U.S. patent application number 12/960035 was filed with the patent office on 2011-06-09 for method and system for cardiac valve delivery.
Invention is credited to Bjarne Bergheim.
Application Number | 20110137408 12/960035 |
Document ID | / |
Family ID | 35137481 |
Filed Date | 2011-06-09 |
United States Patent
Application |
20110137408 |
Kind Code |
A1 |
Bergheim; Bjarne |
June 9, 2011 |
Method and System For Cardiac Valve Delivery
Abstract
The invention provides methods and systems for introducing a
delivery device in the heart at or near the apex of the heart,
wherein the delivery device includes a prosthesis, advancing the
prosthesis to the target site, and disengaging the prosthesis from
the delivery device at the target site for implantation.
Specifically, the present invention provides valve replacement
systems for delivering a replacement heart valve to a target site
in or near a heart. The valve replacement system comprises a trocar
or other suitable device to penetrate the heart at or near the apex
of the heart, a delivery member that is movably disposed within the
trocar, and a replacement cardiac valve disposed on the delivery
member. The delivery member may further comprise mechanical or
inflatable expanding members to facilitate implantation of the
prosthetic valve at the target site.
Inventors: |
Bergheim; Bjarne; (Laguna
Hills, CA) |
Family ID: |
35137481 |
Appl. No.: |
12/960035 |
Filed: |
December 3, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10831770 |
Apr 23, 2004 |
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12960035 |
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Current U.S.
Class: |
623/2.11 |
Current CPC
Class: |
A61B 2017/00247
20130101; A61F 2/2427 20130101; A61B 17/068 20130101; A61B 8/445
20130101; A61B 17/3468 20130101; A61B 2017/22097 20130101; A61B
2018/00392 20130101; A61F 2230/0006 20130101; A61F 2/01 20130101;
A61B 8/12 20130101; A61F 2/2433 20130101; A61B 2017/00243 20130101;
A61B 17/04 20130101; A61F 2/2412 20130101 |
Class at
Publication: |
623/2.11 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A valve replacement system for delivering a replacement valve to
a target site in a heart, the system comprising: a delivery device
comprising an elongate member, wherein the diameter of the delivery
device is significantly greater than the diameter of a human adult
femoral artery; and a radially collapsible and expandable heart
valve prosthesis mounted to the delivery device in a collapsed
state, wherein the heart valve prosthesis comprises a support frame
and a tissue valve secured to the support frame, wherein the
delivery device is sized and shaped to deliver the heart valve
prosthesis through an apical area of a heart to a native annulus in
a heart, and wherein the heart valve prosthesis is configured to be
expanded to an expanded state when the heart valve prosthesis is
delivered to a native annulus.
2. The system of claim 1, wherein the heart valve prosthesis is a
replacement cardiac valve.
3. The system of claim 2, wherein the heart valve prosthesis is a
replacement aortic valve.
4. The system of claim 2, wherein the heart valve prosthesis is a
replacement mitral valve.
5. The system of claim 1, wherein the delivery device is configured
to be introduced into the left ventricle of the heart.
6. The system of claim 1, wherein the delivery device is configured
to be introduced into the right ventricle of the heart.
7. The system of claim 1, wherein the support frame is constructed
from a self-expanding material.
8. The system of claim 7, wherein the support frame comprises
nitinol.
9. The system of claim 1, wherein the delivery device includes a
balloon, wherein the heart valve prosthesis is mounted on the
balloon for delivery to a native annulus, and wherein the delivery
device is configured to expand the heart valve prosthesis in a
native annulus by inflating the balloon.
10. The system of claim 1 further comprising a trocar, wherein the
trocar includes a tissue-piercing head configured to pierce a heart
at an apical area of the heart.
11. The system of claim 10, wherein the trocar includes a lumen
extending therethrough, and wherein the delivery device is
configured to be inserted into the lumen and thereby through an
apical area of a heart.
12. The system of claim 1, wherein the delivery device includes a
sheath having a lumen, wherein the heart valve prosthesis is
mounted on the elongate member, and wherein the diameter of the
sheath is greater than the diameter of the heart valve prosthesis
when the heart valve prosthesis is in the collapsed state, and
wherein the delivery device is configured such that the valve
prosthesis can be positioned within the sheath lumen during
delivery of the heart valve prosthesis to a native annulus.
13. The system of claim 12, wherein the delivery device is
configured such that the heart valve prosthesis can be removed from
the sheath when the heart valve prosthesis has been delivered to a
native annulus.
14. The system of claim 1, wherein the diameter of the delivery
device is significantly larger than approximately 8 mm and less
than approximately 25 mm.
15. A valve replacement system for delivering a replacement valve
to a target site in a heart, the system comprising: a penetration
device configured to penetrate an apical area of a heart, wherein
the penetration device comprises a central lumen; a delivery device
comprising an elongate member, wherein the diameter of the delivery
device is significantly greater than the diameter of a human adult
femoral artery; and a radially collapsible and expandable heart
valve prosthesis mounted to the delivery device in a collapsed
state, wherein the heart valve prosthesis comprises a support frame
and a tissue valve secured to the support frame, and wherein the
support frame comprises a self-expanding material; wherein the
delivery device is sized and shaped to deliver the heart valve
prosthesis through an apical area of a heart to a native annulus in
a heart, and wherein the heart valve prosthesis is configured to be
expanded to an expanded state when the heart valve prosthesis is
delivered to a native annulus.
16. The system of claim 15, wherein the delivery device includes a
sheath having a lumen, wherein the heart valve prosthesis is
mounted to the elongate member, and wherein the sheath is sized and
shaped such that the heart valve prosthesis can be positioned
within the sheath lumen during delivery of the heart valve
prosthesis to a native annulus.
17. The system of claim 16, wherein the heart valve prosthesis is
configured to self-expand to the expanded state in a native annulus
when the heart valve prosthesis is removed from the sheath.
18. The system of claim 15, wherein the heart valve prosthesis is a
replacement cardiac valve.
19. The system of claim 18, wherein the heart valve prosthesis is a
replacement aortic valve.
20. The system of claim 19, wherein the heart valve prosthesis is a
replacement mitral valve.
21. The system of claim 15, wherein the delivery device is
configured to be introduced into the left ventricle of the
heart.
22. The system of claim 15, wherein the delivery device is
configured to be introduced into the right ventricle of the
heart.
23. The system of claim 15, wherein the diameter of the delivery
device is significantly larger than approximately 8 mm and less
than approximately 25 mm.
24. A valve replacement system for delivering a replacement valve
to a target site in a heart, the system comprising: a delivery
device comprising an inner member and an outer member, wherein the
outer member has a central lumen, wherein the diameter of the outer
member is significantly greater than the diameter of a human adult
femoral artery; and a radially collapsible and expandable heart
valve prosthesis mounted to the delivery device in a collapsed
state, wherein the heart valve prosthesis comprises a support frame
and a tissue valve secured to the support frame, and wherein the
support frame comprises a self-expanding material; wherein the
delivery device is sized and shaped to deliver the heart valve
prosthesis through an apical area of a heart to a native annulus in
a heart, and wherein the heart valve prosthesis is configured to be
expanded to an expanded state when the heart valve prosthesis is
delivered to a native annulus.
25. The system of claim 24, wherein the outer member is sized and
shaped such that the heart valve prosthesis can be positioned
within the central lumen during delivery of the heart valve
prosthesis to a native annulus.
26. The system of claim 24, wherein the diameter of the outer
member is significantly larger than approximately 8 mm and less
than approximately 25 mm.
27. A system for delivering a replacement heart valve prosthesis to
the aortic region of the heart comprising: a self expandable heart
valve prosthesis comprising a stent and a tissue valve associated
with the stent, the self expandable heart valve prosthesis being
capable of assuming a contracted state and an expanded state; an
elongate tubular member having a distal end portion adapted to be
introduced into the heart through its apex, a proximal portion, and
a hollow lumen; a delivery member having a portion adapted to
receive the heart valve in its contracted state; the delivery
member and heart valve prosthesis being movably disposed within the
lumen of the elongate tubular member while the heart valve
prosthesis is in the contracted state, the delivery member being
sized and shaped to extend through an apical area of the heart to
the native aortic annulus of the heart; and wherein the heart valve
prosthesis is adapted to be expanded to an expanded state when the
heart valve prosthesis is delivered to a native aortic annulus.
28. The system of claim 27, wherein the stent comprises a nitinol
material.
29. The system of claim 27, wherein the stent is a mesh.
30. The system of claim 27, wherein the elongate tubular member
further includes a trocar.
31. The system of claim 27, wherein the delivery member includes a
tip and further includes a wire for controlling tip deflection.
32. The system of claim 27, wherein the diameter of the elongate
tubular member is significantly greater than the diameter of a
human adult femoral artery.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to methods and
systems for cardiovascular surgery. More particularly, the
invention relates to methods and systems for the repair, removal,
and/or replacement of heart valves, and also for providing
temporary valves and/or distal embolic protection during
cardiovascular surgery.
BACKGROUND OF THE INVENTION
[0002] Various surgical techniques may be used to repair a diseased
or damaged heart valve, such as annuloplasty (contracting the valve
annulus), quadrangular resection (narrowing the valve leaflets),
commissurotomy (cutting the valve commissures to separate the valve
leaflets), or decalcification of valve and annulus tissue.
Alternatively, the diseased heart valve may be replaced by a
prosthetic valve. Where replacement of a heart valve is indicated,
the dysfunctional valve is typically removed and replaced with
either a mechanical or tissue valve. Tissue valves are often
preferred over mechanical valves because they typically do not
require long-term treatment with anticoagulants.
[0003] A number of different strategies have been used to repair or
replace a defective heart valve. Open-heart valve repair or
replacement surgery is a long and tedious procedure and involves a
gross thoracotomy, usually in the form of a median sternotomy. In
this procedure, a saw or other cutting instrument is used to out
the sternum longitudinally and the two opposing halves of the
anterior or ventral portion of the rib cage are spread apart. A
large opening into the thoracic cavity is thus created, through
which the surgeon may directly visualize and operate upon the heart
and other thoracic contents. The patient must be placed on
cardiopulmonary bypass for the duration of the surgery.
[0004] Open-chest valve replacement surgery has the benefit of
permitting the direct implantation of the replacement valve at its
intended site. This method, however, is highly invasive and often
results in significant trauma, risk of complications, as well as
extended hospitalization and painful recovery period for the
patient.
[0005] Minimally invasive percutaneous valve replacement procedures
have emerged as an alternative to open-chest surgery. Unlike
open-heart procedures, this procedure indirect and involves
intravascular catheterization from a femoral artery to the heart.
Because the minimally invasive approach requires only a small
incision, it allows for a faster recovery for the patient with less
pain and bodily trauma. This, in turn, reduces the medical costs
and the overall disruption to the life of the patient.
[0006] The use of a minimally invasive approach, however,
introduces new complexities to surgery. An inherent difficulty in
the minimally invasive percutaneous approach is the limited space
that is available within the vasculature. Unlike open heart
surgery, minimally invasive heart surgery offers a surgical field
that is only as large as the diameter of a blood vessel.
Consequently, the introduction of tools and prosthetic devices
becomes a great deal more complicated. The device must be
dimensioned and configured to permit it to be introduced into the
vasculature, maneuvered therethrough, and positioned at a desired
location. This may involve passage through significant convolutions
at some distance from the initial point of introduction.
[0007] Accordingly, while heart valve surgery produces beneficial
results for many patients, numerous others who might benefit from
such surgery are unable or unwilling to undergo the trauma and
risks of current techniques. Therefore, what is needed are methods
and devices for performing heart valve repair and replacement as
well as other procedures within the heart and great vessels of the
heart that provide greater ease of access to the heart valves than
the current minimally invasive techniques, while at the same time
reducing the trauma, risks, recovery time and pain that accompany
more invasive techniques.
SUMMARY OF INVENTION
[0008] The present invention provides methods and systems for
performing cardiovascular surgery, wherein access to the heart or
great vessels is provided through the apical area of the heart. The
apical area of the heart is generally the blunt rounded inferior
extremity of the heart formed by the left and right ventricles. In
normal healthy humans, it generally lies behind the fifth left
intercostal space from the mid-sternal line.
[0009] The unique anatomical structure of the apical area permits
the introduction of various surgical devices and tools into the
heart without significant disruption of the natural mechanical and
electrical heart function. Because the methods and systems of this
invention permit direct access to the heart and great vessels
through the apex, it is not limited by the size constraints which
are presented by percutaneous surgical methods. While access to the
heart through the femoral vessels in percutaneous methods are
limited to the diameter of the vessel (approximately 8 mm), access
to the heart through the apical area is significantly larger
(approximately 25 mm). Thus, apical access to the heart permits
greater flexibility with respect to the types of devices and
surgical methods that may be performed in the heart and great
vessels.
[0010] Accordingly, it is one object of this invention to provide
methods and devices for the repair, removal, and/or replacement of
heart valves by access through the apical area of the heart.
[0011] In one preferred embodiment of the present invention, a
method for delivering a prosthesis to a target site in or near a
heart is provided. The method comprises introducing a delivery
device in the heart at or near the apex of the heart, wherein the
delivery device includes a prosthesis, advancing the prosthesis to
the target site, and disengaging the prosthesis from the delivery
device at the target site for implantation.
[0012] The present invention also provides valve replacement
systems for delivering a replacement heart valve to a target site
in or near a heart. In one embodiment, the valve replacement system
comprises a trocar or other suitable device to penetrate the heart
at or near the apex of the heart, a delivery member that is movably
disposed within the trocar, and a replacement cardiac valve
disposed on the delivery member.
[0013] The valve replacement system may be used to deliver a
variety of prosthetic heart valves, including stented and stentless
tissue valves. In another embodiment of the present invention, the
delivery member may further comprise mechanical or inflatable
expanding members to facilitate implantation of the prosthetic
valve at the target site.
[0014] In another embodiment of the present invention, an imaging
system may be provided to view the operating field. The imaging
system may be used at any time or throughout the duration of the
surgery. Imaging systems are well-known to one of skill in the art
and include transesophageal echo, transthoracic echo, intravascular
ultrasound imaging (IVUS), or an injectable dye that is radiopaque.
Cinefluoroscopy may also be utilized.
[0015] In one embodiment, the imaging system is deliverable through
a catheter or cannula to the operating field. In another embodiment
of the present invention, an ultrasound transducer may be located
on the delivery member at one or both sides of the expandable
balloon. In yet another embodiment of the present invention, the
ultrasound transducer may be located on the balloon of the delivery
member.
[0016] In yet another embodiment of the present invention, the
method and system may further comprise means to remove at least a
portion of the patient's heart valve by a cutting tool that is
disposed on the delivery member. The cutting tool may be made of an
electrically conductive metal that provides radiofrequency energy
to the cutting tool for enhanced valve removal. The high frequency
energy ablation is well known in the art.
[0017] In a further embodiment of the present invention, the
methods and devices of the present invention may be adapted to
provide a valve decalcification system, wherein the delivery member
is capable of providing the dissolution solution to the treatment
site by access through the apical area of the heart. The delivery
member may be a catheter that is configured with means to both
introduce and remove the dissolution solution to the treatment
site. The delivery member may also provide means for isolating the
treatment site to prevent the dissolution solution from entering
into the patient's circulatory system. Such means for isolating the
treatment site may include a barrier, such as a dual balloon system
on the catheter that inflate on both sides of the treatment
site.
[0018] The present invention also provides for devices and methods
for providing distal embolic protection. More particularly, the
invention provides a filter for trapping embolic material while
concurrently providing a temporary valve in the same device. The
presence of a valve in a filter assembly prevents flush back of
embolic material and debris, while still allowing fluid flow into
the filter during surgery. The valve-filter combination may be
compressed and expanded to allow entry into small blood vessels or
other body cavities. In one embodiment of the present invention, a
valve-filter assembly is implanted in the heart or great vessel of
the heart, downstream from the surgical site.
[0019] The above aspects and other objects, features and advantages
of the present invention will become apparent to those skilled in
the art from the following description of the preferred embodiments
taken together with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a partial front view of a patient's chest showing
a replacement valve delivery device introduced into the apex of the
heart through the fifth intercostal space.
[0021] FIG. 2 depicts a trocar of the replacement valve delivery
device penetrating the apex of the heart and into the left
ventricle.
[0022] FIG. 3 shows a balloon expandable delivery member being
introduced into the left ventricle through trocar positioned at the
apex of the heart.
[0023] FIG. 4 depicts a balloon expandable member being advanced
toward the aortic valve.
[0024] FIG. 5 shows the placement of the balloon expandable member
within a stenotic aortic valve.
[0025] FIG. 6 shows the expanded balloon expandable member within a
stenotic aortic valve.
[0026] FIG. 7 shows the insertion of a replacement valve delivery
member having a prosthetic replacement valve disposed around a
balloon expandable member through the apex of the heart.
[0027] FIG. 8 is a cross-sectional view of the replacement valve
delivery member positioned within the aorta.
[0028] FIG. 9 depicts the expansion of the prosthetic replacement
valve by the balloon of the replacement valve delivery member.
[0029] FIG. 10 shows a fully-expanded and deployed prosthetic
replacement valve and a disengaged replacement valve delivery
member.
[0030] FIG. 11 is a partial cross-sectional view of the heart
showing the prosthetic replacement valve positioned at the
aorta.
[0031] FIG. 12 shows one embodiment of the delivery member for use
in a valve replacement system.
[0032] FIG. 13 shows one embodiment of a valve-filter assembly,
positioned in the aorta, downstream of the aortic valve.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] FIGS. 1 through 13 show an embodiment of the method and
systems for the repair, removal, and/or replacement of heart
valves, and also for providing distal embolic protection and a
temporary valve during cardiovascular surgery.
Valve Replacement Method and System
[0034] FIG. 1 is a partial front view of the chest (11) of a
patient (10) and shows the position of the valve replacement system
(29) in relation to other anatomical landmarks, such as the sternum
(13), xiphoid (14), ribs (15), and heart (12). The valve
replacement system (29) is depicted as entering the body cavity
through the fifth intercostal space (16) and through the apex of
the heart (12). The valve replacement system (29) may enter the
body cavity through various other locations (17A, 17B and 17C) in
the chest (11).
[0035] In one preferred embodiment of the present invention, the
valve replacement system comprises a trocar or other suitable
device for penetrating the apical area of the heart and a delivery
member and a replacement prosthetic valve disposed on the delivery
member.
[0036] The methods and systems of the present invention may be used
to implant a variety of prosthetic heart valve assemblies known in
the art, including stented and stentless tissue valves. Stented
valves may be expandable by mechanical or balloon expansion
devices, or they may be self-expanding. Self-expanding stents may
be constructed from metal alloys, such as Nitinol, described in
U.S. Pat. No. 6,451,025, incorporated herein by reference.
[0037] Alternatively, the methods and devices of the present
invention may also be used to implant a stentless prosthetic heart
valve. In one embodiment of the present invention, the delivery
member is adapted to position the tissue valve at the target site
and the deliver member further comprises a means to suture or
staple the tissue valve to the valve annulus.
[0038] Examples of suitable prosthetic valves are disclosed in the
following commonly owned patents: U.S. Pat. Nos. 6,682,559;
5,480,424; 5,713,950; 5,824,063; 6,092,529; 6,270,526; 6,673,109;
6,719,787; 6,719,788; and 6,719,789, incorporated herein by
reference. Examples of other valve assemblies suitable for use in
connection with the present invention are described in U.S. Pat.
Nos. 5,411,552; 6,458,153; 6,461,382; and 6,582,462, incorporated
herein by reference.
[0039] Trocars suitable for use in connection with the present
invention typically comprise a hollow lumen and a first and second
ends. The first end comprises a means for penetrating the heart
tissue and the second end comprises a port through which the
delivery member may be introduced into the hollow lumen of the
trocar and into the heart. FIG. 2 depicts a trocar penetrating
through the apex (18) of the heart (12). The moving direction of
the trocar (31) is indicated by the arrow (19). The trocar (31) can
enter either the right ventricle (20) or the left ventricle (21).
To access the aortic or mitral valve, the trocar (31) would
preferably pass through the left ventricle (21). This yields direct
access to the aortic or mitral valve. To access the pulmonary or
tricuspid valve, the trocar (31) would preferably pass through the
right ventricle (20).
[0040] In another embodiment of the present invention, the trocar
further comprises a valve disposed within the lumen. The valve is
designed to reduce significant backflow of blood out of the heart
after the trocar is inserted into the beating heart, while at the
same time permitting the introduction of the delivery member and
other surgical devices in through the trocar. Other suitable
trocars and devices are well known in the art and are disclosed in
U.S. Pat. Nos. 5,972,030; 6,269,819; 6,461,366; 6,478,806; and
6,613,063, incorporated herein by reference.
[0041] The delivery member of the valve replacement system is
adapted to deliver the prosthetic valve to the site of
implantation, through the apical area of the heart. In one
embodiment of the present invention, the delivery member is a rod
comprising a mechanical expansion and contracting device. In one
embodiment of the present invention, the mechanical expansion and
contracting device may comprise a plurality of hollow wires in a
circular arrangement, a grip handle, and a cylinder comprising
outwardly angled holes along its perimeter. The prosthetic valve is
disposed around the mechanical expansion members in a contracted
state and delivered to the target site for implantation. Once
properly positioned, the mechanical expansion members are expanded
by pushing the wires through the angled holes and the prosthetic
valve is expanded for implantation.
[0042] In another embodiment of the present invention, the
mechanical expansion and contracting device for implanting the
prosthetic valve assembly may include a hollow tube surrounded by a
plurality of wall panels connected to a plurality of spring loaded
pins extending from the exterior of the tube to a central plate at
the interior of the tube. The central plate has spiral shaped
edges, such that rotation of the central plate pushes the pins
radially outward. Other mechanical expansion and contracting
devices are more fully described in co-pending U.S. patent
application Ser. No. 10/680,719.
[0043] In yet another embodiment of the present invention, the
delivery member may be a hollow tube having an expandable member,
such as a balloon. FIG. 3 depicts a delivery member (40) having a
balloon (41) being inserted through the apex (18) and into the left
ventricle (21) and advancing towards the native aortic valve (23)
of the heart (12). Once the balloon (41) is placed within the
aortic valve (23), it may be inflated to widen a stiff or narrowed
heart valve (stenotic heart valve) and improving blood flow through
the heart and to the rest of the body. This allows the heart to
pump more effectively and reduces pressures in the heart and lungs.
Previous methods for performing valvuloplasty required the
insertion of a catheter at the femoral artery, which is then guided
through the heart and positioned through the diseased heart valve.
The methods and devices of this present invention, however, provide
a more direct route to the valve to be treated.
[0044] FIG. 4 shows a close-up view of the delivery member (40) and
balloon (41) advancing toward the aortic valve (23) where aortic
stenosis is evident. As depicted here, the aortic valve has a
plurality of valve leaflets (24). In one embodiment, the delivery
member (40) comprises a tip or distal attachment (42) adapted to
receive a variety of auxiliary devices to assist in the valve
replacement procedure. Such auxiliary devices may include a distal
embolic protection assembly, a temporary valve, an imaging system,
a valve removal system, a valve decalcification system.
[0045] FIG. 5 shows a balloon (41) positioned in the aorta (22) and
within the aortic valve (23) and aortic valve annulus (25). The
balloon (41) is depicted as inflating in a radial direction as
indicated by the arrows (58) to compress the valvular leaflets (24)
against walls of the aorta (22). In FIG. 6, the balloon (41) is
fully inflated to widen a stenotic aortic valve (23) by pressing
the leaflets (24) against the aortic walls. An inner element (59)
may also be used for inserting a guidewire for controlling tip
deflection or a fluid infusion conduit for balloon inflation.
[0046] FIG. 7 shows the insertion of the delivery member (40)
having a balloon expansion member (41). A collapsed replacement
prosthetic valve (51) is disposed on the balloon expansion member
(41) and is introduced into the port (32) of the trocar (31). The
delivery member (40) is depicted as passing through the apex (18)
of the heart (12).
[0047] FIGS. 8-9 show expansion of the balloon (41) positioned
within the native aortic valve (23). FIG. 8 is a cross-sectional
view of the replacement valve delivery member (40) comprising a
balloon (41) and a replacement valve (51) disposed on an unexpanded
balloon (41). The replacement valve (51) is depicted here as being
positioned within the aortic valve (23). FIG. 9 depicts the radial
expansion (52) of the balloon (41) causing the replacement valve
(51) to press against the aortic valve leaflets (24) of the aortic
valve (23) against the annulus (25).
[0048] FIG. 10 shows the deployed valve in its fully expanded
state. The replacement prosthetic valve (51), as depicted here,
comprises a base ring (57) and a support structure or stent (54)
with tabs (56) to support the tissue valve (55). Once the
prosthetic valve (51) is implanted, the balloon (41) is then
deflated and the delivery member (40) is withdrawn from the body in
the direction indicated by the arrow (53). FIG. 11 shows the
implanted replacement valve (51) positioned in the aortic valve
position.
Imaging Systems
[0049] An imaging system to view the operating field may be used at
any time or throughout the duration of the surgery. Imaging systems
are well-known to one of skill in the art and include
transesophageal echo, transthoracic echo, intravascular ultrasound
imaging (IVUS), or an injectable dye that is radiopaque.
Cinefluoroscopy may also be utilized. In one embodiment, the
imaging system is deliverable through a catheter or cannula to the
operating field.
[0050] Intravascular ultrasound (IVUS) uses high-frequency sound
waves that are sent with a device called a transducer. The
transducer may be coupled to the delivery member of the present
invention. In this arrangement, the sound waves bounce off of the
walls of the vessel or heart and return to the transducer as
echoes.
[0051] In one embodiment of the present invention, a delivery
member may include at least one ultrasound transducer to provide an
image of the target site before, during, and after valve
implantation. FIG. 12 shows another embodiment of the delivery
member of present invention. In this embodiment, the delivery
member comprises an inner member (49A) that is retractable within
the lumen of an outer member (49B). Upon deployment of the delivery
member (40), the distal end (44) of the inner member (49A) is
exposed past the end (45) of the outer member (49B).
[0052] The distal end (44) of the inner member comprises an
expandable balloon (41) in fluid communication with the fluid
infusion mechanism (48) and the handle (43) of the delivery member,
by which the balloon (41) may be either inflated or deflated. The
inner member (49A) of the delivery member (40) further comprises
ultrasound transducers (47) adjacent to the expandable balloon (41)
and a tip or distal attachment (42) which is adapted to receive a
variety of auxiliary devices to assist in the valve replacement
procedure. Such auxiliary devices may include a distal embolic
protection assembly, a temporary valve, an imaging system, a valve
removal system, a valve decalcification system.
[0053] While ultrasound transducers disclosed here are located
adjacent to the balloon, it is appreciated that the ultrasound
transducer may be placed at any location on the delivery member, on
the balloon, and/or on the tip or distal attachment.
Valve Removal Systems
[0054] The present invention also provides a method or system for
removing the valve with a valve removal device by access through
the apical area of the heart. By way of example, the valve removal
may be accomplished as taught in co-pending U.S. patent application
Ser. Nos. 10/375,718 and 10/680,562, which are incorporated herein
by reference as if set forth in its entirety.
[0055] In one embodiment of the present invention, the method may
further comprise the step of removing at least a portion of the
patient's heart valve by means of a cutting tool that is disposed
on the delivery member. In another aspect of the present invention,
the cutting tool may be made of an electrically conductive metal
that provides radiofrequency energy to the cutting tool for
enhanced valve removal. The high frequency energy ablation is well
known in the art.
[0056] In another embodiment of the present invention, the delivery
member includes cutting means comprising a plurality of jaw
elements, each jaw element having a sharp end enabling the jaw
element to cut through at least a portion of the native valve. In
another aspect, the cutting means comprises a plurality of
electrode elements, wherein radiofrequency energy is delivered to
each electrode element, enabling the electrode element to cut
through at least a portion of the native valve. In a further aspect
of the present invention, the cutting means comprises a plurality
of ultrasound transducer elements, wherein ultrasound energy is
delivered to each transducer element enabling the transducer
element to cut through at least a portion of the native valve.
Valve Decalcification Systems
[0057] The formation of atherosclerotic plaques and lesions on
cardiovascular tissue, such as blood vessels and heart valves, is a
major component of cardiovascular disease. A variety of different
methods have been developed to treat cardiovascular diseases which
are associated with calcified atherosclerotic plaques and lesions.
Such methods include mechanical removal or reduction of the lesion,
such as bypass surgery, balloon angioplasty, mechanical
debridement, atherectomy, and valve replacement.
[0058] Calcified atherosclerotic plaques and lesions may also be
treated by chemical means which may be delivered to the affected
area by various catheter devices. For example, U.S. Pat. No.
6,562,020 to Constantz et al. discloses the treatment of vascular
calcified lesions by using an acidic dissolution solution and a
catheter fluid delivery system capable of localized flushing a
vascular site. Suitable catheter devices include those described in
U.S. Pat. No. 6,562,020, which is incorporated herein by reference
as if set forth in its entirety.
[0059] Accordingly, in another embodiment of the present invention,
the methods and devices of the present invention may be adapted to
provide a valve decalcification system, wherein the delivery member
is capable of providing the dissolution solution to the treatment
site by access through the apical area of the heart. Suitable
dissolution solutions are known in the art and are generally
characterized as those which are capable of increasing the proton
concentration at the treatment site to a desired level sufficient
to at least partially dissolve the mineral component of a calcified
atherosclerotic lesion.
[0060] The delivery member may be a catheter that is configured
with means to both introduce and remove the dissolution solution to
the treatment site. The delivery member may also provide means for
isolating the treatment site to prevent the dissolution solution
from entering into the patient's circulatory system. Such means for
isolating the treatment site may include a barrier, such as a dual
balloon system on the catheter that inflate on both sides of the
treatment site.
Temporary Valve
[0061] During valve replacement surgery, the function of the native
valve being replaced is halted and the natural fluid flow blood in
the heart is therefore disrupted. This, in turn, may result in
significant backflow blood pressure in the heart and vessels. There
is therefore a need to prevent or reduce the backflow blood
pressure that results when the natural valve function is halted
during replacement valve surgery.
[0062] The present invention provides a means of providing a
temporary valve either before or concomitantly with the delivery of
a replacement heart valve.
[0063] In one embodiment of the present invention, the delivery
member comprises a temporary valve, which may be deployed at a
desired location in a collapsed state, expanded and secured to the
walls of a heart or blood vessel, and then re-collapsed and removed
from the body after completion of the valve replacement surgery.
The temporary valve may be provided as a tip attachment to a
deliver member comprising the replacement valve. Alternatively, the
temporary valve may be disposed on a separate delivery member in a
manner similar to the replacement heart valve.
[0064] In a preferred embodiment of the present invention, the
temporary valve is deployed at a location that is sufficiently
close to the non-functioning valve. The location of the temporary
valve may be placed either upstream or downstream of the
non-functioning valve.
Distal Embolic Protection Assemblies
[0065] In valve repair or replacement surgery, manipulation of the
heavily calcified valves may result in dislodgment of calcium and
valve or other surrounding tissue, with subsequent embolization and
blockage. Although atheromatous debris most frequently embolizes in
the brain, other affected body sites include the spleen, kidney,
pancreas, and gastrointestinal tract. Embolization and blockage to
these peripheral organs can lead to tissue ischemia or death. A
need therefore exists for safely containing embolic material during
cardiovascular surgery.
[0066] In one embodiment of the present invention, a valve-filter
assembly is provided. This valve-filter assembly may be implanted
downstream from the site before surgery is to be performed. A
preferred embodiment of the valve-filter assembly is depicted in
FIG. 13, which shows a valve-filter assembly (61) positioned in the
aorta (22) and downstream of the aortic valve (23). The temporary
valve-filter assembly (61) is comprised of a temporary valve (62)
and a filter (63) extending therefrom. The valve-filter assembly
provides distal embolic protection and may be delivered by a
catheter or cannula or any conventional method to the downstream
side of the native aortic valve (23). After the temporary
valve-filter assembly is positioned at a desired location (64), it
is deployed to serve the dual functions of a temporary check valve
and a filter to capture any loose emboli or debris during
surgery.
[0067] A valve is included in the distal embolic protection
assembly to provide the dual function of acting as a temporary
valve during valve replacement surgery and preventing embolic
material from escaping out from the filter. Adding a one-way valve
at the inflow of a filter prevents embolic material from escaping,
thus reducing the incidence of embolization and blockage. A valve
would concurrently provide a temporary valve for use during valve
surgery. Combining both a filter and a valve in the same
arrangement also creates a more compact device allowing more space
for conducting other procedures. In aortic repair and replacement
surgeries, for example, there is limited space in between the
aortic valve and the innominate branch. Combining a filter and a
valve in a compact device allows more space for devices used for
the valve repair or replacement procedure.
[0068] A difficulty inherent in the percutaneous implantation of
valve-filter devices, as described above, is the limited amount of
space that is available within the vasculature. The device must be
dimensioned and configured to permit it to be introduced into the
vasculature, maneuvered therethrough and positioned downstream of
the treatment site. This may involve passage through significant
convolutions at some distance from the initial point of
introduction. Once in position, the device must be deployable to a
sufficiently large cross-section to effectively strain
substantially all of the blood passing therethrough without
unacceptably reducing its flow rate. Additionally, the use or the
presence of such device must not interfere with the treatment of
the vasculature site, nor may the treating device interfere with
the function of the embolic capture device.
[0069] Moreover, it is crucial that material captured by the
filters described above are contained and not allowed to leave the
proximity of the filter. In valve repair surgery, for example, it
is important that material dislodged during surgery and trapped by
a filter placed in between the aortic valve and innominate branch
is not allowed to leave the filter during back flow and hence enter
the coronaries. Preventing debris from leaving the filter is
especially important when larger particles are present that does
not easily attach to the filter material.
[0070] The filter of the valve-filter assembly may be a mesh of any
size and shape required to trap all of the embolic material while
still providing sufficient surface area for providing satisfactory
blood flow during use. The filter may be a sheet or bag of
different mesh sizes. In a preferred embodiment, the mesh size is
optimized taking into consideration such factors as flow
conditions, application site, size of filter bag, and rate of
clotting.
[0071] Although the invention has been described with reference to
preferred embodiments and specific examples, those of ordinary
skill in the art will readily appreciate that many modifications
and adaptations of the invention are possible without departure
from the spirit and scope of the invention as claimed
hereinafter.
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