U.S. patent application number 14/079193 was filed with the patent office on 2014-03-20 for method and apparatus for delivering an implant without bias to a left atrial appendage.
The applicant listed for this patent is ATRITECH, INC.. Invention is credited to Kevin Anderson, Kevin Cowden, Chris Quinn, Brian Watschke, Steve Zaver.
Application Number | 20140081314 14/079193 |
Document ID | / |
Family ID | 38140411 |
Filed Date | 2014-03-20 |
United States Patent
Application |
20140081314 |
Kind Code |
A1 |
Zaver; Steve ; et
al. |
March 20, 2014 |
METHOD AND APPARATUS FOR DELIVERING AN IMPLANT WITHOUT BIAS TO A
LEFT ATRIAL APPENDAGE
Abstract
An implant delivery system, comprising: an implantable device
comprising a plurality of supports extending between a proximal end
and a distal end, the supports being moveable between a collapsed
configuration and an expanded configuration, a proximal guide tube
at the proximal end of the supports extending toward the distal
end, and a distal guide tube at the distal end of the supports
extending toward the proximal end, wherein the proximal and distal
guide tubes are telescoping and become further engaged as the
supports move from the collapsed to the expanded configuration.
Inventors: |
Zaver; Steve; (Plymouth,
MN) ; Anderson; Kevin; (Brooklyn Center, MN) ;
Cowden; Kevin; (Maple Grove, MN) ; Quinn; Chris;
(Minneapolis, MN) ; Watschke; Brian; (Eden
Prairie, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ATRITECH, INC. |
PLYMOUTH |
MN |
US |
|
|
Family ID: |
38140411 |
Appl. No.: |
14/079193 |
Filed: |
November 13, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13436700 |
Mar 30, 2012 |
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14079193 |
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|
11607253 |
Dec 1, 2006 |
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13436700 |
|
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60741111 |
Dec 1, 2005 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61B 2017/00579
20130101; A61B 2017/00623 20130101; A61B 2017/00986 20130101; A61B
2017/0412 20130101; A61B 2017/22038 20130101; A61B 17/12022
20130101; A61F 2/011 20200501; A61B 17/12172 20130101; A61B
2017/00597 20130101; A61B 2017/12054 20130101; A61B 2017/0464
20130101; A61B 2017/12095 20130101; A61B 17/0057 20130101; A61B
2017/00619 20130101; A61B 2017/1205 20130101; A61B 17/12122
20130101; A61B 2017/00477 20130101; A61B 2017/00592 20130101; A61F
2/01 20130101; A61B 2017/00632 20130101; A61B 2017/0427 20130101;
A61B 2017/00575 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61B 17/12 20060101
A61B017/12 |
Claims
1. An implant delivery system, comprising: an implantable device
comprising a plurality of supports extending between a proximal end
and a distal end, the supports being moveable between a collapsed
configuration and an expanded configuration; a proximal guide tube
at the proximal end of the supports extending toward the distal
end; and a distal guide tube at the distal end of the supports
extending toward the proximal end; wherein the proximal and distal
guide tubes are telescoping and become further engaged as the
supports move from the collapsed to the expanded configuration.
Description
CROSS-REFERENCE TO RELATED U.S. APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No.
13/436,700, filed Mar. 30, 2012, which is a continuation of U.S.
Ser. No. 11/607,253, filed Dec. 1, 2006, now abandoned, which
claims the benefit of priority from U.S. Provisional No.
60/741,111, filed Dec. 1, 2005, which is incorporated by reference,
herein.
BACKGROUND
[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 hemorrhagic, 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 atrial
fibrillation. 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] During surgical procedures, such as mitral valve repair,
thrombus in the left atrial appendage may leave the LAA and enter
the blood stream of a patient. The thrombus in the blood stream of
the patient can cause embolic stroke. There are known techniques
for closing off the LAA so that thrombus cannot enter the patient's
blood stream. For example, surgeons have used staples or sutures to
close the orifice of the LAA, such that the closed off LAA
surrounds the thrombus. Unfortunately, using staples or sutures to
close off the LAA may not completely close the orifice of the LAA.
Thus, thrombus may leave the LAA and enter the patient's blood
stream, even though the LAA is closed with staples or sutures.
Additionally, closing the orifice of the LAA by using staples or
sutures may result in discontinuities, such as folds or creases, in
the endocardial surface facing the left atrium. Unfortunately,
blood clots may form in these discontinuities and can enter the
patient's blood stream, thereby causing health problems. Moreover,
it is difficult to place sutures at the orifice of the LAA and may
result in a residual appendage. For example, an epicardial approach
to ligate sutures can result in a residual appendage. Similarly,
thrombus may form in the residual appendage and enter the patient's
blood stream causing health problems.
[0007] 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. Various implantable devices and methods of delivery have
been previously described. However, some delivery devices can have
limited flexibility and can provide off-axis loading that creates
moment arms and bending bias. Moment arms and bending bias can
cause the implant to "jump" or move within the left atrial
appendage when it is detached from the implant delivery system.
Therefore, it would be advantageous for a left atrial appendage
implantation to system to avoid moment arms and bending bias such
that when the implant is released it remains in the position it had
when coupled to the delivery system.
SUMMARY OF THE INVENTION
[0008] There is provided in accordance with one embodiment of the
present invention a system and method for minimizing, reducing,
substantially eliminating, and/or eliminating implantation bias
during delivery of an implant. The system includes an implant with
a distal guide tube, an actuation shaft, and a concentrically
attachable disconnect mount. In one embodiment the implant is
configured to contain emboli with a left atrial appendage of a
heart of a patient. The implantable device has a proximal and
distal end with a plurality of supports and is moveable between a
collapsed and an expanded configuration. The distal guide tube at
the distal end of the supports extends toward the proximal end of
the implant. The actuation shaft extends through the proximal end
of the implantable device and is removeably engageable with the
distal guide tube. The disconnect mount is releasably engageable
with the proximal end of the implant and is concentrically
attachable to the proximal end of the implant. In one embodiment,
the implant is self-expandable. In another embodiment, the implant
is collapsed by engaging the actuation shaft with the distal guide
tube while applying a relatively proximal force to the proximal end
of the implant with the disconnect mount.
[0009] In one embodiment of the present invention, an implant
delivery system includes an implantable device, a proximal guide
tube, and a distal guide tube. The implantable device has a
plurality of supports extending between a proximal end and a distal
end. The supports are moveable between a collapsed configuration
and an expanded configuration.
[0010] In one embodiment, the proximal guide tube is located at the
proximal end of the supports and extends toward the distal end of
the device. The distal guide tube is located at the distal end of
the supports and extends toward the proximal end of the device. The
proximal and distal guide tubes are telescoping and become further
engaged as the supports move from the collapsed to the expanded
configuration.
[0011] In another embodiment of the present invention, an implant
delivery system includes an implantable device, an actuation shaft,
and a disconnect mount. In some embodiments, the implant delivery
system further comprises a distal guide tube. The implantable
device has a proximal end, a distal end, and a plurality of
supports extending therebetween. The implantable device is moveable
between a collapsed configuration and an expanded
configuration.
[0012] In one embodiment, the distal guide tube, when provided, is
located at the distal end of the supports and extends toward the
proximal end of the device. The actuation shaft is extendable
through the proximal end of the implantable device and is
removeably engageable with the distal guide tube. The disconnect
mount is releasably engageable with the proximal end of the
implantable device. The disconnect mount is concentrically
attachable to the proximal end of the implantable device.
[0013] In some embodiments, the implantable device is
self-expanding. In other embodiments, the implantable device is
collapsed by engaging the actuation shaft with the distal guide
tube while applying a relatively proximal force to the proximal end
of the implantable device with the disconnect mount.
[0014] In yet another embodiment of the present invention, a method
of actuating an implantable device with a concentric force includes
providing an implantable device, applying a concentric force, and
applying a distal force. The implantable device has a proximal end,
a distal end, and a plurality of supports extending therebetween.
The implantable device is configured to expand from a
reduced-diameter configuration to an expanded-diameter
configuration. In one embodiment, the concentric force is applied
to the proximal end. In other embodiments, the distal force is
applied to the distal end.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a view of a heart and its left atrial
appendage;
[0016] FIG. 2 is a block diagram representing a simplified implant
delivery system in accordance with one embodiment of the present
invention;
[0017] FIG. 2A is a schematic view of one embodiment of the
delivery system of FIG. 2;
[0018] FIG. 3A is a side elevational view of the distal end of an
embodiment of an implant delivery system;
[0019] FIG. 3B is a side elevational view of the distal end of
another embodiment of an implant delivery system;
[0020] FIG. 4A is a side elevational view of the distal end of the
implant delivery system shown in FIG. 3A with a radially-reduced
implant;
[0021] FIG. 4B is a side elevational view of the distal end of the
implant delivery system shown in FIG. 4A with a radially-expanded
implant;
[0022] FIG. 4C is a side elevational view of the distal end of an
implant delivery system shown in FIG. 4B with a released
radially-expanded implant;
[0023] FIG. 5A is a side elevational view of the distal end of the
implant delivery system shown in FIG. 3B with a radially-reduced
implant;
[0024] FIG. 5B is a side elevational view of the distal end of the
implant delivery system shown in FIG. 5A with a radially-expanded
implant;
[0025] FIG. 5C is a side elevational view of the distal end of an
implant delivery system shown in FIG. 5B with a released
radially-expanded implant;
[0026] FIG. 6 is a schematic view of a deployment system delivering
an implantable containment device to the left atrial appendage;
[0027] FIG. 7 is a perspective view of a support structure for a
containment device in accordance with a further embodiment of the
present invention;
[0028] FIG. 7A is a side elevational view of the device of FIG.
7;
[0029] FIG. 7B is an end view taken along the line 7B-7B of FIG.
7A;
[0030] FIGS. 8 and 9 are side elevational schematic representations
of partial and complete barrier layers of the containment device of
FIG. 7;
[0031] FIG. 10 is a side elevational schematic view of an alternate
containment device in accordance with another embodiment of the
present invention;
[0032] FIG. 11 is a schematic view of a deployment system in
accordance with one embodiment of the present invention;
[0033] FIG. 11A is an enlarged detail view of the deployment system
of FIG. 11, showing a releasable lock in an engaged
configuration;
[0034] FIG. 11B is an enlarged detail view as in FIG. 11A, with a
core axially retracted to release the implant;
[0035] FIG. 12A is a perspective view of a flexible guide tube for
use in the configurations of FIG. 11 and/or FIG. 14;
[0036] FIG. 12B is a schematic view of a flexible guide tube for
use in embodiments of the configurations of FIG. 11;
[0037] FIG. 13A is a schematic view of an implant with concentric
slideable guide tubes in a radially-reduced state in accordance
with one embodiment of the present invention;
[0038] FIG. 13B is a schematic view of the implant with concentric
slideable guide tubes of FIG. 13A in a radially-expanded state;
[0039] FIG. 14 is a schematic view of an alternate deployment
system in accordance with one embodiment of the present
invention;
[0040] FIG. 15A illustrates a schematic cross-sectional view
through the distal end of a retrieval catheter having a containment
device removably connected thereto in accordance with one
embodiment of the present invention;
[0041] FIG. 15B is a perspective view of an embodiment of a single
layer petal configuration of a portion of a retrieval catheter in
accordance with one embodiment of the present invention;
[0042] FIG. 15C is a schematic cross-sectional view of the system
illustrated in FIG. 15A, with the containment device axially
elongated and radially reduced;
[0043] FIG. 15D is a cross-sectional schematic view as in FIG. 15C,
with the containment device drawn part way into the retrieval
catheter;
[0044] FIG. 15E is a schematic view as in FIG. 15D, with the
containment device and delivery catheter drawn into a transseptal
sheath;
[0045] FIG. 16A is a schematic cross-sectional view of a distal
portion of an adjustable implant deployment system, in accordance
with another embodiment;
[0046] FIG. 16B is a schematic partial sectional view of an
assembly incorporating quick-disconnect functionality of the
assembly in FIG. 16A;
[0047] FIGS. 17A-C are schematic cross-sectional views of an
implant release and recapture mechanism having an internal lock
tube, in accordance with another embodiment;
[0048] FIGS. 18A-C are schematic cross-sectional views of another
implant release and recapture mechanism having an internal lock
tube, in accordance with another embodiment;
[0049] FIGS. 19A-C are schematic cross-sectional views of an
implant release and recapture mechanism of an implant deployment
system having an external lock tube, in accordance with another
embodiment;
[0050] FIGS. 20A-C are schematic cross-sectional views of another
implant release and recapture mechanism having an external lock
tube, in accordance with another embodiment;
[0051] FIGS. 21A-C are schematic cross-sectional views of an
embodiment of an implant release and recapture mechanism having a
threaded portion of an implant actuation shaft, in accordance with
another embodiment;
[0052] FIGS. 21D-E are cross-sectional views of another embodiment
of an implant release mechanism;
[0053] FIG. 21F is a cross-section view of another embodiment of an
implant release mechanism;
[0054] FIG. 22 is a schematic view of a delivery system in
accordance with one embodiment of the present invention;
[0055] FIG. 22A is a cross-sectional view of an implant delivery
system as shown in FIG. 22, taken along line 22A-22A;
[0056] FIG. 23 is a partial cross-sectional view of the distal end
of a deployment system constructed in accordance with one
embodiment of the present invention;
[0057] FIG. 24 is a partial cross-sectional view of an axially
moveable core used in the system of FIG. 22;
[0058] FIG. 24A is a cross-sectional view of the axially moveable
core of FIG. 24 taken along line 24A-24A;
[0059] FIG. 25 is a schematic of an embodiment of a flexible
catheter system constructed in accordance with one embodiment of
the present invention;
[0060] FIG. 25A is a close up of an embodiment of a puzzle lock
profile constructed in accordance with one embodiment of the
present invention;
[0061] FIG. 25B is a perspective view of a tube with the puzzle
lock profile of FIG. 25A; and
[0062] FIG. 25C is a close up of the puzzle lock profile of FIG.
25B.
DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS
[0063] FIG. 1 illustrates a sectional view of a heart 5 and its
left atrial appendage (LAA) 10. An implant 100 is provided at least
partially within the LAA 10. The terms "implant", "occlusion
device" or "containment device" are broad terms intended to have
their ordinary meaning. In addition, these terms are intended to
refer to devices that are inserted into the body. Such devices may
include a membrane, barrier and/or cover, or may omit these
portions. Embodiments of the invention may also be used to treat
other bodily openings, lumen and cavities, besides the LAA 10. For
example, in some embodiments, the methods, devices and systems
described herein are used to treat any heart opening or defect,
such as a patent foramen ovale (PFO), an atrial septal defect
(ASD), a ventricular septal defect (VSD), a patent ductus
arteriosus (PDA), an aneurysm and/or an aortico-pulmonary
window.
[0064] In various embodiments, an implant 100 can be delivered in a
number of ways, e.g., using conventional transthoracic surgical,
minimally invasive, or port access approaches. Delivery can be made
or done in conjunction with surgical procedures as well. In one
embodiment, the implant 100 is used in conjunction with various
surgical heart procedures related to the heart (e.g., mitral valve
repair) or surgical procedures in the region surrounding the heart.
The delivery system can be used to locate and deploy the implant
100 in order to prevent the passage of embolic material from the
LAA 10, such that thrombus remains contained in the LAA 10.
Thrombus remains contained in the LAA 100 because the implant 100
inhibits thrombus within the LAA 10 from passing through the
orifice of the LAA 10 and into the patient's blood stream.
Additionally, the deployed implant 100 located in the LAA 10 can
provide a smooth, non-thrombogenic surface facing the left atrium.
In one embodiment, the smooth, non-thrombogenic surface facing the
left atrium will not promote blood clots to form proximate to the
LAA 10. Access to the heart may be provided by surgical procedures
in order to deploy the implant 100 in the LAA 10. That is, the
implant 100 can be deployed as an adjunct to surgical procedures.
Various methods for accessing the LAA 10 and delivering an implant
100 to the LAA 10 are disclosed in U.S. application Ser. No.
11/003,696, filed Dec. 3, 2004, published as U.S. Publication No.
2005-0177182 A1, which is incorporated by reference herein.
[0065] A. Implant Delivery System
[0066] FIG. 2 illustrates a block diagram of an implant delivery
system 50. The implant delivery system 50 includes an implant 100,
an implant release and recapture mechanism 200, a catheter system
300 and a deployment handle 400. In some embodiments, the implant
release and recapture mechanism 200 is the distal portion of the
catheter system 300 and the deployment handle 400 is the proximal
portion of the catheter system 300. The implant release and
recapture mechanism 200 generally couples the implant 100 to the
catheter system 300. The deployment handle 400 generally provides
all the user controls and actuators of the implant delivery system
50.
[0067] FIG. 2A illustrates one embodiment of the implant delivery
system 50 of FIG. 2. The implant delivery system 50 includes an
implant release and recapture mechanism 200 that is flexible and
without bias. In this manner, when the implant 100 is released from
the delivery system 50, the implant 100 maintains the position and
orientation it had when coupled to the delivery system 50, and does
not spring, jump, or move, as described above.
[0068] FIG. 3A illustrates one example of an implant 100
(schematically shown) coupled to a catheter system 300 with an
implant release and recapture mechanism 200. In the illustrated
embodiment, the implant release and recapture mechanism 200 is
relatively stiff and extends over a release mechanism length 201.
The implant release and recapture mechanism 200 includes an implant
actuation shaft 334 and a tether line 210. The implant 100 is
generally self-expandable and is held in a reduced-diameter
configuration by pushing against the distal end of the inside of
the implant 100 while pulling on the implant's proximal end. For
example, the implant actuation shaft 334 pushes against the implant
distal end while the tether line 210 is held in tension to maintain
the implant 100 in a reduced-diameter configuration. To expand the
implant, tension on the tether line 210 is reduced and/or the
implant actuation shaft 334 is moved proximally.
[0069] However, the implant actuation shaft 334 and tether line 210
can have limited flexibility and can provide off-axis loading that
creates moment arms and bending bias. Deployment of the implant 100
in the confines of the heart 5 (not illustrated here) may require
bending of the implant release and recapture mechanism 200, a
catheter system 300, but stiffness along a release mechanism length
201 reduces flexibility and creates moment arm and bending
bias.
[0070] FIG. 3B illustrates another embodiment of an implant 100
coupled to a catheter system 300 with an implant release and
recapture mechanism 200. In the illustrated embodiment, the implant
release and recapture mechanism 200 is relatively stiff and extends
over a release mechanism length 202. The implant release and
recapture mechanism 200 and the catheter system 300 are flexible
and can be manipulated in order to access the LAA 10. When device
stiffness or rigidity along a release mechanism length 202 is
shorter than a release mechanism length 201, the device has
increased flexibility and shorter moment arms, resulting in less
bending bias.
[0071] FIGS. 4A-C illustrate the implant release sequence of the
implant 100 with the implant release and recapture mechanism 200 of
FIG. 3A. FIG. 4A illustrates an example of an implant 100, an
implant release and recapture mechanism 200, and a catheter system
300 where the implant release and recapture mechanism 200 is
relatively stiff and extends over a release mechanism length 201.
FIG. 4B illustrates a catheter system 300 using an implant
actuation shaft 334 and a tether line 210, which are used as
components within the implant release and recapture mechanism 200.
When the implant 100 is radially expanded the implant 100 can move
axially toward the distal end of the implant 100, thereby exposing
the implant actuation shaft 334 and tether line 210. The off-axis
tension in the tether line 210 can create moment arms and bending
bias which can cause the implant 100 to "jump," move, rotate, etc.,
within the LAA 10 when the implant 100 is detached from the implant
delivery system, as is illustrated in FIG. 4C.
[0072] FIGS. 5A-C illustrate the implant release sequence of the
implant 100 with the implant release and recapture mechanism 200 of
FIG. 3B. FIG. 5A illustrates an example of an implant 100, an
implant release and recapture mechanism 200, a catheter system 300
where the implant release and recapture mechanism 200 is relatively
stiff and extends over a release mechanism length 202. Length 202
is shorter than length 201 of FIG. 4A. FIG. 5B illustrates the
expansion of the implant 100 with shorter moment arms and less
bending bias than the systems illustrated in FIGS. 4A-C. As
illustrated in FIG. 5C, the release of the implant 100 from the
catheter system 300 results in smaller moment arms and less bending
bias than in FIGS. 4A-C. The detachment of the implant 100 results
in less of a "jump" and reduced movement and/or rotation within the
LAA 10.
[0073] 1. Implant
[0074] FIG. 6 illustrates an implant 100 placed inside a LAA 10 of
a heart 5, an implant release and recapture mechanism 200, and a
catheter system 300. In one embodiment, the implant 100 is a
transluminally delivered device designed to occlude or contain
particles within the LAA 10 and prevent thrombus from forming in,
and emboli from originating from, the LAA 10. The delivery system
50 may be used to deliver the implant 100 to occlude or block the
LAA 10 in a patient with atrial fibrillation. The delivery system
50 may be compatible for use with a transseptal sheath (not shown).
The delivery system 50 and implant 100 may be selected to allow the
implant 100 to be positioned, repositioned, and retrieved from the
LAA 10 if necessary.
[0075] The implant 100 often includes a frame 101 and a membrane
(not shown) on a proximal face 104 of the implant, such as
described below. In an embodiment, the frame 101 is constructed of
self-expanding nitinol supports. The membrane may be constructed of
a fabric covering, such as one made of ePTFE, or an ePTFE/PE
laminate. To attach the membrane to the frame 101, a PE mesh
preferably is placed against the supports, with one sheet of ePTFE
preferably placed over the PE mesh and another sheet of ePTFE
preferably placed on an opposite side of the supports. The membrane
may be heated on both sides causing the PE to melt into both sheets
of ePTFE, thereby surrounding a portion of the frame 101. The
nitinol supports allow the implant 100 to self-expand in the
appendage 10, covering the orifice with the laminated fabric. The
porous ePTFE/PE lamination facilitates rapid endothelialization and
healing.
[0076] In one embodiment, the implant 100 is expandable and
collapsible. The implant 100 can include anchors that extend from
the implant's frame 101 when the implant 100 is expanded, as
described below. The implant 100 is available in a range of sizes
to accommodate the anatomy of a patient's LAA 10. When used in the
LAA 10, the implant 100 may have an expanded diameter within the
range of from about 1 cm to about 5 cm, and, in one embodiment,
about 3 cm. The overall axial length of the implant 10 from its
distal end 102 to its proximal end 104 is within the range of from
about 1.5 cm to about 4 cm and, in one embodiment, about 2.5
cm.
[0077] In one embodiment, the delivery system 50 includes a
transseptal, sheath 520. A radiopaque marker 521 is located near
the distal end of the transseptal sheath 520.
[0078] FIGS. 7, 7A and 7B illustrate an implant 100 in accordance
with another embodiment of the present invention. The implant 100
includes a distal end 102, a proximal end 104; and a longitudinal
axis extending therebetween. A plurality of supports 106 extend
between a distal hub 108 and a proximal hub 110. At least two or
three supports 106 are provided, and in other embodiments, at least
about ten supports 106 are provided. In one embodiment, sixteen
supports 106 are provided. However, the precise number of supports
106 can be modified, depending upon the desired physical properties
of the implant 100 as will be apparent to those of skill in the art
in view of the disclosure herein, without departing from the
present invention.
[0079] In an embodiment, each support 106 includes a distal spoke
portion 112, a proximal spoke portion 114, and an apex 116. Each of
the distal spoke portion 112, the proximal spoke portion 114, and
the apex 116 may be a region on an integral support 106, 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 implant 100. Thus, no distinct point or
hinge at apex 116 is necessarily provided.
[0080] At least some of the supports 106, and, preferably, each
support 106, is provided with one or two or more anchors 118 or
barbs 118. In the illustrated configuration, the implant 100 is in
its enlarged orientation, such as for occluding a left atrial
appendage 10 or other body cavity or lumen. In, this orientation,
each of the barbs 118 projects generally radially outwardly from
the longitudinal axis, and is inclined in the proximal direction.
One or more barbs may also be inclined distally, as is discussed
elsewhere herein. In an embodiment where the barbs 118 and
corresponding support 106 are cut from a single ribbon, sheet or
tube stock, the barb 118 will incline radially outwardly at
approximately a tangent to the curve formed by the support 106.
[0081] The illustrated anchor 118 is in the form of a barb, with at
least one on each support 106 for extending into tissue at or near
the opening of the LAA 10. Depending upon the embodiment, two or
three barbs 118 may alternatively be desired on each support 106.
In the single barb 118 embodiment of FIG. 7, each barb 118 is
inclined in a proximal direction. This is to inhibit proximal
migration of the implant out of the left atrial appendage 10. In
this context, distal refers to the direction into the left atrial
appendage 10, and proximal refers to the direction from the left
atrial appendage 10 into the heart 5.
[0082] Alternatively, one or more barbs 118 may face distally, to
inhibit distal migration of the implant 100 deeper into the LAA 10.
Thus, the implant 100 may be provided with at least one proximally
facing barb 118 and at least one distally facing barb 118. For
example, in an embodiment of the type illustrated in FIG. 10,
discussed below, a proximal plurality of barbs 118 may be inclined
in a first direction, and a distal plurality of barbs 118 may be
inclined in a second direction, to anchor the implant 100 against
both proximal and distal migration.
[0083] The implant 100 constructed from the frame illustrated in
FIG. 7 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 method, the implant 100 is constructed by
laser cutting a piece of tube stock to provide a plurality of
axially extending slots in-between adjacent supports 106.
Similarly, each barb 118 can be laser cut from the corresponding
support 106 or space in-between adjacent supports 106. The
generally axially extending slots which separate adjacent supports
106 end a sufficient distance from each of the proximal end 104 and
distal end 102 to leave a proximal hub 110 and a distal hub 108 to
which each of the supports 106 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, brazing, heat bonding,
adhesives, and other fastening techniques which are known in the
art.
[0084] A further method of manufacturing the implant 100 is to
laser cut a slot pattern on a flat sheet of appropriate material,
such as a flexible metal or polymer. The supports 106 may 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 a proximal hub 110 or a distal hub 108. The flat sheet may
thereafter be rolled about an axis and opposing edges bonded
together to form a tubular structure.
[0085] The apex portion 116 which carries the barb 118 may be
advanced from a low profile orientation in which each of the
supports 106 extend generally parallel to the longitudinal axis, to
an implanted orientation as illustrated, in which the apex 116 and
the barb 118 are positioned radially outwardly from the
longitudinal axis. The support 106 may be biased towards the
enlarged orientation, or may be advanced to the enlarged
orientation under positive force following positioning within the
tubular anatomical structure, in any of a variety of manners.
[0086] Referring to FIGS. 8 and 9, the implant 100 may be provided
with a bather 120 such as a mesh or fabric. The barrier 120 may
comprise any of a variety of materials which facilitate cellular
in-growth, such as ePTFE. The suitability of alternate materials
for barrier 120 can be determined through routine experimentation
by those of skill in the art. The barrier 120 may be provided on
either one or both axially facing sides of the implant 100. In one
embodiment, the barrier 120 comprises two layers, with one layer on
each side of a cage formed by a plurality of supports 106. The two
layers may be bonded to each other around the supports 106 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. In an
embodiment, the barrier 120 has a thickness of no more than about
0.003'' and a porosity within the range of from about 5 .mu.m to
about 60 .mu.m.
[0087] Barrier 120 may be provided on only one hemisphere, proximal
face 122, or may be carried by the entire implant 100 from proximal
end 104 to distal end 102. The barrier may be secured to the
radially inwardly facing surface of the supports 106, as
illustrated in FIG. 9, or may be provided on the radially outwardly
facing surfaces of supports 106, or both.
[0088] A further embodiment of the implant 100 is illustrated in
FIG. 10, in which the apex 116 is elongated in an axial direction
to provide additional contact area between the implant 100 and the
wall of the tubular structure. In this embodiment, one or two or
three or more anchors 118 may be provided on each support 106,
depending upon the desired clinical performance. The implant 100
illustrated in FIG. 10 may also be provided with any of a variety
of other features discussed herein, such as a partial or complete
barrier 120. In addition, the implant 100 illustrated in FIG. 10
may be enlarged using any of the techniques disclosed elsewhere
herein.
[0089] FIG. 11 illustrates another embodiment of the present
invention. The implant 100 may be in the form of any of those
described previously herein, as modified below. In general, the
implant 100 is movable from a reduced crossing profile to an
enlarged crossing profile. The implant 100 is generally introduced
into the body in its reduced crossing profile, and when positioned
at the desired deployment location, the implant 100 is expanded to
its enlarged crossing profile. When expanded, the implant 100
obstructs or filters the flow of desired particles, emboli, blood,
etc., or performs other functions while positioned therein.
[0090] The implant 100 may be biased in the direction of the
enlarged crossing profile, may be neutrally biased, or may be
biased in the direction of the reduced crossing profile. Any
modifications to the device and deployment system to accommodate
these various aspects of the implant 100 may be readily
accomplished by those of skill in the art in view of the disclosure
herein.
[0091] The implant 100 is a detachable component of an adjustable
implant delivery system 50. The implant deliver system 50 generally
includes a catheter 302 for inserting in implant into a patient's
vasculature, advancing it percutaneously through the vasculature,
positioning it at a desire deployment location, and deploying the
implant 100 at the deployment location, such as within a body
cavity or lumen, as discussed above. The catheter 302 generally
includes an elongate flexible tubular body 306 that extends between
a proximal end 308 and a distal end 310. The catheter body has a
sufficient length and diameter to permit percutaneous entry into
the vascular system and transluminal advancement through the
vascular system to the desired deployment site.
[0092] For example, in an embodiment intended for access at the
femoral vein and deployment within the left atrial appendage 50,
the catheter 302 has a length within the range of from about 50 cm
to about 150 cm, and a diameter of generally no more than about 15
French. Further dimensions and physical characteristics of
catheters for navigation to particular sites within the body are
well understood in the art and will not be further described
herein.
[0093] The tubular body 306 is further provided with a handle 402
generally on the proximal end 308 of the catheter 302. The handle
402 permits manipulation of the various aspects of the implant
delivery system 50, as will be discussed below. Handle 402 may be
manufactured in any of a variety of ways, typically by injection
molding or otherwise forming a handpiece for single-hand operation,
using materials and construction techniques well known in the
medical device arts.
[0094] In the illustrated embodiment, the distal end 102 of the
implant 100 is provided with an implant plug 124. The implant plug
124 may be integral with the distal end 102 of the implant or it
may be a separate, attachable piece. Implant plug 124 provides a
stopping surface 126 for contacting an axially movable core 304 or
other such similar structure as described herein. The core 304
extends axially throughout the length of the catheter body 302, and
is attached at its proximal end to a core control 404 on the handle
402. In some embodiments, the axially movable core is referred to
as a drive shaft or an implant actuation shaft. In one embodiment,
the implant plug 124 comprises an atraumatic tip, such that contact
between the atraumatic tip and the inside surface of the LAA 10
does not cause significant damage to the LAA 10.
[0095] The core 304 may comprise any of a variety of structures
which has sufficient lateral flexibility to permit navigation of
the vascular system, and sufficient axial column strength to enable
reduction of the implant 100 to its reduced crossing profile. Any
of a variety of structures such as hypotube, solid core wire,
"bottomed out" coil spring structures, or combinations thereof may
be used, depending upon the desired performance of the finished
device. In one embodiment, the core 304 comprises stainless steel
tubing.
[0096] The distal end of core 304 is positioned within a recess,
cavity or lumen 132 defined by a proximally extending distal guide
tube 130. In the illustrated embodiment, the distal guide tube 130
is a section of tubing such as metal hypotube, which is attached at
the distal end 102 of the implant and extends proximally within the
implant 100. In some embodiments the distal guide tube 130 includes
a distal end 102 of the implant, an implant plug 124, and/or a
stopping surface 126 as described herein. The distal guide tube 130
preferably extends a sufficient distance in the proximal direction
to inhibit buckling or prolapse of the core 304 when distal
pressure is applied to the core control 404 to reduce the profile
of the implant 100. However, the guide tube 130 should not extend
proximally a sufficient distance to interfere with the opening of
the implant 100.
[0097] As will be appreciated by reference to FIG. 11, the guide
tube 130 may operate as a limit on distal axial advancement of the
proximal end 104 of implant 100. Thus, the guide tube 130
preferably does not extend sufficiently far proximally from the
distal end 102 to interfere with optimal opening of the implant
100. The specific dimensions are therefore relative, and will be
optimized to suit a particular intended application. In one
embodiment, the implant 100 has an implanted outside diameter
within the range of from about 5 mm to about 45 mm, and an axial
implanted length within the range of from about 5 mm to about 45
mm. The guide tube 130 has an overall length of about 3 mm to about
35 mm, and an outside diameter of about 0.095 inches. Additional
disclosure relating to this embodiment is discussed below, relating
to FIGS. 11A and 11B.
[0098] An alternate embodiment of a guide tube 130 is schematically
illustrated in FIGS. 12A and 12B. In this configuration, the guide
tube 130 comprises a plurality of tubular segments 134 spaced apart
by at least one intervening space 136. This allows increased
flexibility of the guide tube 130, which may be desirable during
the implantation step, while retaining the ability of the guide
tube 130 to maintain linearity of the core 304 while under axial
pressure. Although three segments 134 are illustrated in FIG. 12A
and four segments are illustrated in FIG. 12B, as many as 10 or 20
or more segments 134 may be desirable depending upon the desired
flexibility of the resulting implant. Each adjacent pair of
segments 134 may be joined by a hinge element 138 which permits
lateral flexibility. In the illustrated embodiment of FIG. 12A, the
hinge element 138 comprises an axially extending strip or spine
138, which provides column strength along a first side of the guide
tube 130. The guide tube 130 may therefore be curved by compressing
a second side of the guide tube 130 which is generally offset from
the spine 138 by about 180.degree. A limit on the amount of
curvature may be set by adjusting the axial length of the space 136
between adjacent segments 134. As illustrated in FIG. 12B, an
embodiment of a guide tube 130 may have each axial spine 138 be
rotationally offset from the next adjacent axial spine 138 to
enable flexibility of the overall guide tube 130 throughout a
360.degree. angular range of motion.
[0099] Alternatively, the flexible hinge point 138 between each
adjacent segment 134 may be provided by cutting a spiral groove or
plurality of parallel grooves in a tubular element in between what
will then become each adjacent pair of segments 134. In this
manner, each tubular element 134 will be separated by an integral
spring like structure, which can permit flexibility. As a further
alternative, the entire length of the guide tube 130 may comprise a
spring. Each of the forgoing embodiments may be readily constructed
by laser cutting or other cutting from a piece of tube stock, to
produce a one piece guide tube 130. Alternatively, the guide tube
130 may be assembled from separate components and fabricated
together using any of a variety of bonding techniques which are
appropriate for the construction material selected for the tube
320.
[0100] Various distal end 102 constructions may be utilized, as
will be apparent to those of skill in the art in view of the
disclosure herein. In the illustrated embodiment, the distal
implant plug 124 extends within the implant 100 and is attached to
the distal end of the guide tube 130. The implant plug 124 may be
secured to the guide tube 130 and implant 100 in any of a variety
of ways, depending upon the various construction materials. For
example, any of a variety of metal bonding techniques such as a
welding, brazing, interference fit such as threaded fit or snap
fit, may be utilized. Alternatively, any of a variety of bonding
techniques for dissimilar materials may be utilized, such as
adhesives, and various molding techniques. In one construction, the
implant plug 124 comprises a molded polyethylene cap, and is held
in place utilizing a distal cross pin 140 which extends through the
implant 100, the guide tube 130 and the implant plug 124 to provide
a secure fit against axial displacement.
[0101] Some left atrial appendage implants, such as some of those
described in some of the embodiments above (for examples, see FIGS.
11-12B) and below (e.g., see FIG. 14-16B), include a single guide
tube 130 at the distal end 102 of the implant 100 that connects to
or engages an implant actuation shaft and provides axial load
transmission from the distal guide tube 130 to the implant 100 at
its distal end 102. In some embodiments, the shaft may be an
implant actuation shaft 334, an axially moveable core 304 or
rotatable core 342.
[0102] When the implant actuation shaft is particularly flexible or
relatively long for actuation of a long implant 100, it could
buckle if not adequately supported within the implant 100. To
prevent bending or buckling of the implant actuation shaft 334,
support preferably is provided only inside the implant 100 in order
to maintain the interface with a catheter system 300 proximal and
adjacent to the implant 100 as flexible as possible. Given the
continuously changing length of the implant 100 depending on its
expansion state, a support member that also changed length with the
implant 100 would be useful as well.
[0103] FIGS. 13A and 13B illustrate an alternate embodiment of an
implant 100, which includes multiple guide tubes 162, 164. The
implant 100 includes two substantially concentric or axially
aligned telescoping guide tubes 162, 164, which are slidably
moveable with respect to one another. The outer guide tube 162 is
attached to the implant's distal end 102 or may be integrally
formed therewith, and the inner guide tube 164 is attached to its
proximal end 104 or may be integrally formed therewith, although in
other embodiments they are attached to proximal and distal ends,
respectively. In a concentric embodiment, the outer guide tube 162
has an internal diameter sufficiently large enough to contain the
outer diameter of the inner guide tube 164. In certain embodiments,
the telescoping guide tubes 162 and 164 perform a support function
when each is anchored at either the distal end 102 or proximal end
104 of the implant 100 and by freely floating at the interface
between telescoping guide tubes 162 and 164.
[0104] The outer guide tube 162 and the inner guide tube 164 are
sized to allow full support of an implant actuation shaft 334
without increasing the collapse force used to reduce the implant's
diameter. The telescoping guide tubes 162 and 164 can be utilized
with embodiments having a disconnect mount 236 (see FIGS. 17-21),
tethered embodiments, or any other embodiments disclosed
herein.
[0105] Referring to FIG. 13A, when the implant 100 is in a radially
reduced state, the inner guide tube 164 overlaps the outer guide
tube 162, as shown. Alternatively, the inner guide tube 164 may not
overlap with the outer guide tube 162 in the radially reduced state
of the implant 100. Referring to FIG. 13B, when the implant 100 is
radially expanded, the inner guide tube 164 slides into the outer
guide tube 162 as the overall length of the implant 100 is axially
shortened. The outer guide tube 162 can have a flared end to
facilitate collapse of the implant 100. A flared end of the outer
guide tube 162 can help guide the inner guide tube 164 during
expansion. Similarly, the inner guide tube 164 can have a tapered
end.
[0106] In some embodiments of an implant 100 with multiple guide
tubes, either of the outer guide tube 162 or the inner guide tube
164 may also be a distal guide tube 130 or a proximal guide tube
160. The outer guide tube 162 can be a distal guide tube 130
attached at its distal end to the distal end 102 of the implant
100, and the inner guide tube 164 can be a proximal guide tube 160
attached at its proximal end to the proximal end 104 of the implant
100. The outer guide tube 162 may include a mating surface on or
near its distal end to engage a mating surface on the distal hub
108, or elsewhere on the implant 100.
[0107] Relative proximal and distal movement of the inner guide
tube 164 and outer guide tube 162 is preferably limited by a motion
limit. In one embodiment, the motion limit includes at least one
cross pin. In other embodiments, the motion limit includes at least
one flare, annular ring, bump, or other suitable mechanism as is
well known to those of skill in the art. The outer guide tube 162
slidably engages the inner guide tube 164, which preferably enters
the proximal end of the outer guide tube 162. One advantage of this
embodiment is a reduction in the likelihood that the insertion of
an implant actuation shaft 334 into the implant 100 will bind on
the proximal end of distal guide tube 130 while assembling a
implant delivery system 50 or while attempting to recapture a
detached implant 100. Alternatively, in another embodiment, the
outer guide tube 162 can be attached at its proximal end to the
proximal end 104 of the implant 100, and the inner guide tube 164
can be attached at its distal end to the distal end 102 of the
implant 100.
[0108] In an embodiment of an implant 100 with multiple guide
tubes, the distal guide tube 130 has a distal guide tube lumen 132
and the proximal guide tube 160 has a proximal guide tube lumen
170. These lumens 132 and 170 may contain radiopaque or contrast
materials injected into the catheter system 300 through ports in
the deployment handle 400. The proximal guide tube 160 may have a
window 170 that passes through the wall of the proximal guide tube
160. The window 170 may be used to release contrast materials in
the proximal guide tube lumen 170 toward the proximal end 104 of
the implant 100. This window 170 may also be used as an anchor
point or port through which a pull wire 312 from a catheter system
300 may be used to secure the implant 100 prior to detachment.
[0109] In certain embodiments of an implant 100 with multiple guide
tubes, a slideable engagement surface 166 of the outer guide tube
162 may interface with a slideable engagement surface 168 of the
inner guide tube 164. Various embodiments of the outer guide tube
162 and inner guide tube 164 may comprise generally circular cross
sections which allow free rotation about the concentric axis of the
guide tubes along the generally coaxial cylindrical slideable
engagement surfaces 166 and 168. Alternatively, other embodiments
may have slideable engagement surfaces 166 and 168 which are
elliptically-shaped or contain certain key and slot configurations
or similar interface configurations known in the art to prevent or
reduce relative rotation between the outer guide tube 162 and inner
guide tube 164. Depending on how the guide tubes are attached to
the ends of the implant 100, these rotation-inhibiting embodiments
may provide additional support to reduce rotation in the frame 101
of the implant 100.
[0110] In some embodiments of the implant actuation shaft 334, the
shaft may be an axially moveable core 304, a rotatable core 342, or
a shaft that uses an unscrew-to-release mechanism similar to an
embodiment as illustrated in FIG. 14 (see below). By using two
telescoping guide tubes 130 and 160, the free detensioned length of
the implant 100 can be doubled.
[0111] Further advantages of multiple guide tube embodiments are
described in the context of an improved implant release and
recapture mechanism.
[0112] 2. Implant Release and Recapture Mechanisms
[0113] Various embodiments of implant release and recapture
mechanisms provide an interface between an implant and a catheter
system used to deploy, detach, and recapture the implant.
[0114] a. Pull Wire Mechanisms
[0115] Referring back to FIG. 11, there is illustrated an
embodiment of an implant delivery system 50 with a detachable
implant 100, an implant release and recapture mechanism 200, a
catheter system 300, and a deployment handle 400. As illustrated in
this embodiment, the implant release and recapture mechanism 200
includes a release element, such as a pull wire 312, which keeps
the proximal end 104 of the implant 100 in tension. An axially
moveable core 304 simultaneously pushes against the distal end 102
of the implant 100. The combination of pulling on the implant
proximal end 104 while pushing on its distal end 102 keeps the
implant 100 in a compressed state. When either the core 304 is
pulled proximally or the pull wire 312 is allowed to move distally,
the tension on the ends of the implant 100 is reduced, thereby
allowing the spring loaded or shape memory material in the implant
100 to radially expand into its normal expanded state.
[0116] In this embodiment, the proximal end 104 of the implant 100
is provided with a releasable lock 142 for attachment to a pull
wire 312. Pull wire 312 extends proximally throughout the length of
the tubular body 306 to a proximal pull wire control 406 on the
handle 402.
[0117] As used herein, the term pull wire is intended to include
any of a wide variety of structures which are capable of
transmitting axial tension or compression such as a pushing or
pulling force with or without rotation from the proximal end 308 to
the distal end 310 of the catheter 302. Thus, monofilament or
multifilament metal or polymeric rods or wires, woven or braided
structures may be utilized. Alternatively, tubular elements such as
a concentric tube positioned within the outer tubular body 306 may
also be used as will be apparent to those of skill in the art.
[0118] In the illustrated embodiment in FIG. 11, the pull wire 312
is releasably connected to the proximal end 104 of the implant 100.
This permits proximal advancement of the proximal end of the
implant 100, which cooperates with a distal retention force
provided by the core 304 against the distal end of the implant to
axially elongate the implant 100 thereby reducing it from its
implanted configuration to its reduced profile for implantation.
The proximal end of the pull wire 312 may be connected to any of a
variety of pull wire controls 406, including rotational knobs,
levers and slider switches, depending upon the design
preference.
[0119] The implant delivery system 50 thus permits the implant 100
to be maintained in a low crossing profile configuration, to enable
transluminal navigation to a deployment site. Following positioning
at or about the desired deployment site, proximal retraction of the
core 304 enables the implant 100 to radially enlarge under its own
bias to fit the surrounding tissue structure. Alternatively, the
implant can be enlarged under positive force, such as by inflation
of a balloon or by a mechanical mechanism. Once the clinician is
satisfied with the position of the implant 100, such as by
injection of dye and visualization using conventional techniques,
the core 304 is proximally retracted thereby releasing the lock 142
and enabling detachment of the implant 100 from the deployment
system 300.
[0120] If, however, visualization reveals that the implant 100 is
not at the location desired by the clinician, proximal retraction
of the pull wire 312 with respect to the core 304 will radially
reduce the diameter of the implant 100, thereby enabling
repositioning of the implant 100 at the desired site. Thus, the
present invention permits the implant 100 to be enlarged or reduced
by the clinician to permit repositioning and/or removal of the
implant 100 as may be desired.
[0121] The proximal end 104 of the implant 100 is preferably
provided with a releasable lock 142 for attachment of the pull wire
312 to the deployment catheter 302. In the illustrated embodiment
in FIG. 11, the releasable lock 142 is formed by advancing the pull
wire 312 distally around a proximal cross pin 146, and providing an
eye or loop which extends around the core 304. As long as the core
304 is in position within the implant 100, proximal retraction of
the pull wire 312 will advance the proximal end 104 of the implant
100 in a proximal direction. See FIG. 11A. However, following
deployment, proximal retraction of the core 304 such as by
manipulation of the core control 404 will pull the distal end of
the core 304 through the loop on the distal end of the pull wire
312. The pull wire 312 may then be freely proximally removed from
the implant 100, thereby enabling detachment of the implant 100
from the delivery system 50 within a treatment site. See FIG.
11B.
[0122] The embodiment illustrated in FIGS. 11, 11A and 11B may
impart bias to the implant 100 because the location of the cross
pin 146 creates a moment arm with respect to the core 304 when
tension is applied to the pull wire 312 in order to maintain the
implant 100 in a radially-reduced configuration. Tension through
the pull wire 312 may be on the order of six pounds of force, which
when loaded off-center by the pull wire 312 over the distance
between the center of the core 304 over the cross pin 146 may
result in significant torque and bias on the implant 100 while it
is being deployed in the LAA 10. This bias may result in deflection
in the delivery system 50 which may cause the implant 100 to jump,
move, rotate, etc., when released from the catheter system 300
during detachment.
[0123] b. Threadable Torque Rod Mechanisms
[0124] FIG. 14 illustrates an alternate embodiment of an implant
deployment system 50 in which an implant 100 is radially enlarged
or reduced by rotating a torque element extending throughout the
deployment catheter. This embodiment of the implant deployment
system 50 reduces the bias of moment arms described in the previous
embodiment by eliminating off-center pull wires 312 (as illustrated
in FIGS. 11, 11A and B). Instead, the elongate flexible tubular
body 306 of the deployment catheter 302 includes a rotatable torque
rod 340 extending axially therethrough. The proximal end of the
torque rod 340 may be connected at a proximal manifold to a manual
rotation device such as a hand crank, thumb wheel, rotatable knob
or the like. Alternatively, the torque rod 340 may be connected to
a power driven source of rotational energy such as a motor drive or
air turbine. The distal end of the torque rod 340 is integral with
or is connected to a rotatable core 342 which extends axially
through the implant 100. A distal end 344 of the rotatable core 342
is positioned within a cavity 132 as has been discussed.
[0125] The terms torque rod or torque element are intended to
include any of a wide variety of structures which are capable of
transmitting a rotational torque throughout the length of a
catheter body. For example, solid core elements such as stainless
steel, nitinol or other nickel titanium alloys, or polymeric
materials may be utilized. In an embodiment intended for
implantation over a guidewire, the torque rod 340 is preferably
provided with an axially extending central guidewire lumen. This
may be accomplished by constructing the torque rod 340 from a
section of hypodermic needle tubing, having an inside diameter of
from about 0.001 inches to about 0.005 inches or more greater than
the outside diameter of the intended guidewire. Tubular torque rods
340 may also be fabricated or constructed utilizing any of a wide
variety of polymeric constructions which include woven or braided
reinforcing layers in the wall. Torque transmitting tubes and their
methods of construction are well understood in the intracranial
access and rotational atherectomy catheter arts, among others, and
are not described in greater detail herein.
[0126] Use of a tubular torque rod 340 also provides a convenient
infusion lumen for injection of contrast media within the implant
100, such as through a port 343 or lumen 350. In one embodiment,
axially moveable core 304 also includes a lumen 350. The lumen 350
preferably allows visualization dye to flow through the lumen 350
of the axially moveable core 304, through the lumen 150 of the
implant end cap 148, and into the left atrial appendage 10. Such
usage of visualization dye is useful for clinical diagnosis and
testing of the position of the implant 100 within the left atrial
appendage 10 or other body opening, as described in greater detail
below.
[0127] The marker 360 as shown in FIG. 14 advantageously assists in
locating the position of the distal end 344 of the axially moveable
core 342. In one embodiment, marker 360 comprises a radiopaque band
press fit onto the distal end 344 of the axially moveable core 342.
Marker 360 preferably is made from a material readily identified
after insertion into a patient's body by using visualization
techniques that are well known to those of skill in the art. In one
embodiment, the marker 360 is made from gold, or tungsten, or any
such suitable material, as is well known to those of skill in the
art. In another embodiment, marker 360 is welded, soldered, or
glued onto the distal end 344 of the axially moveable core 342. In
one embodiment, marker 360 is an annular band and surrounds the
circumference of the axially moveable core 342. In other
embodiments, the marker 360 does not surround the circumference of
the axially moveable core 342. In other embodiments, marker 360
includes evenly or unevenly spaced marker segments. In one
embodiment, the use of marker segments is useful to discern the
radial orientation of the implant 100 within the body.
[0128] The proximal end 104 of the implant 100 is provided with a
threaded aperture 346 through which the core 342 is threadably
engaged. As will be appreciated by those of skill in the art in
view of the disclosure herein, rotation of the threaded core 342 in
a first direction relative to the proximal end 104 of the implant
100 will cause the rotatable core 342 to advance distally. This
distal advancement will result in an axial elongation and radial
reduction of the implantable device 100. Rotation of the rotatable
core 342 in a reverse direction will cause a proximal retraction of
the rotatable core 342, thus enabling a radial enlargement and
axial shortening of the implantable device 100.
[0129] The deployment catheter 302 is further provided with an
anti-rotation lock 348 between a distal end 310 of the tubular body
306 and the proximal end 104 of the implant 100. In general, the
rotational lock 348 may be conveniently provided by cooperation
between a first surface 352 on the distal end 310 of the deployment
catheter 302, which engages a second surface 354 on the proximal
end 104 of the implant 100, to rotationally link the deployment
catheter 302 and the implantable device 100. Any of a variety of
complementary surface structures may be provided, such as an axial
extension on one of the first 352 and second surfaces 354 for
coupling with a corresponding recess on the other of the first 352
and second surfaces 354. Such extensions and recesses may be
positioned laterally offset from the axis of the catheter 302.
Alternatively, they may be provided on the longitudinal axis with
any of a variety of axially releasable anti-rotational couplings
having at least one flat such as a hexagonal or other multifaceted
cross-sectional configuration.
[0130] Upon placement of the implant 100 at the desired
implantation site, the torque rod 340 is rotated in a direction
that produces an axial proximal retraction. This allows radial
enlargement of the radially outwardly biased implant 100 at the
implantation site. Continued rotation of the torque rod 340 will
cause the threaded core 342 to exit proximally through the threaded
aperture 346. At that point, the deployment catheter 302 may be
proximally retracted from the patient, leaving the implanted device
100 in place.
[0131] By modification of the decoupling mechanism to allow the
core 342 to be decoupled from the torque rod 340, the rotatable
core 342 may be left within the implant 100, as may be desired
depending upon the intended deployment mechanism. For example, the
distal end of the core 342 may be rotatably locked within the end
cap 148, such as by including complimentary radially outwardly or
inwardly extending flanges and grooves on the distal end of the
core 342 and inside surface of the cavity 132. In this manner,
proximal retraction of the core 342 by rotation thereof relative to
the implant 100 will pull the end cap 148 in a proximal direction
under positive force. This may be desirable as a supplement to or
instead of a radially enlarging bias built into the implant
100.
[0132] In other embodiments, the torque rod 340 is threaded at its
distal end. The distal end is threaded into a sliding nut located
within a guide tube extending from the distal end of the implant
100. Such embodiments are described in greater detail in U.S.
application Ser. No. 10/642,384, filed Aug. 15, 2003, published as
U.S. Publication No. 2005/0038470, which is expressly incorporated
by reference herein. Another embodiment of an implant deployment
system that could include a torque rod threaded at its distal end
in a manner similar to an embodiment illustrated in FIG. 16A.
[0133] The implant 100 may also be retrieved and removed from the
body in accordance with a further aspect of the present invention.
One manner of retrieval and removal is described with respect to
FIGS. 15A-E. Referring to FIG. 15A, an implanted device 100 is
illustrated as releasably coupled to the distal end of the tubular
body 306, as has been previously discussed. Coupling may be
accomplished by aligning the tubular body 306 with the proximal end
104 of the deployed implant 100, under fluoroscopic visualization,
and distally advancing a rotatable core 342 through the threaded
aperture 346. Threadable engagement between the rotatable core 342
and aperture 346 may thereafter be achieved, and distal advancement
of core 342 will axially elongate and radially reduce the implant
100.
[0134] The tubular body 306 is axially movably positioned within an
outer tubular delivery or retrieval catheter 502. In various
embodiments, the retrieval catheter 502 may be separate and
distinct from the delivery or deployment catheter 302, or the
retrieval catheter 502 may be coaxial with the delivery or
deployment catheter 302, or the retrieval catheter 502 may be the
same catheter as the delivery or deployment catheter 302. Catheter
502 extends from a proximal end (not illustrated) to a distal end
506. The distal end 506 is preferably provided with a flared
opening, such as by constructing a plurality of petals 510 for
facilitating proximal refraction of the implant 100 as will become
apparent.
[0135] Petals 510 may be constructed in a variety of ways, such as
by providing axially extending slits in the distal end 506 of the
catheter 502. In this manner, preferably at least about three, and
generally at least about four or five or six petals or more will be
provided on the distal end 506 of the catheter 502. Petals 510
manufactured in this manner would reside in a first plane,
transverse to the longitudinal axis of the catheter 502, if each of
such petals 510 were inclined at 90 degrees to the longitudinal
axis of the catheter 502.
[0136] In one embodiment, a second layer of petals 512 are
provided, which would lie in a second, adjacent plane if the petals
512 were inclined at 90 degrees to the longitudinal axis of the
catheter 502. Preferably, the second plane of petals 512 is
rotationally offset from the first plane of petals 510, such that
the second petals 512 cover the spaces 514 formed between each
adjacent pair of petals 510. The use of two or more layers of
staggered petals 510 and 512 has been found to be useful in
retrieving implants 100, particularly when the implant 100 carries
a plurality of tissue anchors 118. However, in many embodiments,
the retrieval catheter 502 includes only a single plane of petals
510, such as illustrated in FIG. 15B.
[0137] The petals 510 and 512 may be manufactured from any of a
variety of polymer materials useful in constructing medical device
components such as the catheter 502. This includes, for example,
polyethylene, PET, PEEK, PEBAX, and others well known in the art.
The second petals 512 may be constructed in any of a variety of
ways. In one convenient construction, a section of tubing which
concentrically fits over the catheter 502 is provided with a
plurality of axially extending slots in the same manner as
discussed above. The tubing with a slotted distal end may be
concentrically positioned on the catheter 502, and rotated such
that the space between adjacent petals 512 is offset from the space
between adjacent petals 510. The hub of the petals 512 may
thereafter be bonded to the catheter 502, such as by heat
shrinking, adhesives, or other bonding techniques known in the art.
FIG. 15B shows a perspective view of an embodiment of a single
layer of petals 510 which is coaxial with a transseptal catheter
520 and an implant actuation shaft 334. The implant actuation shaft
334 can be rotatable core 342 as illustrated in FIG. 15A.
[0138] The removal sequence will be further understood by reference
to FIGS. 15C through 15E. Referring to FIG. 15C, the radially
reduced implant 100 is proximally retracted part way into the
retrieval catheter 502. This can be accomplished by proximally
retracting the tubular body 306 and/or distally advancing the
catheter 502. As illustrated in FIG. 15D, the tubular body 306
having the implant 100 attached thereto is proximally retracted a
sufficient distance to position the tissue anchors 118 within the
petals 510. The entire assembly of the tubular body 306, within the
retrieval catheter 502 may then be proximally retracted within the
transseptal sheath 520 or other tubular body as illustrated in FIG.
15E. The collapsed petals 510 allow this to occur while preventing
engagement of the tissue anchors 118 with the distal end of the
transseptal sheath 520 or body tissue. The entire assembly having
the implant 100 contained therein may thereafter be proximally
withdrawn from or repositioned within the patient.
[0139] The embodiments illustrated in FIGS. 14 and 15 may impart
bias to the implant 100 because relative rotation between the
catheter system 300 and the implant 100 is required in order to
release the threaded locking system described above. When the
implant 100 is to be radially expanded within the LAA 10 the torque
rod 342 must be rotated with respect to the threaded aperture 346
in the implant 100. The rotation of the rod with respect to the
implant may result in torque, causing a rotational bias in the
implant 100 with respect to the LAA 10 as well as with respect to
the catheter system 300. This bias may result in deflection in the
delivery system 50 which may cause the implant 100 to "jump" or
"spin" when released from the catheter system 300 during
detachment.
[0140] c. Axial Decoupling Mechanisms
[0141] FIGS. 16A and 16B illustrate another embodiment of an
implant delivery system 50. The system 50 of the illustrated
embodiment provides some axial decoupling between an axially
moveable core 304 and an implant 100. This embodiment of the
implant deployment system 50 reduces the bias of torsion loads
described in the previous embodiment by eliminating rotational
forces related to a threaded engagement between an implant 100 and
a catheter system 300 (as illustrated in FIGS. 14 and 15).
Furthermore, it is clinically advantageous to provide axial
decoupling between the axially moveable core 304 and the implant
100 is because axial decoupling assures that movement of the
axially moveable core 304, as well as other components of the
adjustable implant delivery system 50 that are coupled to the
axially moveable core 304 (for example, but not limited to the
deployment handle 400 and the catheter system 300, described
further herein), do not substantially affect the shape or position
of the implant 100. Such axial decoupling prevents inadvertent
movement of the axially moveable core 304 or deployment handle 400
from affecting the shape or position of implant 100.
[0142] For example, in one embodiment, if the user inadvertently
pulls or pushes the axially moveable core 304 or the deployment
handle 400, the position of the implant 100 within the left atrial
appendage 10 preferably will not be substantially affected. In
addition, axial decoupling also preferably prevents the motion of a
beating heart 5 from translating into movement of the axially
moveable core 304, the catheter 300, and/or the components coupled
to the axially moveable core 304 and catheter 300, including the
deployment handle 400. By decoupling the implant 100 from the
axially moveable core 304 and other components coupled to the
axially moveable core 304, the risk of accidentally dislodging the
implant 100 from the left atrial appendage 10 is reduced.
[0143] The illustrated implant release and recapture mechanism 200
of FIGS. 16A and 16B provides quick-disconnect functionality for
release of axially moveable core 304 from guide tube 130 by using
non-rotational forces. As illustrated, the implant release and
recapture mechanism 200 includes a guide tube 130, which comprises
at least one slot 154. Two opposing slots 154 are shown in the
embodiment of FIGS. 16A and 16B. Axially moveable core 304 is
coupled to guide tube 130 by quick-disconnect functionality.
[0144] Axially moveable core 304 in this embodiment includes a
retractable lock 220 in the form of an elongate key 222 extending
through the lumen of the core 304, and two opposing ports 224 in
axially moveable core 304 through which two tabs 226 extend. The
distal tip 228 of the key 222 includes a contact surface 230
operable to engage contact surfaces 232 of the tabs 226. The key
222 is moveable relative to the axially moveable core 304, and can
be moved distally such that contact surface 230 engages contact
surfaces 232 of tabs 226, translating into radial movement of tabs
226. Radial movement of tabs 226 causes them to project into slots
154 of the guide tube 130 by bending radially outwardly, and
extending in a substantially radial direction. In one embodiment,
the key 222 is secured in place relative to the axially moveable
core 304, so that the tabs 226 remain projected into the slots 154
of the guide tube 130. With the tabs 226 secured in place, axial
movement of axially moveable core 304 preferably is limited by
interference between the tabs 226 and the proximal and distal
surfaces 156, 158 of guide tube 130.
[0145] In one embodiment, the key 222 is made from an elongate
wire, rod, or tube flexible enough for delivery through the
adjustable implant delivery system 50 described above, and strong
enough to apply enough force to tabs 226 to achieve the
functionality described above. In one embodiment, the key 222 is
made from stainless steel. The key 222 preferably is locked in
place relative to the axially moveable core 304 by using a control,
such as a thumbswitch or other such device as is well known to
those of skill in the art. For example, in one embodiment, the
axially moveable core 304 is secured to the proximal portion of a
deployment handle 400 (not shown) such that the position of the
axially moveable core 304 is fixed with respect to the deployment
handle 400. A key 222 preferably is inserted inside of the axially
moveable core 304 such that it may slide axially within the axially
moveable core 304. The proximal portion of the key 222 preferably
is coupled to a control, such as, for example, a thumbswitch. The
thumbswitch preferably is provided such that it may slide axially
with respect to the deployment handle 400 (and therefore with
respect to the axially moveable core 304) over a predetermined
range. By coupling the thumbswitch to the proximal portion of the
key 222, axial movement of the key 222 with respect to the axially
moveable core 304 is achieved over the predetermined range. In
addition, by locking the thumbswitch in place (by using mechanisms
well known to those of skill in the art, such as release buttons,
tabs, or their equivalents), the key 222 may be locked in place
with respect to the axially moveable core 304. Alternatively,
switches, levers, buttons, dials, and similar devices well known to
those of skill in the art may be used instead of a thumbswitch as
the control for the retractable lock 220.
[0146] To decouple axially moveable core 304 from the guide tube
130, retractable lock 220 is released by moving key 222 proximally
relative to axially moveable core 304, thereby removing radial
forces from contact surfaces 232 of tabs 226. In one embodiment,
tabs 226 are biased to bend inward upon the removal of the radial
forces from their contact surfaces 232. For example, tabs 226
preferably are constructed from a spring material, or a shape
memory metal, such as, for example, nickel titanium. Alternatively,
in another embodiment, key 222 is moved distally to decouple
axially moveable core 304 from the guide tube 130. For example, in
one embodiment, key 222 includes a cutout, notch, or slot along at
least a portion of its distal end. In one embodiment, as the key
222 is moved distally, the cutout, notch, or slot is moved such
that it engages the tabs 226, allowing them to flex inwardly
preferably under their own bias. In another embodiment, tabs 226
are biased to bend outward upon removal of a radial force from a
contact surface 232, and bend inward upon application of a radial
force to contact surface 232. In such embodiment, the key 222
preferably is advanced distally to apply force on a contact surface
232 such that tabs 226 are directed inward. In one embodiment, the
key 222 is advanced proximally to apply force on a contact surface
232 such that tabs 226 are directed inward.
[0147] In other embodiments, a guide tube 130 need not be connected
to the implant 100, and for example, can be provided as part of the
axially moveable core 304, or even the deployment handle 402 in
order to decouple axial movement between the implant 100 and the
rest of the delivery system 50. For example, in one embodiment, an
axially moveable core may include two concentric or axially aligned
tubes, slidably moveable with respect to one another, such as, for
example, an outer tube and an inner tube, such as describe above
with respect to FIGS. 13A and 13B. The outer tube may include a
mating surface on or near its distal end to engage a mating surface
on the distal hub, or elsewhere on the implant. The outer tube
slidably engages an inner tube, which enters the outer tube at the
outer tube's proximal end. In one embodiment, a solid core is used
instead of an inner tube. Relative proximal and distal movement of
the inner and outer tube is preferably limited by a motion
limit.
[0148] In one embodiment, the motion limit includes at least one
cross pin. In other embodiments, the motion limit includes at least
one flare, annular ring, bump, or other suitable mechanism as is
well known to those of skill in the art. The inner tube extends
preferably to a handle as described above for operating the axially
moveable core. The engagement of the outer tube and the inner tube
of the axially moveable core may occur anywhere between the handle
and the implant along the length of the core.
[0149] In another embodiment, the inner tube includes a mating
surface on its distal end to engage a mating surface on the distal
hub of the implant. The inner tube slidably engages an outer tube,
which at least partially covers the inner tube at the inner tube's
proximal end. Relative proximal and distal movement of the inner
and outer tube is preferably limited by a motion limit as described
above, with the outer tube extending outside of the patient and
operably connected to a handle.
[0150] d. Multiple Guide Tube Mechanisms
[0151] Again referring to FIGS. 13A and 13B, various embodiments of
a multiple guide tube system may provide additional buckling and
bending support for any implant actuation shaft 334 traversing an
axis of an implant 100, as described above. Also, providing dual,
opposed guide tube allows decoupling of implant motion with respect
to the delivery catheter over a longer axial distance. For example,
a single guide tube having may allow for axial movement decoupling
over the length of the single guide tube, but dual guide tubes
allow for axial movement decoupling over the length defined by both
guide tubes.
[0152] Single guide tube embodiments are illustrated in FIGS. 16A
and 16B, and described in U.S. application Ser. No. 10/642,384,
filed Aug. 15, 2003, published as U.S. Publication No.
2005/0038470, incorporated by reference herein. Implants including
single guide tubes generally include a nut that is configured to
slide within the guide tube along a limited axial range of motion.
A tab, or protrusion, generally extends from the external side wall
of the nut into a slot provided in the guide tube wall. The
interference between the tab and the slot defines an axial range of
motion provided by the guide tube/sliding nut assembly. An axial
moveable core, or a torque rod, is generally coupled to the nut
(e.g., a threaded portion of the core screws into a mating portion
of the nut), and an implant is generally coupled to the distal end
of the single guide tube; therefore, the axial range of motion
defined by the guide tube/sliding nut assembly also defines an
axial range of motion between the axial moveable core and the
implant.
[0153] The axial range of motion between the axial moveable core
and the implant defines a distance over which axial movement of the
implant is decoupled from the axial moveable core. This decoupling
distance provides many clinical advantages. For example, once the
implant is expanded within the patient's heart, such as within the
LAA, it generally remains attached to the axial moveable core. By
remaining attached to the axial moveable core the clinician can
verify the implant position and sealing against the LAA wall prior
to final deployment, or release, from the axial moveable core.
[0154] Forces provided by the patient's moving heart act upon the
core-coupled implant. It is desirable that the implant is free to
move with the movement of the patient's beating heart, and that the
implant does not resist such forces. Resistance to heart movement
could cause the implant to become dislodged from its implantation
site, or to change it orientation in an undesired manner.
[0155] The guide tube/sliding nut assembly of the single guide tube
embodiments addresses this issue by providing limited decoupling
between the implant and an axial moveable core, as discussed above.
However, the decoupling length is generally limited by the length
of the guide tube slot, which is limited by the guide tube length.
It would be advantageous to increase the decoupling length. In one
embodiment, decoupling length is increased by employing a dual
guide tube configuration, such as described above with respect to
FIGS. 13A and 13B, and below. In addition, a dual guide tube
configuration can be employed with any of the deployment systems,
delivery systems, implants, catheters, and catheter systems
described herein.
[0156] Although the embodiments of FIGS. 13A and 13B illustrate one
pull cord or tether 312 configuration, certain preferred
embodiments of an implant delivery system 50 with a multiple guide
tubes do not include a pull cord 312. Removing the tether 312 can
reduce system bias from moment arms. Instead, an embodiment of an
implant delivery system 50 with a multiple guide tubes 130 and 160,
or 164 and 162, may be used with a threaded rod 342 configuration
as described above relating to FIGS. 14 and 15. In other
embodiments, an implant delivery system 50 with multiple guide
tubes does not use a threaded torque rod configuration in order to
reduce system bias from rotation of the implant 100 with respect to
a torque rod 342.
[0157] In certain embodiments an implant delivery system 50 with
multiple guide tubes can provide for some axial load decoupling by
providing slideable axial support to an implant 100, which is
attached at its proximal end 104 to a catheter system 300. After an
implant actuation shaft 334 is withdrawn from the distal end 102 of
an implant, the freely slideable concentric guide tubes 130 and 160
(or 162 and 164) may absorb some of the axial loading caused by the
beating of a heart 5, thereby allowing the implant 100 frame 101 to
deform with the beating of a heart 5 without imparting a complete
load to the remainder of the implant delivery system 50.
[0158] In one embodiment, a multiple guide tube configuration may
be used to simplify an implant release and recapture mechanism 200.
For example, the implant release and recapture mechanism 200
provides extendable support to a non-threaded shaft 334 that
provides axial force to the distal end 104 of an implant 100
without providing off-center moment arms or rotational loads
relative to the implant 100 during implant deployment or detachment
(such as is illustrated in one embodiment in FIGS. 21A-21C, as
described below).
[0159] In one embodiment, multiple guide tubes provide additional
axial support and guided slidable surfaces to the implant 100 while
preventing the shaft 334 from buckling over a the guide tube
lengths. Substantially coaxial tubes provide for easier alignment
of the ends 102 and 104 of an implant 100, and simplify the
re-insertion of a shaft 334 into an implant 100 during recapture of
detached or deployed implants. In addition, the multiple guide tube
configuration provides support for the distal loading provided by
the shaft 334, and works with any collapse or release mechanism.
However, it would be advantageous to provide the necessary proximal
loading to the proximal end 104 of an implant 100 in order to
radially reduce an implant 100 in a manner that did not impart
moment arms or rotational loads to the implant 100 during
deployment or detachment, as described in the following
embodiments.
[0160] e. Concentric Collapse and Release Mechanisms
[0161] FIGS. 17-21 illustrate cross-sectional views of various
embodiments of the distal end of an implant delivery system 50 that
includes an implant 100, an implant release and recapture mechanism
200, and a catheter system 300, which is attachable to a deployment
handle 400 (not illustrated). The illustrated embodiments provide
mechanisms to release an implant 100 from a catheter system 300
such that the implant's position and orientation do not change as a
result of the release process. For example, the illustrated
embodiments reduce bias and moment arms that cause deformation of
the implant 100 and loads within the implant delivery system 50.
Such bias and moment arms can cause the implant 100 to jump or
change orientation when released from the implant delivery system
50. These embodiments include a flexible interface between the
implant 100 and the catheter system 300. They also reduce off-axis
loading, thereby reducing moment arms and bending bias within the
system 50. Some embodiments include a tether line 210 system (not
shown) or a torque rod 340 configuration (not shown), as described
above.
[0162] Referring to FIGS. 17-20, the illustrated embodiments have
an implant 100 with a frame 101, a proximal end 104 and a distal
end 102, a stopping surface 126 at the distal end 102 of the
implant 100, and a disconnect mount interface 180 on the proximal
end 104 of the implant 100. The implant of FIGS. 17-20 is
schematically shown, and may have any suitable configuration as
described herein. The disconnect mount interface 180 has a finger
interface 182 which interacts with a flexible finger 238 on a
disconnect mount 236 on the catheter system 300, as described
below. Embodiments of the finger interface 182 may be in the form
of a protruding finger, an interlocking feature, a groove, a slot,
a window, or other similar features for releasably holding a
disconnect mount 236 flexible finger 238. The distal end 102 of the
implant 100 may also have an end cap 148. Various embodiments and
combinations of embodiments of the implant 100 may be used,
including but not limited to single and multiple guide tube
configurations, as describe above.
[0163] In some embodiments, the catheter system 300 includes a
disconnect mount 236 provided on the distal end 310 of a delivery
catheter 302. The disconnect mount 236 may be any mechanical mount
that releases one body from another without creating any or
substantial moment arms or bending bias. The disconnect mount 236
may provide releaseable concentric tension or concentric loading to
an implant 100. The loading imparted by the disconnect mount 236 to
the implant 100 may be in a proximal or distal direction. Distal
loading may be imparted to advance the entire catheter system 300
and implant 100 distally into a heart 5. Proximal loading may be
used in conjunction with a distally-loading shaft that works with
the disconnect mount 236 in placing an implant 100 in tension in
order to radially reduce a diameter of the implant 100. In one
embodiment, a disconnect mount 236 may include an annular ring,
which may be controlled to switch between an expanded and a reduced
diameter configuration. In one embodiment, the disconnect mount 236
acts like a stent, such as by radially expanding or contracting.
For example, the disconnect mount 236 can include a shape memory
alloy, such as nickel titanium, which self-expands. In other
embodiments, the disconnect mount 236 expands under positive force,
such as in response to radial forces provided by an inflation
balloon.
[0164] The terms "concentric tension," "concentric loading," and
"concentric force" are broad terms intended to have their ordinary
meanings. In addition, these terms refer to forces that are
provided either in an inward or outward direction with respect to a
longitudinal axis, and forces symmetrical about a longitudinal
axis. Some of the symmetrical forces may be in directions with
components along an axis extending distally or proximally along the
longitudinal axis, and may also be perpendicular to the
longitudinal axis. For example, in one embodiment, a disconnect
mount is a generally cylindrical structure having a longitudinal
axis and flexible fingers extending longitudinally from its end.
The flexible fingers are generally biased to flex inward, towards
the longitudinal axis, or outward, away from the longitudinal axis.
The fingers are generally aligned with openings in a mating portion
of the implantable device. The openings generally extend around or
within a portion of the circumference of the mating portion of the
implantable device. As the fingers flex, they provide concentric
force that maintains a portion of the fingers within the windows of
the implant mating surface. When the fingers are engaged with the
implant mating portion, proximal or distal force can thereafter be
applied to the implant with the disconnect mount to move the
implant, or at least the portion of the implant coupled to the
disconnect mount, in a proximal or distal direction.
[0165] Concentric forces can be used to release the implant from a
delivery system without applying bias to the implant, as described
herein. For example, by concentrically releasing tension from the
proximal end of the implant, the implant will not substantially
jump, move, or otherwise change its orientation with respect to the
delivery system when released.
[0166] In some embodiments, the disconnect mount includes two,
three, four, or a plurality of actuating fingers, such as ten or
more actuating fingers. As illustrated, the disconnect mount 236
has at least two flexible fingers 238 which engage recesses,
windows, or corresponding structure in a disconnect mount interface
180 located at the proximal end 104 of an implant 100.
[0167] The disconnect mount 236 can be created from rod stock using
a combination Swiss screw machine and Electrical Discharge
Machining (EDM) operation to fashion at least two substantially
symmetric flex fingers 238 with protruding portions 240. The
disconnect mount interface 180 may have a finger interface 182 that
is specially adapted to releasably hold a disconnect mount 236
flexible finger 238 in place. The catheter system 300 has an
implant actuation shaft 334 that extends through the catheter body
302 and through the implant 100 to touch the stopping surface 126
at the distal end 102 of the implant 100. When the implant
actuation shaft 334 provides a sufficient load in the distal
direction against the stopping surface 126 while a tensile load in
a proximal direction is applied to the proximal end 104 of the
implant 100, the implant 100 can be held in a radially-reduced
configuration which overcomes the normal shape-memory bias toward a
radially-expanded configuration for the implant 100.
[0168] When the implant actuation shaft 334 is refracted proximally
into the catheter body 302, the implant 100 tends to return to its
radially-expanded configuration by moving proximally (e.g., see
FIGS. 17, 19, 20). When the tensile loading on the proximal end 104
of the implant 100 is reduced by allowing the proximal end 104 of
the implant to move distally, the implant 100 tends to return to
its radially-expanded configuration by moving distally (e.g., see
FIGS. 18, 21). The retraction of the implant actuation shaft 334
and reduction in tensile loading on the proximal end 104 of the
implant 100 may occur independently, simultaneously, or
incrementally to control the relative axial placement of the
implant 100 in a LAA 10.
[0169] Still referring to FIGS. 17-20, there is illustrated various
embodiments of a disconnect mount 236 with a corresponding
disconnect mount interface 180 and a lock tube 234. The disconnect
mount interface 180 may have a finger interface 182 that is adapted
to releasably hold a disconnect mount 236 flexible finger 238 in
place. The protruding portions 240 of the flex fingers 238 are
captured within cutouts, recesses, or windows located on the finger
interface 182 of the disconnect mount interface 180, which is
located on a proximal portion 104 of the implantable device 100.
For example, the implant's 100 finger interface 182 can include
cutouts that releasably engage flex fingers 238 of the delivery
system. While the flex fingers 238 hold on to the proximal end 104
of the implant 100, an implant actuation shaft 334 extends through
the implant 100 and pushes distally against the distal end 102 of
the implant 100. As described above, the implant 100 can be made
self-expanding, so that when the distal pushing force exerted by
the implant actuation shaft 334 or the proximal pulling (or
holding) force applied by the flex fingers 238 is removed the
implant 100 automatically radially expands to a predetermined size
and shape. The implant 100 can be maintained in its reduced
diameter configuration by holding the proximal end 104 of the
implant 100 with the flex fingers 238 and pushing against the
distal end 102 of the implant 100 with the implant actuation shaft
334. In this configuration, relative movement between the inner
implant actuation shaft 334 and the concentric, outer flex fingers
238 controls implant 100 expansion and collapse.
[0170] An embodiment of flex fingers 238 can be biased to extend
either radially inwardly or radially outwardly. In embodiments
where the flex fingers 238 are biased to extend radially inwardly,
the flex fingers 238 engage a disconnect mount interface 180 to
lock an implant 100 to the implant delivery system 50 when a
structure prevents the flex fingers 238 from extending radially
inwardly. In one embodiment the flex fingers 238 are held in place
with a disconnect mount interface 180 of the implant 100 by the
presence of an implant actuation shaft 334 which extends through
the implant 100 and prevents the flex fingers 238 from extending
radially inwardly. When the implant actuation shaft 334 is
withdrawn proximally toward the catheter system 300 past the
disconnect mount 236, the open space created by the removal of the
implant actuation shaft 334 leaves room for the flex fingers 238 to
extend radially inwardly under its bias. This radial movement of
the flex fingers 238 releases the disconnect mount 236 from the
disconnect mount interface 180, thereby releasing the implant 100
from the implant delivery system 50.
[0171] In embodiments where the flex fingers 238 are biased to
extend radially outwardly, the flex fingers 238 engage a disconnect
mount interface 180 to lock an implant 100 to the implant delivery
system 50 in its natural state. When a structure or a load causes
the flex fingers 238 to extend radially inwardly, the radial
movement of the flex fingers 238 releases the disconnect mount 236
from the disconnect mount interface 180, thereby releasing the
implant 100 from the implant delivery system 50.
[0172] In some embodiments, the flex fingers 238 are held in the
finger interface 182 by a lock tube 234. The lock tube 234 can be
axially slideable with respect to the catheter body 302 and with
respect to a disconnect mount 236. In one embodiment, the lock tube
234 has a threaded portion (not illustrated) that threads into the
disconnect mount 236 and extends under and between the flex fingers
238, thereby preventing the flex fingers 238 from collapsing inward
(in a manner similar to the embodiment illustrated in FIGS.
17-18).
[0173] In another embodiment the lock tube 234 has a threaded
portion (not illustrated) that threads over the disconnect mount
236 and extends over the flex fingers 238, thereby preventing the
flex fingers 238 from expanding outward (in a manner similar to the
embodiment illustrated in FIGS. 19-20). In other embodiments, a
lock tube 234 can be threaded to a catheter body 302, or a lock
tube 234 may not be threaded and retains its axial positioning with
respect to a disconnect mount 236 until the user actuates the lock
tube to release the flex fingers 238. In other embodiments, an
implant actuation shaft 334 can include a protruding feature, such
as a tab, key or pin, that engages a lock tube 234 and allows
torque to be transferred from the implant actuation shaft 334 to
the lock tube 234.
[0174] FIGS. 17A-17C illustrate an embodiment of a disconnect mount
236 having flex fingers 238, a corresponding disconnect mount
interface 180, and a lock tube 234 at least partially contained
within a catheter body 302. In certain embodiments illustrated in
FIGS. 17A-17C, the flex fingers 238 can be biased to extend
radially outwardly or inwardly to apply concentric loading, as
discussed above.
[0175] In one embodiment, the flex fingers 238 are biased
outwardly. The flex fingers 238 can also include a proximal
inclined surface 242 at the transition from the flex finger 238 to
the protruding portion 240. Referring to embodiments in FIG. 17B,
after the implant 100 is deployed or radially expanded in a LAA 10
(not illustrated here), anchors 118 (not illustrated here) on the
implant frame 101 secure the implant 100 within the LAA 10. The
interface between the implant 100 and the disconnect mount 236
provides concentric loading to the implant 100. In one embodiment
the concentric loading is concentric tension. At this point, the
lock tube 234 can be withdrawn proximally away from contact with
the flex fingers 238, allowing the flex fingers 238 to deflect
inwardly.
[0176] When the flex fingers 238 are moved proximally with respect
to the implant 100, such as when the catheter system 300 is
withdrawn proximally away from the expanded implant 100 in the LAA
10, the inside edge of the disconnect mount interface 180 can press
onto the proximal inclined surface 242, which provides a radially
inward force to the flex finger 238. As illustrated, the embodied
disconnect mount interface 180 uses a finger interface 182 in the
form of an internal surface of a proximal end 104 of the implant
100. The radially inward force causes the flex fingers 238 or at
least a distal portion of the flex fingers 238 to move radially
inwardly.
[0177] The amount of deflection in the flex fingers 238 that
effective to release the disconnect mount 236 from the disconnect
mount interface 180 may depend on the thickness of the lock tube
240 alone (as is illustrated in FIG. 17B), or it may depend on the
removal of the implant actuation shaft 334 proximal to the flex
fingers 238 (as is illustrated in FIG. 17C) in order to release the
implant 100. Once the flex fingers 238 are sufficiently radially
deflected, the implant 100 is disconnected from the delivery system
50 without imparting any or any substantial moment arms, bending
bias, or rotational bias with respect to the implant 100. As
depicted in FIG. 17C, once the implant 100 is detached, the flex
fingers 238 will bias toward their natural state (inward bias is
illustrated in solid lines and outward bias is illustrated in
dotted lines).
[0178] In another embodiment illustrated in FIGS. 17A-17C, the flex
fingers 238 are biased inwardly. Referring to embodiments in FIG.
17B, after the implant 100 is deployed and radially expanded in a
LAA, anchors on the implant frame 101 secure the implant 100 within
the LAA. The interface between the implant 100 and the disconnect
mount 236 provides concentric loading to the implant 100. In one
embodiment the concentric loading is concentric tension. At this
point, the lock tube 234 can be withdrawn proximally away from
contact with the flex fingers 238, allowing the flex fingers 238 to
deflect inwardly to their natural, biased state. The amount of
deflection in the flex fingers 238 that is effective to release the
disconnect mount 236 from the disconnect mount interface 180 may
depend on the thickness of the lock tube 240 alone (as is
illustrated in FIG. 17B), or it may depend on the removal of the
implant actuation shaft 334 proximal to the flex fingers 238 (as is
illustrated in FIG. 17C) in order to release the implant 100. Once
the flex fingers 238 are sufficiently radially deflected, the
implant 100 is disconnected from the delivery system 50 without
imparting any or any substantial moment arms, bending bias, or
rotational bias with respect to the implant 100. As depicted in
FIG. 17C, once the implant 100 is detached, the flex fingers 238
will bias toward their natural state (inward bias is illustrated in
solid lines and outward bias is illustrated in dotted lines). When
the flex fingers 238 are biased inwardly, the lock tube 334 can be
slideably engaged under the flex fingers 238 to deflect the fingers
outwardly.
[0179] In some embodiments, when the implant 100 is in its
collapsed configuration the tension created by a load between the
implant actuation shaft 334 and the flex fingers 238 may create
pullout forces sufficient to cause inward flex of the flex fingers
238 and potentially pinch underlying structure, such as the implant
actuation shaft 334, which could cause the implant 100 to bind.
However, the lock tube 234 can prevent this from happening and can
serve as a buffer between the flex fingers 238 and the underlying
implant actuation shaft 334. This provides smooth and uninterrupted
movement of the implant actuation shaft 334 in and out of the
implant 100 during expansion. It also allows for smooth disconnect
during release of the implant 100 ("boing-less" release, or
releasing without the implant "jumping", moving, or changing its
position or orientation).
[0180] In some embodiments, markers 204 are provided at locations
visible under fluoroscopy or other means known in the art of
visualizing the manipulation or implantation of devices within a
body. The markers 204, which can be radiopaque in nature, can be
placed on any surfaces to assist in deployment or recapture of an
implant 100, as is described above for the embodiment of a marker
360 as shown in FIG. 14, which advantageously assists in locating
the position of a distal end 344 of an axially moveable core 342.
In various embodiments, a marker 204 comprises a radiopaque band,
dot, coating, or material that is attached to a disconnect mount
236, a distal end 104 of an implant 100, and a portion of an
implant actuation shaft 334. Marker 204 preferably is made from a
material readily identified after insertion into a patient's body
by using visualization techniques that are well known to those of
skill in the art. In one embodiment, the marker 204 is made from
gold, or tungsten, or any such suitable material, as is well known
to those of skill in the art. In another embodiment, marker 204 is
welded, soldered, or glued onto a structure for marking. In one
embodiment, the use of markers 204 segments is useful to discern
the radial orientation of the implant 100 within the body.
[0181] Referring to FIGS. 18A-18C, there is illustrated an
embodiment of a disconnect mount 236 with flex fingers 238, a
corresponding disconnect mount interface 180, and a lock tube 234
at least partially contained within a catheter body 302. The
embodiment illustrated in FIGS. 18A-18C is similar in many ways
with the embodiment illustrated in FIGS. 17A-17C, and includes many
of the same components described above. The embodiment illustrated
in FIGS. 18A-18C can optionally include markers (not illustrated).
The illustrated embodiment also includes a lumen 335 in the implant
actuation shaft 334, and lumens 150 in an end cap 148 at the distal
end 102 of the implant 100. In addition, the illustrated
embodiments can be deployed in a proximal or distal direction, as
discussed in greater detail below. Any of the features of
embodiments illustrated in FIGS. 17 and 18 can be used in
conjunction with each other, along with combinations of embodiments
illustrated in FIGS. 19-21, or any other embodiments of the
invention described herein.
[0182] Referring to FIGS. 18A-18C, an embodiment of a catheter
system 300 has an implant actuation shaft 334 which extends through
the catheter body 302 and can extend through the implant 100 to
touch the stopping surface 126 at the distal end 102 of the implant
100. When the implant actuation shaft 334 provides a sufficient
load in the distal direction against the stopping surface 126 while
a proximally-directed load is applied to the proximal end 104 of
the implant 100, the implant 100 can be held in sufficient tension
to overcome the normal shape-memory bias toward a radially-expanded
configuration for the implant 100, resulting in an implant 100 with
a radially-reduced configuration. The embodiment of the system 50
illustrated in FIGS. 17A-17C depicts steps where the implant
actuation shaft 334 is retracted proximally into the catheter body
302 and the implant 100 tends to return to its radially-expanded
configuration as of its distal end 102 moving proximally.
[0183] The embodiment of the system 50 illustrated in FIGS. 18A-18C
depict steps where the concentric tensile loading on the proximal
end 104 of the implant 100 is reduced by allowing the proximal end
104 of the implant 100 to move distally such that the implant 100
as a whole tends to return to its radially-expanded configuration
by moving distally. The retraction of the implant actuation shaft
334 and reduction in concentric tensile loading on the proximal end
104 of the implant 100 may occur independently, simultaneously, or
incrementally to control the relative axial placement of the
implant 100 in a LAA 10.
[0184] The lumen 335 in the implant actuation shaft 334 may contain
radiopaque or contrast materials injected into the catheter system
300 through ports in the deployment handle 400, as described above
and below. The exit point for contrast to exit the lumen 335 may be
at the distal tip of the implant actuation shaft 334 or along any
exit port (not illustrated) along the implant actuation shaft 334.
One embodiment of a lumen 335 is similar to the lumen 350 of the
tubular torque rod 340 described above and illustrated in FIG. 14.
The lumen 335 preferably allows visualization dye to flow through
the lumen 335 of the implant actuation shaft 334 and through the
implant frame 101 or through at least one lumen 150 of the implant
end cap 148, and into the LAA 10 (not illustrated here). Such usage
of visualization dye is useful for clinical diagnosis and testing
of the position of the implant 100 within the LAA 10 or other body
openings.
[0185] FIGS. 19A-19C and 20A-20C illustrate additional embodiments
of a disconnect mount 236 having flex fingers 238, a corresponding
disconnect mount interface 180, and a catheter body 302, which is
at least partially contained within a lock tube 234. The disconnect
mount 236 provides concentric loading to the implant 100 without
imparting rotational loads to the implant 100. The flex fingers 238
can be biased to extend radially outwardly or inwardly, as
discussed above. In one embodiment, the flex fingers 238 are biased
inwardly. The flex fingers 238 can also include a proximal inclined
surface 242 at the transition from the flex finger 238 to the
protruding portion 240. As illustrated, the embodied disconnect
mount interface 180 uses a finger interface 182 in the form of
slots or windows in a wall of a proximal end 104 of the implant
100. Referring to embodiments in FIGS. 19B and 20B, after the
implant 100 is deployed and radially expanded in a LAA 10 (not
illustrated here), anchors 118 (not illustrated here) on the
implant frame 101 secure the implant 100 within the LAA 10. The
interface between the implant 100 and the disconnect mount 236
provides concentric loading to the implant 100. In one embodiment
the concentric loading is concentric tension.
[0186] The lock tube 234 can be withdrawn proximally away from
contact with the flex fingers 238, allowing the flex fingers 238 to
deflect outwardly. When the flex fingers 238 are moved proximally
with respect to the implant 100, such as when the catheter system
300 is withdrawn proximally away from the expanded implant 100 in
the LAA 10, the inside edge of the disconnect mount interface 180
can press onto the proximal inclined surface 242, which provides a
radially outward force to the flex fingers 238. The radially
outward force causes the flex fingers 238 or at least a distal
portion of the flex fingers 238 to move radially outwardly. Once
the flex fingers 238 are sufficiently radially deflected, the
implant 100 is disconnected from the delivery system 50 without
imparting any or any substantial moment arms or bending bias with
respect to the implant 100. As depicted in FIGS. 19C and 20C, once
the implant 100 is detached, the flex fingers 238 will bias toward
their natural state (inward bias is illustrated in solid lines and
outward bias is illustrated in dotted lines).
[0187] In another embodiment illustrated in FIGS. 19A-19C and
20A-20C, the flex fingers 238 are biased outwardly. Referring to
embodiments in FIGS. 19B and 20B, after the implant 100 is deployed
and radially expanded in a LAA, anchors (not illustrated) on the
implant frame 101 secure the implant 100 within the LAA. The
interface between the implant 100 and the disconnect mount 236
provides concentric loading to the implant 100. In one embodiment
the concentric loading is concentric tension. At this point, the
lock tube 234 can be withdrawn proximally away from contact with
the flex fingers 238, allowing the flex fingers 238 to deflect
outwardly in their natural state.
[0188] Once the flex fingers 238 are sufficiently radially
deflected, the implant 100 is disconnected from the delivery system
50 without imparting any or any substantial moment arms or bending
bias with respect to the implant 100. As depicted in FIGS. 19C and
20C, once the implant 100 is detached, the flex fingers 238 will
bias toward their natural state (inward bias is illustrated in
solid lines and outward bias is illustrated in dotted lines). When
the flex fingers 238 are biased outwardly, the lock tube 334 can be
slideably engaged over the flex fingers 238 (not illustrated in
FIG. 19C) or over a finger pivot axis 239 (as illustrated in FIG.
20C) in order to deflect the flex fingers 238 inwardly to
facilitate extraction of the implant delivery system and/or
catheter system from the body.
[0189] FIGS. 20A-20C illustrate an embodiment of a disconnect mount
236 with flex fingers 238, a corresponding disconnect mount
interface 180, and a catheter body 302 at least partially contained
within a lock tube 234, as described above. The illustrated
embodiment of FIGS. 20A-20C includes a lock tube 234 that only
partially surrounds the flex fingers 238 of the disconnect mount
236. In addition, a finger pivot axis 239 located proximally to the
flex fingers 238 defines the axis about which the flex fingers
rotate. In leaving the lock tube 234 proximal to the flex fingers
238 and at least a portion of the disconnect mount 236, the lock
tube 234 can maintain a relatively smaller lock tube 234 diameter
than would be the case if the lock tube 234 had to enclose the
entire diameter of the disconnect mount 236, resulting in easier
insertion of the catheter system 300 into the body. The finger
pivot axis 239 can be formed as a crease in an extended flex finger
238 located proximally to an increase in disconnect mount 236
diameter, or as a physical hinge or pin in a linkage mechanism to
create the disconnect mount 236.
[0190] All of the foregoing embodiments, including those of FIGS.
17A-20C could include an implant that has a single or dual guide
tubes, as discussed above. For example, in the embodiments of FIGS.
17A-20C, the implant 100 could include a distal, outer guide tube
attached to the distal end 102 of the implant 100, and a
concentric, proximal, inner guide tube attached to the proximal end
104 of the implant 100.
[0191] FIGS. 21A-21C illustrate another embodiment of a distal
portion of an implant delivery system 50, which includes an implant
100, an implant release and recapture mechanism 200, a catheter
system 300, and a deployment handle 400 (not illustrated). The
illustrated embodiments include an implant 100 that has a proximal
end 104, a distal end 102 with a stopping surface 126, a frame 101,
tissue anchors 118, and a disconnect mount interface 180 on the
proximal end 104 of the implant 100. The disconnect mount interface
180 has a finger interface 182 which interacts with a flexible
finger 238 on a disconnect mount 236 on the catheter system 300 to
apply releasable concentric loads in a manner similar to the
embodiments described above. Embodiments of the finger interface
182 may be in the form of a protruding finger, an interlocking
feature, a groove, a slot, a window, or other similar features for
releasably holding, engaging and/or coupling a disconnect mount
flexible finger 238. The distal end 102 of the implant 100 may also
have an end cap 148 with zero or more lumens 150. Various
embodiments and combinations of embodiments of the implant 100 may
be used, including but not limited to single or multiple guide tube
configurations, as described above.
[0192] As illustrated, FIGS. 21A-21C show an implant with a
multiple guide tube configuration as is described above relating to
FIGS. 13A and 13B. The implant 100 has an outer guide tube 162
which is also a distal guide tube 130, and an inner guide tube 164
which is also a proximal guide tube 160.
[0193] In some embodiments the catheter system 300 has a disconnect
mount 236 provided on the distal end 310 of a delivery catheter
302. The disconnect mount 236 may be any mechanical mount that
releases one body from another without creating any or any
substantial moment arms or bending bias. The disconnect mount 236
may provide releaseable concentric tension or concentric loading to
an implant 100. The loading imparted by the disconnect mount 236 to
the implant 100 may be in a proximal or distal direction. For
example, in some embodiments, the concentric loading applies
tension in a proximal direction with respect to the implant, and in
other embodiments, the concentric loading applies a pushing force
in a distal direction.
[0194] Distal loading may be imparted to advance the entire
catheter system 300 and implant 100 distally into a heart. Proximal
loading may be used in conjunction with a distally-loading shaft
that works with the disconnect mount 236 in placing an implant 100
in tension in order to radially reduce a diameter of the implant
100. In one embodiment, a disconnect mount 236 includes an annular
ring that is controlled to switch between an expanded and a reduced
diameter configuration. In one embodiment, the disconnect mount 236
may act like a stent, and radially expand when activated.
[0195] In other embodiments, a disconnect mount includes two,
three, four, or a plurality of actuating fingers, such as ten or
more actuating fingers. As illustrated, the disconnect mount 236
has at least two flexible fingers 238 which may engage within
recesses, windows, or corresponding structure in a disconnect mount
interface 180 on a proximal end 104 of an implant 100. The
disconnect mount interface 180 may have a finger interface 182 that
is specially adapted to releasably hold a disconnect mount 236
flexible finger 238 in place.
[0196] The disconnect mount 236 can be created from rod stock using
a combination Swiss screw machine and Electrical Discharge
Machining (EDM) operation to fashion at least two substantially
symmetric flex fingers 238 with protruding portions 240. The
disconnect mount interface 180 may have a finger interface 182 that
is specially adapted to releasably hold a disconnect mount 236
flexible finger 238 in place.
[0197] The protruding portions 240 of the flex fingers 238 are
captured within cutouts, recesses, or windows located on the finger
interface 182 of the disconnect mount interface 180, which is
located on a proximal portion 104 of the implantable device 100.
For example, the implant's finger interface 182 can include cutouts
that releasably engage flex fingers 238 of the delivery system
50.
[0198] In some embodiments, the catheter system 300 has an implant
actuation shaft 334 which extends through the catheter body 302 and
can extend through the implant 100 to touch the stopping surface
126 at the distal end 102 of the implant 100. When the implant
actuation shaft 334 provides a sufficient load in the distal
direction against the stopping surface 126 while a tensile load in
a proximal direction is applied to the proximal end 104 of the
implant 100, the implant 100 can be held in a radially-reduced
configuration. This overcomes the shape-memory bias toward a
radially-expanded configuration for the implant 100.
[0199] When the implant actuation shaft 334 is refracted proximally
into the catheter body 302, the implant 100 tends to return to its
radially-expanded configuration by moving proximally. When the
tensile loading on the proximal end 104 of the implant 100 is
reduced by allowing the proximal end 104 of the implant to move
distally, the implant 100 tends to return to its radially-expanded
configuration by moving distally (as is depicted in the embodiment
illustrated in FIGS. 21A-21C). The refraction of the implant
actuation shaft 334 and reduction in tensile loading on the
proximal end 104 of the implant 100 may occur independently,
simultaneously, or incrementally to control the relative axial
placement of the implant 100 in a LAA 10.
[0200] In some embodiments, a lumen 335 (not illustrated) in the
implant actuation shaft 334 may contain radiopaque or contrast
materials injected into the catheter system 300 through ports in
the deployment handle 400, as described above and below. In some
embodiments, the implant actuation shaft 334 may be constructed of
a flexible material, such as a puzzle lock profile 600, as
described relating to FIG. 25A below.
[0201] In the illustrated embodiment of FIGS. 21A-21C, the implant
actuation shaft 334 includes a threaded portion 336. In this
embodiment, any rotational loads imparted due to the threadable
engagement between the hub 236 and the implant actuation shaft 334
are transferred within the implant release and recapture mechanism
200 on the side with the catheter system 300, thereby avoiding
rotational loading of the implant 100 within the LAA 10.
[0202] The threaded portion 336 of the implant actuation shaft 334
may be manufactured by a lathing or machining process from the same
material as the implant actuation shaft 334, or threaded portion
336 may be a separate piece that is bonded, welded, soldered,
braided, or otherwise attached to a portion of the implant
actuation shaft 334. In the illustrated embodiment, rotating the
implant actuation shaft 334 causes it to advance longitudinally.
For example, the threaded portion 336 engages a threaded portion
246 of a disconnect mount 236 in a screw-like manner. Rotating the
implant actuation shaft 334 when the threaded portions 336, 246 are
engaged causes the shaft 334 to advance proximally or distally,
depending upon the direction of shaft rotation. When the threads
are disengaged, the actuation shaft 334 can slide with respect to
the implant 100.
[0203] The illustrated embodiment can provide anywhere in the range
of 0%-100% of the collapse of the implant 100 by axially sliding a
implant actuation shaft 334. In some embodiments, the implant
actuation shaft 334 causes 25%, 30%, 40%, 50%, 60%, 70%, 75%, 80%,
90%, or 95% of the collapse or expansion of the implant 100, and
can lock the implant in a partially-expanded or partially-reduced
state. This provides the advantage of allowing the clinician to
verify proper position and orientation of the implant 100 in small
steps as the implant 100 is deployed within the patient's body.
[0204] Expansion of the implant 100 occurs while the threaded
portion 336 of the implant actuation shaft 334 is engaged with the
threaded portion 246 the disconnect mount 236. While the threaded
portion 336 of the implant actuation shaft 334 is engaged with the
threaded portion 246 the disconnect mount 236, the implant
actuation shaft 334 is essentially locked in place unless
sufficient torque is provided to rotate the two threaded portions
336 and 246 with respect to one another. This allows the implant
100 to be held or maintained in a fully or partially
radially-reduced configuration.
[0205] While the flex fingers 238 hold the proximal end 104 of the
implant 100 with concentric tensile force, an implant actuation
shaft 334 extends through the implant 100 and pushes distally
against the distal end 102 of the implant 100. As described above,
the implant 100 can be made self-expanding, so that when the distal
pushing force exerted by the implant actuation shaft 334 or the
concentric proximal pulling (or holding) force applied by the flex
fingers 238 is removed or reduced the implant 100 automatically
radially expands to a predetermined size and shape. The implant 100
can be maintained in its reduced diameter configuration by holding
the proximal end 104 of the implant 100 with the flex fingers 238
and pushing against the distal end 102 of the implant 100 with the
implant actuation shaft 334. In this configuration, relative
movement between the inner implant actuation shaft 334 and the
concentric, outer flex fingers 238 controls implant 100 expansion
and collapse.
[0206] In some embodiments, the flex fingers 238 are biased to
extend either radially inwardly or radially outwardly. In
embodiments where the flex fingers 238 are biased to extend
radially inwardly, the flex fingers 238 engage a disconnect mount
interface 180 to lock an implant 100 to the implant delivery system
50 when a structure prevents the flex fingers 238 from extending
radially inwardly.
[0207] In one embodiment, as illustrated in FIGS. 21A-21C, the flex
fingers 238 may be held in place with a disconnect mount interface
180 of the implant 100 by the presence of an implant actuation
shaft 334 which extends through the implant 100 and prevents the
flex fingers 238 from extending radially inwardly. When the implant
actuation shaft 334 is withdrawn proximally toward the catheter
system 300 past the disconnect mount 236, the open space created by
the removal of the implant actuation shaft 334 leaves room for the
flex fingers 238 to extend radially inwardly under its bias. This
radial movement of the flex fingers 238 releases the disconnect
mount 236 from the disconnect mount interface 180, thereby
releasing the implant 100 from the implant delivery system 50.
[0208] In embodiments where the flex fingers 238 are biased to
extend radially outwardly, the flex fingers 238 engage a disconnect
mount interface 180 to lock an implant 100 to the implant delivery
system 50 in its natural state. When a structure or a load causes
the flex fingers 238 to extend radially inwardly the radial
movement of the flex fingers 238 releases the disconnect mount 236
from the disconnect mount interface 180, thereby releasing the
implant 100 from the implant delivery system 50 with significantly
reduced or non-existent bending bias and rotational bias.
[0209] In some embodiments of an implant delivery system 50,
markers 204 (not illustrated) may be placed in locations visible by
fluoroscopic or other means known in the art of visualizing the
manipulation or implantation of devices within a body. The markers
204, which can be radiopaque in nature, can be placed on any
surfaces to assist in deployment or recapture of an implant 100, as
is described above for the embodiment of a marker 360 as shown in
FIG. 14, which advantageously assists in locating the position of a
distal end 344 of an axially moveable core 342.
[0210] In various embodiments, a marker 204 comprises a radiopaque
band, dot, coating, or material that is attached to a disconnect
mount 236, a distal end 104 of an implant 100, and a portion of an
implant actuation shaft 334. Marker 204 preferably is made from a
material readily identified after insertion into a patient's body
by using visualization techniques that are well known to those of
skill in the art. In one embodiment, the marker 204 is made from
gold, or tungsten, or any such suitable material, as is well known
to those of skill in the art. In another embodiment, marker 204 is
welded, soldered, or glued onto a structure for marking. In one
embodiment, the use of markers 204 segments is useful to discern
the radial orientation of the implant 100 within the body.
[0211] Referring once again to FIGS. 21A-21C, flex fingers 238 can
be biased to extend radially outwardly or inwardly, as discussed
above. In one embodiment, the flex fingers 238 are biased
outwardly. The flex fingers 238 can also include a proximal
inclined surface 242 at the transition from the flex finger 238 to
the protruding portion 240. As illustrated, the embodied disconnect
mount interface 180 uses a finger interface 182 in the form of
slots or windows in a wall of a proximal end 104 of the implant
100.
[0212] Referring to embodiments in FIG. 21B, after the implant 100
is deployed and radially expanded in a LAA 10 (not illustrated
here), anchors 118 on the implant frame 101 secure the implant 100
within the LAA 10. As depicted in FIG. 21C, the implant actuation
shaft 334 can be withdrawn proximally away from contact with the
flex fingers 238, allowing the flex fingers 238 to deflect
inwardly. When the flex fingers 238 are moved proximally with
respect to the implant 100, such as when the catheter system 300 is
withdrawn proximally away from the expanded implant 100 in the LAA
10, the inside edge of the disconnect mount interface 180 can press
onto the proximal inclined surface 242 (not shown), which provides
a radially inward force to the flex fingers 238.
[0213] The radially inward force causes the flex fingers 238 or at
least a distal portion of the flex fingers 238 to move radially
inwardly. Once the flex fingers 238 are sufficiently radially
deflected, the implant 100 is disconnected from the delivery system
50 without imparting any or any substantial moment arms or bending
bias with respect to the implant 100. As depicted in FIG. 21C, once
the implant 100 is detached, the flex fingers 238 will bias toward
their natural state (inward bias is illustrated in solid lines and
outward bias is illustrated in dotted lines).
[0214] In another embodiment illustrated in FIGS. 21A-21C, the flex
fingers 238 are biased inwardly. Referring to embodiments in FIG.
21B, after the implant 100 is deployed and radially expanded in a
LAA 10 (not illustrated here), anchors 118 on the implant frame 101
secure the implant 100 within the LAA 10. As depicted in FIG. 21C,
the implant actuation shaft 334 can be withdrawn proximally away
from contact with the flex fingers 238, allowing the flex fingers
238 to deflect inwardly in their natural state. Once the flex
fingers 238 are sufficiently radially deflected, the implant 100 is
disconnected from the delivery system 50 without imparting any
moment aims or bending bias with respect to the implant 100. As
depicted in FIG. 21C, once the implant 100 is detached, the flex
fingers 238 will bias toward their natural state (inward bias is
illustrated in solid lines and outward bias is illustrated in
dotted lines). When the flex fingers 238 are biased inwardly, the
implant actuation shaft 334 can be slideably engaged under the flex
fingers 238 in order to deflect the flex fingers 238 outwardly.
[0215] As illustrated in FIGS. 21A-C, some embodiments include a
flexible sock 392 positioned between the catheter body 302 and the
disconnect mount 236. The sock 392 is discussed in greater detail
below. In some embodiments, a catheter body 302 may be directly
mounted to a disconnect mount 236.
[0216] In the illustrated embodiments described herein, an implant
deployment system generally includes an implant coupled to a
catheter with a release mechanism. The system also generally
includes a mechanism to expand or contract the diameter of the
implant. Although many of the embodiments describe the release
mechanism coupled to the distal end of the catheter and the
proximal end of the implant, it should be well understood by those
of skill in the art that in other embodiments, the release
mechanism is coupled to the distal end of the implant.
[0217] In addition, when the release mechanism is coupled to the
proximal end of the implant, the implant is expanded by either
moving the distal end of the implant proximally, by moving the
proximal end of the implant distally, or by moving both ends
towards the center of the implant. In many cases, the proximal end
of the implant is held in place with respect to the patient's LAA
and the distal end of the implant is allowed to move proximally
under the self-expanding forces of the implant. However, in some
situations, for example when treating patients that have a very
short LAA, it may be desirable to perform a different procedure.
For example, in such situations the clinician may desire to hold
the distal end of the implant in place with respect to the
patient's LAA while moving the proximal end of the implant
distally; otherwise, the proximal end of the implant could wind up
positioned within the patient's left atrium.
[0218] In some embodiments, the implant is expanded "in a distal
direction" as just described by coupling the release mechanism to
the distal end of the implant and then releasing tension from the
implant's proximal end. Once the implant is radially expanded, the
implant is released and the catheter is removed. For example, in
one embodiment, the catheter and/or release mechanism extends
through the implant's proximal end and its body to contact a
portion near the distal end of the implant from within the
implant.
[0219] The term "in a distal direction" refers to the steps of
keeping the distal end of the implant in a relatively,
substantially fixed position with respect to the deployment site
while advancing the proximal end of the implant distally.
Similarly, the term "in a proximal direction" refers to the steps
of holding the proximal end of the implant in a relatively,
substantially fixed position with respect to the deployment site
while advancing the distal end of the implant proximally.
[0220] Therefore, the deployment systems can be configured to
deploy in a proximal or a distal direction (or both). In addition,
for any deployment direction configuration, the deployment systems
can be further configured such that the release mechanism couples
to either the proximal or distal end of the implant.
[0221] Referring to FIGS. 21D and 21E, in one embodiment the
deployment system 50 is configured to deploy the implant 100 in a
distal direction, and the release mechanism 200 is coupled to the
proximal end 104 of the implant 100. A shaft, such as an axially
moveable core 304, extends through the implant 100 and contacts the
distal end 102 of the implant 100. The core 304 includes an inner
core 305 and an outer core 307, which are coaxially aligned and can
be longitudinally moved with respect to each other.
[0222] The outer core 307 includes two longitudinally spaced
locking mechanisms. The first locking mechanism 309 is configured
to engage and secure the outer core 307 to a mating portion 313 of
the distal end 310 of the catheter 302. The second locking
mechanism 311 is configured to engage and secure the outer core 307
to a mating portion 345 of the implant 100. In one embodiment, the
locking mechanisms 309 and 311 include two radially offset cams 347
and 349 configured to engage mating surface slots 351 and 353,
respectively, extending annularly within corresponding catheter
mating portion 313 and implant mating portion 345,
respectively.
[0223] Initially the cams 347 and 349 of the outer core 307 engage
and are locked within both the catheter mating portion 313 and
implant mating portion 345, respectively. In this configuration,
the catheter 302, outer core 307, and implant 100 are fixed with
respect to each other, and can be advanced together through a
deployment sheath, such as a transseptal sheath (not illustrated
here) or other retractable sheath.
[0224] The inner core 305 is extended to contact and push against
the distal end 102 of the implant 100. Pushing on the distal
surface 126 at the distal end 102 with the inner core 305 while
holding the proximal end 104 in tension with the outer core 307
maintains the implant 100 in a reduced-diameter configuration. The
diameter-reduced implant 100 is advanced through the patient's
vasculature to a desired deployment site. At the deployment site,
the implant's 100 distal end 102 is positioned under visualization
at a desired location.
[0225] The outer core 307 is rotated with respect to the catheter
302 to cause the catheter cam 347 to align with an exit slot 355 in
the catheter mating portion 313. Because the catheter cam 347 and
implant cam 349 are offset from one another, alignment of the first
cam 347 with the catheter mating portion's 313 exit slot 355 does
not cause the second cam 349 to be aligned with the implant mating
portion's 345 exit slot 357. For example, in some embodiments, the
cams 347 and 349 are offset by about 15, 45, or 90 degrees from
each other.
[0226] The outer core 307 is then advanced distally with respect to
the catheter 302. The outer core 307 is now axially decoupled from
the catheter 302, but still coupled to the proximal end of the
implant 100 via the second cam 349-mating portion 345 engagement.
As the outer core 307 is moved distally, the proximal end 104 of
the implant 100 is also advanced distally. This causes the implant
100 to expand in a distal direction, e.g., while maintaining the
distal end 102 of the implant 100 in a substantially fixed position
with respect to the deployment site (e.g., the LAA 10, not pictured
here). In addition, as the outer core 307 is advanced distally with
respect to the catheter 302, the outer core 307 is also advanced
distally with respect to the inner core 305. This prevents distal
advancement of the outer core 307 from pushing the implant 100
deeper into the LAA 10, or out of the desired deployment
location.
[0227] When the implant 100 is fully expanded the outer core 307 is
disengaged, or decoupled from the implant 100 by rotating the
second cam 349 with respect to the implant 100. When the implant
cam 349, or a cam tab, is aligned with an exit slot 357 in the
implant mating portion 345, the outer core 307 can be retracted
proximally with respect to the implant 100 without substantially
affecting the implant's 100 deployment location or orientation. At
this point the outer core 307 is decoupled from both the catheter
302 and implant 100, and may withdrawn with the catheter 302 and
inner core 305 from the patient's vasculature.
[0228] In some embodiments the inner 305 and outer shafts 307 are
made from flexible hypotube. In other embodiments, the locking
mechanisms 309 and 311 are sometimes referred to as an implant key
or tip or as a catheter key or tip. The mating portion 313 of the
catheter 302 is sometimes referred to as the locking tip.
[0229] FIG. 21F illustrates another flexible implant delivery
system in accordance with yet another embodiment of the invention.
The delivery system 50 includes an implantable device 100 and a
release mechanism 200. The configuration described with respect to
FIG. 21F can be utilized and/or incorporated into any of the other
embodiments described herein.
[0230] The implantable device 100 is similar to all of the other
implantable devices described herein. The implantable device 100 is
configured to expand from a radially reduced configuration to a
radially expanded configuration. For example, in some embodiments,
the implantable device 100 is self expandable. The implantable
device 100 includes a plurality of struts that extend from the
implant's proximal end 104 to its distal end 102. A window, notch,
hole, or port, in the implant's proximal end 104 is configured to
releasably engage the release mechanism 200.
[0231] The release mechanism 200 includes a drive shaft 363, which
is coupled at its distal end to the proximal end of a flexible
recapture shaft 365. In one embodiment, the drive shaft 363 is made
from 0.025'' diameter tubing. In another embodiment, the flexible
recapture shaft 365 is made from 0.042'' outside diameter by
0.027'' inside diameter tubing. The distal end of the flexible
recapture shaft 365 is coupled to a threaded adapter 337. In one
embodiment, the recapture shaft 365 and adapter 337 are coupled
with a cross pin 338. For example, a 0.025'' cross pin 338 is
sometimes used. The distal end of the threaded adapter 337 is
coupled to a second flexible recapture shaft 367. In some
embodiments, a single flexible recapture shaft 365 is used, which
extends through the threaded adapter 337. The threaded adapter 337
includes a threaded portion 339 with threads along at least a
portion of its outside surface.
[0232] The driver 363, flexible recapture shafts 365 and 367, and
threaded adapter 337 are disposed within an outer shaft assembly
369. The outer shaft assembly 369 includes a braided shaft 371 that
is coupled at its distal end to a flexible torque shaft 375. In one
embodiment, the braided shaft 371 is the braided sock 392 described
above. In another embodiment, the braided shaft 371 has dimensions
of 0.084'' OD.times.0.055'' ID. In one embodiment, the flexible
torque shaft 375 is the braided sock 392 described above. In one
embodiment, the flexible torque shaft 375 has dimension of 0.083''
OD.times.0.072'' ID. The distal end of the flexible torque shaft
375 is coupled to a push screw disconnect 377, which in some
embodiments is the disconnect mount 236 described in greater detail
herein.
[0233] The push screw disconnect 377 has distally extending fingers
379 that have a larger diameter at their distal ends. The push
screw disconnect 377 also includes a threaded inside surface 381
configured to engage the threaded portion 339 of the threaded
adapter 337. The distal ends of the fingers 379 are configured to
engage the window 182 in the implant 100 and to hold the implant
100 with respect to the braided shaft 371 and flexible torque shaft
375. However, in one embodiment the fingers 379 are biased to flex
inward to release the implant 100. Therefore, an inner core
assembly 361, comprising the driver 363, flexible recapture shafts
365 and 367, and threaded adapter 337 are used to interfere with
inward movement of the fingers 379, and to hold the fingers 379
outward such that they continue to radially, coaxially engage the
implant 100.
[0234] To release the implant 100, the inner core assembly 361 is
rotated with respect to the push screw disconnect 377. The core
assembly 361 is rotated until it no longer engages the push screw
disconnect 377, at which point it is retracted proximally with
respect to the outer shaft assembly 369. Once the inner core
assembly 361 is retracted, the fingers 379 move radially and
concentrically inward to their biased position, thereby releasing
the implant 100. The implant 100 is released by removing the
concentric radial force provided by the outer core assembly 369.
Releasing the implant 100 in this manner does not cause the implant
100 to substantially jump, move, or otherwise change its
orientation with respect to the delivery system 50.
[0235] 3. Deployment Catheter and Deployment Handle
[0236] Referring again to FIG. 2, there is illustrated a block
diagram representing an implant delivery system 50 suitable for use
with any and all of the embodiments discussed herein. The implant
delivery system 50 includes an implant 100, an implant release and
recapture mechanism 200, a catheter system 300 and a deployment
handle 400. FIG. 2A illustrates one embodiment of an implant
delivery system 50 comprising particular examples of an implant
100, an implant release and recapture mechanism 200, a catheter
system 300 and a deployment handle 400.
[0237] Referring again to FIG. 11, there is schematically
illustrated a further embodiment of the present invention. An
adjustable implant delivery system 50 comprises generally a
catheter 302 for placing a detachable implant 100 within a body
cavity or lumen, as has been discussed. The catheter 302 comprises
an elongate flexible tubular body 306, extending between a proximal
end 308 and a distal end 310. The catheter is shown in highly
schematic form, for the purpose of illustrating the functional
aspects thereof. The catheter body will have a sufficient length
and diameter to permit percutaneous entry into the vascular system,
and transluminal advancement through the vascular system to the
desired deployment site. For example, in an embodiment intended for
access at the femoral vein and deployment within the left atrial
appendage, the catheter 302 will have a length within the range of
from about 50 cm to about 150 cm, and a diameter of generally no
more than about 15 French. Further dimensions and physical
characteristics of catheters for navigation to particular sites
within the body are well understood in the art and will not be
further described herein.
[0238] The tubular body 306 is further provided with a handle 402
generally on the proximal end 308 of the catheter 302. The handle
402 permits manipulation of the various aspects of the implant
delivery system 50, as will be discussed below. Handle 402 may be
manufactured in any of a variety of ways, typically by injection
molding or otherwise forming a handpiece for single-hand operation,
using materials and construction techniques well known in the
medical device arts.
[0239] In the embodiment illustrated in FIG. 14, or any other of
the deployment and/or removal catheters described herein, the
distal end 310 of the tubular body 306 may be provided with a zone
or point of enhanced lateral flexibility (indicated by the
sectional lines on the tube 306 at the distal end 310). This may be
desirable in order allow the implant to seat in the optimal
orientation within the left atrial appendage 10, and not be
restrained by a lack of flexibility in the tubular body 306. This
may be accomplished in any of a variety of ways, such as providing
the distal most one or two or three centimeters or more of the
tubular body 306 with a spring coil configuration. In this manner,
the distal end of the tubular body 306 will be sufficiently
flexible to allow the implant 100 to properly seat within the LAA
10. This distal flex zone on the tubular body 306 may be provided
in any of a variety of ways, such as by cutting a spiral slot in
the distal end of the tubular body 306 using laser cutting or other
cutting techniques. The components within the tubular body 306 such
as torque rod 340 may similarly be provided with a zone of enhanced
flexibility in the distal region of the tubular body 306.
[0240] FIG. 22 (which is similar to FIG. 2A) illustrates one
embodiment of an implant delivery system 50 comprising an operably
connected implant 100, an implant release and recapture mechanism
200, a catheter system 300 and a deployment handle 400. As shown in
FIG. 22, the embodied catheter system 300 comprises a peel-away
sheath 314, a recapture sheath 522, a deployment catheter 302, a
loading collar 323, a multi-lumen shaft 326, and an axially
moveable core 304, each described further below. The system 50 may
also include a transseptal sheath 520 (not illustrated here) that
is substantially coaxial and external to the other catheters. In
some embodiments, the transseptal sheath may be one of the other
catheters. The deployment handle 400 comprises a handle 402, a
control knob 408, a release knob 410, a proximal injection port 412
and a distal injection port 414. Injection ports 546, 548, as shown
in FIG. 22, preferably are provided in the delivery system 50 to
allow contrast injection proximally and distally of the implant 100
to facilitate in-vivo assessment of the positioning and seal
quality of the implant 100.
[0241] Referring again to FIG. 22, illustrated is an embodiment of
an implant delivery system 50. When an embodiment of the delivery
system 50 is assembled, a recapture sheath 522 is loaded over the
deployment catheter 302, distal to the handle 402. The recapture
sheath 522 is designed to allow recapture of the implant 100 prior
to its detachment or final release, such as described with respect
to retrieval catheter 502 above. Recapture petals or flares 510 may
be provided on the distal end 506 of the recapture sheath 522 to
cover the anchors 118 of the implant 100 during retrieval into the
transseptal sheath 520, as described above with respect to FIGS.
15C-15E, and further below. A Touhy-Borst adapter or valve 530 may
be attached to the proximal end 524 of the recapture sheath 522.
The recapture sheath 522 comprises a radiopaque marker 528 on its
distal end 526 near the recapture flares 510. The recapture sheath
522 comprises a recapture sheath injection port 529 for delivering
fluid proximal the implant 100.
[0242] An embodiment of the peel-away sheath 314 is provided over a
portion of the recapture sheath 522, between Touhy-Borst valve 530
and recapture flares 510. The peel-away sheath 314 is used to
introduce a catheter 302 into a transseptal sheath 520 (not
illustrated). As shown in FIG. 22, an embodiment of the peel-away
sheath 314 comprises a locking collar 315, a peel-away section 316,
and a reinforced section 317. The locking collar can be unlocked
relative to peel-away section 316, and may include a threaded hub
318 that releasably engages tabs 319 of the peel-away section
316.
[0243] An embodiment of the loading collar 323 is located over a
portion of the peel-away sheath 314 and a portion of the recapture
sheath 522 with its proximal end being located over the peel-away
sheath 314 at its distal end loaded over recapture sheath 522. The
loading collar 323 can accommodate loading a collapsed implant 100
into the peel-away sheath 314 as described below. As shown in FIG.
17, an embodiment of the loading collar 323 comprises a first end
portion 324 adapted to receive and extend over a collapsed implant
100, and a second end portion 325 configured to guide the collapsed
implant 100 into the peel-away sheath 314. The loading collar 323
may be made of stainless steel.
[0244] In order to assemble an embodiment of the delivery system
50, the axially movable core 304 and control line 312 are fed into
the multi-lumen shaft 326 of the deployment catheter 302. The
multi-lumen shaft 326 is then coupled with components of the
deployment handle 400 and the injection port components 412, 414.
The peel-away sheath 314 and the loading collar 323 are slid onto
the recapture sheath 522, and the recapture sheath 522 is slid onto
the deployment catheter 302. The implant 100 is then loaded on an
end of the axially movable core 304 and coupled with the control
line 312. In one embodiment, the implant 100 is loaded on an end of
the axially movable core 304 by screwing the axially movable core
304 into the threaded portion 246 of a disconnect mount 236 (not
illustrated here). The control knob 408 and outer casing of the
deployment handle 400 are then coupled with the system.
[0245] In an embodiment of the deployment catheter system 300, a
catheter 302 is used in connection with a transseptal sheath 520
(not illustrated here, but see FIG. 25) to advance the implant 100
for deployment in a patient. The transseptal sheath 520 is a
tubular device that in one embodiment can be advanced over a
guidewire (not shown) for accessing the LAA 10 of a patient's heart
5. In some embodiments the transseptal sheath 520 may also serve as
one of the other disclosed catheters described herein. Transseptal
sheath 520 in some embodiments has a permanent bend or a
controllable bend. A hemostasis valve (not illustrated) is provided
at the proximal end of transseptal sheath. A fluid injection port
is also provided at the proximal end to delivery fluid such as
contrast media through the transseptal sheath. Systems and methods
for implanting the device 100 in the LAA 10 are described further
below.
[0246] One embodiment of a multi-lumen shaft 326 may comprise a
four-lumen shaft as illustrated in FIG. 22A. The multi-lumen shaft
326 comprises a core lumen 328 for holding an axially moveable core
304, a control line lumen 330 and two proximal injection lumens 332
in communication with proximal injection port 412. In some
embodiments, the axially moveable core 304 is the implant
activation shaft 334, discussed in greater detail above.
[0247] An axially moveable core 304 preferably extends from the
deployment handle 400 through the core lumen 328 of the catheter
302 and couples the implant 100 of the delivery system 50. A
control line 312 (referred to previously as a pull wire 312)
preferably extends through the control line lumen 330 and
preferably couples a proximal hub 104 of the implant 100 to the
deployment handle control knob 408, allowing for implant 100
expansion and collapse. The control line 312 preferably extends
around a portion of the axially movable core 304 near the proximal
hub 104 of the implant 100, and is coupled to the implant 100 by
crosspin 146, as described above.
[0248] Referring to FIG. 23, one embodiment of the catheter system
300 preferably comprises a flexible catheter section 362 at its
distal end, which in some embodiments is a spiral cut tubular
section housed in a polymer sleeve 366. The flexible catheter
section 362 may be coupled to a distal end of a multi-lumen shaft
326.
[0249] As shown in FIGS. 24 and 24A, one embodiment of the axially
moveable core 304 preferably includes a hollow proximal shaft 368
and a hollow distal shaft 370 with a flexible hollow core section
372 therebetween, all co-axially aligned and connected. In one
embodiment, the proximal end of the distal shaft 370 is attached to
the distal end of the flexible core section 372, and the proximal
end of the flexible core section 372 is attached to the distal end
of the proximal shaft 368. In some embodiments, the flexible core
section 372 has a spring coil section 374 housed in a polymer
sleeve 376, the spring coil section 374 preferably coupled with the
shafts 368 and 370 on first and second ends 378 and 380,
respectively. In another embodiment an injection tube 373 with a
lumen is provided, through which contrast fluid may be ejected out
of the distal end of the implant actuation shaft 334 and into the
implant 100. This is useful in assessing implant seal against the
ostium or inside wall of the left atrial appendage. The injection
tube 373 has been prototyped in low durometer (flexible) PEBAX and
provides a soft segment transition over the distal-most 10 cm of
the delivery catheter 302 or within a flexible core section 372.
The injection tube 373 may be connected to other tubes such as a
lock tube 234 (as discussed relating to FIGS. 17-20) but is not
used to torque or apply rotational forces to the tube.
[0250] The axially moveable core 304 preferably is disposed within
the deployment catheter 302 such that the flexible core section 372
may be linearly co-located with the flexible catheter section 362
at a distal portion 382 of the catheter system 300 during
appropriate times during a procedure, as shown in FIG. 23. When the
flexible core section 372 is aligned and linearly co-located with
the flexible catheter section 362, the sections preferably
cooperate to form a delivery system flexible segment 384. As shown
in FIGS. 22 and 23, the delivery system flexible segment 384
preferably is located toward a distal portion 382 of the catheter
system 300.
[0251] In one embodiment, shown in FIG. 24, the distal shaft 370,
flexible core section 372, and proximal shaft 368 are attached by
welding. Small windows 386 may be provided to allow welding
materials to flow between the shafts 564, 576 and 578 and provide
stronger bonding therebetween. In another embodiment, solder, glue,
or press-fitting is used to attach shafts 564, 576, and 578 to one
another, as is well known to those of skill in the art. In another
embodiment, the shafts 564, 576 and 578 are formed from a single
tube, for example, a laser-cut tube. In other embodiments, more
than one tube may be used to form each of the shafts 564, 576 and
578. For example, FIG. 24 illustrates proximal shaft 368 comprising
two tubes connected by welding such as described above.
[0252] Referring again to FIG. 24A, distal contrast media
preferably can be injected through a lumen 388 in the shafts 576
and 578 for determining the placement of the implant 100. This
lumen 388 may be in fluid communication with distal injection port
414, shown in FIG. 22. The distal shaft 370 preferably comprises a
mating surface 390 and a radiopaque marker 360, such as described
above. In one embodiment, the mating surface 390 is a threaded
surface. The distal shaft 370 preferably is releasably coupled to
the implant 100, such as described above.
[0253] FIG. 25 illustrates an embodiment of a puzzle lock profile
600 that may be used with any of the embodiments of the implant
delivery system 50 described herein in order to increase
flexibility. As discussed above, some of the embodiments deliver an
implant 100 to the LAA 10 in an orientation and under a loading
condition that approximates the final released state of the implant
100. This reduces bias and moment arms that can cause the implant
100 to deform, move, jump, or change orientation when the implant
100 is released from the implant delivery system 50. Component
rigidity and off-axis loading can contribute to these undesirable
effects. An elongate tube having a strong, flexible, cut wall
pattern such as the puzzle lock profile 600 can improve system
flexibility and reduce unwanted loading conditions.
[0254] FIGS. 25A-25C illustrate a puzzle lock profile 600 in
accordance with an embodiment. The puzzle lock profile 600 can be
used to create highly flexible materials such as tubing with push,
pull, and torque capabilities. The puzzle lock profile 600 can be
used to transmit axial loads and rotational torque loads while
minimizing bending loads through its flexibility. As illustrated,
one embodiment of the puzzle lock profile 600 comprises a cut
through a tube or a layer of material using a laser or some other
similar manufacturing means known in the art. Referring to FIG.
25B, illustrated is a tube 605 with a longitudinal axis 610, a
diametric axis 620, and a puzzle lock profile 600 cut into it. The
tube 605 can be any tube or shaft discussed herein. The
longitudinal axis 610 runs along the general axis in the lumen of a
tube or through the center of a solid tube when that tube is
straight. The diametric axis 620 lies in a plane that is
perpendicular to the longitudinal axis 610 and runs along a
diameter of the tube 605.
[0255] In some embodiments, a cut 635 may start at either the
proximal or distal end of the tube 605. In other embodiments, a cut
635 may start at an offset length 630 from an end of a tube 605.
The offset 630 may provide structural support to the ends of the
tube or may represent an uncut tubing length prior to a puzzle cut
region in a tube. A corresponding offset 630 may exist at the other
end of the tube 605, and in some embodiments there may be a
plurality of regions in a tube 605, alternating between puzzle lock
profile 600 regions and uncut tubing or offset 630 regions.
[0256] Referring to FIG. 25C, a puzzle lock profile 600 is
presented in close up of a tube 605. FIG. 25C may also be
considered a view of a tube 605 that has been sliced longitudinally
and spread into a flat planar surface. In this view, a cut 635 can
have a cut axis 640 which runs along the length of the cut 635. As
illustrated, the weaving cut 635 follows a repeating pattern that
is symmetric around the cut axis 640. In one embodiment a tube 605
has a number of generally parallel cut axes 640, 650, 660, and 670.
Additional cut axes may continue along a length of the tube 605
(not illustrated). In one embodiment, cut axes 640, 650, 660, and
670 may be parts of a single continuous cut that traverses external
surface of a tube 605, similar to a spiral. In another embodiment,
cut axis 640 and cut axis 650 may be two parallel cut axes that are
offset from each other, creating two interlaced parallel spiral
cuts along the tube 605. In one embodiment, the two spiral cuts
start 180 degrees from each other in a plane perpendicular to the
longitudinal axis 610 of the tube 605 to create two symmetric
spiral cuts and two helical tube surfaces. The two starting points
may be located on the diametric axis 620 at intersection points
with the external surface of the tube 605. In this embodiment, a
first cut 635 moves along a cut axis 640 which is contiguous with
cut axis 660, and a second cut 636 is contiguous with cut 670. In
other embodiments, there may be two, three, four, or a plurality of
cuts, such as cut 635, cut 636, cut 637 and cut 638, that create
parallel spiral cuts along the tube 605 with cut axes 640, 650,
660, and 670, respectively, which can create either symmetric or
non-symmetric spiral cuts and helical tube surfaces along the tube
605.
[0257] Referring to FIG. 25C, illustrated is an embodiment of a
puzzle lock profile 600 with a single cut 635 that extends along
cut axes 640, 650, 660, and 670 each time the cut 635 wraps around
the outer circumference of a tube 605. The cut 635 extends
generally around the circumference of the tube 605 and follows a
continuous repeating pattern which is inclined at a slight angle
.alpha. from a diametric axis 620 to a longitudinal axis 610 of the
tube 605. Each of the cut axes 640, 650, 660, and 670 are parallel
to each other with a planar cut axis that can be drawn along the
general direction of the cut 635. In one embodiment, a cut 635 is
oriented to follow a cut axis 640 with an angle .alpha. of zero
degrees, the cut axis 640 being parallel to the diametric axis 620
and perpendicular to the longitudinal axis 610 of the tube 605,
resulting in a cut that would traverse the circumference of the
tube 605 and return to the same location as its starting point,
thereby creating a series of interlocked rings with multiple cuts.
In another embodiment, angle .alpha. may be anywhere in a range of
0 to 90 degrees, where in some embodiments angle .alpha. may be
about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45,
50, 60, 65, 70, 75, 80, 85, or 90 degrees. In the illustrated
embodiment in FIG. 25C, angle .alpha. is in the range of about 5-7
degrees.
[0258] Along a given cut axis 640, the cut 635 may run along a
pattern that alternates on either side of the cut axis 640 and that
runs parallel to the cut axis 640 at a distance 642 and a distance
643. In some embodiments, distance 642 equals distance 643. As a
cut 635 alternates on either side of the cut axis 640 the pattern
cuts a length 646 along a cut axis 640 when the cut 635 is on the
distance 643 from the cut axis 640, and a length 647 along a cut
axis 640 when the cut 635 is on the distance 642 from the cut axis
640. In some embodiments, length 646 equals length 647. As a cut
635 runs along a pattern at a distance 643, it enters a bend toward
the cut axis 640. The bend has a radius 644 which is on the order
of half of the distance 643. As the cut 635 approaches the cut axis
640 the bend reaches an inflection point and changes direction,
creating a bend with a radius 645 which is on the order of half of
the distance 642. In some embodiments, radius 644 equals radius
645. These bends create a set of interlocking projections that keep
the tube engaged to transmit axial loads and rotational loads,
about the longitudinal axis 610 while providing flexibility in the
tube 605 to reduce bending moments.
[0259] The dimensions of a cut 635 with respect to a cut axis 640
depends on the desired push, pull, and torque characteristics of a
given tube 605, and may further depend on tube 605 thickness,
diameter, length, and material. In some embodiments, the tube 605
is made of metal, stainless steel, hypodermic materials, nickel
titanium, plastic, polymers, silver, or radiopaque visualization
materials. Angles and lengths and various other dimensions depend
on the number of parallel cuts that may be desired as well.
Embodiments of the puzzle lock profile 600, as illustrated in FIGS.
25 and 25A-25C, may be used in the material of an implant actuation
shaft 334, a lock tube 234, a catheter body 302, a retrieval
catheter 502, a transeptal sheath 520, a catheter system 300, a
retrieval catheter system 500, or any component of an implant
delivery system 50, as discussed herein. The puzzle-interlocking
features 338 illustrated provide super flexibility of the various
tubes while maintaining push, pull and torque transmission
capabilities. Any of the puzzle-interlocking profile 600 tubes can
be covered with a thin silicone tubing to provide a seal over the
interlocking portions of the tube to allow for transport of
contrast or other fluids within the lumen of the tubes. In some
embodiments, portions of tubes (such as a flexible core section 372
or a flexible segment 384 as illustrated in FIG. 24) which require
greater flexibility can use the puzzle lock profile 600 which are
attachable to other embodiments of the respective tube. In other
embodiments, the entire tube or component can be constructed using
a puzzle lock profile 600.
[0260] In one embodiment, a puzzle lock profile 600 is incorporated
into an implant actuation shaft 334. Previous embodiments of
implant actuation shafts 334 have been described in terms of an
axial moveable core 304 and a torque rod 340, as discussed above
relating to at least FIGS. 17-21. The implant actuation shaft 334
is generally a tubular structure for imparting a distal force on
the distal end 102 of the implant 100. In various embodiments, the
implant actuation shaft 334 can be a hypodermic or a metallic tube.
In addition, the implant actuation shaft 334 can be cut (e.g.,
laser cut) to have a spiral or puzzle-lock wall profile 600. One
embodiment of a puzzle lock profile 600 is shown in FIG. 25. A
spiral cut has little resistance to bending, is capable of applying
limited compression and can be torqued in one direction. The
puzzle-lock profile 600 cut has these same properties but is also
capable of applying tension and torque in both directions. The
puzzle lock 338 is generally screwed in and out of the catheter
system 300 in both clockwise and counter-clockwise directions.
Since both cuts generally are not able to apply bending moment,
they are both advantageously very flexible. Embodiments of
puzzle-lock tubes are disclosed in U.S. Pat. No. 6,273,876, filed
Nov. 3, 1998, which is incorporated by reference herein.
[0261] Referring back to FIGS. 21A-21C, there is illustrated an
embodiment of a flexible sock 392, such as a metallic mesh sock 392
(e.g., made from nickel titanium, or NITINOL), which partially
covers at least a portion of an implant actuation shaft 334 and a
slide tube 394. The implant actuation shaft 334 works with the sock
392 to collapse the implant. As discussed above, the memory metal
properties of the implant 100 cause its natural state to be open,
or radially expanded to an expanded-diameter configuration. Distal
force is applied to override the natural state and place the
implant 100 in tension in order to reduce the implant 100 to its
reduced-diameter configuration. A small moment arm associated or
combined with the distal force can cause the delivery catheter 302
to bend. This in turn can cause the implant 100 to shift and change
its spatial orientation, depending upon the amount of force and/or
the amount the implant 100 is collapsed. A concentric, 360.degree.
application of tension concentric to the compression force
delivering implant actuation shaft 334 helps achieve non-biased
expansion of the implant 100. The tension member in the form of a
sock 392 avoids applying bending moment, as previously discussed.
It also avoids applying compression. In order for the left atrial
appendage (not illustrated here) to naturally assert its influence
on the implant 100 and for the implant 100 to be properly seated
within the left atrial appendage, once the tension has been
released, it is advantageous if no additional expansion loads are
transmitted from the delivery catheter 302 to the implant 100. If
there were, the delivery catheter 302 could falsely bias the
implant 100 into an exaggerated or over-expanded expanded state,
which would not represent the final release conditions. In such
cases the expansion force of the implant 100 could override the
compression forces provided by the left atrial appendage.
[0262] The sock 392, which can be a braided, multi-stranded nickel
titanium tube, is preferably used to help achieve concentric
application of tension to the implant 100. Prototypes have shown
tensile forces exceeding two times those used to collapse the
implant 100; no bending resistance; and no compression load
transfer over the first 50% of axial strain (e.g., the sock 392
flexibly collapses to a point, as illustrated in FIG. 21C). The
sock 392 can provide tension forces to the proximal end 104 of the
implant 100 via the disconnect flex fingers 238 described above.
The sock 392 can be attached to the delivery catheter 302 and
disconnect mount 236 using any method known to those of skill in
the art, including adhesive, welds, bonds, mechanical links, pins,
etc. In one embodiment, LOCTITE adhesive is used to bond the
proximal end of the sock 392 to the distal end of the delivery
catheter 302. In other embodiments, the sock 392 is trapped with a
laser weld or swaged ring. The sock 392 can also be re-flowed
directly into the delivery catheter 302 outer lumen or it can be an
extension of a braid that can be provided in the delivery catheter
302. The ability of the sock 392 to "spring back," or return to its
initial state without taking a permanent set helps maintain
consistent expansion and collapse properties during the implant 100
deployment and recapture process. The super-elastic properties of
NITINOL are well-suited for use as the sock 392. In addition, a
stainless steel braid will take a set and create compression bias
as well. In one embodiment, the sock 392 may use aspects of a
puzzle lock profile 600 as described above.
[0263] In some embodiments, a slide tube 394 is provided inside the
sock 392 and outside an implant actuation shaft 334. The slide tube
394 may be used to prevent the sock 392 from binding on a implant
actuation shaft 334 or act as a stop in limiting axial motion of
the implant actuation shaft 334. The slide tube 394 may slide
freely with respect to the implant actuation shaft 334 or the
collar 394 may be attached to the implant actuation shaft 334 in
any number of ways know to the art. In one embodiment, the slide
tube 394 may be an integral part of the implant actuation shaft
334. As shown in FIGS. 21A-21C, an embodiment of an implant
delivery system 50 includes a slide tube 394. A handle (not
illustrated here) provides proximal tension, a sock 392 necks down
onto the slide tube 394 and pulls a proximal end 104 of an implant
100 away from its distal end 102. The distal end 102 is held
"stationary" by an implant actuation shaft 334. As the sock 392
pulls the proximal end 104 proximally with respect to the distal
end 102, the implant 100 is reduced in diameter. As the tension on
the proximal end 104 is released the proximal end 104 moves
distally towards the distal end 102, and the implant's diameter
expands. A control on the handle controls tension on the proximal
end 104.
[0264] B. Configurations and Methods of Use of an Implant Delivery
System
[0265] Referring to FIG. 6, illustrated is an embodiment of an
implant delivery system 50. The system and method allows for access
and assessment of the LAA 10. In one embodiment, a guidewire (not
shown) is used to access the superior vena cava through groin
access. A transseptal sheath 520 is advanced over the guidewire and
into the superior vena cava. The guidewire is removed and replaced
with a transseptal needle (not shown). The transseptal sheath 520
preferably is retracted inferiorly so that a bend in the
transseptal sheath directs the distal tip of the transseptal sheath
toward the fossa ovalis. The needle is advanced to puncture the
fossa ovalis. The transseptal sheath 520 is advanced to establish
access to the LAA 10 and the needle is retracted. Further details
or disclosure are provided above and in copending U.S. patent
application Ser. No. 09/435,562 and U.S. Pat. No. 7,044,134, issued
May 16, 2006, the entireties of which are hereby incorporated by
reference.
[0266] After preparing a transseptal sheath 520 for LAA 10 access,
the size of the neck diameter and morphology of the LAA 10
preferably is determined by advancing the transseptal sheath 520 to
the distal portion of the LAA 10 and injecting contrast media to
obtain an initial left atrial appendogram. The neck diameter
preferably is measured approximately 5 mm in from the ostium of the
LAA 10 at end diastole.
[0267] Referring to FIG. 22, illustrated is an embodiment of a
system and method that allows for selection and preparation of a
deployment system 50. A deployment system 50 preferably comprises
an implant 100 of an appropriate size for placement in a patient.
Initially, the implant 100 preferably is in an expanded
configuration, with an implant release and recapture mechanism 200
engaging the implant 100, as described above. The recapture sheath
522 preferably is positioned so it covers and supports the flexible
segment 384 of the delivery system 50, wherein the flexible
catheter section 362 of deployment catheter 302 and flexible core
section 372 of axially moveable core 304 are aligned. The
Touhy-Borst valve 530 preferably is tightened over the deployment
catheter 302 to prevent relative movement between recapture sheath
522 and deployment catheter 302. The loading collar 323 and
peel-away sheath 314 preferably are positioned so they are at the
base of the recapture flares 510, proximal thereto.
[0268] In one embodiment, the delivery system 50 is loaded by
rotating the control knob 408 counterclockwise until the implant
100 is fully collapsed. Preferably, at least a portion of the
control line 312 is coupled with the control knob 408 such that
rotation of the control knob 408 retracts at least a portion of the
control line 312. In an embodiment, the rotation of the control
knob 408 is in the counterclockwise direction to retract at least a
portion of the control line 312. Retraction of the control line 312
preferably places tension on the proximal hub 104 of the implant
100, because a portion of the control line 312 preferably is
coupled with the proximal hub 104 by a pin 146. While the distal
portion of the axially moveable core 304 applies a distal force to
distal hub 108 of the implant 100, tension in the control line 312
preferably causes the proximal hub 104 of the implant 100 to move
proximally relative the axially moveable core 304, thereby
collapsing the implant 100.
[0269] In another embodiment, the delivery system 50 is loaded with
an implant 100 connected to an implant release and recapture
mechanism 200, which is connected to a catheter system 300, which
is connected to a deployment handle 400. A disconnect mount
interface 180 on the proximal end 104 of the implant 100 is
connected to a disconnect mount 236 on a catheter system 300 which
can provide releasable concentric loading to the implant 100 as
described above. In one embodiment, the concentric loading is
concentric tension. In one embodiment the concentric loading is
provided by a disconnect mount interface 180 with a finger
interface 182 which interacts with a flexible finger 238 on the
disconnect mount 236. Embodiments of the finger interface 182 may
be in the form of a protruding finger, an interlocking feature, a
groove, a slot, a window, or other similar features for releasably
holding a disconnect mount 236 flexible finger 238. In one
embodiment the flexible finger 238 is engaged with the finger
interface 182 and a lock tube 234 is slid into place to secure the
engagement between the flexible finger 238 is engaged with the
finger interface 182. In some embodiments, the lock tube 234 may be
rotated to threadably engage with a catheter 302 to lock in place.
In other embodiments no lock tube 234 is necessary.
[0270] An implant actuation shaft 334 may be extended distally
through the catheter 302 into the implant 100 to radially-reduce
the implant 100 by placing the implant 100 in tension. The implant
actuation shaft 334 may be advanced distally by axial sliding,
rotational engagement with a threaded surface 336, or a combination
of both. In one embodiment, the implant actuation shaft 334 has a
threaded portion 336 that threadably engages with a hub 236 to lock
the implant 100 in a radially reduced configuration, as described
above. In this embodiment, the implant 100 may be loaded by sliding
the implant actuation shaft 334 distally until its threaded portion
336 comes into contact the hub 236, and then rotating the control
knob 408 counterclockwise to threadably engage the threaded portion
336 and the hub 236 until the implant 100 is fully collapsed.
[0271] The diameter of the implant 100 preferably is reduced to
approximately 1/3.sup.rd or less of its original diameter when
collapsed. The loading collar 323 and peel-away sheath 314 are then
advanced distally over the flares 510 and implant 100 until the
distal tip of the implant 100 is aligned with the distal end of the
peel-away sheath 314 and the distal end of the loading collar is
about 1.5 cm from the distal tip of the implant 100. At this point,
the flares 510 partially cover the implant. The loading collar 323
preferably is removed and discarded.
[0272] With the implant 100 partially within the recapture sheath
522 and retracted within the peel-away sheath 314, the entire
system preferably is flushed with sterile heparinized saline after
attaching stopcocks to the recapture sheath injection port 529, the
proximal injection port 412 and distal injection port 414 of the
delivery system 50. The recapture sheath 522 and the Touhy-Borst
valve 530 are first thoroughly flushed through port 529. Then the
distal injection port 414 and the proximal injection port 412 of
the deployment handle 400 are preferably flushed through. The
distal injection port 414 is in fluid communication with lumen 388
of axially moveable core 304 (as illustrated in FIG. 24A), and
proximal injection port 412 is in fluid communication with
injection lumens 332 of multilumen shaft 326. The transseptal
sheath 520 placement preferably is reconfirmed using fluoroscopy
and contrast media injection.
[0273] The delivery system 50, as described above, with implant 100
inserted therein, preferably is then inserted into the proximal end
of a transseptal sheath 520 (as shown in FIG. 6). To avoid
introducing air into the transseptal sheath 520 during insertion of
the delivery system 50, a continual, slow flush of sterile
heparinized saline preferably is applied through the proximal
injection port 412 of the deployment handle 400 to the distal end
of the deployment catheter 302 until the tip of the peel-away
sheath 314 has been inserted into, and stops in, the hemostatic
valve of the transseptal sheath 520. Preferably, the distal tip of
the peel-away sheath 314 is inserted approximately 5 mm relative to
the proximal end of the transseptal sheath 520.
[0274] Under fluoroscopy, the recapture sheath 522 and deployment
catheter 302 preferably are advanced, relative to the peel-away
sheath 314, approximately 20-30 cm from the proximal end of the
transseptal sheath 520, and the system 50 preferably is evaluated
for trapped air. The peel-away sheath 314 is preferably not
advanced into the transseptal sheath 520 due to a hemostasis valve
(not illustrated) on the transseptal sheath 520 blocking its
passage. If air is present in the system 50, it may be removed by
aspirating through the distal injection port 414, recapture sheath
injection port 529, or proximal injection port 412. If air cannot
be aspirated, the deployment catheter 302 and recapture sheath 522
preferably are moved proximally and the delivery system 50
preferably is removed from the transseptal sheath 520. All air
preferably is aspirated and the flushing/introduction procedure
preferably is repeated.
[0275] The peel-away sheath 314 preferably is manually slid
proximally to the proximal end 524 of the recapture sheath 522. The
Touhy-Borst valve 530 preferably is loosened and the deployment
catheter 302 preferably is advanced distally relative to the
recapture sheath 522 until the deployment handle 400 is within
about 2 cm of the Touhy-Borst valve 530 of the recapture sheath
522. This causes the implant 100 to be advanced distally within the
transseptal sheath 520 such that the recapture sheath 522 no longer
covers the implant 100 or the flexible section 558. The Touhy-Borst
valve 530 preferably is tightened to secure the deployment catheter
302 to fix relative movement between the deployment catheter 302
and recapture sheath 522.
[0276] Under fluoroscopy, the implant 100 preferably is advanced to
the tip of the transseptal sheath 520 by distal movement of the
delivery catheter 302. The distal hub 108 of implant 100 preferably
is aligned with a transseptal sheath tip radiopaque marker 521 (see
FIG. 6). Under fluoroscopy, the sheath 520 positioning within the
LAA 10 preferably is confirmed with a distal contrast media
injection.
[0277] The position of the implant 100 preferably is maintained by
holding the deployment handle 400 stable. The transseptal sheath
520 preferably is withdrawn proximally until its tip radiopaque
marker 521 is aligned with the distal end of the deployment
catheter flexible segment 384. In some embodiments, the transseptal
sheath 520 is withdrawn proximally until its tip radiopaque marker
521 is aligned with the distal end of the mesh sock 392. In other
embodiments, the transseptal sheath 520 is withdrawn proximally
until its tip radiopaque marker 521 is aligned with the proximal
end of the mesh sock 392, or at a location between the proximal and
distal ends of the mesh sock 392. This preferably exposes the
implant 100.
[0278] In one embodiment, under fluoroscopy, the implant 100
preferably is expanded by rotating the control knob 408 clockwise
until it stops. Rotating the control knob 408 preferably releases
tension on the control line 312, preferably allowing the implant
100 to expand. The implant 100 preferably is self-expanding. After
expansion, any tension on the LAA 10 preferably is removed by
carefully retracting the deployment handle 400 under fluoroscopy
until the radiopaque marker 360 (see FIG. 24) on the axially
movable core 304 moves proximally approximately 1-2 mm in the guide
tube 130 (see FIG. 11). In an embodiment, the position of the
implant 100 relative the LAA 10 preferably is not altered because
the axially movable core 304 preferably is coupled with an axially
decoupled implant release and recapture mechanism 200, as is shown
in an embodiment illustrated in FIGS. 16A and 16B, which allows for
relative movement between the implant 100 and the axially movable
core 304. The implant release and recapture mechanism 200
preferably allows for the distal portion of the axially movable
core 304 to be slightly retracted proximally from the distal end
102 of the implant 100, thereby removing any axial tension that may
be acting on the implant 100 through the axially movable core 304.
The axial moveable core 304 radiopaque marker 360 preferably is
about 1-2 mm proximal from the implant 100 distal end 102, and the
transseptal sheath 520 tip preferably is about 2-3 mm proximal from
the implant proximal end 104, thereby indicating a neutral
position.
[0279] In another embodiment, the delivery system 50 comprises an
implant 100 connected to an implant release and recapture mechanism
200, which is connected to a catheter system 300, which is
connected to a deployment handle 400. A disconnect mount interface
180 on the proximal end 104 of the implant 100 is connected to a
disconnect mount 236 on a catheter system 300 which provides
releasable concentric loading to the implant 100 as described
above. In one embodiment, the concentric loading is concentric
tension. In one embodiment the concentric loading is provided by a
disconnect mount interface 180 with a finger interface 182 which
interacts with a flexible finger 238 on the disconnect mount
236.
[0280] As discussed above, in some embodiments the order of the
following steps may be accomplished in the following sequence, or
in reverse sequence, or in a combination of repeated steps in order
to have the implant 100 expand and release an implant 100 in a
distal, proximal, or relatively axially-stationary direction.
[0281] In one embodiment, the implant actuation shaft 334 may be
retracted proximally through the catheter 302 through the implant
100 to radially-expand the implant 100 by removing the tensile load
from distal end 102 of the implant 100. The implant actuation shaft
334 may be retracted proximally by axial sliding, rotational
engagement with a threaded surface 336, or a combination of both.
In one embodiment, the implant actuation shaft 334 has a threaded
portion 336 that threadably engages with a hub 236 to lock the
implant 100 in a radially reduced configuration, as described
above. In this embodiment, the implant 100 may be unloaded rotating
the control knob 408 until the hub 236 and implant actuation shaft
334 threaded portion 336 detach, and by sliding the implant
actuation shaft 334 proximally. If the implant actuation shaft 334
is moved proximally and the proximal end 104 of the implant 100
remains relatively stationary with respect to the catheter body
302, the implant 100 will expand within the LAA 10 in a generally
proximal direction, as described above.
[0282] In one embodiment a disconnect mount interface 180 on the
proximal end 104 of the implant 100 is connected to a disconnect
mount 236 on a catheter system 300 which can provide releasable
concentric loading to the implant 100 as described above. In one
embodiment, the concentric loading is concentric tension. In one
embodiment the concentric loading is provided by a disconnect mount
interface 180 with a finger interface 182 which interacts with a
flexible finger 238 on the disconnect mount 236. The flexible
finger 238 is engaged with the finger interface 182 and a lock tube
234 secures the engagement between the flexible finger 238 and the
finger interface 182. In one embodiment, the implant 100 may be
expanded by allowing the catheter 302 to advance distally while the
implant actuation shaft 334 remains stationary at the distal end
102 of the implant 100 as is illustrated in FIGS. 18A and 18B. In
another embodiment, a mesh sock 392 in a compressed state may be
released to allow the proximal end 104 of the implant 100 to move
distally while the implant actuation shaft 334 remains stationary
at the distal end 102 of the implant 100. In another embodiment,
the implant 100 may be expanded by removing the lock tube 234 from
the flexible finger 238 and finger interface 182. In some
embodiments, the lock tube 234 may be rotated to threadably
disengage from a catheter 302 to unlock the lock tube 234. In other
embodiments no lock tube 234 is necessary. When the implant
actuation shaft 334 remains extended and attached to the proximal
end 104 of the implant 100 and the fingers 238 are released from
the finger interfaces 182, the implant 100 will expand within the
LAA 10 in a generally distal direction, as described above.
[0283] The implant 100 preferably is self-expanding. After
expansion, any tension on the LAA 10 preferably is removed by
carefully retracting the deployment handle 400 under fluoroscopy
until the radiopaque marker 360 (see FIG. 24) on the axially
movable core 304 moves proximally approximately 1-2 mm in the guide
tube 130 (see FIG. 11). In an embodiment, the position of the
implant 100 relative the LAA 10 preferably is not altered because
the implant actuation shaft 334 preferably is coupled with an
axially decoupled implant release and recapture mechanism 200, as
is shown in an embodiment illustrated in FIGS. 16A and 16B, which
allows for relative movement between the implant 100 and the
implant actuation shaft 334. The implant release and recapture
mechanism 200 preferably allows for the distal portion of the
axially movable core 304 to be slightly retracted proximally from
the distal end 102 of the implant 100, thereby removing any axial
tension that may be acting on the implant 100 through the axially
movable core 304. The axial moveable core 304 radiopaque marker 360
preferably is about 1-2 mm proximal from the implant 100 distal end
102, and the transseptal sheath 520 tip preferably is about 2-3 mm
proximal from the implant proximal end 104, thereby indicating a
neutral position.
[0284] Under fluoroscopy, the expanded diameter (O in FIG. 6) of
the implant 100 preferably is measured in at least two views to
assess the position of the implant within the LAA 10. The measured
implant diameter O preferably is compared to the maximum expanded
diameter.
[0285] Preferably, the labeled proximal 412 and distal injection
ports 414, of the deployment handle 400 shown in FIG. 22, correlate
with the proximal and distal contrast media injections. The
proximal contrast media injections are delivered through the
delivery catheter lumen 332 to a location proximal to the implant
100. The distal contrast media injections are delivered through the
axially movable core 304 to a location distal to the implant 100.
Proximal contrast media injections preferably are completed in two
views. If the injection rate is insufficient, the recapture sheath
injection port 529 may be used independently or in conjunction with
the proximal injection port 412 to deliver fluid to a location
proximal to the implant 100.
[0286] If satisfactory results are seen, any transverse tension on
the LAA 10 preferably is released by exposing the flexible segment
384 of the delivery system 50. The flexible catheter section 362
and the flexible core section 372 preferably are linearly
co-located to cooperate as the flexible segment 384 of the delivery
system 50. This preferably is accomplished by retracting the
transseptal sheath 520 proximally approximately 2 cm to expose the
flexible segment. By exposing the flexible segment 384, the
flexible segment 384 preferably will flex to allow the implant 100
to sit within the LAA 10 free from transverse forces that may be
created, for example, by contractions of the heart acting against
the transseptal sheath 520 or deployment catheter 302. Once the
flexible segment 384 is exposed, distal contrast media injections
preferably are completed in at least two views to verify proper
positioning of the implant 100. A flush of saline preferably is
used as needed between injections to clear the contrast media from
the LAA 10. Following the contrast media injections, the
transseptal sheath 520 preferably is advanced distally to cover the
flexible segment 384.
[0287] In another embodiment, any transverse tension on the LAA 10
preferably is released by a mesh sock 392 and a proximal retraction
of an implant actuation shaft 334.
[0288] If implant 100 position or results are sub-optimal, the
implant 100 preferably may be collapsed and repositioned in the LAA
10. In some embodiments, the implant 100 is still attached to an
implant release and recapture mechanism 200 and the
radial-reduction of the implant 100 is accomplished by the
actuation of the implant actuation shaft 334. In other embodiments,
the implant 100 must be reattached to the implant release and
recapture mechanism 200 before the radial-reduction of the implant
100 can be accomplished by the actuation of the implant actuation
shaft 334. To collapse and reposition an implant 100 in one
embodiment under fluoroscopy, the deployment handle 400 preferably
is advanced distally to place the radiopaque marker 360 of the
axially moveable core 304 at the distal hub 108 of the implant 100.
The distal end of the transseptal sheath 520 preferably is aligned
with the distal end of the flexible segment 384. The control knob
408 preferably is rotated until the implant 100 has been collapsed
to approximately 1/3.sup.rd or less of its expanded diameter. The
control knob 408 preferably acts on the control line 312 to place
tension on the proximal hub 104 of the implant 100, pulling the
proximal hub 104 of the implant 100 proximally relative the distal
hub 108 of the implant 100 to collapse the implant 100. The implant
100 preferably can be repositioned and re-expanded. In another
embodiment, an implant actuation shaft 334 is reintroduced or
advanced distally within a radially-enlarged implant 100 and
advanced to the distal end 102 of the implant 100.
[0289] The stability of the implant 100 preferably is verified in
several views. Stability tests preferably are preformed in the
following manner. A contrast media filled syringe preferably is
connected to the distal injection port 414 of the deployment handle
400. Under fluoroscopy, at least about a 10 mm gap between the tip
of the transseptal sheath 520 and the proximal hub 110 of the
implant 100 is preferably confirmed. The stability of the implant
100 in the LAA 10 preferably is evaluated using fluoroscopy and
echocardiography. The recapture sheath Touhy-Borst valve 530
preferably is loosened. Then the deployment handle 400 preferably
is alternately retracted and advanced about 5-10 mm while
maintaining the position of the transseptal sheath 520 and
simultaneously injecting contrast media through the distal
injection port 414. This tests how well the implant is held within
the LAA 10. If the implant stability tests are unacceptable, the
implant 100 preferably may be collapsed and repositioned as
described above. If repositioning the implant 100 does not achieve
an acceptable result, the implant 100 preferably may be collapsed
and recaptured as described further below.
[0290] The implant 100 preferably meets the following acceptance
criteria, associated with the assessment techniques listed below,
prior to being released. The assessment techniques to be evaluated
preferably include 1) residual compression; 2) implant location; 3)
anchor engagement; 4) seal quality; and 5) stability. For residual
compression, the implant diameter O, as measured by fluoroscopic
imaging, preferably is less than the maximum expanded diameter of
the implant 100. For implant location, the proximal sealing surface
of the implant 100 preferably is positioned between the LAA 10
ostium and sources of thrombus formation (pectinates, secondary
lobes, etc.) (preferably imaged in at least two views). For anchor
engagement, the implant frame 101 preferably is positioned within
the LAA 10 so as to completely engage a middle row of anchors 118
in an LAA 10 wall (preferably imaged in at least two views). For
seal quality, the contrast injections preferably show leakage rated
no worse than mild (preferably defined as a flow of contrast media,
well defined, and filling one-third of the LAA 10 during a proximal
injection over a period of up to about five ventricular beats,
preferably imaged in at least two views). For stability, there
preferably is no migration or movement of the implant 100 relative
to the LAA 10 wall as a result of the Stability Test.
[0291] If implant 100 recapture is necessary, because a different
size implant 100 is necessary or desired, or if acceptable
positioning or sealing cannot be achieved, the implant 100
preferably is fully collapsed as described above. In one
embodiment, once the implant 100 is collapsed, the locking collar
315 of the peel away sheath 314 preferably is unlocked. The
peel-away portion 524 of the peel-away sheath 314 preferably is
split up to the reinforced section 317 and removed. The reinforced
section 317 of the peel-away sheath 314 preferably is slid
proximally to the hub of the recapture sheath 522. The Touhy-Borst
valve 530 on the proximal end of the recapture sheath 522
preferably is slightly loosened to allow smooth movement of the
sheath 522 over deployment catheter 302 without allowing air to
enter past the Touhy-Borst valve 530 seal. By removing the
peel-away portion 524 of peel-away sheath 314, the recapture sheath
522 can now be advanced further distally relative to the
transseptal sheath 520.
[0292] While holding the deployment catheter 302 and transseptal
sheath 520 in place, the recapture sheath 522 preferably is
advanced distally into the transseptal sheath 520 until a half
marker band 536 on the recapture sheath 522 is aligned with a full
marker band 521 on the transseptal sheath 520. This preferably
exposes the recapture flares 510 outside the transseptal
sheath.
[0293] The collapsed implant 100 preferably is retracted into the
recapture sheath 522 by simultaneously pulling the deployment
handle 400 and maintaining the position of the recapture sheath 522
until approximately half the implant 100 is seated in the recapture
sheath 522. The Touhy-Borst valve 530 on the recapture sheath 522
preferably is tightened over the deployment catheter 302. The
recapture sheath 522 and implant 100 preferably are retracted into
the transseptal sheath 520 by pulling on the recapture sheath 522
while maintaining the position of the transseptal sheath 520,
preferably maintaining left atrial access. The recapture flares 510
of the recapture sheath 522 preferably cover at least some of the
anchor elements 195 on the implant 100 as the implant is retracted
proximally into the transseptal sheath 520. Further details are
described above with respect to FIGS. 15C-15E.
[0294] If the implant's position and function are acceptable, and
implant recapture is not necessary, the implant 100 preferably is
released from the delivery system 50. In one embodiment, under
fluoroscopy, the transseptal sheath 520 is advanced to the proximal
hub 104 of the implant 100 for support. The release knob 410 on the
proximal end of the deployment handle 400 preferably is rotated to
release the implant 100. Rotating the release knob 410 preferably
causes a threaded portion of the distal shaft 344 of the axially
movable core 304 to rotate with respect to the threaded aperture
346 such that the threaded portion of the distal shaft 344
preferably is decoupled from the implant 100. Under fluoroscopy,
after the axially movable core 304 is decoupled from the implant
100, the release knob 410 preferably is refracted until the distal
end 310 of the axially movable core 304 is at least about 2 cm
within the transseptal sheath 520.
[0295] In one embodiment a disconnect mount interface 180 on the
proximal end 104 of the implant 100 is connected to a disconnect
mount 236 on a catheter system 300 which can provide releasable
concentric loading to the implant 100 as described above. In one
embodiment, the concentric loading is concentric tension. In one
embodiment the concentric loading is provided by a disconnect mount
interface 180 with a finger interface 182 which interacts with a
flexible finger 238 on the disconnect mount 236. The flexible
finger 238 is engaged with a finger interface 182 and a lock tube
234 secures the engagement between the flexible finger 238 and the
finger interface 182. Under fluoroscopy, the implant 100 may be
detached by removing the lock tube 234 from the flexible finger 238
and finger interface 182. In some embodiments, the lock tube 234
may be rotated to threadably disengage from a catheter 302 to
unlock the lock tube 234. In other embodiments no lock tube 234 is
necessary. In other embodiments sufficient proximal retraction of
the implant actuation shaft 334 is required in order to release the
disconnect mount interface 180 from the disconnect mount 236, as
described above.
[0296] Under fluoroscopy, while assuring that transseptal access is
maintained, the delivery system 50 preferably is retracted and
removed through the transseptal sheath 520. Under fluoroscopy, the
transseptal sheath 520 position preferably is verified to be
approximately 1 cm away from the face of the implant 100. Contrast
injections, fluoroscopy and/or echocardiography preferably may be
used to confirm proper positioning and delivery of the implant 100
and containment of the LAA 10. The transseptal sheath 520
preferably is withdrawn.
[0297] Throughout this application the terms implant and occlusion
device have been used. One of ordinary skill in the art will
appreciate that all of the disclosures herein are applicable to a
wide variety of structures that include both implants that may or
may not also be occlusion devices. Routine experimentation will
demonstrate those limited circumstances under which certain
disclosures and combinations thereof are not beneficial.
[0298] Further details regarding left atrial appendages devices and
related methods are disclosed in U.S. Pat. No. 6,152,144, titled
"Method and Device for Left Atrial Appendage Occlusion," filed Nov.
6, 1998, U.S. patent application Ser. No. 09/435,562, filed Nov. 8,
1999, U.S. patent application Ser. No. 10/033,371, titled "Method
and Device for Left Atrial Appendage Occlusion," filed Oct. 19,
2001, and U.S. application Ser. No. 10/642,384, filed Aug. 15,
2003, titled "System and Method for Delivering a Left Atrial
Appendage Containment Device," published as U.S. Publication No.
2005/0038470. The entirety of each of these is hereby incorporated
by reference.
[0299] 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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