U.S. patent application number 11/692889 was filed with the patent office on 2008-01-03 for implantable prosthetic valve.
Invention is credited to Assaf Bash, Netanel Benlchou, Benjamin Spenser, Avraham Zakai.
Application Number | 20080004688 11/692889 |
Document ID | / |
Family ID | 25523346 |
Filed Date | 2008-01-03 |
United States Patent
Application |
20080004688 |
Kind Code |
A1 |
Spenser; Benjamin ; et
al. |
January 3, 2008 |
IMPLANTABLE PROSTHETIC VALVE
Abstract
A valve prosthesis device is disclosed suitable for implantation
in body ducts. The device comprises a support stent, comprised of a
deployable construction adapted to be initially crimped in a narrow
configuration suitable for catheterization through the body duct to
a target location and adapted to be deployed by exerting
substantially radial forces from within by means of a deployment
device to a deployed state in the target location, and a valve
assembly comprising a flexible conduit having an inlet end and an
outlet, made of pliant material attached to the support beams
providing collapsible slack portions of the conduit at the outlet.
The support stent is provided with a plurality of longitudinally
rigid support beams of fixed length. When flow is allowed to pass
through the valve prosthesis device from the inlet to the outlet,
the valve assembly is kept in an open position, whereas a reverse
flow is prevented as the collapsible slack portions of the valve
assembly collapse inwardly providing blockage to the reverse
flow.
Inventors: |
Spenser; Benjamin;
(Caesarea, IL) ; Benlchou; Netanel; (Nir Etzion,
IL) ; Bash; Assaf; (Givat Ada, IL) ; Zakai;
Avraham; (Zichron Yaacov, IL) |
Correspondence
Address: |
EDWARDS LIFESCIENCES CORPORATION
LEGAL DEPARTMENT
ONE EDWARDS WAY
IRVINE
CA
92614
US
|
Family ID: |
25523346 |
Appl. No.: |
11/692889 |
Filed: |
March 28, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10637882 |
Aug 8, 2003 |
|
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|
11692889 |
Mar 28, 2007 |
|
|
|
10270252 |
Oct 11, 2002 |
6730118 |
|
|
10637882 |
Aug 8, 2003 |
|
|
|
09975750 |
Oct 11, 2001 |
6893460 |
|
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10270252 |
Oct 11, 2002 |
|
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Current U.S.
Class: |
623/1.13 ;
623/1.24; 623/2.14; 623/2.15 |
Current CPC
Class: |
A61F 2220/0083 20130101;
A61F 2230/0054 20130101; A61F 2/2436 20130101; A61F 2/82 20130101;
A61F 2/2409 20130101; A61F 2/2463 20130101; A61F 2250/0098
20130101; A61F 2/2427 20130101; A61F 2/2421 20130101; A61F
2220/0008 20130101; A61F 2/2403 20130101; A61F 2220/0075 20130101;
A61F 2210/0014 20130101; A61F 2/2412 20130101; A61F 2/9522
20200501; A61F 2230/0069 20130101; A61F 2220/0016 20130101; A61F
2/2415 20130101; A61F 2/2418 20130101; A61F 2/9524 20200501; A61F
2/2433 20130101; A61F 2250/001 20130101 |
Class at
Publication: |
623/001.13 ;
623/001.24; 623/002.14; 623/002.15 |
International
Class: |
A61F 2/06 20060101
A61F002/06; A61F 2/24 20060101 A61F002/24 |
Claims
1-49. (canceled)
50. A prosthetic valve assembly for use in replacing a deficient
native valve, the valve assembly comprising: a valve having a
plurality of leaflets, a base, and a plurality of commissure
points; a valve support comprising a generally cylindrical band
comprising a plurality of expandable cells, the valve support
configured to be collapsible for transluminal delivery and
expandable to contact the anatomical annulus of the native valve
when the assembly is positioned in situ, said generally cylindrical
band of the valve support supporting the base and the commissure
points of the valve.
51. The valve assembly of claim 50, wherein one or more of the
commissure points of the valve are positioned and secured at or
adjacent one of the expandable cells.
52. The valve assembly of claim 50, further comprising: an anchor
for engaging the lumen wall when expanded in place for preventing
substantial migration of the valve assembly after deployment;
wherein the anchor is itself configured to be expandable, and
wherein at least part of the anchor is positioned away from the
generally cylindrical band of the valve support.
53. (canceled)
54. The valve assembly of claim 52, wherein the anchor has an
expanded diameter that is different from the expanded diameter of
the valve support.
55. (canceled)
56. The valve assembly of claim 50, further comprising: an anchor
for engaging the lumen wall when expanded in place for preventing
substantial migration of the valve assembly after deployment:
wherein the anchor comprises one or more hooks extending radially
outward from the valve support.
57. The valve assembly of claim 56, wherein the valve support
comprises nickel titanium.
58. A method of replacing a deficient native valve comprising the
steps of: providing a prosthetic valve assembly, the assembly
comprising a valve, a valve support comprising a plurality of
expandable cells and having the base and the commissures of the
valve positioned and secured at or adjacent the expandable cells;
collapsing the valve support and anchor to fit on a distal portion
of a catheter; advancing the catheter to the deficient native valve
to a position within adjacent the leaflets and within the annulus
of the deficient native valve; deploying the valve assembly within
the deficient native valve, whereby the valve support expands
against the leaflets of the deficieint native valve; and
withdrawing the catheter, leaving the valve assembly to function in
place of the deficient native valve.
59. The method of claim 58, further comprising the step of
positioning the valve support and anchor within a generally tubular
sheath extending around the distal portion of the catheter.
60. The method of claim 58, wherein the anchor is
self-expanding.
61. The method of claim 58, wherein the valve support is
self-expanding.
62. The method of claim 58, wherein the valve support is
balloon-expandable.
63. The method of claim 58, further comprising the step of securing
a portion of the valve support to the catheter.
64. The method of claim 58, wherein deploying the valve assembly
comprises the step of crushing the native valve leaflets against
the native valve annulus.
65. (canceled)
66. The method of claim 67, wherein the anchor is spaced from the
valve support.
67. The method of claim 58, wherein the prosthetic valve assembly
further comprises an anchor for engaging a lumen wall for
preventing substantial migration of the valve assembly when
positioned in place.
68. A prosthetic valve assembly for use in replacing a deficient
native valve, the valve assembly comprising: a valve having a
plurality of leaflets and commissure points; a valve support
comprising a plurality of expandable cells and a plurality of
longitudinal bars, the valve support configured to be collapsible
for transluminal delivery and expandable to contact the anatomical
annulus of the native valve when the assembly is positioned in
situ, said valve support supporting the base and the commissure
points of the valve, wherein the commissure points of the valve are
secured to the valve support at the longitudinal bars and adjacent
one or more of the expandable cells.
69. The valve assembly of claim 68, wherein the valve support is
self-expanding.
70. The valve assembly of claim 68, wherein the valve support is
balloon expandable.
71. The valve assembly of claim 68, wherein the valve support is
configured to press radially against the native valve leaflets to
hold the native valve leaflets against walls of the native valve
annulus and/or against walls of an adjacent lumen to thereby
prevent the native valve leaflets from obstructing the native valve
annulus.
72. The valve assembly of claim 68, wherein the longitudinal bars
of the valve support further comprise a plurality of holes, wherein
the plurality of leaflets are secured to the longitudinal bars via
suture lines passing through the plurality of holes.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 10/637,882, filed Aug. 8, 2003, which is a
divisional of co-pending U.S. patent application Ser. No.
10/270,252, filed Oct. 11, 2002, which is in turn a
continuation-in-part of co-pending U.S. patent application Ser. No.
09/975,750, filed Oct. 11, 2001, all of which are incorporated
herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to implantable devices. More
particularly, it relates to a valve prosthesis for cardiac
implantation or for implantation in other body ducts.
BACKGROUND OF THE INVENTION
[0003] There are several known prosthetic valves that have been
previously described. U.S. Pat. No. 5,411,552 (Andersen et al.),
entitled VALVE PROSTHESIS FOR IMPLANTATION IN THE BODY AND CATHETER
FOR IMPLANTING SUCH VALVE PROSTHESIS, discloses a valve prosthesis
comprising a stent made from an expandable cylinder-shaped thread
structure comprising several spaced apices. The elastically
collapsible valve is mounted on the stent with the commissural
points of the valve secured to the projecting apices, which
prevents the valve from turning inside out. Deployment of the valve
can be achieved by using an inflatable balloon which in its
deflated state is used to carry about it the valve structure to its
position and, when inflated, deploys the stent in position to its
final size. See, also, U.S. Pat. No. 6,168,614 (Andersen et al.)
entitled VALVE PROSTHESIS FOR IMPLANTATION IN THE BODY and U.S.
Pat. No. 5,840,081 (Andersen et al.), entitled SYSTEM AND METHOD
FOR IMPLANTING CARDIAC VALVES.
[0004] In PCT/EP97/07337 (Letac, Cribier et al.), published as WO
98/29057, entitled VALVE PROSTHESIS FOR IMPLANTATION IN BODY
CHANNELS, there is disclosed a valve prosthesis comprising a
collapsible valve structure and an expandable frame on which the
valve structure is mounted. The valve structure is composed of a
valvular tissue compatible with the human body and blood, the
valvular tissue being sufficiently supple and resistant to allow
the valve structure to be deformed from a closed state to an opened
state. The valvular tissue forms a continuous surface and is
provided with guiding means formed or incorporated within, the
guiding means creating stiffened zones which induce the valve
structure to follow a patterned movement in its expansion to its
opened state and in its turning back to its closed state. The valve
structure can be extended to an internal cover which is fastened to
the lower part of the valve structure to prevent regurgitation.
[0005] There are several known methods currently used for replacing
aortic valves and several types of artificial prosthetic devices.
Mechanical valves are commonly used in several different designs
(single and double flap) manufactured by well-known companies such
as St. Jude, Medtronic, Sulzer, and others. Some of the main
disadvantages of these devices are: a need for permanent treatment
of anticoagulants, noisy operation, and a need for a large-scale
operation to implant.
[0006] There is a wide range of biologically based valves made of
natural valves or composed of biological materials such as
pericardial tissue. These too are made and marketed by well-known
companies such as Edwards Lifesciences, Medtronic, Sulzer, Sorin,
and others.
[0007] Polymer valves are new and are not yet in use, but several
companies are in the process of developing such products. A new
type of prosthesis is being considered, based on artificial polymer
materials such as polyurethane.
[0008] The present invention introduces several novel structural
designs for implantable valves. An aspect of the present invention
deals with the possibility of implanting the valve percutaneously,
i.e., inserting the valve assembly on a delivery device similar to
a catheter, then implanting the valve at the desired location via a
large blood vessel such as the femoral artery, in a procedure
similar to other known interventional cardiovascular procedures.
The percutaneous deployment procedure and device has an impact on
the product design in several parameters, some of which are
explained hereinafter.
[0009] The percutaneous implantation of medical devices and
particularly prosthetic valves is a preferred surgical procedure
for it involves making a very small perforation in the patient's
skin (usually in the groin or armpit area) under local anesthetic
and sedation, as opposed to a large chest surgery incision, which
requires general anesthesia, opening a large portion of the chest,
and cardiopulmonary bypass. This percutaneous procedure is
therefore considered safer.
[0010] The present invention provides a series of new concepts in
the field of aortic valves and other human valves.
SUMMARY OF THE INVENTION
[0011] It is therefore thus provided, in accordance with a
preferred embodiment of the present invention, a valve prosthesis
device suitable for implantation in body ducts, the device
comprising:
[0012] a support stent, comprised of a deployable construction
adapted to be initially crimped in a narrow configuration suitable
for catheterization through the body duct to a target location and
adapted to be deployed by exerting substantially radial forces from
within by means of a deployment device to a deployed state in the
target location, the support stent provided with a plurality of
longitudinally rigid support beams of fixed length; and
[0013] a valve assembly comprising a flexible conduit having an
inlet end and an outlet, made of pliant material attached to the
support beams providing collapsible slack portions of the conduit
at the outlet,
[0014] whereby when flow is allowed to pass through the valve
prosthesis device from the inlet to the outlet the valve assembly
is kept in an open position, whereas a reverse flow is prevented as
the collapsible slack portions of the valve assembly collapse
inwardly providing blockage to the reverse flow.
[0015] Furthermore, in accordance with another preferred embodiment
of the present invention, the support stent comprises an annular
frame.
[0016] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly has a tricuspid
configuration.
[0017] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly is made from
biocompatible material
[0018] Furthermore, in accordance with another preferred embodiment
of the present invention, the valve assembly is made from
pericardial tissue, or other biological tissue.
[0019] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly is made from
biocompatible polymers.
[0020] Furthermore, in accordance with another preferred embodiment
of the present invention, the valve assembly is made from materials
selected from the group consisting of polyurethane and polyethylene
terephthalate (PET).
[0021] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly comprises a main body
made from PET (polyethylene terephthalate) and leaflets made from
polyurethane.
[0022] Furthermore, in accordance with another preferred embodiment
of the present invention, said support stent is made from nickel
titanium.
[0023] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams are substantially
equidistant and substantially parallel so as to provide anchorage
for the valve assembly.
[0024] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams are provided with bores
so as to allow stitching or tying of the valve assembly to the
beams.
[0025] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams are chemically adhered
to the support stent.
[0026] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly is riveted to the
support beams.
[0027] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly is stitched to the
support beams.
[0028] Furthermore, in accordance with another preferred embodiment
of the present invention, said beams are manufactured by injection
using a mold, or by machining.
[0029] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly is rolled over the
support stent at the inlet.
[0030] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve device is manufactured using
forging or dipping techniques.
[0031] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly leaflets are longer
than needed to exactly close the outlet, thus when they are in the
collapsed state substantial portions of the leaflets fall on each
other creating better sealing.
[0032] Furthermore, in accordance with another preferred embodiment
of the present invention, said valve assembly is made from coils of
a polymer, coated by a coating layer of same polymer.
[0033] Furthermore, in accordance with another preferred embodiment
of the present invention, said polymer is polyurethane.
[0034] Furthermore, in accordance with another preferred embodiment
of the present invention, the support stent is provided with heavy
metal markers so as to enable tracking and determining the valve
device position and orientation.
[0035] Furthermore, in accordance with another preferred embodiment
of the present invention, the heavy metal markers are selected from
gold, platinum, iridium, or tantalum.
[0036] Furthermore, in accordance with another preferred embodiment
of the present invention, the valve assembly leaflets are provided
with radio-opaque material at the outlet, so as to help tracking
the valve device operation in vivo.
[0037] Furthermore, in accordance with another preferred embodiment
of the present invention, said radio-opaque material comprises gold
thread.
[0038] Furthermore, in accordance with another preferred embodiment
of the present invention, the diameter of said support stent, when
fully deployed is in the range of from about 19 to about 25 mm.
[0039] Furthermore, in accordance with another preferred embodiment
of the present invention, the diameter of said support stent may be
expanded from about 4 to about 25 mm.
[0040] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams are provided with bores
and wherein the valve assembly is attached to the support beams by
means of U-shaped rigid members that are fastened to the valve
assembly and that are provided with extruding portions that fit
into matching bores on the support beams.
[0041] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams comprise rigid support
beams in the form of frame construction, and the valve assembly
pliant material is inserted through a gap in the frame and a
fastening rod is inserted through a pocket formed between the
pliant material and the frame and holds the valve in position.
[0042] Furthermore, in accordance with another preferred embodiment
of the present invention, the main body of the valve assembly is
made from coiled wire coated with coating material.
[0043] Furthermore, in accordance with another preferred embodiment
of the present invention, the coiled wire and the coating material
is made from polyurethane.
[0044] Furthermore, in accordance with another preferred embodiment
of the present invention, a strengthening wire is interlaced in the
valve assembly at the outlet of the conduit so as to define a fault
line about which the collapsible slack portion of the valve
assembly may flap.
[0045] Furthermore, in accordance with another preferred embodiment
of the present invention, the strengthening wire is made from
nickel titanium alloy.
[0046] Furthermore, in accordance with another preferred embodiment
of the present invention, there is provided a valve prosthesis
device suitable for implantation in body ducts, the device
comprising a main conduit body having an inlet and an outlet and
pliant leaflets attached at the outlet so that when a flow passes
through the conduit from the inlet to the outlet the leaflets are
in an open position allowing the flow to exit the outlet, and when
the flow is reversed the leaflets collapse so as to block the
outlet, wherein the main body is made from PET and collapsible
leaflets are made form polyurethane.
[0047] Furthermore, in accordance with another preferred embodiment
of the present invention, support beams made from polyurethane are
provided on the main body and wherein the leaflets are attached to
the main body at the support beams.
[0048] Furthermore, in accordance with another preferred embodiment
of the present invention, said support beams are chemically adhered
to the main body.
[0049] Furthermore, in accordance with another preferred embodiment
of the present invention, there is provided a valve prosthesis
device suitable for implantation in body ducts, the device
comprising:
[0050] a support stent, comprised of a deployable construction
adapted to be initially crimped in a narrow configuration suitable
for catheterization through the body duct to a target location and
adapted to be deployed by exerting substantially radial forces from
within by means of a deployment device to a deployed state in the
target location, the support stent provided with a plurality of
longitudinally rigid support beams of fixed length;
[0051] a valve assembly comprising a flexible conduit having an
inlet end and an outlet, made of pliant material attached to the
support beams providing collapsible slack portions of the conduit
at the outlet; and
[0052] substantially equidistant rigid support beams interlaced or
attached to the slack portion of the valve assembly material,
arranged longitudinally.
[0053] Furthermore, in accordance with another preferred embodiment
of the present invention, there is provided a crimping device for
crimping the valve device described above or in Claim 1, the
crimping device comprising a plurality of adjustable plates that
resemble a typical SLR (Single Lens Reflex) camera variable
restrictor, each provided with a blade, that are equally dispersed
in a radial symmetry but each plate moves along a line passing off
an opening in the center, all plates equidistant from that center
opening.
[0054] Furthermore, in accordance with another preferred embodiment
of the present invention, the multiple plates are adapted to move
simultaneously by means of a lever and transmission.
[0055] Furthermore, in accordance with another preferred embodiment
of the present invention, there is provided a method for deploying
an implantable prosthetic valve device from the retrograde approach
(approaching the aortic valve from the descending aorta) or from
the antegrade approach (approaching the aortic valve from the left
ventricle after performing a trans-septal puncture) at the natural
aortic valve position at the entrance to the left ventricle of a
myocardium of a patient, the method comprising the steps of:
[0056] (a) providing a balloon catheter having a proximal end and a
distal end, having a first and second independently inflatable
portions, the first inflatable portion located at the distal end of
the catheter and the second inflatable portion adjacently behind
the first inflatable portion;
[0057] (b) providing a guiding tool for guiding the balloon
catheter in the vasculature of the patient;
[0058] (c) providing a deployable implantable valve prosthesis
device adapted to be mounted on the second inflatable portion of
the balloon catheter;
[0059] (d) for the retrograde approach, guiding the balloon
catheter through the patient's aorta using the guiding tool, the
valve device mounted over the second inflatable portion of the
balloon catheter until the first inflatable portion of the balloon
catheter is inserted into the left ventricle, whereas the second
inflatable portion of the balloon catheter is positioned at the
natural aortic valve position;
[0060] (e) for the antegrade approach, guiding the balloon catheter
through the patient's greater veins, right atrium, left atrium, and
left ventricle using the guiding tool, the valve device mounted
over the second inflatable portion of the balloon catheter until
the first inflatable portion of the balloon catheter is inserted
into the left ventricle, whereas the second inflatable portion of
the balloon catheter is positioned at the natural aortic valve
position;
[0061] (f) inflating the first inflatable portion of the balloon
catheter so as to substantially block blood flow through the
natural aortic valve and anchor the distal end of the balloon
catheter in position;
[0062] (g) inflating the second inflatable portion of the balloon
catheter so as to deploy the implantable prosthetic valve device in
position at the natural aortic valve position;
[0063] (h) deflating the first and second inflatable portions of
the balloon catheter; and
[0064] (i) retracting the balloon catheter and removing it from the
patient's body.
[0065] Furthermore, in accordance with another preferred embodiment
of the present invention, the guiding tool comprises a guide
wire.
[0066] Furthermore, in accordance with another preferred embodiment
of the present invention, there is provided a method for deploying
an implantable prosthetic valve device at the natural aortic valve
position at the entrance to the left ventricle of a myocardium of a
patient, the method comprising the steps of:
[0067] (a) providing a balloon catheter having a proximal end and a
distal end, having a first and second independently inflatable
portions, the first inflatable portion located at the distal end of
the catheter and the second inflatable portion adjacently behind
the first inflatable portion;
[0068] (b) providing a guiding tool for guiding the balloon
catheter in the vasculature of the patient;
[0069] (c) providing a deployable implantable valve prosthesis
device adapted to be mounted on the first inflatable portion of the
balloon catheter, and a deployable annular stent device adapted to
be mounted over the second inflatable portion of the balloon
catheter, the deployable implantable valve prosthesis device and
the deployable annular stent kept at a predetermined distant
apart;
[0070] (d) guiding the balloon catheter through the patient's aorta
using the guiding tool, the valve device mounted over the first
inflatable portion of the balloon catheter and the deployable
annular stent mounted over the second inflatable portion of the
balloon catheter, until the first inflatable portion of the balloon
catheter is positioned at the natural aortic valve position;
[0071] (e) inflating the second inflatable portion of the balloon
catheter so that the deployable stent device is deployed within the
aorta thus anchoring the deployable annular stent and the coupled
valve device in position;
[0072] (f) inflating the first inflatable portion of the balloon
catheter so as to deploy the implantable prosthetic valve device in
position at the natural aortic valve position;
[0073] (g) deflating the first and second inflatable portions of
the balloon catheter; and
[0074] (h) retracting the balloon catheter and removing it from the
patient's body.
[0075] Furthermore, in accordance with another preferred embodiment
of the present invention, a valve prosthesis device suitable for
implantation in body ducts comprises:
[0076] an expandable support frame the support frame provided with
a plurality of longitudinally rigid support beams of fixed length;
and
[0077] a valve assembly comprising a flexible conduit having an
inlet end and an outlet, made of pliant material attached to the
support beams providing collapsible slack portions of the conduit
at the outlet,
[0078] whereby when flow is allowed to pass through the valve
prosthesis device from the inlet to the outlet the valve assembly
is kept in an open position, whereas a reverse flow is prevented as
the collapsible slack portions of the valve assembly collapse
inwardly providing blockage to the reverse flow.
[0079] Furthermore, in accordance with another preferred embodiment
of the present invention, the support frame comprises a deployable
construction adapted to be initially crimped in a narrow
configuration suitable for catheterization through the body duct to
a target location and adapted to be deployed by exerting
substantially radial forces from within by means of a deployment
device to a deployed state in the target location.
[0080] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams have a U-shaped cross
section.
[0081] Furthermore, in accordance with another preferred embodiment
of the present invention, a holder is used to secure the plaint
material to the support beams.
[0082] Furthermore, in accordance with another preferred embodiment
of the present invention, the support frame comprises three
segments that form a circular assembly when assembled.
[0083] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams point inwardly with
respect to a central longitudinal axis of the device.
[0084] Furthermore, in accordance with another preferred embodiment
of the present invention, the device is further provided with a
restricting tapered housing, for housing it in a crimped state.
[0085] Furthermore, in accordance with another preferred embodiment
of the present invention, hooks are provided to secure the device
in position after it is deployed.
[0086] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams comprise longitudinal
bars having a narrow slit used as the commissural attachment so
that extensions the pliant material are tightly inserted through
it.
[0087] Furthermore, in accordance with another preferred embodiment
of the present invention, the extensions of the pliant material are
wrapped about rigid bars serving as anchorage means.
[0088] Furthermore, in accordance with another preferred embodiment
of the present invention, extensions of the pliant material are
sutured to each other at the rigid bars.
[0089] Furthermore, in accordance with another preferred embodiment
of the present invention, a bottom portion of the pliant material
is attached to the inlet.
[0090] Furthermore, in accordance with another preferred embodiment
of the present invention, the support beams are each provided with
a rounded pole, forming a loop through which the pliant material is
inserted.
[0091] Furthermore, in accordance with another preferred embodiment
of the present invention, the pliant material is provided with
longitudinal bars attached to the pliant material at positions
assigned for attachment to the support frame, in order to prevent
localized stress from forming.
[0092] Furthermore, in accordance with another preferred embodiment
of the present invention, the device is further provided with
longitudinal bars having protrusions that are inserted in bores in
the pliant material, a sheet of PET and through bores provided on
the support beams.
[0093] Furthermore, in accordance with another preferred embodiment
of the present invention, pliant material is sutured leaving the
slack portions free of sutures.
[0094] Furthermore, in accordance with another preferred embodiment
of the present invention, a connecting member with a split portion
is used to connect leaflets of the pliant material to the support
beams, the split connecting member compressing the pliant material
in position.
[0095] Furthermore, in accordance with another preferred embodiment
of the present invention, a portion of the connecting member is
perpendicular to the split portion.
[0096] Furthermore, in accordance with another preferred embodiment
of the present invention, the support frame is provided with
metallic members coupled to the stent and rigid members are
positioned on two opposite sides of the metallic member and held
against each other holding portion of the pliant material between
them, sutured, the metallic members wrapped with PET.
[0097] Furthermore, in accordance with another preferred embodiment
of the present invention, the device is further provided with
spring in order to reduce wear of the pliant material.
[0098] Furthermore, in accordance with another preferred embodiment
of the present invention, the spring is provided with a spiral.
[0099] Furthermore, in accordance with another preferred embodiment
of the present invention, the spring is made from stainless
steel.
[0100] Furthermore, in accordance with another preferred embodiment
of the present invention, the spring is attached to slots provided
on the support frames.
[0101] Furthermore, in accordance with another preferred embodiment
of the present invention, the pliant material is sutured to the
support frame forming pockets.
[0102] Furthermore, in accordance with another preferred embodiment
of the present invention, attachment bars are provided on the stent
support at a portion of the stent close to the outlet, onto which
the pliant material is coupled, and wherein the pliant material is
attached circumferentially to the inlet, leaving slack pliant
material.
[0103] Furthermore, in accordance with another preferred embodiment
of the present invention, the outlet is tapered with respect to the
inlet.
[0104] Furthermore, in accordance with another preferred embodiment
of the present invention, the support frame at the outlet is wider
in diameter than the pliant material forming the outlet.
[0105] Furthermore, in accordance with another preferred embodiment
of the present invention, the pliant material is reinforced using
PET.
[0106] Furthermore, in accordance with another preferred embodiment
of the present invention, the support frame is a tube having an
inner wall, having sinusoidal fold lines, wherein the pliant
material is sutured to the inner wall of the tube along suture
lines.
[0107] Furthermore, in accordance with another preferred embodiment
of the present invention, additional piece of PET is added below
the suture lines.
[0108] Furthermore, in accordance with another preferred embodiment
of the present invention, the device is incorporated with an
angioplasty balloon.
[0109] Finally, in accordance with another preferred embodiment of
the present invention, balloon has a central longitudinal axis that
runs along a flow path through the device, and a perimeter, the
balloon comprising four inflatable portions, one portion located
along a central axis and the other three located on the perimeter,
the pliant material in the form of leaflets is distributed about
the perimeter.
BRIEF DESCRIPTION OF THE FIGURES
[0110] To better understand the present invention and appreciate
its practical applications, the following Figures are provided and
referenced hereafter. It should be noted that the Figures are given
as examples only and in no way limit the scope of the invention as
defined in the appended claims.
[0111] FIG. 1 illustrates an implantable prosthetic tricuspid valve
in accordance with a preferred embodiment of the present invention,
suitable for percutaneous deployment using a stent or similar
deploying means, in its deployed-inflated position;
[0112] FIG. 2 depicts an implantable valve according to the present
invention mounted over a deploying stent with an inflatable
balloon;
[0113] FIG. 3 illustrates an implantable valve according to the
present invention mounted over a stent with an inflatable balloon,
in a crimped position;
[0114] FIG. 4 depicts implantable valve deployment in a natural
aortic valve position in accordance with the present invention;
[0115] FIG. 5 demonstrates manufacturing a polyurethane implantable
valve using a dipping technique according with the present
invention;
[0116] FIGS. 6a to 6e illustrate manufacturing of an implantable
valve by forging according to the present invention;
[0117] FIGS. 7a and 7b demonstrate composite valve, which has
polyurethane (PU) leaflets and PET tubular-crown shaped
construction, according to the present invention;
[0118] FIGS. 8a and 8b depict a manufacture process of a composite
valve made of flexible PU leaflets, rigid PU construction for
mounting and a PET tubular end;
[0119] FIGS. 9 to 9i demonstrate different methods of attachment
between the valve and stent according to the present invention;
[0120] FIG. 10 illustrates a dipping mandrel with an extra portion,
which improves the sealing ability of the valve, according to the
present invention;
[0121] FIG. 11a to 11c illustrate a valve mounted on a stent with
an extra support, which improves the force distribution on the
valve material and facilitates prolonged durability of the valve,
according to the present invention;
[0122] FIGS. 12a to 12c depict a valve with rigid supports
according to the present invention, located substantially in the
center of its leaflets. This design allows the valve leaflets to
perform without outer support;
[0123] FIGS. 13a to 13c illustrate the manufacturing of a
reinforced PU tube composed of strong fiber from PU, PET or other
and a softer PU coating, for serving as the supporting
structure;
[0124] FIGS. 14a to 14c demonstrate incorporation of heavy metal
markers on the stent, according to the present invention. These
markers allow orientation control while positioning the device at
the required location;
[0125] FIGS. 15a to 15c demonstrate a valve with radio-opaque
coating, according to the present invention, which allows imaging
of the valve motion under angiogram;
[0126] FIGS. 16a to 16c illustrate a procedure, which helps in
accurate positioning the valve device with respect to the
longitudinal orientation;
[0127] FIGS. 17a and 17b describe a valve device according to the
present invention, comprising one valve assembly mounted on a stent
and an additional portion with a stent only. This allows placing
the device in a way that coronaries are not blocked, longitudinal
positioning thus becomes less sensitive and the extra stent
decreases the risk of device migration within the vasculature;
[0128] FIGS. 18a and 18b demonstrate a crimping device according to
the present invention, which can crimp a valve device in the
operating theater as part of the implantation procedure;
[0129] FIGS. 19a to 19c depict a crimping machine according to the
present invention, similar to the one described in FIG. 18 with a
different mechanical method;
[0130] FIGS. 20a and 20b demonstrate a valve according to the
present invention, made of a tube mounted on a stent. During
systole the tube is fully open and during diastole the tube
collapses according to the mounting geometry providing tight
sealing;
[0131] FIG. 21 depicts a stent structure according to the present
invention, with built-in mounting portions of constant length,
which allow valve mounting;
[0132] FIG. 22 depicts yet another preferred embodiment a valve
assembly in accordance with the present invention, having dilated
supports;
[0133] FIGS. 23a to 23e depict stages in a method of manufacturing
an implantable prosthetic valve in accordance with another
preferred embodiment of the present invention;
[0134] FIGS. 24a to 24c illustrate a support frame of an
implantable prosthetic valve having means for mounting valve
leaflets in accordance with a preferred embodiment of the present
invention that can form a tricuspid valve. FIG. 24a depicts an
isometric view of the frame, and FIG. 24b depicts a cross-sectional
view of the means for mounting a valve leaflet in details, provided
with a valve leaflet. FIG. 24c depicts further details of
attachment means for the attachment method;
[0135] FIGS. 25a to 25d illustrate an implantable prosthetic valve
in accordance with another preferred embodiment of the present
invention. FIGS. 25a and 25b depict an isometric view and an upper
view of the valve assembly, respectively, and FIGS. 25c and 25d
illustrate upper views of two optional constructions for the means
for mounting leaflets;
[0136] FIGS. 26a to 26c illustrate a tricuspid valve in accordance
with yet another preferred embodiment of the present invention,
provided with a self-expandable frame. FIG. 26a is the valve in its
fully expanded diameter, FIG. 26b is a tapered tool which assists
in inserting the valve into an introducing tube, and FIG. 26c shows
the valve assembly inside a restriction tube, ready to be inserted
into a introducing sheath;
[0137] FIG. 27 illustrates an isometric view of an implantable
prosthetic valve in accordance with another preferred embodiment of
the present invention having hooks designated to anchor the valve
assembly to body ducts;
[0138] FIG. 28 illustrates a partial view of an implantable
prosthetic valve in accordance with yet another preferred
embodiment of the present invention. The commissural attachment is
showed in details;
[0139] FIGS. 29a and 29b illustrate an isometric view and an upper
cross-sectional view, respectively, of an attachment assembly of a
valve's frame to leaflets in accordance with a preferred embodiment
of the present invention;
[0140] FIGS. 30a to 30c illustrate an isometric view, a
cross-sectional view and a flattened view, respectively, of an
attachment assembly of a valves frame to leaflets in accordance
with another preferred embodiment of the present invention. FIG.
30c is a side view showing two pieces of pericardium before the
attachment to the frame;
[0141] FIGS. 31a and 31b illustrate an exploded view and an
isometric view, respectively, of a commissural attachment in
accordance with a preferred embodiment of the present invention
depicting the attachment technique;
[0142] FIGS. 32a and 32b illustrate an isometric view of an
attachment between leaflets and the frame in accordance with yet
another preferred embodiment of the present invention;
[0143] FIGS. 33a to 33d illustrate different views and portions of
an attachment between a pericardium and a frame in accordance with
yet another preferred embodiment of the present invention,
demonstrating another method of attachment in accordance with the
preferred embodiment;
[0144] FIGS. 34a to 34c illustrate an isometric view of an
attachment between a pericardium and a valve in accordance with yet
another preferred embodiment of the present invention demonstrating
another method of attachment. In FIGS. 34b and 34c, a deployed
portion and the folded portion, respectively, are shown;
[0145] FIGS. 35a to 35c illustrate an isometric and cross-sectional
upper views, respectively, of attachment techniques between a
pericardium leaflet and a valve's frame in accordance with another
preferred embodiment of the present invention;
[0146] FIGS. 36a and 35b illustrate an isometric view of a
commissural assembly in accordance with a preferred embodiment of
the present invention demonstrating a method of forming one;
[0147] FIGS. 37a to 37c illustrates a commissural assembly in
accordance with another preferred embodiment of the present
invention, where the connecting bar functions as a flexible support
and has integral attachment means to the frame. FIG. 37b is an
isometric view of the connecting bar;
[0148] FIGS. 38a to 38g illustrate isometric views of flexible
commissural supports and the method of attaching them to a
pericardium and a frame and valve in accordance with preferred
embodiments of the present invention;
[0149] FIGS. 39a and 39b illustrate an isometric view of a
commissural attachment in accordance with yet another preferred
embodiment of the present invention, demonstrating the attachment
of the pericardium to the support by means of a shaped compressing
member;
[0150] FIGS. 40a to 40c illustrate an isometric view of a bicuspid
valve mounted on a frame in accordance with yet another preferred
embodiment of the present invention. FIGS. 40b and 40c depicts a
cross-sectional side view and an isometric view, respectively, of
the pericardium that is sutured to a PET tube in the form of
pockets;
[0151] FIGS. 41a to 41d illustrate isometric views of an
implantable prosthesis tricuspid valve in accordance with yet
another preferred embodiment of the present invention;
[0152] FIGS. 42a and 42b illustrate an isometric view of an
implantable prosthetic valve in accordance with yet another
preferred embodiment of the present invention, having a different
commissural attachment. FIG. 42b depicts the attachment in
details;
[0153] FIGS. 43a and 43b illustrate an isometric view of an
implantable prosthetic valve in accordance with yet another
preferred embodiment of the present invention. FIG. 43a depicts the
commissure that are pre-sutured in a tapered shape;
[0154] FIGS. 44a to 44c illustrate an isometric view of an
implantable prosthetic valve in accordance with yet another
preferred embodiment of the present invention, with additional
pieces of PET used for sealing and protecting the pericardium;
[0155] FIGS. 45a to 45d illustrate an isometric view of an
implantable prosthetic valve in accordance with yet another
preferred embodiment of the present invention, having leaflets
sutured to a pre-shaped PET tube and optional leaflet-tube
attachments in details;
[0156] FIGS. 46a and 46b illustrate an exploded view and an upper
cross-sectional view of an implantable prosthetic valve assembly in
accordance with yet another preferred embodiment of the present
invention;
[0157] FIGS. 47a to 47c illustrate a partial cross-sectional side
view of an inflating balloon in accordance with a preferred
embodiment of the present invention. The balloon is a part of an
implantable prosthetic valve delivery system. FIGS. 47b and 47c are
cross sectional upper views in the inflated and deflated positions,
respectively; and
[0158] FIGS. 48a and 48b illustrate a partial cross-sectional side
view and an upper cross-sectional view of an inflating balloon in
accordance with another preferred embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0159] A main aspect of the present invention is the introduction
of several novel designs for an implantable prosthetic valve.
Another aspect of the present invention is the disclosure of
several manufacturing methods for implantable prosthetic valves in
accordance with the present invention. A further aspect of the
present invention is the provision of novel deployment and
positioning techniques suitable for the valve of the present
invention.
[0160] Basically the implantable prosthetic valve of the present
invention comprises a leafed-valve assembly, preferably tricuspid
but not limited to tricuspid valves only, consisting of a conduit
having an inlet end and an outlet, made of pliant material arranged
so as to present collapsible walls at the outlet. The valve
assembly is mounted on a support structure such as a stent adapted
to be positioned at a target location within the body duct and
deploy the valve assembly by the use of deploying means, such as a
balloon catheter or similar devices. In embodiments suitable for
safe and convenient percutaneous positioning and deployment the
annular frame is able to be posed in two positions, a crimped
position where the conduit passage cross-section presented is small
so as to permit advancing the device towards its target location,
and a deployed position where the frame is radial extended by
forces exerted from within (by deploying means) so as to provide
support against the body duct wall, secure the valve in position
and open itself so as to allow flow through the conduit.
[0161] The valve assembly can be made from biological matter, such
as a natural tissue, pericardial tissue or other biological tissue.
Alternatively, the valve assembly may be made form biocompatible
polymers or similar materials. Homograph biological valves need
occasional replacement (usually within 5 to 14 years), and this is
a consideration the surgeon must take into account when selecting
the proper valve implant according to the patient type. Mechanical
valves, which have better durability qualities, carry the
associated risk of long-term anticoagulation treatment.
[0162] The frame can be made from shape memory alloys such as
nickel titanium (nickel titanium shape memory alloys, or NiTi, as
marketed, for example, under the brand name Nitinol), or other
biocompatible metals. The percutaneously implantable embodiment of
the implantable valve of the present invention has to be suitable
for crimping into a narrow configuration for positioning and
expandable to a wider, deployed configuration so as to anchor in
position in the desired target location.
[0163] The support stent is preferably annular, but may be provided
in other shapes too, depending on the cross-section shape of the
desired target location passage.
[0164] Manufacturing of the implantable prosthetic valve of the
present invention can be done in various methods, by using
pericardium or, for example, by using artificial materials made by
dipping, injection, electrospinning, rotation, ironing, or
pressing.
[0165] The attachment of the valve assembly to the support stent
can be accomplished in several ways, such as by sewing it to
several anchoring points on the support frame or stent, or riveting
it, pinning it, adhering it, or welding it, to provide a valve
assembly that is cast or molded over the support frame or stent, or
use any other suitable way of attachment.
[0166] To prevent leakage from the inlet it is optionally possible
to roll up some slack wall of the inlet over the edge of the frame
so as to present rolled-up sleeve-like portion at the inlet.
[0167] Furthermore, floating supports may be added to enhance the
stability of the device and prevent it from turning inside out.
[0168] An important aspect of certain embodiments of the present
invention is the provision of rigid support beams incorporated with
the support stent that retains its longitudinal dimension while the
entire support stent may be longitudinally or laterally
extended.
[0169] The aforementioned embodiments as well as other embodiments,
manufacturing methods, different designs and different types of
devices are discussed and explained below with reference to the
accompanying drawings. Note that the drawings are only given for
the purpose of understanding the present invention and presenting
some preferred embodiments of the present invention, but this does
in no way limit the scope of the present invention as defined in
the appended claims.
[0170] Reference is now made to FIG. 1, which illustrates a general
tricuspid implantable prosthetic valve 20 in accordance with a
preferred embodiment of the present invention, suitable for
percutaneous deployment using an expandable stent or similar
deploying means, shown in its deployed position. A valve assembly
28 comprises a conduit having an inlet 24 and an outlet 26, the
outlet walls consisting of collapsible pliant material 29 that is
arranged to collapse in a tricuspid arrangement. The valve assembly
28 is attached to an annular support stent 22, the one in this
figure being a net-like frame designed to be adapted to crimp
evenly so as to present a narrow configuration and be radially
deployable so as to extend to occupy the passage at the target
location for implantation in a body duct. Support beams 23 are
provided on annular support stent 22 to provide anchorage to valve
assembly 28. Support beams 23 are optionally provided with bores 25
to allow stitching of valve assembly 28 to support beams 23 by
thread, wires, or other attachment means.
[0171] In the embodiment shown in FIG. 1, a cuff portion 21 of the
valve assembly 28 is wrapped around support stent 22 at inlet 24 to
enhance the stability. Preferably cuff portion 21 of valve material
28 is attached to support beams 23.
[0172] Note that the entire valve structure is adapted to be
radially crimped and radially expanded, and this lends to provide
ease of navigation through narrow passages in the vasculature
during positioning of the device and adequate deployment on the
final location. This is made possible by the provision of a
collapsible support stent structure. However, the support beams
remain at all times constant at their length and thus are suitable
for serving as the pliable valve assembly's anchorage. The valve
assembly is attached to the support stent at the support beams, and
due to their constant length there is no need for slack material as
the attachment points (25) remain at constant distances regardless
of the position of the valve device (crimped or deployed). This is
an important feature for this means that the manufacturer of the
valve device can make sure the valve assembly is secured and
fastened to the support stent at all times. In prior art
implantable valve devices the entire support stricture changes its
dimensions from its initial first crimped position and final
deployed position, and this means that in the attachment of the
valve assembly to the support structure one must take into
consideration these dimension changes and leave slack material so
that upon deployment of the device the valve assembly does not tear
or deform. In the valve device of the present invention there is no
relative movement between the valve assembly and the support beams
(along the longitudinal central axis of the device). As a result,
the valve device of the present invention acquires greater
durability and is capable of withstanding the harsh conditions
prevailing within the vasculature and especially the millions of
cycles of stress applied by the blood pressure.
[0173] The fixed attachment of the valve assembly to the support
stent in the valve device of the present invention results in
greater stability, enhanced safety, better sealing and consequently
longer lifespan. The novel design of the valve device of the
present invention leads to longitudinal strength and rigidity
whereas its collapsible support structure results in radial
flexibility.
[0174] FIG. 2 depicts an implantable valve 30 mounted on a
deployable stent 32. The valve assembly 34 is attached to the
deployable support stent 32 (dotted lines) along three
substantially equidistant and substantially parallel support beams
40 of constant length, which are part of stent 32. The attachment
of valve assembly 34 to stent 32 is facilitated by the support
beams 40 to which valve assembly 34 is stitched with thread or
fiber 46 (through bores 42 of support beams 40). Outlet leafs 38,
which are a slack portion of the valve assembly, dangle inwardly,
and the whole device is carried by an inflatable balloon 48, which
serves as the deploying device. A portion of the valve assembly 34
at an inlet zone 45 is optionally rolled over support stent 32 at
the inlet, making up a rolled sleeve, which enhances tie sealing of
the device at the valve inlet.
[0175] FIG. 3 demonstrates an implantable valve mounted to a stent
50 with an inflatable balloon 52, in a crimped position. The
support stent 50 is initially crimped about the balloon 52 so that
is presents a narrow cross-section and is thus suitable for
percutaneous catheterization and deployment.
[0176] FIG. 4 depicts an implantable valve deployment in a natural
aortic valve position. The implantable valve is advanced while
mounted over the balloon 52 until it reaches the desired target
location 54 in a body duct, for example, aorta 56. The balloon is
inflated and the support stent 50 expands radially to take up its
position.
[0177] FIG. 5 demonstrates the manufacture of a polyurethane valve
in a dipping technique. A dipping mandrel 60 is provided with a
tubular portion 62 with surfaces 64 that correspond to the
collapsible valve leaflets to be manufactured. Mandrel 60 is dipped
into a dissolved polyurethane bath 66 and is coated with a
polyurethane coating in the desired form of the valve. Then, after
the polyurethane coating has hardened sufficiently, the completed
valve is removed from mandrel 60.
[0178] FIGS. 6a to 6e illustrate manufacturing an implantable valve
by forging. A suitable tubularly shaped material 74 is placed
tightly on a tubular portion 68 of mandrel 67, covering the cusp
portion 69. Flexible inserts 76 are pressed to mandrel 67, forging
the tubular material to mandrel shape 80. A tapered ring 70 holds
the flexible inserts in place as the whole mold is placed in a hot
oven regulated to a desired temperature, which is lower than the
material's melting point. FIG. 6e illustrates a sectional side view
of the mandrel and a cross cut portion of the mold. The mold is
made to press inwardly on the mandrel, which is covered with the
valve material. As a result the material takes up the desired
shape. The materials used can vary, for example, polyurethane (PU),
polyethylene terphthalate (PET), or any other suitable material,
which may be formed by heating.
[0179] FIGS. 7a and 7b demonstrate a method of manufacturing a
composite valve, which has PU leaflets and PET tubular construction
with a crown shape. PU is an excellent fatigue resistant material
but is sensitive to tear. The PU is reinforced by the PET crown to
allow safe attachment to a stent by means of stitching, riveting,
or any other suitable attachment method. A PET crown 86 is placed
on a mandrel 87, which is then (turned and) dipped in a container
of dissolved PU. The manufactured device is a valve assembly having
leaflets 88 composed of pure PU, and thus fatigue resistant, and a
main body made of PET with protruding attachment portions 90
suitable for attachment built in the PU.
[0180] FIGS. 8a and 8b demonstrate a method of manufacturing a
composite valve, which is based on flexible PU 92 for as the main
body of the valve, rigid PU support beams 94 serving for the
attachment area, and PET sleeve 96 portions for the valve inlet.
The need for a rigid portion for attachment (support beams 94) is
explained by the tendency of the flexible, fatigue resistant
material to tear as already explained. The advantage of the stiff
PU support beams is that they are chemically adhered to the main
body, and this improves the overall durability of the valve due to
reduction of inner forces and friction in the attachment area
specially attachment between two different materials. The valve is
dipped in the method mentioned with reference to FIG. 5, and the
rigid PU support beam 94 is created by way of mold injection,
machining or any other suitable way. The rigid PU support beam 94
is placed on the valve and then dipped into the container of
dissolved PU. This is done while the valve is positioned on the
mandrel (not shown). This method provides the ability to composite
several materials into one body and, by that, gain the advantage of
the various properties of the materials as they are needed in
different areas of the prosthesis.
[0181] FIGS. 9 to 9i demonstrate different methods of attachment
between a valve assembly and the support stents. A valve assembly
99 shown in FIG. 9 is incorporated into valve 100 shown in FIG. 9a,
where a support stent 102 is attached to valve assembly 99 through
support beam 106. A detail is shown in FIG. 9b, where, in
cross-section, it can be seen that layer 108 is an optional inner
support made of stainless steel or rigid polymeric material, valve
assembly 99 comprises a PET layer 105 coated with a PU layer 104,
with the outer support beam 106. Connector 107 is a connecting wire
made of a strong material, such as stainless steel. FIG. 9c
illustrates an alternative arrangement for attachment by a rivet
109, and in FIG. 9d the attachment is achieved by a suture 110.
[0182] FIGS. 9e to 9g show an attachment method comprising shaped
rigid members 116, preferably made from metal, which tightly hold
the PU valve material 118 by fitting in between a PU U-shaped nest
120 and are attached to a stent 122 by extruding portions 124 that
are provided on U-shaped rigid member 116, which fit the bores 126
of the support beam 128 of the stent 122. FIGS. 9h and 9i show
another attachment method, where rigid support beams in the form of
frame construction 132 are provided, and the valve assembly pliant
material 135 made of a tubular material is inserted through a gap
137 in the frame. After insertion, a fastening rod 133 is inserted
through the pocket formed between the pliant material and the frame
and holds the valve in position.
[0183] FIG. 10 illustrates a dipping mandrel 139 with an extending
portion 141, which improves the sealing ability of the valve. Since
the valve is attached to a collapsible stent and is itself
collapsible, it is difficult to determine the exact shape of the
valve after crimping and deploying. It is of major importance that
sealing will be achieved. By adding the extension 141 the leaflets
are made longer than needed to exactly close the outlet, and
therefore when they are in the collapsed state, substantial
portions of the leaflets fall on each other creating better
sealing.
[0184] FIGS. 11a to 11c illustrate a valve assembly mounted on a
support stent 144 with interlaced strengthening wire 146, which
improves the force distribution on the valve material and
facilitates prolonged durability of the valve. The support is in
the form of a wire, which has a crown shape as the shape of the
three cusp valve base 148, it also has the ability to be crimped
150 to a small diameter, together with the stent, valve and
balloon, as shown in FIG. 11b. The forces applied to the valve edge
148 while working, are applied to the attachment points, by making
the attachment line longer we reduce the force on each attachment
point. In this support method the valve is attached by suturing 152
the entire line to the extra support wire 146. This wire can be
made of stainless steel, nickel titanium alloy such as nitinol, or
polymeric material. The support suture renders the valve assembly
default fault lines where the valve material more readily flexes,
thus ensuring proper operation of the valve flaps (leaflets).
Optionally the valve assembly shown in FIGS. 11a to 11c can be
mounted on a support stent such as the one described herein or
similar supporting structures. The strengthening wire is interlaced
in the valve assembly at the outlet of the conduit so as to define
a fault line about which the collapsible slack portion 154 of the
valve assembly may flap.
[0185] FIGS. 12a to 12c depict a valve device provided with a stent
159 and substantially equidistant rigid support beams 160,
interlaced or attached to the slack portion of the valve assembly
material 161, arranged longitudinally. This design allows the valve
leaflets to perform without outer support. The support in standard
valves is by tying the upper edge of the cusp to a rigid
embodiment, so that it reacts to the load as a suspension bridge.
In this new design the prevention of collapsing is achieved similar
to an Indian tent, i.e., the rigid supports lean on each other 162
when the valve is closed but do not interfere in opening 164 when
the valve is open.
[0186] FIGS. 13a to 13c illustrate the manufacturing of a valve
assembly in accordance with another preferred embodiment of the
present invention. At first a polyurethane thread line 170 is fed
from a PU supply 172, and coiled around a cylindrical drum 174 to
form coil 176. Then, drum 174 with coil 176 is dipped in a PU bath
177, and a second layer 178 of the PU coats coil 176, making it a
stronger construction capable of withstanding tearing forces both
laterally and in other directions. Incorporating two different
types of materials--such as PU and PET--may render greater
durability and endurance to the valve assembly. This material is an
alternative material to be used in the forging method shown in FIG.
6.
[0187] FIGS. 14 to 14c demonstrate the incorporation of heavy metal
markers on the stent, which markers allow observation and thereby
adjustment of orientation while placing the device in the required
location. Heavy metals are radiopaque, that is, they are
conspicuous on an angioscopic image, which is a two-dimensional
image. Since the coronary artery ostia 237 and 238 are located near
the typical valve deployment location and must stay open, it is
extremely important to make sure that the deployed valve assembly
is not blocking a coronary ostium. In some cases the stent is lower
than the ostium and in those cases it will stay open, but in some
cases as shown in these figures it is necessary to make sure that
the stent portion 239 that is connecting the valve supports 235 is
opposite the coronary ostia, and in that way the blood supply is
preserved through the stent struts. Two heavy metal markers 232 are
attached at the outlet side, one marker 230 at the inlet side. It
is possible to adjust the angiogscopic view to the plane of the
left coronary as shown in FIG. 14b and anatomically locate the
other accordingly. If the two upper markers 232 are placed in the
radiographic two dimensional image, one on top of the other, and
the low marker 230 on the opposite side, we make sure that the
coronaries are open to blood flow as seen in FIG. 14c. Gold,
platinum, iridium or tantalum are all biocompatible materials
suitable for the markers described above.
[0188] FIGS. 15a to 15c illustrate a valve with a portion of
radio-opaque material 267 such as a thread of gold at the sealing
edge. When a valve is implanted, it is very important to have clear
indications of how the valve is functioning in vivo; pressure
measurements, flow visualization, and doppler measurements are
utilized. It is also possible to examine the valve by ultrasound
methods, however, observing the opening and closing of the valve
cusps on a monitor. FIG. 15b is an angiographic image 268 of the
open valve, while image 169 in FIG. 15c is the closed position as
seen on the angiogram.
[0189] FIGS. 16a to 16c illustrate a procedure, which helps in
placing the device in the longitudinal position. It is very
important to place the device in the correct longitudinal position,
for if it is too deep in the left ventricle it may interfere with
the mitral valve function by improper closing or function of the
valve. If it is positioned too high it may migrate, it may leak via
the sinus cavities, which are located around it, and/or it may
block the coronaries. It is a necessary task to position the valve
prosthesis in a narrow target location. In FIG. 14 a method of
lateral orientation placement is shown, and FIGS. 16a to 16c
illustrate a longitudinal positioning. The valve device (the valve
assembly and the support stent) is placed on an inflatable balloon
catheter, comprising double independently inflatable chambers 303,
305, and is inserted into the left ventricle 302 in the crimped
position and guided over a guiding stylet or guide wire 300. The
balloon, which is larger than the annulus diameter when inflated,
is inflated in the left ventricle 302, and then the whole device is
pulled slightly backwards. The balloon is supported on the inner
part of the annulus 303, allowing positioning of the device in the
exact desired position. In addition, it temporarily blocks the
blood flow, and that improves the ability to hold the device in
place while inflating it. The next step is inflating the second
balloon 305, which deploys the valve device in the desired
location.
[0190] The method for deploying an implantable prosthetic valve
device at the natural aortic valve position at the entrance to the
left ventricle of a myocardium of a patient, as depicted in FIGS.
16a, 16b and 16c, comprises the steps of:
[0191] (a) providing a balloon catheter having a proximal end and a
distal end, having a first and second independently inflatable
portions, the first inflatable portion located at the distal end of
the catheter and the second inflatable portion adjacently behind
the first inflatable portion;
[0192] (b) providing a guiding tool for guiding the balloon
catheter in the vasculature of the patient;
[0193] (c) providing a deployable implantable valve prosthesis
device adapted to be mounted on the second inflatable portion of
the balloon catheter
[0194] (d) guiding the balloon catheter through the patient's aorta
using the guiding tool, the valve device mounted over the second
inflatable portion of the balloon catheter until the first
inflatable portion of the balloon catheter is inserted into the
left ventricle, whereas the second inflatable portion of the
balloon catheter is positioned at the natural aortic valve
position;
[0195] (e) inflating the first inflatable portion of the balloon
catheter so as to substantially block blood flow through the
natural aortic valve and anchor the distal end of the balloon
catheter in position;
[0196] (f) inflating the second inflatable portion of the balloon
catheter so as to deploy the implantable prosthetic valve device in
position at the natural aortic valve position;
[0197] (g) deflating the first and second inflatable portions of
the balloon catheter; and
[0198] (h) retracting the balloon catheter and removing it from the
patient's body.
[0199] FIG. 17 describes a positioning of a valve device 310 using
an additional deployable stent 320. There are several problems that
may be encountered while deploying the stent and valve in the
aortic valve location: blockage of coronaries may occur that is
dangerous if the diameter of the stent is similar to that of the
coronaries aortic root 309. Secondly, migration of the whole device
may also occur, which is a dangerous possibility, and there is the
problematic challenge of exact positioning of the valve device that
is very difficult to accomplish, as already explained. The newly
special designed device with a double diameter inflatable balloon
and double stent design allows placement of the device in a way
that coronaries will not be blocked because of a safe difference
that is kept between the diameters, longitudinal placing is less
sensitive because of the small diameter which ensures prevents over
expansion of the valved prosthesis. The distal stent 320, which
contains no valve, is expanded into the ascending aorta, while the
proximal stent 310 is placed simultaneously in the annular
position. This placement method is less challenging due to the
smaller diameter of the proximal stent 310 which ensures that the
mitral valve is not deformed by over-expansion as the dimensions
are preserved, and the additional stent decreases the risk of
device migration. It is safer to over dilate in the aorta, which is
not true for the annulus.
[0200] The method for deploying an implantable prosthetic valve
device at the natural aortic valve position at the entrance to the
left ventricle of a myocardium of a patient, as depicted in FIGS.
17a and 17b, comprises the steps of:
[0201] (a) providing a balloon catheter having a proximal end and a
distal end, having a first and second independently inflatable
portions, the first inflatable portion located at the distal end of
the catheter and the second inflatable portion adjacently behind
the first inflatable portion;
[0202] (b) providing a guiding tool for guiding the balloon
catheter in the vasculature of the patient;
[0203] (c) providing a deployable implantable valve prosthesis
device adapted to be mounted on the first inflatable portion of the
balloon catheter, and a deployable annular stent device adapted to
be mounted over the second inflatable portion of the balloon
catheter, the deployable implantable valve prosthesis device and
the deployable annular stent kept at a predetermined distant
apart;
[0204] (d) guiding the balloon catheter through the patient's aorta
using the guiding tool, the valve device mounted over the first
inflatable portion of the balloon catheter and the deployable
annular stent mounted over the second inflatable portion of the
balloon catheter, until the first inflatable portion of the balloon
catheter is positioned at the natural aortic valve position;
[0205] (e) inflating the second inflatable portion of the balloon
catheter so that the deployable stent device is deployed within the
aorta thus anchoring the deployable annular stent and the coupled
valve device in position;
[0206] (f) inflating the first inflatable portion of the balloon
catheter so as to deploy the implantable prosthetic valve device in
position at the natural aortic valve position;
[0207] (g) deflating the first and second inflatable portions of
the balloon catheter; and
[0208] (h) retracting the balloon catheter and removing it from the
patient's body.
[0209] FIGS. 18a and 18b illustrate an accessory crimping device
that is adapted to crimp a valve device in the operating theater as
part of the implantation procedure. The crimping device 330
comprises several adjustable plates that resemble a typical SLR
camera variable restrictor. It is comprised of simultaneously
movable plates 332 each provided with a blade 334, that are equally
dispersed in a radial symmetry but each plate moves along a line
passing off an opening in the center, all plates equidistant from
that center opening 336. Initially (see FIG. 18a) the plates are
drawn apart providing a large enough opening for the implantable
valve to be positioned within that opening. When the plates are
drawn towards the center (see FIG. 18b), the opening 336 reduces in
size but still retains the annular shape, and this facilitates the
crimping of the valve frame to a small dimension suitable for
percutaneous positioning.
[0210] FIGS. 19a depicts a crimping method for the support stent of
the valve prosthesis device of the present invention, whereby stent
340 is crimped, that is, compressed or curled. In FIG. 19b a
crimping device 343 is shown, comprising a body having an annular
void in which an expanded stent is positioned. Lever 346 is
connected to the end 347 of the stent and as the lever is pulled
the stent is curled or compressed about axle 345 into a compressed
position 349 (FIG. 19c).
[0211] FIGS. 20a and 20b depict a valve made of a simple tube
mounted to a stent 352. During systole period the tube is fully
open and during diastole period the tube collapses according to the
mounting geometry 357 and achieves sealing.
[0212] FIG. 21 describes a newly designed support stent 360 in its
open position. Three of the longitudinal struts 362 are full and
thick and always stay with their original constant size, serving as
anchoring support. Each of these struts 362 is provided with a
plurality of bores 364, which are later used for mounting the valve
assembly (not shown) and tying it to stent 360. Between struts 362
a web-like construction is provided, which is capable of being
crimped to a narrow state and capable of being deployed again to a
wider state.
[0213] FIG. 22 illustrates another preferred embodiment of an
implantable prosthetic valve according to the present invention. It
comprises a metal tube 370, having three portions with a thicker
wall 371 than in the rest of the tube 370, these areas form the
longitudinal columns 372 in the construction, after the tube is cut
to its final form. The advantage of such a construction is in its
superior bending strength, in specific required portions of the
construction, with minimal interference to the crimped volume of
the whole construction.
[0214] FIG. 23a to 23c depict a new method of manufacturing an
artificial or biological crimpable valve device. A piece of fabric
material 370 (FIG. 23a), is dipped in PU to create a portion which
is later formed into valve leaflets 371 (FIG. 23b). This composite
material 371 is then attached to an additional piece of fabric such
as PET 372 by means of stitching, suturing or other attaching
technique 373 (FIG. 23c). The resulting fabric 375 is cut along
stitching line 373 leaving enough material to later suture the
valve assembly to the support construction. It is then formed to a
tubular shape and stitched 374 (FIG. 23d). The tubular valve is
then attached to a support construction 380 by suturing the bottom
part around the valve 379 tightly to prevent leakage, and around
the cut fabric line 376 (FIG. 23e). This open wall structure 378
allows blood flow to the coronary arteries. The valve is later
placed with the coronary artery between the support columns 385.
Additional variations of this can be made by replacing the
composite material 371/370 with a biological patch such as a
suitable pericardium patch. In some cases it is possible to make
the same valve without cutting the fabric 372 with the shaped cut
376, and by that create a valve with an outer tubular shape. The
embodiment of FIGS. 23a to 23c is easy to manufacture as it is
generally flat throughout most of the production process and only
at the final stage of mounting on the support stent is it given a
three-dimensional form.
[0215] Reference is now made to FIG. 24a illustrating a frame of an
implantable prosthetic valve having means for mounting valve
leaflets in accordance with a preferred embodiment of the present
invention that can form a tricuspid valve. FIG. 24a depicts an
isometric view of the frame and FIG. 24b depicts a cross sectional
view of the means for mounting valve leaflets 430 in detail. A
frame 420, which is suitable for crimping and expanding, has three
support beams 422 for mounting leaflets positioned substantially
symmetrically about the circumference of the frame. Frame 420 is
shown in FIG. 24a in its deployed state. Support beam 422 has a "U"
shaped lateral cross section, or profile (shown clearly in FIG.
24b) that is designed to attach to a commissure of the valve
structure. The "U" shape can be produced by extrusion, wire cutting
or by welding the "U" profile to the frame's struts 421 at junction
points 424. Support beam 422 is provided with a series of bores 425
positioned along its back wall. Bores 425 are designated for
stitching the valve assembly by threads, wires, or other attaching
means.
[0216] FIG. 24b is a detailed cross-sectional view of one of the
support beam 422. Two pericardial leaflets 430 are inserted through
a U-shaped, or forked holder 428 that compresses and restricts the
leaflets in the U-shaped profile. Leaflets 430 are folded to both
sides of the support beam 422. When holder 428 is compressed toward
the support beam 422, leaflets 430 are caught in-between holder 428
and support beam 422 so that the leaflets are kept in place. FIG.
24c is an exploded view of the holder, bar 426 has a series of
bores compatible for attachment to the frames support beam 422,
attachment being achieved by suture 423 or any other attachment
means. This attachment method allows attaching the leaflets to the
frame without puncturing it with sutures and needles. It is also
important that the leaflets are firmly held in place by the holder
428 so that it has no relative movement in respect to the rigid
frame; hence avoiding wear due to movements. Leaflets that are made
from pericardium are known to better withstand inner movements and
stresses and less to wear by movement against rigid, hard or sharp
bodies.
[0217] It is noted again that the entire valve structure is adapted
to be radially crimped and radially expanded. This feature imparts
the valve with the ability and ease to navigate through narrow
passages in the vasculature during positioning of the device. After
final positioning of the valve, the valve is deployed. This is made
possible by the provision of a collapsible support frame structure.
However, the length of the attaching means (the height of the
valve) remains at all times constant; thus suitable for serving as
the pliable valve assembly's anchorage. The leaflets are attached
to the support frame at the attaching means, and due to their
constant length there is no need for slack material as these
attachment points that remain at constant distances regardless of
the position of the valve assembly (crimped or deployed). This is
an important feature for this means that the manufacturer of the
valve device can make sure the valve assembly is secured and
fastened to the support frame at all times. In prior art
implantable valve devices, the entire support structure changes its
dimensions from its initial first crimped position to final
deployed position and this means that in the attachment of the
valve leaflets to the support structure one must take into
consideration these dimension changes and leave slack material so
that upon deployment of the device, the valve assembly does not
tear or deform. In the valve device of the present invention there
is no relative movement between the valve leaflets and the support
beams (along the longitudinal central axis of the device). As a
result, the valve device of the present invention acquires greater
durability and is capable of withstanding the harsh conditions
prevailing within the vasculature and especially the millions of
cycles of stress applied by the blood pressure.
[0218] The fixed attachment of the valve leaflets to the support
frame in the valve assembly device of the present invention renders
it greater stability, enhanced safety, better sealing and
consequently longer lifespan. The novel design of the valve device
of the present invention renders it longitudinal strength and
rigidity whereas its collapsible support structure renders it
radial flexibility.
[0219] FIGS. 25a to 25d illustrate an implantable prosthetic valve
in accordance with another preferred embodiment of the present
invention. FIGS. 25a and 25b depict an isometric view and an upper
view of the valve assembly, respectively and FIGS. 25c and 25d
illustrate upper views of two optional constructions for the means
for mounting leaflets. Pericardial leaflets 430 are mounted on a
deployable support frame 432. The frame is preferably made of three
segments that form a circular support frame when assembled (FIG.
25b). Pericardial leaflets 430 are attached to deployable support
frame 432 along three substantially equidistant and substantially
parallel beams 440, which are integral parts of support frame 432.
Leaflets 430 are attached to support frame 32 at support beams 440
by suturing 446 leaflets 446 to support beams 440 through bores 442
in beams. The frame segments that are preferably made from
stainless steel are pre-shaped 432 and can be formed in different
ways. FIG. 25c illustrates support frame segments 432a having beams
435a pointing inwardly. FIG. 25d illustrates support frame segments
432b having beams 435b that are outwardly pointing. The advantages
of this technique are the possibility to manufacture the frame
segments from sheets (as opposed to tube) and the ease of assembly
of the frame segments with the pericardial leaflets.
[0220] FIGS. 26a to 26c illustrate a tricuspid valve in accordance
with yet another preferred embodiment of the present invention,
provided with a self-expandable frame. FIG. 26a is an isometric
view of an implantable prosthetic valve 430 mounted on a
self-expandable frame 445. Implantable prosthetic valve 430
comprised of three valve leaflets is mounted on self-expandable
frame 445 so that each leaflet extends along an equidistant portion
of the frame and is sutured at both opposite sides to substantially
equidistant and substantially parallel beams 440. By using a
tapered tube 448 the whole assembly is crimped into a restriction
tube 449. FIG. 26b shows the crimped valve assembly 447 in its
final crimped diameter ready for insertion to the body. After
insertion into the desired location in the body the valve is
released from the restriction tube and as it is made of self
expandable material (like a shape-memory alloy), it expands back to
the original diameter and is anchored in place. In order to reduce
the diameter of the device from its fully expanded diameter to its
crimped diameter a special tapered tube is used, shown in FIG.
26c.
[0221] FIG. 27 illustrates an isometric view of an implantable
prosthetic valve in accordance with another preferred embodiment of
the present invention having hooks designated to anchor the valve
assembly to body ducts. An implantable prosthetic valve 450 is
placed in a natural aortic valve position 452. Implantable
prosthetic valve 450 comprises preferably three leaflets 430
mounted on a metallic support frame 455. The lower part of support
frame 455 is provided with attachment means, preferably with hooks
453. Hooks 453 assures that the valve assembly stays in place after
deployment, and cannot migrate to another position.
[0222] FIG. 28 illustrates a partial view of an implantable
prosthetic valve in accordance with yet another preferred
embodiment of the present invention. The commissural attachment is
shown in details. This figure demonstrates an attachment technique
that is used in order to attach pericardium leaflet 430 to a
metallic frame 420. A longitudinal bar 456 having a narrow slit 457
is used as the commissural attachment so that extensions 463 of
pericardium leaflet 430 are tightly inserted through slit 457.
Pericardium extensions 463 that are extended beyond slit 457 are
wrapped about a rigid bar 458 that acts as an anchoring means.
Every two extensions originating from two sides of slit 457 are
sutured to each other by a suture 459 at the side of rigid bar 458
opposite the slit. An additional suture 462 attaches the bottom
circumference of support frame 420 to leaflet 420 in order to
obtain sealing. The advantages of the described attachment are that
no sutures or suture holes are applied in the leaflet working area,
there are no concentrated stress points similar to stress point
caused by suturing, and the force distribution is along the
longitudinal bar 456. The narrow passage that is maintained through
slit 457 forces the leaflets to be static in respect to the support
so as to reduce abrasion.
[0223] The embodiments that will be shown herein after are optional
configurations of attachment between the leaflets and the support
frame.
[0224] FIGS. 29a and 29b illustrate an isometric view and an upper
cross sectional view, respectively, of an attachment assembly of a
valve's frame to leaflets in accordance with a preferred embodiment
of the present invention. The attachment is similar in principle to
the attachment shown in FIG. 28, however, longitudinal bar 456 is
further provided with an additional pole 465 that is attached to
longitudinal bar 456 so as to establish an integral part. Pole 465
is rounded so as to make sure the leaflets will not be abraded or
cut by sharp corners. In the cross sectional view shown in FIG.
29b, adjacent leaflets 460 can be seen compressed together and the
main protection goal is clearly shown.
[0225] FIGS. 30a to 30c illustrate an isometric view, a
cross-sectional view and a flatten view, respectively, of an
attachment assembly of a valves frame to leaflets in accordance
with another preferred embodiment of the present invention. Using
the method demonstrated in FIGS. 30a to 30c, the pericardial
leaflets are pre-cut to the desired shape 430 and are provided with
longitudinal bars 470 that are sutured to the leaflets creating a
longitudinal clamping effect (FIG. 30c). This allows distribution
of forces along the whole length of the attachment means as opposed
to concentrating the stresses in suture holes. In FIGS. 30a and
30b, an additional rigid portion 458 is added, creating a round
ending, which prevents the leaflets from being bent drastically at
the attachment point to portions of the frame 420. The attachment
to frame 420 is performed using sutures 459.
[0226] FIGS. 31a and 31b illustrate an exploded view and an
isometric view, respectively, of a commissural attachment in
accordance with a preferred embodiment of the present invention
depicting the attachment technique. A method of assembling
pericardial leaflets 430 to a frame 420 is demonstrated. A rigid
bar 476 provided with integral protrusions 478 is inserted through
bores 479 that are pre-cut in pericardial leaflets 430. Integral
protrusions 478 pass through a sheet of preferably PET (braided
polyester) fabric 475, and finally through bores 442 that are
provided in longitudinal bar 440 (the attachment means) of frame
420. After the assembling of the parts, as shown in FIG. 31b, the
parts are tightly assembled and bar protrusions 478 are attached to
bar 440 by welding, riveting or any other technique. The PET sheet
475 is folded and sutured tightly around bar 476 using suture
472.
[0227] FIGS. 32a to 32c illustrate an isometric view of an
attachment between leaflets and the frame in accordance with yet
another preferred embodiment of the present invention. An optional
method of attachment is demonstrated, in which a pericardium
leaflet 430 and bars 480 are sutured in an area as far as possible
from the working area of the leaflets. The pericardium is first
sutured using a suture 484 to bar 480 as seen in FIG. 32b, and then
folded and compressed. In order to firmly hold the pericardial
leaflets in place between bars 480, an integral connecting member
482 connects the two bars, allowing the bent portions of the bars
to be in parallel position, with the leaflets caught in between.
Then, an additional suture 483 connects the bottom side of the bar
to the leaflets so that while the valve is working, the leaflets do
not bear high stresses.
[0228] FIGS. 33a to 33d illustrate different views of portions of
an attachment between a pericardium and a frame in accordance with
yet another preferred embodiment of the present invention,
demonstrating another method of attachment in accordance with the
preferred embodiment. A connecting member 490 (shown in a deployed
position in FIG. 33d) is used to connect two pericardial leaflets
492 at the line of the commissurel. After being connected between
them, pericardial leaflets 492 are being connected to frame bar
480. Here again, the principal of compressing the leaflets between
two bent portions bars 491 of connecting member 490 and tightening
them using suture 484 without punctures in the working areas of the
pericardium is applied. However, connecting member 490 is provided
with a portion 493 that is positioned perpendicular to the two bent
portions bars 491 that holds the two leaflets together. Portion 493
is the connecting member to frame's bar 480. In FIG. 33a, the
junction point 495 between the portions of connecting member 491 is
placed at the upper part (outlet) of the frame so as to achieve a
rigid connection to the frame. In FIG. 33b, junction point 495 is
placed at the bottom part (inlet) of the frame so that the junction
point also functions as a spring. Comprehensive explanation of the
benefits of springs in commissures is discussed and shown in
respect with FIGS. 37 to 39.
[0229] FIGS. 34a to 34c illustrate an isometric view of an
attachment between a pericardium and a valve in accordance with yet
another preferred embodiment of the present invention demonstrating
another method of attachment. In FIGS. 34b and 34c, a deployed
portion and the folded portion, respectively, are shown. An
optional design for the attachment between the frame and the
leaflets is depicted. A connecting member 480 (shown clearly in
FIG. 34b) is being produced into a flat configuration using
laser-cutting. Connecting member 480, which is a part of the
frame's attachment means, is bent and then is ready for assembly
with the leaflets. Connecting member 480 comprises the main body as
well as a connection bar 497 and a flexible element 498 allowing
flexibility to the commissural. Leaflets 430 are threaded through
corresponding holes 481 in the structured connecting member 480 and
are sutured using a suture 482.
[0230] Reference is now made to FIGS. 35a, 35b, and 35c
illustrating isometric and cross-sectional upper views,
respectively, of attachment techniques between a pericardium
leaflet and a valve's frame in accordance with other preferred
embodiments of the present invention. FIGS. 35b and 35c depict
different techniques of commissural attachments: in FIG. 35b two
pieces of pericardial leaflets 500 are wrapped around a metallic
member 505 that is connected to a frame 501. Rigid members 503 are
positioned from both sides of metallic member 505 and then
tightened together and connected by a suture 502. All metallic
pieces are wrapped by PET fabric 508 in order to avoid direct
contact between the metallic pieces and the delicate pericardial
leaflets. The advantage of this structure is that after tightening
the suture, the whole commissure becomes static with no relative
movement between the portions. This improves the valve assembly's
resistance to abrasion. In addition, there are no needle holes or
sutures in the working area. FIG. 35c depicts a similar structure,
however, there is no use of rigid sidebars. After wrapping the
metallic member 505 with pericardial leaflets 500, a piece of PET
508 is used for tightening it to a tight bundle. In this case, the
suture line 502 is the borderline of the working area so it should
be designed so that stresses are in the best possible
distribution.
[0231] FIGS. 36a and 35b focus on the connection of the commissural
assembly to frame's protrusion 509, which is an integral part of
the frame and is the basis for the commissural attachment. This
example shows the use of four rigid longitudinal bars 503 connected
by a suture 502.
[0232] FIGS. 37a to 37c illustrate a commissural assembly in
accordance with another preferred embodiment of the present
invention, where the connecting bar functions as a flexible support
and has integral attachment means to the frame. FIG. 37b is an
isometric view of the connecting bar. Connecting bar 520 is
flexible and comprises a resilient material shaped in a "U" shape.
Connecting bar 520 is a part of commissural assembly 527 shown in
FIG. 37a. Connecting bar 520 is provided with protruding elements
521 that are acting as the means of attachment to the frame's bar
480. Protruding elements are designated to be inserted in
corresponding bores 442 in bar 480. It is optional to provide rods
527 which are integral parts of the "U" shaped member and replace
the suture 526 that connects the pericardium leaflet and the
connecting bar together, which is shown in FIG. 37a. FIG. 37c
depicts another method of attaching the flexible connecting bar 520
to the frame 480 by means of welding 523. Here the pericardial
leaflets 500 are attached to the connecting bar 520 by suture 526
inserted through a PET fabric 508 and two connecting bars 503,
which together create a tight bundle.
[0233] FIGS. 38a to 38g illustrate isometric views of flexible
commissural supports and the method of attaching them to a
pericardium and a frame a valve in accordance with preferred
embodiments of the present invention. FIGS. 38a to 38c demonstrate
incorporation of different design options of commissural springs.
The main purpose of a commissural spring is to reduce the impact
applied to the pericardial leaflets when the valve leaflets are
closed. If the structure is of a rigid nature, high stress will be
applied each time the valve closes. If a spring is added to the
structure, the spring will bear the highest portion of the impact,
thus reducing the stress applied to the leaflets during the time
the valve is closed. In FIG. 38a, a simple stainless steel spring
530 is connected to frame's bar 480 by threading a portion of the
spring into slots 538 as shown in more detail in FIGS. 38e and 38f.
In FIG. 38b, there is a similar spring 530 with leaflets 500
connected to it by one of the attachment methods, the commissural
support itself 530 is connected to the frame's bar 480 by spot
welding, laser welding or other attachment means. FIG. 38c depicts
a similar spring 534 having an additional spiral. The purpose of
such a spiral is to reduce stress in the spring and to allow the
fatigue requirements, which in the case of heart valves are of at
least 200 million cycles.
[0234] FIG. 38d illustrates an isometric view of a flexible
commissural support in accordance with yet another preferred
embodiment of the present invention, demonstrating the attachment
of the pericardium to the support. FIGS. 38e to 38g are the details
of the attachment to the frame. A commissural spring of a different
design 539 comprises a stainless steel wire of a small diameter in
respect with the springs described in FIGS. 38a to 38c. One
advantage of this structure is the distribution of stresses in the
spring and the ability to form a structure, which can be crimped to
a small diameter. Another advantage in this structure is that there
are no open edges of the spring, which can be dangerous when
operated; the open edges are protected in the frame's bar as shown
in FIGS. 38e to 38g, which show possible attachment methods of the
spring to the frame. In FIG. 38e, a frame's flat bar 480 has slots
531 cut to form slot tabs 538 for crimping the spring 530. FIG. 38f
shows pre-bending of the slots 527 and FIG. 38g shows the spring
legs 539 assembled firmly into the slot tabs 538.
[0235] FIG. 39a illustrates a technique of commissural assembly
using a shaped compressing member 511. The compression member 511
holds pericardial leaflets 500 firmly while pressing it in the
pivot points 513. A radial edge 514 is made in order to protect the
pericardium from abrasion. The whole assembly is held tightly
inside the compressing member 516. The commissural assembly is
connected to the frame by protrusion member 518, which fit bores in
the frames bar 480. FIG. 39b is an isometric view of the same
detail.
[0236] FIGS. 40a to 40c illustrate an isometric view of a bicuspid
valve mounted on a frame in accordance with yet another preferred
embodiment of the present invention. FIGS. 40b and 40c depict a
cross-sectional side view and an isometric view, respectively, of
the pericardium that is sutured to a PET tube in the form of
pockets. The valve assembly (in this case bicuspid) comprises a
crimpable frame 540, two pericardial leaflets 545, a PET skirt 543
and a connecting suture 547. The focus in this drawing is on the
pocket shape of the pericardium leaflet shown best in FIGS. 40b and
40c. One of the main goals in valve design, in general, is to
distribute the stresses in a homogenous way in the pericardium
material and the attachment areas. The design of the pericardium
leaflet as a pocket assists in distributing the stresses along
suture line 547; pericardium leaflet 545 is sutured to PET skirt
543 along connecting suture 547. PET skirt 543 is sutured to the
circumference of crimpable frame 540 at the bottom side 549 and at
the top 542 using one of the commissural attachments that are
described herein before regarding other embodiments. When
hydrodynamic pressure is applied on leaflets 545, the leaflets will
meet in the center 546 of frame 540 so as to seal the valve
assembly. The shape of the leaflets in the valve assembly is
determined by the boundary conditions, which in this case are the
suture lines. The suture lines can be designed to have an optimal
shape regarding the stress distribution in accordance with
geometrical restrictions.
[0237] Reference is now made to FIGS. 41a to 41d illustrating
isometric views of an implantable prosthesis tricuspid valve in
accordance with yet another preferred embodiment of the present
invention. FIG. 41a illustrates valve assembly 553 in an open
state. Valve assembly 553 comprises a frame 555 (rigid or
crimpable), pericardial leaflets 550 and bars 551. It is emphasized
that in the shown embodiment, the goal is to distribute the
stresses on the commissural arrangement in an optimal way.
Pericardial leaflets 550 are attached to bars 551 that act as
attachment means. The attachment means are positioned at the top
third of the valve; the bottom circumference is attached to the
frame in order to obtain full sealing. The middle part of the
pericardium is left slack. The pre-cut pericardium is cut in
greater dimensions than the frame; e.g., the height of the
pericardium leaflet is greater than the height of the frame, for
example, if the frame height is 15 mm, the pericardium will be cut
to a height of 18 mm so as to establish a slack portion in the
middle area of the valve assembly 553. FIG. 41b depicts the valve
assembly in a closed state. The slack portion of the pericardium
collapses toward the middle while creating a small pocket shape
554, which assists in the stress distribution. FIG. 41c shows the
detailed commissural and the short bar attachment as well as the
circumference sealing area at the bottom portion of the pericardium
assembly. It is shown in the figures that bars 551, which are
relatively short, allow firm attachment of the top portion of the
commissural, slack portion in the middle, and a good sealing
surface at the bottom portion 556.
[0238] Reference is now made to FIGS. 42a and 42b illustrating an
isometric view of an implantable prosthetic valve in accordance
with yet another preferred embodiment of the present invention,
having a different commissural attachment. FIG. 42b depicts the
attachment in details. In the embodiment shown in FIG. 42a, similar
valve assembly is illustrated, while the short bar is arranged in a
manner that is similar to the structure shown in FIG. 28 and
described herein before. Relatively short bars 559 act as the
attachment means to the frame bar 558. Suture 557 attaches short
bars 559 to a member 558, the suture can be made from an elastic
material so that to add flexibility to the commissures and to
render the valve assembly the benefits already explained
herein.
[0239] Reference is now made to FIGS. 43a and 43b illustrating an
isometric view of an implantable prosthetic valve in accordance
with yet another preferred embodiment of the present invention.
FIG. 43a depicts commissures that are pre-sutured in a tapered
shape. The valve assembly shown in FIG. 43a comprises a frame 560,
pericardial leaflets 563, and attachment means 561. Pericardial
leaflets 563 are shown to be in an open state so as to establish an
open valve assembly while dashed lines 565 show the valve in a
closed sealed state. The attachment to the commissures can be
performed using one of the explained techniques. Specifically to
the embodiment shown in FIGS. 43a and 43b, the focus is on the
formation of a tapered valve in which the attachment means is in
the shape of long bars 561 that are attached to the pericardium in
an angular way in apposition to the parallel attachment. Attaching
the bars in an angular way when the pericardium is flattened will
create a tapered tube when built up to the three dimensional shape.
When the whole prosthetic valve is inflated by a balloon, the
pericardium leaflet, at the top circumference of the frame, is
stretched and the frame is expanded to the full diameter. After
deflating the balloon, the frame stays in its expended size but the
pericardial leaflets regains their pre-stretched shape. This
process creates a permanent clearance distance 562 between the
pericardial leaflets 563 and frame 560. This is of major importance
in the protection of the pericardium from abrading against the
frame.
[0240] Reference is now made to FIGS. 44a to 44c illustrating an
isometric view of an implantable prosthetic valve in accordance
with yet another preferred embodiment of the present invention,
with additional pieces of PET used for sealing and protecting the
pericardium. The illustrated implantable valve assembly resembles
the valve shown in FIG. 43, however, it is emphasized that in the
attachment of the pericardial leaflets 570 to frame 575, there is
use of PET. FIG. 44c shows in a cross-sectional view, the way the
PET is assembled to the pericardium and the frame in a manner that
protects the pericardium against wear. PET 571 and 572 are used for
connecting pericardial leaflets 570 to frame 575, while they are
assembled in between the leaflets and the frame. A suture 577
connects pericardium leaflet 570 in between two layers of PET,
while the inner layer of PET 572 is short and the outer layer is
longer. Bottom attachment suture 576, connects the three layers,
the leaflet and both PET layers to the flame and forms a strong
sealing line. An upper suture 578 connects the outer PET layer 571
to frame 575. When the valve assembly closes and the pericardial
leaflets come closer to each other at the top of the assembly,
there is a tendency of the bottom attachment to move and rotate
about an attachment point 577. Upper suture line 578 keeps the
outer PET layer tight and prevents a part of this rotational
movement, which can rapidly cause an abrasion failure.
[0241] FIGS. 45a to 45d illustrate an isometric view of an
implantable prosthetic valve in accordance with yet another
preferred embodiment of the present invention, having leaflets
sutured to a pre-shaped PET tube and optional leaflet-tube
attachments in details. A novel technique of mounting pericardial
leaflets 580 to a pre shaped PET tube 585 is shown. The tube is
shaped so as to have a folding 586 with substantially sinusoid
pattern 586 that is similar to the optimal connection line of valve
leaflets in the natural valve. This shape allows the pericardial
leaflets to be sutured to the interior of the PET tube. The
preferred suturing techniques are shown in the cross sectional
views of PET tubes in FIGS. 45b, 45c, and 45d. Generally, in order
to protect the pericardial leaflets from tearing, an additional
piece 583 of PET is added below the suture lines. Similar
variations are shown in FIGS. 45c and 45d.
[0242] Reference is now made to FIG. 46a illustrating an exploded
view of an implantable prosthetic valve assembly in accordance with
yet another preferred embodiment of the present invention, where
the leaflets are mounted on a pre-cut and pre-shaped tube and the
outlet of the valve is cut in a commissural shape. FIG. 46a is view
of the attachment. A pre-shaped PET tube 590 is cut to have
substantially sinusoidal shape 596 and then bent in order to
provide a suturing area. The pericardium leaflet 593 is pre-cut and
assembled to PET tube 590 by means of suturing 502. In this case as
well as in the former case, an additional protective layer of PET
or pericardium 594 is added. FIG. 46b is a cross-section of the
attachment detail after being tightened
[0243] FIGS. 47a to 47c illustrate a partial cross-sectional side
view of an inflating balloon in accordance with a preferred
embodiment of the present invention. The balloon is a part of an
implantable prosthetic valve delivery system. FIGS. 47b and 47c are
cross sectional upper views in the inflated and deflated positions,
respectively. The specially designed balloon shown in the figures
preferably comprises four inflating members, three substantially
identical and symmetrical sections 600 and a central section 602.
Pericardial leaflets 612 are positioned between sections 600 and
separate them. A frame 610 circles the inflating members and a
balloon shaft 619 that is positioned in the center of the delivery
system while a commissural connection 613 connects pericardial
leaflets 612 to frame 610. The inflated balloon sections 600 are
placed between frame 610 and pericardial leaflets 612 so that when
the inflating members are inflated, they push leaflets 612 toward
each other and frame 610 so as to establish a fully closed
position. This technique better preserves the leaflets since there
is no contact between the leaflets and the frame besides in the
commissural connection. The preservation of the leaflets is even
improved in times of inflation as well as after inflating the valve
and establishing a closed position. In FIG. 47a the fourth
inflating member of the balloon, central section 602 is clearly
shown. Through central section 602, the inlet 617 of the valve is
inflated while the inflated central section assures that the whole
valve is fully inflated to substantially round shape. FIG. 47c
shows the assembly in a crimped position. Frame 610 is crimped and
sections 600 are deflated. Pericardial leaflets 612 are also shown
in a crimped configuration.
[0244] FIGS. 48a and 48b illustrate a partial cross-sectional side
view and an upper cross sectional view of an inflating balloon in
accordance with another preferred embodiment of the present
invention. The inflating balloon comprises of a central inflating
balloon 620 and three protection sheets 622. In the lateral
cross-section shown in FIG. 48b, the parts of inflated assembly 625
are clearly shown, protection sheets 622 protects the pericardial
leaflets 624 from being pushed against the frame 625 when the
device is inflated. The advantage of this arrangement is in the
protection of the pericardial leaflets.
[0245] The preferred embodiments representing an implantable
prosthetic valve in accordance with the present invention are
relatively easy to manufacture as they are generally flat
throughout most of the production process and only at the final
stage of mounting the other elements of the valve assembly on the
support frame, a three dimensional form is established.
[0246] A typical size of an aortic prosthetic valve is from about
19 to about 25 mm in diameter. A maximal size of a catheter
inserted into the femoral artery should be no more than 8 mm in
diameter. The present invention introduces a device, which has the
ability to change its diameter from about 4 mm to about 25 mm.
Artificial valves are not new; however, artificial valves in
accordance with the present invention posses the ability to change
shape and size for the purpose of delivery and as such are novel.
These newly designed valves require new manufacturing methods and
technical inventions and improvements, some of which were described
herein.
[0247] As mentioned earlier, the material of which the valve is
made from can be either biological or artificial. In any case new
technologies are needed to create such a valve.
[0248] To attach the valve to the body, the blood vessels determine
the size during delivery, and the requirements for it to work
efficiently, there is a need to mount it on a collapsible
construction which can be crimped to a small size, be expanded to a
larger size, and be strong enough to act as a support for the valve
function. This construction, which is in somewhat similar to a
large "stent", can be made of different materials such as Nitinol,
biocompatible stainless steel, polymeric material or a combination
of all. Special requirement for the stent are a subject of some of
the embodiments discussed herein.
[0249] The mounting of the valve onto a collapsible stent is a new
field of problems. New solutions to this problem are described
herein.
[0250] Another major aspect of the design of the valve of the
present invention is the attachment to the body.
[0251] In the traditional procedure the valve is sutured in place
by a complicated suturing procedure. In the case of the
percutaneous procedure there is no direct access to the
implantation site therefore different attachment techniques are
needed.
[0252] Another new problem that is dealt herein is the delivery
procedure, which is new and unique. Positioning of the device in
the body in an accurate location and orientation requires special
marking and measuring methods of the device and surgical site as
was disclosed herein.
[0253] Artificial polymer valves require special treatment and
special conditions when kept on a shelf, as well as a special
sterilization procedure. One of the consequences of the shelf
treatment is the need to crimp the valve during the implantation
procedure. A series of devices and inventions to allow the crimping
procedure are disclosed herein.
[0254] It should be clear that the description of the embodiments
and attached Figures set forth in this specification serves only
for a better understanding of the invention, without limiting its
scope as covered by the following claims.
[0255] It should also be clear that a person skilled in the art,
after reading the present specification could make adjustments or
amendments to the attached Figures and above described embodiments
that would still be covered by the following claims.
* * * * *