U.S. patent application number 10/655867 was filed with the patent office on 2004-03-11 for filter apparatus for ostium of left atrial appendage.
Invention is credited to Borillo, Thomas E., Hauser, Robert G., Holmes, David, Schwartz, Robert, Sutton, Gregg S., VanTassel, Robert A., Welch, Jeffrey.
Application Number | 20040049210 10/655867 |
Document ID | / |
Family ID | 27575154 |
Filed Date | 2004-03-11 |
United States Patent
Application |
20040049210 |
Kind Code |
A1 |
VanTassel, Robert A. ; et
al. |
March 11, 2004 |
Filter apparatus for ostium of left atrial appendage
Abstract
A membrane applied to the ostium of an atrial appendage is
disclosed. The membrane prevents blood clots in the atrial
appendage from escaping therefrom and entering the blood stream
which can result in a blocked blood vessel, leading to strokes and
heart attacks. The membrane may be permeable or impermeable with
respect to blood flow. The membrane is configured to extend over
the ostium of the left atrial appendage. The membrane has an outer
periphery with a dimension larger than a corresponding dimension of
the ostium. Securement means is provided to secure the outer
periphery of the membrane in direct engagement with the atrial wall
surrounding the ostium. The securement means may located between
the membrane and the atrial wall, or the securement means may
extend distally from the membrane through the ostium.
Inventors: |
VanTassel, Robert A.;
(Excelsior, MN) ; Hauser, Robert G.; (Long Lake,
MN) ; Schwartz, Robert; (Rochester, MN) ;
Holmes, David; (Rochester, MN) ; Sutton, Gregg
S.; (Maple Grove, MN) ; Borillo, Thomas E.;
(Plymouth, MN) ; Welch, Jeffrey; (New Hope,
MN) |
Correspondence
Address: |
FISH & NEAVE
1251 AVENUE OF THE AMERICAS
50TH FLOOR
NEW YORK
NY
10020-1105
US
|
Family ID: |
27575154 |
Appl. No.: |
10/655867 |
Filed: |
September 5, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10655867 |
Sep 5, 2003 |
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09642291 |
Aug 18, 2000 |
|
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|
6652555 |
|
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|
09642291 |
Aug 18, 2000 |
|
|
|
09614091 |
Jul 11, 2000 |
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09614091 |
Jul 11, 2000 |
|
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09428008 |
Oct 27, 1999 |
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6551303 |
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Current U.S.
Class: |
606/151 |
Current CPC
Class: |
A61B 2017/081 20130101;
A61B 2017/0641 20130101; A61F 2/0103 20200501; A61B 17/0643
20130101; A61B 17/12131 20130101; A61B 17/12136 20130101; A61B
17/12122 20130101; A61B 17/12159 20130101; A61B 17/12022 20130101;
A61F 2002/018 20130101; A61B 17/122 20130101; A61B 2017/1205
20130101; A61B 2017/00628 20130101; A61B 17/0057 20130101; A61F
2230/0006 20130101; A61F 2230/0069 20130101; A61B 17/12172
20130101; A61F 2230/008 20130101; A61B 17/00234 20130101; A61B
2017/00243 20130101 |
Class at
Publication: |
606/151 |
International
Class: |
A61B 017/08 |
Claims
What is claimed is:
1. Apparatus for attachment over an ostium of a left atrial
appendage in a patient, comprising: a membrane configured to extend
over the ostium of the left atrial appendage, the membrane having
an outer periphery with a dimension larger than a corresponding
dimension of the ostium; and securement means to secure the outer
periphery of the membrane in direct engagement with the atrial wall
surrounding the ostium.
2. The apparatus defined in claim 1, wherein the securement means
is located between the outer periphery of the membrane and the
atrial wall surrounding the ostium.
3. The apparatus defined in claim 2, wherein the securement means
comprises an adhesive applied between the outer periphery of the
membrane and the atrial wall surrounding the membrane.
4. The apparatus defined in claim 3, wherein the adhesive is
cyanoacrylate.
5. The apparatus defined in claim 2, wherein the securement means
comprises a plurality of engagement members attached to the
membrane at a plurality of locations about the outer periphery of
the membrane.
6. The apparatus defined in claim 5, wherein the engagement members
are configured to penetrate the atrial wall surrounding the
ostium.
7. The apparatus defined in claim 6, wherein the engagement members
each comprise a barbed configuration to engage the atrial wall
surrounding the ostium to inhibit removal of the engagement member
from the atrial wall.
8. The apparatus defined in claim 5, wherein the engagement members
each comprise a shank portion extending distally from the outer
periphery of the membrane and at least partially into the
ostium.
9. The apparatus defined in claim 8, wherein the engagement members
mounted on opposite sides of the membrane define a spacing
substantially identical to an interior dimension of the ostium.
10. The apparatus defined in claim 8, wherein the engagement
members each comprise a barbed configuration to engage an interior
wall of the atrial appendage.
11. The apparatus defined in claim 1, wherein the securement means
comprises a structure configured to extend distally from the
membrane into the ostium and to engage a portion of the interior
the left atrial appendage.
12. The apparatus defined in claim 11, wherein the securement means
is configured for enlargement in response to expansion of an
expansion structure located in an interior portion of the
securement means.
13. The apparatus defined in claim 11, wherein the securement means
is resiliently biased in a enlarged configuration for engagement
with the interior wall of the left atrial appendage and may be
constrained in a reduced size configuration for installation in the
left atrial appendage.
14. The apparatus defined in claim 1, wherein the membrane has a
permeable structure which allows blood to flow through the membrane
but substantially inhibits thrombus from passing therethrough.
15. The apparatus defined in claim 1, wherein the membrane has an
impermeable structure which substantially inhibits thrombus and
blood from passing therethrough.
16. The apparatus defined in claim 1, wherein the securement means
comprises membrane supporting structure attached to the outer
periphery of the membrane and configured to extend radially outward
from the ostium to secure the outer periphery of the membrane in
direct engagement with the atrial wall surrounding the ostium.
Description
[0001] This application is a divisional of application Ser. No.
09/642,291, filed Aug. 18, 2000, which is a continuation-in-part of
application Ser. No. 09/614,091, filed Jul. 11, 2000, which is a
continuation-in-part of application Ser. No. 09/428,008, filed Oct.
27, 1999, (now U.S. Pat. No. 6,551,303) all of which are
incorporated by reference in their entirety herein. The application
Ser. No. 09/614,091, filed Jul. 11, 2000 also claims the benefit of
U.S. provisional application No. 60/196,454, filed Apr. 11, 2000,
U.S. provisional application No. 60/206,967, filed May 25, 2000,
U.S. provisional application No. 60/209,511, filed Jun. 5, 2000,
and U.S. provisional application No. 60/211,896, filed Jun. 16,
2000. The application Ser. No. 09/642,291, filed Aug. 18, 2000 also
claims the benefit of U.S. provisional application No. 60/196,454,
filed Apr. 11, 2000, U.S. provisional application No. 60/206,967,
filed May 25, 2000, U.S. provisional application No. 60/209,511,
filed Jun. 5, 2000, U.S. provisional application No. 60/211,896,
filed Jun. 16, 2000, and U.S. provisional application No.
60/217,125, filed Jul. 10, 2000, all of which are incorporated by
reference in their entirety herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a membrane structure applied to or
across the ostium of an atrial appendage to prevent a thrombus from
leaving the atrial appendage.
[0004] 2. Description of the Related Art
[0005] There are a number of heart diseases (e.g., coronary artery
disease, mitral valve disease) that have various adverse effects on
the heart. An adverse effect of certain cardiac diseases, such as
mitral valve disease, is atrial (or auricular) fibrillation. Atrial
fibrillation may result in pooling of blood in the left atrial
appendage. Blood pooling may also be spontaneous. When blood pools
in the atrial appendage, blood clots can form and accumulate
therein, build upon themselves, and propagate out from the atrial
appendage into the atrium. These blood clots can then enter the
systemic or pulmonary circulations and cause serious problems if
they migrate from the atrial appendage and become free in the blood
stream and embolize distally into the arterial system. Similar
problems also occur when a blood clot extending from an atrial
appendage into an atrium breaks off and enters the blood supply.
Since blood from the left atrium and ventricle supply the heart and
brain, blood clots from the atrial appendages can obstruct blood
flow therein causing heart attacks, strokes or other organ
ischemia. It is therefore necessary to find a means of preventing
blood clots from forming in the atrial appendages and to prevent
these blood clots, once formed, from leaving the atrial appendages
to the heart, lungs, brain or other circulations of the patient
which can cause heart attacks or strokes or other organ
ischemia.
[0006] U.S. Pat. No. 5,865,791 relates to the reduction of regions
of blood stasis and ultimately thrombus formation in such regions,
particularly in the atrial appendages of patients with atrial
fibrillation. More specifically, the '791 patent relates to
procedures and devices for affixing the atrial appendages in an
orientation that prevents subsequent formation of thrombus. In the
'791 patent, the appendage is removed from the atrium by pulling on
it and by putting a loop around it to form a sack of the atrial
appendage and then cutting it off from the rest of the heart.
[0007] U.S. Pat. No. 5,306,234 relates to a method for surgically
closing the passage between the atrium and the atrial appendage or
severing the atrial appendage.
[0008] Other methods of treatment include surgically removing the
atrial appendages to prevent blood stasis in the atrial
appendages.
SUMMARY OF THE INVENTION
[0009] The invention provides a membrane that substantially
prevents blood clots formed in the atrial appendages from exiting
therefrom. Such clots may cause heart attacks, strokes and other
embolic events if allowed to leave the atrial appendage and enter
the bloodstream. The membrane is permanently positioned across the
ostium of the atrial appendage by direct securement means to the
ostium or the atrial wall adjacent the ostium.
[0010] The membrane effectively isolates blood clots inside the
left atrial appendage from leaving and entering the atrium. It may
be larger than the ostium of the appendage, and extend over an area
larger than the ostium. The membrane may be percutaneously
delivered to the ostium of the atrial appendage by a catheter and
then may be expanded for positioning across or over the ostium.
[0011] According to one embodiment, the membrane is impermeable to
blood flow. This membrane inhibits thrombus in the left atrial
appendage from exiting and entering the bloodstream. The membrane
also prevents blood from flowing into or out of the left atrial
appendage.
[0012] According to another embodiment, the membrane itself is
permeable to permit blood flow across the membrane. By allowing the
such blood flow across the membrane, the permeable structure
minimizes any pressure gradient between the atrial appendage and
the atrium in a controlled manner. Moreover, the permeable membrane
acts as a filter in allowing blood to flow across, but
substantially inhibits the passage of thrombus therethrough.
[0013] The permeable filtering membrane may eventually become
infiltrated with cells. The permeable filtering membrane allows
such tissue growth which may begin along the outer periphery of the
structure. Such tissue growth minimizes uncontrolled leakage about
the periphery of the filtering membrane and may assist in
attachment of the filtering membrane across the ostium to tissue
surrounding the ostium. The filtering membrane may be coated or
covered with an anticoagulant or other compounds, such as, for
example, heparin, or it may be treated to prevent thrombus from
forming on the filtering membrane surface, to extend its patency or
until it is infiltrated with cells and/or develops an endothelial
covering.
[0014] There are many means for securing the membrane in position
across the ostium of the atrial appendage. Direct securement means
for the membrane may be provided by a biocompatible adhesive
applied between the membrane and the ostium or the atrial wall. In
this manner, the membrane can be adhered directly to the tissue. In
another embodiment, direct securement is made by the use of
staples, clips, sutures, wires, barbs, prongs or other methods of
fixation which pass through the tissue of the ostium or atrial
wall. In yet another embodiment, direct securement is achieved by
the use of structure connected to the membrane which extends
through the ostium and into the interior of the atrial appendage
and engages the interior of the atrial appendage, wherein the
interior wall of the atrial appendage may also include any portion
of the ostium extending within the atrial appendage. The direct
securement means may provide a self-centering feature for the
membrane about the appendage ostium.
OBJECTS OF THE INVENTION
[0015] It is an object of the invention to provide a membrane
between the atrium and atrial appendage to prevent blood clots from
flowing therebetween.
[0016] It is an object of the invention to provide a membrane which
is permanently implanted between the atrium and the atrial
appendage by direct securement to the ostium or the atrial wall
adjacent the ostium.
[0017] It is an object of the invention to provide a membrane
between the atrium and the atrial appendage which is impermeable to
blood flow or the passage of thrombus.
[0018] It is an object of the invention to provide a filtering
membrane between the atrium and atrial appendage to allow blood
flow across the filter, e.g., to reduce any hemodynamic pressure
differential therebetween.
[0019] It is an object of the invention to prevent blood clots from
forming in the atrial appendage.
[0020] It is an object of the invention to position across the
ostium of the atrial appendage a non-thrombogenic, biocompatible
surface that prevents blood clots from forming.
[0021] It is an object of the invention to provide a permeable
filtering membrane surface which may eventually become lined with
endothelial or endocardial cells.
[0022] It is an object of the invention to isolate the atrial
appendage from the atrium proper with respect to the passage of
thrombus with a filtering membrane, while allowing communication
through which blood may flow.
[0023] It is an object of the invention to minimally invasively
prevent blood clots from forming in the atrial appendages and
escaping therefrom.
[0024] It is an object of the invention to prevent thrombus by use
of heparin, other antithrombogenic substances, or other compounds
on or eluted from the membrane.
[0025] It is an object of the invention to ensure the membrane is
centered across or over the ostium of the atrial appendage.
[0026] It is an object of the invention to accurately place the
membrane across or over the ostium of the atrial appendage.
[0027] Other objects, advantages and novel features of the present
invention will become apparent from the following detailed
description of the invention when considered in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a partial cross sectional view of a heart showing
a catheter entering the left atrial appendage using a retrograde
procedure from the aorta in accordance with the invention.
[0029] FIG. 2 is a partial cross sectional view of a heart showing
a catheter entering the left atrial appendage using a transeptal
procedure from the femoral vein or superior vena cava in accordance
with the invention.
[0030] FIG. 3 is a partial cross sectional view of a heart showing
a catheter entering the right atrial appendage from the jugular
vein or optionally from the femoral vein in accordance with the
invention.
[0031] FIG. 4 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage.
[0032] FIG. 5 is a partial cross sectional view of a delivery
catheter having a disk, a spring and membrane therein in accordance
with the invention.
[0033] FIG. 6 is a schematic view of a disk, spring and membrane
after being expanded out of the delivery catheter of FIG. 5 in
accordance with the invention.
[0034] FIG. 7 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage having
a disk, a membrane and a spring therebetween in accordance with the
invention.
[0035] FIG. 8 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage shown
in a collapsed position in accordance with the invention.
[0036] FIG. 9 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage having
a disk, a spring, a membrane and vacuum in the catheter in
accordance with the invention.
[0037] FIG. 10 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
an umbrella folded for entering the atrial appendage in accordance
with the invention.
[0038] FIG. 11 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
the umbrella opened in the atrial appendage to secure the umbrella
into the wall of the atrial appendage in accordance with the
invention.
[0039] FIG. 12 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
the umbrella and membrane positioned across the ostium of the
atrial appendage in accordance with the invention.
[0040] FIG. 13 is a partial cross sectional view of a portion of a
heart showing an atrium and its associated atrial appendage showing
the atrial appendage reduced to a minimum volume by a disk and
spring squeezing the appendage against a membrane in accordance
with the invention.
[0041] FIG. 14 is a perspective view of another embodiment of a
filtering membrane and apparatus for installing the filtering
membrane in accordance with the invention.
[0042] FIG. 15 is a sectional view of the filtering membrane and
apparatus illustrated in FIG. 14, in accordance with the
invention.
[0043] FIG. 16 is an enlarged view of a portion of the apparatus of
FIG. 15 in accordance with the invention.
[0044] FIG. 17 is a partial cross-sectional view illustrating an
early stage in the installation of the apparatus of FIG. 14, in
accordance with the invention.
[0045] FIG. 18 is a partial cross-sectional view similar to FIG.
17, illustrating a later stage in the procedure in accordance with
the invention.
[0046] FIG. 19 illustrates another embodiment of the filtering
membrane and apparatus for installing the filtering membrane in
accordance with the invention.
[0047] FIG. 20 is an enlarged view of the filtering membrane and
apparatus illustrated in FIG. 19 in accordance with the
invention.
[0048] FIG. 21 is a planar development of the apparatus for
attaching the filtering membrane illustrated in FIGS. 19-20 in
accordance with the invention.
[0049] FIG. 22 is an enlarged perspective view of a portion of the
apparatus of FIG. 21, in accordance with the invention.
[0050] FIG. 23 is a planar development of the apparatus depicted in
FIG. 21 in an expanded configuration, in accordance with the
invention.
[0051] FIG. 24 is a perspective view of the filtering membrane and
apparatus for attaching the filtering membrane of FIG. 20,
illustrated in an expanded configuration in accordance with the
invention.
[0052] FIG. 25 is an elevational view of an embodiment of the
filtering membrane in accordance with the invention.
[0053] FIG. 26 is an elevational view of another embodiment of the
filtering membrane in accordance with the invention.
[0054] FIG. 27 is an elevational view of yet another embodiment of
the filtering membrane in accordance with the invention.
[0055] FIG. 28 is an elevational view of a further embodiment of
the filtering membrane in accordance with the invention.
[0056] FIG. 29 is a partial cross-sectional view illustrating an
early stage in the procedure of installing of the filtering
membrane of FIGS. 19-28 in accordance with the invention.
[0057] FIG. 30 is a partial cross-sectional view similar to FIG. 29
illustrating a later stage in the procedure in accordance with the
invention.
[0058] FIG. 31 is a partial cross-sectional view similar to FIG. 30
illustrating a still later stage in the procedure in accordance
with the invention.
[0059] FIG. 32 is a view similar to FIG. 31 illustrating an
alternative embodiment of the apparatus illustrated in FIGS.
19-23.
[0060] FIG. 33 is a partial cross-sectional view similar to FIG. 32
illustrating a later stage in the procedure in accordance with the
invention.
[0061] FIG. 34 is a partial cross-sectional view similar to FIG. 33
illustrating a still later stage in the procedure in accordance
with the invention.
[0062] FIG. 35(a) illustrates an alternative embodiment of the
apparatus illustrated in FIGS. 19-20 in accordance with the
invention.
[0063] FIG. 35(b) illustrates the apparatus illustrated in FIG.
35(a) in an expanded configuration in accordance with the
invention.
[0064] FIG. 36 is a view similar to FIG. 35(b) illustrating another
embodiment in accordance with the invention
[0065] FIG. 37 illustrates yet another embodiment of the filtering
membrane and apparatus for attaching the filtering membrane in
accordance with the invention.
[0066] FIG. 38 is an elevational view taken from direction 38 of
FIG. 37 in accordance with the invention.
[0067] FIG. 39 is elevational view taken from direction 39 of FIG.
37 in accordance with the invention.
[0068] FIG. 40 is a sectional view illustrating the apparatus of
FIGS. 37-39 along with additional apparatus in accordance with the
invention.
[0069] FIG. 41 is a partial cross-sectional view illustrating a
first installed configuration of the apparatus of FIGS. 37-39 in
accordance with the invention.
[0070] FIG. 42 is a partial cross-sectional view similar to FIG. 41
illustrating a second installed configuration of the apparatus of
FIGS. 37-39 in accordance with the invention.
[0071] FIG. 43 is a partial cross-sectional view illustrating
another embodiment of the apparatus in accordance with the
invention.
[0072] FIG. 44 illustrates a further embodiment of the apparatus in
accordance with the invention.
[0073] FIG. 45 is an end view of the apparatus of FIG. 44 in
accordance with the invention.
[0074] FIG. 46 illustrates a still further embodiment of the
apparatus in accordance with the invention.
[0075] FIG. 47 illustrates additional apparatus for use with the
apparatus of FIGS. 44-46 in accordance with the invention.
[0076] FIG. 48 is an enlarged sectional view of the apparatus of
FIG. 47 in accordance with the invention.
[0077] FIG. 49 is a partial cross-sectional view of the apparatus
of FIGS. 44-45 illustrating an early stage in the procedure in
accordance with the invention.
[0078] FIG. 50 is a partial cross-sectional view similar to FIG. 49
illustrating a later stage in the procedure in accordance with the
invention.
[0079] FIG. 51 illustrates yet another embodiment of the apparatus
in accordance with the invention.
[0080] FIG. 52 is an end view of the apparatus of FIG. 51 in
accordance with the invention.
[0081] FIG. 53 illustrates additional apparatus for use with the
apparatus of FIGS. 51-52 in accordance with the invention.
[0082] FIG. 54 is an enlarged sectional view of the apparatus of
FIGS. 51 and 53 in accordance with the invention.
[0083] FIG. 55 is a partial cross-sectional view of the apparatus
of FIG. 51 illustrating an early stage in the procedure in
accordance with the invention.
[0084] FIG. 56 is a partial cross-sectional view similar to FIG. 55
illustrating a later stage in the procedure in accordance with the
invention.
[0085] FIG. 57 illustrates another embodiment of the apparatus in
accordance with the invention.
[0086] FIG. 58 illustrates yet another embodiment of the apparatus
in accordance with the invention.
[0087] FIG. 59 is a partial cross-sectional view of the apparatus
of FIG. 57 illustrating an early stage in the procedure in
accordance with the invention.
[0088] FIG. 60 is a partial cross-sectional view similar to FIG. 59
illustrating a later stage in the procedure in accordance with the
invention.
[0089] FIG. 61 is a simplified elevational view of another
embodiment of the membrane in accordance with the invention.
[0090] FIG. 62 is a side view of the membrane taken from direction
62 of FIG. 61, in accordance with the invention.
[0091] FIG. 63 is view in partial section of the membrane of FIGS.
61-62 illustrating a typical use in accordance with the
invention.
[0092] FIG. 64 is view in partial section of the yet another
embodiment of the membrane, illustrating a typical use in
accordance with the invention.
[0093] FIG. 65 is a simplified elevational view of still another
embodiment of the membrane in accordance with the invention.
[0094] FIG. 66 is a side view of the membrane taken from direction
66 of FIG. 65, in accordance with the invention.
[0095] FIG. 67 is view in partial section of the membrane of FIGS.
65-66 illustrating a typical use in accordance with the
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0096] Although atrial fibrillation may result in the pooling of
blood in the left atrial appendage and the majority of use of the
invention is anticipated to be for the left atrial appendage, the
invention may also be used on the right atrial appendage and in
general for placement across any aperture in the body in which
blood clots are substantially prevented from escaping from the
cavity and entering into the bloodstream.
[0097] As shown in FIG. 4, a thrombus, blood clot, or emboli 30
(collectively referred to as a thrombus) may occur from pooling of
blood in the left atrial appendage 13 due to poor circulation of
blood therein when the patient experiences atrial fibrillation.
When blood pools in the left atrial appendage 13, thrombus 30 can
accumulate therein, build upon itself, and propagate out from the
left atrial appendage 13 into the left atrium 11, thus leaving the
heart and entering the blood stream. Once in the bloodstream, such
thrombus can block blood flow to the heart, brain, other organs, or
peripheral vessels if it becomes lodged in the arteries thereof.
Heart attack, a stroke, or ischemia may result.
[0098] To prevent thrombus 30 from forming in the left atrial
appendage 13, or to prevent thrombus formed therein from leaving
and entering the blood stream which may cause a heart attack, a
stroke or ischemia, a membrane 40 is permanently attached over or
across the ostium 20 of the atrial appendage 13. The membrane 40
can be made of bicompatible materials, such as, for example, ePFTE
(e.g., Gortex.RTM.), polyester (e.g., Dacron.RTM.), PTFE (e.g.,
Teflon.RTM.), silicone, urethane, metal fibers, or other
biocompatible polymers.
[0099] For each of the embodiments described hereinbelow, the
membrane 40 may be substantially impermeable with respect to the
flow of blood. For an impermeable membrane, neither blood nor
thrombus is permitted to flow through the membrane. As described
hereinabove, this structure prevents thrombus inside the atrial
appendage from entering the bloodstream and causing heart attack,
stroke, or ischemia. The impermeable membrane may be fabricated
from materials described above, such as polyurethane, polyester
(e.g., Dacron.RTM.), ePFTE (e.g., Gortex.RTM.) in textile, braid,
or substrate form. The impermeable membrane could also be comprised
of a combination of two or more materials. In some cases, the outer
periphery of the membrane may be supported by struts fabricated
from metal (e.g., stainless steel or nitinol) or plastic, or by
cells or braid. (See, e.g., FIGS. 20, 22, 24, 50, 56). This
additional structure may provide additional securement of the outer
periphery of the membrane against the atrial wall surrounding the
ostium in order to provide a leakproof seal.
[0100] According to another embodiment, each of the membrane
structures 40 described herein may alternatively be substantially
permeable with respect to the flow of blood therethrough. The
permeable membrane may also act as a filtering membrane in that it
will substantially inhibit thrombus from passing therethrough. The
permeable filtering membrane may have pore sizes ranging from about
50 to about 400 microns. It is also contemplated that the pores may
also be larger or smaller as indicated by the circumstances,
provided such pores substantially inhibit thrombus from passing
therethrough. The open area of the filtering membrane is preferably
at least 20% of the overall surface area, although a range of about
25-60% may be preferred. The structure of the filtering membrane is
preferably a two-dimensional screen, a cellular matrix, a woven or
non-woven mesh, or the like. The filtering membrane may also be a
permeable metal or a metal mesh of fine fibers. The filtering
membrane may be coated or covered with an anticoagulant, such as
heparin, or another compound, or treated to provide antithromogenic
properties.
[0101] The permeability of the filtering membrane, described above,
allows blood to flow therethrough while blocking or inhibiting the
passage of thrombus, clots, or emboli formed within the atrial
appendage from entering the atrium of the heart and, eventually,
the patient's bloodstream.
[0102] The characteristic of allowing the flow of blood through the
filtering membrane provides several advantages. For example, the
left atrial appendage inherently contracts during normal cardiac
function to force blood through the heart. These contractions
result in blood flow through the ostium of the left atrial
appendage. Allowing blood flow through the filtering membrane
substantially reduces any pressure gradient that may exist between
the appendage and the atrium.
[0103] The reduction of the pressure gradient may be helpful to the
patient during recovery from the implantation of the filtering
membrane structure in the atrial appendage. More particularly, the
heart is able to more gradually adapt to the presence of the
filtering membrane when blood is permitted to flow through the
membrane, and consequently through the ostium of the left atrial
appendage.
[0104] The filtering function may also reduce the risk of leakage
about the periphery of the filtering membrane, or of dislodgement
of the filtering membrane that may result from the exertion of
pressure against the surface of the filtering membrane. Allowing
the blood flow across the filtering membrane may relieve this
pressure, sufficiently and in a controlled manner, to reduce such
leakage or dislodgement.
[0105] Tissue ingrowth may provide additional securement of the
filtering membrane to the ostium. More particularly, the growth of
tissue may occur along the outer periphery of the filtering
membrane or supporting structure adjacent the ostium This tissue
growth, in cooperation with the pressure relief provided by the
permeable structure, may provide additional means of reducing
leakage about the periphery of the filtering membrane. Tissue
growth may eventually cover additional surface area of the
filtering membrane.
[0106] The membrane 40 placed across or over the ostium 20 should
be antithrombotic. In order to make the membrane antithrombotic,
heparin or other anticoagulants or antiplatelet agents may be used
on the membrane 40.
[0107] When permeable filtering membranes 40 are used, an ingrowth
of cells may eventually cover the membrane with endothelial cells.
The endothelial cells present a smooth cellular wall covering the
membrane which prevents thrombosis from occurring at the
membrane.
[0108] FIGS. 1 and 2 show a cross section of a human heart showing
a thrombus 30 in the left atrial appendage 13. The figures also
show the atrial appendage ostium 20 which is to have a membrane 40
placed over it to prevent the thrombus 30 from escaping out of the
atrial appendage 13 into the left atrium 11 and thus into the blood
stream, which could cause a stroke, a heart attack or ischemia.
[0109] FIG. 3 shows a cross section of a human heart showing a
thrombus 30 in the right atrial appendage 23. The right atrial
appendage 23 can be treated in the same manner as the left atrial
appendage 13.
[0110] FIG. 4 shows a cross section of the left atrium 11, the
ostium 20 and the left atrial appendage 13 having a thrombus 30
therein
[0111] FIG. 5 shows a delivery catheter 125 containing a collapsed
membrane 40 and a collapsed disk 130 connected to the membrane 40
by a spring 90 on catheter 21. The disk 130 may be made of a
flexible woven metal or a flexible woven metal with a thin
permeable polymer sandwiched inside. Disk 130 may also be a polymer
weave. The disk 130 is flexible and compresses or folds so it fits
into the delivery catheter 125 and expands to its desired shape
after release from the delivery catheter 125. Similarly, membrane
40 compresses or folds to fit into the delivery catheter 125 and
expands to its desired shape after release. Membrane 40 is larger
than the ostium 20. FIG. 6 shows the membrane 40, disk 130 and
spring 90 from FIG. 5 in an expanded configuration outside of the
delivery catheter 125.
[0112] FIG. 6 shows the spring 90 connecting the membrane 40 and
the disk 130 for urging them together. In other embodiments an
elastic tether or a tether with teeth and a pawl on the membrane 40
to form a ratchet can also be used to pull the membrane 40 and the
disk 130 together. Since membrane 40 is larger than the ostium 20,
the outer periphery of membrane 40 is in contact with the atrial
wall surrounding the ostium.
[0113] FIG. 7 shows the device of FIG. 5 applied to the left atrial
appendage 13 having thrombus 30. After the device is applied, the
spring 90 pulls the disk 130 toward the membrane 40, collapsing the
left atrial appendage 13 and trapping the thrombus 30 therein as
shown in FIG. 8. The spring 90 secures the outer periphery of the
membrane 40 in direct engagement with the atrial wall surrounding
the ostium 20.
[0114] FIG. 9 shows an alternate embodiment of the device in FIGS.
7 and 8 wherein the catheter 21 is equipped with a vacuum 140 for
sucking out blood and thrombosis 30 found in the left atrial
appendage 13. The vacuum 140 will help collapse the left atrial
appendage 13 such that spring 90 need not be as large as in FIG.
7.
[0115] FIGS. 10-12 show another embodiment of the invention using
an umbrella principle for securing the membrane 40 against the
ostium 20. FIG. 10 shows closed umbrella struts 160 entering the
ostium 20 of left atrial appendage 13. The membrane 40 is some
distance back from the umbrella struts 160 at the bottom of the
range of teeth 195 on pole 170. FIG. 11 shows the umbrella struts
inside of the left atrial appendage 13 with the struts 160 open.
Umbrella opening structure 175 on pole 170 pushes the struts out to
the umbrella open position. The umbrella opening structure 175 can
be pushed to the open position or have a spring loaded mechanism to
push the struts 160 to the open position. The ends of the umbrella
struts 160 engage the left atrial appendage wall around the ostium
20 and prevent the umbrella from being withdrawn from the left
atrial appendage 13. The ends of the umbrella struts 160 that
engage the atrial appendage wall may be blunted or have bulbs on
the tips or have padding so as not to puncture the left atrial
appendage 13. FIG. 12 shows the outer periphery of membrane 40
drawn up against the atrial wall surrounding the ostium 20 by
ratcheting the membrane along pole 170. The pawl mechanism 200
engages teeth 195 on pole 170 and is moved forward to snugly
position the membrane 40 across the ostium 20 such that the outer
periphery of the membrane 40 is in direct engagement with the
atrial wall surrounding the ostium.
[0116] FIG. 13 shows the left atrial appendage 13 compressed such
that the volume of the atrial appendage is reduced to almost
nothing. With the volume reduced the atrial appendage will not have
a large volume of blood which can produce a thrombus. In the
embodiment shown disk 130 and spring 90 pull the left atrial
appendage 13 toward membrane 40. Although FIG. 13 shows the use of
a disk 130 and spring 90 to act on the left appendage, any method
to reduce the volume of the atrial appendage as much as possible
may be used.
[0117] As shown in FIG. 13 the membrane 40 is much larger than the
ostium 20. The oversized membrane 40 may alternatively be used in
all embodiments to ensure that the ostium 20 is completely covered.
The spring 90 secures the outer periphery of the membrane 40 in
direct engagement with the atrial wall surrounding the ostium 20.
The membrane 40 has a structure which blocks or substantially
inhibits thrombus, clots or emboli from entering the atrium, and
eventually, the bloodstream of the patient.
[0118] FIGS. 14-18 show another embodiment of the invention wherein
the outer periphery of the membrane 40 is secured in direct
engagement with the atrial wall surrounding the ostium 20 by an
expandable structure, such as balloon structure 402. As illustrated
in FIG. 15, balloon structure 402 may be manufactured from
polymeric materials or similar materials known in the art. Tube 404
communicates with the internal cavity of balloon structure 402 for
introducing saline or other appropriate fluid into the balloon
structure 402. Membrane 40 is attached to tube 404 in any
appropriate manner, such as adhesive, sutures, or other means, and
is provided with an aperture 406 which permits access to an end
portion of tube 404, which acts as a balloon introduction port 408
to allow the introduction of fluid into the balloon structure
402.
[0119] FIG. 14 also illustrates a structure for introducing fluid
into the balloon structure 402, such as catheter apparatus 410.
Catheter apparatus 410 includes an outlet port 412 at its distal
end portion for ejecting fluid from the catheter apparatus 410.
Outlet port 412 may be connected to the balloon introduction port
408, which in turn communicates with the internal lumen of tube 404
and the interior of balloon structure 402.
[0120] FIG. 15 illustrates the membrane 40, the balloon structure
402, the tube 404, together with the catheter 410 attached to the
tube 404, in a compacted configuration within a delivery tube 422.
More particularly, balloon structure 402 is in its collapsed state
and membrane 40 is flexible and compressed or folded to fit into
the delivery tube 422. Membrane 40 is designed to expand into a
disc-like shape after release from tube 422. FIG. 16 illustrates
the certain structures pertinent to the interconnection of catheter
410 with tube 404. More particularly, outlet port 412 of catheter
410 may be provided with narrow tube 424 which is received within
balloon introduction port 408 and maintains a valve 426 in an open
position when outlet port 412 is connected to inlet port 408. When
outlet port 412 is removed from balloon introduction port 408,
valve 426 may close to prevent fluid from leaving balloon structure
402, as shown in FIG. 16.
[0121] Delivery tube 422 may be introduced into the venous or
arterial system at an appropriate location, and advanced to into
the atrium of the heart with appropriate steering and visualization
apparatus (not shown).
[0122] FIG. 17 illustrates a later stage in the installation
procedure wherein the membrane 40, the balloon structure 402, the
tube 404, and the catheter 410 have been advanced from the delivery
tube 422 (not shown in FIG. 17). The balloon structure 402 is
positioned within the left atrial appendage 13 such that the outer
periphery of membrane 40 is positioned adjacent the atrial wall
surrounding the ostium 20. Fluid is subsequently introduced into
the catheter 410 which passes through tube 404 to expand the
balloon structure 402, as illustrated in FIG. 18. The balloon
structure 402 expands within the atrial appendage 13 and secures
the membrane 40 in position. The valve mechanism 426 (not shown in
FIG. 18) of balloon introduction port 408 prevents the fluid from
passing out of the balloon structure 402 when the catheter 410 is
detached from the balloon port 408 and subsequently removed from
the atrium. As described above, membrane 40 may have an impermeable
structure which prevents thrombus for exiting the atrial appendage
13, but which also prevents blood flow through the membrane 40.
Membrane 40 may alternatively be a permeable structure which allows
blood to flow therethrough but which blocks or substantially
inhibits thrombi, clots or emboli from exiting the atrial appendage
13; and entering the bloodstream of the patient.
[0123] FIGS. 19-31 illustrate yet another embodiment for attaching
the membrane across the ostium 20 of the left atrial appendage 13.
FIG. 19 illustrates the membrane 40, the attachment apparatus 440
for securing the membrane 40 across the ostium 20 of the atrial
appendage 13, and catheter apparatus 442 for installing the
attachment apparatus 440 and membrane 40. As FIG. 20 illustrates,
attachment apparatus 440 and membrane 40 may be initially in a
compacted configuration. Attachment apparatus 440 is preferably an
expandable tubular apparatus having an initial diameter 444 of
about 1-3 mm and an initial length 446 of about 0.5-6 cm.
Attachment apparatus is preferably manufactured from a flexible
material such as stainless steel, nitinol, nylon, polyester, PET,
or polyethylene. Attachment apparatus 440 may be expanded by an
expansion structure, such as balloon structure 452 or mechanical
expansion structures 472 or 482. Alternatively, attachment
apparatus 440 may be self-expanding, such that it is normally
biased in an expanded position, such as that described with respect
to FIG. 24, and deployed in a constrained position such as that
described with respect to FIG. 20. Apparatus for constraining the
self-expanding apparatus is typically a tube.
[0124] Membrane 40 is attached to attachment apparatus 440 at the
proximal end thereof, in a loosely fitted, somewhat conical
configuration and defines a central opening 448, which allows the
catheter 450 of catheter apparatus 442 to pass through membrane 40,
as will be described in greater detail herein. Alternatively,
membrane 40 may also cover a greater portion of the length 446 of
the attachment apparatus 440, or membrane 40 may cover the entire
attachment apparatus 440 in a substantially sock-like fashion.
Membrane 40 may be fabricated from a material that also has elastic
characteristics which may expand from a first size to a second
size.
[0125] Catheter 450 supplies expansion fluid, such as saline or
contrast medium, into expandable structure, such as balloon
structure 452, which is positioned within the interior lumen of
attachment apparatus 440 in order to radially expand attachment
apparatus 440 when it is positioned within the atrial appendage 13.
Balloon structure 452 may include a distal, atraumatic tip portion
454, e.g., a flexible helical coil or soft plastic tip.
[0126] FIGS. 21 and 23 illustrate planar developments of attachment
apparatus 440. The structure of attachment apparatus 440 preferably
allows the length 446 of the apparatus in its initial configuration
(FIG. 21) to remain substantially constant with respect to the
length 456 in its expanded configuration (FIG. 23). In order to
achieve this expansion while maintaining substantially constant
length, attachment apparatus 440 is provided with a configuration
having several serpentine segments 458, 460, and 462. Adjacent
serpentine segments are interconnected by a plurality of
longitudinal struts, e.g., rings 457 and 460 are interconnected by
struts 464 and rings 460 and 462 are interconnected by struts 466.
A plurality of members 470 at the distal end portion of apparatus
440 may provide an attachment point for the membrane 40. More
particularly, radial members 471 are configured to extend radially
outward (FIG. 22) to provide a location for attachment of the outer
periphery of membrane 40 and to provide a surface for attachment to
the atrial wall. As will be described herein, radial members 471
may be expanded to the radially outward configuration by an
expansion member such as a balloon. In one embodiment, the
materials or thickness of members 471 may be selected in order to
allow members 471 to expand to a greater extent than the rest of
the attachment member 440. Alternatively, members 471 may be
fabricated from a self-expanding material, such as, e.g., nitinol,
wherein members are normally biased in the radially outward
configuration.
[0127] FIG. 24 illustrates attachment member 440 in an expanded
configuration, wherein length 456 remains substantially constant
with respect to the length 446 of the configuration illustrated in
FIG. 30. Diameter 472 is substantially larger than diameter 444
(FIG. 20) in order to secure itself against the interior of the
atrial appendage 13 and to secure membrane 40 in direct engagement
with the atrial wall surrounding the ostium 20, as will be
described herein. Members 471 extend radially outward, and provide
structure to the outer periphery of membrane 40.
[0128] FIGS. 25-28 illustrate several embodiments of the membrane
40. As described above, catheter 450 passes through opening 458 in
membrane 40 in order to supply expansion fluid to expandable
balloon structure 452. After balloon structure 452 has expanded the
attachment apparatus 440 to the expanded configuration illustrated
in FIG. 24, it may be necessary to remove balloon structure 452 by
passing the balloon structure 452 proximally through membrane 40,
and more particularly, through opening 458. The embodiments of
membrane 40 illustrated in FIGS. 25-28 may facilitate the passage
of balloon structure 452, or other interventional devices
therethrough.
[0129] FIG. 25 illustrates membrane 40a having a composite
construction comprising filtering section 474a and elastic section
476a. The filtering section 474a is fabricated from a filtering
material that provides the function of filtering the blood to allow
the blood to pass therethrough while blocking or substantially
inhibiting the passage of clots, thrombus or emboli therethrough,
as described above. The elastic section 476a is fabricated from an
elastic material, e.g., silicone, urethane or other similar
material, that stretches to enlarge opening 458a to allow the
balloon structure 452 or other intervention devices, such as, e.g.,
wires, catheters or the like, to pass therethrough and to
subsequently return to its initial size. The initial size of
aperture 458a provides similar characteristic to inhibit clots,
thrombus or emboli from passing through 458a as filtering material
of filtering section 474a. In this configuration, elastic material
476a extends substantially across the entire diameter 472a of the
membrane 40a.
[0130] Membrane 40b (FIG. 26) is constructed with a filtering
section 474b (i.e., the same material as filtering section 474a)
and an elastic section 476b (i.e., the same elastic material as
elastic section 476a). In membrane 40b, the filtering section 474b
substantially concentrically surrounds the elastic section 476b.
The elastic section 476b is provided with an opening 458b that
expands to allow the balloon structure 452 or other interventional
devices to pass therethrough and to return to initial size in order
to provide substantially the same characteristic of inhibiting the
passage of thrombus, clots and emboli from passing therethrough as
the filtering material of the filtering section 474b.
[0131] Membrane 40c (FIG. 27) is constructed with a filtering
section 474c (i.e., the same material as filtering section 474a)
and an elastic section 476c (i.e., the same elastic material as
elastic section 476a). In membrane 40c, the filtering section 474c
substantially concentrically surrounds an elastic section, such as
substantially elliptical section 476c. The elastic section 476c is
provided with an aperture, such as a slit 458c that expands to
allow the balloon structure 452 or other interventional devices to
pass therethrough and to return to initial size to provide
substantially the same characteristic of inhibiting the passage of
thrombus, clots and emboli from passing therethrough as the
filtering material of the faltering section 474b.
[0132] Membrane 40d (FIG. 28) may be fabricated from the same
material as filtering section 474a, above, in several sections,
such as sections 475d and 477d, which overlap at region 479d to
form an opening therethrough for balloon structure 452 or other
interventional devices. It is further contemplated that three or
more sections of filtering material may be used in an overlapping
configuration, in a manner similar to, for example, the "aperture"
configuration of an optical device. The balloon structure 452 may
be passed through the opening between sections 475d and 477d. After
the balloon structure 452 is removed, the overlapping structure
substantially closes the opening and provides substantially the
same characteristic of inhibiting the passage of thrombus, clots
and emboli from passing therethrough as the filtering material of
the filtering sections 475d and 477d.
[0133] FIGS. 29-31 illustrate the procedure for installing
attachment apparatus 440 and membrane 40 in the atrial appendage
13. In an initial step (FIG. 29), balloon structure 452, along with
attachment apparatus 440 are inserted into the atrial appendage 13
in its initial, compact configuration. In FIG. 30, expansion fluid
is passed through catheter 450 and exits through port 453 to fill
the interior of balloon structure 452. Balloon structure 452
expands, thereby radially enlarging attachment apparatus 440, as
described with respect to FIGS. 21-24, above. In a preferred
embodiment, proximal portion 455 of balloon 452 is constructed to
expand to a greater extent in order to deflect members 471 radially
outward. Alternatively, members 471 may be constructed to expand to
a greater extent than the rest of the attachment member 440 when
expanded by balloon 452. In another embodiment, members 471 may be
fabricated from a self-expanding material, such as, e.g., nitinol,
wherein members 471 are normally biased in the radially outward
configuration. Consequently, the outer periphery of membrane 40 is
expanded to be in direct contact with the atrial wall surrounding
the ostium 20. Members 471 provide additional support to provide a
good seal with the edge of the membrane 40.
[0134] As illustrated in FIG. 31, attachment apparatus 440 engages
the interior of the atrial appendage 13, thereby securing the
membrane 40 in position across the ostium 20, such that the outer
periphery of membrane 40 is in direct engagement with the atrial
wall surrounding the ostium 20. Balloon structure 452 may be
removed from the atrial appendage 13 by returning the balloon
structure 452 to its initial compact configuration (e.g., by
draining the expansion fluid therefrom) and withdrawing the balloon
structure proximally through opening 458. As described above with
respect to FIGS. 25-28, the membrane may be fabricated with an
elastic portion which expands to permit the withdrawal of the
balloon structure therethrough, and which subsequently reduces in
size to inhibit the passage of thrombi, clots and emboli
therethrough into the atrium. The catheter structure 442 may be
subsequently removed from the patient. Alternatively, the balloon
structure 452 may remain within the atrial appendage 13 following
expansion of attachment apparatus 440 and subsequent return of the
balloon structure 452 to its initial compact configuration. For
example, catheter 450 may be detachable from balloon structure 452
in a manner similar to the configuration of catheter 410 and tube
404 (FIG. 16). Alternatively, attachment structure 440 may be
manufactured from a self-expanding material, such as nitinol,
wherein attachment structure is normally biased in a configuration
such as that shown in FIG. 24. In order to install the attachment
structure 440 within the atrial appendage 13, the attachment
structure 440 may be constrained in a tube. The attachment
structure 440 may subsequently be deployed from the tube and
permitted to self-expand to a configuration similar to that shown
in FIG. 31.
[0135] FIGS. 32-34 illustrate another embodiment of the invention.
Attachment apparatus 460 and balloon apparatus 462 are
substantially the same as attachment apparatus 440 and balloon
apparatus 452, described hereinabove, with the differences noted
below. Attachment apparatus 460 may be provided with a plurality of
engagement members 464, such as prongs, hooks, or the like, in
order to engage and/or pierce the wall of the atrial appendage to
provide additional securement of the attachment apparatus 460.
Balloon structure 452 may be used in connection with attachment
apparatus 460. Alternatively, balloon structure 462 may be provided
having a distal end portion which is configured to expand to a
greater extent than the proximal portion thereof (FIG. 33). This
greater expansion of the balloon structure 462 provides additional
force in the area of the engagement members 464 to drive them into
the wall of the atrial appendage 13 (FIG. 34).
[0136] FIGS. 35-36 illustrate additional embodiments of expandable
structures for radially enlarging the attachment apparatus 440 (or
460) within the atrial appendage. Instead of, or in addition to
balloon structures (such as balloon structure 452), it is also
contemplated that mechanical expansion structures may be
particularly useful. FIGS. 35(a)-(b) illustrate a mechanical
expansion structure 472 which may be used to radially expand
attachment apparatus 440. As shown in FIG. 35(a), mechanical
expansion structure 472 may have a compact configuration wherein a
plurality of contact members 474 define a diameter 476 that enables
the structure to be inserted within the attachment apparatus 440.
As illustrated in FIG. 35(b), mechanical expansion structure 472
also has an expanded configuration, wherein contact members 474 are
further spaced apart to define a larger diameter 477 which radially
enlarges the attachment apparatus to the configuration illustrated
in FIGS. 21-24 and 30-31. A linkage configuration may include
linkage members 478 and sleeve 479. Sleeve 479 is provided with
internal threading (not shown) which engages external threading 480
on a portion of drive screw 481. Angular rotation of drive screw
481 (as indicated by the arrow) provides longitudinal movement of
sleeve 479 which cooperates with linkage members 478 to
controllably move the contact members 474 between the compact and
expanded configurations.
[0137] FIG. 36 illustrates mechanical expansion structure 482,
which is substantially identical to mechanical expansion structure
472. Sleeve 489 interacts with linkage members 478 to controllably
move contact members 474, as described above with respect to sleeve
479. Sleeve 489 is longitudinally slidable with respect to
elongated member 491. A locking structure (not shown) may also be
provided to fix the position of sleeve 489 (and thus contact
members 474) with respect to elongated member 491.
[0138] Mechanical expansion structures 472 and 482 may remain in
the atrial appendage 13 following the expansion of attachment
apparatus 440 (or 460). A portion of the drive screw 481 or
elongated member 491 may be detachable from the expansion
structures 472 or 482, respectively (not shown). Alternatively,
apparatus substantially similar to mechanical expansion structures
472/482 may be useful as supporting structures for membrane 40.
According to this embodiment, membrane 40 may be attached to an end
portion of structure 472/482, e.g., by attaching membrane 40 to end
portions of contact members 474 or by substantially enclosing
contact members 474 and linkage members 478. The structure 472/482
may be positioned in the atrial appendage 13 and expanded as
described above, such that membrane 40 extends across the ostium 20
to allow blood to pass therethrough while inhibiting the passage of
thrombus through the membrane 40. Drive screw 481 or elongated
member 491 may be subsequently detached from the apparatus
472/482.
[0139] FIGS. 37-39 illustrate another embodiment of the invention.
Membrane 40 may be installed in the atrial appendage 13 and held
therein by attachment apparatus 500, which preferably consists of a
pair of flexible wire portions 502a and 502b, which are preferably
constructed of a material such as nitinol or Elgiloy or stainless
steel and having a wire diameter of approximately 0.005 to 0.020
inch. Each wire portion 502a/502b may include a curved portion
504a/504b, a pair of support members 506a/506b and a plurality of
engagement members 508. The curved portions 504a/504b define a
substantially closed portion for mounting the membrane 40. The
membrane 40 is attached with sutures, adhesive, or other
appropriate means. The engagement members 508 are configured to
engage the interior of the atrial appendage 13 to secure the
membrane 40 in position across the ostium 20, as will be described
herein. The engagement members 508 may be provided with atraumatic
end portions 510.
[0140] FIG. 40 illustrates attachment apparatus 500 and membrane 40
in a compacted configuration for installation in the atrial
appendage 13. Preferably, a delivery catheter apparatus 520 is used
to introduce the attachment apparatus 500 and membrane 40 to the
atrial appendage. The curved portions 504a/504b are deflected
proximally toward parallelism with the longitudinal axis of the
catheter 520, and the engagement members 508 are deflected distally
toward parallelism with the longitudinal axis. An inner member 522
is slidably received within the interior of catheter 520 and may be
moved relatively longitudinally with respect to catheter apparatus
520 in order to deploy and install the attachment apparatus 500 and
membrane 40.
[0141] FIGS. 41-43 illustrated several options for installing the
membrane across the ostium 20. As illustrated in FIG. 50, the
curved portions 504a/504b are positioned within the walls of the
ostium 20 itself. The engagement members 508 provide additional
support by engaging the interior of the atrial appendage.
Alternatively, the curved portions 504a/504b are positioned outside
the ostium within the atrium. Engagement members 508 retain the
outer periphery of membrane 40 in direct engagement with the atrial
wall surrounding the ostium 20. According to yet another
alternative embodiment, engagement member 508 are provided with
sharpened barb end portions 512 which engage and/or pierce the wall
of the atrial appendage to secure the membrane in position (FIG.
43).
[0142] FIGS. 44-45 illustrate another embodiment of the invention.
Attachment apparatus 650 provides a first plurality of strut wires
652 that extend distally and radially outward from a support ring
654 toward the distal end portion 656 of the attachment apparatus
650, and a second plurality of strut wires 658 that extend
proximally and radially outward from support ring 654 toward the
proximal end portion 660. The strut wires 652/658 may be
constructed from an alloy, such as nitinol, having shape memory
characteristics. The support ring 654 maintains the strut wires
652/658 in the proper configuration and may be made of radiopaque
materials, such as, e.g., platinum to provide fluoroscopic imaging
of the device position. The strut wires 652 may be provided with
barbs 662 or other methods for attachment to the interior of the
atrial appendage. The struts 652/658 are configured to engage the
walls of the ostium on the inner and outside sides thereof,
respectively.
[0143] The strut wires 658 may serve as a membrane mounting
structure. The membrane 40 is attached to strut wires 658 and
provides the characteristics described above. In one embodiment,
the membrane 40 is permeable wherein blood is allowed to pass
through the membrane 40, but thrombi, clots, and emboli are
inhibited from passing therethrough. Alternatively, the membrane 40
may be impermeable to the flow of thrombus as well as blood. The
membrane 40 may be connected to the strut wires 602 using adhesive,
sutures, encapsulation or other means.
[0144] Another embodiment of the invention is illustrated in FIG.
46. Attachment apparatus 670 is constructed of braided or woven
mesh material rather than the strut wires 652/658 described with
respect to FIGS. 44-45. The distal portion 672 is configured to
engage the wall of the atrial appendage adjacent the inner portion
of the ostium, and the proximal portion 676 is configured to engage
the outer portion of the ostium, and the neck portion 674 is
disposed therebetween. The braided or woven self-expanded mesh
material of attachment apparatus 670 has similar filtering
characteristics as membrane 40, or alternatively, a membrane is
attached to the mesh material to provide those characteristics.
[0145] FIGS. 47-48 illustrate apparatus for delivering and
installing the attachment apparatus 650 and membrane 40 and/or
attachment apparatus 670. The catheter apparatus 620 includes an
outer sheath 622 and an inner member 624 slidably received within
the interior of outer sheath 622. The outer sheath 622 and inner
member 624 may be fabricated from materials, such as polymers, that
are sufficiently flexible to negotiate the anatomy, yet
sufficiently rigid for relative longitudinal movement to deploy and
position the attachment apparatus 600. Inner member 624 may have a
distal end portion 626 and a shoulder portion 628. Strut wires 652
of apparatus 650 (or distal portions 672 of apparatus 670) are
deflected distally toward parallelism with the longitudinal axis of
the catheter device 620 and retained in the deflected configuration
by the outer sheath 622. Similarly, strut wires 658 (or proximal
portions 676) are deflected proximally toward parallelism with the
longitudinal axis and retained in this configuration by the outer
sheath 622. In order to deploy the attachment apparatus 600, the
outer sheath 622 is moved longitudinally relative to the inner
member 626. The shoulder portion 628 retains the attachment
apparatus 650/670 in position. Upon retraction of the outer sheath
622, the shape memory characteristics of the strut wires 652/658
(or portions 672/676) cause the apparatus to return to a shape
approximating that of FIG. 44 (or FIG. 46).
[0146] FIGS. 49-50 illustrate the installation of attachment
apparatus 650/670 and membrane 40 in greater detail. As illustrated
in FIG. 49, the catheter device 622 is advanced partially within
the atrial appendage 13. The outer sheath 622 may be retracted
proximally, which permits the strut wires 652 to extend radially
outwardly. The physician may use the radiopaque characteristics of
the ring 654 in order to properly position the ring 654 within the
ostium 20. Further proximal retraction of the outer sheath 622
allows the distal strut wires 652 and the proximal strut wires 658
to extend radially outward and engage the interior of the atrial
appendage 13 (FIG. 50). The barbs 662 may engage and/or pierce the
wall of the atrial appendage to provide increased stability of the
attachment apparatus 600. The membrane 40 is consequently
positioned across the ostium 20 such that the outer periphery of
membrane 40 is secured in direct engagement with the atrial wall
surrounding the ostium. In one embodiment, the membrane 40 is
impermeable and does not permit blood or thrombus to flow, whereas
a filtering membrane may be used to allow blood to pass through the
membrane, while substantially inhibiting thrombi, clots, and emboli
from exiting the atrial appendage 13. Struts 658 provide additional
securement in order to maintain a leakproof seal between membrane
40 and the atrial wall surrounding the ostium 20.
[0147] FIGS. 51-52 illustrate yet another embodiment of the
invention. Attachment apparatus 700 provides a plurality of strut
wires 702 that extend radially outward from a support ring 704. A
first portion 706 of each strut wire 702 extends towards the
proximal end portion 708 of the attachment apparatus 700, and a
second portion 710 of each strut wire 702 extends towards the
distal end portion 712. The distal portion 710 of each strut wire
702 may be provided with a sharpened barb tip 714 or other methods
for attachment to the interior of the atrial appendage. The strut
wires 702 are constructed from an alloy, similar to material used
for strut wires 602, above. The support ring 704 maintains the
strut wires 702 in the proper configuration and is substantially
similar to support ring 604, above. The proximal portions 706 and
distal portions 710 of strut wires 702 are configured to engage the
walls of the ostium on the outer and inner sides thereof,
respectively.
[0148] The membrane 40 is attached to proximal portions 706 of
strut wires 702 and may provides the filtering characteristic
described above, wherein blood is allowed to pass through the
membrane 40, but thrombi, clots, and emboli are inhibited from
passing therethrough. Alternatively, membrane 40 may be impermeable
to both blood and thrombi. The membrane 40 may be connected to the
strut wires 702 using adhesive, sutures, encapsulation or other
means.
[0149] FIGS. 53-54 illustrate apparatus for delivering and
installing the attachment apparatus 700 and membrane 40. The
catheter apparatus 620 is described above with respect to FIGS.
47-48. Strut wires 702 are deflected towards parallelism with the
longitudinal axis of the catheter device 620 and retained in the
deflected configuration by the outer sheath 622. In order to deploy
the attachment apparatus 700, the outer sheath 622 is moved
longitudinally relative to the inner member 626. The shoulder
portion 628 retains the attachment apparatus 700 in position. Upon
retraction of the outer sheath 622, the shape memory
characteristics of the strut wires 702 causes the apparatus to
resume the shape approximating that of FIG. 51.
[0150] FIGS. 55-56 illustrate the installation of attachment
apparatus 700 and membrane 40 in greater detail. As illustrated in
FIG. 55, the catheter device 622 is advanced partially within the
atrial appendage 13. The outer sheath 622 may be retracted
proximally, which permits the distal portions 710 of strut wires
702 to extend radially outwardly. Further proximal retraction of
the outer sheath 622 allows the distal portions 710 to engage the
interior of the atrial appendage 13 and the proximal portions 706
to engage the outer portion of the ostium 20 (FIG. 56). Struts 706
provide additional securement in order to maintain a leakproof seal
between membrane 40 and the atrial wall surrounding the ostium 20.
The barbs 714 may engage and/or pierce the wall of the atrial
appendage to provide increased stability of the attachment
apparatus 700. The membrane 40 is consequently positioned across
the ostium 20, such that the outer periphery of the membrane is
secured in direct engagement with the atrial wall surrounding the
ostium 20. Struts 706 provide additional securement of the membrane
to the atrial wall to provide a leakproof seal. A court order
should be obtained in order to allow blood to pass through the
membrane, while substantially inhibiting thrombi, clots, and emboli
from exiting the atrial appendage 13.
[0151] FIGS. 57-58 illustrate additional embodiments of the
invention. Attachment apparatus 750 includes a plurality of strut
wires 752 that extend radially outward and distally from a support
member 754 towards the distal end portion 756. Each strut wire 752
may be provided with a sharpened barb tip 758 or other methods for
attachment to the interior of the atrial appendage. The strut wires
702 are constructed from an alloy, similar to the material used for
strut wires 602, above. The support member 754 maintains the strut
wires 752 in the desired configuration.
[0152] The proximal end portion of support member 754 supports a
curved membrane mounting structure 760 that defines a substantially
closed curve. The membrane 40 is attached to membrane mounting
structure 760 and may provide the filtering characteristic
described above, wherein blood is allowed to pass through the
membrane 40, but thrombi, clots, and emboli are inhibited from
passing therethrough. The membrane 40 may alternatively be
impermeable to blood flow and the passage of thrombi. The membrane
40 may be connected to the membrane mounting structure 760 using
adhesive, sutures, encapsulation or other means.
[0153] The attachment apparatus 770, illustrated in FIG. 58 is
substantially identical to attachment apparatus 750, with the
differences noted herein. For example, the proximal end portion of
support member 754 supports a membrane mounting structure 772
having a spiral configuration. The membrane 40 is attached to
spiral mounting structure 772 substantially as described above with
respect to membrane mounting structure 760, above. The spiral
configuration may, e.g., assist in reducing the mounting structure
to a compacted configuration during installation.
[0154] FIGS. 59-60 illustrate the installation of attachment
apparatus 750 (or 770) and membrane 40 in the atrial appendage 13.
Catheter apparatus 780 is provided for delivering and installing
the attachment apparatus 750 and membrane 40. The catheter
apparatus 780 is similar to catheter apparatus 620 described above
with respect to FIG. 55. Catheter apparatus 780 includes an outer
sheath 782 and an inner member 784. Inner member 784 preferably has
an engagement surface 785 on a distal end portion thereof. During
installation, strut wires 752 are deflected towards parallelism
with the longitudinal axis of the catheter device 780 and retained
in the deflected configuration by the outer sheath 782 (not shown
in FIG. 59). Similarly, the membrane mounting portion 760 (or 772)
is folded, rolled or otherwise compacted inside outer sheath 782 as
illustrated in FIG. 59.
[0155] In order to deploy the attachment apparatus 750, the
catheter device 780 is advanced partially within the atrial
appendage 13. The outer sheath 782 may be retracted proximally,
which permits the strut wires 752 to extend radially outwardly due
to its shape memory characteristics, as shown. The inner member 784
retains the attachment apparatus 750 in position.
[0156] As illustrated in FIG. 60, further proximal retraction of
the outer sheath 782 allows the strut wires 752 to extend radially
outward and engage the interior of the atrial appendage. The barbs
758 may engage and/or pierce the wall of the atrial appendage to
provide increased stability of the attachment apparatus 700. The
membrane mounting structure 760 (or 772) is likewise permitted to
return to its disc-like configuration, such that membrane 40 is
positioned across the ostium 20 such that the outer periphery of
the membrane 40 is secured in direct engagement with the atrial
wall surrounding the ostium. The membrane 40 may be permeable in
order to allow blood to pass through the membrane, while
substantially inhibiting thrombi, clots, and emboli from exiting
the atrial appendage 13. Alternatively, the membrane 40 may be
impermeable to blood flow and the passage of thrombus.
[0157] FIGS. 61-67 illustrate additional embodiments of the
invention wherein membrane 40 is sized to cover the ostium 20 of
the atrial appendage and secured in direct engagement with the
atrial wall surrounding the ostium. Membrane 40 is thus provided
with a diameter or other dimension that is larger than the diameter
or corresponding dimension of the ostium 20 in order to entirely
cover the ostium. More particularly, membrane 40 defines an outer
periphery which is secured in direct engagement with the ostium or
the atrial wall surrounding the ostium.
[0158] As illustrated in FIGS. 61-62, membrane 40 is provided with
a plurality of engagement members 400, which may be attached to and
positioned about the outer periphery of membrane 40, and which may
have shank portions 402 and barbed free ends 404 which in this case
may extend radially outward from the engagement members 400.
[0159] As shown in FIG. 63, membrane 40 is installed to cover
ostium 20. Engagement members 400 pierce the wall of the ostium 20
or the atrial wall surrounding the ostium to attach the membrane 40
directly to the ostium 20 or the atrial wall surrounding the
ostium. Barbed free ends 404 prevent the engagement members 400
from being withdrawn from the wall, and assists in securing the
membrane 40 in position as shown in the FIG. Membrane 40 has a
structure which blocks thrombus from leaving the atrial appendage
and entering the bloodstream. A filtering permeable membrane may
alternatively be used, which allows blood to flow through while
substantially inhibiting thrombus.
[0160] FIG. 64 illustrates another embodiment wherein the membrane
40 covers the ostium 20 of the atrial appendage 13. A biocompatible
tissue adhesive 420, such as fibrin glue or cyanoacrylate or a
similar material, may be applied about the outer periphery of the
membrane and used to attach the membrane 40 directly to the ostium
20 or the wall of the atrium surrounding the ostium 20. Membrane 40
blocks thrombus from leaving the atrial appendage and entering the
bloodstream. A filtering permeable membrane may alternatively be
used, which allows blood to flow through while substantially
inhibiting thrombus.
[0161] FIGS. 65-66 illustrate still another embodiment of the
invention wherein membrane 40 is provided with a plurality of
engagement members 430. Each of engagement members 430 is mounted
about the periphery of membrane 40, and has an elongated shank
portion 432 that extends distally longitudinally and a barbed free
end 434 that may extend radially outward from the elongated shank
portion 432. Shank portion 432 is substantially longer than shank
portions 402 described above with respect to FIGS. 61-63.
Engagement members 430 define a spacing 436, or the distance
between opposite engagement members 430, exclusive of the radial
projection of the barb-like free ends 434, that is similar in size
to the interior dimensions of the ostium 20. This spacing 436
between engagement members 430 located on opposite sides of the
membrane 40 provides the feature of centering the engagement
members within the interior of the ostium 20 and the atrial
appendage 13.
[0162] As shown in FIG. 67, membrane 40 is installed to cover
ostium 20. Elongated shank portions 432 extend a distance into the
ostium 20 or the atrial appendage 13 and assist in centering the
membrane 40 within the ostium 20. Barbed free ends 434 engage the
interior wall of the atrial appendage 13 to prevent the engagement
members 430 from being withdrawn from the wall, and secure the
membrane 40 in direct engagement with the ostium 40 or the atrial
wall surrounding the ostium 40 as shown in the FIG. Membrane 40 has
a structure which blocks thrombus from leaving the atrial appendage
and entering the bloodstream. A filtering permeable membrane may
alternatively be used, which allows blood to flow through while
substantially inhibiting thrombus.
[0163] The devices described above may be percutaneously delivered
to the left and right atrial appendages 13, 23 respectively. The
devices may have materials in them which enhance visualization or
imaging by ultrasound, x-ray or other means making it easier for
the device to be implanted and accurately centered with respect to
the ostium 20 of the atrial appendage 13. This may consist of small
beads placed strategically on the membrane, the connecting
elements, or on the anchors. Referring to FIG. 1 catheter 21 is
seen entering the heart by way of the aorta 12 to the left
ventricle 16 passing through the mitral valve 17 and then entering
the left atrial appendage 13 to apply the membrane 40 in one of the
embodiments as disclosed above. In FIG. 2 the catheter 21 enters
the heart from the femoral vein, passes through the inferior vena
cava 18 to the right atrium and then passes through the fossa
ovalis 19 or through the septum 29 into the left atrium 11 and then
approaches the left atrial appendage 13 to apply the membrane 40
thereto. FIG. 3 shows the catheter 21 being applied to the right
atrial appendage 23. Catheter 21 may enter the heart through the
jugular vein 28 or the femoral vein to the inferior vena cava
18.
[0164] It is understood that the invention may be practiced with
numerous means of attaching the membrane 40 across the ostium 20 of
the atrial appendages 13 and 23. All of the above embodiments shown
and discussed for the left atrial appendage 13 are also useable on
the right atrial appendage 23. Any combination of the attachment
means with adhesives, prongs, cylindrical structures, anchors,
disks, tethers or springs may be used. The membrane may penetrate
the atrial appendage and provide a means to securely lock the
membrane device into place. If permeable characteristics are
preferred by the physician, other means of providing a membrane for
allowing blood flow therethrough and substantially inhibiting blood
clots from exiting out of the atrial appendages not listed herein
may also be used.
[0165] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that, within the scope of the appended
claims, the invention may be practiced otherwise than as
specifically described.
* * * * *