U.S. patent application number 14/304223 was filed with the patent office on 2014-10-02 for methods and systems for cardiac valve delivery.
The applicant listed for this patent is Medtronic 3F Therapeutics, Inc.. Invention is credited to Bjarne Bergheim, Walberto Cueves, Jeffrey P. DuMontelle.
Application Number | 20140296973 14/304223 |
Document ID | / |
Family ID | 37709147 |
Filed Date | 2014-10-02 |
United States Patent
Application |
20140296973 |
Kind Code |
A1 |
Bergheim; Bjarne ; et
al. |
October 2, 2014 |
METHODS AND SYSTEMS FOR CARDIAC VALVE DELIVERY
Abstract
The present invention provides systems and methods for the
repair, removal, and/or replacement of heart valves. The methods
comprise introducing a delivery system into the heart, wherein a
prosthesis is disposed on the delivery member attached to the
delivery system, advancing the prosthesis to the target site, and
disengaging the prosthesis from the delivery member at the target
site for implantation. The present invention also provides implant
systems for delivering a prosthesis to a target site in or near the
heart. In one embodiment of the present invention, the implant
system comprises a delivery system, an access system, and a
prosthesis.
Inventors: |
Bergheim; Bjarne; (Laguna
Hills, CA) ; Cueves; Walberto; (San Diego, CA)
; DuMontelle; Jeffrey P.; (Irvine, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Medtronic 3F Therapeutics, Inc. |
Irvine |
CA |
US |
|
|
Family ID: |
37709147 |
Appl. No.: |
14/304223 |
Filed: |
June 13, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11492486 |
Jul 24, 2006 |
8790396 |
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14304223 |
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60762909 |
Jan 27, 2006 |
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60740694 |
Nov 29, 2005 |
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60734429 |
Nov 8, 2005 |
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60717879 |
Sep 16, 2005 |
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60702892 |
Jul 27, 2005 |
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Current U.S.
Class: |
623/2.11 |
Current CPC
Class: |
A61F 2/2427 20130101;
A61F 2230/001 20130101; A61F 2/2433 20130101; A61F 2230/0065
20130101; A61F 2230/0067 20130101; A61F 2/013 20130101; A61F 2/2418
20130101; A61F 2/91 20130101; A61F 2230/008 20130101; A61F
2250/0039 20130101; A61F 2230/0006 20130101; A61F 2230/0069
20130101; A61F 2002/018 20130101 |
Class at
Publication: |
623/2.11 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1-52. (canceled)
53. A delivery system comprising: an elongated, rigid support
structure; a delivery member coupled to the support structure at a
distal portion of the support structure; a valve replacement
detachably positioned about the delivery member and configured to
be collapsed to temporarily reduce a valve diameter, the valve
replacement comprising a pliant prosthetic valve having an inlet
end, an outlet end, a plurality of leaflet portions, and a
plurality of commissural tabs positioned at the outlet end and
integrally formed with the leaflet portions; and a collapsible,
self-expanding stent positioned about an exterior of the valve, the
stent having a circular inflow rim and a circular outflow rim
connected by a plurality of longitudinal support posts, the
commissural tabs operably coupled to the longitudinal support
posts, wherein the rigid support structure is configured to
transmit longitudinal and rotational motion along its length
without twisting or bending along its length, wherein the delivery
member comprises a perfusion tube connecting a distal end and a
proximal end of the delivery member configured to allow blood flow
through the delivery member, and wherein the rigid support
structure terminates between the proximal end of the delivery
member and the distal end of the delivery member.
54. The delivery system of claim 53, wherein the self-expanding
stent comprises a shape memory alloy.
55. The delivery system of claim 54, wherein the shape memory alloy
is Nitinol.
56. The delivery system of claim 53, wherein the rigid support
structure is selected from the group consisting of a solid rod, a
hollow rod, a catheter with a guide stick, and a catheter with a
guide sleeve.
57. The delivery system of claim 53, wherein the delivery member
comprises a proximal portion, a middle portion, and a distal
portion, and wherein a cross-sectional area of the proximal portion
and a cross-sectional area of the distal portion are each greater
than a cross-sectional area of the middle portion.
58. The delivery system of claim 57, wherein the valve replacement
is disposed about the middle portion of the delivery member.
59. The delivery system of claim 53, wherein the valve replacement
is configured to be compressed to reduce the valve diameter by up
to about 90%.
60. The delivery system of claim 53, further comprising a delivery
sleeve disposed about the delivery member.
61. A scapus delivery system comprising: an elongated, rigid
scapus; and a delivery member positioned about the scapus, wherein
the delivery member comprises a perfusion tube connecting a distal
end and a proximal end of the delivery member configured to allow
blood flow through the delivery member, and wherein the scapus
terminates between the proximal end of the delivery member and the
distal end of the delivery member.
62. The delivery system of claim 61, further comprising a
prosthetic valve positioned about the delivery member, the
prosthetic valve comprising: a collapsible, self-expanding stent;
and a plurality of leaflets.
63. The delivery system of claim 62, wherein the prosthetic valve
is contained by the delivery member.
64. The delivery system of claim 62, further comprising a delivery
sleeve disposed about the delivery member.
65. The delivery system of claim 61, wherein the scapus extends
within the perfusion tube.
66. A delivery system comprising: an elongated, rigid support
structure; a perfusion tube attached to the support structure; a
delivery member disposed around the perfusion tube; and a
prosthetic valve positioned about the delivery member, the
prosthetic valve comprising: a collapsible, self-expanding stent;
and a plurality of leaflets; wherein the perfusion tube extends
from a proximal end to a distal end of the delivery member and is
configured to allow blood flow through the delivery member, and
wherein the rigid support structure terminates between the proximal
end and the distal end of the delivery member.
67. The delivery system of claim 66, wherein the prosthetic valve
is crimped onto the delivery member.
68. The delivery system of claim 66, further comprising a delivery
sleeve disposed about the delivery member.
69. The delivery system of claim 66, wherein the support structure
is attached to an exterior surface of the perfusion tube.
70. The delivery system of claim 66, wherein the delivery member
comprises a proximal portion, a middle portion, and a distal
portion, wherein a cross-sectional area of the proximal portion and
a cross-sectional area of the distal portion are each greater than
a cross-sectional area of the middle portion, and wherein the valve
replacement is disposed about the middle portion of the delivery
member.
71. The delivery system of claim 66, wherein the support structure
comprises a material that substantially resists bending and
torsion.
72. The delivery system of claim 66, wherein the delivery member
comprises one or more holes at the proximal end and one or more
holes at the distal end to allow blood flow through the perfusion
tube.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Provisional Application
Ser. No. 60/702,892 filed Jul. 27, 2005; Provisional Application
Ser. No 60/717,879 filed Sep. 16, 2005; Provisional Application
Ser. No. 60/734,429 filed Nov. 8, 2005; Provisional Application
Ser. No. 60/740,694 filed Nov. 29, 2005; and Provisional
Application Ser. No. 60/762,909 filed Jan. 27, 2006; all of which
are incorporated herein by reference
FIELD OF THE INVENTION
[0002] The present invention relates generally to methods and
systems for cardiovascular surgery.
[0003] 1. Background of the Invention
[0004] 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.
[0005] 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 cut
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 typically be placed
on cardiopulmonary bypass for the duration of the surgery.
[0006] 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 an
extended hospitalization and painful recovery period for the
patient.
[0007] Minimally invasive valve replacement procedures have emerged
as an alternative to open-chest surgery. Wikipedia Encyclopedia
defines a minimally invasive medical procedure as one that is
carried out by entering the body through the skin or through a body
cavity or anatomical opening, but with the smallest damage possible
to these structures. Two types of minimally invasive valve
procedures that have emerged are percutaneous valve procedures and
trans-apical valve procedures. Percutaneous valve procedures
pertain to making small incisions in the skin to allow direct
access to peripheral vessels or body channels to insert catheters.
Trans-apical valve procedures pertain to making a small incision in
or near the apex of a heart to allow valve access. The distinction
between percutaneous valve procedures and minimally invasive
procedures is also highlighted in a recent position statement of
the Society of Thoracic Surgeons (STS), the American Association
for Thoracic Surgery (AATS), and the Society for Cardiovascular
Angiography and Interventions (SCAI; Vassiliades Jr. T A, Block P
C, Cohn L H, Adams D H, Borer J S, Feldman T, Holmes D R, Laskey W
K, Lytle B W, Mack M F, Williams D O. The clinical development of
percutaneous heart valve technology: a position statement by the
Society of Thoracic Surgeons (STS), the American Association for
Thoracic Surgery (AATS), and the Society for Cardiovascular
Angiography and Interventions (SCAI). J Thorac Cardiovasc Surg.
2005; 129:970-6). Because minimally invasive approaches require
smaller incisions, they generally allow for faster patient recovery
with less pain and bodily trauma. This, in turn, reduces the
medical costs and the overall disruption to the life of the
patient.
[0008] The use of minimally invasive approaches, 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, percutaneous heart surgery offers a surgical field that is
only as large as the diameter of the blood vessel used for access.
Consequently, the introduction of tools and prosthetic devices
becomes a great deal more complicated as compared to open-chest
surgeries. 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, before placement can be made at the intended
site.
[0009] Andersen et al. describe a valve prosthesis implanted in a
body channel by a way of catheterization in U.S. Pat. Nos.
5,411,442; 5,840,081; 6,168,614; and 6,582,462; and U.S. patent
application Ser. No. 10/268,253, hereby incorporated by reference
in their entirety. Catheters are hollow flexible tubes which can be
passed inside blood vessels to the heart for diagnostic and
treatment purposes. The delivery of catheter expanded valves
through body channels such as that described by Andersen et al. is
thus dependent on instruments of sufficiently small diameters, as
well as adequate length and flexibility to navigate blood
vessels.
[0010] Minimally invasive trans-apical valve replacement procedures
have emerged as an alternative to both open-chest surgery and
percutaneous valve surgeries. Bergheim et al. present improved
methods and systems for cardiac valve delivery in U.S. patent
application Ser. Nos. 60/702,892 and 10/831,710, hereby
incorporated by reference in their entirety. Methods and systems
for the repair, removal, and/or replacement of heart valves through
the apex of the heart are described. This is an improvement over
minimally invasive percutaneous approaches attempting insertion
into the vasculature as the trans-apical approach is not limited by
the space that is available within the vasculature. Trans-apical
delivery is also closer to the heart than catheter-based
procedures.
[0011] In-vivo studies have shown that catheter-based valve
delivery instrumentation may not be well adapted for trans-apical
procedures. When inserting balloon catheters, as described in U.S.
Pat. No. 6,582,462 and U.S. patent application Ser. No. 10/831,770,
it is difficult to steer the balloon and the valve into position
resulting from the lack of rigidity and the inherent flexibility of
catheters. This is especially true in minimally invasive
trans-apical valve procedures. By their very nature, catheters are
designed to be long, flexible and bendable to navigate long
distances through the vasculature. Catheters are also frequently
susceptible to twisting. As a result, catheters are typically thin
and made of flexible materials such as plastics or polymers.
Catheters are also designed to be disposed on guidewires to better
direct the catheter to the correct location. Even so, it is
difficult to steadily and accurately deliver tools and devices over
long distances. This is especially true in high flow situations
such as a beating heart and in places offering the catheters a
substantial amount of space to move within. Correct and accurate
placement of a heart valve requires both accurate longitudinal
positioning as well as rotational positioning. It is important to
correctly place the valve as much as possible into a position that
mimics that of the native valve to maximize durability and
function. It is also important to prevent placement of the valve in
a manner that blocks the left and right coronary outflow (as in the
case of the aortic valve). There is hence a need to accurately
maneuver and steer the valve during implantation. There is also a
need for a device that is more suitable for delivering valves
during trans-apical procedures.
[0012] During balloon-inflation of a flexible leaflet valve, such
as a stented tissue valve, it is desired that the valve remain on
the balloon until it is firmly positioned at the site of
implantation. In the case of balloon-expandable valves, there is
hence a need for devices designed to make sure the valve stays on
the balloon during inflation.
[0013] Bergheim further presents methods and assemblies for distal
embolic protection in U.S. patent application Ser. No. 10/938,410,
hereby incorporated by reference in its entirety. Here, Bergheim
describes distal embolic protection assemblies for use during
trans-apical valve surgery. In order to accommodate a distal
embolic protection assembly alongside other valve insertion and
replacement devices, it is important that the distal embolic
protection assembly collapses down to a substantially small
diameter to minimize the space it occupies
[0014] Macoviak et al. present a filter catheter used to capture
potential emboli within the aorta during heart surgery and
cardiopulmonary bypass in U.S. patent application Ser. No.
10/108,245, hereby incorporated by reference in its entirety. The
filters described by Macoviak are adapted for use during
cardiopulmonary bypass, and not during beating heart surgery. The
filters described by Macoviak are also intended to be inserted
through the femoral artery and further fail to incorporate a
temporary valve, useful for capturing large amounts of debris while
performing beating heart surgeries. There is hence a need for a
filter system better suited for percutaneous and trans-apical valve
surgeries.
[0015] Accordingly, while open-heart 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 THE INVENTION
[0016] The present invention provides methods and systems for
performing cardiovascular surgery, wherein access to the heart or
great vessels is provided through the heart muscle. In preferred
embodiments, access 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.
[0017] 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 the
present invention permit direct access to the heart and great
vessels through the apex, they are not limited by the size
constraints which are presented by minimally invasive percutaneous
valve surgeries. While access to the heart through peripheral (e.g.
femoral, jugular, etc) vessels in percutaneous methods are limited
to the diameter of the vessel (approximately 1 to 8 mm), access to
the heart through the apical area is significantly larger
(approximately 1 to 25 mm or more). 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.
[0018] Accordingly, it is one object of this invention to provide
methods and devices for the repair, removal, and/or replacement of
valves or their valve function by access through the heart muscle,
particularly through the apical area of the heart. It should be
noted that while reference is made herein of trans-apical
procedures, it is intended for such procedures to encompass access
to the heart through any wall thereof, and not to be limited to
access through the apex only. While the apical area is particularly
well suited for the purposes of the present invention, for certain
applications, it may be desirable to access the heart at different
locations, all of which are within the scope of the present
invention.
[0019] In one 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 system into
the heart, preferably at or near the apex of the heart, wherein a
prosthesis is disposed on the delivery member attached to the
delivery system, advancing the prosthesis to the target site, and
disengaging the prosthesis from the delivery member at the target
site for implantation. In another embodiment of the current
invention, a method for delivering a prosthesis to a pre-existing
man-made valve within or near a heart is provided.
[0020] The present invention also provides an implant system for
delivering a prosthesis to a target site in or near a heart. In one
embodiment of the present invention, the implant system comprises a
delivery system, an access system, and a prosthesis. In one
embodiment of the present invention, the access system is a trocar,
cannula, or other suitable device to penetrate the heart,
preferably at or near the apex of the heart; and the delivery
system is substantially rigid and movably disposed within the
trocar, wherein a prosthetic valve is disposed on the delivery
member attached to the delivery system. In one embodiment of the
present invention, the delivery system is termed a Scapus.TM.
system. The term "Scapus.TM." denotes a slender or elongated rod
shaped support structure that is substantially rigid. The term
substantially rigid implies structural stability to withstand fluid
pressures and other forces without unintended deformation. On the
other hand, the. Scapus.TM. may encompass junctions or other means
of controlled bending to allow for directional control by the
operator at predetermined points along the length of the
Scapus.TM.. In one embodiment of the current invention, the
delivery system comprises a Scapus.TM. and a delivery member.
[0021] The delivery system may be used to deliver a variety of
prosthetic heart valves, including stented and stentless tissue
valves. In one embodiment of the present invention, the delivery
member comprises a mechanical or inflatable expanding member to
facilitate implantation of the prosthetic valve at the target site.
In another embodiment of the present invention, the delivery member
is a balloon. In another embodiment of the present invention, the
delivery member is a device used to expand folded valves. In yet
another embodiment of the present invention, the delivery member
may comprise an inflatable balloon member, whose distal and
proximal ends have substantially larger cross-sectional areas than
the portion of the balloon covered by the prosthesis, to prevent
prosthesis migration. In a further embodiment of the present
invention, the delivery system may comprise a duct or perfusion
tube to allow blood flow through the delivery member during the
procedure.
[0022] It is a further object of the current invention to provide
systems and methods for converting a catheter into a Scapus.TM.
delivery system. In one embodiment of the current invention, a
substantially thin, stiff guide-stick is inserted into the catheter
to give it similar characteristics as a Scapus.TM.. In another
embodiment of the current invention, a substantially thin, stiff
guide-sleeve slides on the outside of a catheter to give it similar
characteristics as a Scapus.TM..
[0023] The delivery systems described herein may be used to deliver
prosthetic valves to all four valves of the heart including the
aortic valve, mitral valve, tricuspid valve, and pulmonary valve.
Different anatomical features for the different heart valves
(bicuspid vs. tricuspid valves) may call for different design heart
valves. Therefore, in one embodiment of the present invention, the
prostheses are designed to match the anatomy of the target valve
position. In another embodiment of the current invention, the
prosthesis is composed of a tissue valve mounted in a stent.
[0024] One group of patients that will benefit from a trans-apical
procedure is patients who have had previous valve replacements, and
where replacement valves are failing. Rather than performing yet
another open-chest procedure, many of these patients may be
candidates for trans-apical valve replacements. This is especially
the case for older patients who may not tolerate the stress of a
new open-chest procedure. For these patients, who have a failing
valve, one may seat the new trans-apical delivered prosthesis
inside the failing valve. Therefore, in one embodiment of the
present invention, the new prosthesis matches the configuration of
the failing valve. Some patients who have had previous valve
replacements, and whose valve replacement valves are failing may
also be candidates for percutaneous valve procedures. For these
patients, who have a failing valve, one may seat the new
percutaneously delivered prosthesis inside the failing valve.
[0025] The present invention also provides for devices and methods
for providing distal embolic protection and a temporary valve. In
one embodiment of the present invention, the distal embolic
protection system provides a filter member for trapping embolic
material that concurrently functions as a temporary valve. The
filter and temporary valve 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,
the filter assembly is implanted in the heart or great vessel of
the heart, downstream from the surgical site.
[0026] In one embodiment of the present invention, a valvuloplasty
balloon is inflated to increase the effective orifice area of a
heart valve. In another embodiment of the present invention, the
valvuloplasty balloon slides over the guide wire or actuation
sleeve connected to the distal embolic protection device.
[0027] Since a transapical procedure does not provide direct line
of sight, sufficient imaging of the heart, valves, and other
structures is important to provide diagnostics, guidance and
feed-back during the procedure. A Scapus.TM. delivery system may be
of a larger diameter than that of a catheter and is thus better
suited for containing imaging transducers. Thus in one embodiment
of the present invention, an imaging transducer is placed onto the
delivery system. In another embodiment of the present invention, an
external imaging transducer may be provided to view the operating
field. Imaging systems may be used at any time or throughout the
duration of the surgery. Imaging systems are well-known to those
skilled in the art and include transesophageal echo, transthoracic
echo, intravascular ultrasound imaging (IVUS), intracardiac echo
(ICE), or an injectable dye that is radiopaque. Cinefluoroscopy may
also be utilized.
[0028] In another embodiment of the present invention, a
positioning balloon is used to help position the Scapus.TM.
correctly such that the new prosthesis (or alternatively other
tools) land in the proper location.
[0029] In yet another embodiment of the present invention, 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 system.
[0030] 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 system
is capable of providing a dissolution solution to the treatment
site by access through the apical area of the heart. The delivery
system may be a catheter or a Scapus.TM. that is configured with
means to both introduce and remove the dissolution solution to the
treatment site. The delivery system 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 inflates on both sides of the
treatment site.
[0031] The present invention provides methods and systems for
creating a calcified animal model for use in the development and
testing of cardiac valves.
[0032] Although many of the above embodiments are referenced with
respect to the aortic valve in the heart, the current invention may
also be utilized for procedures related to the mitral valve,
tricuspid valve, and the pulmonary valve.
[0033] 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
[0034] FIG. 1 is a partial front view of a patient's chest showing
a prosthesis introduced into the apex of the heart through the
fifth intercostal space using an implant system.
[0035] FIG. 2 depicts a linear penetrating the apex of the heart
and into the left ventricle.
[0036] FIG. 3 shows two independent balloon delivery members
contained on the Scapus.TM. delivery system for providing both
valvuloplasty and valve delivery.
[0037] FIG. 4 shows a prosthetic valve disposed onto a "dog-bone"
shaped balloon.
[0038] FIG. 5 shows a Scapus.TM. delivery system and a distal
embolic protection assembly.
[0039] FIG. 6 shows a Scapus.TM. delivery system and a distal
embolic protection assembly.
[0040] FIG. 7 shows the distal embolic protection system positioned
in the aorta and inserted through the femoral artery.
[0041] FIG. 8 shows a prosthetic valve implanted in the heart.
[0042] FIG. 9 shows a Scapus.TM. delivery system.
[0043] FIG. 10 shows a Scapus.TM. delivery system.
[0044] FIG. 11 shows a close-up of a balloon delivery member of a
Scapus.TM. delivery system.
[0045] FIG. 12 shows a distal embolic protection subsystem.
[0046] FIG. 13 shows a temporary valve distal embolic protection
system.
[0047] FIG. 14 shows a dual balloon system for providing a valve
decalcification system.
[0048] FIG. 15 shows an exploded view of a heart valve implanted
inside a previously implanted heart valve.
[0049] FIG. 16 shows an a heart valve implanted inside a previously
implanted heart valve.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] FIGS. 1 through 16 show embodiments of the methods and
systems of the present invention for the repair, removal and/or
delivery of prosthetic valves, and also for providing distal
embolic protection and a temporary valve during cardiovascular
procedures.
Valve Delivery Method and Implantation System
[0051] FIG. 1 is a partial front view of the chest 11 of a patient
10 and shows the position of a surgical tool 29 in relation to
other anatomical landmarks, such as the sternum 13, xiphoid 14,
ribs 15, and heart 12. A surgical tool 29 is depicted as entering
the body cavity through the fifth intercostal space 16 and through
the apex of the heart 12. The surgical tool 29 is seen inserted
through an access system 31. The surgical tool 29 may contain
devices or systems used for surgical procedures in or on the heart
or the greater vessels of the heart. In one embodiment of the
current invention, the surgical tool 29 is a delivery system. In
another embodiment of the current invention, the surgical tool 29
may be a distal embolic protection device. The surgical tool 29 may
enter the body cavity through various other locations 17A, 17B and
17C, in the chest 11. In another embodiment of the current
invention, the surgical tool 29 may be a plurality of devices. In
one embodiment of the current invention, the surgical tool 29 is
both a delivery system and a distal embolic protection system.
[0052] In one embodiment of the present invention, the implant
system comprises an access system, delivery system, and a
prosthesis. In one embodiment of the current invention, the
prosthesis is a heart valve prosthesis. In another embodiment of
the current invention, the access system 31 is a trocar, cannula,
or other suitable device for penetrating the apex 18 of the heart
12. In another embodiment of the current invention, the delivery
system is composed of a delivery member, wherein the prosthetic
valve is disposed on the delivery member. In another embodiment of
the current invention, the delivery system is substantially rigid.
In yet another embodiment of the current invention, the
substantially rigid support structure of the delivery system is
called a Scapus.TM.. Inherent in its definition, the term
Scapus.TM. implies a rigid support structure with other devices,
tools, and assemblies attached to it. In one embodiment of the
current invention, the delivery member of the delivery system is
attached to the Scapus.TM..
[0053] The delivery system described in the current invention
presents major advances over the use of catheters as delivery
systems for procedures in close vicinity of the heart. By their
very nature, catheters are designed to be flexible to navigate long
distances. Catheters must also be able to twist and bend to move
through bends in the vasculature, such as those encountered in
percutaneous procedures. Catheters are also designed to be disposed
on guidewires to better direct the catheter to the correct
location. Even with the use of guidewires, it is difficult to
steadily and accurately deliver tools and devices over long
distances. This is especially true in high flow situations such as
a beating heart procedure. Correct and accurate placement of a
heart valve requires both accurate longitudinal positioning as well
as rotational positioning. It is important to correctly place the
valve as much as possible into a position that mimics that of the
native valve to maximize durability and function. It is also
important to prevent placement of the valve in a manner that blocks
the left and right coronary outflow (as in the case of the aortic
valve).
[0054] Accurate delivery of cardiac valves in trans-apical
procedures requires accurate and precise longitudinal and
rotational positioning. Longitudinal positioning implies
positioning along the length of the aorta. Rotational positioning
implies rotational positioning around the lengthwise direction of
the aorta. The route from the apex of the heart to all four cardiac
valves is also a substantially straight line, meaning that the
maneuvering features such as bending, twisting, and torsion of a
catheter are not typically desired. In fact, the inherent
maneuvering features of a catheter are disadvantageous in this
procedure as it allows bending and torsion and is not able to hold
the delivery member in place during valve implantation. The blood
flow and pressure inherent in a beating heart procedure in
combination with a catheter delivery system therefore does not
allow accurate and precise delivery of prosthetic valves.
[0055] An object of the present invention is therefore to provide a
delivery system that is substantially rigid to resist any
unintended bending and torsion. A Scapus.TM., in contrast to a
catheter, provides sufficient rigidity to accurately and precisely
deliver a prosthesis during a beating heart procedure. A Scapus.TM.
delivery system is designed not twist or bend unless intended by
the operator. The Scapus.TM. of the present invention can
incorporate junctions or other means of bending at predetermined
points to allow the operator to adjust the direction or angle of
the delivery path in a controlled fashion.
[0056] In one embodiment of the present invention, the Scapus.TM.
provides rigid support between the operator and the distal portion
of the delivery system located in the heart. In contrast to
catheter delivery systems, a Scapus.TM. delivery system may
incorporate a larger cross-sectional area since access through the
heart walls provides a larger access port diameter (in some
instances up to 25 mm or more) compared with the vasculature (0 to
8 mm or less).
[0057] In one embodiment of the current invention, the Scapus.TM.
is made of a material that substantially resists bending and
torsion. One example of such a material is stainless steel or
substantially strong polymer plastics.
[0058] In one embodiment of the current invention, the Scapus.TM.
is a solid rod. In yet another embodiment of the current invention,
the Scapus.TM. is a hollow rod. A Scapus.TM. may contain one or
more lumens for moving fluid. A Scapus.TM. may also contain
actuating members such as rods, wires, guidewires, or catheters. A
Scapus.TM. may also conduct or transmit electricity or electrical
signals and may also transmit light or light signals. A Scapus.TM.
may also transmit radiation or other forms of energy such as
ultrasound, ultraviolet light, infrared light, or gamma rays.
[0059] A catheter used for percutaneous valve procedures are
typically longer than 50 cm to navigate through the vasculature. By
contrast, the Scapus.TM. length can be less than 50 cm. In
preferred embodiments of the present invention, the length of the
Scapus.TM. can be about 15-30 cm in total, of which about 10 cm may
be inserted into heart, and the remaining length left outside.
[0060] The methods and systems of the present invention may be used
to implant a variety of heart valve prosthesis known in the art,
including stented and stentless tissue valves. The methods and
systems of the present invention may also be used to implant a
variety of stents. In one embodiment of the present invention, the
prosthetic delivery member is located towards the distal end of the
delivery system. Stented valves may be expandable by mechanical or
balloon expansion devices, or they may be self-expanding.
Self-expanding stents may be constructed from elastic materials
such as memory shaped metal alloys. An example of a memory shaped
metal alloy is that of Nitinol. The valves are expanded using the
valve expansion member located on the delivery system. In one
embodiment of the present invention, the delivery member is a
mechanically actuated device used to expand stented valves. In
another embodiment of the current invention, the delivery member is
a balloon expansion device. In another embodiment of the present
invention, the delivery member is a balloon used for radial
expansion. In yet another embodiment of the current invention, the
delivery member contains a self-expandable heart valve. There are
numerous methods and systems for releasing a self-expandable heart
valve. One example in U.S. Pat. No. 6,682,558, hereby incorporated
by reference in its entirety.
[0061] Stented valves may also be expandable by unfolding the
valve. The valve may be unfolded by using a balloon or mechanical
expansion device. Alternatively, the folded valves may be
self-expanding. Self-expanding stents may be constructed from
elastic materials such as memory shaped alloys. The valves are
expanded using the valve expansion member located on the delivery
system. In one embodiment of the present invention, the delivery
member is a mechanically actuated device used to expand stented
valves that have been folded. In another embodiment of the current
invention, the delivery member is a balloon expansion device. In
such an embodiment, the balloon and stented valve have been folded
together. When inflated, the balloon and stented valve return to
their original shape. When unfolding a stented valve using a
mechanical expansion device or a balloon, the stent making up the
stented valve is typically made from a non-memory shaped alloy.
Examples of suitable materials include stainless steel, polymers,
plastics, and non-memory shaped metals. In another embodiment of
the present invention, the delivery member is used to unfold
stented valves made from memory shaped alloys. In one embodiment of
the present invention, the delivery member consists of a hollow
tube in which the stented valve is placed into and a plate or
actuating mechanism just proximal to the valve used to push out the
valve out of the hollow tube.
[0062] 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.
[0063] 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. Yet another valve suitable for use in
connection with the present invention is disclosed in U.S. patent
application Ser. No. 10/680,071, hereby incorporated for reference
in its entirety.
[0064] Access systems suitable for use in connection with the
present invention typically comprise a hollow lumen and a first and
second ends. In one embodiment of the present invention, the access
system 31 is a trocar. The first end comprises a means for
penetrating the heart tissue and the second end comprises a port
through which the valve delivery system may be introduced into the
hollow lumen of the trocar and into the heart. FIG. 2 depicts an
access system 31 penetrating through the apex 18 of the heart 12.
The moving direction of the access system 31 as indicated by the
arrow 19. The access system 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.
[0065] In another embodiment of the present invention, the access
system 31 further comprises a valve disposed within its lumen. The
valve is designed to reduce significant backflow of blood out of
the heart 12 after the access system 31 is inserted into the
beating heart 12, while at the same time permitting the
introduction of the delivery member and other surgical devices in
through the access system 31. Other suitable access systems 31 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.
[0066] In one embodiment of the present invention, the operator
places a pursestring suture on the apex 18 of the heart 12 to
create a seal around the access system 31. Another embodiment of
the present invention allows the use of the Scapus.TM. delivery
system without an access system 31. It is contemplated that the
physician becomes familiar with the advantages of the present
invention and thus may find it unnecessary to use a trocar. In the
latter case, the distal embolic protection system and the delivery
system is placed directly through an incision in the apex 18 or
other area of the heart wall. In another embodiment of the current
invention, a delivery sleeve or delivery sheath is placed on the
delivery system.
[0067] In one embodiment of the present invention, an off-the-shelf
valvuloplasty balloon catheter is introduced through the access
system 31 into the apex 18 of the heart 12, positioning the balloon
of the catheter within the valve and valve annulus. Valvuloplasty
balloons are well known to anyone skilled in the art. Once the
balloon is placed within the valve, it may be inflated to widen a
stiff or narrowed heart valve (stenotic heart valve) improving
blood flow through the heart and to the rest of the body. Previous
methods for performing valvuloplasty required the insertion of a
catheter typically through the femoral artery or femoral vein 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.
[0068] In another embodiment of the present invention, the delivery
member of the delivery system described in the current invention is
used to valvuloplasty the diseased valve. In such an embodiment,
the delivery member of the delivery system is first guided to the
diseased heart valve and positioned within the valve and valve
annulus. After expanding the valve orifice, the delivery system is
withdrawn from the access system 31 and a new prosthetic valve is
placed onto the valve delivery system. The valve delivery system is
further introduced through the access system 31 and the delivery
member moved into position within the valve orifice to expand and
implant the valve.
[0069] In yet another embodiment of the present invention, two
independent delivery members are contained on the delivery system.
Such a system is shown in FIG. 3. Here, the delivery system 67
includes a Scapus.TM. 46, a perfusion tube 49, and two
independently operated balloon delivery members 90 and 91. Such a
configuration allows the delivery system 67 to be used both for
valvuloplasty and valve delivery. In such an embodiment, the most
distal delivery member 91 is first guided to the diseased heart
valve and positioned within the valve and valve annulus. After
expanding the valve orifice, the delivery system 67 is moved such
that the second most proximal delivery member 90, onto which the
prosthetic valve is placed, is moved within the valve and valve
annulus to expand and implant the valve. In a further embodiment of
the present invention, no perfusion tube 49 is present and the
balloons 90 and 91 are in intimate contact with the Scapus.TM. 46.
The use of two balloons 90 and 91 as shown in FIG. 3 is not only
practical in trans-apical valve procedures, but also in
percutaneous valve procedures. Thus, in one embodiment of the
present invention, the Scapus.TM. 46 shown in FIG. 3 is a catheter.
In a further embodiment of the foregoing embodiment, the catheter
is a multilumen catheter.
Balloon Systems and Implantation Methods Thereof
[0070] Regardless of the type of valve delivery member utilized, it
is important that the prosthetic valve remain securely attached to
the delivery member during implantation. This is especially true if
the operator accidentally or intentionally lowers the pressure in
the balloon (via a syringe, etc). Thus, the present invention
further provides balloons that are shaped such that the distal and
proximal ends of the balloon, not covered by the prosthetic valve,
are larger in area, and thus prevents migration of the valve. Such
a balloon may take the shape of a "dog-bone".
[0071] FIG. 4 shows a balloon 50 delivery member whose proximal end
70 and distal end 71 have a larger cross sectional area than the
middle portion of the balloon in intimate contact with the
prosthetic valve 100. FIG. 4 also shows a perfusion tube 49
extending through the balloon from the proximal end 70 to the
distal end 71 of the balloon delivery member 50 allowing fluid to
flow through the length of the balloon delivery member 50. In one
embodiment of the present invention, the balloon delivery member 50
does not contain a perfusion tube 49. The orientation of the
prosthetic valve 100 on the balloon delivery member 50 shown in
FIG. 4 in relation to the proximal end 70 and distal end 71 of the
balloon delivery member 50 depends on the implantation method in
relation tot he blood flow direction through the native valve. The
orientation shown in FIG. 4 is preferred for apical implantation.
In another embodiment of the present invention, the prosthetic
valve 100 is oriented the opposite direction on the balloon
delivery member 50.
[0072] In one embodiment of the present invention, the distal end
71 and proximal end 70 of the balloon delivery member 50 has a
material coating that has a larger coefficient of friction with the
prosthetic valve as opposed to the middle portion of the balloon
delivery member 50. In the case of a balloon delivery member 50, an
example of a material that has a larger coefficient of friction
with a prosthetic valve as compared to the balloon is cloth.
Increasing the roughness in the plastic making up the balloon will
also increase the coefficient of friction with the prosthetic
valve.
[0073] The "dog-bone" shape balloon delivery member 50 described
herein is not limited to Scapus.TM. delivery systems. Such balloons
can be utilized in any type of stent delivery. Thus, in one
embodiment of the present invention, the "dog-bone" balloon
delivery member 50 described herein may be utilized in any type of
stent or prosthetic valve delivery system. In one embodiment of the
present invention, the "dog-bone" balloon delivery member 50 is
utilized on a catheter valve delivery system, such as those used
for percutaneous valve delivery.
Delivery System and Methods
[0074] FIG. 5 depicts a delivery system 67 consisting of a
Scapus.TM. 46, balloon inflation tube 45, proximal balloon delivery
member connector 48, distal balloon member connector 51, perfusion
tube 49, and a balloon delivery member 50. In a preferred
embodiment of the present invention, the proximal balloon delivery
member connector 48 and the distal balloon delivery member
connector 51 have a hole or a plurality of holes allowing blood to
flow through the perfusion tube 49 and hence through the balloon
delivery member 50. In another preferred embodiment, the Scapus.TM.
46 comprises a substantially rigid solid rod. In one embodiment of
the present invention, the Scapus.TM. 46 and the balloon inflation
tube 45 are glued or fused together at a plurality of points along
the extent of the Scapus.TM. 46. In another embodiment of the
present invention, the Scapus.TM. 46 contains one or more inside
lumens. In yet another embodiment of the current invention, the
balloon inflation tube 45 is disposed within the Scapus.TM. 46. In
another embodiment of the current invention, the balloon inflation
tube 45 is one of the internal lumens of the Scapus.TM. 46. In yet
another embodiment of the current invention, the Scapus.TM. 46 may
be bent in a controlled fashion, using a bending force. As used
herein, bending force here means bending moment that can be created
by the user of the operators' hands. The Scapus.TM. 46 cannot be
bent by the much smaller forces imposed by the blood flow and the
beating heart. The Scapus.TM. 46 may further incorporate junctions
or other bending means that allow for operator-controlled bending
of the Scapus.TM. 46 at predetermined points.
[0075] FIG. 5 also shows a distal embolic protection assembly 68.
The distal embolic protection assembly consists of a frame 55 and a
porous bags 56. In one embodiment of the present invention, the
distal inlet portion of the filter mouth 53 includes a temporary
valve.
[0076] In one embodiment of the present invention, the delivery
system 67 is inserted through the trocar 31 into the left ventricle
21 and advanced towards the native aortic valve of the heart 12.
The delivery system 67 may be composed of a substantially rigid
Scapus.TM. 46 and a delivery member. The heart valve prosthesis 100
is disposed around the balloon delivery member 50 and delivered to
the target site for implantation. The length of balloon delivery
member 50 suitable for the purposes of the present invention will
depend on the height of the prosthetic valve 100 to be
implanted.
[0077] FIG. 6 shows a delivery system 67 comprising a perfusion
tube 49, balloon delivery member 50, and a Scapus.TM. 46. Here, the
Scapus.TM. 46 is rigidly attached to the perfusion tube 49. In one
embodiment of the current invention, the Scapus.TM. 46 has a lumen
that extends to the balloon delivery member 50 and serves to
inflate and deflate the balloon. The actuation sleeve 43 and
guidewire 41 is loosely disposed within the perfusion tube 49.
[0078] In one embodiment of the present invention, the distal
embolic protection assembly 68, actuation sleeve 43 and guidewire
41 within activation sleeve 43 is movably disposed within the
Scapus.TM. 46 of the delivery system 67 and balloon delivery member
50 shown in FIG. 6. In yet a further embodiment of the present
invention, the distal embolic protection assembly 68 may be
collapsed and moved through the Scapus.TM. 46 and balloon delivery
member 50. In one embodiment of the present invention, the delivery
system shown in FIG. 6 is inserted through the trocar 31 in two
steps: first the distal embolic protection assembly 68; second the
delivery system 67 and balloon delivery member 50. After having
introduced the trocar 31 through the apex 18 of the heart 12, the
distal embolic protection assembly 68 is moved in a collapsed
configuration through the trocar 31 and the left ventricle 21 and
placed downstream from the aortic valve. Once the distal embolic
protection assembly 68 is in position, the distal embolic
protection assembly 68 is expanded to seal the inside circumference
of the aorta. Expansion takes place by moving the actuation sleeve
43 relative to the guidewire 41. All circulation through the aorta
will hence have to be filtered in the porous bag 56 of the distal
embolic protection assembly 68. The guidewire 41 and actuation
sleeve 43 extends from the proximal side of the distal embolic
protection assembly 68 to the outside of the body 10 and is
accessible to the operator. In one embodiment of the present
invention, the actuation sleeve 43 may also be used as a guidewire
to move the Scapus.TM. 46 into position. Thus in one embodiment of
the current invention, the Scapus.TM. delivery system may be
loosely disposed on a guidewire 41. In yet another embodiment of
the present invention, the perfusion tube 49 functions as the
actuation sleeve 43 to open and collapse the distal embolic
protection catheter.
[0079] Distal embolic protection assemblies 68 may be introduced
through the apex 18 of the heart 12. Such embodiments are
summarized in co owned U.S. application Ser. No. 10/938,410, hereby
incorporated by reference in its entirety. Distal embolic
protection assemblies 68 may also be inserted through arteries such
as the femoral artery such as those disclosed by Macoviak, et al in
U.S. application Ser. No. 10/108,245, hereby incorporated for
reference in its entirety. In another embodiment of the present
invention, the distal embolic protection filter assembly 68 is
introduced through the femoral artery and moved to the aortic arch,
positioned just downstream of the aortic valve as shown in FIG. 7.
A delivery sheath 66 is used to collapse the filter assembly
composed of the filter frame 55 and the porous bag 56. In a further
embodiment of the current invention, a guidewire 65 is attached to
the frame 55 on the proximal side of the filter assembly 68 and
continues through the aortic valve and out through the trocar 31
and out through the body 10. The guidewire 65 may be used for
guiding the delivery system 67 into position through the trocar 31
and the apex 18 of the heart. The way the guidewire 65 is attached
to the mouth of the filter 55 is for illustrational purposes only.
Anyone skilled in the art will appreciate there are many different
ways of attaching a guidewire to the mouth 55 of the filter and
different opening and closing mechanism for the filter. Other
aortic filter systems described in prior art for femoral artery
insertion may also be adapted for this procedure.
[0080] In one embodiment of the current invention, the delivery
sheath 66 shown in FIG. 7 is a Scapus.TM. 46 delivery system. The
Scapus.TM. 46 delivery system may slide across the guidewire. The
porous bag 56 may also be inserted and removed through the delivery
system.
[0081] Once the distal embolic protection assembly 68 has been
placed into position, the Scapus.TM. 46 of the delivery system 67
slides over the actuation sleeve 43 through the apex 18 of the
heart 12. In one embodiment of the present invention, the delivery
system 67 slides over the guidewire 41 or 65, depending on the
configuration of the distal embolic protection assembly. The
balloon delivery member 50 is positioned in the aorta and within
the aortic valve and aortic valve annulus. In one embodiment of the
present invention, the distal embolic protection system 68 and
valve delivery system 67 is inserted through the apex 18
together.
[0082] A collapsed replacement heart valve prosthesis 100 is
disposed on the balloon delivery member 50. The delivery system 67
with the attached replacement prosthetic valve slides over the
actuation sleeve and is introduced into the port of the access
system 31 and through the apex 18 of the heart 12. The balloon
delivery member 50 with the attached heart valve prosthesis 100 is
positioned in the aorta and within the aortic valve and aortic
valve annulus. The balloon delivery member 50 is expanded by moving
fluid through the balloon inflation tube 45. The balloon inflation
tube 45 connects fluid to the balloon delivery member 50. In one
embodiment of the present invention, the device used to move fluid
through the balloon inflation tube 45 is a syringe. The balloon
delivery member 50 expands in a radial direction when filled with
fluid through the balloon inflation tube 45 causing the replacement
prosthetic valve 100 to exert force against the existing valvular
leaflets and the walls of the vessel.
[0083] In one embodiment of the present invention, the valve
replacement procedure described herein is done more than once. A
repeat procedure may, for example, be performed in patients who
cannot tolerate an open chest surgery.
[0084] Once the heart valve prosthesis 100 is implanted, the
balloon delivery member 50 is deflated and the valve delivery
system 67 is withdrawn from the body. The distal embolic protection
assembly 68 is further withdrawn from the body 10. In one
embodiment of the present invention, the distal embolic protection
assembly 68 and the valve delivery system 67 are withdrawn from the
body together. In one embodiment of the present invention, a distal
embolic protection assembly 68 is not utilized. In yet another
embodiment of the present invention, the distal embolic protection
assembly 68 is left in the body for some time (up to 7 days) after
the operation to make sure that the porous bag 56 of the distal
embolic filter assembly 67 has collected all the debris.
[0085] FIG. 8 shows an implanted heart valve prosthesis 100
positioned in the aortic valve position.
[0086] FIGS. 9, 10, and 11 show a Scapus.TM. delivery system
comprising a Scapus.TM. 46, luer fitting 62, perfusion tube 49 and
a dog-bone shaped balloon delivery member 50. The luer fitting 62
is attached to the proximal side of the Scapus.TM. 46 and may be
used to direct fluid for opening and closing the balloon delivery
member 50. The balloon delivery member 50 is tightly disposed
around the perfusion tube 49. The perfusion tube 49 is attached to
the Scapus.TM. 46. Fluid may flow through the luer fitting 62,
through the Scapus.TM. 46 and into the balloon delivery member 50
to inflate and deflate the balloon.
[0087] It is important to note that although the different
inventions described herein is typically described in reference to
trans-apical valve implantation, they may also be used in
non-beating heart surgeries. A Scapus.TM. delivery system, for
example, may also be used in a open surgery situation. Thus, in one
embodiment of the current invention, a Scapus.TM. delivery system
is used in non-beating heart surgeries. In another embodiment of
the current invention, a Scapus.TM. delivery system may be used in
an open chest surgery or robotic surgery.
Converting a Catheter to a Scapus.TM.: Systems and Methods
Thereof
[0088] The preferred delivery system for delivering heart valves
and tools in a trans-apical or trans-heart procedure is a
Scapus.TM. delivery system. If a Scapus.TM. delivery system is not
available, however, one may convert a catheter into a delivery
system that is similar to a Scapus.TM. delivery system.
[0089] In one embodiment of the current invention, a substantially
thin, stiff guide stick is inserted into the catheter to give it
similar characteristics as a Scapus.TM.. The guide-stick is loosely
disposed within the catheter and occupies the space that a
guidewire would otherwise occupy. But as opposed to a guidewire
that cannot resist bending, a guide-stick is substantially rigid
and can resist any unintended bending and torsion. A guide-stick
disposed within a catheter, in contrast to a catheter by itself,
provides sufficient rigidity such that the resulting delivery
system may more accurately and more precisely deliver a prosthesis
during a beating heart procedure. The resulting delivery system is
designed not to bend unless intended by the operator. The resulting
delivery system can incorporate junctions or other means of bending
at predetermined points to allow the operator to adjust the
direction or angle of the delivery path in a controlled
fashion.
[0090] In another embodiment of the current invention, a
substantially stiff guide-sleeve is loosely disposed on the outside
of a catheter to give it similar characteristics as a Scapus.TM.
delivery system. The catheter is loosely disposed within the
delivery sleeve. The described delivery sleeve is substantially
rigid and can resist any unintended bending and torsion. A
guide-sleeve loosely disposed on a catheter, in contrast to a
catheter by itself, provides sufficient rigidity such that the
resulting delivery system may more accurately and more precisely
deliver a heart valve prosthesis 100 during a beating heart
procedure. The resulting delivery system is designed not to bend
unless intended by the operator. The resulting delivery system can
incorporate junctions or other means of bending at predetermined
points to allow the operator to adjust the direction or angle of
the delivery path in a controlled fashion.
Method for Valve Crimping and Valve Preparation
[0091] In one embodiment of the present invention, the heart valve
prosthesis 100 is shipped to the operating room in an expanded
configuration. The heart valve prosthesis 100 is crimped down in
diameter using crimpers known to anyone skilled in the art while
the heart valve prosthesis 100 is loosely disposed around a
delivery member. The crimping process occurs with the operating
room or in vicinity of the operating room. The heart valve
prosthesis 100 is further delivered to the target site for
implantation.
[0092] In one embodiment of the current invention, the heart valve
prosthesis 100 is shipped to the operating room in a crimped
configuration. The heart valve prosthesis 100 is crimped at the
manufacturing facility in a careful, consistent, and controlled
manner. The heart valve prosthesis 100 may be crimped directly onto
a delivery member, such as a balloon delivery member 50.
Alternatively, the heart valve prosthesis 100 may be crimped down
to a size such that the internal diameter of the heart valve
prosthesis 100 matches the external diameter of the delivery
member. The heart valve prosthesis 100 remains in a crimped
configuration until the heart valve prosthesis 100 reaches the
operating room. Crimping the heart valve prosthesis 100 in a
controlled environment will minimize structural deterioration to
the heart valve prosthesis 100 and will simplify the procedure in
the operating room. When reaching the operating room, the crimped
heart valve prosthesis 100 is disposed around the delivery member,
and the heart valve prosthesis 100 is further delivered tot he
target site for implantation.
Imaging Systems
[0093] Since a transapical procedure does not provide direct line
of sight, sufficient imaging of the heart, valves, and other
structures is important to provide diagnostics, guidance and
feed-back during the procedure. A Scapus.TM. delivery may be of a
larger diameter than that of a catheter and is thus better suited
for containing imaging transducers. Thus in one embodiment of the
present invention, an imaging transducer is placed onto the
delivery system. In one embodiment of the current invention, the
imaging transducer is placed within the delivery member. In another
embodiment of the present invention, the imaging transducer is
placed just proximal and/or distal to the delivery member.
[0094] An external imaging transducer may be provided to view the
operating field and imaging systems may be used at any time or
throughout the duration of the surgery. The valvuloplasty assembly
may include IVUS or other imaging sensors. Such imaging technology
can be used to inspect native valve annulus and size the required
heart valve prosthesis 100 after valvuloplasty has been
completed.
[0095] Imaging systems are well-known to anyone skilled in the art
and include transesophageal echo, transthoracic echo, intravascular
ultrasound imaging (IVUS), intracardiac echo (ICE), or an
injectable dye that is radiopaque. Cinefluoroscopy may also be
utilized. The placement of imaging probes in relation to a balloon
delivery member 50 has previously been described in co-owned
PCT/US/04/33026 filed Oct. 6, 2004, incorporated by reference in
its entirety.
Valve Removal System
[0096] The present invention also provides a method or system for
removing the native 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 Serial Nos. 10/375,718 and 10/680,562, which are
incorporated herein by reference as if set forth in their
entirety.
[0097] 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 Scapus.TM.. 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.
[0098] 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.
[0099] A Scapus.TM. with a valve removal system disposed on it is
introduced through the apex and positioned substantially in the
vicinity of the aortic valve. The native valve leaflets and debris
(e.g. calcium and valve leaflets) are removed. The parts that are
not contained by the valve removal systems are caught in the distal
embolic protection filter.
Distal Embolic Protection System
[0100] The present invention also provides for devices and methods
for providing distal embolic protection during the procedure. FIG.
5 and FIG. 6 show examples of distal embolic protection assemblies
68 and its relation to the delivery system 67. It is important that
the distal embolic protection filter provides a means for trapping
embolic material and debris. In one embodiment, it is also desired
that the distal embolic protection filter provides a temporary
valve. The filter and temporary valve assembly prevents flush back
of blood, embolic material and debris, while still allowing fluid
flow into the filter during surgery. The temporary valve may also
temporarily do the work of an adjacent heart valve, such as the
aortic valve. Thus in one embodiment of the present invention, the
distal embolic protection assembly 68 provides a filter member for
trapping embolic material that concurrently functions as a
temporary valve.
[0101] Distal embolic protection assemblies 68 used in both
trans-apical and percutaneous procedures must be compressed and
expanded to allow entry into small blood vessels or other body
cavities. Combining both a one-way valve and a filter basket
mechanism requires a significant amount of hardware making it
difficult to compress the filter down sufficiently to be used
during trans-apical and percutaneous procedures.
[0102] FIG. 12 shows a sub-component of a distal embolic protection
filter system that incorporates both a filter and the function of a
temporary valve. The proximal mouth 73 of the filter consists of a
proximal frame 74 that pushes against and makes a seal with the
surrounding vasculature. The proximal frame 74 may, for example,
push and seal against the inner wall of the aorta, causing all
emboli and debris to flow through the filter assembly. In one
embodiment of the present invention, the proximal frame 74 is made
out of a shape memory alloy such as Nitinol, allowing it to expand
into position.
[0103] The distal end 76 of the filter sub-assembly is shown open.
In other words, debris not caught in the filter mesh 78 may
continue out through the distal end 76 of the filter sub-assembly,
moving past the distal frame 75. In one embodiment of the present
invention, the distal frame 75 is made out of a shape memory alloy
such as nitinol, allowing it to maintain an open configuration.
[0104] FIG. 13 shows three inter-connected filter sub-assemblies
shown in FIG. 12. Although three sub-assemblies are shown, any
number of two or more sub-assemblies will work. The length from the
proximal frame to the distal frame of each sub-assembly is slightly
different, thus separating the filters meshes of the different
filter sub-assemblies 78, 79, and 82. The proximal frame 74 is
shared by all the different filter sub-assemblies.
[0105] Thus, in one embodiment of the present invention, a
plurality of filter sub-assemblies are interconnected at the large
inlet of the filters, while the downstream sides of the
sub-assemblies have smaller openings allowing debris to flow
through. In one embodiment of the current invention, the outermost
filter-assembly is closed at the downstream end. As such, the
device provides less flow restriction as the blood flows into the
porous bags (i.e. downstream from the aortic valve) as opposed to
the reverse. This means that the device also functions as a one-way
valve.
Valve Decalcification Systems
[0106] 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
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 the valve replacement.
[0107] 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 by Constantz et al., which is incorporated herein by
reference as set forth in its entirety, discloses methods and
systems for dissolving vascular calcified lesions using an acidic
solution. A catheter delivers an acidic fluid to a localized
vascular site. Such a system may, for example, decalcify a
calcified heart valve by applying an acidic solution (such as
hydrochloric acid, etc.)
[0108] The current percutaneous anti-calcification system disclosed
by Constantz et al. is inserted through the femoral artery.
Insertion through the femoral artery is impractical in the case of
a trans-apical procedure as it requires another incision into the
patient. The system by Constantz et al. may be adapted such that
the delivery member controlling and holding the decalcification
system is moved from the proximal side (i.e. side of the operator
as in the case of femoral access) to the distal side.
[0109] 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 a Scapus.TM. system
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.
[0110] A trans-apical delivered Scapus.TM. system may also provide
means for isolating the treatment site to prevent the dissolution
solution from entering into the patient's circulatory system. Thus
in one embodiment of the current invention the decalcification
systems described and incorporated for reference above is adapted
to be disposed on a Scapus.TM. as opposed to a catheter. 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.
[0111] FIG. 14 shows such a delivery system where a multilumen
Scapus.TM. 46 connects to a perfusion tube 49 which in turn
connects two balloons, a proximal balloon 92 and a distal balloon
93. The two balloons are shown inflated and in intimate contact
with the walls of the aorta 94. In one embodiment of the present
invention, the perfusion tube 49 is not present and the proximal
balloon 92 and the distal balloon 93 are intimately in contact with
the Scapus.TM. 43. Fluid may flow through the Scapus.TM. 46 to
inflate the proximal balloon 92 and distal balloon 93 as well as
provide the dissolution solution to the treatment site confined by
the proximal balloon 92 and distal balloon 93.
Valve Within Man-Made Valve: Systems and Methods Thereof
[0112] It is one objective of the current invention to provide
systems and methods for implanting an expandable heart valve within
a target valve located within a heart. Such a procedure is
beneficial in older or diseased patients who have previously
received a valve implant and who cannot or does not want to undergo
the trauma of another open heart surgery. Implanting an expandable
heart valve within an existing target heart valve allows the use of
minimally invasive implantation techniques such as percutaneous of
trans-apical valve implantation techniques.
[0113] The current methods and systems are distinctly different
from Andersen et al. disclosed in U.S. Pat. No. 6,582,462 who
describes the implantation of a valve in a body channel or the
vasculature. Andersen's intent and objective is to describe an
expandable valve that is placed within a body channel or
vasculature and uses the intimate contact created within the
vasculature, body channel, or native valve as support to allow
implantation. In the present invention, an expandable heart valve
prosthesis 100 is implanted within a previously implanted man-made
heart valve prosthesis and uses the intimate contact created with
the previously implanted heart valve prosthesis for support. If the
previously implanted heart valve prosthesis is removed, one will
concurrently remove the expandable heart valve prosthesis 100
located within the previously implanted heart valve prosthesis.
[0114] In one embodiment of the current invention, an expandable
heart valve prosthesis 100 is mounted within a previously implanted
heart valve prosthesis located within a heart. The expandable heart
valve prosthesis 100 may be any valve that can be delivered
minimally invasively, such as percutaneous or trans-apically
delivered valves. In one embodiment of the current invention, the
expandable heart valve prosthesis 100 is a balloon-expandable heart
valve. In another embodiment of the present invention, the
expandable heart valve prosthesis 100 is the 3F Entrata.TM. heart
valve. In another embodiment of the current invention, the
expandable heart valve prosthesis 100 is a self-expandable heart
valve. In yet another embodiment of the present invention, the
expandable heart valve prosthesis 100 is a valve expanded using
some other mechanical or actuating means.
[0115] The previously implanted heart valve prosthesis may be any
valve either native or man-made. In one embodiment of the current
invention, the previously implanted heart valve prosthesis is a
mechanical valve. In another embodiment of the present invention,
the previously implanted heart valve prosthesis is a tissue valve.
The previously implanted heart valve prosthesis may also be made
out of polyurethane or be a tissue-engineered valve. In one
embodiment of the current invention, the previously implanted heart
valve prosthesis can be an expandable heart valve. In yet a further
embodiment of the current invention, more than one expandable heart
valve prosthesis 100 may be implanted within a previously implanted
heart valve prosthesis. As such, multiple minimally invasive heart
valve deliveries may be conducted without removing the existing
valve or existing valves. The previously implanted heart valve
prosthesis may be an aortic valve, mitral valve, pulmonary valve,
or a tricuspid valve. The previously implanted heart valve
prosthesis may also be a a homograft valve or a xenograft valve.
Examples of previously implanted heart valve prosthesis include,
but are not limited to, the Edwards Perimount Valve, the Edwards
BioPhysio Valve, the Medtronic Hancock I Valve, the Medtronic
Hancock M.O. Valve, the Medtronic Hancock II Valve, the Medtronic
Mosaic Valve, the Medtronic Intact Valve, the Medtronic Freestyle
Valve, the St. Jude Toronto Stentless Porcine Valve (SPV), and the
St. Jude Prima Valve.
[0116] The expandable heart valve prosthesis 100 may be made to fit
well within the previously implanted heart valve prosthesis. In one
instance, the posts of the expandable heart valve prosthesis 100
are coordinated to fit the posts of the previously implanted heart
valve prosthesis. Thus in one embodiment of the present invention,
the posts of the expandable heart valve prosthesis 100 matches the
orientation for the posts of the previously implanted heart valve
prosthesis. In one embodiment of the present invention, the
inter-post separation angles of the expandable heart valve
prosthesis 100 add up to 360.degree.. In other embodiments of the
present invention, the inter-post separation angle of the heart
valve prosthesis 100 is 120.degree., 120.degree., and 120.degree.;
or 135.degree., 120.degree., and 105.degree.; or 135.degree.,
105.degree., and 120.degree.; or 120.degree., 135.degree., and
105.degree.; or 120.degree., 105.degree., and 135.degree.; or
105.degree., 135.degree., and 120.degree.; or 105.degree.,
120.degree., and 135.degree..
[0117] FIG. 15 shows an exploded view of FIG. 16 where a heart
valve prosthesis 100 is shown implanted within a previously
implanted heart valve prosthesis 101. In a preferred embodiment,
the inflow ring or annulus 105 of the heart valve prosthesis 100 is
aligned with the inflow ring or annulus 115 of the previously
implanted heart valve prosthesis 101. In another preferred
embodiment, the commissural posts 106 of the heart valve prosthesis
100 is aligned with the commissural posts 116 of the previously
implanted heart valve prosthesis 101.
[0118] It should be noted that although reference is made herein to
a heart valve 100 implanted into a previously implanted heart valve
prosthesis 101 inside the aorta, it is intended for such valve
procedures to encompass any location within the heart 12, and not
to be limited to the aorta.
[0119] In a preferred embodiment of the current invention, the
previously implanted heart valve prosthesis 101 is the same size or
one size larger than the expandable heart valve prosthesis 100. For
purpose of example, if the previously implanted heart valve
prosthesis 101 is 27 mm, the expandable heart valve prosthesis 100
is either 25 mm or 27 mm in size. Thus, in one embodiment of the
current invention, the expandable heart valve prosthesis 100 is the
same size as the previously implanted heart valve prosthesis 101.
In another embodiment of the current invention, the expandable
heart valve prosthesis 100 is larger than the previously implanted
heart valve prosthesis 101. In another embodiment of the current
invention, the expandable heart valve prosthesis 100 is smaller
than the previously implanted heart valve prosthesis 101.
[0120] Clinical records will specify the exact size used during an
earlier implant. The size of the previously implanted heart valve
prosthesis 101 will thus be known. In-vitro tests will show the
best size expandable heart valve prosthesis 100 for a specific size
and type target valve. The optimal size expandable heart valve can
thus be determined from the clinical records from the previous
heart valve implant. Thus in one embodiment of the present
invention, the size of the expandable heart valve prosthesis 100 to
be used is determined from clinical records of prior implants.
[0121] In one embodiment of the current invention, an expandable
stent is implanted within a previously implanted heart valve
prosthesis 101 prior to implanting the expandable heart valve
prosthesis 100. In another embodiment of the current invention,
valvuloplasty is used to expand the orifice of the previously
implanted heart valve prosthesis 101 before implanting an
expandable heart valve prosthesis 100 or before implanting an
expandable stent.
[0122] Any delivery system may be used to deliver the expandable
heart valve prosthesis 100. In one embodiment of the current
invention, the delivery system is a catheter. In another embodiment
of the current invention, the delivery system is a Scapus.TM.. The
expandable heart valve prosthesis 100 may be delivered through any
access point to the heart. In one embodiment of the present
invention, the expandable heart valve prosthesis 100 is delivered
minimally invasively. In one embodiment of the present invention,
the expandable heart valve prosthesis 100 is delivered
percutaneously. In another embodiment of the present invention, the
expandable heart valve prosthesis 100 is delivered
trans-apically.
Sutureless Valve Inserter System and Methods Thereof
[0123] The benefits of a Scapus.TM. valve delivery system may also
be utilized in the case of self-expandable valves. As such, the
delivery system may be used for percutaneous valve delivery,
trans-apical valve delivery, trans-heart delivery. In addition to
these delivery techniques, the Scapus.TM. delivery system may be
utilized in more invasive cardiac procedures such as open heart
procedures.
[0124] The Scapus.TM. delivery system is well suited for delivering
the 3F Enable Aortic Heart Valve.TM. and the other valves described
in co-owned U.S. applications entitled "Minimally Invasive Valve
Replacement System" with the following application Ser. Nos.:
10/680,733; 10/680,719; 10/680,728; 10/680,560; 10/680,716;
10/680,717; 10/680,732; 10/680,562; 10/680,068; 10/680,075;
10/680,069; 10/680,070; 10/680,071; and 10/680,567, all
incorporated herein for reference in their entirety.
Sutureless Valve Inserter System and Methods Thereof
[0125] Current tissue heart valve replacements gradually calcify
after implanted in the heart. Such is also the case when implanting
replacement heart valves in animals such as pigs or sheep. In fact,
replacement heart valves intended for human use typically calcify
faster when implanted in animals such as pigs or sheep. Because of
difference in flow dynamics, physiology, and biochemistry, the best
performing commercially available heart valves will typically show
signs of calcification in pigs and sheep within 10-200 days.
Standard animal models used for pre-clinical valve testing is
frequently sheep, but pigs may also be used. Adolescent sheep have
great propensity to calcify bioprosthetic valves.
[0126] The fact that cardiac valves places in the heart of certain
animal models calcify quickly may be used as basis for creating
calcified animal models for use in the development and testing of
cardiac valves.
[0127] Open heart surgery valve replacement on adolescent sheep
typically results in less than 40% success/survival in the aortic
position, owing to the very small valve sizes and the use of full
bypass. Open heart surgery valve replacement on adolescent sheep
typically results in more than 80% success/survival in the mitral
position owing to the larger valve sizes and the use of beating
heart, partial bypass. Placing replacement valves in the mitral
position during animal testing is not just used to reduce costs but
is also considered a "worst-case" position due to higher
backpressures. Replacement aortic and mitral valves are therefore
frequently placed in the mitral position during animal studies.
[0128] Accordingly, it is one object of the present invention to
provide methods and systems for the creation of a calcified animal
model. Commercially available tissue valves are first implanted in
adolescent sheep. The animals are survived for 10-200 days and the
performance evaluated. Because of the increased propensity for
calcification in animals, all the valves implanted are expected to
be stenotic and/or incompetent due to calcification of tissue
leaflets. Sheep may be evaluated at regular intervals using
echo.
[0129] It is another object of the present invention to utilize the
calcification model described above in the development and testing
of cardiac valves. Using either a percutaneous or trans-apical
implant techniques, place replacement heart valves within the
calcified valves of adolescent sheep. Survive the test animals for
20 weeks (150+/-10 days) or as required by regulatory authorities.
Monitor the replacement valves. Necropsy, pathology, and post
mortem histology may be performed.
[0130] The present invention may be divided into two phases: [0131]
I. Create a calcified animal model by replacing the native valves
of adolescent sheep with commercially available valves and
surviving the animals for 10-200 days. [0132] II. Implant minimally
invasive valves within the calcified valve orifices using a
minimally invasive valve procedure.
[0133] In phase I of the invention, a calcified animal model is
created by replacing the native valves of adolescent sheep with
commercially available valves and surviving the animals. In one
embodiment of the present invention, the heart valve replacement
procedure is an on-pump procedure. In another embodiment of the
present invention, the heart valve replacement procedure is a
minimally invasive heart valve procedure, such as a percutaneous
heart valve replacement procedure, or a trans-apical valve
procedure. In the latter embodiment, the method described herein
would allow testing of a minimally invasive heart valve
repeat-procedure. In one embodiment of the current invention, the
heart valve replacement procedure is conducted endoscopically. In
yet another embodiment of the current invention, the heart valve
replacement procedure is conducted using robots.
[0134] In one embodiment of the present invention, drugs are
utilized to adjust the rate of calcification. In another
embodiment, the valve implanted during Phase I is coated with a
chemical substance used to adjust the rate of calcification.
[0135] Any valve may be implanted during Phase I. In one embodiment
of the present invention, the valve implanted is a tissue valve. In
another embodiment of the present invention, the valve implanted is
a mechanical valve. Implanted heart valves may include aortic
valves, mitral valves, tricuspid valves, or pulmonary valves. A
replacement valve may not necessarily be implanted in its intended
position. As an example, an aortic valve may be implanted in the
mitral position of the animal. Thus in one embodiment of the
present invention, a replacement aortic valve is implanted in the
mitral position. In one embodiment of the current invention,
multiple valves are implanted in different positions at the same
time.
[0136] In a preferred embodiment of the current invention, valves
are implanted in animals whose heart physiology and flow dynamics,
as well as biochemistry, match humans as close as possible. Sheep
and pigs are thus frequently used for heart valve testing. Thus, in
one embodiment of the current invention, sheep is used as the
animal model. In another embodiment of the current invention, pigs
are used as the animal model. Any other primate may be used as an
animal model. In one embodiment of the current invention, animals
of subclass eutheria are used as the animal model. In another
embodiment of the current invention, animals of the suborder
anthropoidea (e.g. monkeys and apes).
[0137] The age of an animal affects the rate of calcification.
Thus, in one embodiment of the current invention, the age of the
animal is the equivalent of adolescence. In another embodiment of
the current invention, the animals used are adults.
[0138] It is one object of the current invention to survive
sufficient animals to the end of Phase II such that pre-clinical
regulatory requirements are met for different regulatory bodies. It
is expected that some animals will not survive the valve
replacements during phase I. Further animals may perish during the
duration of Phase I. Further animals will perish during the
replacement implants during Phase II as well as during the duration
of Phase II. In one preferred embodiment of the present invention,
an excess number of animals are used to start Phase I such that
sufficient numbers of animals are survived all the way through
Phase II. The exact number of animals needed for the start of Phase
I depends on numerous variables including the operator, the type of
animal, the type of procedures.
[0139] It is one object of the current invention to monitor the
progression of calcification and diseases related to implanted
valves. Different monitoring equipment such as ultrasound, MRI, CT,
and cinefluoroscopy, are used during the course of Phase I and
Phase II. In one embodiment of the present invention, echo is used
at 60, 90, and 120 days during Phase I to monitor the implanted
valves.
[0140] In one embodiment of the present invention, the animals in
Phase I are survived for 90-120 days. The length of Phase I depends
on factors such as what type of animal used and what type of tissue
valves used. The valves may be monitored during Phase I. It may be
possible to go to Phase II earlier based upon in-vivo
evaluation.
[0141] In Phase II of the invention, valves are implanted within
the calcified valve orifices. Implant procedures include, but are
not limited to minimally invasive valve procedures, percutaneous
valve procedures, trans-apical valve procedure, on-pump valve
procedure, endoscopic valve procedure, and robotic valve
procedure.
[0142] In one embodiment of the present invention, drugs are
utilized to adjust the rate of calcification. In another
embodiment, the valve implanted during Phase II is coated with a
chemical substance used to adjust the rate of calcification.
[0143] Any valve may be implanted during Phase II. Tissue valves
include, but are not limited to tissue valve, mechanical valves,
aortic valves, mitral valves, tricuspid valves, pulmonary valves. A
replacement valve may not necessarily be implanted in its intended
position. As an example, an aortic valve may be implanted in the
mitral position of the animal. Thus in one embodiment of the
present invention, a replacement aortic valve is implanted in the
mitral position.
[0144] In one embodiment of the present invention, the animals in
Phase I are survived for 20 weeks (150+/-10 days). The length of
Phase II depends on guidelines provided by regulatory bodies.
[0145] In one embodiment of the current invention, the minimally
invasive valve delivery is conducted using a SCAPUS.TM. delivery
system. In one embodiment of the present invention, the valve
utilized is the 3F Therapeutics, Inc. Entrata.TM. valve. In one
embodiment of the present invention, a balloon is used in the
inferior vena cava to regulate pressure during the procedure.
[0146] In one embodiment of the current invention, the replacement
valve in Phase II is seated within the calcified valve orifice of
the valve replacement conducted in Phase I. In another embodiment
of the present invention, the replacement valve in Phase II is
seated just upstream from the calcified valve orifice of the valve
replacement conducted in Phase I. In another embodiment of the
present invention, the replacement valve in Phase II is seated just
downstream from the calcified valve orifice of the valve
replacement conducted in Phase I.
[0147] Obviously, numerous variations and modifications can be made
within departing from the spirit of the present invention.
Therefore, it should be clearly understood that the forms of the
present invention described above and shown in the figures of the
accompanying drawings are illustrative only and are not intended to
limit the scope of the present invention.
* * * * *