United States Patent [19]
`Bédard
`
`(page é'i‘véiiabte ‘(30123,’
`[54] CARDIAC VALVE PROSTHESIS HOLDER
`
`[75] Inventor:
`[73] Assignee:
`
`Pierre Bédard, Nepean, Canada
`
`Molrose Management, Ltd., Ontario,
`
`'
`
`Canada
`
`[21] Appl. No.: 457,514
`
`[22] Filed:
`
`Jan. 13, 1983
`
`[51] Int. Cl.3 .............................................. .. A61F 1/22
`
`[52]. U.S. Cl. . . . . . . . . . . . . . . . .
`
`. . . . . . . . .. 3/1.5; 128/334 R
`
`[58] Field of Search .................. .. 3/l.5, 1; 128/334 R,
`128/334 C
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`3,503,079 3/1970 Smith ..................................... .. 3/ 1.5
`3,574,865 4/1971 Hamaker
`3/l.5
`3,996,623 12/1976 Kaster ..... ..
`3/l.5
`3,997,923 12/1976 Possis ..................................... .. 3/l.5
`
`I [11] Patent Number:
`[45] Date of Patent:
`
`4,506,394
`Mar. 26, 1985
`
`FOREIGN PATENT DOCUMENTS
`
`1180087 10/1964 Fed. Rep. of Germany ......... .. 3/1.5
`Primary Examiner—Ronald L. Frinks
`[57]
`ABSTRACT
`An implantable device which is suited for implantation
`into a human or animal heart for receiving and remov
`ably holding a valve prosthesis is described. The device
`comprises a ring structure which is adapted to be ?xed’
`to the tissue around the ori?ce of a heart valve after
`excision of the diseased or damaged natural valve has
`been effected. In use, the ring structure is ?xed in place
`and then the appropriate valve prosthesis is attached to
`the ring. When the valve prosthesis fails and has to be
`replaced with a new prosthesis, the damaged prosthesis
`can be‘detached from the ring allowing a replacement
`prosthesis to be ?xed to the ring without affecting the
`connection between ring structure and tissue.
`
`6 Claims, 16 Drawing Figures
`
`NORRED EXHIBIT 2103 - Page 1
`Medtronic, Inc., Medtronic Vascular, Inc.,
`& Medtronic Corevalve, LLC
`v. Troy R. Norred, M.D.
`Case IPR2014-00110
`
`

`

`U.S. Patent Mal-.26, 1985
`
`Sheetl§f3 ‘ 4,506,394’
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`FIG. 3.
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`NORRED EXHIBIT 2103 - Page 2
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`vU.S. Patent Mar.26, 1985
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`‘ Shéet20‘f3
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`4,506,394v
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`NORRED EXHIBIT 2103 - Page 3
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`VU.S. Patent Mar. 26, 1985
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`‘Sheet3of3
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`NORRED EXHIBIT 2103 - Page 4
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`1
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`4,506,394
`
`CARDIAC VALVE PROSTHESIS HOLDER
`
`This invention relates to a device adapted to be im
`planted into a human or animal heart for receiving and
`removably holding in place a valve prosthesis. More
`particularly, the invention relates to a ring arrangement
`adapted to be attached to tissue surrounding a diseased
`or damaged cardiac valve to facilitate insertion and
`replacement of a valve prosthesis.
`An implantable device of this kind should be durable
`and last for many years while exposed to body ?uids
`and wear caused by movement of the valve prosthesis
`relative to the ring in response to the constantly chang
`ing pressure exerted on the valve. Furthermore, such a
`ring arrangement requires provisions permitting the
`ring to be securely ?xed to the tissue surrounding the
`valve ori?ce. In use, the ring should allow free flow
`through the valve and any obstruction of the valve
`ori?ce should be kept to a minimum such as by using a
`ring arrangement with an ori?ce substantially identical
`to that of the valve and the valve prosthesis. A ring of
`this kind further requires provisions for securing a valve
`prosthesis to the ring in such a way that the prosthesis
`can easily be replaced as required, but does not become
`disconnected unless removed by a surgeon. Moreover,
`the ring arrangement should be made of or covered
`with materials which are inert and also substantially
`non-thrombogenic.
`Valve prostheses have been used to replace various
`diseased or damaged natural valves. Among the four
`heart valves, the aortic valve, the mitral valve, the pul
`monic valve and the tricuspid valve, the aortic and
`mitral valves are most frequently replaced.
`The mitral valve controls the ?ow of blood between
`the left atrium and the left ventricle and the aortic valve
`controls the blood flow from the left ventricle into the
`aorta.
`Generally the known cardiac valve prostheses are
`either bioprostheses and mechanical prostheses. The
`bioprostheses are generally made of a suitable animal
`tissue on a metal or plastic frame while the mechanical
`prostheses are made entirely of metal and/or plastic
`material.
`The valve prostheses are adapted to be stitched to the
`tissue surrounding the diseased valve that is being re
`placed. To this effect the valve prosthesis frame in
`cludes a generally circular structure, the valve seat,
`which is mostly made of metal or plastic and which is
`usually provided with a woven or knitted fabric to
`facilitate suturing. The fabric surrounding the circular
`structure and often also other parts of the valve frame is
`mostly called a sewing ring or skirt.
`Heart valve prostheses are subject to severe wear and
`often have to be replaced after a relatively short time.
`Other factors which necessitate replacement of an im
`planted valve prosthesis are the patient’s adverse reac
`tion to the implant, physical or chemical changes in the
`components of the valve, particularly those compo
`nents which are of biological origin, or other material
`failure.
`Every time replacement of an implanted prosthesis is
`effected, the sutures holding the prosthesis in place have
`to be removed and the new valve prosthesis has to be
`stitched to the same tissue area as the previous one. In
`this way the tissue surrounding the valve ori?ce be
`comes perforated and scarred and with each replace
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`ment operation it becomes progressively more dif?cult
`to secure the implant to the tissue.
`In an effort to test and compare the performance of
`various valve prostheses in vivo Wexler et al (J. Cardi
`ovasc. Surg. (Torino) 11,236-38, 1970) proposes the
`temporary implantation of an elastic sewing ring into
`the heart of a laboratory animal in which the various
`prostheses are to be tested. Wexler’s elastic sewing ring
`is made of rubber bands covered with fabric and pro
`vided with four wires which are looped around the
`rubber bands and extend through the fabric to facilitate
`gripping of the sewing ring. The sewing ring is placed
`around a valve prosthesis and inserted into the valve
`opening. The sewing ring is stitched to the tissue and in
`this way holds in place the prosthesis to be tested. When
`the testing of the thus implanted valve prosthesis is
`completed, generally after about 1 hour, the sewing ring
`is expanded to release the ?rst valve prosthesis and
`allow insertion of the second. In this way the rubber
`sewing ring allows rapid replacement of the valve pros
`thesis. Of course, Wexler’s rubber sewing ring is de
`signed only for very short term use in animal tests. The
`ring could not safely be implanted for any long term
`use, since the material is subject to fairly rapid deterio
`ration and since, even prior to any noticeable deteriora
`tion, the rubber ring could easily be accidentally discon
`nected from the valve prosthesis as a result of the pres
`sure differentials encountered in the heart. Moreover
`the protruding wires are likely to cause damage to the
`surrounding tissue.
`Accordingly, the present invention provides an im
`plantable device such as a ring arrangement which is
`suited for implantation into a human or animal heart for
`receiving a valve prosthesis. The ring is adapted to be
`?xed to the tissue around the ori?ce of the heart valve
`after excision of the diseased or damaged natural valve
`has been effected. Once the ring is ?xed in place the
`appropriate valve prosthesis can be attached'to the ring.
`When the valve prosthesis fails and has to be replaced
`with a new prosthesis, the damaged prosthesis is de
`tached from the ring and the new replacement prosthe
`sis is ?xed to the ring. Since the connection between the
`ring and the tissue is not affected by this replacement of
`valve prostheses no additional perforation of the tissue
`takes place. This has the advantage that the operation is
`less traumatic for the patient and that the new valve
`prosthesis is as securely attached to the tissue as the old
`one was, even if over the years the valve prosthesis has
`to be replaced several times.
`As the life expectancy of most bioprostheses is pres
`ently not yet known, surgeons often hesitate to use a
`bioprosthesis due to the uncertainty as to how often it
`will have to be replaced. Mechanical prostheses are
`often used instead, even though bioprostheses have
`some intrinsic advantages over the mechanical prosthe
`ses. For example, vbioprostheses are generally less
`thrombogenic than mechanical prostheses which means
`that, while patients with mechanical valve prostheses
`have to be maintained on anticoagulants, patients with a
`bioprosthesis do not generally require long term antico
`agulant therapy. As implantation of a ring according to
`the invention considerably facilitates replacement of
`valve prostheses, whether mechanical or bioprostheses,
`the ring allows surgeons to use bioprostheses more -
`freely.
`Use of the ring arrangement according to the inven
`tion also reduces the risk of perivalvular leaks develop
`ing, i.e. of blood passing between the tissue and the
`
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`prosthesis when the valve is closed. The reason for this
`the ring relatively easily without affecting the attach
`is that, once the ring is ?xed to the tissue, the connection
`ment of the ring to the tissue.
`between ring and tissue can be checked and, if neces
`The valve prosthesis may be connected to the ring in
`sary, repaired before the valve prosthesis is inserted and
`various ways, in most cases, however, the skirt of the
`attached to the ring.
`valve prosthesis is used to attach the prosthesis to the
`The ring arrangement according to the invention
`ring. To this effect the skirt is advantageously made of
`may be used in connection with most types of cardiac
`slightly stretchable material and suf?ciently long that it
`valve prostheses, whether mechanical or bioprosthesis.
`can be pulled over at least part of the outer periphery of
`Only minor changes to the prosthesis may be necessary
`the ring. In order to securely fasten the valve prosthesis
`to allow secure and easy attachment of the respective
`to the ring one of the following provisions may be
`prosthesis to the ring. Such minor changes would not
`made:
`alter the basic concept of the prostheses. As long as the
`(a) The ring may be provided at its periphery with a
`shape of the annular seat and sewing ring of a prosthesis
`groove large enough to accommodate the skirt of the
`is not signi?cantly altered, the prosthesis can be at
`prosthesis and an appropriate size suturing thread. The
`tached to the inventive ring arrangement.
`latter is passed over the skirt around the periphery of
`The ring arrangement may have any convenient
`the ring and tightened against the ring. Alternatively.
`shape which allows effective securement of the ring to
`the skirt of the prosthesis may already be provided with
`the tissue and which allows the valve prosthesis to be
`a thread so that the skirt merely has to be pulled over
`conveniently and securely attached to the ring as well
`the ring until the thread can be tightened in the groove.
`as removed from the ring.
`(b) The periphery of the ring may be provided with a
`The ring arrangement according to the invention is
`number of hooks so that, when the skirt is pulled over
`made of inert material such as certain metals and plastic
`the ring, the hooks engage the skirt. Generally the skirt
`materials and/or certain fabrics which do not react with
`is additionally tied below the hooks. The tying thread
`body fluids to which the ring is exposed and are, in
`may be held in place by the hooks only or additionally
`particular, as little thrombogenic as possible. To further
`by a groove. Either way the prosthesis can be securely
`reduce any slight thrombogenic effect the ring material
`attached and detached in a relatively short time.
`may have, the area of the ring which, in use, is in
`(c) The periphery of the ring may be provided with
`contact with the blood stream may be covered with any
`eyelets, fabric or other means which allow stitching ot'
`kind of non-thrombogenic fabric. In most cases it is
`the valve prosthesis to the ring in such a way that the
`advantageous to use a ring which retains its shape such
`stitches can be removed without affecting the sutures
`as a ring made of slightly resilient, but substantially rigid
`connecting the ring with the tissue.
`material. §uch a ring is generally easier to handle than a
`((1) In addition to any of the aforementioned provi
`soft ring and allows the back pressure exerted on the
`sions the surface of the ring which, in use, contacts the
`valve prosthesis, during diastole in the case of the aortic
`valve prosthesis may have a radial groove which coop
`valve prosthesis, to bear not only on the stitches con
`erates with a radial rib on the valve seat to reduce
`necting the ring to the tissue but also on the larger area
`movement of the valve prosthesis relative to the ring.
`of tissue on which the ring is supported.
`The connections between valve prosthesis and ring
`In order that the ring can be securely ?xed to the
`may also be effected in several other ways.
`tissue surrounding the valve ori?ce, one of the follow
`(e) The ring and valve seat of the prosthesis may be
`ing provisions may be made: '
`provided with an appropriate groove and rib to effect a
`(a) The ring may be partially or completely covered
`snap-in connection. Such a connection requires that
`with a knit or other fabric which facilitates suturing of
`either ring or valve seat are made of a suf?ciently resil
`the ring to the tissue, either with continuous or inter
`rupted stitches.
`ient material.
`(f) The ring and valve seat may be provided with
`(b) The ring may be provided around its periphery
`complementary screw threads. The prosthesis may be
`with eyelets which facilitate attachment of the ring with
`screwed either to the top of the ring, such as by provi
`sutures.
`(c) The ring may be provided with openings extend
`sion of a threaded radial groove in the ring, or into the
`ing substantially in axial direction through the ring
`ori?ce of the ring. In the latter case the diameter of the
`allowing suturing thread to be passed through.
`ori?ce of the ring and at the same time the valve ori?ce
`(d) The ring may be provided at its periphery with a
`is reduced and for this reason such a connection is only
`plurality of hook-like clamping extensions which permit
`suitable for replacement of valves which have a rela
`tively large ori?ce.
`clamping of the ring to the tissue.
`(g) The ring and valve seat may be provided with
`When sutures are used to ?x the ring arrangement to
`the tissue, it is important that the sutures are protected
`complementary hooks and retainers which engage
`from wear due to the slight movement of the valve
`when twisted relative to each other by a fraction of a
`prosthesis relative to the ring. In cases when sutures are
`turn.
`being passed through openings in the ring, it is desirable
`(h) In cases when hook-like clamping extensions are
`that the ring be provided with grooves for the thread,
`attached to the periphery of the seat of the valve pros
`particularly on the surface(s) of the ring which, in use,
`thesis the ring may be provided with fabric which per
`are in contact with the valve prosthesis.
`mits clamping of the prosthesis to the ring, or, alterna
`With regard to the connection between the ring ar
`tively, the ring may be made of fabric, fabric pad or the
`rangement according to the invention and the valve
`like.
`prosthesis it is important that, on the one hand, the
`(i) The valve seat can be provided with suitable screw
`valve prosthesis is attached to the ring suf?ciently se
`holes which correspond to screw holes in the ring.
`curely that accidental disconnection of the prosthesis is
`Thus, suitable screws can be put through the two sets of
`substantially prevented, while, on the other hand, the
`screw holes to attach the valve seat to the ring ?rmly.
`valve prosthesis can, when necessary, be detached from
`The screws preferably cannot be removed completely
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`NORRED EXHIBIT 2103 - Page 6
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`4,506,394
`5
`from the holes of the valve seat so that they will not
`become separated from the apparatus.
`For best results the skirt of the valve prosthesis may
`be pulled over connections (e) to (g) and (i) and stitched
`or tied to the ring. This additonal measure helps to
`prevent accidental disconnection between prosthesis
`and ring. It also generally avoids possible growth of
`tissue into the dead spaces in such connections and
`thereby minimizes difficulties in disconnecting the pros
`thesis from the ring after several years.
`To further ensure that the connection between ring
`and tissue is not accidentally severed at the time when
`the valve prosthesis is removed from the ring, a ?ange
`or the like may be connected to the periphery of the
`ring. The ?ange is intended to prevent the scalpel from
`penetrating along the periphery of the ring to the su
`tures holding the ring in place at the time when the
`thread and skirt are cut to remove the prosthesis.
`The present invention will now be described in more
`detail by way of example only and with reference to the
`accompanying drawings.
`FIGS. 1 to 9 illustrate embodiments of the invention
`adapted to receive an aortic valve prosthesis:
`FIG. 1 is a partial cross section of one embodiment of
`the invention;
`FIG. 2 is a partial cross section of a second embodi
`ment of the invention;
`FIG. 3 is a top plan view of the embodiment of FIG.
`
`20
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`or slightly wider than the valve seat and may be about
`2 mm wide. The inner surface 14 of the ring is smooth
`so that, when implanted, the ring forms a continuation
`of the annular valve seat and causes a minimum in dis
`turbance in the blood ?ow.
`A ?ange 20 is integrally connected with the ring on
`its outer surface. The ?ange may extend slightly up
`wardly as in FIGS. 1, 2 and 4 or may extend in radial
`outward direction as in FIG. 5.
`The radially outer surface of the ring 10 is further
`provided with a plurality of hooks 22 which are evenly
`spaced around the upper periphery of the ring and
`which in the illustrated embodiments are integral with
`the ring. The distance between the hooks shown in
`FIG. 3 is about 5 mm, but the hooks may also be ar
`ranged closer together or spaced further apart. The
`hooks can extend in radially outward direction as in
`FIGS. 1, 2 and 5 or be bent downward towards ?ange
`20 as in FIG. 4. Either way the ?ange extends beyond
`the hooks in radial direction.
`The rings illustrated in FIGS. 1 to 4 are each pro
`vided with a knit fabric 25 which in the illustrated em
`bodiments is either arranged to cover inner surface 14
`and lower surface 16 or substantially only lower surface
`16. The fabric or portion of the fabric which extends
`over lower surface 16 may be padded as in FIGS. 1, 2
`and 4 and it may extend over the ring only or over the
`ring and the ?ange. Upper surface 12 of the ring may
`also be covered with fabric.
`FIG. 6 illustrates the securement of a valve seat 30 of
`an aortic valve prosthesis on a ring arrangement ac
`cording to the invention. Skirt 31 of the prosthesis is
`pulled down over hooks 22 of ring 10 and tied to the
`ring with a suturing thread 32. Valve seat 33 shown in
`FIG. 7 is provided with a rib 34 which cooperates with
`groove 2 in ring 10. Skirt 35 of the prosthesis shown in
`FIG. 7 is provided at its lower end with a suturing
`thread 36 to facilitate tying of the skirt around the ring.
`Skirt 37 of the prosthesis shown in FIG. 8 is also pro
`vided with a suturing thread 36, but the skirt 37 is
`longer and extends beyond the thread so that a loose
`portion of the skirt substantially covers the upwardly
`facing side of ?ange 20.
`The illustrated ring arrangements are implanted into
`the aorta in such a way that the valve seat of an aortic
`valve prosthesis is positioned on the upper surface 12 of
`the respective ring and is attached to the ring as shown
`schematically in FIG. 9.
`FIGS. 10 to 15 illustrate ring arrangements adapted
`to receive a mitral or tricuspid valve prosthesis. Ring
`100 is similar to ring 10 in FIGS. 1 to 9 except that it is
`not as wide in radial direction. The embodiments shown
`in FIGS. 10 to 12 are each provided with a ?ange 20, a
`plurality of hooks 22 and a knit fabric cover 250. As in
`the case of the aortic valve the fabric or portion of
`fabric extending over the lower surface 160 of the ring
`may be padded and may extend over the ring only or
`over the ring and the ?ange. The upper surface of the
`ring may also be covered with fabric.
`FIGS. 13 and 14 each illustrate possible connections
`between a valve seat of a mitral valve prosthesis to a
`ring according to the invention. Skirts 31 and 35 of the
`prostheses 300 and 301 are pulled over a respective ring
`100 and over hooks 22 and tied to the ring. The illus
`trated ring arrangements for mitral valve prostheses are
`implanted into the left atrium in such a way that the
`prosthesis is positioned in the ori?ce of the ring and may
`be attached to the ring as shown in FIG. 15.
`
`NORRED EXHIBIT 2103 - Page 7
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`1;
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`FIG. 4 is a partial cross section of a third embodiment
`of the invention;
`FIG. 5 is a partial cross section of a fourth embodi
`ment of the invention;
`FIG. 6 illustrates in partial cross section the connec
`tion between the valve seat of an aortic valve prosthesis
`and the embodiment of FIG. 1;
`FIG. 7 illustrates in partial cross section the connec
`tion between the valve seat of a second aortic valve
`prosthesis and the embodiment of FIG. 2;
`FIG. 8 illustrates in partial cross section the connec
`tion between the valve seat of a third aortic valve pros
`thesis and a ?fth embodiment of the invention;
`FIG. 9 shows a schematic cross section of an aortic
`valve prosthesis connected to the embodiment of FIG.
`1;
`FIGS. 10 to 15 illustrate embodiments of the inven
`tion adapted to receive a mitral valve prosthesis;
`FIG. 10 illustrates a partial cross section of a sixth
`embodiment of the invention;
`FIG. 11 illustrates a partial cross section of a seventh
`embodiment of the invention;
`FIG. 12 illustrates a partial cross section of a eighth
`embodiment of the invention;
`FIG. 13 illustrates in partial cross section the connec
`tion between the valve seat of a mitral valve prosthesis
`and the embodiment of FIG. 10;
`FIG. 14 illustrates in partial cross section the connec
`tion between a second mitral valve prosthesis and the
`embodiment of FIG. 12;
`FIG. 15 shows a schematic cross section of a mitral
`valve prosthesis connected to the embodiment of FIG.
`11; and
`FIG. 16 is a bottom view of the skirt of a valve pros
`thesis shown in FIGS. 7 and 15.
`FIGS. 1 to 9 illustrate ring arrangements adapted to
`receive an aortic valve prosthesis. Ring 10 has a ?at
`upper surface 12 on which the annular seat of the aorta
`valve prosthesis can be placed. The surface is equal to
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`FIG. 16 illustrates the skirt of a valve prosthesis 302
`when the skirt is modi?ed to include a suturing thread
`as indicated in FIGS. 7 and 15. The thread 36 passes
`through the skirt with the ends of the thread hanging
`loosely from the skirt. To facilitate tightening of the
`skirt the thread is passed to the outside of the skirt in
`two places.
`The surface portions of the valve prostheses which,
`in use, are in close contact with the respective ring
`arrangement may be covered with fabric or the like as
`illustrated in FIGS. 6, l4 and 15 or may not be covered
`as shown in FIGS. 7, 8, 9 and 13.
`When a heart valve of a patient is diseased and has to
`be replaced the valve is removed in the known manner.
`The size of the valve ori?ce and the most suitable loca
`tion for implanting of the prosthesis is assessed by inser
`tion of a suitable obturator. The appropriate size and
`type of valve prosthesis and ring arrangement accord
`ing to the invention are selected. In deciding on the size
`of the ring arrangement and its location in the heart as
`well as in choosing the valve prosthesis, it has to be
`taken care that obstruction of the natural valve ori?ce is
`kept to a minimum in order to ensure maximum ef?
`ciency of the heart pumping action and to avoid causing
`any unnecessary turbulence in the blood ?ow.
`In many cases one kind of ring arrangement can ac
`commodate a number of different valve prostheses. In
`other cases speci?c prostheses require speci?c ring
`arrangements. Valve prostheses for use with the ring
`arrangements illustrated in FIGS. 1 to 16 have to be
`provided with skirts which can be pulled over the ring
`and hooks. Such skirts are preferably made of slightly
`stretchable material and are provided with a thread. To
`keep tissue growth to a minimum the skirt material may
`be coated with silicon, Silastic (Trademark), Te?on
`35
`(Trademark), or the like. In the case of mitral and tricus
`pid valve prostheses for use with the ring arrangements
`shown in FIGS. 10 to 15, it is preferred that the portion
`of the prosthesis which, in use, is in close proximity to
`the ring is covered with fabric, pads or the like to mini
`mize friction between this portion of the valve prosthe
`sis and the ring. This is particularly important in the
`case of bioprostheses, since the pericardium tissue gen
`erally used in such prostheses may be damaged by con
`stant friction due to slight movement of the prosthesis
`relative to the ring.
`While the chosen prosthesis is prepared for implant
`ing, the ring is inserted.
`In the case of an aortic valve the ring is inserted into
`the aorta in proximity to the aortic annulus above the
`ori?ce connecting the aorta with the left ventricle and
`below the ostia of the coronary arteries. If the ring is
`provided with clamps on its lower outer periphery 'or its
`lower surface, the clamps are tightened to anchor the
`ring in the tissue.
`If, as in the embodiments of FIGS. 1 to 9 the ring is
`provided with thin fabric or preferably with a fabric
`pad on its lower surface, this fabric comes to sit on the
`aortic annulus. The suturing thread is passed through
`the tissue next to the patient’s aortic annulus and then
`returned through the fabric. If interrupted sutures are
`preferred the suture is tied, otherwise the stitching is
`continued. If needed, a double needle stitch can be used.
`In this case two needles and threads are passed under
`the ring through the fabric pad from the outside of the
`ring ori?ce and returned through the aortic tissue below
`the ring to the outside. An upwardly directed ?ange
`facilitates passing of the needle underneath the ring.
`
`8
`The two thread ends are then tied. A fabric pad on the
`ring generally allows a tight connection between ring
`and tissue. If desired, pledgets may be used to reduce
`the possibility of cutting or tearing the tissue when
`tightening the suture. In this situation, the two needles
`and threads are ?rst passed through the tissued next to
`the aortic annulus and then through the fabric pad of
`the ring arrangement. The two thread ends are tied
`right away or following placement of stitches around
`the annulus. A similar procedure may be applied, if the
`ring arrangement is provided with eyelets or openings
`to receive sutures.
`After the sutures are completed the connection be
`tween ring and tissue is carefully checked in an effort to
`prevent development of perivalvular leaks or dehis
`cence once the prosthesis is in place.
`The desired aortic valve prosthesis can now be in
`serted. To this effect the skirt or sewing ring of the
`valve prosthesis is turned upwardly from the annular
`valve seat and the valve seat is placed on the ring. For
`the aortic valve it is preferred that the prosthesis is
`placed on the ring in such a way that the ori?ce of the
`valve prosthesis coincides with the ring ori?ce.
`In the illustrated embodiments the skirt of the pros
`thesis is then rolled down over the hooks and, if the
`skirt is not already provided with a thread, a suturing
`thread is passed around the ring and tied so that the skirt
`is tightly pressed against the ring. The hooks substan
`tially prevent the skirt from pulling out of the thread
`and the thread from slipping off the ring. The ?ange
`prevents the thread from moving downwardly. In this
`way the prosthesis is securely fastened to the ring and
`can withstand the varying pressures in the aorta. Op
`tionally, the hooks may be coated with a nonwtoxlc
`substance, such as a ?uorescent substance, which en
`hances visibility of the hooks.
`In cases where snap-in, screw, hook and retainer and
`similar connections are used, these connections are ef
`fected before the skirt is rolled down, if the use of an
`extended skirt is desired.
`In the case of a mitral or tricuspid valve the ring 15
`inserted into the left atrium close to the ori?c connect
`ing the left atrium with the left ventricle and the ring is
`connected to the mitral annulus in practically the same
`way as in the case of the aortic valve. After checking
`the connection between ring and tissue the desired m1
`tral valve prosthesis is inserted into the ring ori?ce so
`that it extends into the natural valve opening. Depend
`ing on the prosthesis the valve seat may be positioned
`on the ring or in the ring orifice. In the illustrated em
`bodiments of FIGS. 10 to 15 the skirt of the prosthesis
`is pulled over the ring and hooks and is tied as described
`above. It has to be taken care that the skirt is anchored
`to the hook and tied securely, since in the mitral and
`tricuspid valves the forces exerted on the closed valve
`prosthesis in systole bear on the skirt and not mainly on
`the ring as in the case of the aortic valve. For the same
`reason a mitral or tricuspid valve prosthesis of this kind
`should be provided with a strong skirt material.
`If screw connections or the like are used, these are
`effected with or without use of the skirt as indicated
`above.
`In order to reduce any thrombogenic effect the ring
`material may have, it is preferred that the surfaces of the
`ring which come into contact with blood and which are
`not already covered with fabric, are covered by the
`skirt of the prosthesis.
`
`45
`
`50
`
`55
`
`60
`
`65
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`NORRED EXHIBIT 2103 - Page 8
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`

`

`When a valve prosthesis which is connected to a ring
`arrangement according to the invention fails due to
`wear or any other reason, the valve prosthesis is re
`moved from the ring.
`In valve prostheses which are connected to the ring
`as illustrated in FIGS. 6 to 9 or 13 to 15 the skirt of the
`prosthesis is ?rst severed around the valve seat so that
`the valve prosthesis can be removed. Following this the
`thread holding the skirt to the ring is cut and removed
`together with the rest of the skirt.
`As this thread is generally in proximity to the sutures
`which hold the ring in place, there is the danger of
`accidentally cutting one of these sutures. Flanges of the
`kind illustrated facilitate cutting of the thread without
`inadvertently damaging the connection between ring
`and tissue.
`If screw or other connections are used, these are
`disconnected after the skirt, if any, has been severed,
`thus allowing the valve to be removed.
`A new valve prosthesis can then be inserted and con
`nected to the ring arrangement in any of the aforemen
`tioned ways.
`I claim:
`1. An implantable device for receiving and remov
`ably holding in place a cardiac valve prosthesis com
`prising a substantially ring-shaped structure provided
`with means allowing the strucutre to be securely at
`tached to heart tissue and with a plurality of hooks
`connected to the generally radially outwardly facing
`portion of the structure and adapted for receiving and
`retaining a sewing skirt of a valve prosthesis for remov
`ably connecting a valve prosthesis to said structure, and
`a ?ange connected to the radially outwardly facing
`portion of the structure and extending substantially
`radially outwardly.
`2. An implantable device for receiving and remov
`ably holding in place a cardiac valve prosthesis com
`prising a substantially ring-shaped structure, fabric cov
`ering a portion of said structure, said fabric allowing the
`structure to be securely sutured to heart tissue, a plural
`ity of hooks connected through the generally radially
`outwardly facing portion of the struct