U.S. patent application number 10/364910 was filed with the patent office on 2003-11-27 for method of containing embolic material in the left atrial appendage.
Invention is credited to Cicco, Dino De, Frazier, Andrew G. C., Khairkhahan, Alexander K., Kreidler, Marc S., Lesh, Michael D., Roue, Chad C., van der Burg, Erik J..
Application Number | 20030220667 10/364910 |
Document ID | / |
Family ID | 29552793 |
Filed Date | 2003-11-27 |
United States Patent
Application |
20030220667 |
Kind Code |
A1 |
van der Burg, Erik J. ; et
al. |
November 27, 2003 |
Method of containing embolic material in the left atrial
appendage
Abstract
Disclosed are methods and devices for containing embolic
material within a left atrial appendage of a patient. The device is
deployed such that a barrier substantially obstructs the passage of
embolic material from the left atrial appendage. The barrier may be
self expandable, and may include a polymeric or wire mesh. The
device may additionally include a plurality of tissue engagement
members, for engaging tissue.
Inventors: |
van der Burg, Erik J.;
(Sunnyvale, CA) ; Cicco, Dino De; (San Jose,
CA) ; Frazier, Andrew G. C.; (Sunnyvale, CA) ;
Khairkhahan, Alexander K.; (Palo Alto, CA) ;
Kreidler, Marc S.; (Sunnyvale, CA) ; Lesh, Michael
D.; (Mill Valley, CA) ; Roue, Chad C.;
(Fremont, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
29552793 |
Appl. No.: |
10/364910 |
Filed: |
February 11, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10364910 |
Feb 11, 2003 |
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09435562 |
Nov 8, 1999 |
|
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09435562 |
Nov 8, 1999 |
|
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09187200 |
Nov 6, 1998 |
|
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6152144 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61B 2017/081 20130101;
A61B 2017/00579 20130101; A61B 2017/00867 20130101; A61F 2230/008
20130101; A61F 2230/0006 20130101; A61F 2230/0071 20130101; A61M
2025/1054 20130101; A61B 17/0057 20130101; A61B 2017/00619
20130101; A61B 17/12186 20130101; A61B 2017/00243 20130101; A61B
2017/00557 20130101; A61B 17/12031 20130101; A61F 2/01 20130101;
A61B 17/12172 20130101; A61B 2017/00632 20130101; A61F 2002/018
20130101; A61M 2210/125 20130101; A61F 2230/0069 20130101; A61B
2017/00601 20130101; A61B 17/12136 20130101; A61B 17/12195
20130101; A61B 2017/00597 20130101; A61B 2017/00575 20130101; A61B
17/122 20130101; A61B 2017/1205 20130101; A61B 2017/00592 20130101;
A61B 2017/00615 20130101; A61M 25/10 20130101; A61B 17/12022
20130101; A61B 17/12122 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 029/00 |
Claims
What is claimed:
1. A method of containing embolic material within a left atrial
appendage of a patient, comprising: a) providing a containment
device comprising a barrier for preventing the escape of embolic
material from the left atrial appendage; b) providing a delivery
catheter having a proximal end and a distal end; c) advancing the
delivery catheter through the patient's vasculature to position the
containment device within the patient's left atrium; and d)
deploying the containment device such that the barrier
substantially obstructs the passage of embolic material from the
left atrial appendage.
2. A method of containing embolic material as in claim 1, wherein
the barrier comprises a mesh.
3. A method of containing embolic material as in claim 1, wherein
the barrier comprises polyethylene.
4. A method of containing embolic material as in claim 2, wherein
the mesh comprises polyethylene.
5. A method of containing embolic material as in claim 1, wherein
the barrier comprises a polymer film.
6. A method of containing embolic material as in claim 1, wherein
the barrier comprises a polymer mesh.
7. A method of containing embolic material as in claim 1, wherein
the barrier comprises a nickel titanium alloy.
8. A method of containing embolic material as in claim 1, wherein
the barrier comprises stainless steel.
9. A method of containing embolic material as in claim 1, wherein
the barrier comprises ePTFE.
10. A method of containing embolic material as in claim 1, wherein
the barrier comprises Dacron.
11. A method of containing embolic material as in claim 1, where
the barrier comprises nylon.
12. A method of containing embolic material as in claim 1, wherein
the barrier has a pore size of no greater than about 0.04
inches.
13. A method of containing embolic material as in claim 1, further
comprising the step of removing thrombotic or fibrotic material
from the patient's left atrial appendage prior to deployment of the
containment device.
14. A method of containing embolic material as in claim 13, wherein
the thrombotic or fibrotic material is removed from the patient's
left atrial appendage by aspiration through an aspiration lumen of
a catheter having a port in the distal end thereof in fluid
communication with the aspiration lumen which is operatively
connected at its proximal end to a vacuum source.
15. A method of containing embolic material as in claim 1, wherein
the containment device comprises an expandable member configured to
engage an inside surface of the left atrial appendage and the
containment device is at least partially deployed by expanding the
expandable member within the left atrial appendage so as to engage
at least a portion of an inner surface of the left atrial
appendage.
16. A method of containing embolic material as in claim 1, wherein
the barrier comprises a self expandable frame.
17. A method of containing embolic material as in claim 16, further
comprising a mesh on the frame.
18. A method of containing embolic material as in claim 17, wherein
the mesh comprises a polymer selected from the group consisting of
Dacron, Nylon, TFE, PTFE, ePTFE, polyethylene and polyurethane.
19. A method of containing embolic material as in claim 1, wherein
the containment device is self expandable.
20. A method of containing embolic material as in claim 1, wherein
the containment device comprises a self expandable wire
structure.
21. A method of containing embolic material as in claim 1, wherein
the advancing step comprises advancing the delivery catheter
through the femoral vein.
22. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises wire mesh.
23. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises braided wire.
24. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises wire coil.
25. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises shape memory
material.
26. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises pseudoelastic
alloy.
27. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises nickel titanium
alloy.
28. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises stainless steel.
29. A method of containing embolic material as in claim 20, wherein
the self expandable wire structure comprises composite
material.
30. A method of treating the left atrial appendage of a patient,
comprising the steps of: providing a delivery catheter having a
proximal end and a distal end, and a self expandable wire structure
for acting as a barrier to the passage of embolic material from the
left atrial appendage, removeably carried by the distal end;
advancing the delivery catheter into the patient's left atrium;
positioning the self expandable wire structure at the left atrial
appendage; and deploying the self expandable wire structure such
that it substantially obstructs the passage of embolic material
from the left atrial appendage.
31. The method of claim 30, further comprising the step of removing
thrombotic or fibrotic material from the patient's left atrial
appendage prior to deployment of the self expandable wire
structure.
32. The method of claim 31, wherein the thrombotic or fibrotic
material is removed from the patient's left atrial appendage by
aspiration through an aspiration lumen of a catheter having a port
in the distal end thereof in fluid communication with the
aspiration lumen which is operatively connected at its proximal end
to a vacuum source.
33. The method of claim 30, wherein the deploying step comprises
deploying the self expandable wire structure such that it engages
at least a portion of an inner surface of the left atrial
appendage.
34. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises wire mesh.
35. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises braided
wire.
36. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises wire coil.
37. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises shape memory
material.
38. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises pseudoelastic
alloy.
39. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises nickel
titanium alloy.
40. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises stainless
steel.
41. A method of treating the left atrial appendage as in claim 30,
wherein the self expandable wire structure comprises composite
material.
42. A method as in claim 30, further comprising a barrier on the
wire structure.
43. A method as in claim 42, wherein the barrier comprises a
polymer selected from the group consisting of Dacron, Nylon, TFE,
PTFE, ePTFE, polyethylene and polyurethane.
44. A method as in claim 43, wherein the barrier has a pore size of
up to about 0.04 inches.
45. A method as in claim 30, wherein the advancing step comprises
advancing the delivery catheter through the right femoral vein.
46. A method as in claim 30, wherein the advancing step comprises
advancing the delivery catheter to the left atrial appendage
intraoperatively.
47. A method as in claim 30, wherein the self expandable wire
structure comprises a plurality of tissue engagement members, and
the method further comprises the step of engaging tissue with the
tissue engagement members.
48. A method as in claim 1, wherein the containment device
comprises a plurality of tissue engagement members, and the method
further comprises the step of engaging tissue with the tissue
engagement members.
Description
[0001] This is a continuation application of U.S. patent
application Ser. No. 09/435,562 filed on Nov. 8, 1999 which is a
continuation-in-part of U.S. patent application Ser. No.
09/187,200, filed Nov. 6, 1998, now U.S. Pat. No. 6,152,144, the
disclosures of which are incorporated in their entirety herein by
reference.
BACKGROUND OF THE INVENTION
[0002] Embolic stroke is the nation's third leading killer for
adults, and is a major cause of disability. There are over 700,000
strokes per year in the United States alone. Of these, roughly
100,000 are hemoragic, and 600,000 are ischemic (either due to
vessel narrowing or to embolism). The most common cause of embolic
stroke emanating from the heart is thrombus formation due to atrial
fibrillation. Approximately 80,000 strokes per year are
attributable to atrial fibrillation. Atrial fibrillation is an
arrhythmia of the heart that results in a rapid and chaotic
heartbeat that produces lower cardiac output and irregular and
turbulent blood flow in the vascular system. There are over five
million people worldwide with atrial fibrillation, with about four
hundred thousand new cases reported each year. Atrial fibrillation
is associated with a 500 percent greater risk of stroke due to the
condition. A patient with atrial fibrillation typically has a
significantly decreased quality of life due, in part, to the fear
of a stroke, and the pharmaceutical regimen necessary to reduce
that risk.
[0003] For patients who develop atrial thrombus from atrial
fibrillation, the clot normally occurs in the left atrial appendage
(LAA) of the heart. The LAA is a cavity which looks like a small
finger or windsock and which is connected to the lateral wall of
the left atrium between the mitral valve and the root of the left
pulmonary vein. The LAA normally contracts with the rest of the
left atrium during a normal heart cycle, thus keeping blood from
becoming stagnant therein, but often fails to contract with any
vigor in patients experiencing atrial fibrillation due to the
discoordinate electrical signals associated with AF. As a result,
thrombus formation is predisposed to form in the stagnant blood
within the LAA.
[0004] Blackshear and Odell have reported that of the 1288 patients
with non-rheumatic atrial fibrillation involved in their study, 221
(17%) had thrombus detected in the left atrium of the heart.
Blackshear J L, Odell J A., Appendage Obliteration to Reduce Stroke
in Cardiac Surgical Patients With Atrial Fibrillation. Ann Thorac.
Surg., 1996.61(2):755-9. Of the patients with atrial thrombus, 201
(91%) had the atrial thrombus located within the left atrial
appendage. The foregoing suggests that the elimination or
containment of thrombus formed within the LAA of patients with
atrial fibrillation would significantly reduce the incidence of
stroke in those patients.
[0005] Pharmacological therapies for stroke prevention such as oral
or systemic administration of warfarin or the like have been
inadequate due to serious side effects of the medications and lack
of patient compliance in taking the medication. Invasive surgical
or thorascopic techniques have been used to obliterate the LAA,
however, many patients are not suitable candidates for such
surgical procedures due to a compromised condition or having
previously undergone cardiac surgery. In addition, the perceived
risks of even a thorascopic surgical procedure often outweigh the
potential benefits. See Blackshear and Odell, above. See also
Lindsay B D., Obliteration of the Left Atrial Appendage: A Concept
Worth Testing, Ann Thorac. Surg., 1996.61(2):515.
[0006] Despite the various efforts in the prior art, there remains
a need for a minimally invasive method and associated devices for
reducing the risk of thrombus formation in the left atrial
appendage.
SUMMARY OF THE INVENTION
[0007] There is provided in accordance with one aspect of the
present invention, a method of containing embolic material within a
left atrial appendage of a patient. The method comprises the steps
of providing a containment device comprising a barrier for
preventing the escape of embolic material from the left atrial
appendage. A delivery catheter is provided, having a proximal end
and a distal end. The delivery catheter is advanced through the
patient's vasculature to position the containment device within the
patient's left atrium. The containment device is deployed such that
the barrier substantially obstructs the passage of embolic material
from the left atrial appendage. In one implementation of the
invention, the barrier comprises a mesh. The barrier may comprise
polyethylene. Alternatively, the barrier may comprise a nickel
titanium alloy, or other materials disclosed herein. The barrier
may comprise a self expandable frame, and may further carry a mesh
on the frame. The self expandable frame may comprise a wire
mesh.
[0008] In accordance with another aspect of the present invention,
there is provided a method of treating the left atrial appendage of
a patient. The method comprises the steps of providing a delivery
catheter having a proximal end and a distal end, and a self
expandable wire structure for acting as a barrier to the passage of
embolic material from the left atrial appendage, removably carried
by the distal end. The delivery catheter is advanced into the
patient's left atrium. The self expandable wire structure is
positioned at the left atrial appendage, and the self expandable
wire structure is deployed such that it substantially obstructs the
passage of embolic material from the left atrial appendage.
[0009] The method may additionally comprise the step of removing
thrombotic or fibrotic material from the patient's left atrial
appendage prior to deployment of the self expandable wire
structure. The deploying step may comprise deploying the self
expandable wire structure such that it engages at least a portion
of an inner surface of the left atrial appendage. The self
expandable wire structure may comprise wire mesh. The self
expandable wire structure may comprise a plurality of tissue
engagement members, and the method further comprises the step of
engaging tissue with the tissue engagement members.
[0010] Further features and advantages of the present invention
will become apparent to those of ordinary skill in the art in view
of the detailed description of preferred embodiments which follows,
when considered together with the attached drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a perspective view of an embodiment having
features of the invention with an occluding member and a retention
member.
[0012] FIG. 2 shows an end view of the apparatus of FIG. 1 in
partial section.
[0013] FIG. 3 shows a longitudinal cross-sectional view of the
apparatus of FIGS. 1 and 2.
[0014] FIG. 3A shows a perspective view of an apparatus having
features of the invention.
[0015] FIG. 3B shows an elevational view in partial section of the
apparatus of FIG. 3A.
[0016] FIG. 4 shows an elevational view of an apparatus having
features of the invention in a deployed state within a body
cavity.
[0017] FIG. 5 shows an elevational view of an apparatus having
features of the invention in a deployed state within a body
cavity.
[0018] FIG. 6 shows a perspective view of an apparatus for sealing
off a body cavity having features of the invention.
[0019] FIG. 7 shows an elevational view in partial section of an
apparatus for sealing off a body cavity having features of the
invention.
[0020] FIG. 8 shows a transverse cross-sectional view of the
apparatus of FIG. 7 taken along lines 8-8.
[0021] FIG. 9 shows a schematic view of a patient's heart with a
transeptal catheter deployed through the septum and a delivery
catheter and apparatus for sealing off a body cavity disposed
therein.
[0022] FIG. 10 shows a schematic view of a patient's heart in
partial section with a delivery catheter disposed within the
opening of the LAA.
[0023] FIG. 11 shows a magnified view of the delivery catheter
distal end and the LAA of a patient of FIG. 10 with an apparatus
for sealing off a body cavity partially deployed within the
LAA.
[0024] FIG. 12 shows the apparatus for sealing off a body cavity of
FIG. 11 fully deployed within a LAA.
[0025] FIG. 13 shows an elevational view of a device for occluding
a body cavity having features of the invention.
[0026] FIG. 14 shows a transverse cross sectional view of the
device for occluding a body cavity of FIG. 13 taken along lines
14-14.
[0027] FIG. 15 shows a device for occluding a body cavity having
features of the invention deployed within a LAA.
[0028] FIG. 16 shows a device for occluding a body cavity having
features of the invention deployed within a LAA.
[0029] FIG. 17 shows a LAA being occluded by a method having
features of the invention.
[0030] FIG. 18 shows a LAA occluded by method having features of
the invention.
[0031] FIG. 19 shows a LAA occluded by method having features of
the invention.
[0032] FIG. 20 is an elevational view of an apparatus for closing
an interior body cavity of a patient in partial section having
features of the invention.
[0033] FIG. 21 is a schematic view of an apparatus for closing an
interior body cavity of a patient in contact with tissue of a
LAA.
[0034] FIG. 22 is a schematic view of an apparatus for closing an
interior body cavity of a patient in contact with tissue of a
LAA.
[0035] FIG. 23 shows a LAA which has been closed by a method having
features of the invention.
[0036] FIG. 24 is a perspective view of an occlusion device in
accordance with the present invention.
[0037] FIG. 25 is a side elevational view of the occlusion device
shown in FIG. 24.
[0038] FIG. 26 is a perspective view of an alternate embodiment of
the present invention.
[0039] FIG. 27 is a side elevational view of the embodiment shown
in FIG. 26.
[0040] FIG. 28 is a perspective view of a further embodiment of the
present invention.
[0041] FIG. 29 is a side elevational view of the embodiment of FIG.
28.
[0042] FIG. 30 is a perspective view of a further occlusion device
in accordance with the present invention.
[0043] FIG. 31 is an end view taken along the line 31-31 of FIG.
30.
[0044] FIG. 32 is a schematic illustration of an inflatable balloon
positioned within the occlusion device of FIG. 30.
[0045] FIG. 33 is a schematic view of a pull string deployment
embodiment of the occlusion device of FIG. 30.
[0046] FIGS. 34A and 34B are side elevational schematic
representations of partial and complete barrier layers on the
occlusion device of FIG. 30.
[0047] FIG. 35 is a side elevational schematic view of an alternate
occlusion device in accordance with the present invention.
[0048] FIG. 36 is a schematic view of a bonding layer mesh for use
in forming a composite barrier membrane in accordance with the
present invention.
[0049] FIG. 37 is an exploded cross sectional view of the
components of a composite barrier member in accordance with the
present invention.
[0050] FIG. 38 is a cross sectional view through a composite
barrier formed from the components illustrated in FIG. 37.
[0051] FIG. 39 is a top plan view of the composite barrier
illustrated in FIG. 38.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0052] FIGS. 1-3 show an embodiment of an occluding device 10
having features of the invention where an occluding member 11 is
secured to a retention member 12 that is arranged to fix the
occluding member in a desired position within a body passageway or
cavity. The occluding member 11 generally has disc shape with an
outer rim 13 around the perimeter of a frame structure 14 which
supports a barrier 15. The outer rim 13 can be circular or
polygonal, or any other shape that is suitable for conforming to
the inside surface of a body cavity. A hub 16 can be located near
the center of the occluding member 11 which serves to connect the
retention member 12 to the occluding member, in addition to other
functions. The outer rim 13 is typically made from a soft polymer
material 17 which permits flexibility of the outer rim and
facilitates sealing of the outer rim against the inside surface of
a body cavity or passageway. The barrier 15 can be a thin mesh or
film of material which serves to block the passage of material
within an area surrounded by the outer rim 13. The barrier 15 can
be secured to the outer rim 13 along its entire perimeter 18 in
order to achieve a complete seal therebetween and can be molded
into the outer rim 13 or bonded thereto by a suitable method such
as gluing, welding, sewing or other suitable method.
[0053] The outer rim 13 is at least partially supported by the
frame structure 14 which connects the outer rim and the hub. The
frame structure 14 can be made from one or more elements of high
strength material such as stainless steel or MP35N, or may
preferably be made from shape memory or pseudoelastic alloys such
as NiTi, or any of a variety of known structural biodegradable
materials (e.g. polyglycolic acid, poly lactic acid, poly-L-lactic
acid and derivatives or copolymers such as PLGA). Preferably, the
frame structure 14 is made from a material which can be
self-expanding from a constrained configuration so that the
occluding device 10 can be delivered to the deployment site in a
low profile an flexible configuration which facilitates
percutaneous delivery.
[0054] Preferably a radial hoop 21 is contained within the soft
polymer material 17 of the outer rim 13 and serves to maintain the
annular shape of the outer rim and facilitate radial expansion of
the outer rim from a constrained position or configuration. The
radial hoop 21 may be isolated within the soft polymer material 17
of the outer rim 13, or may be connected to at least some of the
elements 22 of the frame structure 14, in order to have stronger
mechanical joint between the outer rim and the frame structure. The
radial hoop 21 is shown in a substantially circular configuration,
but may also be polygonal or otherwise suitably shared, and may
have connections or joints spaced thereon to facilitate contraction
or folding of the device for non-invasive delivery.
[0055] In addition to connecting the retention member 12 and the
occluding member 11, the hub 16 may serve to house a rotational
coupling 23 which is connected to the proximal end 24 of a tissue
penetrating shaft 25 within the retention member. The rotational
coupling 23 allows the transfer of torque to the tissue penetrating
shaft 25 which preferably has a helically shaped extension or
distal extremity 26 which is configured to screw into tissue and be
mechanically fixed thereto. Longitudinal movement of the tissue
penetrating shaft 25 relative to the retention member 12 and hub 16
may be prevented by sizing a lumen 27 of the retention member which
contains the tissue penetrating shaft such that the helically
shaped extension 26 at the distal end is too large to pass through
the lumen and the proximal end 24 of the tissue penetrating shaft
is prevented from passing through the lumen by the rotational
coupling attached thereto. The rotational coupling 23 may also be
configured to be longitudinally captured by the hub 16 but still be
rotatably disposed therein.
[0056] FIGS. 3A and 3B depict an alternative embodiment of an
occluding device 10 having an occluding member 11 and a retention
member 12. The retention member 12 has a shaft 28 and radially
extending members 29 extending radially from a proximal end of the
shaft. The radially extending members 29 serve to anchor the shaft
28 and the occluding member 11 by engaging the tissue surrounding
the occluding device. Preferably, the radially extending members
are self-expanding from a constricted state and are made of a
pseudo elastic alloy such as NiTi, or a high strength material such
as stainless steel. Although it is preferable for the radially
extending members 29 to be self-expanding from a constricted state,
they may also be expanded by use of shape memory properties or a
radial outward force as would be provided by an inflatable balloon
or the like. The shaft 28 can be a single element or made of
multiple elements, and can be made from the same materials as the
radially extending members or different materials such as polymers
or polymer composites. The radially extending members 29 have a
proximally directed bias at their radial extremities 29A so that
the members readily fold down and move easily in a distal direction
during insertion of the occluding device 10, but spring outward and
aggressively engage surrounding tissue upon movement in a proximal
direction. This configuration of the radially extending members 29
allows easy insertion into a body cavity, but prevents egress of
the device 10 in and outward or proximal direction.
[0057] FIG. 4. depicts an occluding device 30 similar to that
depicted in FIGS. 1-3 deployed within the left atrial appendage 31
of a patient. An outer rim or periphery 32 of the occluding device
30 is disposed adjacent the opening 33 of the left atrial appendage
31 in a position which allows for a substantial seal of the outer
rim against the inside surface 34 of the LAA. A helically shaped
distal extremity 35 of a tissue penetrating shaft 36 has been
screwed into the wall tissue of the LAA and is mechanically secured
thereto. A retention member 38 maintains the position of an
occluding member 41 in a substantially perpendicular orientation
with respect to a longitudinal axis of the LAA 42.
[0058] FIG. 5 depicts an occluding device similar to that depicted
in FIGS. 1-4 deployed within a LAA 51 of a patient similar to what
is shown in FIG. 4. The structure of an occluding member 52 of the
embodiment as shown in FIG. 5 differs from that shown in FIG. 4 in
that a barrier 53 and frame structure 54 of the embodiment of FIG.
5 protrudes proximally from a plane defined by an outer rim 55.
This configuration may be useful for certain morphologies of
patient's LAAs. One object of the invention is to create a smooth
surface outside the body passageway or cavity in order to prevent
turbulent flow or eddies of blood or other bodily fluid within the
cavity or passageway. The alternative configuration of the
occluding device 50 shown in FIG. 5 may be useful in this
regard.
[0059] FIG. 6 shows an alternative embodiment of an occluding
device 60 which has an occluding member 61, a frame structure 62, a
barrier 63 and a retention member in the form of an expandable
member 65 which has linked elements 66 that are preferably
expandable from a constrained configuration. The expandable member
65 is generally cylindrical in shape and can have a series of
circumferential linked elements 66 connected by links 68. Although
FIG. 6 depicts the expandable member 65 as a series of linked
elements 66, those skilled in the art will realize that a similar
effect can be achieved with a single wire in a helical
configuration or a plurality of wires in a mesh or braided
configuration, or any other suitable configuration that can be
self-expanding from a constrained configuration or expanding with
the application of heat or other form of energy or force. For
example, the expandable member 65 may be configured to be deployed
by an outward radial force delivered from within the expandable
member. An inflatable balloon or the like could be used to exert
such a force. The expandable member is preferably secured to an
outer rim 71 of the occluding member 61 but may also be secured to
the frame structure 62 directly or indirectly. The expandable
member 65 can be self-expanding from a constrained configuration as
can the occluding member 61 and the frame structure 62 and outer
rim 71 thereof. The frame structure 62, outer rim 71 and barrier 63
may have construction similar to that described above with regard
to the similar elements of the embodiments depicted in FIGS.
1-5.
[0060] Referring to FIG. 7, the expandable member 65 as shown in
FIG. 6 may also have a sheath 72 disposed around it so as to act as
a shield between the expandable member and an inner surface of a
patient's body cavity or passageway. The sheath 72 may facilitate
the sealing function of the occluding member 61, but is primarily
intended to prevent damage to either tissue on the inside surface
of a body cavity or to the linked elements 66 of the expandable
member. The sheath 72 may surround all or part of the expandable
member 65 and may be made from a variety of suitable biocompatible
materials such as Dacron.RTM., Nylon, TFE, PTFE or ePTFE. The
sheath 72 may be a weave, braid, film or have any other suitable
configuration. Expandable member 65 may also be coated by dipping,
spraying, or other suitable process with a friction reducing
material such as Teflon.RTM., or with an active compound such as
heparin.
[0061] FIG. 8 shows a transverse cross-sectional view of the
embodiment of FIG. 7 taken at lines 8-8. The frame structure 62 has
an axis or hub 73 disposed at approximately the center of the frame
structure which serves to connect the various radial elements 74 of
the frame structure. The hub 73 can have an independent structure
that links the several elements 74 of the frame structure 62 or it
may be merely the terminus of the various frame structure elements
and have a solid composition. In either structure, the hub 73
preferably allows a constrained configuration of the occluding
member 61 to facilitate percutaneous delivery of the occluding
device 60. The hub 73 may also have a lumen disposed therein to
allow passage of a guidewire of other guiding member. Preferably,
the lumen would have a self sealing valve or gasket which prevents
the passage of fluid or embolic material once the guidewire or
guiding member is removed from the lumen.
[0062] Referring to FIG. 9, a schematic view of a patient's heart
80 in partial section shows a trans-septal catheter 81 having a
proximal end 82 and a distal end 83. The distal end 83 of the
trans-septal catheter 81 is disposed within a patient's heart 80
with the distal end 84 of a delivery catheter 85 extending from the
distal end 83 of the trans-septal catheter. The distal end 83 of
the trans-septal catheter 81 has breached the septum 86 of the
patient's heart 80 and is disposed adjacent the opening of the
patient's LAA 88. At the proximal end 82 of the trans-septal
catheter 81 there is a Luer connector 91 coupled to a hemostasis
valve 92 which prevents the egress of blood from a lumen 93 of the
trans-septal catheter 81. The proximal end 94 of the delivery
catheter 85 extends proximally from the hemostasis valve 92 and has
a Luer connector 95 attached to the proximal extremity thereof. The
proximal end 96 of, a plunger 97 extends from the Luer connector 95
of the delivery catheter. The proximal end 94 of the delivery
catheter is arranged to allow rotational and axial movement of the
plunger 97 while preventing blood or other bodily fluids from
leaking between the delivery catheter 85 and the plunger 97.
[0063] Referring to FIG. 10, a patient's heart 80 is shown in
partial section with the distal end 84 of a delivery catheter 85
disposed within the LAA opening 87. FIG. 11 is a magnified view of
the LAA 88 shown in FIG. 10 and the distal end of the delivery
catheter 84, which is shown in partial section, contains a plunger
97 which is slideably disposed within an inner lumen 98 of the
delivery catheter 85 and serves to apply axial force in a distal
direction on the collapsed occluding member 101 disposed within the
delivery catheter so as to force the occluding device 102 from the
delivery catheter and deploy it. An occluding device 102 having an
expandable member 103 and an occluding member 101 secured thereto
is partially deployed and extending from the distal end of the
delivery catheter 84 into the patient's LAA 88. The occluding
device 102 can also be guided into the patient's LAA 88 by use of
an appropriate guidewire or guiding member.
[0064] FIG. 12 shows the occluding device 102 of FIG. 11 in a
deployed state within the patient's LAA 88. An outer rim 104 of the
occluding member 101 is in substantial sealing contact with the
inside surface 105 of the LAA 88. The expandable member 103 has
expanded so as to contact the inside surface 105 of the LAA and
secure the occluding device 102 thereto and maintain the occluding
member 101 in a substantially perpendicular orientation relative to
a longitudinal axis 106 of the LAA 88. A barrier 107 is disposed
within an area bounded by the outer rim 104 and is positioned to
prevent the passage or embolic or other material to or from the LAA
88. The distal end 108 of the plunger 97 is extending from the
distal end of the delivery catheter 84 after having pushed the
occluding device 102 from the delivery catheter.
[0065] Referring to FIG. 13, an occluding device 110 having
features of the invention is shown. The occluding device 110 has a
delivery catheter 111 with a distal end 112, a detachment mechanism
113 disposed on the distal end of the delivery catheter and an
occlusive body or inflatable member 114 detachably secured to the
detachment mechanism. The inflatable member 114 has a proximal end
115 and a distal end 116 with the proximal end being attached to
the detachment mechanism 113 and the distal end terminating at an
end cap 117. The inflatable member 114 has an outside surface 118
that may contain a fibrosis inducing material such as Dacron.RTM.
or other similar materials. The inflatable member 114 may be made
from a fluid tight film of polymer material which can be either
compliant or non-compliant. Preferably the inflatable member 114 is
made from silicone, however, any suitable material such as
polyethylene, polyurethane or PET can be used.
[0066] The detachment mechanism 113 can be activated by mechanical
force or by delivery of thermal or optical energy by a suitable
conduit. Alternatively, the inflatable member can be pushed into
the LAA from the delivery catheter 111 by an elongate push member
without the use of a detachment mechanism. The inflatable member
114 can be filled with a gas, fluid or gel which is injected under
pressure through the delivery catheter 114 and into the inflatable
member. Suitable fluids to inject would include saline and
silicone. The inflatable member 114 may also be filled with a
polymer material that can be hardened. Autologus fluid such as
blood, or collagen may also be used. A fluid, gel or polymer used
to fill the inflatable member may contain contrast agents such as
gold, tantalum, bismuth, barium sulfate or the like in order to
improve visualization under fluoroscopy or x-ray imaging.
[0067] FIG. 14 is a transverse cross-sectional view of the
occluding device 110 of FIG. 13 taken along lines 14-14. An
optional inner shaft 121 is shown disposed within the inflatable
member 114, preferably in a concentric arrangement. The inner shaft
121 provides longitudinal axial support to the inflatable member
114 so as to maintain a longitudinal dimension of the inflatable
member 114 when it is being inflated and deployed. The inner shaft
121 may be solid or contain one or more lumens that may or may not
be in fluid communication with an inner lumen 122 of the inflatable
member 114, and can be used for the passage of a guidewire or
guiding member.
[0068] FIG. 15 depicts an alternative embodiment of an occluding
device 110 which consists of an inflatable member 114 similar to
the inflatable member of FIG. 13, shown substantially deployed,
within a patient's LAA 123. The inflatable member 114 has been at
least partially filled with a fluid, gas or gel within the
patient's LAA 123 such that the outside surface of the inflatable
member 118 is in contact with at least part of the inside surface
124 of the LAA. The inflatable member 114 can have rib members 125
which can mechanically interlock with the trebeculae 126 of the
inside surface of the LAA 124 or other surface irregularities of
the inside surface of a patient's body cavity or passageway. The
rib members 125 form a complete circumference of the inflatable
member 114, but could also form a partial circumference, spiral
configuration, or consist of random projections on the surface of
the inflatable member 118. The rib members 125 should extend
radially about 1 to about 4 mm from the nominal surface of the
inflatable member 114, and are preferably spaced about 3 to about 8
mm from each other. The rib members 125 may be made from any
suitable polymer material, but are preferably made from the same
material as the inflatable member, and are integrally molded
thereon, or bonded thereto with a heat weld or adhesive bond
suitable for bonding flexibly medical polymers. The inflatable
member 114 is depicted with the distal end of the delivery catheter
112 and detachment mechanism 113 attached. As an alternative, or in
addition to the polymer rib members 125 shown in FIG. 15, barbs or
hooks could be secured to the outside surface of the inflatable
member 114 which are configured to engage the inside surface of a
patient's LAA 124. Preferably, barbs or hooks disposed on the
outside surface of the inflatable member and configured to engage
the tissue of the inside surface of a patient's LAA 124 would have
a proximally directed bias at their radial extremity so that the
barbs would fold down and move easily in a distal direction during
insertion of the inflatable member 114, but would spring outward
and aggressively engage the tissue of the body cavity upon movement
in a proximal direction of the inflatable member.
[0069] FIG. 16 depicts an occluding device 110 consisting of an
inflatable member 114 which is shown deployed within a patient's
LAA 123. The embodiment of the inflatable member 114 shown in FIG.
16 has an optional retention member 127 with a tissue penetrating
shaft 128 which has a proximal 131 end and a distal end 132. A
rotational coupling 133 is disposed at the proximal end 131 of the
tissue penetrating shaft 128 and a helically shaped extremity 134
is disposed at the distal end of the shaft 132. The helically
shaped distal extremity 134 is shown deployed within and
mechanically engaging wall tissue 135 of the LAA so as to secure
the inflatable member 114 and maintain its position within the LAA
123 of the patient.
[0070] FIG. 17 shows an alternative embodiment of an occlusive
member 140 consisting of a polymer mass 141 which has been injected
or delivered into a patient's LAA 142. The distal end 143 of a
delivery catheter 144 has a lumen 145 therein which extends to a
proximal end of the delivery catheter which is in fluid
communication with a source of pressurized polymer material. A
source of pressurized polymer material 146 can be any type of pump
or device capable of forcing a polymer fluid or gel into the
proximal end of the delivery catheter with sufficient pressure to
force the polymer fluid or gel out the distal end 143 of the
delivery catheter 144 and into a patient's body cavity or
passageway. The delivery catheter 144 may be positioned by the
techniques discussed above, e.g., the Mullins trans-septal approach
or any other suitable method. Once the distal end of the delivery
catheter 143 is disposed within a desired portion of the patient's
LAA 142, the polymer mass 141 may be injected to fill the cavity to
the desired level. The LAA 142 can be completely or partially
filled with the polymer mass 141 which can be formulated to harden
over time, with heat or remain in a fluid or gel state. The distal
end of the delivery catheter can optionally include an expandable
member which is used to substantially seal the delivery catheter
against the inside surface of the opening of the patient's body
cavity during the delivery of polymer material. The expandable
member can be an inflatable balloon or the like which are well
known in the art.
[0071] Optionally, a retention member 127 having a tissue
penetrating shaft 128 or the like, such as shown in FIG. 16 with
regard to the inflatable member 114, may be deployed within the LAA
142 prior to injection of the polymer mass 141 and captured thereby
so as to secure the polymer mass within the LAA. Alternatively, the
polymer mass can be used to fill the patient's LAA and surround and
secure a deployed device as shown in FIG. 4 or 5 in the patient's
LAA 142.
[0072] Once a desired amount of polymer mass 141 has been injected
into the LAA 142, as assessed for example by TE Echo imaging, the
delivery catheter 144 may be withdrawn and the procedure
terminated. Preferably, the entire LAA 142 of a patient is filled
with the polymer mass 141 as shown in FIG. 18 and hardens or gels
to maintain its shape. It may be desirable to have the polymer mass
141 retain a soft compressible form after setting or hardening so
that it is at least partially compliant with the constrictive
pumping action of a heart and resistant to fatigue as a result
thereof. A material used to form the polymer mass 141 may contain
contrast agents such as gold, platinum, tantalum, bismuth or the
like in order to better visualize the deployment of the polymer
mass under fluoroscopic or x-ray imaging.
[0073] Another alternative embodiment of an occlusive member 140
can be found in FIG. 19 which shows an occlusive coil 147 which has
been deployed within an LAA 142. The occlusive coil 147 as shown
has assumed a random configuration that is mechanically occluding
the LAA 142 and which has induced clot and/or fibrosis formation
148 which further facilitates occlusion of the LAA 142.
[0074] An apparatus for closing off a body cavity or passageway 150
is shown in FIG. 20 which has features of the present invention.
The apparatus 150 has an elongate shaft 151 with an inner lumen 152
and a proximal end 153 and a distal end 154. Slideably disposed
within the inner lumen 152 of the elongate shaft 151 are at least
two elongate members 155 which have proximal ends 156 and distal
ends 157 and have tissue attachment members 158 disposed on the
distal ends. An optional distal anchor member 161 is also slideably
disposed within the inner lumen 152 of the elongate shaft 151 and
preferably has a distal end 162 terminating with a helical member
163. The proximal end 153 of the elongate shaft 151 has a proximal
control module 164 which seals the inner lumen 152 of the elongate
shaft 151 and allows rotation and translation of the proximal ends
156 of the elongate members 155 and the distal anchor member 161
while maintaining a seal between said members to prevent leakage of
bodily fluids therefrom. The proximal control module 164 can
optionally be configured to control advancement and retraction of
the elongate members 155 and control activation of the tissue
attachment members 158.
[0075] FIG. 21 shows the apparatus for closing off a body cavity
150 of FIG. 20 with the distal ends of the elongate members 157 and
the tissue attachment members 158 extending distally from the
distal end of the elongate shaft 154. The distal ends of the
elongate members 157 are angled or deflected from a longitudinal
axis 165 of the elongate shaft 151 so as to engage tissue 166 of
the opening 167 of the LAA 168 as shown. The elongate members 155
may be deflected by an abutment or angulation contained in the
distal end of the elongate shaft 154, but are preferably preshaped
in an angled configuration which manifests when the distal ends are
freed of the constraint of the inner lumen 152 of the elongate
shaft an allowed to assume their relaxed preshaped condition. The
helical member 163 at the distal end 162 of the distal anchor
member 161 is engaged with the wall tissue 171 of the LAA 168 so as
to provide an optional anchor that can be used to move the elongate
shaft 151 relative to the distal anchor member 161 and give greater
control of the longitudinal axial movement of the elongate shaft
relative to the LAA opening 167. The tissue attachment members 158
are shown attached to the annular edge 172 of the LAA opening 167.
Once the tissue attachment members 158 are attached, a closure
member or retaining ring 173 may be advanced distally by applying
axial force on an elongate push shaft 174 which draws the tissue
attachment members 158 and the tissue attached thereto closer
together as shown in FIG. 22. As the closure member 173 is further
advanced distally, the annular edge of the LAA 172 is drawn closed,
and eventually, the annular edge of the LAA will be completely
closed into a closed state with the closure member 173 surrounding
and compressing the tissue of the annular edge as shown in FIG. 23.
Once a closed state of the LAA is achieved, the tissue attachment
members 158 may be detached, and the apparatus for closing off a
body cavity 150 withdrawn. One alternative method can have the
tissue attachment members 158 drawn together by retracting them
proximally into the distal end 154 of the elongate shaft 151 as
opposed to distally advancing the closure member 173 with the
elongate push shaft 174. In this way, the annular edge of the LAA
172 can be drawn into a closed state within the distal end 154 of
the elongate shaft 151 at which point the annular edge may be fixed
in the closed state by a variety of methods including suturing,
tissue welding, the application of a suitable biocompatible
adhesive, surgical staples or the like.
[0076] Referring to FIGS. 24 and 25, there is illustrated an
alternate embodiment of the occlusion device 10 in accordance with
the present invention. The occlusion device 10 comprises an
occluding member 11 comprising a frame 14 and a barrier 15. In the
illustrated embodiment, the frame 14 comprises a plurality of
radially outwardly extending spokes 17 each having a length within
the range of from about 0.5 cm to about 2 cm from a hub 16. In one
embodiment, the spokes have an axial length of about 1.5 cm.
Depending upon the desired introduction crossing profile of the
collapsed occlusion device 10, as well as structural strength
requirements in the deployed device, anywhere within the range of
from about 3 spokes to about 40 spokes may be utilized. In some
embodiments, anywhere from about 12 to about 24 spokes are
utilized, and, 18 spokes are utilized in one embodiment.
[0077] The spokes are advanceable from a generally axially
extending orientation such as to fit within a tubular introduction
catheter to a radially inclined orientation as illustrated in FIG.
24 and FIG. 25 following deployment from the catheter. In a
self-expandable embodiment, the spokes are biased radially
outwardly such that the occlusion member expands to its enlarged,
implantation cross-section under its own bias following deployment
from the catheter. Alternatively, the occlusion member may be
enlarged using any of a variety of enlargement structures such as
an inflatable balloon.
[0078] Preferably, the spokes comprise a metal such as stainless
steel, Nitinol, Elgiloy, or others which can be determined through
routine experimentation by those of skill in the art. Wires having
a circular or rectangular cross-section may be utilized depending
upon the manufacturing technique. In one embodiment, rectangular
cross section spokes are cut such as by known laser cutting
techniques from tube stock, a portion of which forms the hub
16.
[0079] The barrier 15 may comprise any of a variety of materials
which facilitate cellular in-growth, such as ePTFE. The suitability
of alternate materials for barrier 15 can be determined through
routine experimentation by those of skill in the art. The barrier
15 may be provided on either one or both sides of the occlusion
member. In one embodiment, the barrier 15 comprises two layers,
with one layer on each side of the frame 14. The two layers may be
bonded to each other around the spokes 17 in any of a variety of
ways, such as by heat bonding with or without an intermediate
bonding layer such as polyethylene or FEP, adhesives, sutures, and
other techniques which will be apparent to those of skill in the
art in view of the disclosure herein. The barrier 15 preferably has
a thickness of no more than about 0.003" and a porosity within the
range of from about 5 Pm to about 60 Pm.
[0080] The barrier 15 in one embodiment preferably is securely
attached to the frame 14 and retains a sufficient porosity to
facilitate cellular ingrowth and/or attachment. One method of
manufacturing a suitable composite membrane barrier 15 is
illustrated in FIGS. 36-39. As illustrated schematically in FIG.
36, a bonding layer 254 preferably comprises a mesh or other porous
structure having an open surface area within the range of from
about 10% to about 90%. Preferably, the open surface area of the
mesh is within the range of from about 30% to about 60%. The
opening or pore size of the bonding layer 254 is preferably within
the range of from about 0.005 inches to about 0.050 inches, and, in
one embodiment, is about 0.020 inches. The thickness of the bonding
layer 254 can be varied widely, and is generally within the range
of from about 0.0005 inches to about 0.005 inches. In a preferred
embodiment, the bonding layer 254 has a thickness of about 0.001 to
about 0.002 inches. One suitable polyethylene bonding mesh is
available from Smith and Nephew, under the code SN9.
[0081] Referring to FIG. 37, the bonding layer 254 is preferably
placed adjacent one or both sides of a spoke or other frame element
14. The bonding layer 254 and frame 14 layers are then positioned
in-between a first membrane 250 and a second membrane 252 to
provide a composite membrane stack. The first membrane 250 and
second 252 may comprise any of a variety of materials and
thicknesses, depending upon the desired functional result.
Generally, the membrane has a thickness within the range of from
about 0.0005 inches to about 0.010 inches. In one embodiment, the
membranes 250 and 252 each have a thickness on the order of from
about 0.001 inches to about 0.002 inches, and comprise porous
ePTFE, having a porosity within the range of from about 10 microns
to about 100 microns.
[0082] The composite stack is heated to a temperature of from about
200.degree. to about 300.degree., for about 1 minute to about 5
minutes under pressure to provide a finished composite membrane
assembly with an embedded frame 14 as illustrated schematically in
FIG. 38. The final composite membrane has a thickness within the
range of from about 0.001 inches to about 0.010 inches, and,
preferably, is about 0.002 to about 0.003 inches in thickness.
However, the thicknesses and process parameters of the foregoing
may be varied considerably, depending upon the materials of the
bonding layer 254 the first layer 250 and the second layer 252.
[0083] As illustrated in top plan view in FIG. 39, the resulting
finished composite membrane has a plurality of "unbonded" windows
or areas 256 suitable for cellular attachment and/or ingrowth. The
attachment areas 256 are bounded by the frame 14 struts, and the
cross-hatch pattern formed by the bonding layer 254. In the
illustrated embodiment, the filaments of the bonding layer 254 are
oriented in a nonparallel relationship with the struts of frame 14,
and, in particular, at an angle within the range of from about
15.degree. to about 85.degree. from the longitudinal axis of the
struts. Preferably, a regular window 256 pattern is produced.
[0084] The foregoing procedure allows the bonding mesh to flow into
the first and second membranes 250 and 252 and gives the composite
membrane 15 greater strength (both tensile and tear strength) than
the components without the bonding mesh. The composite allows
uniform bonding while maintaining porosity of the membrane 15, to
facilitate tissue attachment. By flowing the thermoplastic bonding
layer into the pores of the outer mesh layers 250 and 252, the
composite flexibility is preserved and the overall composite layer
thickness can be minimized.
[0085] The occlusion device 10 may be further provided with a
bulking element or stabilizer 194. The stabilizer 194 may be spaced
apart along an axis from the occluding member 11. In the
illustrated embodiment, a distal end 190 and a proximal end 192 are
identified for reference. The designation proximal or distal is not
intended to indicate any particular anatomical orientation or
deployment orientation within the deployment catheter. As shown in
FIGS. 24 and 25, the stabilizer 194 is spaced distally apart from
the occluding member 11.
[0086] For use in the LAA, the occluding member 11 has an expanded
diameter within the range of from about 1 cm to about 5 cm, and, in
one embodiment, about 3 cm. The axial length of the occluding
member 11 in an expanded, unstressed orientation from the distal
end 192 to the proximal hub 16 is on the order of about 1 cm. The
overall length of the occlusion device 10 from the distal end 192
to the proximal end 190 is within the range of from about 1.5 cm to
about 4 cm and, in one embodiment, about 2.5 cm. The axial length
of the stabilizer 194 between distal hub 191 and proximal hub 16 is
within the range of from about 0.5 cm to about 2 cm, and, in one
embodiment, about 1 cm. The expanded diameter of the stabilizer 194
is within the range of from about 0.5 cm to about 2.5 cm, and, in
one embodiment, about 1.4 cm. The outside diameter of the disial
hub 191 and proximal hub 16 is about 2.5 mm.
[0087] Preferably, the occlusion device 10 is provided with one or
more retention structures for retaining the device in the left
atrial appendage or other body lumen. In the illustrated
embodiment, a plurality of barbs or other anchors 195 are provided,
for engaging adjacent tissue to retain the occlusion device 10 in
its implanted position and to limit relative movement between the
tissue and the occlusion device. The illustrated anchors are
provided on one or more of the spokes 17, or other portion of frame
14. Preferably, every spoke, every second spoke or every third
spoke are provided with one or two anchors each. The illustrated
anchor is in the form of a barb, for extending into tissue at or
near the opening of the LAA.
[0088] One or more anchors 195 may also be provided on the
stabilizer 194, such that it assists not only in orienting the
occlusion device 10 and resisting compression of the LAA, but also
in retaining the occlusion device 10 within the LAA. Any of a wide
variety of structures may be utilized for anchor 195, either on the
occluding member 11 or the stabilizer 194 or both, such as hooks,
barbs, pins, sutures, adhesives and others which will be apparent
to those of skill in the art in view of the disclosure herein.
[0089] In use, the occlusion device 10 is preferably positioned
within a tubular anatomical structure to be occluded such as the
left atrial appendage such that the occluding member 11 is
positioned across or near the opening to the LAA and the stabilizer
194 is positioned within the LAA. The stabilizer 194 assists in the
proper location and orientation of the occluding member 11, as well
as resists compression of the LAA behind the occluding member 11.
The present inventors have determined that following deployment of
an occluding member 11 without a stabilizer 194 or other bulking
structure to resist compression of the LAA, normal operation of the
heart may cause compression and resulting volume changes in the
LAA, thereby forcing fluid past the occluding member 11 and
inhibiting or preventing a complete seal. Provision of a stabilizer
194 dimensioned to prevent the collapse or pumping of the LAA thus
minimize leakage, and provision of the barbs facilitates
endothelialization or other cell growth across the occluding member
11.
[0090] For this purpose, the stabilizer 194 is preferably movable
between a reduced cross-sectional profile for transluminal
advancement into the left atrial appendage, and an enlarged
cross-sectional orientation as illustrated to fill or to
substantially fill a cross-section through the LAA. The stabilizing
member may enlarge to a greater cross section than the anatomical
cavity, to ensure a tight fit and minimize the likelihood of
compression. One convenient construction includes a plurality of
elements 196 which are radially outwardly expandable in response to
axial compression of a distal hub 191 towards a proximal hub 16.
Elements 196 each comprise a distal segment 198 and a proximal
segment 202 connected by a bend 200. The elements 196 may be
provided with a bias in the direction of the radially enlarged
orientation as illustrated in FIG. 25, or may be radially expanded
by applying an expansion force such as an axially compressive force
between distal hub 191 and proximal hub 16 or a radial expansion
force such as might be applied by an inflatable balloon. Elements
196 may conveniently be formed by laser cutting the same tube stock
as utilized to construct the distal hub 191, proximal hub 16 and
frame 14, as will be apparent to those of skill in the art in view
of the disclosure herein. Alternatively, the various components of
the occlusion device 10 may be separately fabricated or fabricated
in subassemblies and secured together during manufacturing.
[0091] As a post implantation step for any of the occlusion devices
disclosed herein, a radiopaque dye or other visualizable media may
be introduced on one side or the other of the occlusion device, to
permit visualization of any escaped blood or other fluid past the
occlusion device. For example, in the context of a left atrial
appendage application, the occlusion device may be provided with a
capillary tube or aperture which permit introduction of a
visualizable dye from the deployment catheter through the occlusion
device and into the entrapped space on the distal side of the
occlusion device. Alternatively, dye may be introduced into the
entrapped space distal to the occlusion device such as by advancing
a small gauge needle from the deployment catheter through the
barrier 15 on the occlusion device, to introduce dye.
[0092] A further embodiment of the occlusion device 10 is
illustrated in FIGS. 26-27. The occlusion device 10 comprises an
occlusion member 11 and a stabilizing member 194 as in the previous
embodiment. In the present embodiment, however, each of the distal
segments 198 inclines radially outwardly in the proximal direction
and terminates in a proximal end 204. The proximal end 204 may be
provided with atraumatic configuration, for pressing against, but
not penetrating, the wall of the left atrial appendage or other
tubular body structure. Three or more distal segments 198 are
preferably provided, and generally anywhere within the range of
from about 6 to about 20 distal segments 198 may be used. In one
embodiment, 9 distal segments 198 are provided. In this embodiment,
3 of the distal segments 198 have an axial length of about 5 mm,
and 6 of the distal segments 198 have an axial length of about 1
cm. Staggering the lengths of the proximal segments 198 may axially
elongate the zone in the left atrial appendage against which the
proximal ends 204 provide anchoring support for the occlusion
device.
[0093] The occlusion device 10 illustrated in FIGS. 26 and 27 is
additionally provided with a hinge 206 to allow the longitudinal
axis of the occlusion member 11 to be angularly oriented with
respect to the longitudinal axis of the stabilizing member 194. In
the illustrated embodiment, the hinge 206 is a helical coil,
although any of a variety of hinge structures can be utilized. The
illustrated embodiment may be conveniently formed by laser cutting
a helical slot through a section of the tube from which the
principal structural components of the occlusion device 10 are
formed. At the distal end of the hinge 206, an annular band 208
connects the hinge 206 to a plurality of axially extending struts
210. In the illustrated embodiment 210, three axial struts 210 are
provided, spaced equilaterally around the circumference of the
body. Axial struts 210 may be formed from a portion of the wall of
the original tube stock, which portion is left in its original
axial orientation following formation of the distal segments 198
such as by laser cutting from the tubular wall.
[0094] The occlusion member 11 is provided with a proximal zone 212
on each of the spokes 17. Proximal zone 212 has an enhanced degree
of flexibility, to accommodate the fit between the occlusion member
11 and the wall of the left atrial appendage. Proximal section 212
may be formed by reducing the cross sectional area of each of the
spokes 17, or by increasing the length of each spoke by making a
wave pattern as illustrated.
[0095] Each of the spokes 17 terminates in a proximal point 214.
Proximal point 214 may be contained within layers of the barrier
15, or may extend through or beyond the barrier 15 such as to
engage adjacent tissue and assist in retaining the occlusion device
10 at the deployment site.
[0096] Referring to FIGS. 28 and 29, a further variation on the
occlusion device 10 illustrated in FIGS. 24 and 25 is provided. The
occlusion device 10 is provided with a proximal face 216 on the
occlusion member 11, instead of the open and proximally concave
face on the embodiment of FIGS. 24 and 25. The proximal face 216 is
formed by providing a proximal spoke 218 which connects at an apex
220 to each distal spoke 17. Proximal spokes 218 are each attached
to a hub 222 at the proximal end 192 of the occlusion device 10.
The barrier 15 may surround either the proximal face or the distal
face or both on the occlusion member 11. In general, provision of a
proximal spoke 218 connected by an apex 220 to a distal spoke 17
provides a greater radial force than a distal spoke 17 alone, which
will provide an increased resistance to compression if the
occlusion member 11 is positioned with the LAA.
[0097] Referring to FIGS. 30-35, an alternate embodiment of the
occlusion device in accordance with the present invention is
illustrated. In general, the occlusion device 10 comprises an
occluding member but does not include a distinct stabilizing member
as has been illustrated in connection with previous embodiments.
Any of the embodiments previously disclosed herein may also be
constructed using the occluding member only, and omitting the
stabilizing member as will be apparent to those of skill in the art
in view of the disclosure herein.
[0098] The occluding device 10 comprises a proximal end 192, a
distal end 190, and a longitudinal axis extending therebetween. A
plurality of supports 228 extend between a proximal hub 222 and a
distal hub 191. At least two or three supports 228 are provided,
and preferably at least about six. In one embodiment, eight
supports 228 are provided. However, the precise number of supports
228 can be modified, depending upon the desired physical properties
of the occlusion device 10 as will be apparent to those of skill in
the art in view of the disclosure herein, without departing from
the present invention.
[0099] Each support 228 comprises a proximal spoke portion 218, a
distal spoke portion 217, and an apex 220 as has been discussed.
However, each of the proximal spoke 218, distal spoke 17 and apex
220 may be a region on an integral support 228, such as a
continuous rib or frame member which extends in a generally curved
configuration as illustrated with a concavity facing towards the
longitudinal axis of the occlusion device 10. Thus, no distinct
point or hinge at apex 220 is necessarily provided as is disclosed
in previous embodiments, which include a hinged connection between
proximal spoke 218 and distal spoke 17.
[0100] At least some of the supports 228, and, preferably, each
support 228, is provided with one or two or more barbs 195. In the
illustrated configuration, the occlusion device 10 is in its
enlarged orientation, such as for occluding a left atrial appendage
or other body cavity or lumen. In this orientation, each of the
barbs 195 projects generally radially outwardly from the
longitudinal axis, and are inclined in the proximal direction. In
an embodiment where the barbs 195 and corresponding support 228 are
cut from a single ribbon, sheet or tube stock, the barb 195 will
incline radially outwardly at approximately a tangent to the curve
formed by the support 228.
[0101] The occlusion device 10 illustrated in FIG. 30 may be
constructed in any of a variety of ways, as will become apparent to
those of skill in the art in view of the disclosure herein. In one
preferred method, the occlusion device 10 is constructed by laser
cutting a piece of tube stock to provide a plurality of axially
extending slots in-between adjacent supports 228. Similarly, each
barb 195 can be laser cut from the corresponding support 228 or
space in-between adjacent supports 228. The generally axially
extending slots which separate adjacent supports 228 end a
sufficient distance from each of the proximal end 192 and distal
end 190 to leave a proximal hub 222 and a distal hub 191 to which
each of the supports 228 will attach. In this manner, an integral
cage structure may be formed. Alternatively, each of the components
of the cage structure may be separately formed and attached
together such as through soldering, heat bonding, adhesives, and
other fastening techniques which are known in the art. A further
method of manufacturing the occlusion device 10 is to laser cut a
slot pattern on a flat sheet of appropriate material, such as a
flexible metal or polymer, as has been discussed in connection with
previous embodiments. The flat sheet may thereafter be rolled about
an axis and opposing edges bonded together to form a tubular
structure.
[0102] The apex portion 220 which carries the barb 195 may be
advanced from a low profile orientation in which each of the
supports 228 extend generally parallel to the longitudinal axis, to
an implanted orientation as illustrated, in which the apex 220 and
the barb 195 are positioned radially outwardly from the
longitudinal axis. The support 228 may be biased towards the
enlarged orientation, or may be advanced to the enlarged
orientation following positioning within the tubular anatomical
structure, in any of a variety of manners. For example, referring
to FIG. 32, an inflatable balloon 230 is positioned within the
occlusion device 10. Inflatable balloon 230 is connected by way of
a removable coupling 232 to an inflation catheter 234. Inflation
catheter 234 is provided with an inflation lumen for providing
communication between an inflation media source 236 outside of the
patient and the balloon 230. Following positioning within the
target body lumen, the balloon 230 is inflated, thereby engaging
barbs 195 with the surrounding tissue. The inflation catheter 234
is thereafter removed, by decoupling the removable coupling 232,
and the inflation catheter 234 is thereafter removed.
[0103] In an alternate embodiment, the supports 228 are radially
enlarged such as through the use of a deployment catheter 238.
Deployment catheter 238 comprises a lumen for movably receiving a
deployment line 240. Deployment line 240 extends in a loop 244
formed by a slip knot 242. As will be apparent from FIG. 33,
proximal retraction on the deployment line 240 will cause the
distal hub 191 to be drawn towards the proximal hub 222, thereby
radially enlarging the cross-sectional area of the occlusion device
10. Depending upon the material utilized for the occlusion device
10, the supports 228 will retain the radially enlarged orientation
by elastic deformation, or may be retained in the enlarged
orientation such as by securing the slip knot 242 immovably to the
deployment line 240 at the fully radially enlarged orientation.
This may be accomplished in any of a variety of ways, using
additional knots, clips, adhesives, or other techniques known in
the art.
[0104] Referring to FIGS. 34A and 34B, the occlusion device 10 may
be provided with a barrier 15 such as a mesh or fabric as has been
previously discussed. Barrier 15 may be provided on only one
hemisphere such as proximal face 216, or may be carried by the
entire occlusion device 10 from proximal end 192 to distal end 190.
The barrier may be secured to the radially inwardly facing surface
of the supports 228, as illustrated in FIG. 34B, or may be provided
on the radially outwardly facing surfaces of supports 228, or
both.
[0105] A further embodiment of the occlusion device 10 is
illustrated in FIG. 35, in which the apex 220 is elongated in an
axial direction to provide additional contact area between the
occlusion device 10 and the wall of the tubular structure. In this
embodiment, one or two or three or more anchors 195 may be provided
on each support 228, depending upon the desired clinical
performance. The occlusion device 10 illustrated in FIG. 35 may
also be provided with any of a variety of other features discussed
herein, such as a partial or complete barrier 15 covering. In
addition, the occlusion device 10 illustrated in FIG. 35 may be
enlarged using any of the techniques disclosed elsewhere
herein.
[0106] While particular forms of the invention have been described,
it will be apparent that various modifications can be made without
departing from the spirit and scope of the invention. Accordingly,
it is not intended that the invention be limited, except as by the
appended claims.
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