
which could be formed from various materials, such as Nitinol wire
that may be rounded to reduce stresses in strut bends. A flexible
membrane 108 could be added to extend between the struts 106, with
the struts 106 serving as scaffolding for the flexible membrane
108. The flexible membrane 108 could be formed of various
materials, including biocompatible materials such as Dacron and/or
PTFE. The flexible membrane 108 could be formed in various ways.
For example, the flexible membrane 108 could be formed from two
pieces of flexible material die cut in a generally circular shape
(with a cutout at the center to accommodate the locking clip
portion) to a desired diameter, with the first piece applied to one
side of the struts and the second piece applied to the opposite
side of the struts. The material(s) forming the flexible membrane
108 could be attached to the fastener 100 using various methods,
including adhesives, sutures, etc. The flexible membrane 108,
and/or the struts 106 and/or the locking clip portion 102, could
include materials having tissue-growth-inducing properties to
encourage the ingrowth of tissue over the expandable portion 174
and/or the locking clip portion 172.
[0088] In the delivery configuration depicted in FIGS. 5A-5B, the
diameter 110 of the fastener 100 is relatively small but the length
112 is relatively large, with the struts 106 generally aligned
longitudinally with the fastener clip portion 102 and suture lines
46, 50. In the side view of FIG. 5B, the fastener 100 is depicted
lying within a constraining outer sheath 114 of a fastener delivery
catheter 116.
[0089] In the deployed configuration depicted in FIGS. 5C-5E, the
diameter 110 of the fastener 100 is much larger, with the struts
106 extending radially outward from the fastener clip portion 102
and with the flexible membrane 108 filling the gaps between the
struts 106. The fastener 100 when expanded thus assumes a generally
disk-like shape having a relatively small length 112. Note that the
fastener depicted in FIGS. 5A-5E could be made using only the
struts for the expandable portion, i.e., without the flexible
membrane. FIGS. 5C and 5E depict the suture lines 46, 50, held
between the teeth 118 of the locking clip portion 102.
[0090] FIGS. 6A-6E depict a further embodiment of an expandable
fastener 120, with FIGS. 6A-6C depicting the unexpanded
configuration (with FIGS. 6B and 6C depicting the fastener 120 on a
fastener delivery catheter 121) and FIGS. 6D-6E depicting the
expanded condition. The expandable fastener 120 has a length 122
and an outer diameter 124. The particular expandable fastener 120
includes a distal section 126, a proximal section 128, and a middle
section 130 which, in the embodiment depicted, is an expandable
section. The fastener 120 includes a suture lumen 132 passing
through each of the three sections 126, 128, 130, which in the
embodiment depicted in FIGS. 6B and 6C is also configured to
receive an inner member 136 of the delivery catheter 121. The
expandable middle section 130 may be formed from a generally
flexible biocompatible material, such as polymers and/or flexible
bioabsorbable materials, which will deform when subjected to
longitudinal compression. In the particular embodiment depicted,
the expandable middle section 130 is formed from a tubular section
of a relatively thin and flexible membrane. The middle section 130
can be of various lengths and/or stiffness for different PFO sizes
and shapes.
[0091] In the unexpanded delivery configuration depicted in FIGS.
6A-6B, the suture lumen 132 is generally unobstructed throughout
the length 122 of the expandable fastener 120. As seen in FIG. 6B,
the fastener 128 is mounted on an inner member 136 of the fastener
delivery catheter 121, with multiple teeth 134 engaging against the
catheter inner member 136 to hold the fastener 120 thereon. Note
that the fastener 120 may not be self-expanding, so that an outer
sheath on the fastener delivery catheter 121 may not be needed to
constrain the fastener 120 during delivery.
[0092] To deploy the fastener 120, the catheter inner member 136 is
retracted into the catheter main body 138, so that the leading edge
139 of the catheter main body 138 engages against the fastener
proximal section 128 to push the fastener 120 off of the catheter
inner member 136. Once the catheter inner member 136 is removed
from all of the fastener 120 except for the fastener proximal
section 128, as depicted in FIG. 6C, the user can expand the
fastener 120 while still keeping the fastener 120 secured to the
catheter 121, which includes maintaining the locking teeth 134 in
the "open" position so that the suture lines 46, 50 can pass freely
therethrough.
[0093] The expansion of the expandable middle section 130 can be
achieved by pressing longitudinally (e.g., via a catheter), in a
distal direction, against the fastener proximal section 128.
Because the distal section 126 cannot substantially advance
distally due to the resistance from the tissue portions 38, 40 and
suture lines 46, 50, the expandable middle section 130 will be
compressed between the distal section 126 and proximal section 128.
As the expandable middle section 130 expands, the middle section
length 131 is reduced (which also reduces the overall length of the
entire fastener 122) while the outer diameter 124 is increased.
When the expandable fastener 120 is expanded, as depicted in FIGS.
6D-6E, the expandable middle section 130 deforms to expand radially
and shorten longitudinally.
[0094] Once the expandable middle section 130 reaches its fully
expanded diameter, the proximal section 128 can be locked in place
on the suture lines 46, 50, which can be accomplished in the
embodiment depicted by freeing the teeth 134 (e.g., by removing the
catheter inner member from within the teeth) to allow the teeth to
at least partially obstruct the suture lumen 132 as it passes
through the proximal section 128. The teeth 134 thus serve as a
lock to hold the suture lines 46, 50 tightly between the tissue 38,
40 and fastener 120 while also holding the fastener 120 in its
expanded condition. Note that other locks are also within the scope
of the invention, including locks that prevent movement of the
suture lines 46, 50 in just one direction (i.e., proximally through
the suture lumen 132, or distally through the suture lumen 132) as
well as locks that prevent movement of the suture lines 46, 50 in
both the proximal and distal directions.
[0095] In the embodiments of FIGS. 6A-6E, the suture lock in the
form of the inwardly-projecting teeth 134 was positioned proximally
of the expandable portion, namely in the fastener proximal section
128. In FIG. 7A, however, the lock in the form of teeth 134 is
instead positioned in the distal section 126 of the fastener 120,
with no locking mechanism being present in the proximal section 128
of the fastener 120. Such a configuration can be used with an
expandable fastener wherein the expandable portion does not need a
proximal locking portion to resist proximal deformation of the
expandable portion after deployment and expansion. For example,
where the expandable portion is permanently (i.e., non-elastically)
deformed during expansion, or is locked into the expanded position
by a locking mechanism other than a proximal-section lock, there
may be no need for the proximally-positioned locking mechanism.
Such an embodiment can allow a user to lock the unexpanded fastener
to the suture line, and then expand the fastener as a separate
step.
[0096] FIG. 7B depicts a further embodiment of the fastener 120,
but with locking teeth 134a, 134b in both the distal and proximal
sections 126, 128, respectively. Such an embodiment can allow a
user to lock the unexpanded fastener to the suture line using the
distal lock, and then expand the fastener as a separate step. The
proximal lock can then be secured to reinforce the lock on the
suture lines and/or to maintain the fastener in the expanded
configuration.
[0097] In the embodiments of FIGS. 6D-6E through 7B, the expandable
section assumed a generally spherical shape upon expansion.
However, other shapes are also within the scope of the invention,
depending on the particular application. For example, FIGS. 8A-8D
depict a fastener 140 with an expandable section 142 that is
generally cylindrical in both its unexpanded state (FIGS. 8A-8B)
and also in its expanded state (FIGS. 8C-8D). In the particular
embodiment depicted, the fastener length 144 remains relatively
constant during expansion, while the fastener outside diameter 146
increases. Such an expanded cylindrical shape may be suitable for
advancement and expansion within a tunnel-like opening, and may be
particularly suited for closure of PFO's and other openings having
generally tunnel-like shapes.
[0098] FIGS. 9A-9G depict a fastener 150 having an expandable
section 152 with two wing-like expansion sections 154a, 154b on
either side of the expandable section 152. A suture lumen 155 runs
along the length of the fastener. In the unexpanded state (FIGS.
9A-9C), the fastener 150 is generally cylindrical, but has slight
bulges along the sides of the expandable section 152 caused by the
unexpanded wing-like sections 154a, 154b. When expanded (FIGS.
9D-9G), the length 157 and height 158 of the fastener 150 remain
largely unchanged, while the width 156 increases substantially. The
fastener 150 thus assumes a generally flattened shape, with a width
156 that is substantially larger than its height 158.
[0099] In addition to the spherical, cylindrical, and generally
flat fastener shapes discussed above, other expanded fastener
shapes are also within the scope of the invention, depending on the
particular application.,
[0100] FIGS. 10A-10D depict a further embodiment of a fastener 160,
wherein the expandable portion 162 is an expandable cage formed
from deformable struts 164. The deformable struts 164 can be formed
from various materials, including metals, plastics, and other
biocompatible materials. The deformable struts 164 could be formed
from elastically deformable materials, plastically deformable
materials, and/or memory materials such as Nitinol. The fastener
160 has a length 166 and outside diameter 168 which vary during
expansion.
[0101] In FIGS. 10A-10B, the fastener 160 is in its unexpanded
configuration, with the deformable struts 164 generally straight
and aligned in parallel configuration about the radius of the
expandable portion 162. The suture lumen 170 is unobstructed so
that the suture lines 46, 50 can pass easily therethrough. In FIGS.
10C-10D, the fastener 160 is expanded into a generally spherical
cage-like shape, with the deformable struts 164 each deforming
generally equally along it length to form a generally semi-circular
arc shape. The fastener length 166 has shortened, while the
fastener diameter 168 has increased. Depending on the particular
application, this spherical shape can be the final expanded shape
of the fastener 160 during deployment. The fastener 160 can be
secured to the suture lines 46, 50 via one or more suture locks
(not shown), which could be positioned in the distal portion 169,
proximal portion 171, or elsewhere in or on the fastener 160. The
suture locks could comprise an inward flange, teeth, and/or other
mechanism to block the suture lumen 170 or otherwise prevent the
suture lines 46, 50 from passing through the fastener 160.
[0102] FIGS. 11A and 11B depict an additional expanded shape for a
fastener clip 160 such as that depicted in the unexpanded
configuration in FIGS. 10A-10B. The fastener clip 160 has been
shortened further, so that the fastener length 166 is much less
than the fastener diameter 168. The expandable portion 162 now
forms a disk-like shape, generally flat when viewed from the side
as in FIG. 11B and generally circular when viewed from the end as
in FIG. 11A.
[0103] By using different materials in different portions of the
expandable portion, a fastener can have other shapes upon
expansion. FIG. 12 depicts a mushroom-like expanded shape for a
fastener clip 160. Note that the fastener clip 160 has an
unexpanded configuration similar to that depicted in FIGS. 11A-11C.
The mushroom-like expanded shape could be achieved by forming the
fastener 160 from memory materials such as Nitinol, and setting the
mushroom-like shape as the preferred shape. Another approach for
achieving the mushroom-like shape involves forming different
portions of the expandable portion with different expansion
characteristics. For example, different portions of the expandable
struts could be formed from materials with different
characteristics. The fastener 160 could be configured with the
distal portions 172 of the struts 164 formed from material(s) that
resist deformation less than the material(s) used to form the
proximal portions 174 of the struts 164. As the fastener 160
expands radially and shortens lengthwise, the distal portions 172
will bend more than the proximal portions 174, resulting in a
generally mushroom-like or conical shape. Note that the
mushroom-like shape could be reversed to face the other direction
by making the proximal portions more resistant to bending, etc.
[0104] Another method for providing different expanded shapes
includes providing some strut portions (e.g., proximal portions)
with greater thickness and/or width, which may inherently give
those portions greater resistance to deformation. By making other
strut portions (e.g., distal portions) with less thickness and/or
width, the generally umbrella-like or conical shape discussed
above, or other desired shapes, can be achieved.
[0105] Another embodiment of an expandable fastener 180 is depicted
in FIGS. 13A-13D, where the fastener 180 includes a locking clip
182 and expandable portion 184. The expandable portion 184 is a
soft spiral spring, which could be formed from metal, polymers. In
the unexpanded collapsed (compressed) state, such as where the
fastener 180 is constrained by a catheter sheath 185 as depicted in
FIGS. 13A-13B, the soft spiral spring of the expandable portion 184
assumes a coiled spring configuration, with the fastener 180 having
a relatively large length 186 and relatively small diameter 188.
When the fastener 180 is deployed, such as where the fastener 180
is pushed out of the surrounding sheath 185, the expandable portion
184 assumes an expanded generally circular geometry, as seen in
FIGS. 143 and 143. The increased diameter 188 of the expandable
portion 184 increases the sealing area of the fastener 180.
[0106] FIGS. 14A-14D depict a further embodiment of a fastener 190
with a locking clip 192 surrounded by an expandable coil 194 of
bioresorbable material. In the delivery configuration (FIGS.
14A-14B), the diameter 196 of the expandable coil 194 is held to a
relatively small size (which may be accomplished by a fastener
catheter outer sheath (not shown) positioned around the fastener),
but when expanded (FIGS. 14C-14D) the diameter 196 is substantially
larger and serves to block the PFO opening and/or form a bridge
over which tissue can grow. The bioresorbable material may have
tissue-growth-inducing properties, and the surrounding tissue may
grow over and absorb the bioresorbable material, thereby
permanently closing the opening. Note that the locking clip 192 may
also be bioresorbable, as may be the suture lines to which the
fastener 190 is fastened, so that most or all of the repair
assembly will be absorbed into the patient's body over time.
[0107] FIGS. 15A-15B depict a fastener 200 in delivery
configuration having a locking clip portion 202 and a reservoir 204
of adhesive and/or foam-like material 206. Upon deployment (FIGS.
15C-15D), the reservoir 204 can rupture or otherwise open in order
to release the adhesive and/or foam-like material 206, which
expands around the locking clip portion 202 to block the PFO or
other opening, and/or to adhere the surrounding tissue and/or
fastener and/or suture together to close the opening. In an
embodiment where the reservoir 204 ruptures, it may be desirable
for the reservoir 204 to cleanly and predictably rupture so that
the material forming the lining 208 of the reservoir 204 remains
attached to the fastener 200. In another embodiment of the
invention, the adhesive and/or foam-like material is discharged
around the fastener from a reservoir or lumen on or in the fastener
delivery catheter and/or another catheter. The fastener 200 may
include a roughened outer surface and/or extending portions that
form recesses and other surfaces to which the adhesive and/or
foam-like material can expand around and/or adhere to.
[0108] FIGS. 16A-16B depict a fastener 210 in delivery
configuration having a locking clip portion 212 and an expandable
portion 214 formed of an expandable sponge-like material 216 that
expands when brought into contact with various materials, such as
blood and/or other body fluids. The expandable sponge-like material
216 may be bioresorbable and/or tissue-growth-inducing. When the
expandable portion 214 expands (FIGS. 16C-16D), which may occur
gradually as the sponge-like material 216 absorbs fluids, the
expandable portion 214 serves to block the PFO opening and/or form
a bridge over which tissue can grow to block the opening.
[0109] In another embodiment of the invention depicted in FIGS.
17A-17D, a fastener 220 includes a locking clip portion 222 and one
or more plug portions 224 of plug and/or tissue-growth-inducing
material. In the particular embodiment of FIGS. 17A-17D, a trailing
plug portion 224 is a skirt of cloth 226. The cloth 226 may be a
tissue-irritating material that will induce tissue ingrowth when
brought into contact with tissue. In such an embodiment, the
locking clip 222 is advanced into position and locked into place
along the suture lines 46, 50 and adjacent the tissue portions 38,
40, as depicted in FIGS. 17A-17B. The trailing plug portion 224,
which in the embodiment depicted in FIG. 17A was restrained by an
outer sheath 227 of a delivery catheter, is then released to expand
and/or spread out from the locking clip portion, as depicted in
FIGS. 17C-17D, at which point the cloth 226 by its physical bulk
helps to plug the PFO. The cloth 226 when released also comes into
contact with the tissue. The tissue-irritating quality of the cloth
226 induces the tissue to grow over the cloth 226, which in time
will further reinforce the closure of the PFO. Note that, depending
on the particular opening and other deployment characteristics, the
trailing cloth skirt 226 may not form the generally circular shape
depicted in FIG. 18B, and may even be held tightly between tissue
portions so that the trailing plug portion 224 is restrained into a
very small size.
[0110] FIGS. 18A-18B depict a fastener 220 similar to that of FIGS.
17A-17D, except the trailing plug portion 224 comprises suture
strands 228. The suture strands 228 may have tissue-irritating and
growth-inducing properties. When the locking clip portion is locked
into place on the suture lines adjacent tissue portions at or
within a PFO or other opening, the trailing suture strands 228 may
help to block the PFO by their bulk and/or by inducing the
surrounding tissue to grow over the trailing suture strands. Note
that FIGS. 18A and 18B depict the fastener 220 in the expanded
condition. In the unexpanded condition, the suture strands 228 will
be compressed to a much smaller diameter, similar to the manner in
which the cloth skirt 226 was compressed in the embodiment of FIGS.
17A and 17B. When released from a restraint such as a catheter
sheath, the trailing suture strands 228 can conform to the opening.
Depending on the particular opening and other deployment
characteristics, the trailing suture strands 228 may not form the
generally circular shape depicted in FIG. 18B, and may even be held
tightly between tissue portions so that the trailing plug portion
224 is restrained into a very small size.
[0111] The embodiments depicted in FIGS. 17A-17D and 18A-18B use
trailing plug portions of materials, such as cloth and/or suture.
However, the plug materials do not have to be positioned to trail
behind the locking clip. For example, the plug materials (which may
be tissue-growth-inducing materials) could be placed in front of,
on the sides of, and/or all around the locking clip or other
structures of the fastener. In addition to or in lieu of the cloth
and suture depicted in FIGS. 17A-17D and 18A-18D, other materials
could be used as plug materials. For example, microscopic PTFE
fibers, which could be in the form of a pledget, may be attached to
the fastener.
[0112] FIGS. 19A-19B depict a further embodiment of the invention,
wherein first and second tissue-irritating suture lines 230, 232
themselves have enhanced tissue irritating qualities to induce
tissue growth. For example, cat-gut suture, and/or suture having a
generally rough or irritating surface (as opposed to the relatively
smooth surface of most prolene sutures), and/or a suture containing
or coated with chemicals having tissue-irritating and/or
tissue-growth-inducing qualities, could be used in performing the
repair. In FIG. 19A, the suture lines 230, 232 have recently been
deployed through first and second tissue portions 234, 236,
respectively, with a fastener 238 holding the suture lines 230, 232
firmly adjacent the tissue portions 234, 236. Note that in the
embodiment depicted, the tissue portions 234, 236 are anterior and
posterior leaflets, respectively, of a mitral valve. The
surrounding tissue has not yet grown onto or into the suture lines
230, 232. In FIG. 19B, the surrounding tissue has grown over the
suture lines 230, 232, forming a tissue bridge 240 between the
first and second tissue portions 234, 236. Such tissue-irritating
suture lines could be used in various procedures where an opening
is desired to be closed. For example, in an edge-to-edge leaflet
procedure conducted on a bicuspid mitral valve, a tissue-irritating
suture line could be used to secure the first leaflet to the second
leaflet. The tissue-irritant suture line would thus induce tissue
formation over the resulting stitch, which would further reinforce
the connection between the first leaflet and the second leaflet.
The tissue-irritant suture line could be bioresorbable. The
tissue-irritant suture line could also be used in combination with
a tissue-irritant and/or bioresorbable fastener. Where a suture
and/or fastener is bioresorbable, it may be preferred that the
bioresorbability be configured so that the suture and/or fastener
is not bioresorbed prior to formation of the tissue bridge of other
tissue growth over the suture and/or fastener.
[0113] In a further embodiment of the invention, multiple fasteners
can be employed, including multiple expandable and/or multiple
unexpandable fasteners and various combinations thereof. For
example, in FIG. 20A, a first fastener 250, which in the particular
embodiment depicted is an expandable fastener, is deployed to
secure the suture lines 46, 50 and tissue portions 38, 40 of a PFO
14. (Note, however, that an unexpandable fastener could instead be
used as the first fastener.) The excess suture portion 64, 66 have
not yet been removed, so that a user has the option of deploying
additional fasteners along the suture lines 46, 50. Note that the
first fastener 250 is deployed within the PFO itself. With the
first fastener 250 deployed, the user can assess the efficacy of
the repair using various assessment techniques, including
visualization techniques such as fluoroscopy and/or echo. If the
user can not confirm the completeness of the repair, the user can
advance one or more additional fasteners along the suture lines 46,
50 to the repair site. In FIG. 20B, the user has delivered and
deployed a second fastener 252, which in the particular embodiment
depicted is an expandable fastener. Note that the second fastener
is a generally disk-shaped fastener and is positioned adjacent the
proximal opening of the PFO instead of within the PFO. With the
second fastener 252 in position and expanded, the user can again
assess the efficacy of the repair, and if desired can add
additional fasteners. Once the user is satisfied with the repair,
the user will cut and remove the excess suture portions 64, 66,
leaving the fasteners (e.g., 250, 252) in place to hold the tissue
38, 40 together.
[0114] In another embodiment of the invention, one or more locking
fasteners are used with intervening expandable portions and/or
other plug materials to close a PFO. In FIG. 21A, the user has
delivered and deployed a first fastener 260 on sutures lines 46, 50
in a PFO 14. In the particular embodiment depicted, the fastener
260 is an unexpandable fastener; however, an expandable fastener
could instead be used as a first-deployed fastener. With the first
fastener 260 deployed, the user can assess the efficacy of the
repair using various assessment techniques, including visualization
techniques such as fluoroscopy and/or echo. If the user desires
(e.g., if the user can not confirm the completeness of the repair),
the user can advance one or more plugs along the suture lines 46,
50 to the repair site. (Note that, if the user desires, one or more
plugs may be advanced along the suture lines to the PFO prior to or
simultaneously with placement of the first fastener at the PFO.) In
FIG. 21B, a plug 262, which in the particular embodiment depicted
is a piece of tissue-irritating cloth, has been advanced along the
suture lines 46, 50 until the plug 262 is adjacent the first
fastener 260 and the tissue portions 38, 40. The plug 262, depicted
in front view in FIG. 21C, has a central opening 264 through which
the suture lines 46, 50 can pass. The central opening 264 may
preferably be a bounded opening so that the suture lines 46, 50
cannot slip sideways through the plug 262 (i.e., can only pass
longitudinally through the plug 262 through the central opening
264), which will prevent the plug from sliding sideways off of the
suture lines 46, 50. The central opening 264 may also be sized and
configured so that the sutures 46, 50 can pass therethrough but a
fastener deployed proximally of the plug 262 will not slip through
the plug central opening 264.
[0115] A second fastener 266 (which in the particular embodiment
depicted is an unexpandable fastener) is advanced along the suture
lines 46, 50 until it is seated and locked into position against
the plug 262. The plug 262 is thus held firmly on the suture lines
46, 50 between the first and second fasteners 260, 266, as depicted
in FIG. 21D. Additional plugs and fasteners can be deployed until
the PFO is securely closed or the user is otherwise satisfied with
the repair. After all plugs and fasteners are deployed, the user
will cut and remove the excess suture portions 64, 66 of sutures
46, 50.
[0116] Note that one or more plugs can be deployed along the suture
lines prior to deployment of the first fastener, with the first
fastener positioned and secured to the suture lines proximally of
the plug or plugs. In one such embodiment, a first plug is advanced
to the treatment site and held against the tissue portions (which
may be accomplished with a plug and/or fastener delivery catheter)
while the user assesses the efficacy of the repair using methods
such as fluoroscopy, etc. If the user desires, the user can advance
additional plugs to the repair site until the user is satisfied
with the repair, then advance a fastener clip to hold the plug or
plugs firmly in place against the tissue portions to complete the
repair. In such an embodiment, the plug or plugs will be held
firmly on the suture lines, sandwiched between the tissue portions
and the first fastener. The deployment of multiple plugs with a
single fastener can be part of a single fastener deployment, or as
a combination of multiple plugs and multiple fasteners such as that
described above with respect to FIGS. 21A-D.
[0117] The invention includes various placements of the suture
lines, fasteners, and/or plugs with respect to the PFO or other
treatment site. In one embodiment depicted in FIG. 22A, the suture
lines 46, 50 are deployed in a distal area of the PFO 14, and a
fastener 70 is advanced and deployed within the PFO 14 itself. In
another embodiment depicted in FIG. 22B, a fastener 70 is deployed
and expanded adjacent the proximal opening 270 of the PFO 14, so
that the fastener 70 presents a generally flat surface that presses
against (and may conform to) the tissue surrounding the proximal
opening 270 of the PFO. The fastener 70 thus serves as a lid-like
closure on the PFO 14. Note that the selection of a particular
fastener used for a particular procedure may depend on the desired
deployment characteristics. A generally flat disk-like fastener may
be desirable to form a lid-like closure such as that depicted in
FIG. 22B, while an expanding plug of tissue-growth-inducing
material may be desirable for a plug-like closure within the PFO
such as that depicted in FIG. 22A.
[0118] Note that the fasteners of the invention can have various
configurations and/or be formed of various materials. For example,
a fastener locking clip, expandable portion, and/or plug portion
could be formed from various materials and combinations thereof,
including foam-like structures, cloth, coils, tissue-irritating
materials that will induce tissue ingrowth, bioresorbable
materials, etc. Various dimensions of the fastener could be altered
to suit a particular application. For example, the suture lumen
does not necessarily have to be shaped having a length greater than
the diameter, and instead of a long suture lumen the suture could
instead pass through any opening in the clip configured to
slidingly receive at least one line of suture. The suture of the
invention could also have various characteristics, including
bioresorbability and/or tissue-growth-inducing properties.
[0119] While the invention has been described with reference to
particular embodiments, it will be understood that various changes
and additional variations may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention or the inventive concept thereof. For example,
while the invention has been discussed in detail in the application
with repair of septal defects such as PFOs, it has applicability in
other areas where it is desired to repair tissue and/or close
openings. For example, the invention may be used to close body
lumens and/or openings, including a left atrial appendage, or in
so-called edge-to-edge mitral valve repairs, etc. In addition, many
modifications may be made to adapt a particular situation or device
to the teachings of the invention without departing from the
essential scope thereof. Therefore, it is intended that the
invention not be limited to the particular embodiments disclosed
herein, but that the invention will include all embodiments falling
within the scope of the appended claims.
* * * * *