Note: Descriptions are shown in the official language in which they were submitted.
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BIZIN(3 OBTORATOR FOR PR08T8ETIC AORTIC VALVEB
Field of the Invention
The present invention pertains generally to medical
devices and more particularly to an obturator apparatus
insertable into an aortic valve annulus of a human heart
following performance of a valvulotomy for the purpose of
determining the correct size of a prosthetic valve to be
surgically implanted therein.
Baoxaround of the Invention
Surgical valvulotomy and prosthetic valve
replacement has been performed in human beings for many
years. Most frequently, the procedures are utilized to
replace mitral or aortic valves in patients who suffer
from valvular heart disease.
In particular, surgical replacement of the aortic
valve is typically necessitated by a) obstruction (i.e.,
stenosis) of the aortic heart valve or b) leakage (i.e.,
regurgitation, incompetence or insufficiency) of blood
through the aortic valve. In some patients, symptoms of
both obstruction and leakage are present, this being
known as "mixed disease" or "combined lesions". Aortic
valvular heart disease may be caused by a number of
factors, including congenital deformations, infections,
degenerative calcification, and certain rheumatological
heart disorders.
Surgical replacement of the aortic valve is
typically performed under general anesthesia, with full
cardiopulmonary bypass. The leaflets of the endogenous
aortic valve are removed along with any calcified
surrounding tissue. This results in the formation of an
annular opening at the site of the endogenous aortic
valve. Thereafter, a mechanical or bioprosthetic aortic
valve is then selected and sutured into the annular valve
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opening, as a prosthetic replacement for the surgically-
removed endogenous valve. Examples of mechanical
prosthetic aortic valves which have heretofore been
utilized, include the Starr-Edwards'~ Silastic Ball Valve
(Baxter Healthcare Corporation, Edwards CVC Division,
17221 Red Hill Ave., P.O. Box 11150, Santa Ana,
California 92711-1150); the St. Jude Bileaflet Heart
Valve (St. Jude Medical, Inc., St. Paul, Minnesota) and
the Medtronic-Hall Tilting Disk Valve (Medtronic Inc.,
Minneapolis, Minnesota). Examples of bioprosthetic
aortic valves which have heretofore been utilized include
the Carpentier-Edwards~, PERIMOUNT" Pericardial
Bioprosthesis (Baxter Healthcare Corporation, Edwards CVS
Division, 17221 Red Hill Ave., P.O. Box 11150, Santa Ana,
California 92711-1150) as well as the Carpentier-Edwards~
Porcine Bioprosthesis (Baxter Healthcare Corporation,
Edwards CVC Division, 17221 Red Hill Ave., P.O. Box
11150, Santa Ana, California 92711-1150).
In general, these prosthetic aortic valves comprise
a cylindrical valve body having a blood flow passageway
extending longitudinally therethrough, and a suture ring
formed annularly thereabout. The suture ring comprises
suture penetrable material or a series of suture passage
apertures, to facilitate anastomosis of the suture ring
to the adjacent surgically-prepared aortic annulus.
Because of the tricuspid configuration of the endogenous
aortic valve, the natural aortic root has a non-planar,
multi-curvate configuration. To correspond to such
anatomical configuration of the natural aortic root, some
or all of the aortic prosthetic valve of the prior art
have utilized suture rings which are of a generally non-
planar, multi-curvate configuration.
The ultimate success of any aortic valve placement
procedure is dependant on a number of factors, including
the correct sizing and placement of the prosthetic aortic
valve. In this regard, it is common practice to utilize
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a sizing obturator to determine the correct size of
prosthetic valve for implantation. Such sizing
obturators typically comprise a series of different-sized
cylindrical members which are independently attachable to
a handle, and which are insertable into the surgically-
prepared valve annulus to determine the actual size of
the annular opening. Such sizing obturators may be
color-coded for size identification. Examples of aortic
and mitral valve sizing obturators of the prior art
include the True-Size"' Aortic Obturator-Model 1161 and
the True-Size"' Mitral Obturator-Model 1162, Baxter
Healthcare Corporation, Edwards CVS Division, 17221 Red
Hill Ave. , P.O. Box 1150, Santa Ana, California 92711-
1150.
One drawback associated with aortic valve sizing
obturators of the prior art is that such obturators
typically comprise a generally cylindrical obturator body
having a flat annular flange extending therearound. The
flat annular flange is typically advanced into abutment
with, but does not actually seat or nest within, the non-
planar, three-peaked anatomy of the natural aortic root,
which defines the superior aspect of the aortic annulus.
In view of the importance of ascertaining the
correct size and configuration of the prosthetic aortic
valve to be utilized, there exists a need in the art for
the development of a new sizing obturator device which
has a non-planar, multi-curvate flange configured to
directly seat or nest within the three-peaked normal
anatomy of the superior aspect of the annular, thereby
providing the surgeon with an accurate, preliminary
reading of the correct size and configuration of non-
planar, multi-curvate suture ring to be utilized.
Accordingly, a primary object of the present
invention is to provide a sizing obturator which has a
cylindrical body which may be inserted through the
annulus. and a flange member which is configured to be
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4
substantially complimentary to the configuration of the superior aspect of the
aortic annulus, within which a prosthetic valve is to be subsequently
implanted.
Another object of an aspect of the present invention is to provide such
s a sizing obturator whose cylindrical body has, disposed therein, a connector
member which is connectable to a handle usable during obturator placement.
Yet another object of the present invention is to provide methodology
employing the above-defined obturator in a plurality of sizes to thereby
accurately reflect aortic annulus size for subsequent prosthetic valve
implantation.
These and other objects of aspects of the present invention will
become apparent throughout the description of the invention which now
follows.
Summary of the Invention
15 In accordance with an aspect of the invention, a reusable aortic valve
sizing obturator apparatus comprising:
a cylindrical obturator body having a central axis, a top end, a bottom
end, and an outer surface;
said cylindrical obturator body having a first outer diameter;
2o a rigid annular flange member extending substantially radially outward
from said cylindrical obturator body, said flange member having an upper
surface, an undersurface, and a second outer diameter, said second outer
diameter being larger than said first outer diameter said cylindrical
obturator
body and said flange member being formed of materials suitable for
2s sterilization in an autoclave; and,
the undersurface of said flange member having, in a circumferential
direction about said central axis, a non-planar, multi-curvate configuration.
In accordance with another aspect of the invention, a method for sizing
an aortic valve annulus for subsequent placement therein of a prosthetic
so aortic valve, a superior aspect of the annulus having a natural aortic root
shape, the method comprises the steps of:
a) providing a reusable aortic valve sizing obturator comprising:
(i) a cylindrical obturator body having a top end, a bottom
end, an outer surface and a first outer diameter about a central axis;
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(ii) a rigid flange member extending substantially radially
outward from said cylindrical obturator body, said flange member
having an upper surface, an undersurface, and a second outer
diameter, said second outer diameter being larger than said first outer
5 diameter said cylindrical obturator body and said flange member being
formed of materials suit-able for sterilization in an autoclave;
(iii) the undersurface of said flange member having, in a
circumferential direction about said central axis, a non-planar, multi-
curvate configuration;
b) sizing said annulus by inserting said obturator into the
aorta so that said cylindrical body fits within said aortic valve annulus
and said flange member undersurface contacts the superior aspect of
the aortic annulus; and
c) rotating said obturator about said central axis and further
~5 advancing said obturator so that said flange member undersurface
conforms to the shape of the natural aortic root.
In accordance with a further aspect of the invention, a reusable aortic
heart valve sizing obturator of the type comprises a substantially cylindrical
obturator body having a first diameter and a rigid annular flange which
2o extends substantially outward from said cylindrical obturator body, said
flange
having an undersurface which abuts against a superior aspect of the aortic
annulus when said flange is positioned supra-annularly such that the
cylindrical obturator body extends through the aortic annulus, said
cylindrical
obturator body and said flange being formed of materials suitable for
25 sterilization in an autoclave, the improvement comprises:
a flange undersurface having, in a circumferential direction, a
non-planar, multi-curvate configuration to conform to the shape of the
superior aspect of the aortic annulus, thereby allowing said flange to
nest against the superior aspect of the aortic annulus with the
3o cylindrical obturator body.
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5a
In accordance with another aspect of the invention, a kit for
determining the size of a prosthetic aortic heart valve to be implanted into a
surgically-prepared aortic annulus within a mammalian heart, said kit
comprising a plurality of reusable sizing obturators each have:
s a substantially cylindrical obturator body defining an outer surface
having a first outer diameter; and,
a rigid annular flange extending radially outward from said obturator
body to a second outer diameter larger than said first outer diameter, said
cylindrical obturator body and said flange being formed of materials suitable
for sterilization in an autoclave, said flange having an upper surface and an
undersurface with a circumferentially multi-curvate configuration, wherein at
least the first diameter of one of said sizing obturators is different than
the first
diameter of another of said sizing obturators.
In accordance with a further aspect of the invention, an aortic valve
~s sizing obturator apparatus comprises:
a hollow, substantially cylindrical obturator body defining an outer
surface having a first outer diameter;
an annular flange extending radially outward from said obturator body
to a second outer diameter larger than said first outer diameter, said flange
2o having an upper surface and an undersurface with a circumferentially multi-
curvate configuration having blunt peaks with arcuate depressions extending
between said peaks; and
a handle connector apparatus rigidly connected to said obturator body
whereby a separate handle member may be attached to said obturator
25 apparatus, said handle connector apparatus comprising a threaded member
longitudinally oriented within the hollow cylindrical
obturator body for rotatably coupling with a handle member, the
threaded member being rigidly affixed to the cylindrical obturator body with
radial strut members at locations corresponding to the blunt peaks on the
3o flange member.
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5b
Brief Description of the Drawings
Figure 1 is top perspective view of a preferred aortic valve sizing
obturator of the present invention.
Figure 2 is a top plan view of the preferred aortic valve sizing obturator
of Figure 1.
Figure 3 is a side elevational view of the preferred aortic valve sizing
obturator of Figure 1.
Figure 4 is a cross sectional view through line 4 - 4 of Figure 2.
Figure 5 is a cross sectional view through line 5 - 5
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of Figure 2.
Figure 6a is a perspective view of a prior art
handle member which may be utilized in conjunction with
the preferred aortic valve sizing obturator of the
present invention.
Figure 6b is a perspective view-of an alternative,
bendable, handle member which may be utilized in
conjunction with the aortic valve sizing obturator of the
present invention.
Figure 7 is a perspective schematic view of a
portion of a human heart, showing the manner in which the
preferred aortic valve sizing obturator of the present
invention is inserted into the surgically-prepared aortic
annulus.
Figure 7a is an enlarged elevational view of a
portion of Figure 7.
Detailed Descri~tioa of the Preferred Embodiment
The following detailed description and the
accompanying drawings are provided for the purpose of
describing and illustrating a presently preferred
embodiment of the invention only, and are not intended to
limit the scope of the invention in any way.
With reference to the drawings, the preferred aortic
valve sizing obturator 10 of the present invention
comprises a cylindrical obturator body 12 having an outer
surface 14 and an inner surface 16, and a non-planar,
multi-curvate annular flange 18 extending outwardly about
one end of the cylindrical obturator body 12. The non
planar, multi-curvate annular flange 18 has an upper
surface 20, and a lower surface 22. (As used in this
patent application, the term "multi-curvate" means having
more than one curve formed therein.)
The end of the cylindrical obturator body 12 upon
which the non-planar, multi-curvate flange 18 is
positioned, and the configuration of the non-planar,
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multi-curvate flange 18 itself, are characterized by the
presence of three equally-spaced-apart blunt peaks 24a,
24b, 24c having three generally arcuate depressions 26a,
26b, 26c extending therebetween, as shown.
Three (3) radial strut members 28a, 28b, 28c extend
inwardly from the inner surface 16 of the cylindrical
obturator body 12 at locations which are immediately
below each of the discrete blunt peaks 24a, 24b, 24c
formed in the non-planar, multi-curvate flange 18. A
l0 cylindrical inner member 30 is positioned coaxially
within the central bore 32 of the cylindrical obturator
body 12, and is supported and held in fixed position by
the strut members 28a, 28b, 28c. A hollow inner bore 34
extends longitudinally through the inner cylindrical
member 30, and internal threads 36 are formed on the
inner surface of such longitudinal bore 34.
A single longitudinal axis LA as illustrated in
Figure 4 is projectable longitudinally through the
cylindrical obturator body 12, such that the obturator
body 12 and inner cylindrical member 30 are coaxially
disposed about such common longitudinal axis LA.
Figure 6a-6b show two prior art stainless steel
handles which may be utilized in conjunction with the
preferred aortic valve sizing obturator shown in Figures
1-5. Specifically, Figure 6a shows a reusable handle
comprising an elongate rigid handle member 40 having an
externally threaded distal projection 42 extending from
the distal end thereof. The externally threaded
projection 42 is insertable into the upper end of the
bore 34 of the inner cylindrical member 30 of the
preferred aortic valve sizing obturator 10 of the present
invention such that the external threads of projection 42
may be rotatably engaged with the internal threads 36
formed within the bore 34 of the inner cylindrical member
30, thereby attaching the elongate handle member 40 to
the aortic valve sizing obturator 10. The particular
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handle shown in Figure 6a has been commercially available
as Handle Model 1108, Baxter Healthcare Corporation,
Edwards CVC Division, 17221 Red Hill Ave., P.O. Box
11150, Santa Ana, California 92711-1150.
Figure 6b shows an alternative handle which
comprises a segmented rigid handle member 40a having a
bendable segment 46 disposed therewithin, and an
externally threaded distal projection 42a extending from
the distal end thereof. A flanged bushing 44 is formed
proximal to the externally threaded distal portion 42a,
as shown. The bendable segment 46 of this handle may be
manually bent or preformed by the surgeon to a desired
configuration to facilitate insertion and positioning of
the aortic valve sizing obturator 10. The particular
handle shown in Figure 6b has been commercially available
as Handle Model 1111, Baxter Healthcare Corporation
Edwards CVC Division, 17221 Red Hill Ave., P.O. Box
11150, Santa Ana, California 92711-1150.
The aortic valve sizing obturator 10 may be formed
of any suitable material including rigid, autoclavable
thermoplastic material such as polysulfonate. The
obturators 10 will typically be provided in a kit
consisting of a series of different-sized obturators 10,
corresponding to the available sizes of the particular
prosthetic heart valves for which the obturator 10 is to
be employed. For example, the following table shows
examples of specific coiaponent dimensions (in
millimeters) of standard, commercially available sizes of
the Carpentier-Edwards~ PERIMOUNT"' Pericardial Aortic
Bioprosthesis referred to hereabove:
Mounting Diameter (Annulus) 19 21 23 25 27 29
Internal Diameter (Stent I.D.) 18 20 22 24 26 28
Profile Height 13 14 15 16 17 18
External Sewing Ring Diameter 28 31 33 35 38 40
When the sizing obturator 10 of the present invention is
to be used for determining the correct size of the Model
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2700 Aortic Bioprosthesis to be employed, the
manufacturer will typically provide a kit having a series
of different-sized obturators 10, which correspond
directly to the available sizes of the Model 2700 Aortic
Valvular Prosthesis. In this regard, if an obturator 10
having a mounting diameter (i.e., the diameter of the
outer surface 14 of the cylindrical obturator body 12) of
19 is found to provide the best fit within the
surgically-prepared valve annulus, a Model 2700
prosthetic valve having a mounting diameter of 19 will
typically be selected. Also, because the sizing
obturator 10 of the present invention is provided with a
non-planar, multi-curvate flange 18, such flange may be
directly nested or seated within the surgically-prepared
natural valve annulus to provide a direct and precise
indication of the correct external sewing ring diameter
desired.
It will be appreciated that, in most aortic valve
replacement surgeries, the prosthetic valve is implanted
in a supra-annular position wherein the suture ring of
the prosthetic valve is positioned superior to the
surgically-prepared valve annulus. Alternatively,
however, it may sometimes be desirable to implant the
prosthetic valve in an intra-annular position, wherein
the entire suture ring of the prosthetic valve is
positioned within the surgically-prepared valve annulus
and an everting mattress suture technique is employed to
anastomose the prosthetic valve in such intra-annular
position. In this regard, when it is desired to utilize
the typical supra-annular positioning of the prosthetic
valve, the sizing obturator 10 will be inserted such that
the non-planar, multi-curvate flange 18 is nested or
seated in a supra-annular position which is analogous to
the intended positioning of the suturing ring of the
prosthetic valve. Alternatively, however, if it is
intended to implant the prosthetic valve in an intra-
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annular position, the sizing obturator 10 of the present
invention will be initially placed such that the non-
planar, multi-curvate annular flange 18 is located in the
desired intra-annular position.
5 Figures 7-7a provide a schematic illustration of the
typical manner in which the aortic valve sizing obturator
10 of the present invention may be utilized to determine
the correct prosthetic valve size to be used for supra-
annular implantation in a human heart. In the showing of
10 the human heart provided in Figure 7, the major
anatomical structures are labeled accordingly to the
following legend:
A = Aorta
AA = Aortic Annulus
M = Myocardium
IVS = Interventricular Septum
RV = Right Ventricle
RA = Right Atrium
LV = Left Ventricle
SVC = Superior Vena Cava
As shown, a handle such as that shown in Figure 6b
is initially inserted and engaged into the upper end of
the hollow bore 34 of the sizing obturator 10, and the
threaded distal projection 42a of the handle is rotatably
advanced such that its external threads will rotatably
engage the internal threads 36 formed within the bore 34
of the obturator 10. In this manner, the handle of the
type shown in Figure 6b is firmly attached to the
obturator 10, and extends in a longitudinally coaxial
fashion from the upper end of the obturator 10, as shown.
The diseased or damaged aortic valve leaf lets, and
all associated structures deemed necessary, are
surgically removed. The surgeon may also remove any
calcium from the valve annulus, to ensure proper seating
of the suture ring of the prosthetic valve.
After the aortic valve annulus has been surgically
prepared, the aortic valve sizing obturator 10 of the
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present invention will be inserted such that the
cylindrical obturator body 12 passes downwardly through
the surgically-prepared valve annulus with little
resistance. The obturator 10 is then rotatably
reoriented and further advanced until the undersurface 22
of the non-planar, multi-curvate flange becomes nested or
seated within the non-planar, multi-curvate anatomical
structure of the natural aortic root. In this manner,
the surgeon may visually verify that the diameter of the
cylindrical obturator body 12 and non-planar, multi-
curvate annular flange 18 are correct for that particular
patient. Thereafter, the surgeon may select a prosthetic
aortic valve which has a mounting (annulus) diameter and
external sewing ring diameter the same as that of the
obturator 10 which was found to correctly fit within the
patient's aortic valve annulus. Thereafter, the
obturator 10 and accompanying handle may be extracted and
removed, and the selected prosthetic aortic valve may be
sutured into place. Following use, the handle may be
2 0 rotatably detached and removed from the obturator 10 , and
both the stainless steel handle and the molded plastic
obturator may be autoclaved or otherwise sterilized for
subsequent reuse.
It will be appreciated that the present invention
has been described hereabove with reference to certain
presently preferred embodiments only, and no effort has
been made to exhaustively describe all possible
embodiments in which the invention may take physical
form. It will be appreciated by those skilled in the art
that various addition, deletions, modifications and
alterations may be made to the above-described embodiment
without departing from the intended spirit and scope of
the present invention. Accordingly, it is intended that
all such additions, deletions, modifications and
alterations be included within the scope of the following
claims.
