U.S. patent application number 10/047581 was filed with the patent office on 2011-11-03 for endovascular aortic valve replacement.
Invention is credited to John H. Stevens.
Application Number | 20110270388 10/047581 |
Document ID | / |
Family ID | 24935849 |
Filed Date | 2011-11-03 |
United States Patent
Application |
20110270388 |
Kind Code |
A9 |
Stevens; John H. |
November 3, 2011 |
Endovascular aortic valve replacement
Abstract
The subject invention relates to a valve replacement system
together with methods of preparation and use, are provided for
endovascular replacement of a heart valve in a host. The valve
replacement system includes up to five components: (1) a prosthetic
valve device, (2) a valve introducer device, (3) an intraluminal
procedure device, (4) a procedure device capsule, and (5) a tissue
cutter. The system provides for endovascular removal of a
malfunctioning valve and subsequent replacement with a permanent
prosthetic heart valve.
Inventors: |
Stevens; John H.; (Palo
Alto, CA) |
Prior
Publication: |
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Document Identifier |
Publication Date |
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US 20020058995 A1 |
May 16, 2002 |
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Family ID: |
24935849 |
Appl. No.: |
10/047581 |
Filed: |
October 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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08615481 |
Mar 15, 1996 |
6338735 |
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10047581 |
Oct 23, 2001 |
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08206419 |
Mar 4, 1994 |
5545214 |
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08615481 |
Mar 15, 1996 |
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07730559 |
Jul 16, 1991 |
5370685 |
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08206419 |
Mar 4, 1994 |
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Current U.S.
Class: |
623/2.11 ;
606/159; 623/2.18 |
Current CPC
Class: |
A61F 2/2427 20130101;
A61M 2210/125 20130101; A61F 2/2433 20130101; A61B 17/32002
20130101; A61M 2025/028 20130101; A61M 25/0125 20130101; A61M
1/3659 20140204; A61M 1/3653 20130101; A61F 2/2436 20130101; A61M
2025/1047 20130101; A61B 2018/00232 20130101; A61B 17/320758
20130101; A61B 2018/00261 20130101; A61M 2025/0078 20130101; A61B
17/320725 20130101; A61M 25/10 20130101; A61F 2220/0016 20130101;
A61M 25/0041 20130101; Y10S 623/904 20130101; A61B 2017/22097
20130101; A61M 2025/1077 20130101 |
Class at
Publication: |
623/002.11 ;
623/002.18; 606/159 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A procedure device capsule for transport of the intraluminal
procedure device to a vascular, cardiac or other intraluminal situs
which when inserted in the lumen of a blood vessel in the presence
of blood flow comprises: one layer comprising a tubular flexible
substrate means having a generally cylindrical outside surface and
a generally cylindrical inside surface characterized as capable of
transporting the intraluminal procedure device to said situs.
2. An intraluminal procedure device for performance of
intravascular or intracardiac or other intraluminal procedures at a
situs which when inserted in the lumen of a host blood vessel in
the presence of blood flow comprises: a layer and a tube, wherein:
i) said layer, the barrier, comprising a durable flexible
selectively permeable umbrella-like conical shaped substrate means
with the conical end perforate and pointing downstream in the host
blood vessel and the distal ends segmented into at least two
segments to allow for differential expansion and contraction of the
segments, characterized as capable of passage through said host
blood vessel to a vascular or cardiac or other intraluminal situs
and of differentially expanding said distal ends to attach to the
walls of and stabilize at said situs, at a determined angle and for
a determined length of time, allowing blood flow through said
permeable substrate means preventing back pressure and
embolization, and providing a working procedure region within the
area confined by the inside of said barrier, and ii) said tube, the
working channel, comprising an elongated tubular durable flexible
substrate means having a generally cylindrical outside surface and
a generally cylindrical inside surface which distal open end is
attached at said situs of the perforation at the conical end of
said barrier and which proximal end extends out the external entry
to said host blood vessel, characterized as allowing external entry
and utilization of instruments at said situs through passage of
said instruments through said working channel, through the
perforate conical end of said barrier and into the procedure
working region.
3. A tissue cutter for removal of undesired tissue within the
vascular or cardiac system or other anatomic lumens which when
inserted into the intraluminal procedure device comprises: at least
one blade and a cable, wherein i) said at least one blade
comprising a collapsible blade, and characterized as capable of
passage through a host blood vessel to a vascular or cardiac situs
while collapsed within a working channel and then entry into the
procedure working region, which when within the procedure working
region comprises: at least one collapsible sharp blade having at
least one hinge mechanism allowing for collapsing and expansion and
attached to zero or more other blades at varying angles to provide
cutting surfaces at various angles, with said collapsible blade
connected to ii) said cable which when within the working channel
comprises: an elongated durable flexible wire which extends to the
exterior of the host through the working channel, said cable
characterized as capable of connection to an outside motor, and of
controlling the speed of rotation of the blade(s).
4. The tissue cutter according to claim 3 wherein the proximal
blade comprises a flexible wire capable of high speed rotation.
5. A valve introducer device for inserting a prosthetic valve
device at a vascular, or cardiac situs which when inserted in the
lumen of a blood vessel in the presence of blood flow comprises: a
layer, a tube, a pusher devise and a bracer, wherein i) said layer,
the introducer capsule, comprising a tubular flexible substrate
means having a generally cylindrical outside surface and a
generally cylindrical inside surface and reinforced at the proximal
end which is open, and having a semi-closed distal end with a
perforate opening having a diameter approximately the same as the
internal diameter of the tube, characterized as capable of
transporting said prosthetic valve device to said situs, ii) said
tube, the introducer channel, comprising an elongated tubular
durable flexible substrate means having a generally cylindrical
outside surface and a generally cylindrical inside surface which
proximal open end is attached at said situs of the distal opening
of said introducer capsule and which distal end extends out the
external entry of said blood vessel, and is characterized as
containing a pusher channel of a pusher device within its lumen,
iii) said pusher device comprising a disc and a tube, said disc of
said pusher device comprising a generally circular disc, with a
generally flat distal surface, a generally flat proximal surface
and a central opening, and made of a durable, flexible material,
having its proximal surface abut said prosthetic valve device
contained within said introducer capsule, and attached at said
central opening of its distal surface is said proximal end of said
tube, which comprises: an elongated flexible cylinder made of
durable, flexible, non-thrombogenic material, having a generally
cylindrical outside surface and a generally cylindrical inside
surface and a smaller internal diameter than that used in said
introducer channel, and is characterized as capable of maintaining
its structural integrity such that it does not distort upon the
application of external pressure, of being contained within the
lumen of said introducer channel with its distal end extending
beyond the vascular entry point via said introducer channel, of
allowing passage of a mounting balloon and guide wire, and of
advancing within the lumen of said introducer channel, upon
application of external pressure to advance said pusher disc, and
thereby said prosthetic valve device within said introducer
capsule, and iv) said bracer, comprising a differentially
expandable device circumferentially attached to the external
surface of said introducer capsule at said capsule's proximal end
and is characterized as having the capability of expanding to hold
said introducer capsule in a precise position during delivery of
said prosthetic valve device.
6. A prosthetic valve device for supplanting or replacing a cardiac
valve which when inserted in the lumen of a blood vessel, in
extra-anatomic conduits or at a cardiac valve annulus situs in the
presence of blood flow comprises: a sleeve, a valve and an annulus,
wherein i) said sleeve comprises a tubular flexible substrate means
having a generally cylindrical outside layer secured to (ii) said
compressible annulus at its base comprising a mounting ring by a
series of mounting pins, and a generally cylindrical inside surface
contacting an inner layer comprising (iii) said valve,
characterized as capable of insertion into a cardiac or vascular
situs through a host blood vessel, host compatible and capable of
autonomous operation, which when inserted in said situs in the
presence of blood flow comprises a flexible annulus having a
generally cylindrical outside surface and a generally cylindrical
inside surface containing at least one cusp to permit blood flow
through said cusp in a single direction; iv) attachment means
comprising at said first and second open ends of said cusp to
permit fixation of said device at least at or above said annulus of
said dysfunctional valve by the mounting ring which comprises; v) a
flexible annulus having a generally cylindrical inside surface and
a generally cylindrical outside surface containing a series of
mounting pins to fixate said prosthetic valve device at said
situs.
7. A valve, characterized as capable of insertion into a cardiac or
vascular situs through a host blood vessel, host compatible and
capable of autonomous operation, which when inserted in said situs
in the presence of blood flow comprises: a flexible annulus having
a generally cylindrical outside surface and a generally cylindrical
inside surface containing at least one cusp to permit blood flow
through said cusp in a single direction.
8. A valve according to claim 7 further comprising attachment means
comprising at said first and second open ends of said cusp to
permit fixation of said device at least at or above said annulus of
said dysfunctional valve by the mounting ring.
9. A mounting ring to fixate an attached device at a situs
characterized as capable of insertion into a cardiac or vascular
situs through a host blood vessel, host compatible and capable of
autonomous operation, which when inserted in said situs in the
presence of blood flow comprises: a flexible annulus having a
generally cylindrical outside surface and a generally cylindrical
inside surface containing a series of mounting pins to fixate said
attached device at the said situs.
10. A valve replacement system for supplanting or replacing a
cardiac valve which when inserted in the lumen of a blood vessel,
in extra-anatomic conduits or at a cardiac valve annulus situs in
the presence of blood flow comprises: a procedure device capsule,
an intraluminal procedure device, a tissue cutter, a valve
introducer device, and a prosthetic valve device.
11. A method for replacing a cardiac or other valve or prosthesis
endovascularly which method comprises: a procedure device capsule
contains and transports a intraluminal procedure device
endovascularly, through surface insertion of and passage through
the host's vasculature, to a valve situs whereby a barrier of said
intraluminal procedure device exits from said procedure device
capsule, expands in a controlled and adjustable manner, abuts the
lumen of the vessel, and encircles the valve situs, and upon which:
a tissue cutter travels through a working channel of said
intraluminal procedure device to said valve situs and upon arrival
at said situs cuts and removes the old valve, prosthesis or other
designated tissue, and any resulting loose matter is trapped by
said barrier or is removed from the host's vasculature through
suction and other tissue retrieval device inserted via said working
channel, and upon removal of said old valve, prosthesis or other
tissue: said barrier is contracted, said intraluminal procedure
device is withdrawn and secured into said procedure device capsule
which is then removed, and a valve introducer device containing a
prosthetic valve device transports said prosthetic valve to said
valve situs via endovascular means, and upon reaching said valve
situs: said valve introducer device's bracer expands to position
said valve introducer device correctly for insertion of said
prosthetic valve device at said valve situs, a pusher device of
said valve introducer device advances to expel said prosthetic
valve device from said introducer capsule, upon which a balloon
which has been introduced by a guide wire via a pusher channel of
said pusher device, is inflated at the situs to securely mount said
prosthetic valve device, and upon secure fixation of said
prosthetic valve device at said situs: said bracer is contracted,
said balloon deflated, and said valve introducer device, said
balloon and said guide wire are removed from said host's
vasculature.
12. A method of supplanting a cardiac or other valve or prosthesis
endovascularly which method comprises: a valve introducer device
containing a prosthetic valve device transports it to a valve
fixation situs endovascularly, through surface insertion of and
passage through the host's vasculature, to the fixation situs and
upon reaching the fixation situs: a valve introducer device's
bracer expands to position said valve introducer device correctly
for insertion of said prosthetic valve device at said valve situs,
a pusher device of said valve introducer device advances to expel a
prosthetic valve device from an introducer capsule, upon which a
balloon which has been introduced by a guide wire via a pusher
channel of said pusher device, is inflated at said situs to
securely mount said prosthetic valve device, and upon secure
fixation of said prosthetic valve device at said situs: said bracer
is contracted, said balloon deflated, and said valve introducer
device, said balloon and said guide wire are removed from said
host's vasculature.
13. A method of use extracting host valves or tissue endovascularly
which method comprises: a procedure device capsule contains and
transports an intraluminal procedure device endovascularly, through
surface insertion of and passage through a host's vasculature, to a
situs for removal whereby a barrier of said intraluminal procedure
device exits from said procedure device capsule, expands in a
controlled and adjustable manner, abuts the lumen of said host
vessel, and encircles said removal situs, and upon which: a tissue
cutter travels through a working channel in said procedure device
to said removal situs and upon arrival at said situs cuts and
removes the old valve, prosthesis or other designated tissue, and
any resulting loose matter is trapped by said barrier or is removed
from said host's vasculature through suction and other tissue
retrieval device inserted via said working channel, and upon
removal of said old valve, prosthesis or other tissue, said barrier
is contracted, said intraluminal procedure device is withdrawn into
and secured in said procedure device capsule, which is then
removed.
14. A method of emboli free endovascular procedures which method
comprises: a procedure device capsule contains and transports an
intraluminal procedure device endovascularly, through surface
insertion of and passage through a host's vasculature, to a situs
for procedure whereby a barrier of said intraluminal procedure
device exits from said procedure device capsule, expands in a
controlled and adjustable manner, abuts the lumen of said vessel,
and encircles said procedure situs, and upon which: a procedure
instrument travels through a working channel in said procedure
device to said procedure situs and upon arrival at said situs
performs its specific task, and any resulting loose matter is
trapped by said barrier or is removed from said host's vasculature
through suction and other tissue retrieval device inserted via said
working channel, and completion of said procedure and removal of
all said procedure instruments through said working channel, said
barrier is contracted, and said intraluminal procedure device is
withdrawn into and secured in said procedure device capsule, which
is then removed.
Description
INTRODUCTION
[0001] 1. Field of the Invention
[0002] This invention relates to devices and methods for
endovascular replacement of a heart valve.
[0003] 2. Background
[0004] It is often necessary to replace malfunctioning heart valves
within the body. Heart valve replacement generally has been
accomplished by a major open heart surgical procedure, requiring
general anesthesia, full cardiopulmonary bypass with complete
cessation of cardiopulmonary activity, seven to ten days of
hospitalization and months of recuperation time. The mortality rate
with this type of procedure is about five to six percent.
[0005] Endovascular procedures for valve replacement provide an
alternative to open heart surgery. For example, in patients with
serious aortic valve disease who are too compromised to tolerate
open heart surgery, surgeons have used endovascular balloon aortic
valvuloplasty. This procedure involves use of endovascular balloon
dilatation to split commissures in diseased aortic valves with
commissural fusion and to crack calcific plaques in calcified
stenotic aortic valves. This method provides only partial and
temporary relief for a patient with a stenotic aortic valve. A
repeat procedure within a year of the first procedure is often
required.
[0006] An alternative treatment regimen is endovascular valve
supplantation. In this procedure, instruments are used to insert a
mechanical valve in the lumen of a central blood vessel via entry
through a distal artery, for example, the brachial or femoral
artery. The descriptive terms distal and proximal, when used in
relation to the vasculature in this application, refer to
directions further and closer from the valve replacement or
procedure site, as applicable. A guide wire is placed through the
entry vessel and fluoroscopically directed to the desired situs.
Flexible catheters are then guided over the guide wires which are
used to propel and direct the new valve through the blood vessel to
the desired central location near to the malfunctioning heart valve
where it supplants the function of the existing valve.
[0007] Endovascular heart procedures, in contrast to open heart
surgical procedures, would require only local anesthesia, partial
or no cardiac bypass, one to two days hospitalization, and should
have a reduced mortality rate as compared to open heart procedures.
However, as discussed in the literature but never actually
practiced, endovascular heart valve supplantation is limited to
supra-annular arterial based mechanical valves which require an
elongated mounting catheter originating at the distal arterial
entry point to maintain the position of the valve in the aorta and
therefore does not provide a permanent or internalized system.
Valve supplantation is also limited to treating regurgitant aortic
valves and is not applicable to stenotic aortic valves or any other
malfunctioning heart valves. In addition, once implanted,
mechanical valves predispose the patient to thrombus formation and
emboli, mandating long term anticoagulant therapy; intracranial
hemorrhages are a serious side effect of long term anticoagulant
therapy.
[0008] A potential alternative to a mechanical valve is a
bioprosthetic valve. A bioprosthetic valve can be either a
homograft (a fresh human), allograft (a fixed human) or a xenograft
(a fixed other species) valve. Homograft valves, in contrast to
xenograft valves, are rarely used because of the lack of access to
fresh human valves. Porcine glutaraldehyde preserved valves are
often used since they are readily accessible and storable and are
available in a variety of sizes. Bioprosthetic valve replacement
does not predispose a patient to thrombus formation or emboli, and,
therefore, requires no long-term anticoagulant therapy.
Bioprosthetic valves are presently a mainstay in aortic valve
replacement. Bioprosthetic heart valve replacement is preferable in
patients who cannot tolerate long-term anticoagulant therapy or are
otherwise potentially noncompliant with a long term medical
regime.
[0009] To date, bioprosthetic and mechanical valves have been
inserted near or at the native annulus site through open heart
surgery and except for the Magovern-Cromie Valve which used pins to
fix the valves have required sutures for fixation at the insertion
site; means for endovascular valve replacement with any valve are
not available. It would therefore be of interest to provide a
endovascular means i) to easily remove a dysfunctional natural or
prosthetic valve and ii) to replace the dysfunctional valve with a
endovascularly replaceable bioprosthetic or flexible synthetic
valve, independently fixed without sutures or catheter, near or at
the native valve annulus site.
Relevant Literature
[0010] U.S. Pat. No. 3,671,979 to Moulopoulos, issued Jun. 27,
1972, describes a endovascularly inserted conical shaped
umbrella-like valve positioned and held in place by an elongated
mounting catheter at a supra-annular site to the aortic valve in a
nearby arterial vessel. The conical end points toward the
malfunctioning aortic valve and the umbrella's distal ends open up
against the aorta wall with reverse blood flow, thereby preventing
regurgitation.
[0011] U.S. Pat. No. 4,056,854 to Boretos, issued Nov. 8, 1977,
describes a endovascularly inserted, catheter mounted,
supra-annular valve in which the circular frame abuts the wall of
the artery and attached flaps of flexible membrane extend distally
in the vasculature. The flaps lie against the artery wall during
forward flow, and close inward towards the central catheter to
prevent regurgitation during reverse blood flow. The Boretos valve
was designed to be positioned against the artery wall during
forward flow, as compared to the mid-center position of the
Moulopoulos valve, to reduce the stagnation of blood flow and
consequent thrombus and embolic formation expected from a valve at
mid-center position.
[0012] Reviews relating to replacement valves include: Gibbon's
Surgery of the Chest, 5th Ed., David C. Sabiston, Jr., M.D., Frank
D. Spencer, M.D., 1990, Vol. II, Ch. 52, pp. 1566-1596, and
Textbook of Interventional Cardiology, Eric J. Topol, 1990, Chs.
43-44, pp. 831-867.
SUMMARY OF THE INVENTION
[0013] According to the subject invention, a valve replacement
system together with methods of preparation and use, are provided
for endovascular replacement of a heart valve in a host. The valve
replacement system includes up to five components: (1) a prosthetic
valve device, (2) a valve introducer device, (3) an intraluminal
procedure device, (4) a procedure device capsule, and (5) a tissue
cutter. The system provides for endovascular removal of a
malfunctioning valve and subsequent replacement with a permanent
prosthetic heart valve.
DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates a procedure device capsule side view.
[0015] FIG. 2 illustrates a side view of an intraluminal procedure
device.
[0016] FIG. 3 illustrates a bottom view of an intraluminal
procedure device.
[0017] FIG. 4 illustrates a top view of an intraluminal procedure
device.
[0018] FIG. 5 illustrates a tissue cutter in a closed position.
[0019] FIG. 6 illustrates a tissue cutter in an open position.
[0020] FIG. 7 illustrates a side view of a valve introducer capsule
with bracer balloons deflated.
[0021] FIG. 8 illustrates a side view of a valve introducer capsule
with bracer balloons inflated.
[0022] FIG. 9 illustrates a side view of a valve introducer capsule
with balloons passed over a guide wire.
[0023] FIG. 10 illustrates a side view of a pusher disc advancing a
valve out of the introducer capsule.
[0024] FIG. 11 illustrates an aortic valve in the side
position.
[0025] FIG. 12 illustrates an aortic valve from the top view.
[0026] FIG. 13 illustrates a side view of an aortic valve with the
mounting ring in the closed position.
[0027] FIG. 14 illustrates a front view of an aortic valve with the
mounting ring in the open position.
[0028] FIG. 15 is a graphic illustration of a side view of a
mounting pin confirmation change with balloon inflation.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0029] The present invention relates to the (supplantation or)
replacement of a cardiac valve in a host through endovascular
means. The valve replacement system includes up to five components:
(1) a prosthetic valve device, (2) an valve introducer device, (3)
an intraluminal procedure device, (4) a procedure device capsule,
and (5) a tissue cutter. All the components of the system are not
required to be used in conjunction with valve replacement; the
description of valve replacement using all the components is merely
exemplary.
[0030] In a general method, the procedure device capsule (FIG. 1),
which contains the intraluminal procedure device, is inserted into
an entry point in the host and used to transport the intraluminal
device to the desired situs, over a guide wire. At the situs, a
selectively permeable barrier of the intraluminal procedure device
exits from the procedure device capsule, expands in a controlled
and adjustable manner and abuts the lumen of the vessel encircling
the old valve or prosthesis (FIGS. 2, 3 & 4). The guide wire is
withdrawn from the working channel of the intraluminal procedure
device leaving the channel available for the passage of the tissue
cutter, angioscope, ultrasound, tissue graspers, and tissue cutting
devices. The channel can also be used for irrigation or applied to
suction apparatus to remove debride, thrombus or other
material.
[0031] The tissue cutter then is inserted into the host through the
working channel of the intraluminal procedure device to the valve
situs where it is used to cut and remove the existing valve from
the situs (FIGS. 5,6). Accurate positioning of the cutter is
assured using transesophageal echocardiography and intra-arterial
or intra-cardiac ultrasound and angioscopy. The precision of the
valve extraction and replacement is important to the success of
endovascular valve replacement. There are several imaging
techniques presently available providing complementary options to
assure this precisions 1) Transesophageal echocardiography can be
continuously used; 2) Intravascular ultrasound passed through the
working channel of the intraluminal procedure device; 3)
Intravascular ultrasound passed intravascularly via the venous
system through the intra-atrial septum across the mitral valve and
into the left ventricle; 4) An angioscope can be passed into the
left ventricle in a like manner which would provide the added
benefit of allowing constant high definition imaging of the entire
procedure and high flow irrigation.
[0032] Any tissue debris resulting from the procedure is trapped by
the barrier of the intraluminal procedure device or is removed from
the host through suction and tissue retrieval devices inserted via
the working channel of the intraluminal procedure device, Tissue
debris is removed via the working channel of the intraluminal
procedure device with suction, grasping devices (e.g. dormier
basket or grasping forceps) or is caught in the barrier of the
intraluminal procedure device to avoid embolism. Once all the
necessary tissue has been removed, contraction of the tissue cutter
allows for removal of the tissue cutter through the working channel
of the intraluminal procedure device. The barrier of the
intraluminal procedure device is contracted and the intraluminal
procedure device is withdrawn into the procedure device capsule
which is then removed.
[0033] The valve introducer device containing the prosthetic valve
device is then inserted and used to transport the replacement valve
to the valve situs, over a guide wire (FIG. 7). The bracer of the
valve introducer device, which optionally can include positioning
balloons surrounding the introducer capsule of the valve introducer
device, inflates in a differential manner, such that certain
balloons inflate more-or less than others, to assure accurate
positioning of the prosthetic valve when delivered out of the
introducer capsule (FIG. 8). A means for pushing the valve out of
the introducer capsule, after the introducer capsule is in the
appropriate position, is to advance the pusher device of the valve
introducer device within the capsule (FIG. 9). A means for securing
the mounting pins into the desired situs is to inflate a balloon
inside of the prosthetic valve device and within the lumen of the
mounting ring (FIGS. 10-15). The capsule positioning balloons and
the intraluminal balloon can then be deflated and the valve
introducer device is withdrawn.
[0034] In order to support the circulation of the patient during
the endovascular aortic valve replacement it will be necessary to
place the patient on partial or complete cardiopulmonary bypass.
There are presently available several means to provide this
support. For example, one method is percutaneous insertion of
venous and arterial cannula with decompression of the left
ventricle by insertion of a pulmonary arterial line allowing
aspiration of blood and marked diminution of left ventricular
filling and ejection.
[0035] The invention provides several advantages, including the
ability to replace or supplant existing cardiac or other valves or
prostheses via a sutureless endovascular means avoiding the
riskier, more expensive and complicated open heart surgical
procedure. This prosthetic valve device, preferably using a
bioprosthesis or other thrombus resistant flexible prosthesis for
the valve leaflets, will avoid the need for permanent anticoagulant
therapy for the host. Once inserted, the valve is capable of
operating autonomously. Further, bioprosthesis replacement valves
in the past have required sutures and, therefore, open heart
surgery for fixation at the annulus or vasculature situs. The
mounting device used with the valve of the subject invention allows
the invention to be fixed via endovascular means without the need
for sutures. The prosthetic valve device is inserted on a permanent
basis, and remains for the life of the valve incorporated in the
device. The life of a bioprosthetic valve, for example, can extend
to over twenty years. Future developments can provide alternative
prosthetic valves with a markedly extended life. Since most of the
patients who are unable to tolerate open heart procedures are
elderly, the bioprosthetic valve will usually outlive the patient.
The intraluminal procedure device and the cutter allow for the
novel ability to perform endovescular procedures without the
serious side effect of causing loose debris and other emboli to
circulate within the vasculature.
[0036] The components of the valve replacement system will now be
described. The procedure device capsule comprises a cylindrical
sleeve made of flexible durable material, for example, teflon
coated polyurethane or other materials which have the following
characteristics: flexible such that it can be maneuvered easily
through vasculature, durable such that it can withstand the
abrasive contact and pressure of instruments inserted and contained
within it, and non-thrombogenic such that blood clots do not
develop and adhere to its surface. The procedure device capsule has
a generally cylindrical outside surface and a generally cylindrical
inside surface with a mesh or grid design. It is characterized as
capable of containing the barrier of the intraluminal procedure
device and other devices which could be used intraluminally, and of
intraluminal transport. The device is introduced over a guide wire
to the said situs (FIG. 1).
[0037] A means for withdrawing the procedure device capsule (15)
partially to allow for full expansion of the intraluminal procedure
device is to have the distal end of the procedure device capsule
and the proximal end of the working channel (5) of the intraluminal
procedure device threaded together by a screw mechanism(10). Upon
rotation of the working channel on the threads of the procedure
device capsule, the intraluminal procedure device can be advanced
within and out of the procedure device capsule. After completion of
work, the intraluminal procedure device can be drawn back into the
procedure device capsule and then secured within the capsule by
rotating the working channel on the threads of the procedure device
capsule in the reverse direction (FIG. 2).
[0038] The intraluminal procedure device functions to aid the
performance of intraluminal procedures via endovascular or other
intraluminal means and comprises a layer (the "barrier") and a tube
(the "working channel"). The barrier (20) comprises an
umbrella-like cone with a generally conical outside surface and a
generally conical inside surface (FIG. 2). Materials for
fabrication of the cone include flexible, durable, and selectively
permeable (such that only certain selected sizes of particles may
pass through it) material, for example, polypropylene, polyester,
dacron or nylon mesh over supports of stainless steel. The apex of
the cone is perforate to allow an exit from the working channel and
points downstream in the vasculature. The barrier is suspended over
the stainless steel tripod (FIG. 3). Attached circumferentially to
the barrier is an expansion device (25, the "Bracer"), such as a
balloon (FIG. 4). The balloon can have four to twenty segments,
each separated by a diaphragm. Each balloon segment has a separate
inflation, deflation channel which allows each segment to have
differential inflation directed from a central external control.
The external device for inflation and/or deflation of each segment
of the Bracer is comprised of means such as syringes or compressed
air cylinders in parallel. Each has a valve in series allowing
inflation when pressure is applied and passive or active deflation
when open. Differential inflation of each balloon segment allows
subtle changes in the angle of the working channel in relation to
the valve situs. Once inflated the barrier is characterized as
capable of allowing blood flow through its permeable surface
preventing back pressure and embolization, and providing a working
procedure region bounded by the inner surface of the barrier and
extending from the barrier's distal ends proximally into the
vasculature and heart (FIG. 2).
[0039] The tube of the intraluminal procedure device, the working
channel, comprises an elongated flexible cylinder. The working
channel is made of durable flexible material, for example, teflon
coated polyurethane or other materials which have the following
characteristics: flexible, durable, and non-thrombogenic. The tube
has a generally cylindrical outside surface and a generally
cylindrical inside surface. The proximal open end of the working
channel is attached around the barrier's perforated conical apex
and its distal end extends out and through the vascular entry
point. For use in an adult human, the working channel preferably
has an internal diameter of about 0.5 to 10 millimeters making it
capable of providing passage for instruments, for example,
ultrasound, angioscopy, debridement, suction, irrigation, retrieval
devices, and the tissue cutter, from outside the host to the
working procedure region. For use in a host other than an adult
human, this internal diameter size range can be varied up or down
depending on the size of the host and lumen. It can also be useful
to have suction or irrigation applied to the working channel.
[0040] The tissue cutter comprises at least one proximal blade and
a cable. The proximal blade (45) comprises a collapsible hinged
(30) blade of length varying from about 1.0 to 20 millimeters with
sharp cutting surfaces. This range of blade length can vary up or
down depending on the size of host and lumen. Alternatively, the
proximal blade can comprise a flexible wire capable of high speed
rotation which would deliver a cutting contact to the tissue. The
blade is made of rigid durable material, for example, stainless
steel or elgiloy. The proximal blade is characterized as capable of
passage through the working channel to the working procedure region
in an unextended state, and then of extension of itself to allow
for cutting of any undesired tissue and finally of return to its
unextended state. Additional blades can be attached to the proximal
blade to increase the cutting ability of the tissue cutter (FIGS.
5,6). For example, two shorter approximately 0.5 to 5.0 millimeter
distal blades (40) can be attached through melding, hinging, or
other connecting methods, to the distal ends of the proximal blade.
This blade length range can vary up or down in size depending on
the size of host and lumen. These blades provide sharp cutting
surfaces at a range from about thirty to one hundred and fifty
degree angles to the proximal blade which allows for simultaneous
cutting at various angles.
[0041] The cable (35) of the tissue cutter comprises a flexible
durable elongated wire and is characterized as being capable of
powering the tissue cutter (FIG. 6). The cable is attached to the
proximal blade at a central or off-center position and connected
distally to an external motor. For example, the cable can be a
steel coaxial cable connected to a DC motor for variable speed
rotation.
[0042] The valve introducer device comprises a layer, a tube, a
pusher device and a bracer. The layer of the valve introducer
device, the introducer capsule, comprises a cylindrical sleeve
having a generally cylindrical outside surface and a generally
cylindrical inside surface reinforced at the proximal end which is
open, and having a semi-closed distal end with a perforate opening,
the distal opening, having a diameter approximately the same as the
internal diameter of the introducer channel (50) (FIG. 7). The
introducer capsule is made of durable, non-thrombogenic, flexible
material, for example, teflon coated polyurethane with a grid or
mesh design. The introducer capsule is characterized as being
capable of containing and maintaining the prosthetic valve device
in its compressed state allowing for easy transport through the
host's vasculature. The introducer capsule is reinforced at its
base with a solid rather than mesh or grid, for example, solid
polyurethane coated with teflon to support the mounting ring and
the mounting pins of the prosthetic valve device in its compressed
state while within the introducer capsule.
[0043] The bracer (70) is circumferentially attached to the
external surface of the introducer capsule at the capsule's
proximal end. The bracer comprises a differentially expandable
device, such as a series of segmented balloons, and is
characterized as having the capability of expanding to hold the
introducer capsule in a precise position during delivery of the
prosthetic valve device (FIG. 8). Each segmented balloon can have
an inflation/deflation channel to provide autonomous segmental
expansion and compression. Differential expansion of the series of
segmented balloons is directed from a central external control as
done with the intraluminal procedure devices. Inflation of each
differentially allows accurate positioning of the introducer
capsule in proximity to the desired site of valve placement.
[0044] The tube of the valve introducer device, the introducer
channel, comprises an elongated flexible cylinder. The introducer
channel (50) is made of durable, flexible material, for example,
teflon coated polyurethane or other materials which have the
following characteristics flexible, durable, and non-thrombogenic.
The introducer channel has a generally cylindrical outside surface
and a generally cylindrical inside surface. The proximal end of the
introducer channel is attached circumferentially around the distal
opening of the introducer capsule and the introducer channel's
distal end exits through the vascular entry point (FIG. 9). For use
in an adult human, the introducer channel preferably has an
internal diameter of about 0.5-10 mm, making it capable of
containing the pusher channel (55) of the pusher device. For use in
a host other than an adult human, this internal diameter size range
can be varied up or down depending on the size of the host and
lumen. The introducer channel and pusher channel are also
characterized as being capable of allowing suction or irrigation
instruments within its lumen.
[0045] The pusher device comprises a disc and a tube. The pusher
disc (60) of the pusher device, the pusher disc, comprises a
generally circular disc, with a generally flat distal surface, a
generally flat proximal surface and a central opening. The diameter
of the opening should be smaller than the diameter used in the
introducer channel. The pusher disc is made of a durable, flexible
material such as teflon coated polyurethane or other materials
which have the following characteristics: flexible and durable. The
proximal surface of the pusher disc abuts the prosthetic valve
device contained within the introducer capsule (FIG. 9).
[0046] Attached at the pusher disc's distal surface
circumuferentially around the central opening of the pusher disc is
the proximal end of the tube, the pusher channel. The pusher
channel, comprises an elongated flexible cylinder and is made of
durable, flexible, non-thrombogenic material, that can maintain its
structural integrity such that it will not distort upon application
of external pressure (e.g. teflon coated polyurethane). The pusher
channel has a generally cylindrical outside surface and a generally
cylindrical inside surface and has a smaller internal diameter than
that used in the introducer channel (FIG. 10). It is characterized
as capable of being contained within the lumen of the introducer
channel with its distal end extending beyond the vascular entry
point via the introducer channel and of allowing passage of the
mounting balloon (75) and guide wire (65). It is also characterized
as being capable of advancing within the lumen of the introducer
channel, upon application of external pressure at the vascular
entry point to advance the pusher disc within the introducer
capsule. The pusher channel is also characterized as being capable
of allowing suction or irrigation instruments within its lumen.
[0047] The prosthetic valve device comprises a sleeve (80), a valve
and an annulus. The sleeve is a flexible cylindrical shaped
cylinder having a generally cylindrical outside surface and a
generally cylindrical inside surface. The sleeve is secured on its
inside surface to the valve and on the base of its outside surface
to a compressible annulus, the mounting ring (85) (FIGS. 11, 12).
Securing means can include suturing, chemical bonding, laser
welding, stapling, or other methods. Securing materials can include
polypropylene, polyester, nylon, stainless steel or other inert,
durable materials. The sleeve is of durable, host compatible,
non-thrombogenic, flexible and compressible material, for example,
dacron or polytetrafluorethylene, to allow it to be easily
compressed, maneuvered and transported through the vasculature to
permit endovascular placement. The sleeve's durability permits
secure attachment to other objects and layers, and allows the
sleeve to remain intact despite the replacement procedure, and the
long term of the prosthetic device within the host. All components
of the prosthetic valve device, the mounting ring, sleeve and
valve, are flexible, compressible, non-thrombogenic and
durable.
[0048] Secured to the inner layer of the prosthetic valve device
comprises a valve which functions to permit unidirectional
circulatory flow of blood. The valve comprises a cylindrical shaped
annulus (100) having a generally cylindrical outside surface and a
generally cylindrical inside surface containing at least one cusp
(95) to permit blood flow in a single direction. The cusp(s) are
attached at the distal end (relative to blood flow) of the
cylindrical annulus. The cusp(s) open distally to permit the
circulation's flow of blood through the valve situs, and then
alternately close centrally to prevent circulation back-flow. The
valve is flexible, compressible, host-compatible, and
non-thrombogenic. The valve can be, for example, a glutaraldehyde
fixed porcine aortic valve which has three cusps that open distally
to permit unidirectional blood flow. The valve can also be fresh,
cryopreserved or glutaraldehyde fixed allografts or xenografts. The
optimal material will be synthetic such that it is manufactured
from non-biological materials, non-thrombogenic, flexible such that
it can be transported through the vasculature, biocompatible and
very durable such that it can withstand a permanent fixation at the
valve site. It is highly desirable to use flexible material where
the valve is to be inserted via endovascular means.
[0049] The mounting ring (85) of the prosthetic valve device is
preferably attached at the base of the outside surface of the
sleeve. The mounting ring is made of materials that are durable,
have been high tensile strength, excellent fatigue characteristics
and corrosion resistant (for example, stainless steel, MP35N or
elgiloy) and is structured in a compressible architecture such that
it can contract upon application and expand upon release of
external pressure and still maintain its basic formation. The
mounting ring has a generally cylindrical outside surface and a
generally cylindrical inside surface comprised of a series of
mounting pins (90) to fix the prosthetic valve device at the
designated valve situs (FIGS. 13-15). The mounting ring provides
endovascular sutureless fixation of the device allowing it to
operate autonomously. The pins are secured by melding, welding or
other connecting methods, at about 30 to about 150 degree angles to
the mounting ring. The composite of angles provides for secure
fixation such that the-prosthetic valve device can tolerate the
degree and directional pressure variations on the valve occurring
during the different phases of the cardiac cycle. As uniform
pressure is exerted at the inner surface of the mounting ring, as
for example by inflation of the mounting balloon, the mounting ring
expands and the pins extend into and secure to the lumen wall.
[0050] Once the endovascular implantation of the prosthetic valve
device is completed in the host, the function of the prosthetic
valve device can be monitored by the same methods as used to
monitor valve replacements done by open heart surgery. Routine
physical examination, periodic echocardiography or angiography can
be performed. In contrast to open heart surgery, however, the host
requires a short recovery period and can return home within one day
of the endovascular procedure. The prosthetic valve device can be
used in any patient where bioprosthetic valves are indicated,
namely elderly patients with cardiac valve diseases, and patients
unable to tolerate open heart procedures or life-long
anticoagulation. In addition, with the development of longer-life,
flexible, non-thrombogenic synthetic valve alternatives to
bioprosthesis', the prosthetic valve device will be indicated in
all patients where the relative advantages of the life-span, the
non-thrombogenic quality, and the ease of insertion of prosthetic
valve devices outweigh the disadvantages of mechanical valves.
Anticoagulation may be beneficial in certain clinical situations
for either short or long term use.
[0051] The intraluminal procedure device, the procedure device
capsule and the tissue cutter can be independently applied, or
applied in conjunction with each other, to instrumentation at or
removal of cardiac, aortic, cerebrovascular, mesenteric, renal, or
peripheral vessel valves or tissue, and would be especially
important anywhere in the cardiac or vascular system where
peripheral embolization-is problematic or accurate positioning of
instruments is essential. They can also be used in other body
lumens, for example, the gastrointestinal, genitourinary, biliary,
and respiratory tracts. In addition, the valve replacement system
can be used to supplant as well as replace a host's valve or
prosthesis. In that procedure the dysfunctional valve or prosthesis
is not removed by the tissue cutter, and the prosthetic valve
device is fixated at a vascular situs such that the device
supplants the function of the dysfunctional valve or prosthesis,
Also, the valve replacement system could be used in non-human
species, for example, other mammals.
[0052] All publications and patent applications are herein
incorporated by reference to the same extent as if each individual
publication or patent application was specifically and individually
indicated to be incorporated by reference.
[0053] The invention now being fully described, it will be apparent
to one of ordinary skill in the art that many changes and
modifications can be made thereto without departing from the spirit
or scope of the appended claims.
* * * * *