U.S. patent application number 11/638473 was filed with the patent office on 2007-06-21 for adjustable prosthetic valve implant.
This patent application is currently assigned to Micardia Corporation. Invention is credited to Jay A. Lenker, Shawn Moaddeb, Samuel Shaolian, Emanuel Shaoulian.
Application Number | 20070142907 11/638473 |
Document ID | / |
Family ID | 38174735 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070142907 |
Kind Code |
A1 |
Moaddeb; Shawn ; et
al. |
June 21, 2007 |
Adjustable prosthetic valve implant
Abstract
A prosthetic implant for treating a diseased aortic valve is
described. The prosthetic implant includes a substantially tubular
body configured to be positioned in an aorta of a patient, at or
near the patient's aortic valve. The body includes a lumen
extending through the body from a proximal end to a distal end of
the body; and an adjustable frame surrounding the lumen. The
prosthetic implant further includes at least one adjustable element
located in or on the body and extending at least partially around a
circumference of the lumen. The at least one adjustable element
includes a shape memory material and is transformable, in response
to application of an activation energy, from a first configuration
to a second configuration, wherein the first configuration and
second configuration differ in a size of at least one dimension of
the at least one adjustable element. The at least one adjustable
element may engage at least one of a root of the aorta, an annulus
of the aortic valve, and the patient's left ventricle, when the at
least one adjustable element is in the second configuration.
Inventors: |
Moaddeb; Shawn; (Irvine,
CA) ; Shaolian; Samuel; (Newport Beach, CA) ;
Shaoulian; Emanuel; (Newport Beach, CA) ; Lenker; Jay
A.; (Laguna Beach, CA) |
Correspondence
Address: |
MCDERMOTT WILL & EMERY LLP
18191 VON KARMAN AVE.
SUITE 500
IRVINE
CA
92612-7108
US
|
Assignee: |
Micardia Corporation
Irvine
CA
|
Family ID: |
38174735 |
Appl. No.: |
11/638473 |
Filed: |
December 14, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60751036 |
Dec 16, 2005 |
|
|
|
Current U.S.
Class: |
623/2.11 ;
623/1.18; 623/2.18; 623/2.37 |
Current CPC
Class: |
A61F 2210/0023 20130101;
A61F 2220/0016 20130101; A61F 2/2469 20130101; A61F 2250/001
20130101; A61F 2220/0058 20130101; A61F 2/2445 20130101; A61F
2250/0007 20130101; A61F 2250/0004 20130101; A61F 2/90 20130101;
A61F 2/07 20130101; A61F 2230/0078 20130101; A61F 2/2418 20130101;
A61F 2002/075 20130101; A61F 2220/0008 20130101; A61F 2220/005
20130101 |
Class at
Publication: |
623/002.11 ;
623/002.37; 623/001.18; 623/002.18 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A prosthetic implant, for treating a diseased aortic valve,
comprising: a substantially tubular body configured to be
positioned in an aorta of a patient, at or near the patient's
aortic valve, the body comprising: a lumen extending through the
body from a proximal end to a distal end of the body; and an
adjustable frame surrounding the lumen; and at least one adjustable
element located in or on the body and extending at least partially
around a circumference of the lumen; wherein the at least one
adjustable element comprises a shape memory material and is
transformable, in response to application of an activation energy,
from a first configuration to a second configuration, wherein the
first configuration and second configuration differ in a size of at
least one dimension of the at least one adjustable element; and
wherein the at least one adjustable element is configured to engage
at least one of a root of the aorta, an annulus of the aortic
valve, and the patient's left ventricle, when the at least one
adjustable element is in the second configuration.
2. The prosthetic implant of claim 1, wherein the at least one
adjustable element is coupled to at least one prosthetic aortic
valve leaflet.
3. The prosthetic implant of claim 1, wherein the at least one
adjustable element comprises a prosthetic aortic valve annulus.
4. The prosthetic implant of claim 1, wherein the shape memory
material is selected from the group consisting of shape memory
metals, shape memory alloys, shape memory polymers, shape memory
ferromagnetic alloys, and combinations thereof.
5. The prosthetic implant of claim 4, wherein the shape memory
material comprises nitinol.
6. The prosthetic implant of claim 1, wherein the at least one
dimension of the second configuration is greater than the at least
one dimension of the first configuration.
7. The prosthetic implant of claim 1, wherein the at least one
dimension of the second configuration is less than the at least one
dimension of the first configuration.
8. The prosthetic implant of claim 6, wherein the at least one
dimension is a diameter.
9. The prosthetic implant of claim 6, wherein the at least one
dimension is a length.
10. The prosthetic implant of claim 1, wherein the at least one
adjustable element is disposed in proximity to the open end of at
least one of the distal end and the proximal end.
11. The prosthetic implant of claim 10, wherein a graft member
covers at least a portion of at least one of the at least one
adjustable element and the body.
12. The prosthetic implant of claim 10, further comprising at least
a second adjustable element disposed between the distal end and the
proximal end.
13. The prosthetic implant of claim 1, wherein the frame comprises
the at least one adjustable element.
14. The prosthetic implant of claim 1, wherein the frame is
expandable.
15. The prosthetic implant of claim 1, wherein the adjustable
element comprises a closed ring.
16. The prosthetic implant of claim 15, wherein the closed ring
comprises a one-way ratchet.
17. The prosthetic implant of claim 1, wherein the adjustable
element comprises an open ring.
18. The prosthetic implant of claim 17, wherein the adjustable
element comprises a spiral portion.
19. The prosthetic implant of claim 1, wherein an insulating layer
is disposed on at least a portion of the shape memory material.
20. The prosthetic implant of claim 19, wherein portions of the
shape memory material are exposed through openings in the
insulating layer.
21. The prosthetic implant of claim 1, wherein an energy-absorbing
material is disposed on at least a portion of the shape memory
material.
22. The prosthetic implant of claim 21, wherein the energy
absorbing material absorbs ultrasonic energy.
23. The prosthetic implant of claim 21, wherein the energy
absorbing material absorbs radio frequency energy.
24. The prosthetic implant of claim 1, wherein the adjustable
element comprises wherein a wire loop that at least partially
surrounds around a portion of the shape memory material.
25. The prosthetic implant of claim 1, wherein a check valve is
affixed to a central region of the body.
26. The prosthetic implant of claim 25, wherein the check valve is
a tri-leaflet check valve.
27. The prosthetic implant of claim 1, further comprising an
activation post configured to transmit activation energy to the at
least one adjustable element.
28. The prosthetic implant of claim 1, further comprising a crown
support.
29. A prosthetic implant for treating a diseased valve in a
patient's aorta, the prosthetic implant comprising: valve means for
permitting one-way flow of blood from the patient's left ventricle
into the aorta; engagement means for engaging at least one of a
root of the aorta, an annulus of the aortic valve, and the
patient's left ventricle, the engagement means being coupled to the
valve means; support means for supporting the valve means and
coupled to the valve means, the support means being configured to
extend distally into the ascending aorta beyond the aortic valve
annulus when the valve means is in position at the aortic valve;
wherein the engagement means is adjustable from a first
configuration to a second configuration in response to an
activation energy established using an energy source external to
the patient's body, wherein the first configuration and second
configuration differ in size in at least one dimension; and wherein
the engagement means engages the at least one of the root of the
aorta, the annulus of the aortic valve, and the patient's left
ventricle, when in the second configuration.
30. A method, for treating an abdominal aortic aneurysm,
comprising: providing a prosthetic implant, comprising: a
substantially tubular body configured to be positioned in an aorta
of a patient, at or near the patient's aortic valve, the body
comprising: a lumen extending through the body from a proximal end
to a distal end of the body; and an adjustable frame surrounding
the lumen; and at least one adjustable element located in or on the
body and extending at least partially around a circumference of the
lumen; wherein the at least one adjustable element comprises a
shape memory material and is transformable, in response to
application of an activation energy, from a first configuration to
a second configuration, wherein the first configuration and second
configuration differ in a size of at least one dimension of the at
least one adjustable element; and wherein the at least one
adjustable element is configured to engage at least one of a root
of the aorta, an annulus of the aortic valve, and the patient's
left ventricle, when the at least one adjustable element is in the
second configuration; and exposing the device to the activation
energy, changing the at least one adjustable element from the first
configuration to the second configuration.
31. The method of claim 30, further comprising implanting the
prosthetic implant at the aortic valve region percutaneously.
32. The method of claim 31, wherein the implanting comprises
expanding at least a portion of the prosthetic implant using a
balloon.
33. The method of claim 30, wherein the device is exposed to the
activation energy post-implantation.
34. The method of claim 31, wherein the device is exposed to an
activation energy in multiple procedures.
35. The method of claim 30, wherein the activation energy comprises
radio frequency energy.
36. The method of claim 30, wherein the activation energy comprises
ultrasound energy.
37. The method of claim 30, wherein the activation energy comprises
magnetic energy.
38. The method of claim 30, wherein the at least one adjustable
element is imaged contemporaneously with exposure to the activation
energy.
39. A catheter device for activating an adjustable implant, the
catheter device comprising: an elongate body having a proximal end
and a distal end, the body configured to be placed within a
patient's heart and/or aorta; a first slot member, having a first
slot, the first slot member disposed at the distal end of the body;
an energy-transfer member configured to couple to an activation
post on a valve implant when the implant is located in the heart
and the activation post is positioned at least partially within the
slot member; at least one activation lead configured to provide a
transfer of energy between an energy source located outside of the
patient and the energy-transfer member.
40. The adjustment catheter of claim 39, wherein the
energy-transfer member is configured to thermally couple to the
activation post.
41. The adjustment catheter of claim 39, wherein the energy source
is coupled to the proximal end of the catheter system.
42. The adjustment catheter of claim 39, wherein the first slot
member further comprises a sharp edge configured to cut through
tissue on the activation post.
43. The adjustment catheter of claim 39, further comprising a
second slot member, having a second slot, wherein the second slot
is disposed at or near the distal end of the body.
44. The adjustment catheter of claim 39, further comprising a
locking member for securely coupling the activation post with the
body.
45. The adjustment catheter of claim 39, further comprising a
spring-loaded tab within the slot or opening.
46. The adjustment catheter of claim 39, further comprising
radiopaque markers.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. .sctn.
119(e) of U.S. Provisional Patent Application No. 60/751,036, filed
on Dec. 16, 2005, and titled "ADJUSTABLE PROSTHETIC VALVE IMPLANT,"
the entirety of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to methods and devices for
reinforcing dysfunctional heart valves and other body structures.
More specifically, embodiments of the present invention relates to
using an aortic valve prosthesis to treat a diseased aortic valve
annulus.
[0004] 2. Description of the Related Art
[0005] The circulatory system of mammals includes the heart and the
interconnecting vessels throughout the body that include both veins
and arteries. The human heart includes four chambers, which are the
left and right atrium and the left and right ventricles. The mitral
valve, which allows blood flow in one direction, is positioned
between the left ventricle and left atrium. The tricuspid valve is
positioned between the right ventricle and the right atrium. The
aortic valve is positioned between the left ventricle and the
aorta, and the pulmonary valve is positioned between the right
ventricle and pulmonary artery. The heart valves function in
concert to move blood throughout the circulatory system. The right
ventricle pumps oxygen-poor blood from the body to the lungs and
then into the left atrium. From the left atrium, the blood is
pumped into the left ventricle and then out the aortic valve into
the aorta. The blood is then recirculated throughout the tissues
and organs of the body and returns once again to the right
atrium.
[0006] If the valves of the heart do not function properly, due
either to disease or congenital defects, the circulation of the
blood may be compromised. Diseased heart valves may be stenotic,
wherein the valve does not open sufficiently to allow adequate
forward flow of blood through the valve, and/or incompetent,
wherein the valve does not close completely. Incompetent heart
valves cause regurgitation or excessive backward flow of blood
through the valve when the valve is closed. For example, certain
diseases of the heart valves can result in dilation of the heart
and one or more heart valves. When a heart valve annulus dilates,
the valve leaflet geometry deforms and causes ineffective closure
of the valve leaflets. The ineffective closure of the valve can
cause regurgitation of the blood, accumulation of blood in the
heart, and other problems.
[0007] Aortic stenosis and aortic regurgitation are common diseases
in an aging population. An effective therapy for these conditions
is aortic valve replacement, in which damaged leaflets are excised
and the diseased valve is sculpted to receive a replacement valve.
Aortic valve replacement is usually accomplished by a surgical
procedure, although endovascular procedures for valve replacement
are an alternative. One endovascular procedure, percutaneous aortic
valve replacement, is becoming a reality and brings new hope for a
number of patients who cannot currently be treated with traditional
surgical techniques.
[0008] Although surgical valve replacement concerns about 200,000
patients worldwide every year, it is estimated that up to two
thirds of these patients do not receive surgery due to either
excessive risk factors and comorbidities or patient refusal due to
fear of lifestyle changes following heavy surgery in elderly
patients. The size of this untreated population is expected to
increase because of the aging population. Without replacing the
valve, aortic stenosis is associated with a very high mortality
rate (50 to 60% at one year) beyond the onset of symptoms. A
percutaneous valve may bring a less invasive therapeutic solution
for these patients.
[0009] Although a number of minimally invasive techniques for
replacing heart valves do exist, they are often problematic. For
example, with many minimally invasive valve replacements,
paravalvular leaks can occur, with moderate to severe leakage
occurring in 25% of cases. Paravalvular leakage may be due to
sub-optimal implant size, shape, location, and the amount of
morphology or calcification. These calcified lesions are extremely
difficult to remove without fragmentation and without leaving some
pieces of calcium, which may migrate and embolize. Accurate and
secure deployment of the valve prostheses will remain a significant
issue for these endovascular procedures.
[0010] The amount of reshaping or adjustment of the implants is
important in these procedures. Excessive oversizing could cause
reshaping of the valve annulus, but could reduce the likelihood of
paravalvular leaks. The resultant paravalvular leak is somewhat
unpredictable at the time of the implantation.
SUMMARY OF THE INVENTION
[0011] A need, therefore, remains for improved technology, which
allows a device to be transluminally introduced, advanced into the
region of the cardiac valve annulus, and implanted over the
pathological natural valve. In certain embodiments, the device
would be able to be guided by fluoroscopy, MRI or ultrasound.
Certain embodiments would further allow for adjustment in size
should perivalvular or paravalvular leakage be detected. Certain
embodiments would further possess the capability for adjustment,
both radially inward and radially outward, using non-surgical
methodology.
[0012] In one embodiment, a prosthetic implant for treating a
diseased aortic valve is disclosed. The prosthetic implant
comprises a substantially tubular body configured to be positioned
in an aorta of a patient, at or near the patient's aortic valve.
The body comprises a lumen extending through the body from a
proximal end to a distal end of the body; and an adjustable frame
surrounding the lumen. The prosthetic implant further comprises at
least one adjustable element located in or on the body and
extending at least partially around a circumference of the lumen.
The at least one adjustable element comprises a shape memory
material and is transformable, in response to application of an
activation energy, from a first configuration to a second
configuration, wherein the first configuration and second
configuration differ in a size of at least one dimension of the at
least one adjustable element. The at least one adjustable element
is configured to engage at least one of a root of the aorta, an
annulus of the aortic valve, and the patient's left ventricle, when
the at least one adjustable element is in the second
configuration.
[0013] In certain embodiments, the at least one adjustable element
is coupled to at least one prosthetic aortic valve leaflet. In
certain embodiments, the at least one adjustable element comprises
a prosthetic aortic valve annulus. In certain embodiments, the
shape memory material is selected from the group consisting of
shape memory metals, shape memory alloys, shape memory polymers,
shape memory ferromagnetic alloys, and combinations thereof. In
certain embodiments, the shape memory material comprises nitinol.
In certain embodiments, the at least one dimension of the second
configuration is greater than the at least one dimension of the
first configuration. In certain embodiments, the at least one
dimension of the second configuration is less than the at least one
dimension of the first configuration. In certain embodiments, the
at least one dimension is a diameter. In certain embodiments, the
at least one dimension is a length. In certain embodiments, the at
least one adjustable element is disposed in proximity to the open
end of at least one of the distal end and the proximal end. In
certain embodiments, a graft member covers at least a portion of at
least one of the at least one adjustable element and the body. In
certain embodiments, the implant further comprises at least a
second adjustable element disposed between the distal end and the
proximal end. In certain embodiments, the frame comprises the at
least one adjustable element. In certain embodiments, the frame is
expandable. In certain embodiments, the adjustable element
comprises a closed ring. The closed ring may comprise a one-way
ratchet. In certain embodiments, the adjustable element comprises
an open ring. In certain embodiments, the adjustable element
comprises a spiral portion. In certain embodiments, an insulating
layer is disposed on at least a portion of the shape memory
material. In certain embodiments, portions of the shape memory
material are exposed through openings in the insulating layer. In
certain embodiments, an energy-absorbing material is disposed on at
least a portion of the shape memory material. In certain
embodiments, the energy absorbing material absorbs ultrasonic
energy. In certain embodiments, the energy absorbing material
absorbs radio frequency energy. In certain embodiments, the
adjustable element comprises wherein a wire loop that at least
partially surrounds around a portion of the shape memory material.
In certain embodiments, a check valve is affixed to a central
region of the body. In certain embodiments, the check valve is a
tri-leaflet check valve. In certain embodiments, the prosthetic
implant further comprises an activation post configured to transmit
activation energy to the at least one adjustable element. In
certain embodiments, the prosthetic implant further comprises a
crown support.
[0014] In one embodiment, a prosthetic implant for treating a
diseased valve in a patient's aorta is disclosed. The prosthetic
implant comprises valve means for permitting one-way flow of blood
from the patient's left ventricle into the aorta. The prosthetic
implant further comprises engagement means for engaging at least
one of a root of the aorta, an annulus of the aortic valve, and the
patient's left ventricle, the engagement means being coupled to the
valve means. The prosthetic implant further comprises support means
for supporting the valve means and coupled to the valve means, the
support means being configured to extend distally into the
ascending aorta beyond the aortic valve annulus when the valve
means is in position at the aortic valve. The engagement means is
adjustable from a first configuration to a second configuration in
response to an activation energy established using an energy source
external to the patient's body, wherein the first configuration and
second configuration differ in size in at least one dimension. The
engagement means engages the at least one of the root of the aorta,
the annulus of the aortic valve, and the patient's left ventricle,
when in the second configuration.
[0015] In one embodiment, a method, for treating an abdominal
aortic aneurysm, is disclosed. The method comprises providing a
prosthetic implant. The prosthetic implant comprises a
substantially tubular body configured to be positioned in an aorta
of a patient, at or near the patient's aortic valve. The body
comprises a lumen extending through the body from a proximal end to
a distal end of the body; and an adjustable frame surrounding the
lumen. The prosthetic implant further comprises at least one
adjustable element located in or on the body and extending at least
partially around a circumference of the lumen. The at least one
adjustable element comprises a shape memory material and is
transformable, in response to application of an activation energy,
from a first configuration to a second configuration, wherein the
first configuration and second configuration differ in a size of at
least one dimension of the at least one adjustable element. The at
least one adjustable element is configured to engage at least one
of a root of the aorta, an annulus of the aortic valve, and the
patient's left ventricle, when the at least one adjustable element
is in the second configuration. The method further comprises
exposing the device to the activation energy, changing the at least
one adjustable element from the first configuration to the second
configuration.
[0016] In certain embodiments, the method further comprises
implanting the prosthetic implant at the aortic valve region
percutaneously. In certain embodiments, the implanting comprises
expanding at least a portion of the prosthetic implant using a
balloon. In certain embodiments, the device is exposed to the
activation energy post-implantation. In certain embodiments, the
device is exposed to an activation energy in multiple procedures.
In certain embodiments, the method further comprises the activation
energy comprises radio frequency energy. In certain embodiments,
the activation energy comprises ultrasound energy. In certain
embodiments, the activation energy comprises magnetic energy. In
certain embodiments, the at least one adjustable element is imaged
contemporaneously with exposure to the activation energy.
[0017] In one embodiment, a catheter device for activating an
adjustable implant is disclosed. The catheter device comprises an
elongate body having a proximal end and a distal end, the body
configured to be placed within a patient's heart and/or aorta. The
catheter device further comprises a first slot member, having a
first slot, the first slot member disposed at the distal end of the
body. The catheter device further comprises an energy-transfer
member configured to couple to an activation post on a valve
implant when the implant is located in the heart and the activation
post is positioned at least partially within the slot member. The
catheter device further comprises at least one activation lead
configured to provide a transfer of energy between an energy source
located outside of the patient and the energy-transfer member.
[0018] In certain embodiments, the energy-transfer member is
configured to thermally couple to the activation post. In certain
embodiments, the energy source is coupled to the proximal end of
the catheter system. In certain embodiments, the first slot member
further comprises a sharp edge configured to cut through tissue on
the activation post. Certain embodiments of the adjustment catheter
further comprise a second slot member, having a second slot,
wherein the second slot is disposed at or near the distal end of
the body. Certain embodiments of the adjustment catheter further
comprise a locking member for securely coupling the activation post
with the body. Certain embodiments of the adjustment catheter
further comprise a spring-loaded tab within the slot or opening.
Certain embodiments of the adjustment catheter further comprise
radiopaque markers.
[0019] For purposes of summarizing the invention, certain aspects,
advantages, and novel features of the invention have been described
herein. It is to be understood that not necessarily all such
advantages may be achieved in accordance with any particular
embodiment of the invention. Thus, the invention may be embodied or
carried out in a manner that achieves or optimizes one advantage or
group of advantages as taught herein without necessarily achieving
other advantages as may be taught or suggested herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A general architecture that implements the various features
of the invention will now be described with reference to the
drawings. The drawings and the associated descriptions are provided
to illustrate embodiments of the invention and not to limit the
scope of the invention. Throughout the drawings, reference numbers
are re-used to indicate correspondence between referenced
elements.
[0021] FIG. 1A illustrates an embodiment of an adjustable
prosthetic valve implant that can be adjusted in vivo after
implantation into a patient's body.
[0022] FIG. 1B illustrates the adjustable prosthetic valve implant
of FIG. 1A in an adjusted state.
[0023] FIG. 1C is a graphical representation of the relationship
between the change in diameter of an embodiment of an adjustable
element and temperature.
[0024] FIG. 1D depicts an adjustable prosthetic valve implant in a
natural aortic valve position.
[0025] FIG. 2A illustrates another embodiment of a prosthetic valve
implant.
[0026] FIG. 2B illustrates the prosthetic valve implant of FIG. 2A
after adjustment.
[0027] FIG. 3A illustrates another embodiment of the prosthetic
valve implant.
[0028] FIG. 3B illustrates the prosthetic valve implant of FIG. 3A
after activation of the central region adjustable ring.
[0029] FIG. 3C illustrates the prosthetic valve implant of FIG. 3A
after activation of all adjustable rings.
[0030] FIG. 4A illustrates another embodiment of the prosthetic
valve implant.
[0031] FIG. 4B illustrates the prosthetic valve implant of FIG. 4A
after activation of adjustable rings located in the central and end
regions of the implant.
[0032] FIG. 5A illustrates another embodiment of the prosthetic
valve implant.
[0033] FIG. 5B illustrates the prosthetic valve implant of FIG. 5A
after activation.
[0034] FIG. 6 illustrates a lateral view, looking along the flow
path, of an embodiment of a prosthetic valve implant having a "D"
shape.
[0035] FIG. 7 illustrates a lateral view, looking along the flow
path, of another embodiment of a prosthetic valve implant having a
"D" shape.
[0036] FIG. 8 illustrates a side view of another embodiment of a
prosthetic valve implant.
[0037] FIG. 9 illustrates a side view of another embodiment of a
prosthetic valve implant.
[0038] FIG. 10A illustrates a first side view of an embodiment of
an unadjusted implant having a "C"-shaped configuration.
[0039] FIG. 10B illustrates a second side view of the C-shaped
implant of FIG. 10A.
[0040] FIG. 11A illustrates a side view of an embodiment of an
unadjusted prosthetic valve implant comprising a three-post crown
support.
[0041] FIG. 11B illustrates a side view of the adjusted implant of
FIG. 11A when activated.
[0042] FIG. 11C illustrates a side view of the implant of FIG. 11A
attached to the central section of the adjustable prosthetic valve
implant of FIG. 1A and deployed in a natural aortic valve
position.
[0043] FIG. 12A illustrates a top view of an embodiment of an
adjustable element comprising an coating layer.
[0044] FIG. 12B illustrates another embodiment of an adjustable
element comprising an coating layer.
[0045] FIG. 12C illustrates a side, partial breakaway view of an
unadjusted implant comprising an energy absorbing coating on its
exterior surface.
[0046] FIG. 13A illustrates a perspective view of an adjustable
element comprising a wire wrapping.
[0047] FIG. 13B illustrates a side, partial breakaway view of an
unadjusted implant comprising a fine wire on the exterior surface
of its outer wall.
[0048] FIG. 14A illustrates a top view of an embodiment of an
adjustable element or ring that is not closed.
[0049] FIG. 14B illustrates the adjustable element of FIG. 14A
after adjustment.
[0050] FIG. 15 illustrates in perspective view an embodiment of an
adjustable prosthetic valve implant comprising the adjustable
element of FIG. 14A.
[0051] FIG. 16A illustrates a top view of an embodiment of an
adjustable element comprising a ratchet.
[0052] FIG. 16B illustrates a top view of another embodiment of an
adjustable element comprising a ratchet.
[0053] FIG. 17A illustrates in perspective view an embodiment of a
spiral adjustable element comprising a groove.
[0054] FIGS. 17B and 17C illustrate steps in the adjustment of the
adjustable element of FIG. 17A.
[0055] FIG. 18A is a cross-section of an embodiment of an
adjustable element in which a shape memory material is disposed in
a recess.
[0056] FIG. 18B illustrates the adjustable element of FIG. 18A
after adjustment.
[0057] FIGS. 19A and 19B illustrate in cross section two
embodiments of adjustable elements with convoluted shape memory
elements.
[0058] FIG. 20A is a cross-section of an another embodiment of an
adjustable element in which a shape memory material is disposed in
a recess.
[0059] FIG. 20B illustrates the adjustable element of FIG. 20A
after adjustment.
[0060] FIG. 21A illustrates an embodiment of an activation post
capable of being attached to an adjustable prosthetic valve
implant.
[0061] FIG. 21B illustrates a distal end of an embodiment of an
adjustment catheter for an adjustable prosthetic valve implant.
[0062] FIG. 22 illustrates a distal end of another embodiment of an
adjustment catheter.
[0063] FIG. 23A illustrates an embodiment of an adjustment post
connected to a prosthetic valve implant.
[0064] FIG. 23B illustrates a distal end of another embodiment of
an adjustment catheter.
[0065] FIG. 24 illustrates an embodiment of a wrappable activation
device.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0066] The invention may be embodied in other specific forms
without departing from its spirit or essential characteristics. The
described embodiments are to be considered in all respects only as
illustrative and not restrictive. The scope of the invention is
therefore indicated by the appended claims rather than the
foregoing description. All changes that come within the meaning and
range of equivalency of the claims are to be embraced within their
scope.
[0067] Embodiments of the present invention involve systems and
methods for reinforcing dysfunctional heart valves and other body
structures with adjustable implants. In certain embodiments, an
adjustable prosthetic valve implant is implanted into the body of a
patient such as a human or other animal. The adjustable prosthetic
valve implant is implanted through an incision or body opening
either thoracically (e.g., open-heart surgery) or percutaneously
(e.g., via a femoral artery or vein, or other arteries or veins) as
is known to someone skilled in the art. The adjustable prosthetic
valve implant can be attached to the annulus of a heart valve, such
as the aortic or mitral valve, to improve leaflet coaptation, to
reduce regurgitation, and/or to reduce stenosis. The prosthetic
valve implant may be selected from one or more shapes comprising a
round or circular shape, an oval shape, a C-shape, a D-shape, a
U-shape, an open circle shape, an open oval shape, and other
curvilinear shapes.
[0068] The size of the prosthetic valve implant can be adjusted
postoperatively to compensate for changes in the size of the heart.
As used herein, the term "postoperatively" refers to a time after
implanting the adjustable prosthetic valve implant and closing the
body opening through which the adjustable prosthetic valve implant
was introduced into the patient's body. For example, the prosthetic
valve implant may be implanted in a child whose heart grows as the
child gets older. Thus, the size of the prosthetic valve implant
may need to be increased. As another example, the size of an
enlarged heart may start to return to its normal size after a
prosthetic valve implant is implanted. Thus, the size of the
prosthetic valve implant may need to be decreased postoperatively
to continue to reinforce the heart valve annulus.
[0069] In certain embodiments, the prosthetic valve implant
comprises a shape memory material that is responsive to changes in
temperature and/or exposure to a magnetic field. Shape memory is
the ability of a material to regain its shape after deformation.
Shape memory materials include polymers, metals, metal alloys and
ferromagnetic alloys. The prosthetic valve implant is adjusted in
vivo by applying an energy source to activate the shape memory
material and cause it to change to a memorized shape. The energy
source may include, for example, thermal energy, radio frequency
(RF) energy, x-ray energy, microwave energy, ultrasonic energy such
as focused ultrasound, high intensity focused ultrasound (HIFU)
energy, light energy, electric field energy, magnetic field energy,
cryogenic energy, combinations of the foregoing, or the like. For
example, one embodiment of electromagnetic radiation that is useful
is infrared energy having a wavelength in a range between
approximately 750 nanometers and approximately 1600 nanometers.
This type of infrared radiation may be produced efficiently by a
solid state diode laser. In certain embodiments, the prosthetic
valve implant is selectively heated using short pulses of energy
having an on and off period between each cycle. The energy pulses
provide segmental heating which allows segmental adjustment of
portions of the prosthetic valve implant without adjusting the
entire implant. In some embodiments, the prosthetic valve implant
has a first activation temperature for expanding its adjustable
elements and a second activation temperature for contracting its
adjustable elements.
[0070] In certain embodiments, the prosthetic valve implant
includes an energy absorbing material to increase heating
efficiency and localize heating in the area of the shape memory
material. Thus, damage to the surrounding tissue is reduced or
minimized. Energy absorbing materials for light or laser activation
energy may include nanoshells, nanospheres and the like,
particularly where infrared laser energy is used to energize the
material. Such nanoparticles may be made from a dielectric, such as
silica, coated with an ultra thin layer of a conductor, such as
gold, and be selectively tuned to absorb a particular frequency of
electromagnetic radiation. In certain such embodiments, the
nanoparticles range in size between about 5 nanometers and about 20
nanometers and can be suspended in a suitable material or solution,
such as saline solution. In certain embodiments, the nanoparticles
range in size between about 2 nanometers and about 30 nanometers.
In certain embodiments, the nanoparticles range in size between
about 5 nanometers and about 20 nanometers. In certain embodiments,
the nanoparticles range in size between about 8 nanometers and
about 15 nanometers. Coatings comprising nanotubes or nanoparticles
can also be used to absorb energy from, for example, HIFU, MRI,
inductive heating, or the like.
[0071] In certain embodiments, thin film deposition or other
coating techniques such as sputtering, reactive sputtering, metal
ion implantation, physical vapor deposition, and chemical
deposition can be used to cover portions or all of the prosthetic
valve implant. Such coatings can be either solid or microporous.
When HIFU energy is used, for example, a microporous structure
traps and directs the HIFU energy toward the shape memory material.
The coating improves thermal conduction and heat removal. In
certain embodiments, the coating also enhances radio-opacity of the
prosthetic valve implant. Coating materials can be selected from
various groups of biocompatible organic or non-organic, metallic or
non-metallic materials such as Titanium Nitride (TiN), Iridium
Oxide (Irox), Carbon, Platinum black, Titanium Carbide (TiC),
Graphite, Ceramic, and other materials used for pacemaker
electrodes or implantable pacemaker leads. Other materials
discussed herein or known in the art can also be used to absorb
energy.
[0072] In certain embodiments, fine conductive wires such as
platinum coated copper, titanium, tantalum, stainless steel, gold,
or the like, are wrapped around the shape memory material to allow
focused and rapid heating of the shape memory material while
reducing undesired heating of surrounding tissues.
[0073] In certain embodiments, the energy source is applied
surgically either during implantation or at a later time. For
example, the shape memory material can be heated during
implantation of the prosthetic valve implant by touching the
prosthetic valve implant with warm object. As another example, the
energy source can be surgically applied after the prosthetic valve
implant has been implanted by percutaneously inserting a catheter
into the patient's body and applying the energy through the
catheter. For example, RF energy, light energy or thermal energy
(e.g., from a heating element using resistance heating) can be
transferred to the shape memory material through a catheter
positioned on or near the shape memory material. Alternatively,
thermal energy can be provided to the shape memory material by
injecting a heated fluid through a catheter or circulating the
heated fluid in a balloon through the catheter placed in close
proximity to the shape memory material. As another example, the
shape memory material can be coated with a photodynamic absorbing
material which is activated to heat the shape memory material when
illuminated by light from a laser diode or directed to the coating
through fiber optic elements in a catheter. In certain such
embodiments, the photodynamic absorbing material includes one or
more drugs that are released when illuminated by the laser
light.
[0074] In certain embodiments, the catheter may be guided to or
coupled with the implant with the assistance of external means. In
certain embodiments, the catheter can have additional sensors or
electrodes to detect physiological or hemodynamic parameters. For
example, the catheter may be capable of detecting pressure,
temperature, ECG, and oxygen saturation. In certain embodiments,
the catheter may comprise imaging capabilities. For example, a
catheter capable of ultrasound imaging may have a built-in
ultrasound transducer and may be linked with ultrasound imaging
equipment. Such a catheter may allow simultaneous therapy and
imaging.
[0075] In certain embodiments, a removable subcutaneous electrode
or coil couples energy from a dedicated activation unit. In certain
such embodiments, the removable subcutaneous electrode provides
telemetry and power transmission between the system and the
prosthetic valve implant. The subcutaneous removable electrode
allows more efficient coupling of energy to the implant with
minimum or reduced power loss. In certain embodiments, the
subcutaneous energy is delivered via inductive coupling.
[0076] In certain embodiments, the energy source is applied in a
non-invasive manner from outside the patient's body. In certain
such embodiments, the external energy source is focused to provide
directional heating to the shape memory material so as to reduce or
minimize damage to the surrounding tissue. For example, in certain
embodiments, a handheld or portable device comprising an
electrically conductive coil generates an electromagnetic field
that non-invasively penetrates the patient's body and induces a
current in the prosthetic valve implant. The current heats the
prosthetic valve implant and causes the shape memory material to
transform to a memorized shape. In certain such embodiments, the
prosthetic valve implant also comprises an electrically conductive
coil wrapped around or embedded in the memory shape material. The
externally generated electromagnetic field induces a current in the
prosthetic valve implant's coil, causing it to heat and transfer
thermal energy to the shape memory material. In certain
embodiments, the prosthetic valve implant includes a coating,
powder, slurry, paste, or combination of the foregoing, that
absorbs energy from the electromagnetic field and transforms the
energy into heat to change the temperature of the shape memory
material. Such coatings may include, for example, a wide variety of
magnetic and non-magnetic mixtures.
[0077] The term "magnetic" as used herein is a broad term and is
used in its ordinary sense and includes, without limitation, any
material that easily magnetizes, such as a material having atoms
that orient their electron spins to conform to an external magnetic
field. A magnetic coating may comprise materials exhibiting
magnetic behavior or that may be magnetized by another magnet,
including, but not limited to, ferromagnetism (including
ferrimagnetism), diamagnetism and paramagnetism.
[0078] In certain embodiments, an external HIFU transducer focuses
ultrasound energy onto the implanted prosthetic valve implant to
heat the shape memory material. In certain such embodiments, the
external HIFU transducer is a handheld or portable device. The
terms "HIFU," "high intensity focused ultrasound" or "focused
ultrasound" as used herein are broad terms and are used at least in
their ordinary sense and include, without limitation, acoustic
energy within a wide range of intensities and/or frequencies. For
example, HIFU includes acoustic energy focused in a region, or
focal zone, having an intensity and/or frequency that is
considerably less than what is currently used for ablation in
medical procedures. Thus, in certain such embodiments, the focused
ultrasound is not destructive to the patient's cardiac tissue. In
certain embodiments, HIFU includes acoustic energy within a
frequency range of approximately 0.5 MHz and approximately 30 MHz
and a power density within a range of approximately 1 W/cm.sup.2
and approximately 500 W/cm.sup.2.
[0079] In certain embodiments, the prosthetic valve implant
comprises an ultrasound absorbing material or hydro-gel material
that allows focused and rapid heating when exposed to the
ultrasound energy and transfers thermal energy to the shape memory
material. In certain embodiments, a HIFU probe is used with an
adaptive lens to compensate for heart and respiration movement. The
adaptive lens has multiple focal point adjustments. In certain
embodiments, a HIFU probe with adaptive capabilities comprises a
phased array or linear configuration. In certain embodiments, an
external HIFU probe comprises a lens configured to be placed
between a patient's ribs to improve acoustic window penetration and
reduce or minimize issues and challenges regarding passing through
bones. In certain embodiments, HIFU energy is synchronized with an
ultrasound imaging device to allow visualization of the prosthetic
valve implant during HIFU activation. In addition, in certain
embodiments, ultrasound imaging is used to non-invasively monitor
the temperature of tissue surrounding the prosthetic valve implant
by using principles of speed of sound shift and changes to tissue
thermal expansion.
[0080] In certain embodiments, non-invasive energy is applied to
the implanted prosthetic valve implant using a Magnetic Resonance
Imaging (MRI) device. In certain such embodiments, the shape memory
material is activated by a constant magnetic field generated by the
MRI device. In addition, in certain embodiments, the MRI device
generates RF pulses that induce current in the prosthetic valve
implant and heat the shape memory material. The prosthetic valve
implant can include one or more coils and/or MRI energy absorbing
material to increase the efficiency and directionality of the
heating. Suitable energy absorbing materials for magnetic
activation energy include particulates of ferromagnetic material.
Suitable energy absorbing materials for RF energy include ferrite
materials as well as other materials configured to absorb RF energy
at resonant frequencies thereof, such as Fe--C, Fe--Pd, Fe--Mn--Si,
Co--Mn, Fe--Co--Ni--Ti, Ni2MnGa, Co--Ni--Al, barium ferrite, barium
boron, and the like.
[0081] In certain embodiments, the MRI device is used to determine
the size of the implanted prosthetic valve implant before, during
and/or after the shape memory material is activated. In certain
such embodiments, the MRI device generates RF pulses at a first
frequency to heat the shape memory material and at a second
frequency to image the implanted prosthetic valve implant. Thus,
the size of the prosthetic valve implant can be measured without
heating the ring. In certain such embodiments, an MRI energy
absorbing material heats sufficiently to activate the shape memory
material when exposed to the first frequency and does not
substantially heat when exposed to the second frequency. Other
imaging techniques known in the art can also be used to determine
the size of the implanted ring including, for example, ultrasound
imaging, computed tomography (CT) scanning, X-ray imaging, or the
like. In certain embodiments, such imaging techniques also provide
sufficient energy to activate the shape memory material.
[0082] In certain embodiments, imaging and resizing of the
prosthetic valve implant is performed as a separate procedure at
some point after the prosthetic valve implant has been surgically
implanted into the patient's heart and the patient's heart,
pericardium and chest have been surgically closed. However, in
certain embodiments, it is advantageous to perform the imaging
after the heart and/or pericardium have been closed, but before
closing the patient's chest, to check for leakage or the amount of
regurgitation. If the amount of regurgitation remains excessive
after the prosthetic valve implant has been implanted, energy from
the imaging device (or from another source as discussed herein) can
be applied to the shape memory material so as to at least partially
contract the prosthetic valve implant and reduce regurgitation to
an acceptable level. Thus, the success of the surgery can be
checked and corrections can be made, if necessary, before closing
the patient's chest.
[0083] In certain embodiments, activation of the shape memory
material is synchronized with the heart beat during an imaging
procedure. For example, an imaging technique can be used to focus
HIFU energy onto a prosthetic valve implant in a patient's body
during a portion of the cardiac cycle. As the heart beats, the
prosthetic valve implant may move in and out of this area of
focused energy. To reduce damage to the surrounding tissue, the
patient's body is exposed to the HIFU energy during portions of the
cardiac cycle that focus the HIFU energy onto the cardiac ring. In
certain embodiments, the energy is gated with a signal that
represents the cardiac cycle such as an electrocardiogram signal.
In certain such embodiments, the synchronization and gating is
configured to allow delivery of energy to the shape memory
materials at specific times during the cardiac cycle to avoid or
reduce the likelihood of causing arrhythmia or fibrillation during
vulnerable periods. For example, the energy can be gated so as to
expose the patient's heart to the energy during the T wave of the
electrocardiogram signal.
[0084] As discussed above, shape memory materials include, for
example, polymers, metals, and metal alloys including ferromagnetic
alloys. Exemplary shape memory polymers that are usable for certain
embodiments of the present invention are disclosed by Langer, et
al. in U.S. Pat. No. 6,720,402, issued Apr. 13, 2004, U.S. Pat. No.
6,388,043, issued May 14, 2002, and U.S. Pat. No. 6,160,084, issued
Dec. 12, 2000, each of which are hereby incorporated by reference
herein. Shape memory polymers respond to changes in temperature by
changing to one or more permanent or memorized shapes. In certain
embodiments, the shape memory polymer is heated to a temperature
between approximately 38 degrees Celsius and approximately 60
degrees Celsius. In certain embodiments, the shape memory polymer
is heated to a temperature in a range between approximately 40
degrees Celsius and approximately 55 degrees Celsius. In certain
embodiments, the shape memory polymer has a two-way shape memory
effect wherein the shape memory polymer is heated to change it to a
first memorized shape and cooled to change it to a second memorized
shape. The shape memory polymer can be cooled, for example, by
inserting or circulating a cooled fluid through a catheter.
[0085] Shape memory polymers implanted in a patient's body can be
heated non-invasively using, for example, external light energy
sources such as infrared, near-infrared, ultraviolet, microwave
and/or visible light sources. The light energy may be selected to
increase absorption by the shape memory polymer and reduce
absorption by the surrounding tissue. Thus, damage to the tissue
surrounding the shape memory polymer is reduced when the shape
memory polymer is heated to change its shape. In certain
embodiments, the shape memory polymer comprises gas bubbles or
bubble containing liquids such as fluorocarbons and is heated by
inducing a cavitation effect in the gas/liquid when exposed to HIFU
energy. In certain embodiments, the shape memory polymer may be
heated using electromagnetic fields and may be coated with a
material that absorbs electromagnetic fields.
[0086] Certain metal alloys have shape memory qualities and respond
to changes in temperature and/or exposure to magnetic fields.
Exemplary shape memory alloys that respond to changes in
temperature include titanium-nickel, copper-zinc-aluminum,
copper-aluminum-nickel, iron-manganese-silicon,
iron-nickel-aluminum, gold-cadmium, combinations of the foregoing,
and the like. In certain embodiments, the shape memory alloy
comprises a biocompatible material such as a titanium-nickel alloy.
Shape memory alloys may comprise binary allow compositions, ternary
allow compositions, or any of their combinations.
[0087] Shape memory alloys exist in two distinct solid phases
called martensite and austenite. The martensite phase is relatively
soft and easily deformed, whereas the austenite phase is relatively
stronger and less easily deformed. For example, shape memory alloys
enter the austenite phase at a relatively high temperature and the
martensite phase at a relatively low temperature. Shape memory
alloys begin transforming to the martensite phase at a start
temperature (M.sub.s) and finish transforming to the martensite
phase at a finish temperature (M.sub.f). Similarly, such shape
memory alloys begin transforming to the austenite phase at a start
temperature (A.sub.s) and finish transforming to the austenite
phase at a finish temperature (A.sub.f). Both transformations have
a hysteresis. Thus, the M.sub.s temperature and the A.sub.f
temperature are not coincident with each other, and the M.sub.f
temperature and the A.sub.s temperature are not coincident with
each other.
[0088] In certain embodiments, the shape memory alloy is processed
to form a memorized shape in the austenite phase in the form of a
ring or partial ring. The shape memory alloy is then cooled below
the M.sub.f temperature to enter the martensite phase and deformed
into a larger or smaller ring. For example, in certain embodiments,
the shape memory alloy is formed into a ring or partial ring that
is larger than the memorized shape but still small enough to
improve leaflet coaptation and reduce regurgitation in a heart
valve upon being attached to the heart valve annulus. In certain
such embodiments, the shape memory alloy is sufficiently malleable
in the martensite phase to allow a user such as a physician to
adjust the circumference of the ring in the martensite phase by
hand to achieve a desired fit for a particular heart valve annulus.
After the ring is attached to the heart valve annulus, the
circumference of the ring can be adjusted non-invasively by heating
the shape memory alloy to an activation temperature (e.g.,
temperatures ranging from the A.sub.s temperature to the A.sub.f
temperature).
[0089] Thereafter, when the shape memory alloy is exposed to a
temperature elevation and transformed to the austenite phase, the
alloy changes in shape from the deformed shape to the memorized
shape. Activation temperatures at which the shape memory alloy
causes the shape of the prosthetic valve implant to change shape
can be selected and built into the prosthetic valve implant such
that collateral damage is reduced or eliminated in tissue adjacent
the prosthetic valve implant during the activation process.
Exemplary A.sub.f temperatures for suitable shape memory alloys
range between approximately 45 degrees Celsius and approximately 70
degrees Celsius. Furthermore, exemplary M.sub.s temperatures range
between approximately 10 degrees Celsius and approximately 20
degrees Celsius, and exemplary M.sub.f temperatures range between
approximately -1 degrees Celsius and approximately 15 degrees
Celsius. The size of the prosthetic valve implant can be changed
all at once or incrementally in small steps at different times in
order to achieve the adjustment necessary to produce the desired
clinical result.
[0090] Certain shape memory alloys may further include a
rhombohedral phase, having a rhombohedral start temperature
(R.sub.s) and a rhombohedral finish temperature (R.sub.f), that
exists between the austenite and martensite phases. An example of
such a shape memory alloy is a NiTi alloy, which is commercially
available from Memry Corporation (Bethel, Conn.). In certain
embodiments, an exemplary R.sub.s temperature range is between
approximately 30 degrees Celsius and approximately 50 degrees
Celsius, and an exemplary R.sub.f temperature range is between
approximately 20 degrees Celsius and approximately 35 degrees
Celsius. One benefit of using a shape memory material having a
rhombohedral phase is that in the rhombohedral phase the shape
memory material may experience a partial physical distortion, as
compared to the generally rigid structure of the austenite phase
and the generally deformable structure of the martensite phase.
[0091] Certain shape memory alloys exhibit a ferromagnetic shape
memory effect wherein the shape memory alloy transforms from the
martensite phase to the austenite phase when exposed to an external
magnetic field. The term "ferromagnetic" as used herein is a broad
term and is used in its ordinary sense and includes, without
limitation, any material that easily magnetizes, such as a material
having atoms that orient their electron spins to conform to an
external magnetic field. Ferromagnetic materials include permanent
magnets, which can be magnetized through a variety of modes, and
materials, such as metals, that are attracted to permanent magnets.
Ferromagnetic materials also include ceramic magnets, which are
electrically non-conductive ferrimagnetic ceramic compound
materials comprising various mixtures of iron oxides such as
Hematite or Magnetite and the oxides of other metals. Ferromagnetic
materials also include electromagnetic materials that are capable
of being activated by an electromagnetic transmitter, such as one
located outside the heart 100. Furthermore, ferromagnetic materials
may include one or more polymer-bonded magnets, wherein magnetic
particles are bound within a polymer matrix, such as a
biocompatible polymer. The magnetic materials can comprise
isotropic and/or anisotropic materials, such as for example NdFeB
(Neodynium Iron Boron), SmCo (Samarium Cobalt), ferrite and/or
AlNiCo (Aluminum Nickel Cobalt) particles.
[0092] Thus, a prosthetic valve implant comprising a ferromagnetic
shape memory alloy can be implanted in a first configuration having
a first shape and later changed to a second configuration having a
second (e.g., memorized) shape without heating the shape memory
material above the A.sub.s temperature. Advantageously, nearby
healthy tissue is not exposed to high temperatures that could
damage the tissue. Further, since the ferromagnetic shape memory
alloy does not need to be heated, the size of the prosthetic valve
implant can be adjusted more quickly and more uniformly than by
heat activation.
[0093] Exemplary ferromagnetic shape memory alloys include Fe--C,
Fe--Pd, Fe--Mn--Si, Co--Mn, Fe--Co--Ni--Ti, Ni--Mn--Ga,
Ni.sub.2MnGa, Co--Ni--Al, and the like. Certain of these shape
memory materials may also change shape in response to changes in
temperature. Thus, the shape of such materials can be adjusted by
exposure to a magnetic field, by changing the temperature of the
material, or both.
[0094] In certain embodiments, combinations of different shape
memory materials are used. For example, prosthetic valve implants
according to certain embodiments comprise a combination of shape
memory polymer and shape memory alloy (e.g., NiTi). In certain such
embodiments, a prosthetic valve implant comprises a shape memory
polymer tube and a shape memory alloy (e.g., NiTi) disposed within
the tube. Such embodiments are flexible and allow the size and
shape of the shape memory to be further reduced without impacting
fatigue properties. In addition, in certain embodiments, shape
memory polymers are used with shape memory alloys to create a
bi-directional (e.g., capable of expanding and contracting)
prosthetic valve implant. Bi-directional prosthetic valve implants
can be created with a wide variety of shape memory material
combinations having different characteristics.
[0095] In the following description, reference is made to the
accompanying drawings, which form a part hereof, and which show, by
way of illustration, specific embodiments or processes in which the
invention may be practiced. Where possible, the same reference
numbers are used throughout the drawings to refer to the same or
like components. In some instances, numerous specific details are
set forth in order to provide a thorough understanding of the
present disclosure. The present disclosure, however, may be
practiced without the specific details or with certain alternative
equivalent components and methods to those described herein. In
other instances, well-known components and methods have not been
described in detail so as not to unnecessarily obscure aspects of
the present disclosure.
[0096] FIG. 1A illustrates an adjustable prosthetic valve implant
100 according to certain embodiments that can be adjusted in vivo
after implantation into a patient's body. The prosthetic valve
implant 100 comprises an axially elongate hollow tubular body
member 110 having a proximal end 126 and a distal end 124. As
defined herein, a location that is defined as proximal is closer to
the user than a location that is defined as distal. The illustrated
embodiment further comprises a deformable or adjustable ring 106 at
its proximal end 126 and a deformable or adjustable ring 104 at its
distal end 124. In certain embodiments, the prosthetic valve
implant 100 comprises an artificial valve.
[0097] The diameters of a catheter or implant are often measured in
"French Size" which can be defined as three times the diameter in
millimeters (mm). For example, a 15 French catheter is five
millimeters in diameter. The French size is designed to approximate
the circumference of the catheter in millimeters and is often
useful for catheters that have non-circular cross-sectional
configurations. Although the original measurement of "French" used
.pi. (3.14159 . . . ) as the conversion factor between diameters in
millimeters and French, the system today uses a conversion factor
of three.
[0098] In the illustrated embodiment, the prosthetic valve implant
100 is substantially symmetrical, that is, the prosthetic valve
implant 100 is substantially similar in outer diameter or
transverse dimension from the distal end of the tubular member 124
to the proximal end 126. As used herein, "dimension" is a broad
term having its ordinary and customary meaning and includes a size
or distance from a first point to a second point along a line or
arc. For example, a dimension may be a circumference, diameter,
radius, arc length, or the like. As another example, a dimension
may be a distance between an anterior portion and a posterior
portion of an annulus. In certain embodiments, the size of the
dimension of an adjustable element or an annulus may be an
intertrigonal length, anteroposterior length, a side-side (lateral)
length, oblique or diagonal length, or other length. In certain
embodiments, the prosthetic valve implant 100 is not
symmetrical.
[0099] The prosthetic valve implant 100 has a longitudinal axis and
has one or more internal lumens that extend from the proximal end
126 to the distal end 124 for the passage of instruments, fluids,
tissue, or other materials. The axially elongate hollow tubular
structure is generally flexible and capable of bending, to a
greater or lesser degree, through one or more arcs in one or more
directions perpendicular to the main longitudinal axis, so as to
facilitate delivery of the implant.
[0100] In certain embodiments, the tubular structure 110 comprises
a graft member 112 and a frame 114. The graft member 112 defines a
lumen through which blood is directed, thereby providing an
unimpeded flow of blood, such as from the heart into the aorta. The
diameters of the lumens under physiological conditions will vary
depending on sizes of the heart and aorta of the patient. The frame
114 provides mechanical support to the prosthetic valve implant
100, and in some embodiments, anchors the implant 100 to at least
some degree. FIG. 1 shows part of the graft member 112 cut away in
order to illustrate the frame 114 of which the implant 100 is
comprised.
[0101] In certain embodiments, the implant 100 comprises an
artificial heart valve (not illustrated). In certain embodiments,
the artificial heart valve may be a mechanical valve. In certain
embodiments, the artificial heart valve may be a biological
(tissue) valve, such as a porcine valve. In certain embodiments,
the artificial heart valve may be a check valve. In certain
embodiments, the artificial heart valve may be another type of
artificial valve. In certain embodiments the artificial heart valve
may be located in a central section of the implant 100. In certain
embodiments, the artificial valve may be located in another section
of the implant.
[0102] In some embodiments, the graft member 112 comprises a graft
fabric that is substantially impermeable to body fluids, for
example, blood and/or plasma. The graft fabric comprises one or
more biocompatible materials known in the art, for example,
polyester (Dacron.RTM.), polyamide (Nylon.RTM., Delrin.RTM.),
polyimide (PI), polyetherimide (PEI), polyetherketone (PEEK),
polyamide-imide (PAI), polyphenylene sulfide (PPS), polysulfone
(PSU), silicone, woven velour, polyurethane,
polytetrafluoroethylene (PTFE, Teflon.RTM.), expanded PTFE (ePTFE),
fluoroethylene propylene (FEP), perfluoralkoxy (PFA),
ethylene-tetrafluoroethylene-copolymer (ETFE, Tefzel.RTM.),
ethylene-chlorotrifluoroethylene (Halar.RTM.),
polychlorotrifluoroethylene (PCTFE), polychlorotrifluoroethylene
(PCTE, Aclar.RTM., Clarus.RTM.), polyvinylfluoride (PVF),
polyvinylidenefluoride (PVDF, Kynar.RTM., Solef.RTM.), fluorinated
polymers, polyethylene (PE, Spectra.RTM.), polypropylene (PP),
ethylene propylene (EP), ethylene vinylacetate (EVA), polyalkenes,
polyacrylates, polyvinylchloride (PVC), polyvinylidenechloride,
polyether block amides (PEBAX), polyaramid (Kevlar.RTM.),
heparin-coated fabric, or the like. In some embodiments, the graft
member 112 comprises reinforcing fibers known in the art, for
example, fibers made from the materials discussed above, as well as
fibers made from metal, steel, stainless steel, NiTi, metal alloys,
carbon, boron, ceramic, polymer, glass, polymers, biopolymers, silk
protein, cellulose, collagen, combinations thereof, and the like.
In certain embodiments, the graft member 112 comprises a biological
material, for example, a homograft, a patient graft, or a
cell-seeded tissue. Combinations and/or composites are also
suitable.
[0103] In some embodiments, the graft fabric comprises a laminate
and/or composite having two or more layers. In some embodiments,
the graft member 112 comprises a laminated graft fabric. In some
embodiments, the laminate comprises one or more biologically active
layers, for example, an inner and/or outer layer conducive to the
proliferation of endothelial tissue, and/or that releases a drug,
therapeutic agent, anti-coagulant, anti-proliferant,
anti-inflammatory agent, and/or tissue growth modulating agent. In
some embodiments, the laminate comprises one or more mechanical
and/or reinforcing layers, comprising, for example, mesh and/or
fabric layers, and/or reinforcing fibers. The fabric layers are
woven or non-woven. Methods for manufacturing laminated/composite
fabrics are known in the art, for example, using adhesives, thermal
bonding, in situ curing, and the like. Those skilled in the art
will understand that such layers for useful for providing the graft
member 112 with desired mechanical properties, for example,
strength, elasticity, and/or the like. For example, in some
embodiments, the graft fabric is elastomeric, thereby permitting
the graft member 112 to expand and contract in response to blood
pressure changes. In some embodiments, the graft member 112 in its
maximally expanded state under physiological conditions is smaller
than the aorta. In some embodiments, the graft member 112 in its
maximally expanded state under physiological conditions is larger
than the aorta. In some embodiments, the mechanical properties of
the graft member 112 are anisotropic. For example, in some
embodiments, the graft member 112 is more expandable
circumferentially than longitudinally.
[0104] In some embodiments, the graft member 112 has a
substantially uniform thickness. In certain embodiments, the graft
member 112 comprises areas of different thicknesses. For example,
some embodiments of a fabric laminate graft member 112 comprise
extra reinforcement in areas subject to stress, for example, where
the graft member 112 is likely to contact the frame 114, and/or
around the ends 124 and 126 of the tubular member 110. In some
embodiments, the graft fabric is from about 0.25 mm to about 2.5 mm
thick. In some embodiments, the graft fabric is from about 0.15 mm
to about 4.0 mm thick. In some embodiments, the graft fabric is
from about 0.05 mm to about 5.0 mm thick.
[0105] The frame 114 is of any suitable type known in the art. In
some embodiments, the frame 114 comprises a metal, for example,
titanium, steel, stainless steel, and/or, nitinol. In some
embodiments, the frame 114 comprises a non-metal, for example, a
polymer or ceramic. The polymer is rigid, flexible, and/or
elastomeric. In some embodiments, the frame 114 comprises a
composite. In some embodiments, the frame 114 is substantially
unitary. In some embodiments, the frame 114 comprises a plurality
of components or subassemblies. In some embodiments, the frame 114
comprises one or more structures and/or subcomponents fabricated
from wire. The term "wire" is a broad term having its normal and
customary meaning and includes, for example, mesh, flat, round,
rod-shaped, or band-shaped members, as well as solid, hollow or
tubular elongated structures that may in cross-section be
cylindrical, elliptical, polygonal, or any other shape, including a
substantially flat ribbon shape. In certain embodiments, the frame
114 comprises shape memory materials, as described above.
[0106] In some embodiments, the frame 114 comprises one or more
structures and/or subcomponents fabricated from a sheet and/or
billet, for example, by stamping, drilling, cutting, forging,
shearing, machining, etching, and the like. In some embodiments,
the frame 114 is at least partially self-deploying. In some
embodiments, a deployment device is used, for example, a balloon.
In certain embodiments, the frame 114 comprises securing means for
securing the implant 100, for example, hooks, barbs, spikes,
protrusions, and the like. The securing means are disposed on the
frame 114 at or around the exterior of the proximal end 126 and
distal end 124. In some embodiments, the frame 114 comprises one or
more biologically active compounds and/or active chemical entities
known in the art, for example, a drug, therapeutic agent,
anti-coagulant, anti-proliferant, anti-inflammatory agent, and/or
tissue growth modulating agent. In the illustrated embodiment, the
frame 114 comprises a stent.
[0107] The illustrated embodiment 100 comprises a plurality of
adjustable elements which, in the illustrated embodiment, are
adjustable rings 104 and 106. Those skilled in the art will
understand that the following description of the adjustable rings
104 and 106 is equally applicable to other types of adjustable
elements. As used, the term "ring" broadly refers to shapes that
are closed or open. In the illustrated embodiment, the adjustable
rings 104 and 106 are substantially circular, closed rings.
[0108] In certain embodiments, the prosthetic valve implant may
comprise additional adjustable rings. For example, in certain
embodiments, the prosthetic valve implant may comprise an
adjustable ring in a location substantially equidistant from the
rings 106 and 104 located at the proximal and distal ends 126 and
124 of the implant 100, respectively.
[0109] In the illustrated embodiment, adjustable rings 106 and 104
are located at the proximal 126 and distal ends 124 of the implant
100, respectively. In some embodiments, one or more of the
adjustable rings are secured to the frame 114, to the graft member
112, or to the frame 114 and the graft member 112. Each of the
adjustable rings 104 and 106 is independently selected from one or
more shapes, for example, a round or circular shape, an oval shape,
a C-shape, a D-shape, a U-shape, an open circle shape, an open oval
shape, other curvilinear shapes, spiral shapes, and other suitable
shapes.
[0110] Each of the adjustable rings 104 and 106 independently have
any suitable cross-sectional shape. In some embodiments, the
adjustable rings 104 and 106 have substantially, circular,
elliptical, ovoid, rectangular, trapezoidal, square, triangular,
and/or hexagonal cross sections. In some embodiments, an adjustable
ring may comprise an adjustable wire. Those skilled in the art will
understand that in some embodiments, the cross sectional shape
assists in the securing of one or more of the adjustable rings 104
and 106 to the body 110, as discussed above. In some embodiments,
one or more of the adjustable rings 104 and 106 comprises means for
securing the implant 100 in the body, for example, hooks, barbs,
spikes, protrusions, and the like.
[0111] The outer diameter of the adjustable rings 104 and 106 is
expandable and/or contractible. In some embodiments, another
dimension of the adjustable rings 104 and 106 is also adjustable,
for example, the length. In some embodiments, the dimensional
change(s) are substantially isotropic, while in some embodiments,
the changes are anisotropic. For example, in some embodiments, a
substantially circular adjustable ring is substantially elliptical
after adjustment.
[0112] The adjustable rings 104 and 106 independently comprise one
or more of the shape memory materials discussed herein, for
example, metals, alloys, polymers, and/or ferromagnetic alloys. In
some embodiments, one or more of the adjustable rings 104 and 106
comprises a shape memory material that responds to the application
of temperature that differs from a nominal ambient temperature, for
example, the nominal body temperature of 37 degrees Celsius for
humans. In some embodiments, the shape memory material is nitinol.
Heating the adjustable ring above the austenite temperature of the
shape memory material induces the adjustable ring to return to the
memorized shape.
[0113] In some embodiments, the adjustable rings 104 and 106 are
expandable. In some embodiments, each of the adjustable rings 104
and 106 has on outer diameter of from about 0.5 cm to about 1.5 cm
in an unadjusted configuration. In some embodiments, each of the
adjustable rings 104 and 106 has on outer diameter of from about 1
cm to about 2 cm in an adjusted configuration. In some embodiments,
the expansion percentages for the adjustable rings 104 and 106 is
from about 6% to about 23%, where the expansion percentage is the
difference between the starting and finishing diameter of the
adjustable ring divided by the starting diameter. In some
embodiments, the expansion percentages for the adjustable rings 104
and 106 is from about 3% to about 35%. Those skilled in the art
will understand that different sized adjustable rings 104 and 106
are useful for different patients, such as adjustable rings with
sizes smaller than 0.25 cm or larger than 1.5 cm.
[0114] The activation temperatures (e.g., temperatures ranging from
the A.sub.s temperature to the A.sub.f temperature) at which an
adjustable element expands to an increased circumference are
selected and built into an adjustable element such that collateral
damage is reduced or eliminated in tissue adjacent the adjustable
element during the activation process. In certain embodiments, the
activation temperatures for shape memory material of an adjustable
element at which substantially maximum expansion occurs are in a
range between about 38 degrees Celsius and about 1310 degrees
Celsius. In some embodiments, the activation temperatures are in a
range between about 39 degrees Celsius and about 75 degrees
Celsius. For some embodiments that include shape memory polymers
for an adjustable element, activation temperatures at which the
glass transition of the material or substantially maximum
contraction occur range between about 38 degrees Celsius and about
60 degrees Celsius. In some embodiments, the activation temperature
is in a range between about 40 degrees Celsius and about 59 degrees
Celsius.
[0115] In some embodiments, the austenite start temperature A.sub.s
is in a range between about 33 degrees Celsius and about 43 degrees
Celsius, the austenite finish temperature A.sub.f is in a range
between about 45 degrees Celsius and about 55 degrees Celsius, the
martensite start temperature M.sub.s, is less than about 30 degrees
Celsius, and the martensite finish temperature M.sub.f is greater
than about 20 degrees Celsius. In some embodiments, the austenite
finish temperature A.sub.f is in a range between about 48.75
degrees Celsius and about 51.25 degrees Celsius. Certain
embodiments can include other start and finish temperatures for
martensite, rhombohedral and austenite phases as described
herein.
[0116] In some embodiments, an adjustable element is shape set in
the austenite phase to a remembered configuration during its
manufacturing such that the remembered configuration has a
relatively larger diameter. After cooling the adjustable element
below the M.sub.f temperature, it is mechanically deformed to a
relatively smaller diameter to achieve a desired starting nominal
diameter. In some embodiments, the adjustable element is
sufficiently malleable in the martensite phase to allow a user,
such as a physician, to manually adjust the circumferential value
to achieve a desired fit the for the appropriate heart valve.
[0117] In some embodiments, one or more of the adjustable rings 104
and 106 comprises a plurality of components. For example, in some
embodiments, an adjustable ring 104 and 106 comprises a body and a
means for securing the ring to the body 110, for example, screws,
pins, a lock ring, a snap ring, latches, detents, springs, clips,
combinations thereof, and the like. In some embodiments, one or
more of the adjustable rings 104 and 106 comprise a plurality of
shape memory materials, each of which is adjustable under different
conditions. For example, in some embodiments, an adjustable element
comprises a plurality of shape memory materials with different
A.sub.f temperatures, thereby permitting a stepwise and/or
sequential adjustment of the adjustable element using selective
heating and/or cooling, as discussed below. In some embodiments, an
adjustable element comprises two or more shape memory materials
that adjust by different mechanisms, for example, a thermal shape
memory material and a ferromagnetic shape memory material.
[0118] In the illustrated embodiment, the adjustable rings 104 and
106 are secured to both the graft member 112 and the frame 114 by
means known in the art, for example, by suturing, adhesively,
mechanically, manufacturing integrally into the body 110, thermal
welding and/or bonding, or combinations thereof. Examples of
suitable adhesives are known in the art, and include polyurethane,
polyurea, epoxide, synthetic rubbers, silicone, and mixtures,
blends, and copolymers thereof. The adhesive(s) may be UV curing,
thermally curing, thermoplastic, and/or thermosetting. Suitable
mechanical securing means include lock rings, snap rings, pins,
screws, latches, detents, springs, clips, swaging, heat shrinking,
and the like. Thermal welding or bonding is performed with or
without an intermediate bonding layer, for example, a thermoplastic
bonding film (e.g., polyethylene, polychlorotrifluoroethylene,
and/or fluoroethylene propylene). In some embodiments, at least one
of the adjustable rings 104 and 106 is integral with at least a
portion of the frame 114, for example, formed in the same
manufacturing step. In some embodiments, at least one of the
adjustable rings 104 and 106 is secured to at least a portion of
the frame 114 as discussed above.
[0119] In some embodiments, at least one of the adjustable rings
104 and 106 comprises a porous structure and/or a fabric, which
provides a point of attachment for the graft material and/or frame
material. In some embodiments, the porous structure is useful for
drug delivery, as discussed below. In some embodiments, the at
least a portion of one of the adjustable rings 104 and 106
comprises one or more biologically active compounds and/or active
chemical entities known in the art, for example, a drug,
therapeutic agent, anti-coagulant, anti-proliferant,
anti-inflammatory agent, and/or tissue growth modulating agent. In
some embodiments, at least a portion of one of the adjustable rings
104 and 106 is covered and/or coated with a
biodegradable/biocompatible material known in the art, for example,
polylactic acid (PLA). In some embodiments, this coating
facilitates removal.
[0120] In the illustrated embodiment, the graft member 112 is
secured to adjustable rings 104 and 106 as discussed above. In some
embodiments, the graft member 112 also secured to the frame 114 by
means known in the art, for example, using sutures, adhesives,
mechanically, thermal welding and/or bonding, or combinations
thereof. These methods are described in greater detail above. In
some embodiments, the graft member 112 is secured to the frame 114
at or near the end of the proximal end 126 or the distal end 124 of
the implant 100. In some embodiments, the graft member 112 is
secured to the frame 114 at another location. In some embodiments,
securing the graft member 112 to the frame 114 provides one or more
advantages, for example, improved durability or strength, and/or
increased lumen size, which provides improved blood flow.
[0121] The prosthetic valve implant 100 is sized to facilitate
implantation, such as percutaneous implantation through the femoral
artery. In some embodiments, the graft implant 100 is loaded in an
introduction or deployment catheter in a collapsed configuration
(not illustrated), the catheter inserted into the femoral artery
percutaneously, the catheter advanced to the left ventricle, the
prosthetic valve implant 100 deployed from the catheter, the
prosthetic valve implant 100 implanted, for example, using a
balloon, and the introduction catheter and balloon removed. In some
embodiments, the diameters of one or more of the adjustable rings
104 and/or 106 are adjusted during implantation, for example, using
a balloon and/or other means known in the art.
[0122] In some embodiments, the valve implant 100 is adjusted in
vivo by applying an energy source, for example, radio frequency
energy, X-ray energy, microwave energy, ultrasonic energy such as
high intensity focused ultrasound (HIFU) energy, light energy,
electric field energy, magnetic field energy, combinations of the
foregoing, or the like. Application of energy sources is discussed
in greater detail above. In some embodiments, the energy source is
applied in a non-invasive manner from outside the body. For
example, as discussed above, an MRI device is useful for applying
an amount of a magnetic field and/or RF pulse energy sufficient to
adjust the valve implant 100. In some embodiments, the energy
source is applied internally, for example, by surgically inserting
a catheter into the body and applying energy through the
catheter.
[0123] In some embodiments, the adjustment is performed in a single
step. In certain embodiments, the adjustment is performed in a
plurality of steps. In some embodiments, the adjustment steps are
remote in time, which is useful, for example, where the aortic
valve enlarges after initial implantation of the valve implant 100.
Those skilled in the art will understand that in some embodiments,
different regions of the valve implant 100 are adjusted to
different extents, or not adjusted at all. For example, in some
embodiments, each of the adjustable rings 104 and 106 is
independently adjusted.
[0124] FIG. 1B illustrates the adjustable prosthetic valve implant
100 of FIG. 1A in an adjusted state according to certain
embodiments. In the illustrated embodiment, each of the adjustable
rings 104 and 106 has been adjusted to a larger diameter.
Furthermore, the central region of the implant has maintained its
original diameter. In certain embodiments, the central region may
maintain its diameter due to the substantially rigid structure of
the frame 114. In some embodiments, the central region may comprise
an adjustable ring that maintains its original diameter while the
other adjustable rings 104 and 106 expand in diameter.
[0125] The adjustment process, either non-invasive or using a
catheter, is performed either all at once or incrementally in steps
to achieve the desired amount of adjustment for producing the
desired clinical result. If heating energy is applied such that the
temperature of the adjustable element does not reach the A.sub.f
temperature for a substantially maximum shape change, partial shape
memory transformation occurs. FIG. 1C graphically illustrates the
relationship between the temperature of an embodiment of a
contractible adjustable element and its diameter or transverse
dimension according to certain embodiments. At body temperature of
approximately 37 degrees Celsius, the diameter of the adjustable
element has a first diameter d.sub.o. The shape memory material is
then increased to a first temperature T.sub.o. In response, the
diameter of the adjustable element reduces to a second diameter
d.sub.n. The diameter of the adjustable element is then further
reduced to a third diameter d.sub.nm by raising the temperature to
a second temperature T.sub.2.
[0126] As graphically illustrated in FIG. 1C, in some embodiments,
the change in diameter from d.sub.0 to d.sub.nm is substantially
continuous as the temperature is increased from body temperature to
T.sub.2. For example, in some embodiments, a magnetic field of
about 2.5 Tesla to about 3.0 Tesla is used to raise the temperature
of the adjustable element above the A.sub.f temperature to complete
the austenite phase transition and to return the adjustable element
to the remembered configuration. In some embodiments, a magnetic
field of about 2.0 Tesla to about 4.0 Tesla is used. In some
embodiments, however, a lower magnetic field (e.g., 0.5 Tesla) is
initially applied and increased (e.g., in 0.5 Tesla increments)
until the desired level of heating and desired contraction of the
adjustable element is achieved. In some embodiments, the adjustable
element comprises a plurality of shape memory materials with
different activation temperatures and the diameter of the
adjustable element is reduced in steps as the temperature
increases.
[0127] Whether the shape change is continuous or stepwise, the
diameter or transverse dimension, or another dimension of the
adjustable element is assessed and/or monitored in some embodiments
during the adjustment process by MRI imaging, ultrasound imaging,
computed tomography (CT), X-ray, or the like. In some embodiments,
where magnetic energy is being used to activate an adjustable
element, for example, MRI imaging is performed at a field strength
that is lower than that required for activation of the adjustable
element.
[0128] In some embodiments, one or more components and/or regions
thereof of the valve implant 100 comprises a low friction coating,
which facilitates insertion and placement of the device. For
example, in some embodiments, a low friction coating is applied to
at least a portion of each of the adjustable rings 104 and 106, the
frame 114, or combinations thereof. The low friction coating
comprises any suitable low friction coating known in the art, for
example, fluorinated polymers, including EPTFE, PTFE (Teflon.RTM.),
and the like. Other low friction coatings comprise lubricants known
in the art, oils, and in particular non-toxic oils. In some
embodiments, the low friction coating assists in removal of the
device 100, if needed.
[0129] In certain embodiments, the prosthetic valve implant 100,
upon activation, may change from a substantially linear (or
"straight") shape to a substantially helical or substantially
spiral shape. In certain embodiments, the change may occur to
certain segments of the implant 100. In certain embodiments, the
shape change may occur along the entire length of the implant
100.
[0130] FIG. 1D depicts a prosthetic valve implant 100 of FIG. 1A
deployed in a natural aortic valve position. In certain
embodiments, the valve 100 may be implanted at a desired target
location 132 in a body duct, for example, the aorta 140.
[0131] In certain embodiments, the valve implant 100 may delivered
to a target location percutaneously in an antegrade (relative to
the direction of blood flow) approach using a guide wire to gain
access through the superior or inferior vena cava, for example,
through groin access for delivery through the inferior vena cava. A
guiding sheath can be advanced over the guide wire and into the
inferior vena cava. The distal end of the guiding sheath can be
passed through the right atrium and towards the septum. Once the
distal end of the guiding sheath is positioned proximate to the
septum, a needle or piercing member is preferably advanced through
the guiding sheath and used to puncture the fossa ovalis or other
portion of the septum. In some embodiments, the guiding sheath is
dimensioned and sized to pass through the fossa ovalis without
requiring a puncturing device. That is, the guiding sheath can pass
through the natural anatomical structure of the fossa ovalis into
the left atrium, and then into the left ventricle 146, where access
to the aortic valve 132 may be achieved. In certain embodiments,
the valve implant 100 may be delivered to a target location
percutaneously using an retrograde (relative to the direction of
blood flow) approach, where the aortic valve is approached from the
descending aorta.
[0132] In certain embodiments, the valve 100 may be advanced while
mounted over a balloon delivery device until it reaches the desired
target location in a body duct 132. The balloon may then be
inflated and the implant 100 may expand radially to take up its
position, as illustrated. The prosthetic valve implant 100, which
in certain embodiments comprises an artificial valve replacement in
the central section of the implant 100, may thus replace the aortic
valve 132 when implanted.
[0133] In certain embodiments, the adjustable prosthetic valve
implant 100 of FIG. 1A may be adjusted after implantation. For
example, as shown in phantom, the adjustable elements 106 and 104
at the proximal and distal ends of the implant may be adjusted to a
larger diameter so as to abut the inner walls of the aorta 140 and
left ventricle 146 respectively, in order to prevent or reduce
post-surgical paravalvular leakage. In certain embodiments, the
diameter of the central section of the implant 100 during
implantation is configured to be substantially the same as the
diameter of the aortic valve 132 after delivery to the target
location 132. Furthermore, in certain embodiments, the central
region of the implant may comprise an adjustable element which may
be similarly adjusted in order to address post-surgical
complications. In certain embodiments containing an adjustable
element in the central section of the implant 100, the adjustable
element of the central section may be adjusted post-operatively
during a first procedure while the adjustable elements in the
proximal and distal ends of the implant may be adjusted during a
second post-operative procedure.
[0134] FIG. 2A illustrates another embodiment of the prosthetic
valve implant 200 that is similar to the embodiment illustrated in
FIG. 1A. The prosthetic valve implant 200 comprises an additional
adjustable ring substantially equidistant from the adjustable rings
204 and 206 located at the distal and proximal ends of the implant,
respectively. The construction and materials for this embodiment
are substantially similar as described above for the embodiment
illustrated in FIG. 1A.
[0135] In the illustrated embodiment, the body 210 comprises one or
more adjustable elements, which permit the shape of the body 210 to
be adjusted post implantation. In the illustrated embodiment, the
adjustable elements 202, 204, and 206 are disposed at the center
and the ends of the implant 200. Those skilled in the art will
understand that other configurations are possible. The adjustable
elements are, for example, shaped memory materials in the form of
rings, wires, bands, strips, and the like. In the illustrated
embodiment, the adjustable elements 202, 204, and 206 are
integrated with the frame 214. In certain embodiments, the
adjustable elements 202, 204, and 206 are separate from the frame
214.
[0136] FIG. 2B illustrates the prosthetic valve implant 200 of FIG.
2A after activation. In the illustrated embodiment, expanding the
adjustable elements 202, 204, and 206 causes the shape of the
prosthetic valve implant 200 to change. Adjustable rings 204 and
206 have been expanded, while adjustable ring 202 has contracted.
Consequently, the central region of the implant 200 has contracted
radially and the end regions have expanded radially. In some
embodiments, the maximum diameter of the expanded portion is from
about 5 cm to about 8 cm. In some embodiments, the minimum diameter
of the contracted portion is from 0.25 to 0.5 cm.
[0137] FIG. 3A illustrates another embodiment of the prosthetic
valve implant 300 that is similar to the embodiment illustrated in
FIG. 2A. The prosthetic valve implant 300 comprises expanding
adjustable elements 302, 304, and 306. Adjustable rings 304 and 306
are located at the ends of the implant 300, while adjustable ring
306 is located in the central region of the implant 300. The
construction and materials for this embodiment are substantially
similar as described above for the embodiment illustrated in FIG.
1A.
[0138] FIG. 3B illustrates the prosthetic valve implant 300 of FIG.
3A after activation of the adjustable ring 302 located in the
central region of the implant 300. The adjustable ring 302 has
expanded radially. The other two adjustable rings, 304 and 306,
have not been activated, and therefore maintain their original
shape. Expanding the adjustable ring 302 causes the central region
of the adjustable implant 300 to also expand. The end regions,
however, have maintained their original shape, as discussed
above.
[0139] However, when adjustable rings 304 and 306, which are
located at the ends of the implant 300, are activated, the rings
304 and 306 expand radially, causing the end regions of the implant
300 to also expand radially, as illustrated in FIG. 3C. Certain
areas of the implant 300 nonetheless maintain substantially the
same original diameter, such as the two bands 310 and 308 located
substantially equidistant between each either end ring 304 and 306
and the central ring 302. However, in some embodiments, expanding
all rings in an implant may cause the entire implant to expand
without any portion maintaining its original radius.
[0140] FIG. 4A illustrates another embodiment of the prosthetic
valve implant 400 that is similar to the embodiment illustrated in
FIG. 2A. The prosthetic valve implant 400 comprises expanding
adjustable elements 402, 404, and 406. Adjustable rings 404 and 406
are located at the ends of the implant 400, while adjustable ring
406 is located in the central region of the implant 400. The
construction and materials for this embodiment are substantially
similar as described above for the embodiment illustrated in FIG.
1A.
[0141] FIG. 4B illustrates the prosthetic valve implant 400 of FIG.
4A after activation of adjustable rings 402, 404, and 406 located
in the central and end regions of the implant 400. Each of the
adjustable rings 402, 404, and 406 has expanded radially, causing
the entire implant to expand radially without any portion
maintaining its original radius.
[0142] FIG. 5A illustrates another embodiment of the prosthetic
valve implant 500 that is similar to the embodiment illustrated in
FIG. 2A, except that when activated, the adjustable portions of the
implant 500 expand in the axial, or longitudinal, direction,
instead of radially. The prosthetic valve implant 500 comprises
expanding adjustable elements 502, 504, and 506. Adjustable rings
504 and 506 are located at the ends of the implant 500, while
adjustable ring 506 is located in the central region of the implant
500. The implant 500 further comprises an adjustable frame 514
element, which may adjust the length of the implant 500 to a longer
length. The construction and materials for this embodiment are
substantially similar as described above for the embodiment
illustrated in FIG. 1A.
[0143] FIG. 5B illustrates the prosthetic valve implant 500 of FIG.
5A after activation. In some embodiments, activation of the
adjustable material provides a decrease in length. In some
embodiments, activation of the adjustable material provides an
increase in length, as illustrated. The frame element 514 has been
adjusted to a greater longitudinal length. In certain embodiments,
length change may be effected using any shape memory material
described above, such as nitinol. In some embodiments, the change
in length is from about 5% to about 25%. In some embodiments, the
diameter of the adjustable portion also changes, for example,
increases, on adjustment, either by adjusting the frame 514 or the
adjustable rings 502, 504, and 506.
[0144] FIG. 6 illustrates a lateral view, looking along the flow
path, of another embodiment of a prosthetic valve implant 600
having a "D" shape that is adjustable after implantation. The
implant 600 is illustrated in an unadjusted configuration in solid
lines, and in an adjusted configuration in phantom. The implant 600
comprises a substantially flat edge 604 and a substantially arcuate
edge 602. In certain embodiments, the flat edge 604 can be
continuous. In certain embodiments, the flat edge 604 may comprise
a break or discontinuity.
[0145] In certain embodiments, the implant 600 may be fabricated
from shape-memory materials, as described above. For example, in
certain embodiments, the frame may comprise shape memory materials,
such as nitinol. In certain embodiments, the implant 600 may be
configured to have a post-actuation shape when the temperature is
raised above the A.sub.f temperature. In certain embodiments, the
implant 600 may be comprised of multiple elements, at least one of
which comprises a shape memory material. Each shape memory element
may be configured to have different activation temperatures and
austenitic shapes. In certain embodiments, the implant 600 is
fabricated from wire, tubing, flat wire, "U" channel or the like.
In certain embodiments, the implant 600 may further comprise
elements such as a tube with an internal wire, multiple laminated
flat wires, or the like.
[0146] Upon adjustment of the prosthetic valve implant 600, the
substantially straight section 604 extends in length while the
height of the substantially arcuate section 602 decreases. In
certain embodiments, which have no break in continuity on the flat
side 604, as illustrated, the circumference of the implant 600 may
remain substantially unchanged. In certain embodiments where there
is a break in continuity on the flat side 604, the circumference of
the implant may change.
[0147] FIG. 7 illustrates a lateral view, looking along the flow
path, of another embodiment of a prosthetic valve implant 700
having a "D" shape that is adjustable after implantation. The
implant 700 is illustrated in an unadjusted configuration in solid
lines, and in an adjusted configuration in phantom. The
construction and materials for this embodiment are substantially
similar as described above for the embodiment illustrated in FIG.
6.
[0148] Upon adjustment of the prosthetic valve implant 700, the
substantially straight section 704 decreases in length while the
height of the substantially arcuate section 702 increases. In
certain embodiments which have no break in continuity on the flat
side 704, as described above and as illustrated in FIG. 7, the
circumference of the implant 700 may remain substantially
unchanged.
[0149] FIG. 8 illustrates a side view of an embodiment of a
prosthetic valve implant 800 according to certain embodiments. The
implant 800 is illustrated in an unadjusted configuration in solid
lines, and in an adjusted configuration in phantom. The central
region 802 of the implant 800 comprises an inward depression 808 on
one side. The construction and materials for this embodiment are
substantially similar as described above for the embodiment
illustrated in FIG. 6. Upon adjustment of the prosthetic valve
implant 800, the central region 802 comprises a plurality of inward
depressions 808. In certain embodiments, the inward depressions 810
may be bilateral. In certain embodiments, the inward depressions
810 may be asymmetric. In certain embodiments, the inward
depressions 810 which result from the adjustment may result in a
circumferential groove or depression. In certain embodiments, the
upstream end 806 portion and the downstream end 804 portion remain
unaffected by the adjustment.
[0150] FIG. 9 illustrates a side view of an embodiment of a
prosthetic valve implant 900 according to certain embodiments. The
implant 900 is illustrated in an unadjusted configuration in solid
lines, and in an adjusted configuration in phantom. The central
region 902 of the implant 900 comprises an inward depression 908 on
one side, similar to the embodiment 800 illustrated in FIG. 8. The
construction and materials for this embodiment are substantially
similar as described above for the embodiment illustrated in FIG.
6. Upon adjustment of the prosthetic valve implant 900, the
depression 908 increases in depth and width. The depression 908 in
the side of the implant 900 in its adjusted shape has become
substantially larger than in the unadjusted configuration. In
certain embodiments, the upstream end 906 portion and the
downstream end 904 portion remain unaffected by the adjustment.
[0151] Although the embodiments of the adjustable prosthetic valve
implant described so far are substantially linear, in certain
embodiments the implant may take any other shape. For example, FIG.
10A illustrates a first side view of an unadjusted implant 1000
having a "C"-shaped configuration and comprising a first end 1004,
a central region 1006, and a second end 1002. The implant 800 is
illustrated in an unadjusted configuration in solid lines, and in
an adjusted configuration in phantom. In the illustration, the
second end 1002 of the implant 1000 is deflected out of the plane
of the "C." FIG. 10B illustrates a second side view of the C-shaped
implant 1000 of FIG. 10A. From this view, the implant 1000 has a
C-shape appearance.
[0152] Upon activation, the first end 1004 of the prosthetic valve
implant 1000 is deflected out of the place of the "C."
Consequently, after activation, both the first end 1004 and the
second end 1002 of the "C" are deflected in opposite directions out
of the plane of the "C". The curved region 1006 remains
substantially within the original unadjusted plane, thus retaining
the C-shape of the implant 1000.
[0153] FIG. 11A illustrates a side view of an unadjusted prosthetic
valve implant 1100 comprising a three-post crown support 1104 near
a central valve, a base ring structure 1102 and a plurality of
attachment posts 1106. The construction and materials for this
embodiment are substantially similar as described above for the
embodiment illustrated in FIG. 1. The illustrated implant 1100 is
suitable for structurally housing a prosthetic valve, such as a
trileaflet tissue valve. The crown support 1114 may allow for safe
attachment of the implant 1100 to a valve by means of stitching or
other suitable attachment method. In certain embodiments, the crown
support 1114 may be connected to at least one end of the adjustable
prosthetic valve implant in order to beneficially increase holding
capabilities within the cardiovascular system when adjusted.
[0154] FIG. 11B illustrates a side view of the adjusted implant
1100 of FIG. 11A when activated. Upon activation, the attachment
points 1106 and crown structures 1104 deflect radially outward. In
certain embodiments, deflection may also occur in the radially
inward direction.
[0155] FIG. 11C illustrates a side view of the implant 1100 of FIG.
11A attached to the central section of the adjustable prosthetic
valve implant 100 of FIG. 1A and deployed in a natural aortic valve
position. The addition of the crown implant 1100 to the prosthetic
valve implant may increase the holding capacity of the prosthetic
valve implant in the aortic valve 132 when adjusted, as shown in
phantom.
[0156] FIG. 12A illustrates an embodiment of an adjustable element
1200 comprising a U-shaped shape memory element 1210 on which is
disposed a coating or layer 1220. As discussed above, suitable
coatings include thermally insulators, electrical insulators,
energy absorbing materials, porous materials, lubricating
materials, bioactive materials, biodegradable materials,
combinations thereof, and the like. In the illustrated embodiment,
the layer and/or jacket 1220 is a thermal insulation layer, for
example, a polymer layer. A portion of the insulating layer 1230
remains exposed in the illustrated embodiment. In some embodiments,
the insulating layer 1230 also serves another function, for
example, as a HIFU absorbing material, a MRI absorbing material, a
lubricating layer, a drug eluting layer, a biodegradable layer, a
porous layer, and combinations thereof.
[0157] FIG. 12B illustrates another embodiment in which the shape
memory element 1210 is a ring. A plurality of windows 1230 are
provided in the insulation layer 1220. In these embodiments, the
insulation layer reduces heat loss, thereby facilitating activation
of the shape memory element. FIG. 12C illustrates a side, partial
breakaway view of an unadjusted implant 1250 comprising an energy
absorbing coating 1220 on its exterior surface.
[0158] In the embodiment illustrated in FIG. 13A, an adjustable
element 1300 comprises a ring-shaped shape memory element 1310 and
a fine wire 1320 wrapped thereon. The fine wire 1320 is any
suitable conductive wire, for example, platinum coated copper,
titanium, tantalum, stainless steel, gold, and combinations
thereof. As discussed above, in some embodiments, the wire 1320
forms a loop suitable for inductive heating. The fine wire 1320
permits focused and/or rapid heating of the adjustable element 1300
using, for example, by induction, while reducing heating of
surrounding tissue. The fine wire 1320 is from about 0.05 mm to
about 0.5 mm in diameter. Those skilled in the art will understand
that different wrapping geometries are also useful, for example,
circumferential and/or wrapping on a bias. Some embodiments
comprise additional wrapped wire, for example, in additional
layers, or disposed at selected potions of the adjustable element.
As discussed above, some embodiments comprise a thermally
insulating, electrically insulating, protective, and/or covering
layer.
[0159] FIG. 13B illustrates a side, partial breakaway view of an
unadjusted implant comprising a fine wire 1320 on the exterior
surface of its outer wall 1328. The wire 1320 may be wrapped around
the expandable and contractible shape memory wall comprising the
implant 1350 in a fashion similar to that used to wrap the
adjustable element in FIG. 13A. In certain embodiments, the wire
1320 may further be combined and layered under, or over, the energy
absorbing coating 1220, detailed in FIGS. 12A-12C. In certain
embodiments, an insulating layer 1322 can be disposed exterior to
the heating coil 1320 to minimize heat transfer to surrounding
tissue.
[0160] In some embodiments, the adjustable elements in the graft
implant are activated using one or more purpose built devices which
are positioned on or around a patient's body in such a way to focus
the energy on the adjustable elements. In some embodiments, the
purpose built device is wrapped around the patient.
[0161] FIG. 14A illustrates an embodiment of an adjustable ring
and/or adjustable element 1424, which is expandable and/or
contractible upon activation. The adjustable ring 1424 does not
form a closed shape. That is, the adjustable ring 1424 comprises a
first end 1425 and a second end 1426 that do not contact, thereby
forming a C-shaped and/or G-shaped structure. In the illustrated
embodiment, the adjustable ring 1424 is substantially flat. In
certain embodiments, the adjustable ring 1424 is not flat. FIG. 14B
illustrates the adjustable ring 1424 of FIG. 14A after activation.
In the illustrated embodiment, the adjustable ring 1424 contracts
on activation. The dimension B in FIG. 14B is less than the
corresponding dimension A FIG. 14A, and the dimension b in FIG. 14B
is less than the corresponding dimension a in FIG. 14A. Those
skilled in the art will understand that in certain embodiments, the
adjustable ring 1424 expands on activation.
[0162] FIG. 15 illustrates an embodiment of a prosthetic implant
1500 that is similar to the embodiment illustrated in FIG. 1A, in
which the adjustable ring 1506 is similar to the adjustable ring
illustrated in FIG. 14A.
[0163] Another embodiment of an adjustable ring and/or adjustable
element 1000 is illustrated in FIG. 16A comprising a ring member
1610 and a ratchet member 1620. In the illustrated embodiment, the
ends of the ring member 1612 and 1614 are disposed within the
ratchet member 1620. The ratchet prevents undesired size changes in
the adjustable element, caused, for example, by pulsatile dilation
and contraction of the aorta, common iliac arteries, and/or AAA.
Suitable ratchet mechanisms are known in the art. An embodiment of
the ratchet member 1620 is illustrated in cross-section in FIG.
16B. The ratchet member 1620 comprises internal gripping elements
1622 which permit one-way motion of the ends of the ring member
1612 and 1614 therein. The ring member 1610 comprises a shaped
memory material, for example, nitinol. The adjustable ring 1600 is
expandable and/or contractible on activation. For example, the
dimensions A and a in the activated configuration (FIG. 16B) are
larger than the dimensions B and b in the unactivated configuration
(FIG. 16A) in some embodiments and are smaller in some embodiments.
In certain embodiments, one of the dimensions is larger
post-activation, and the other is smaller. In certain embodiments,
one of the dimensions substantially does not change on activation.
In some embodiments, the entire ring member 1610 is a shape memory
material, for example, nitinol, while in certain embodiments, the
ring member 1610 comprises a material other than a shaped memory
material. For example, in some embodiments, the ring member 1610 is
a composite.
[0164] FIG. 17A illustrates another embodiment of an adjustable
ring and/or adjustable element 1700 comprising a groove 1710
disposed along the outer periphery of the ring 1700. The adjustable
element 1700 comprises a first end 1720, which in the illustrated
embodiment, is an inner end, and a second end 1730, which in the
illustrated embodiment is an outer end. In the illustrated
embodiment, adjustable ring 1700 contracts upon activation as
illustrated in FIG. 17B and FIG. 17C. As illustrated in the
sequence of FIGS. 17A-17C, the groove 1710 guides the first and
second ends 1720 and 1730, thereby maintaining a substantially
planar configuration. In some embodiments, the adjustable ring 1700
expands on activation, for example, in the sequence of FIGS.
17C-17A. Those skilled in the art will understand that in some
embodiments, the groove 1710 is disposed on the inner surface of
the adjustable ring 1700. FIG. 17C also illustrates holes 1740,
which are useful, for example, for securing the adjustable ring
1700 to the graft implant.
[0165] FIG. 18A illustrates in cross-section another embodiment of
an adjustable element 1800 comprising a body member 1810, which
comprises a recess 1820. In the illustrated embodiment, the body
member 1810 is generally concave, defining a space 1812. In the
illustrated embodiment, the recess 1820 is formed on the concave
portion of the body member 1810. A movable member 1830 is disposed
in the recess 1820. Between the body member 1810 and the movable
member 1830 is disposed a shape memory element 1840. In some
embodiments, the body member 1810 is substantially rigid, for
example, a metal, a polymer resin, which is reinforced in some
embodiments, or a composite. In some embodiments, the movable
member 1830 is flexible, elastic, and/or elastomeric, for example,
polymers, silicone rubber, synthetic rubber, fabrics, other
elastomeric materials known in the art, and combinations and/or
composites thereof. In some embodiments, the movable member 1830 is
substantially rigid. The shape memory element 1840 comprises one or
more suitable shape memory materials disclosed herein, for example,
nitinol.
[0166] FIG. 18B illustrates the adjustable element 1800 after
activation. In this case the shape memory element 1840 expands,
thereby urging the movable member 1830 into the space 1812, thereby
reducing the volume of the space 1812. Those skilled in the art
will understand that, in certain embodiments, the adjustable
element is configured such that a movable member is disposed on a
convex portion of a body member, thereby increasing the diameter of
an adjustable element, while in certain embodiments, the adjustable
element is configured such that a movable member is disposed on a
substantially planar portion of the body member, thereby increasing
the length and/or width of the adjustable element.
[0167] FIGS. 19A and 19B illustrate cross sections of embodiments
of adjustable elements 1900 comprising a convoluted shape memory
element 1910 and a coating and/or layer 1920 Suitable coatings
and/or layer materials are discussed above. In FIG. 19A, the
convoluted shape memory element is in the shape of a coil, while in
FIG. 19B, it is pleated. The unadjusted sizes of the adjustable
elements 1900 are shown in phantom.
[0168] FIG. 20A illustrates in partial cross section an embodiment
of a generally circular adjustable element 2000 in an unadjusted
configuration comprising a first end 2010 and a second end 2020.
The first end comprises a recess 2012 into which a reduced diameter
portion 2022 of the second end is slidably inserted. FIG. 20B
illustrates the adjustable element 2000 of FIG. 20A after
adjustment, in which the reduced diameter portion 2022 is partially
withdrawn from the recess 2022, and the diameter D of the
adjustable element increased.
[0169] FIG. 21A illustrates an embodiment of an activation post
2100 capable of being attached to embodiments of the adjustable
prosthetic valve implant as disclosed herein. The activation post
2100, or energy transfer member, is configured to project out into
the bloodstream for docking with an catheter configured to adjust
an implant.
[0170] The activation post 2100 comprises a rod 2102, a sphere
2108, a positive conductive electrode 2104, a negative conductive
electrode 2106, and an electrical insulation element 2110. The
sphere 2108 is affixed to the end of the rod 2102. In certain
embodiments, the electrodes 2104 and 2106 may be operably connected
to activation elements in the implant. In certain embodiments, the
activation elements can be fabricated from high resistance metals
or ceramics such as nickel chromium wire.
[0171] FIG. 21B illustrates a distal end of one embodiment of an
adjustment catheter 2120 for adjusting embodiments of the
adjustable prosthetic valve implant as disclosed herein. The
illustrated adjustment catheter 2120 comprises a plurality of
keyway slots 2124 and 2126 disposed on opposite sides of the
catheter 2120. In certain embodiments, the keyway slots may be
located in different positions in relation to one another. Each
keyway slot 2124 and 2126 further comprises a plurality of distal
lead-in gradual tapers 2130 and 2128. In some embodiments, the
inside diameter edges 2136 of the slots 2124 and 2126 or the tapers
2130 and 2128 are sharpened to cut through tissue which can build
up around the adjustment post 2100 of FIG. 21A. In certain
embodiments, the edges 2136 may also comprise a roughened surface
structure in order to abrade away tissue that might interfere with
electrical transmission. In certain embodiments, the catheter 2120
further comprises electrodes 2132 and 2134 which are electrically
isolated from each other and insulated except at the edges of the
slots 2124 and 2126. The electrodes 2132 and 2134 may be operably
connected to electrical lines that run the length of the catheter
2120 to the proximal end where they are operably connected to
plugs, sockets, or appropriate energy sources. In certain
embodiments, an electrode may be connected to an energy source via
a lead configured to conduct any form of electromagnetic or
mechanical energy, such as a fiber optic wire or electrical
wire.
[0172] In certain embodiments, when the activation post 2100 comes
into contact with an electrode 2132 or 2134, activation energy may
be transferred from the catheter 2120 to the
[0173] The adjustment catheter 2100 may be used to activate an
adjustable prosthetic implant as disclosed herein by first
connecting an adjustment post 2100 to an interior surface of an
implant 2112. In certain embodiments, the opposite end of the
adjustment post 2100 may project into the bloodstream. In certain
embodiments, the opposite end of the adjustment post 2100 may
reside in the same cylindrical region as the implant 2112, where it
may contact tissue. In certain embodiments, electrical insulation
may be provided to prevent activation energy, such as adjustment
currents and voltages, from causing tissue burn. In certain
embodiments, guidance of the catheter 2120 to the adjustment post
2120 may be facilitated using external means, such as fluoroscopic
guidance or ultrasound imaging. The adjustment post 2100 may be
docked with the adjustment catheter 2120 by passing the ball 2108
into the central lumen of the adjustment catheter 2120, then
through the tapered opening, 2128 or 2130, and into one of the
slots 2124 or 2126. In certain embodiments, the slots 2124 and 2126
may advantageously lock or otherwise securely hold the activation
post 2100. Either electrode 2132 or 2134 may thus transfer
electrical energy to the implant 2112 through the post 2100. In
certain embodiments, alignment of the electrodes 2132 and 2134 with
the electrodes 2104 and 2106 facilitates proper electrical energy
delivery.
[0174] FIG. 22 illustrates a distal end of another embodiment of an
adjustment catheter 2200 for adjusting embodiments of the
adjustable prosthetic valve implant as disclosed herein. The
adjustment catheter 2200 comprises an insulating catheter body
2202. The catheter body 2202 comprises a central lumen 2214, a
positive electrode 2206 and a negative electrode 2212. In certain
embodiments, the negative electrode 2212 is also the outer surface
of an inwardly angled tab 2220, which is bent inward and spring
loaded to engage the adjustment post 2100 discussed in FIG. 21A. In
certain embodiments, the adjustment catheter 2200 may also comprise
a cutout 2218. In certain embodiments, the slot edges 2216 can
comprise sandpaper-like edges or other roughened surfaces to remove
tissue buildup on the post 2100, as described above. In certain
embodiments, a plurality of separate and electrically isolated
conductors may operably connect the electrodes 2206 and 2212 to the
proximal end of the catheter 2200, as described above.
[0175] FIG. 23A illustrates an adjustment post 2300 connected to a
prosthetic valve implant 2312 according to certain embodiments. The
adjustment post 2300 comprises a quick release pin 2302, a
spring-loaded positive electrode 2304 and a spring-loaded negative
electrode 2306. In certain embodiments, the adjustment post 2300
further comprises a central lumen 2318 which may be open or closed
at its end. The electrodes 2304 and 2306 may be affixed to spring
loaded arms 2310 and 2308 respectively. In certain embodiments, the
electrodes 2304 and 2306 may project out through ports 2314 and
2316, respectively, in the post 2302. In certain embodiments, the
electrodes 2304 and 2306 may project out in other ways. In certain
embodiments, the electrodes 2304 and 2306 may be operably connected
to activation elements surrounding the implant 2312. In certain
embodiments, the electrodes 2304 and 2306 may be operably connected
to activation elements within the implant 2312.
[0176] FIG. 23B illustrates a distal end of another embodiment of
an adjustment catheter 2330 for adjusting embodiments of the
adjustable prosthetic valve implant as disclosed herein. The
adjustment catheter 2330 comprises a catheter shaft 2332, a central
lumen 2344, and a slot 2342. In certain embodiments, the slot 2342
is longer in one direction than another. For example, in the
embodiment illustrated, the length of the slot 2342 in the
circumferential direction is longer than the length of the slot
2342 in the axial direction. The slot 2342 may provide a
communication channel between the central lumen 2344 and the
exterior of the catheter 2330. In certain embodiments, the catheter
2330 further comprises at least one positive electrical connector
2336 and at least one negative electrical connector (on the
interior wall, not shown). The electrical connectors may be used to
engage electrodes 2304 and 2306 on an implant 2312 (FIG. 23A). The
electrical connectors on the catheter 2330 may be electrically
isolated and operably connected to the proximal end of the catheter
2330, as discussed above.
[0177] An embodiment of a wrappable inductive activation device
2400 is illustrated in FIG. 24. The device 2400 comprises a
wrapping member 2410 dimensioned and configured to wrap around a
patient's abdomen. The wrapping member 2400 is at least
circumferentially flexible, and comprises a flexible material known
in the art, for example, a woven fabric, a non-woven fabric,
textile, paper, a membrane and/or film, combinations thereof and
the like. In some embodiments, the wrapping member 2410 is at least
the circumferentially elastic. In the illustrated embodiment, the
wrapping member 2410 comprises a closure 2420, which facilitates
securing and removing the device 2400 to and from a patient.
Suitable closures 2420 are known in the art, for example, laces,
hooks, snaps, buttons, buckles, belts, ties, slide fasteners
(Zippers.RTM.), hook and loop fasteners (Velcro.RTM.), combinations
thereof, and the like. The device 1500 also comprises one or more
conductive coils 2430, which are used to generate one or more
electromagnetic fields for activating the graft implant. Some
embodiments comprise circumferential coils.
[0178] The electrical current in the coil(s) 2430 is controlled
using any suitable controller (not illustrated). In some
embodiments, the current control is automated, for example, using a
computer, microprocessor, data processing unit, and the like. As
discussed above, in some embodiments, the graft implant is
dynamically remodeled, that is, the graft implant contemporaneously
imaged and adjusted. In some embodiments, the controller is
integrated with a system for imaging at least an adjustable element
in the graft implant. As discussed above, in some embodiments, an
adjustable element is adjusted in steps. Dynamic remodeling permits
a user to monitor the effectiveness of each adjustment step.
[0179] While certain aspects and embodiments of the invention have
been described, these have been presented by way of example only,
and are not intended to limit the scope of the invention. Indeed,
the novel methods and systems described herein may be embodied in a
variety of other forms without departing from the spirit thereof.
For example, an implant and adjustment system can be configured to
be used in the mitral, pulmonary, or tricuspid position, rather
than in the aortic position. The accompanying claims and their
equivalents are intended to cover such forms or modifications as
would fall within the scope and spirit of the invention.
* * * * *