U.S. patent application number 15/842559 was filed with the patent office on 2018-05-03 for replacement valve and anchor.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. The applicant listed for this patent is BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Brian D. Brandt, Jean-Pierre Dueri, Robert A. Geshlider, Ulrich R. Haug, Dwight P. Morejohn, Amr Salahieh, Hans F. Valencia.
Application Number | 20180116792 15/842559 |
Document ID | / |
Family ID | 34679269 |
Filed Date | 2018-05-03 |
United States Patent
Application |
20180116792 |
Kind Code |
A1 |
Salahieh; Amr ; et
al. |
May 3, 2018 |
REPLACEMENT VALVE AND ANCHOR
Abstract
Apparatus for endovascularly replacing a patient's heart valve,
including: a replacement valve adapted to be delivered
endovascularly to a vicinity of the heart valve; an expandable
anchor adapted to be delivered endovascularly to the vicinity of
the heart valve; and a lock mechanism configured to maintain a
minimum amount of anchor expansion. The invention also includes a
method for endovascularly replacing a patient's heart valve. In
some embodiments the method includes the steps of: endovascularly
delivering a replacement valve and an expandable anchor to a
vicinity of the heart valve; expanding the anchor to a deployed
configuration; and locking the anchor in the deployed
configuration.
Inventors: |
Salahieh; Amr; (Saratoga,
CA) ; Brandt; Brian D.; (Morgan Hill, CA) ;
Morejohn; Dwight P.; (Davis, CA) ; Haug; Ulrich
R.; (Campbell, CA) ; Dueri; Jean-Pierre; (Los
Gatos, CA) ; Valencia; Hans F.; (Santa Clara, CA)
; Geshlider; Robert A.; (San Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOSTON SCIENTIFIC SCIMED, INC. |
Maple Grove |
MN |
US |
|
|
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
MAPLE GROVE
MN
|
Family ID: |
34679269 |
Appl. No.: |
15/842559 |
Filed: |
December 14, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15842503 |
Dec 14, 2017 |
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15842559 |
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15842426 |
Dec 14, 2017 |
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15842503 |
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15842306 |
Dec 14, 2017 |
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15842426 |
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15675978 |
Aug 14, 2017 |
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15842306 |
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14147902 |
Jan 6, 2014 |
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15675978 |
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13155902 |
Jun 8, 2011 |
8623078 |
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14147902 |
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10911059 |
Aug 3, 2004 |
7959672 |
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13155902 |
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10746872 |
Dec 23, 2003 |
8182528 |
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10911059 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2250/0069 20130101;
A61F 2/2412 20130101; A61F 2220/0016 20130101; A61F 2230/0065
20130101; A61F 2220/005 20130101; A61F 2/2418 20130101; A61F
2220/0058 20130101; A61F 2230/0054 20130101; A61F 2230/0078
20130101; A61F 2230/005 20130101; A61F 2/2439 20130101 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A prosthetic heart valve, comprising: a stent having an inflow
end region and an outflow end region; wherein the inflow end region
has an inflow outer diameter; wherein the outflow end region has an
outflow outer diameter; wherein the outflow outer diameter is
greater than the inflow outer diameter; a plurality of leaflets
coupled to the stent; and a sealing member coupled to the
stent.
2. The prosthetic heart valve of claim 1, wherein the sealing
member is designed to shift between a first configuration and a
bunched configuration.
3. The prosthetic heart valve of claim 1, wherein the stent
includes a self-expanding material.
4. The prosthetic heart valve of claim 1, wherein the stent
includes a nickel-titanium alloy.
5. The prosthetic heart valve of claim 1, wherein the stent
includes a cobalt-chromium alloy.
6. The prosthetic heart valve of claim 1, wherein the sealing
member includes a fabric.
7. The prosthetic heart valve of claim 1, wherein the sealing
member includes a pocket.
8. The prosthetic heart valve of claim 1, wherein the sealing
member includes a sac.
9. An implantable prosthetic heart valve, comprising: a stent
having an inflow region, a central region, and an outflow region; a
plurality of leaflets coupled to the stent; wherein the outflow
region has an outflow outer diameter; wherein the central region
has a central outer diameter; wherein the inflow region has an
inflow outer diameter; wherein the outflow outer diameter is
greater than the inflow outer diameter, the central outer diameter,
or both; a sealing member coupled to the stent.
10. The implantable prosthetic heart valve of claim 9, wherein the
sealing member is coupled to an outer surface of the stent.
11. The implantable prosthetic heart valve of claim 9, wherein at
least a portion of the sealing member is disposed along the central
region.
12. The implantable prosthetic heart valve of claim 9, wherein the
stent includes a self-expanding material.
13. The implantable prosthetic heart valve of claim 9, wherein the
stent includes a nickel-titanium alloy.
14. The implantable prosthetic heart valve of claim 9, wherein the
stent includes a cobalt-chromium alloy.
15. The implantable prosthetic heart valve of claim 9, further
comprising a sealing member coupled to the stent.
16. The implantable prosthetic heart valve of claim 9, wherein the
sealing member includes a pocket.
17. The implantable prosthetic heart valve of claim 9, wherein the
sealing member includes a sac.
18. An implantable prosthetic heart valve, comprising: an
expandable frame having an inflow region, a central region, and an
outflow region; a plurality of leaflets coupled to the frame;
wherein the outflow region has an outflow outer diameter; wherein
the central region has a central outer diameter; wherein the
outflow outer diameter is greater than the central outer diameter;
and a sealing member coupled to an outer surface of the frame,
wherein at least a portion of the sealing member extends along the
central region.
19. The implantable prosthetic heart valve of claim 18, wherein the
sealing member includes a fillable region.
20. The implantable prosthetic heart valve of claim 18, wherein the
sealing member is designed to change shape and conform to a target
region when the frame is expanded.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No.
15/842,503, filed Dec. 14, 2017, which is a continuation of U.S.
Ser. No. 15/842,426, filed Dec. 14, 2017, which is a continuation
of U.S. Ser. No. 15/842,306, filed Dec. 14, 2017, which is a
continuation of U.S. Ser. No. 15/675,978, filed Aug. 14, 2017,
which is a continuation of Ser. No. 14/147,902, filed Jan. 6, 2014
which is a Divisional application of Ser. No. 13/155,902, filed
Jun. 8, 2011, now U.S. Pat. No. 8,623,078, which is a Continuation
application of Ser. No. 10/911,059, filed Aug. 3, 2004, now U.S.
Pat. No. 7,959,672, which is a Continuation application of Ser. No.
10/746,872, filed Dec. 23, 2003, now U.S. Pat. No. 8,182,528, the
contents of each of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to methods and apparatus for
endovascularly replacing a heart valve. More particularly, the
present invention relates to methods and apparatus for
endovascularly replacing a heart valve with a replacement valve
using an expandable and retrievable anchor.
[0003] Heart valve surgery is used to repair or replace diseased
heart valves. Valve surgery is an open-heart procedure conducted
under general anesthesia. An incision is made through the patient's
sternum (sternotomy), and the patient's heart is stopped while
blood flow is rerouted through a heart-lung bypass machine.
[0004] Valve replacement may be indicated when there is a narrowing
of the native heart valve, commonly referred to as stenosis, or
when the native valve leaks or regurgitates. When replacing the
valve, the native valve is excised and replaced with either a
biologic or a mechanical valve. Mechanical valves require lifelong
anticoagulant medication to prevent blood clot formation, and
clicking of the valve often may be heard through the chest.
Biologic tissue valves typically do not require such medication.
Tissue valves may be obtained from cadavers or may be porcine or
bovine, and are commonly attached to synthetic rings that are
secured to the patient's heart.
[0005] Valve replacement surgery is a highly invasive operation
with significant concomitant risk. Risks include bleeding,
infection, stroke, heart attack, arrhythmia, renal failure, adverse
reactions to the anesthesia medications, as well as sudden death.
2-5% of patients die during surgery.
[0006] Post-surgery, patients temporarily may be confused due to
emboli and other factors associated with the heart-lung machine.
The first 2-3 days following surgery are spent in an intensive care
unit where heart functions can be closely monitored. The average
hospital stay is between 1 to 2 weeks, with several more weeks to
months required for complete recovery.
[0007] In recent years, advancements in minimally invasive surgery
and interventional cardiology have encouraged some investigators to
pursue percutaneous replacement of the aortic heart valve.
Percutaneous Valve Technologies ("PVT") of Fort Lee, New Jersey,
has developed a balloon-expandable stent integrated with a
bioprosthetic valve. The stent/valve device is deployed across the
native diseased valve to permanently hold the valve open, thereby
alleviating a need to excise the native valve and to position the
bioprosthetic valve in place of the native valve. PVT's device is
designed for delivery in a cardiac catheterization laboratory under
local anesthesia using fluoroscopic guidance, thereby avoiding
general anesthesia and open-heart surgery. The device was first
implanted in a patient in April of 2002.
[0008] PVT's device suffers from several drawbacks. Deployment of
PVT's stent is not reversible, and the stent is not retrievable.
This is a critical drawback because improper positioning too far up
towards the aorta risks blocking the coronary ostia of the patient.
Furthermore, a misplaced stent/valve in the other direction (away
from the aorta, closer to the ventricle) will impinge on the mitral
apparatus and eventually wear through the leaflet as the leaflet
continuously rubs against the edge of the stent/valve.
[0009] Another drawback of the PVT device is its relatively large
cross-sectional delivery profile. The PVT system's stent/valve
combination is mounted onto a delivery balloon, making retrograde
delivery through the aorta challenging. An antegrade transseptal
approach may therefore be needed, requiring puncture of the septum
and routing through the mitral valve, which significantly increases
complexity and risk of the procedure. Very few cardiologists are
currently trained in performing a transseptal puncture, which is a
challenging procedure by itself.
[0010] Other prior art replacement heart valves use self-expanding
stents as anchors. In the endovascular aortic valve replacement
procedure, accurate placement of aortic valves relative to coronary
ostia and the mitral valve is critical. Standard self-expanding
systems have very poor accuracy in deployment, however. Often the
proximal end of the stent is not released from the delivery system
until accurate placement is verified by fluoroscopy, and the stent
typically jumps once released. It is therefore often impossible to
know where the ends of the stent will be with respect to the native
valve, the coronary ostia and the mitral valve.
[0011] Also, visualization of the way the new valve is functioning
prior to final deployment is very desirable. Visualization prior to
final and irreversible deployment cannot be done with standard
self-expanding systems, however, and the replacement valve is often
not fully functional before final deployment.
[0012] Another drawback of prior art self-expanding replacement
heart valve systems is their lack of radial strength. In order for
self-expanding systems to be easily delivered through a delivery
sheath, the metal needs to flex and bend inside the delivery
catheter without being plastically deformed. In arterial stents,
this is not a challenge, and there are many commercial arterial
stent systems that apply adequate radial force against the vessel
wall and yet can collapse to a small enough of a diameter to fit
inside a delivery catheter without plastically deforming. However
when the stent has a valve fastened inside it, as is the case in
aortic valve replacement, the anchoring of the stent to vessel
walls is significantly challenged during diastole. The force to
hold back arterial pressure and prevent blood from going back
inside the ventricle during diastole will be directly transferred
to the stent/vessel wall interface. Therefore the amount of radial
force required to keep the self expanding stent/valve in contact
with the vessel wall and not sliding will be much higher than in
stents that do not have valves inside of them. Moreover, a
self-expanding stent without sufficient radial force will end up
dilating and contracting with each heartbeat, thereby distorting
the valve, affecting its function and possibly migrating and
dislodging completely. Simply increasing strut thickness of the
self-expanding stent is not a practical solution as it runs the
risk of larger profile and/or plastic deformation of the
self-expanding stent.
[0013] U.S. patent application Serial No. 2002/0151970 to Garrison
et al. describes a two-piece device for replacement of the aortic
valve that is adapted for delivery through a patient's aorta. A
stent is endovascularly placed across the native valve, then a
replacement valve is positioned within the lumen of the stent. By
separating the stent and the valve during delivery, a profile of
the device's delivery system may be sufficiently reduced to allow
aortic delivery without requiring a transseptal approach. Both the
stent and a frame of the replacement valve may be
balloon-expandable or self-expanding.
[0014] While providing for an aortic approach, devices described in
the Garrison patent application suffer from several drawbacks.
First, the stent portion of the device is delivered across the
native valve as a single piece in a single step, which precludes
dynamic repositioning of the stent during delivery. Stent
foreshortening or migration during expansion may lead to improper
alignment.
[0015] Additionally, Garrison's stent simply crushes the native
valve leaflets against the heart wall and does not engage the
leaflets in a manner that would provide positive registration of
the device relative to the native position of the valve. This
increases an immediate risk of blocking the coronary ostia, as well
as a longer-term risk of migration of the device post-implantation.
Further still, the stent comprises openings or gaps in which the
replacement valve is seated post-delivery. Tissue may protrude
through these gaps, thereby increasing a risk of improper seating
of the valve within the stent.
[0016] In view of drawbacks associated with previously known
techniques for endovascularly replacing a heart valve, it would be
desirable to provide methods and apparatus that overcome those
drawbacks.
SUMMARY OF THE INVENTION
[0017] One aspect of the invention provides an apparatus for
endovascularly replacing a patient's heart valve, including: a
replacement valve adapted to be delivered endovascularly to a
vicinity of the heart valve; an expandable anchor adapted to be
delivered endovascularly to the vicinity of the heart valve; and a
lock mechanism configured to maintain a minimum amount of anchor
expansion. The lock mechanism may include first and second mating
interlocking elements. An actuator may be provided to apply an
actuation force on the anchor.
[0018] Another aspect of the invention provides a method for
endovascularly replacing a patient's heart valve. In some
embodiments the method includes the steps of: endovascularly
delivering a replacement valve and an expandable anchor to a
vicinity of the heart valve; expanding the anchor to a deployed
configuration; and locking the anchor in the deployed
configuration.
[0019] Yet another aspect of the invention provides an apparatus
for endovascularly replacing a patient's heart valve, including: an
anchor comprising a lip region and a skirt region; a replacement
valve coupled to the anchor; and a lock, wherein the lip region and
skirt region are configured for percutaneous expansion to engage
the patient's heart valve, and wherein the lock is configured to
maintain such expansion.
INCORPORATION BY REFERENCE
[0020] All publications and patent applications mentioned in this
specification are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated to be incorporated by
reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The novel features of the invention are set forth with
particularity in the appended claims. A better understanding of the
features and advantages of the present invention will be obtained
by reference to the following detailed description that sets forth
illustrative embodiments, in which the principles of the invention
are utilized, and the accompanying drawings of which:
[0022] FIGS. 1A-B are elevational views of a replacement heart
valve and anchor according to one embodiment of the invention.
[0023] FIGS. 2A-B are sectional views of the anchor and valve of
FIG. 1.
[0024] FIGS. 3A-B show delivery and deployment of a replacement
heart valve and anchor, such as the anchor and valve of FIGS. 1 and
2.
[0025] FIGS. 4A-F also show delivery and deployment of a
replacement heart valve and anchor, such as the anchor and valve of
FIGS. 1 and 2.
[0026] FIGS. 5A-F show the use of a replacement heart valve and
anchor to replace an aortic valve.
[0027] FIGS. 6A-F show the use of a replacement heart valve and
anchor with a positive registration feature to replace an aortic
valve.
[0028] FIG. 7 shows the use of a replacement heart valve and anchor
with an alternative positive registration feature to replace an
aortic valve.
[0029] FIGS. 8A-C show another embodiment of a replacement heart
valve and anchor according to the invention.
[0030] FIGS. 9A-H show delivery and deployment of the replacement
heart valve and anchor of FIG. 8.
[0031] FIG. 10 is a cross-sectional drawing of the delivery system
used with the method and apparatus of FIGS. 8 and 9.
[0032] FIGS. 11A-C show alternative locks for use with replacement
heart valves and anchors of this invention.
[0033] FIGS. 12A-C show a vessel wall engaging lock for use with
replacement heart valves and anchors of this invention.
[0034] FIG. 13 demonstrates paravalvular leaking around a
replacement heart valve and anchor.
[0035] FIG. 14 shows a seal for use with a replacement heart valve
and anchor of this invention.
[0036] FIGS. 15A-E show alternative arrangements of seals on a
replacement heart valve and anchor.
[0037] FIGS. 16A-C show alternative seal designs for use with
replacement heart valves and anchors.
[0038] FIGS. 17A-B show an alternative anchor lock embodiment in an
unlocked configuration.
[0039] FIGS. 18A-B show the anchor lock of FIGS. 17A-B in a locked
configuration.
[0040] FIG. 19 shows an alternative anchor deployment tool
attachment and release mechanism for use with the invention.
[0041] FIG. 20 shows the attachment and release mechanism of FIG.
19 in the process of being released.
[0042] FIG. 21 shows the attachment and release mechanism of FIGS.
19 and 20 in a released condition.
[0043] FIG. 22 shows an alternative embodiment of a replacement
heart valve and anchor and a deployment tool according to the
invention in an undeployed configuration.
[0044] FIG. 23 shows the replacement heart valve and anchor of FIG.
22 in a partially deployed configuration.
[0045] FIG. 24 shows the replacement heart valve and anchor of
FIGS. 22 and 23 in a more fully deployed configuration but with the
deployment tool still attached.
[0046] FIG. 25 shows yet another embodiment of the delivery and
deployment apparatus of the invention in use with a replacement
heart valve and anchor.
[0047] FIG. 26 shows the delivery and deployment apparatus of FIG.
25 in the process of deploying a replacement heart valve and
anchor.
[0048] FIG. 27 show an embodiment of the invention employing seals
at the interface of the replacement heart valve and anchor and the
patient's tissue.
[0049] FIG. 28 is a longitudinal cross-sectional view of the seal
shown in FIG. 27 in compressed form.
[0050] FIG. 29 is a transverse cross-sectional view of the seal
shown in FIG. 28.
[0051] FIG. 30 is a longitudinal cross-sectional view of the seal
shown in FIG. 27 in expanded form.
[0052] FIG. 31 is a transverse cross-sectional view of the seal
shown in FIG. 30.
[0053] FIG. 32 shows yet another embodiment of the replacement
heart valve and anchor of this invention in an undeployed
configuration.
[0054] FIG. 33 shows the replacement heart valve and anchor of FIG.
32 in a deployed configuration.
[0055] FIG. 34 shows the replacement heart valve and anchor of
FIGS. 32 and 33 deployed in a patient's heart valve.
[0056] FIGS. 35A-H show yet another embodiment of a replacement
heart valve, anchor and deployment system according to this
invention.
[0057] FIGS. 36A-E show more detail of the anchor of the embodiment
shown in FIGS. 35A-H.
[0058] FIGS. 37A-B show other embodiments of the replacement heart
valve and anchor of the invention.
[0059] FIGS. 38A-C illustrate a method for endovascularly replacing
a patient's diseased heart valve.
DETAILED DESCRIPTION OF THE INVENTION
[0060] While preferred embodiments of the present invention have
been shown and described herein, it will be obvious to those
skilled in the art that such embodiments are provided by way of
example only. Numerous variations, changes, and substitutions will
now occur to those skilled in the art without departing from the
invention. It should be understood that various alternatives to the
embodiments of the invention described herein may be employed in
practicing the invention. It is intended that the following claims
define the scope of the invention and that methods and structures
within the scope of these claims and their equivalents be covered
thereby.
[0061] With reference now to FIGS. 1-4, a first embodiment of
replacement heart valve apparatus in accordance with the present
invention is described, including a method of actively
foreshortening and expanding the apparatus from a delivery
configuration and to a deployed configuration. Apparatus 10
comprises replacement valve 20 disposed within and coupled to
anchor 30. FIG. 1 schematically illustrate individual cells of
anchor 30 of apparatus 10, and should be viewed as if the
cylindrical anchor has been cut open and laid flat. FIG. 2
schematically illustrate a detail portion of apparatus 10 in
side-section.
[0062] Anchor 30 has a lip region 32, a skirt region 34 and a body
region 36. First, second and third posts 38a, 38b and 38c,
respectively, are coupled to skirt region 34 and extend within
lumen 31 of anchor 30. Posts 38 preferably are spaced 120.degree.
apart from one another about the circumference of anchor 30.
[0063] Anchor 30 preferably is fabricated by using self-expanding
patterns (laser cut or chemically milled), braids and materials,
such as a stainless steel, nickel-titanium ("Nitinol") or cobalt
chromium but alternatively may be fabricated using
balloon-expandable patterns where the anchor is designed to
plastically deform to it's final shape by means of balloon
expansion. Replacement valve 20 is preferably from biologic
tissues, e.g. porcine valve leaflets or bovine or equine
pericardium tissues, alternatively it can be made from tissue
engineered materials (such as extracellular matrix material from
Small Intestinal Submucosa (SIS)) but alternatively may be
prosthetic from an elastomeric polymer or silicone, Nitinol or
stainless steel mesh or pattern (sputtered, chemically milled or
laser cut). The leaflet may also be made of a composite of the
elastomeric or silicone materials and metal alloys or other fibers
such Kevlar or carbon. Annular base 22 of replacement valve 20
preferably is coupled to skirt region 34 of anchor 30, while
commissures 24 of replacement valve leaflets 26 are coupled to
posts 38.
[0064] Anchor 30 may be actuated using external non-hydraulic or
non-pneumatic force to actively foreshorten in order to increase
its radial strength. As shown below, the proximal and distal end
regions of anchor 30 may be actuated independently. The anchor and
valve may be placed and expanded in order to visualize their
location with respect to the native valve and other anatomical
features and to visualize operation of the valve. The anchor and
valve may thereafter be repositioned and even retrieved into the
delivery sheath or catheter. The apparatus may be delivered to the
vicinity of the patient's aortic valve in a retrograde approach in
a catheter having a diameter no more than 23 french, preferably no
more than 21 french, more preferably no more than 19 french, or
more preferably no more than 17 french. Upon deployment the anchor
and replacement valve capture the native valve leaflets and
positively lock to maintain configuration and position.
[0065] A deployment tool is used to actuate, reposition, lock
and/or retrieve anchor 30. In order to avoid delivery of anchor 30
on a balloon for balloon expansion, a non-hydraulic or
non-pneumatic anchor actuator is used. In this embodiment, the
actuator is a deployment tool that includes distal region control
wires 50, control rods or tubes 60 and proximal region control
wires 62. Locks 40 include posts or arms 38 preferably with male
interlocking elements 44 extending from skirt region 34 and mating
female interlocking elements 42 in lip region 32. Male interlocking
elements 44 have eyelets 45. Control wires 50 pass from a delivery
system for apparatus 10 through female interlocking elements 42,
through eyelets 45 of male interlocking elements 44, and back
through female interlocking elements 42, such that a double strand
of wire 50 passes through each female interlocking element 42 for
manipulation by a medical practitioner external to the patient to
actuate and control the anchor by changing the anchor's shape.
Control wires 50 may comprise, for example, strands of suture.
[0066] Tubes 60 are reversibly coupled to apparatus 10 and may be
used in conjunction with wires 50 to actuate anchor 30, e.g., to
foreshorten and lock apparatus 10 in the fully deployed
configuration. Tubes 60 also facilitate repositioning and retrieval
of apparatus 10, as described hereinafter. For example, anchor 30
may be foreshortened and radially expanded by applying a distally
directed force on tubes 60 while proximally retracting wires 50. As
seen in FIG. 3, control wires 62 pass through interior lumens 61 of
tubes 60. This ensures that tubes 60 are aligned properly with
apparatus 10 during deployment and foreshortening. Control wires 62
can also actuate anchor 60; proximally directed forces on control
wires 62 contacts the proximal lip region 32 of anchor 30. Wires 62
also act to couple and decouple tubes 60 from apparatus 10. Wires
62 may comprise, for example, strands of suture.
[0067] FIGS. 1A and 2A illustrate anchor 30 in a delivery
configuration or in a partially deployed configuration (e.g., after
dynamic self-expansion expansion from a constrained delivery
configuration within a delivery sheath). Anchor 30 has a relatively
long length and a relatively small width in the delivery or
partially deployed configuration, as compared to the foreshortened
and fully deployed configuration of FIGS. 1B and 2B.
[0068] In FIGS. 1A and 2A, replacement valve 20 is collapsed within
lumen 31 of anchor 30. Retraction of wires 50 relative to tubes 60
foreshortens anchor 30, which increases the anchor's width while
decreasing its length. Such foreshortening also properly seats
replacement valve 20 within lumen 31 of anchor 30. Imposed
foreshortening will enhance radial force applied by apparatus 10 to
surrounding tissue over at least a portion of anchor 30. In some
embodiments, the anchor exerts an outward force on surrounding
tissue to engage the tissue in such way to prevent migration of
anchor caused by force of blood against closed leaflet during
diastole. This anchoring force is preferably 1 to 2 lbs, more
preferably 2 to 4 lbs, or more preferably 4 to 10 lbs. In other
embodiments, the anchoring force is preferably greater than 1
pound, more preferably greater than 2 pounds, or more preferably
greater than 4 pounds Enhanced radial force of the anchor is also
important for enhanced crush resistance of the anchor against the
surrounding tissue due to the healing response (fibrosis and
contraction of annulus over a longer period of time) or to dynamic
changes of pressure and flow at each heart beat In an alternative
embodiment, the anchor pattern or braid is designed to have gaps or
areas where the native tissue is allowed to protrude through the
anchor slightly (not shown) and as the foreshortening is applied,
the tissue is trapped in the anchor. This feature would provide
additional `means to prevent anchor migration and enhance long term
stability of the device.
[0069] Deployment of apparatus 10 is fully reversible until lock 40
has been locked via mating of male interlocking elements 44 with
female interlocking elements 42. Deployment is then completed by
decoupling tubes 60 from lip section 32 of anchor 30 by retracting
one end of each wire 62 relative to the other end of the wire, and
by retracting one end of each wire 50 relative to the other end of
the wire until each wire has been removed from eyelet 45 of its
corresponding male interlocking element 44.
[0070] As best seen in FIG. 2B, body region 36 of anchor 30
optionally may comprise barb elements 37 that protrude from anchor
30 in the fully deployed configuration, for example, for engagement
of a patient's native valve leaflets and to preclude migration of
the apparatus.
[0071] With reference now to FIG. 3, a delivery and deployment
system for a self-expanding embodiment of apparatus 10 including a
sheath 110 having a lumen 112. Self-expanding anchor 30 is
collapsible to a delivery configuration within lumen 112 of sheath
110, such that apparatus 10 may be delivered via delivery system
100. As seen in FIG. 3A, apparatus 10 may be deployed from lumen
112 by retracting sheath 110 relative to apparatus 10, control
wires 50 and tubes 60, which causes anchor 30 to dynamically
self-expand to a partially deployed configuration. Control wires 50
then are retracted relative to apparatus 10 and tubes 60 to impose
foreshortening upon anchor 30, as seen in FIG. 3B.
[0072] During foreshortening, tubes 60 push against lip region 32
of anchor 30, while wires 50 pull on posts 38 of the anchor. Wires
62 may be retracted along with wires 50 to enhance the
distally-directed pushing force applied by tubes 60 to lip region
32. Continued retraction of wires 50 relative to tubes 60 would
lock locks 40 and fully deploy apparatus 10 with replacement valve
20 properly seated within anchor 30, as in FIGS. 1B and 2B.
Apparatus 10 comprises enhanced radial strength in the fully
deployed configuration as compared to the partially deployed
configuration of FIG. 3A. Once apparatus 10 has been fully
deployed, wires 50 and 62 may be removed from apparatus 10, thereby
separating delivery system 100 and tubes 60 from the apparatus.
[0073] Deployment of apparatus 10 is fully reversible until locks
40 have been actuated. For example, just prior to locking the
position of the anchor and valve and the operation of the valve may
be observed under fluoroscopy. If the position needs to be changed,
by alternately relaxing and reapplying the proximally directed
forces exerted by control wires 50 and/or control wires 62 and the
distally directed forces exerted by tubes 60, expansion and
contraction of the lip and skirt regions of anchor 30 may be
independently controlled so that the anchor and valve can be moved
to, e.g., avoid blocking the coronary ostia or impinging on the
mitral valve. Apparatus 10 may also be completely retrieved within
lumen 112 of sheath 110 by simultaneously proximally retracting
wires 50 and tubes 60/wires 62 relative to sheath 110. Apparatus 10
then may be removed from the patient or repositioned for subsequent
redeployment.
[0074] Referring now to FIG. 4, step-by-step deployment of
apparatus 10 via delivery system 100 is described. In FIG. 4A,
sheath 110 is retracted relative to apparatus 10, wires 50 and
tubes 60, thereby causing self-expandable anchor 30 to dynamically
self-expand apparatus 10 from the collapsed delivery configuration
within lumen 112 of sheath 110 to the partially deployed
configuration. Apparatus 10 may then be dynamically repositioned
via tubes 60 to properly orient the apparatus, e.g. relative to a
patient's native valve leaflets.
[0075] In FIG. 4B, control wires 50 are retracted while tubes 60
are advanced, thereby urging lip region 32 of anchor 30 in a distal
direction while urging posts 38 of the anchor in a proximal
direction. This foreshortens apparatus 10, as seen in FIG. 4C.
Deployment of apparatus 10 is fully reversible even after
foreshortening has been initiated and has advanced to the point
illustrated in FIG. 4C.
[0076] In FIG. 4D, continued foreshortening causes male
interlocking elements 44 of locks 40 to engage female interlocking
elements 42. The male elements mate with the female elements,
thereby locking apparatus 10 in the foreshortened configuration, as
seen in FIG. 4E. Wires 50 are then pulled through eyelets 45 of
male elements 44 to remove the wires from apparatus 10, and wires
62 are pulled through the proximal end of anchor 30 to uncouple
tubes 60 from the apparatus, thereby separating delivery system 100
from apparatus 10. Fully deployed apparatus 10 is shown in FIG. 4F.
[0077] Referring to FIG. 5, a method of endovascularly replacing a
patient's diseased aortic valve with apparatus 10 and delivery
system 100 is described. As seen in Figure SA, sheath 110 of
delivery system 100, having apparatus 10 disposed therein, is
endovascularly advanced over guide wire G, preferably in a
retrograde fashion (although an antegrade or hybrid approach
alternatively may be used), through a patient's aorta A to the
patient's diseased aortic valve AV. A nosecone 102 precedes sheath
110 in a known manner. In FIG. 5B, sheath 110 is positioned such
that its distal region is disposed within left ventricle LV of the
patient's heart H.
[0077] Apparatus 10 is deployed from lumen 112 of sheath 110, for
example, under fluoroscopic guidance, such that anchor 30 of
apparatus 10 dynamically self-expands to a partially deployed
configuration, as in FIG. 5C. Advantageously, apparatus 10 may be
retracted within lumen 112 of sheath 110 via wires 50--even after
anchor 30 has dynamically expanded to the partially deployed
configuration, for example, to abort the procedure or to reposition
apparatus 10 or delivery system 100. As yet another advantage,
apparatus 10 may be dynamically repositioned, e.g. via sheath 110
and/or tubes 60, in order to properly align the apparatus relative
to anatomical landmarks, such as the patient's coronary ostia or
the patient's native valve leaflets L. When properly aligned, skirt
region 34 of anchor 30 preferably is disposed distal of the
leaflets, while body region 36 is disposed across the leaflets and
lip region 32 is disposed proximal of the leaflets.
[0078] Once properly aligned, wires 50 are retracted relative to
tubes 60 to impose foreshortening upon anchor 30 and expand
apparatus 10 to the fully deployed configuration, as in FIG. 5D.
Foreshortening increases the radial strength of anchor 30 to ensure
prolonged patency of valve annulus An, as well as to provide a
better seal for apparatus 10 that reduces paravalvular
regurgitation. As seen in FIG. 5E, locks 40 maintain imposed
foreshortening. Replacement valve 20 is properly seated within
anchor 30, and normal blood flow between left ventricle LV and
aorta A is thereafter regulated by apparatus 10. Deployment of
apparatus 10 advantageously is fully reversible until locks 40 have
been actuated.
[0079] As seen in FIG. 5F, wires 50 are pulled from eyelets 45 of
male elements 44 of locks 40, tubes 60 are decoupled from anchor
30, e.g. via wires 62, and delivery system 100 is removed from the
patient, thereby completing deployment of apparatus 10. Optional
barb elements 37 engage the patient's native valve leaflets, e.g.
to preclude migration of the apparatus and/or reduce paravalvular
regurgitation.
[0080] With reference now to FIG. 6, a method of endovascularly
replacing a patient's diseased aortic valve with apparatus 10 is
provided, wherein proper positioning of the apparatus is ensured
via positive registration of a modified delivery system to the
patient's native valve leaflets. In FIG. 6A, modified delivery
system 100' delivers apparatus 10 to diseased aortic valve AV
within sheath 110. As seen in FIGS. 6B and 6C, apparatus 10 is
deployed from lumen 112 of sheath 110, for example, under
fluoroscopic guidance, such that anchor 30 of apparatus 10
dynamically self-expands to a partially deployed configuration. As
when deployed via delivery system 100, deployment of apparatus 10
via delivery system 100' is fully reversible until locks 40 have
been actuated.
[0081] Delivery system 100' comprises leaflet engagement element
120, which preferably self-expands along with anchor 30. Engagement
element 120 is disposed between tubes 60 of delivery system 100'
and lip region 32 of anchor 30. Element 120 releasably engages the
anchor. As seen in FIG. 6C, the element is initially deployed
proximal of the patient's native valve leaflets L. Apparatus 10 and
element 120 then may be advanced/dynamically repositioned until
engagement element positively registers against the leaflets,
thereby ensuring proper positioning of apparatus 10. Also delivery
system 100' includes filter structure 61A (e.g., filter membrane or
braid) as part of push tubes 60 to act as an embolic protection
element. Emboli can be generated during manipulation and placement
of anchor from either diseased native leaflet or surrounding aortic
tissue and can cause blockage. Arrows 61B in FIG. 6E show blood
flow through filter structure 61A where blood is allowed to flow
but emboli is trapped in the delivery system and removed with it at
the end of the procedure.
[0082] Alternatively, foreshortening may be imposed upon anchor 30
while element 120 is disposed proximal of the leaflets, as in FIG.
6D. Upon positive registration of element 120 against leaflets L,
element 120 precludes further distal migration of apparatus 10
during additional foreshortening, thereby reducing a risk of
improperly positioning the apparatus. FIG. 6E details engagement of
element 120 against the native leaflets. As seen in FIG. 6F, once
apparatus 10 is fully deployed, element 120, wires 50 and tubes 60
are decoupled from the apparatus, and delivery system 100' is
removed from the patient, thereby completing the procedure.
[0083] With reference to FIG. 7, an alternative embodiment of the
apparatus of FIG. 6 is described, wherein leaflet engagement
element 120 is coupled to anchor 30 of apparatus 10', rather than
to delivery system 100. Engagement element 120 remains implanted in
the patient post-deployment of apparatus 10'. Leaflets L are
sandwiched between lip region 32 of anchor 30 and element 120 in
the fully deployed configuration. In this manner, element 120
positively registers apparatus 10' relative to the leaflets and
precludes distal migration of the apparatus over time.
[0084] Referring now to FIG. 8, an alternative delivery system
adapted for use with a balloon expandable embodiment of the present
invention is described. In FIG. 8A, apparatus 10'' comprises anchor
30' that may be fabricated from balloon-expandable materials.
Delivery system 100'' comprises inflatable member 130 disposed in a
deflated configuration within lumen 31 of anchor 30'. In FIG. 8B,
optional outer sheath 110 is retracted, and inflatable member 130
is inflated to expand anchor 30' to the fully deployed
configuration. As inflatable member 130 is being deflated, as in
earlier embodiments, wires 50 and 62 and tubes 60 may be used to
assist deployment of anchor 30' and actuation of locks 40, as well
as to provide reversibility and retrievability of apparatus 10''
prior to actuation of locks 40. Next, wires 50 and 62 and tubes 60
are removed from apparatus 10'', and delivery system 100'' is
removed, as seen in FIG. 8C.
[0085] As an alternative delivery method, anchor 30' may be
partially deployed via partial expansion of inflatable member 130.
The inflatable member would then be advanced within replacement
valve 20 prior to inflation of inflatable member 130 and full
deployment of apparatus 10''. Inflation pressures used will range
from about 3 to 6 atm, or more preferably from about 4 to 5 atm,
though higher and lower atm pressures may also be used (e.g.,
greater than 3 atm, more preferably greater than 4 atm, more
preferably greater than 5 atm, or more preferably greater than 6
atm). Advantageously, separation of inflatable member 130 from
replacement valve 20, until partial deployment of apparatus 10'' at
a treatment site, is expected to reduce a delivery profile of the
apparatus, as compared to previously known apparatus. This profile
reduction may facilitate retrograde delivery and deployment of
apparatus 10'', even when anchor 30' is balloon-expandable.
[0086] Although anchor 30' has illustratively been described as
fabricated from balloon-expandable materials, it should be
understood that anchor 30' alternatively may be fabricated from
self-expanding materials whose expansion optionally may be
balloon-assisted. In such a configuration, anchor 30' would expand
to a partially deployed configuration upon removal of outer sheath
110. If required, inflatable member 130 then would be advanced
within replacement valve 20 prior to inflation. Inflatable member
130 would assist full deployment of apparatus 10'', for example,
when the radial force required to overcome resistance from
impinging tissue were too great to be overcome simply by
manipulation of wires 50 and tubes 60. Advantageously, optional
placement of inflatable member 130 within replacement valve 20,
only after dynamic self-expansion of apparatus 10'' to the
partially deployed configuration at a treatment site, is expected
to reduce a delivery profile of the apparatus, as compared to
previously known apparatus. This reduction may facilitate
retrograde delivery and deployment of apparatus 10''.
[0087] With reference to FIGS. 9 and 10, methods and apparatus for
a balloon-assisted embodiment of the present invention are
described in greater detail. FIGS. 9 and 10 illustratively show
apparatus 10' of FIG. 7 used in combination with delivery system
100'' of FIG. 8. FIG. 10 illustrates a sectional view of delivery
system 100''. Inner shaft 132 of inflatable member 130 preferably
is about 4 Fr in diameter, and comprises lumen 133 configured for
passage of guidewire G, having a diameter of about 0.035'',
therethrough. Push tubes 60 and pull wires 50 pass through
guidetube 140, which preferably has a diameter of about 15 Fr or
smaller. Guide tube 140 is disposed within lumen 112 of outer
sheath 110, which preferably has a diameter of about 17 Fr or
smaller.
[0088] In FIG. 9A, apparatus 10' is delivered to diseased aortic
valve AV within lumen 112 of sheath 110. In FIG. 9B, sheath 110 is
retracted relative to apparatus 10' to dynamically self-expand the
apparatus to the partially deployed configuration. Also retracted
and removed is nosecone 102 which is attached to a pre-slit lumen
(not shown) that facilitates its removal prior to loading and
advancing of a regular angioplasty balloon catheter over guidewire
and inside delivery system 110.
[0089] In FIG. 9C, pull wires 50 and push tubes 60 are manipulated
from external to the patient to foreshorten anchor 30 and
sufficiently expand lumen 31 of the anchor to facilitate
advancement of inflatable member 130 within replacement valve 20.
Also shown is the tip of an angioplasty catheter 130 being advanced
through delivery system 110.
[0090] The angioplasty balloon catheter or inflatable member 130
then is advanced within the replacement valve, as in FIG. 9D, and
additional foreshortening is imposed upon anchor 30 to actuate
locks 40, as in FIG. 9E. The inflatable member is inflated to
further displace the patient's native valve leaflets L and ensure
adequate blood flow through, and long-term patency of, replacement
valve 20, as in FIG. 9F. Inflatable member 130 then is deflated and
removed from the patient, as in FIG. 9G. A different size
angioplasty balloon catheter could be used to repeat the same step
if deemed necessary by the user. Push tubes 60 optionally may be
used to further set leaflet engagement element 120, or optional
barbs B along posts 38, more deeply within leaflets L, as in FIG.
9H. Then, delivery system 100'' is removed from the patient,
thereby completing percutaneous heart valve replacement.
[0091] As will be apparent to those of skill in the art, the order
of imposed foreshortening and balloon expansion described in FIGS.
9 and 10 is only provided for the sake of illustration. The actual
order may vary according to the needs of a given patient and/or the
preferences of a given medical practitioner. Furthermore,
balloon-assist may not be required in all instances, and the
inflatable member may act merely as a safety precaution employed
selectively in challenging clinical cases.
[0092] Referring now to FIG. 11, alternative locks for use with
apparatus of the present invention are described. In FIG. 11A, lock
40' comprises male interlocking element 44 as described previously.
However, female interlocking element 42' illustratively comprises a
triangular shape, as compared to the round shape of interlocking
element 42 described previously. The triangular shape of female
interlocking element 42' may facilitate mating of male interlocking
element 44 with the female interlocking element without
necessitating deformation of the male interlocking element.
[0093] In FIG. 1iB, lock 40'' comprises alternative male
interlocking element 44' having multiple in-line arrowheads 46
along posts 38. Each arrowhead comprises resiliently deformable
appendages 48 to facilitate passage through female interlocking
element 42. Appendages 48 optionally comprise eyelets 49, such that
control wire 50 or a secondary wire may pass therethrough to
constrain the appendages in the deformed configuration. To actuate
lock 40'', one or more arrowheads 46 of male interlocking element
44' are drawn through female interlocking element 42, and the wire
is removed from eyelets 49, thereby causing appendages 48 to
resiliently expand and actuate lock 40''.
[0094] Advantageously, providing multiple arrowheads 46 along posts
38 yields a ratchet that facilitates in-vivo determination of a
degree of foreshortening imposed upon apparatus of the present
invention. Furthermore, optionally constraining appendages 48 of
arrowheads 46 via eyelets 49 prevents actuation of lock 40'' (and
thus deployment of apparatus of the present invention) even after
male element 44' has been advanced through female element 42. Only
after a medical practitioner has removed the wire constraining
appendages 48 is lock 40'' fully engaged and deployment no longer
reversible.
[0095] Lock 40''' of FIG. 11C is similar to lock 40'' of FIG. 11B,
except that optional eyelets 49 on appendages 48 have been replaced
by optional overtube 47. Overtube 47 serves a similar function to
eyelets 49 by constraining appendages 48 to prevent locking until a
medical practitioner has determined that apparatus of the present
invention has been foreshortened and positioned adequately at a
treatment site. Overtube 47 is then removed, which causes the
appendages to resiliently expand, thereby fully actuating lock
40'''.
[0096] With reference to FIG. 12, an alternative locking mechanism
is described that is configured to engage the patient's aorta. Male
interlocking elements 44'' of locks 40'''' comprise arrowheads 46'
having sharpened appendages 48'. Upon expansion from the delivery
configuration of FIG. 12A to the foreshortened configuration of
FIG. 12B, apparatus 10 positions sharpened appendages 48' adjacent
the patient's aorta A. Appendages 48' engage the aortic wall and
reduce a risk of device migration over time.
[0097] With reference now to FIG. 13, a risk of paravalvular
leakage or regurgitation around apparatus of the present invention
is described. In FIG. 13, apparatus 10 has been implanted at the
site of diseased aortic valve AV, for example, using techniques
described hereinabove. The surface of native valve leaflets L is
irregular, and interface I between leaflets Land anchor 30 may
comprise gaps where blood B may seep through. Such leakage poses a
risk of blood clot formation or insufficient blood flow.
[0098] Referring to FIG. 14, optional elements for reducing
regurgitation or leakage are described. Compliant sacs 200 may be
disposed about the exterior of anchor 30 to provide a more
efficient seal along irregular interface I. Sacs 200 may be filled
with an appropriate material, for example, water, blood, foam or a
hydrogel. Alternative fill materials will be apparent.
[0099] With reference to FIG. 15, illustrative arrangements for
sacs 200 are provided. In FIG. 15A, sacs 200 are provided as
discrete sacs at different positions along the height of anchor 30.
In FIG. 15B, the sacs are provided as continuous cylinders at
various heights. In FIG. 15C, a single sac is provided with a
cylindrical shape that spans multiple heights. The sacs of FIG. 15D
are discrete, smaller and provided in larger quantities. FIG. 15E
provides a spiral sac. Alternative sac configurations will be
apparent to those of skill in the art.
[0100] With reference to FIG. 16, exemplary techniques for
fabricating sacs 200 are provided. In FIG. 16A, sacs 20 comprise
`fish-scale` slots 202 that may be back-filled, for example, with
ambient blood passing through replacement valve 20. In FIG. 16B,
the sacs comprise pores 204 that may be used to fill the sacs. In
FIG. 16C, the sacs open to lumen 31 of anchor 30 and are filled by
blood washing past the sacs as the blood moves through apparatus
10.
[0101] FIGS. 17A-B and 18A-B show yet another alternative
embodiment of the anchor lock. Anchor 300 has a plurality of male
interlocking elements 302 having eyelets 304 formed therein. Male
interlocking elements are connected to braided structure 300 by
inter-weaving elements 302 (and 308) or alternatively suturing,
soldering, welding, or connecting with adhesive. Valve commissures
24 are connected to male interlocking elements 302 along their
length. Replacement valve 20 annular base 22 is connected to the
distal end 34 of anchor 300 (or 30) as is illustrated in Figures IA
and 1B. Male interlocking elements 302 also include holes 306 that
mate with tabs 310 extending into holes 312 in female interlocking
elements 308. To lock, control wires 314 passing through eyelets
304 and holes 312 are pulled proximally with respect to the
proximal end of braided anchor 300 to draw the male interlocking
elements through holes 312 so that tabs 310 engage holes 306 in
male interlocking elements 302. Also shown is release wires 314B
that passes through eyelet 304B in female interlocking element 308.
If needed, during the procedure, the user may pull on release wires
314B reversing orientation of tabs 310 releasing the anchor and
allowing for repositioning of the device or it's removal from the
patient. Only when final positioning as desired by the operating
physician, would release wire 314B and control wire 314 are cut and
removed from the patient with the delivery system.
[0102] FIGS. 19-21 show an alternative way of releasing the
connection between the anchor and its actuating tubes and control
wires. Control wires 62 extend through tubes 60 from outside the
patient, loop through the proximal region of anchor 30 and extend
partially back into tube 60. The doubled up portion of control wire
62 creates a force fit within tube 60 that maintains the control
wire's position with respect to tube 60 when all control wires 62
are pulled proximally to place a proximally directed force on
anchor 30. When a single control wire 62 is pulled proximally,
however, the frictional fit between that control wire and the tube
in which it is disposed is overcome, enabling the end 63 of control
wire 62 to pull free of the tube, as shown in FIG. 21, thereby
releasing anchor 30.
[0103] FIGS. 22-24 show an alternative embodiment of the anchor.
Anchor 350 is made of a metal braid, such as Nitinol or stainless
steel. A replacement valve 354 is disposed within anchor 350.
Anchor 350 is actuated in substantially the same way as anchor 30
of FIGS. 1-4 through the application of proximally and distally
directed forces from control wires (not shown) and tubes 352.
[0104] FIGS. 25 and 26 show yet another embodiment of the delivery
and deployment apparatus of the invention. As an alternative to the
balloon expansion method described with respect to FIG. 8, in this
embodiment the nosecone (e.g., element 102 of FIG. 5) is replaced
by an angioplasty balloon catheter 360. Thus, angioplasty balloon
catheter 360 precedes sheath 110 on guidewire G. When anchor 30 and
valve 20 are expanded through the operation of tubes 60 and the
control wires (not shown) as described above, balloon catheter 360
is retracted proximally within the expanded anchor and valve and
expanded further as described above with respect to FIG. 8.
[0105] FIGS. 27-31 show seals 370 that expand over time to seal the
interface between the anchor and valve and the patient's tissue.
Seals 370 are preferably formed from Nitinol wire surrounded by an
expandable foam. As shown in cross-section in FIGS. 28 and 29, at
the time of deployment, the foam 372 is compressed about the wire
374 and held in the compressed form by a time-released coating 376.
After deployment, coating 376 dissolves in vivo to allow foam 372
to expand, as shown in FIGS. 30 and 31.
[0106] FIGS. 32-34 show another way to seal the replacement valve
against leakage. A fabric seal 380 extends from the distal end of
valve 20 and back proximally over anchor 30 during delivery. When
deployed, as shown in FIGS. 33 and 34, fabric seal 380 bunches up
to create fabric flaps and pockets that extend into spaces formed
by the native valve leaflets 382, particularly when the pockets are
filled with blood in response to backflow blood pressure. This
arrangement creates a seal around the replacement valve.
[0107] FIGS. 35A-H show another embodiment of a replacement heart
valve apparatus in accordance with the present invention. Apparatus
450 comprises replacement valve 460 (see FIGS. 37B and 38C)
disposed within and coupled to anchor 470. Replacement valve 460 is
preferably biologic, e.g. porcine, but alternatively may be
synthetic. Anchor 470 preferably is fabricated from self-expanding
materials, such as a stainless steel wire mesh or a nickel-titanium
alloy ("Nitinol"), and comprises lip region 472, skirt region 474,
and body regions 476a, 476b and 476c. Replacement valve 460
preferably is coupled to skirt region 474, but alternatively may be
coupled to other regions of the anchor. As described hereinbelow,
lip region 472 and skirt region 474 are configured to expand and
engage/capture a patient's native valve leaflets, thereby providing
positive registration, reducing paravalvular regurgitation,
reducing device migration, etc.
[0108] As seen in FIG. 35A, apparatus 450 is collapsible to a
delivery configuration, wherein the apparatus may be delivered via
delivery system 410. Delivery system 410 comprises sheath 420
having lumen 422, as well as wires 424a and 424b seen in FIGS.
35D-35G. Wires 424a are configured to expand skirt region 474 of
anchor 470, as well as replacement valve 460 coupled thereto, while
wires 424b are configured to expand lip region 472.
[0109] As seen in FIG. 35B, apparatus 450 may be delivered and
deployed from lumen 422 of catheter 420 while the apparatus is
disposed in the collapsed delivery configuration. As seen in FIGS.
35B-35D, catheter 420 is retracted relative to apparatus 450, which
causes anchor 470 to dynamically self-expand to a partially
deployed configuration. Wires 424a are then retracted to expand
skirt region 474, as seen in FIGS. 35E and 35F. Preferably, such
expansion may be maintained via locking features described
hereinafter.
[0110] In FIG. 35G, wires 424b are retracted to expand lip region
472 and fully deploy apparatus 450. As with skirt region 474,
expansion of lip region 472 preferably may be maintained via
locking features. After both lip region 472 and skirt region 474
have been expanded, wires 424 may be removed from apparatus 450,
thereby separating delivery system 410 from the apparatus. Delivery
system 410 then may be removed, as seen in FIG. 35H.
[0111] As will be apparent to those of skill in the art, lip region
472 optionally may be expanded prior to expansion of skirt region
474. As yet another alternative, lip region 472 and skirt region
474 optionally may be expanded simultaneously, in parallel, in a
step-wise fashion or sequentially. Advantageously, delivery of
apparatus 450 is fully reversible until lip region 472 or skirt
region 474 has been locked in the expanded configuration.
[0112] With reference now to FIGS. 36A-E, individual cells of
anchor 470 of apparatus 450 are described to detail deployment and
expansion of the apparatus. In FIG. 36A, individual cells of lip
region 472, skirt region 474 and body regions 476a, 476b and 476c
are shown in the collapsed delivery configuration, as they would
appear while disposed within lumen 422 of sheath 420 of delivery
system 410 of FIG. 35. A portion of the cells forming body regions
476, for example, every `nth` row of cells, comprises locking
features.
[0113] Body region 476a comprises male interlocking element 482 of
lip lock 480, while body region 476b comprises female interlocking
element 484 of lip lock 480. Male element 482 comprises eyelet 483.
Wire 424b passes from female interlocking element 484 through
eyelet 483 and back through female interlocking element 484, such
that there is a double strand of wire 424b that passes through
lumen 422 of catheter 420 for manipulation by a medical
practitioner external to the patient. Body region 476b further
comprises male interlocking element 492 of skirt lock 490, while
body region 476c comprises female interlocking element 494 of the
skirt lock. Wire 424a passes from female interlocking element 494
through eyelet 493 of male interlocking element 492, and back
through female interlocking element 494. Lip lock 480 is configured
to maintain expansion of lip region 472, while skirt lock 490 is
configured to maintain expansion of skirt region 474.
[0114] In FIG. 36B, anchor 470 is shown in the partially deployed
configuration, e.g., after deployment from lumen 422 of sheath 420.
Body regions 476, as well as lip region 472 and skirt region 474,
self-expand to the partially deployed configuration. Full
deployment is then achieved by retracting wires 424 relative to
anchor 470, and expanding lip region 472 and skirt region 474
outward, as seen in FIGS. 36C and 36D. As seen in FIG. 36E,
expansion continues until the male elements engage the female
interlocking elements of lip lock 480 and skirt lock 490, thereby
maintaining such expansion (lip lock 480 shown in FIG. 36E).
Advantageously, deployment of apparatus 450 is fully reversible
until lip lock 480 and/or skirt lock 490 has been actuated.
[0115] With reference to FIGS. 37A-B, isometric views, partially in
section, further illustrate apparatus 450 in the fully deployed and
expanded configuration. FIG. 37A illustrates the wireframe
structure of anchor 470, while FIG. 37B illustrates an embodiment
of anchor 470 covered in a biocompatible material B. Placement of
replacement valve 460 within apparatus 450 may be seen in FIG. 37B.
The patient's native valve is captured between lip region 472 and
skirt region 474 of anchor 470 in the fully deployed configuration
(see FIG. 38B).
[0116] Referring to FIGS. 38A-C, in conjunction with FIGS. 35 and
36, a method for endovascularly replacing a patient's diseased
aortic valve with apparatus 450 is described. Delivery system 410,
having apparatus 450 disposed therein, is endovascularly advanced,
preferably in a retrograde fashion, through a patient's aorta A to
the patient's diseased aortic valve AV. Sheath 420 is positioned
such that its distal end is disposed within left ventricle LV of
the patient's heart H. As described with respect to FIG. 35,
apparatus 450 is deployed from lumen 422 of sheath 420, for
example, under fluoroscopic guidance, such that skirt section 474
is disposed within left ventricle LV, body section 476b is disposed
across the patient's native valve leaflets L, and lip section 472
is disposed within the patient's aorta A. Advantageously, apparatus
450 may be dynamically repositioned to obtain proper alignment with
the anatomical landmarks. Furthermore, apparatus 450 may be
retracted within lumen 422 of sheath 420 via wires 424, even after
anchor 470 has dynamically expanded to the partially deployed
configuration, for example, to abort the procedure or to reposition
sheath 420.
[0117] Once properly positioned, wires 424a are retracted to expand
skirt region 474 of anchor 470 within left ventricle LV. Skirt
region 474 is locked in the expanded configuration via skirt lock
490, as previously described with respect to FIG. 36. In FIG. 38A,
skirt region 474 is maneuvered such that it engages the patient's
valve annulus An and/or native valve leaflets L, thereby providing
positive registration of apparatus 450 relative to the anatomical
landmarks.
[0118] Wires 424b are then actuated external to the patient in
order to expand lip region 472, as previously described in FIG. 35.
Lip region 472 is locked in the expanded configuration via lip lock
480. Advantageously, deployment of apparatus 450 is fully
reversible until lip lock 480 and/or skirt lock 490 has been
actuated. Wires 424 are pulled from eyelets 483 and 493, and
delivery system 410 is removed from the patient. As will be
apparent, the order of expansion of lip region 472 and skirt region
474 may be reversed, concurrent, etc.
[0119] As seen in FIG. 38B, lip region 472 engages the patient's
native valve leaflets L, thereby providing additional positive
registration and reducing a risk of lip region 472 blocking the
patient's coronary ostia 0. FIG. 38C illustrates the same in
cross-sectional view, while also showing the position of
replacement valve 460. The patient's native leaflets are engaged
and/or captured between lip region 472 and skirt region 474.
Advantageously, lip region 472 precludes distal migration of
apparatus 450, while skirt region 474 precludes proximal migration.
It is expected that lip region 472 and skirt region 474 also will
reduce paravalvular regurgitation.
* * * * *