United States Patent [19J
`Andersen et al.
`
`I 1111111111111111 11111 111111111111111 11111 11111 1111111111111111 Ill lllll llll
`US005840081A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,840,081
`Nov. 24, 1998
`
`[54] SYSTEM AND METHOD FOR IMPLANTING
`CARDIAC VALVES
`
`[76]
`
`Inventors: Henning Rud Andersen, Dalvangen
`37A, DK-8270 Hoejbjerg; John
`Michael Hasenkam, Aprilvej 8,
`DK-8210 Aarhus V; Lars Lyhne
`Knudsen, RudolfWulffsgade 6,4,
`DK-8000 Aarhus C, all of Denmark
`
`[21] Appl. No.: 801,036
`
`[22] Filed:
`
`Feb. 19, 1997
`
`Related U.S. Application Data
`
`[63] Continuation of Ser. No. 569,314, Dec. 8, 1995, abandoned,
`which is a continuation of Ser. No. 352,127, Dec. 1, 1994,
`abandoned, which is a division of Ser. No. 261,235, Jun. 14,
`1994, Pat. No. 5,411,552, which is a continuation of Ser. No.
`961,891, filed as PCT/DK91/00134 May 16, 1991 published
`as WO91/17720 Nov. 28, 1991, abandoned.
`
`[30]
`
`Foreign Application Priority Data
`
`FOREIGN PATENT DOCUMENTS
`
`0103546
`0103546 Al
`1258406
`1271508
`2056023
`9117720
`9217118
`
`3/1984
`3/1984
`9/1986
`11/1986
`3/1981
`11/1991
`10/1992
`
`European Pat. Off. ................... 623/2
`European Pat. Off ..
`U.S.S.R ..................................... 623/2
`U.S.S.R ..................................... 623/2
`United Kingdom .
`WIPO.
`WIPO.
`
`OTHER PUBLICATIONS
`
`Sixteenth Edition of The Merck Manual of Diagnosis and
`Therapy (1992) "Valvular Heart Disease," p. 546-553.
`Yamaguchi, Case Description, "A Case of a Reoperation
`using a Balloon Catheter with blocked Pars Ascendes Aor(cid:173)
`tae," Kyobu Geka, Oct. 1989, 42:11, pp. 961-964.
`World Medical Manufacturing Corporation, Talent Endo(cid:173)
`vascular Bifurcated Spring Graft System Composite Design
`brochure, no date.
`
`Primary Examiner-David H. Willse
`Attorney, Agent, or Firm-Jeffry J. Grainger; Jens E.
`Hoekendijk; Michael J. Lynch
`
`May 18, 1990
`
`[DK]
`
`Denmark ................................. 1246/90
`
`[57]
`
`ABSTRACT
`
`Int. Cl.6
`........................................................ A61F 2/24
`[51]
`[52] U.S. Cl. ................................................. 623/2; 606/108
`[58] Field of Search ........................ 623/2, 900; 606/108;
`600/36
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`7/1990 Onik.
`Re. 33,258
`3,409,013 11/1968 Berry .
`3,587,115
`6/1971 Shiley .
`3,671,979
`6/1972 Moulopoulos .............................. 623/2
`9/1973 Hancock.
`3,755,823
`............................. 623/2
`4,056,854 11/1977 Boretos et al.
`4,106,129
`8/1978 Carpentier et al. .
`4,222,126
`9/1980 Boretos et al. .
`4,574,803
`3/1986 Starz .
`4,580,568
`4/1986 Gianturco .
`4,592,340
`6/1986 Boyles ........................................ 623/2
`4,612,011
`9/1986 Kautzky .
`
`A valve prosthesis (9) for implantation in the body by use of
`catheter (11) comprises a stent made from an expandable
`cylinder-shaped thread structure (2,3) comprising several
`spaced apices ( 4). The elastically collapsible valve ( 4) is
`mounted on the stent as the commissural points (5) of the
`valve (6) are secured to the projecting apices ( 4).
`
`The valve prosthesis (9) can be compressed around the
`balloon means (13) of the balloon catheter (11) and be
`inserted in a channel, for instance in the aorta (10). When the
`valve prosthesis is placed correctly the balloon means (13)
`is inflated thereby expanding the stent and wedging it
`against the wall of aorta. The balloon means is provided with
`beads (14) to ensure a steady fastening of the valve pros(cid:173)
`thesis on the balloon means during insertion and expansion.
`
`The valve prosthesis (9) and the balloon catheter (11) make
`it possible to insert a cardiac valve prosthesis without a
`surgical operation comprising opening the thoracic cavity.
`
`(List continued on next page.)
`
`8 Claims, 4 Drawing Sheets
`
`C:12 ►
`
`13
`
`........ 19
`
`17
`
`18
`
`16
`... C'.
`
`Medtronic Exhibit 1013
`Medtronic Corevalve v. Colibri Heart Valve
`IPR2020-01454
`Page 00001
`
`

`

`5,840,081
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`4,631,052 12/1986 Kensey .
`4,733,665
`3/1988 Palmaz .................................... 606/108
`4,777,951 10/1988 Cribier et al. .
`4,787,899 11/1988 Lazarus .
`4,787,901 11/1988 Baykut.
`4,796,629
`1/1989 Grayzel .
`4,878,495 11/1989 Grayzel .
`4,883,458 11/1989 Shiber .
`4,966,604 10/1990 Reiss .
`4,979,939 12/1990 Shiber .
`4,986,830
`1/1991 Owens et al. .
`4,994,077
`2/1991 Dobben ....................................... 623/2
`5,007,896
`4/1991 Shiber .
`5,011,488
`4/1991 Ginsburg .
`5,026,366
`6/1991 Leckrone .
`
`5,032,128
`5,047,041
`5,080,660
`5,089,015
`5,152,771
`5,163,953
`5,167,628
`5,295,958
`5,332,402
`5,397,351
`5,411,552
`5,443,446
`5,480,424
`5,545,209
`5,593,405
`
`7/1991 Alonso.
`9/1991 Samuels.
`1/1992 Buelna.
`2/1992 Ross.
`10/1992 Sabbaghian et al. .
`11/1992 Vince.
`12/1992 Boyles.
`3/1994 Shturman.
`7/1994 Teitelbaum .
`3/1995 Pavcnik et al. .
`5/1995 Andersen et al. .
`8/1995 Shturman.
`1/1996 Cox.
`8/1996 Roberts et al. .
`1/1997 Osypka.
`
`IPR2020-01454 Page 00002
`
`

`

`U.S. Patent
`
`Nov. 24, 1998
`
`Sheet 1 of 4
`
`5,840,081
`
`25
`
`------2
`
`FIG. I
`
`4
`
`5
`
`4
`
`8
`
`7
`
`4
`
`5
`
`FIG. 2
`
`IPR2020-01454 Page 00003
`
`

`

`U.S. Patent
`US. Patent
`
`Nov. 24, 1998
`
`Sheet 2 of 4
`
`5,840,081
`5,840,081
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`IPR2020-01454 Page 00004
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`U.S. Patent
`US. Patent
`
`Nov. 24, 1998
`Nov. 24, 1998
`
`Sheet 3 of 4
`Sheet 3 0f 4
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`5,840,081
`5,840,081
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`IPR2020-01454 Page 00005
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`

`

`U.S. Patent
`
`Nov. 24, 1998
`
`Sheet 4 of 4
`
`5,840,081
`
`6
`
`FIG. 11
`
`FIG. 12
`
`IPR2020-01454 Page 00006
`
`

`

`5,840,081
`
`1
`SYSTEM AND METHOD FOR IMPLANTING
`CARDIAC VALVES
`
`This is a continuation of application Ser. No. 08/569,314,
`filed Dec. 8, 1995, now abandoned, which is a continuation
`of application Ser. No. 08/352,127, filed Dec. 1, 1994, now
`abandoned, which is a divisional of application Ser. No.
`08/261,235, filed Jun. 14, 1994, now U.S. Pat. No. 5,411,
`552, which was continuation of application Ser. No. 07/961,
`891, filed as PCT/DK91/00134 May 16, 1991 published as 10
`WO91/17720 Nov. 28, 1991, now abandoned.
`
`BACKGROUND OF THE INVENTION
`
`2
`Even though this patent contains no detailed explanation, the
`description indicates that this valve prosthesis is designed
`for implantation and sewing on by a surgical intervention.
`Moreover, from U.S. Pat. Nos. 4,856,516 and 4,733,665
`5 different shapes of expandable stents are known. These
`stents are made to be expanded by impression of a radially
`outward force coming from a balloon catheter or the like.
`These stents are made to reinforce the wall when there is a
`risk that the channel is closed and/or compressed.
`The nearest prior art may be that the described in GB-A-
`2,056,023. This document discloses an elastic stent as
`described by way of introduction. Thus, the stent described
`comprises an elastic collapsible valve mounted on the cyl(cid:173)
`inder surface of a cylindrical stent. However, the valve
`15 prosthesis including the stent is designated for mounting
`through a surgical intervention. Even though the stent is
`slightly collapsible, it will not be suited for implantation by
`a catheterization procedure.
`
`The present invention relates to a valve prosthesis, pref(cid:173)
`erably a cardiac valve prosthesis, for implantation in the
`body and comprising a collapsible elastic valve which is
`mounted on an elastic stent wherein the commissural points
`of the elastic collapsible valve are mounted on the cylinder
`surface of the elastic stent.
`Valve prostheses of this type are usually implanted in one
`of the channels of the body to replace a natural valve. In the
`present description the invention will be explained in con(cid:173)
`nection with a cardiac valve prosthesis for implantation in
`aorta. However, it will be possible to use a valve prosthesis 25
`according to the invention in connection with implantation
`in other channels in the body by using the same technique as
`the one used for implantation of cardiac valve prosthesis.
`Such an implantation may, e.g., comprise the implantation
`of:
`1. a valve (for instance a cardiac valve) in the veins,
`2. a valve in the esophagus and at the stomach,
`3. a valve in the ureter and/or the vesica,
`4. a valve in the biliary passages,
`5. a valve in the lymphatic system, and
`6. a valve in the intestines.
`An existing natural valve in the body is traditionally
`replaced with a valve prosthesis by a surgical implantation.
`However, a surgical implantation is often an exacting opera(cid:173)
`tion. Thus, today the implantation of cardiac valves are
`solely made by surgical technique where the thoracic cavity
`is opened. The operation calls for the use of a heart and lung
`machine for external circulation of the blood as the heart is
`stopped and opened during the surgical intervention and the
`artificial cardiac valves are subsequently sewed in.
`Due to its exacting character, it is impossible to offer such
`operation to certain people. For instance, this is due to the
`fact that the person is physically weak because of age or
`illness. Moreover, the number of heart and lung machines
`available at a hospital will be a substantially limiting factor.
`Cardiac valve prostheses that need no surgical interven(cid:173)
`tion are known as there are used for implantation by means
`of a technique of catheterization. Examples of such valve
`prostheses are described in U.S. Pat. Nos. 3,671,979 and
`4,056,854. However, both of these valve prostheses are
`connected to means which lead to the surface of the patient
`either for a subsequent activation of the valve or for a
`subsequent reposition or removal of the valve prosthesis.
`With these valve prostheses it is impossible to make an
`implantation which makes it possible for the patient to
`resume a substantially normal life in the same way as it is
`possible in connection with a surgical implantation of a
`cardiac valve.
`From U.S. Pat. No. 3,755,823 an elastic stent for a cardiac
`valve prosthesis is known. However, this valve prostheses is
`not designed for implantation in the body by catheterization.
`
`20
`
`SUMMARY OF THE INVENTION
`
`35
`
`It is the object of the present invention to provide a valve
`prosthesis of the type mentioned in the introductory part,
`which permits implantation without surgical intervention in
`the body and by using a catheter technique known per se and
`which makes it possible for the patient to resume a substan(cid:173)
`tially normal life.
`This is achieved according to the invention with a valve
`prosthesis of the type mentioned in the introductory part,
`which is characterized in that the stent is made from a
`30 radially collapsible and re-expandable cylindrical support
`means for folding and expanding together with the collaps(cid:173)
`ible valve for implantation in the body by means of a
`technique of catheterization.
`The collapsible elastic valve is mounted on the stent for
`instance by gluing, welding or by means of a number of
`suitable sutures.
`If the support means are made from a thread structure, this
`can for instance be grate shaped, loop shaped or helical. This
`40 makes it possible to compress the stent and the collapsible
`valve mounted thereon for placing on the insertion catheter.
`The use of a non-self-expandable stent may, e.g., be effected
`by a compression of the stent around the expansion arrange(cid:173)
`ment of the catheter which preferably consists of a balloon.
`45 When using a self-expandable stent, a catheter with an
`expansion arrangement is not used. In this case the stent is
`compressed and is inserted into an insertion or protection
`cap from which the stent is eliminated after implantation in
`order to obtain an expansion due to the stresses in the
`50 compressed support means, which for instance may be made
`from plastics or metal. After the compression the entire outer
`dimension is relatively small, which makes it possible to
`introduce the valve prostheses through a channel in the body.
`When the valve prosthesis is introduced and placed
`55 correctly, the stent is expanded by self-expansion or by
`means of the expansion arrangement until the stent is given
`an outer dimension which is slightly larger than the channel
`in which it is placed. As the stent is elastic, a contraction of
`the stent is prevented once it is expanded. The stiffness in the
`60 material of the support means contributes to maintain the
`expanded shape of the stent. After the expansion is made, the
`expansion arrangement of the catheter is contracted and the
`catheter can be removed from the channel. The inlet opening
`can subsequently be closed and the patient will then be able
`65 to resume a normal life.
`The valve prosthesis according to the invention does not
`require an actual operation but merely a small intervention
`
`IPR2020-01454 Page 00007
`
`

`

`5,840,081
`
`3
`to optionally expose the body channel, e.g., a vein, through
`which the insertion takes place. Thus, patients for whom an
`operation would be associated with high risk can be offered
`implantation of, for instance, cardiac valves. After the
`implantation has taken place, the after-treatment will advan-
`tageously be shorter than normal, which means fewer hos(cid:173)
`pital days for the patient. Moreover, it is assumed that it will
`be possible to implant the valve prosthesis under local
`anaesthetic.
`The valve prosthesis can be used to replace a natural valve 10
`or to establish a new valve function in one of the channels
`in the body which do not naturally contain a valve. For
`instance this goes for veins (arteries and veins) on a place
`without natural valves. The function of the valve prosthesis
`is then to ensure that the blood flows in one direction only.
`The valve is meant to be used in veins in the legs of persons
`suffering from varicose veins (varices).
`In persons having varicose veins the blood flows in a
`wrong direction, viz. from the central veins in the center of
`the leg towards the superficial veins. Among other things,
`this is due to the changed pressure in the legs, upright
`working position and other conditions. A valve prosthesis
`according to the invention may easily be placed in the veins
`and prevent the flow of the blood in a wrong direction.
`Also, the valve prosthesis can be used in connection with
`diseases, for instance cancerous tumors, where too much
`humour is produced. If the humour is able to flow from the
`cancerous tumor through several channels, it is possible to
`drain the humour in one desired direction through the
`channels of the body by an appropriate placing of the valve
`prosthesis.
`When the valve prosthesis is used as a cardiac valve
`prosthesis in the aorta, it is possible to mount it in three
`positions, viz., in the descending part of the aorta in a
`position between the coronary arteries and the left ventricle
`of the heart, or in the aorta in a position immediately after
`the mouth of the coronary arteries.
`The cardiac valve prosthesis can also be used in other
`places than in the aorta. Thus, the valve prosthesis can be 40
`used in the pulmonary artery and/or the right ventricle of the
`heart for replacing the pulmonary valves. Likewise, the
`cardiac valve prosthesis can be used in the passage between
`the right auricle of the heart and the right ventricle of the
`heart (tricuspidalostium) and the passage between the left 45
`auricle of the heart and the left ventricle of the heart
`(mistralostium) for replacing the tricuspidal valve and the
`mitral valve, respectively.
`Even though the cardiac valve preferably is meant to be
`used for patients suffering from aorta insufficiency and who
`cannot be offered an open heart surgery, the valve prosthesis
`can also be used for patents in connection with treatment of
`aorta stenosis. Several of the patients with aorta stenosis are
`elderly people who cannot be offered a surgical cardiac
`operation. The patients are offered balloon dilatation of the 55
`aorta stenosis which may result in an aorta insufficiency as
`a side effect of the treatment.
`As to these patients it is possible to insert a valve
`prosthesis in the descending or ascending part of the aorta
`thoracalis a few days or weeks before the balloon dilatation. 60
`As a result thereof, the left ventricle is protected against
`weight if the subsequent balloon dilatation of the stenosis
`results in aorta insufficiency. In certain cases the weight
`(reflux) on the left ventricle is reduced by up to approxi(cid:173)
`mately 75%.
`Furthermore, the stent may be made with a relatively great
`height and with a cylinder surface which is closed by a
`
`65
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`FIG. 1 shows a stent 1 made by support means in the form
`of two 0.55 mm surgical stainless steel wires 2,3. The wires
`
`5
`
`4
`suitable material. Thus, a vascular prosthesis known per se
`is formed wherein the valve is mounted. This may facilitate
`the implantation of the valve prosthesis, for instance in the
`arcus aorta. Moreover, the great surface which abuts the
`inner wall of the channel contributes to ensure the securing
`of the valve prosthesis in the channel. This embodiment is
`also suitable as valve prosthesis which is inserted in veins.
`As veins have relatively thin and weaker walls than arteries,
`it is desirable that the valve prosthesis has a greater surface
`to distribute the outward pressure which is necessary to
`secure the valve prosthesis.
`Moreover, the invention relates to a balloon catheter for
`implanting a valve prosthesis according to the invention and
`comprising a channel for injection of a fluid for the inflation
`of the balloon means of the catheter and an insertion cap
`15 wherein the balloon means of the catheter and a collapsible
`valve prosthesis mounted thereon are located during the
`injection, characterized in that the balloon means are pro(cid:173)
`vided with profiled surface which is made to ensure a steady
`fastening of the valve prosthesis during the withdrawal of
`20 the balloon means from the protection cap and the subse(cid:173)
`quent inflation for the expansion of the stent.
`Different balloon catheters for implanting cores in the
`body are known. For instance, such balloon catheters are
`known from U.S. Pat. Nos. 4,856,516, 4,733,665 and 4,796,
`25 629 and from DE publication No. 2,246,526. However, the
`known balloon catheters have a smooth,or a slightly wavy
`surface. The use of such balloon catheter is disadvantageous
`for mounting a valve prosthesis in a channel having a large
`flow as for instance the aorta. A large humour flow is able to
`30 displace the stent on the smooth surface of the balloon and
`makes an accurate positioning difficult. This drawback has
`been remedied with the balloon catheter according to the
`present invention as the profiled surface prevents a displace(cid:173)
`ment of the valve prosthesis in relation to the balloon means
`during introduction and the subsequent inflation of the
`35 balloon means.
`In connection with the implantation, any prior art tech(cid:173)
`nique may be used to supervise an accurate introduction and
`positioning of the valve prosthesis. Thus, guide wires for the
`catheter, X-ray supervision, injection of X-ray traceable
`liquids, ultrasonic measuring, etc. may be used.
`DESCRIPTION OF THE DRAWINGS
`The invention will now be explained in detail with
`reference to the accompanying schematical drawing,
`wherein
`FIG. 1 shows a perspective view of a stent without a
`valve,
`FIG. 2 is a perspective view of a valve prosthesis accord(cid:173)
`ing to the invention made from the stent shown in FIG. 1
`50 having a biological valve mounted thereon,
`FIG. 3 is a partial view through the aorta illustrating a
`partially inflated balloon catheter,
`FIG. 4 is a cross section through the embodiment shown
`in FIG. 9,
`FIGS. 5-7 are views illustrating the introduction and
`implantation of a valve prosthesis of the invention in the
`aorta,
`FIGS. 8-10 are views illustrating three possible positions
`of a cardiac valve prosthesis, and
`FIGS. 11-12 are perspective views illustrating two further
`embodiments of a valve prosthesis having a closed cylin(cid:173)
`drical wall.
`
`IPR2020-01454 Page 00008
`
`

`

`5,840,081
`
`10
`
`5
`are folded in 15 loops. Three loops 4 are 14 mm in height
`and are intended to secure the commissural points 5 (see
`FIG. 2) from a biological cardiac valve 6 which is mounted
`in the stent 1. The remaining loops have a height of 8 mm.
`These loops form circumferentially expandable sections 25 5
`between the commissural points 5 forming commissural
`supports. Each of the two folded wires 2,3 is bent to form
`rings 7,8 which are closed by welding the ends. The two
`rings are placed on top of each other as will appear from
`FIG. 1 and they are mutually secured by means of a number
`of sutures (not shown). The lower ring is circumferentially
`expandable at least along sections thereof which correspond
`to the circumferentially expandable sections 25. By using a
`substantially cylindrical thread structure projecting apices, a
`reduction in weight is obtained as compared to a stent which 15
`is exclusively cylindrical with the same loop heights for all
`the loops.
`The biological valve 6 was removed from a slaughtered
`pig of 100 kg. The valve was cleaned before mounting in the
`stent 1. The cleaned valve has an outer diameter of 25-27 20
`mm and the height of the three commissural points 5 is 8
`mm. The valve 6 is mounted in the stent by means of a
`suitable number of sutures to form the cardiac valve pros(cid:173)
`thesis 9 shown in FIG. 2. The valve prosthesis produced is
`used for performing tests in pigs by implantation of cardiac
`valve prosthesis. However, the cardiac valve prosthesis for
`use in human beings has a corresponding form.
`FIG. 3 shows a partial view through the aorta 10. A
`balloon catheter 11 is introduced in the aorta according to the
`direction of an arrow 12. In the Figure shown the balloon
`means 13 of the balloon catheter is led out of the protection
`cap llA and is partly inflated through a fluid channel 15,
`which is led to the surface of the patient. The balloon means
`13 constitutes a tri-sectional balloon upon which the cardiac
`valve prosthesis is placed. In the form shown, the cardiac
`valve prosthesis is expanded exactly to be in contact with the
`aorta 10. The balloon means 13 is provided with three
`projecting beads 14 which are engaged with the one side of
`the cardiac valve prosthesis 9. The blood flowing through
`the aorta according to the direction of an arrow 16 will thus
`cause the cardiac valve prosthesis 9 to abut on the beads 14
`and the valve cannot be displaced in relation to the balloon
`means 13. Moreover, the balloon catheter used comprises a
`central channel 17 to receive a guide wire 18 which is used
`in a way known per se for supervising the introduction of the
`catheter through fluoroscopi. In the shown embodiment
`beads 14 are only used at one side of the valve prosthesis,
`but, however, it will often be desirable to use the beads in
`pairs placed along lines parallel to the longitudinal axes 19
`through the balloon means 13. In this case the spacing of the
`pair of beads 14 will correspond to the height of the loops
`of the stent. This makes it possible to make an effective
`fastening of a valve prosthesis on balloon means. Moreover,
`the fastening on the balloon means may be provided by
`using balloon means with an indentation in the surface (not
`shown).
`FIG. 4 shows a cross section through the embodiment
`shown in FIG. 3 illustrating the placing of the beads 14 on
`the tri-sectional balloon means 13.
`A balloon catheter of the above-described type which was
`used in tests of implanting of cardiac valve prosthesis 9 in
`pigs had the following dimensions. Each of the three bal(cid:173)
`loons was 60 mm in length and 15 mm in diameter. The total
`diameter for the three inflated balloons was 31 mm and in
`the balloon catheter used two beads 14 having a height of 3
`mm were mounted on each side of the three balloons. The
`beads had a spacing of 15 mm. The protection cap llA of the
`
`6
`balloon catheter had an outer diameter of 13.6 mm and an
`inner diameter of 12.5 mm and a length of 75 cm. The
`balloon catheter was provided with a standard guide wire
`having a diameter of 0.9 mm and a length 300 cm.
`FIGS. 5-7 show the valve prosthesis 9 at different steps
`in introducing and implanting in the aorta 10 by means of the
`catheter 11 having the inflatable balloon means 13. The
`cardiac valve prosthesis 9 is initially placed above the
`deflated balloon means 13 and compressed manually around
`the balloon means (FIG. 5), whereafter the outer diameter
`for the valve prosthesis is approximately 10 mm. After the
`introduction and positioning, the balloon means 13 is
`inflated (FIG. 6), thereby contributing an outer dimension of
`approximately 30 mm to the cardiac valve prosthesis. To
`obtain an effective fastening in the aorta, the outer dimen(cid:173)
`sion of the cardiac valve prosthesis is greater than the
`diameter of the aorta. This means that the prosthesis is tight
`against the inner wall of the aorta with a pressure which is
`sufficiently large to counteract a detachment due to the flow
`of the blood. The balloon catheter 11 may subsequently be
`removed from the aorta 10 (FIG. 7). Due to the stiffness of
`the metal the valve prosthesis will prevent a contraction.
`However, smaller contractions may occur ( <10% diameter
`reduction) after the deflation and removal of the balloon
`25 catheter 13. When the valve prosthesis is mounted as shown
`in FIG. 7, the patient will be able to resume a substantially
`normal life after a few days.
`FIGS. 8-10 show the positioning of the valve prosthesis
`9 as cardiac valve prosthesis in the aorta 10 in three different
`30 positions, i.e., in a position between the coronary arteries 20
`and the left ventricle of the heart 21 (FIG. 8), in a position
`immediately after the mouth of the coronary arteries in the
`ascending part of the aorta (FIG. 9), and in a position in the
`descending part of the aorta 10. The positioning of the valve
`35 prosthesis is chosen in accordance with the diagnosis of the
`illness of the patient. By placing the cardiac valve prosthesis
`as shown in FIG. 8, there is a risk of detachment and/or
`covering the mouth of the coronary arteries, and therefore it
`is preferred to use a higher stent which, for instance,
`40 comprises several ranges placed on top of each other. This
`allows a fixation of the prosthesis at a place after the mouth
`of coronary arteries even though the valve itself is in the
`position between the coronary arteries and the left ventricle.
`FIGS. 8 and 9 show how a contrast medium 23 is injected
`45 by means of a so-called pigtail catheter for registration of
`tightness of the implanted valve prosthesis 9.
`A specific embodiment for a valve prosthesis and a
`balloon catheter for implanting the valve prosthesis has been
`explained above. However, it is obvious that it is possible to
`50 modify the valve prosthesis depending on the desired use,
`and moreover, it is possible to modify the catheter used in
`the implantation. Thus, the stent of the valve prosthesis may
`be made solely of one closed ring folded in a number of
`loops or with three or more mutually secured loop-shaped
`55 rings placed on top of each other. Moreover, it is possible to
`make the stent having a thread structure which instead of
`loops is grate shaped, helical or is formed otherwise if only
`it is ensured that the form of the stent permits the compres(cid:173)
`sion and expansion of the stent and fastening of the collaps-
`60 ible valve. Instead of a biological valve it might be possible
`to use other collapsible valves, such as valves made from
`synthetic materials, e.g., polyurethane. It is also possible to
`use valves with more or fewer flaps than three.
`It is possible to make the valve prosthesis with a closed
`65 cylinder surface as illustrated in FIGS. 11 and 12. In both
`Figures the support means of the valve prosthesis is made of
`an elongated tubular means 24 having a closed cylinder
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`30
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`surface. This valve prosthesis is intended to expand by
`self-expansion or by means of a catheter according to the
`invention. This prosthesis is especially suitable for placing
`in veins and other channels where only a small pressure is
`exerted against the wall of the channel. In FIG. 11 the valve 5
`6 is mounted at the end of the tubular means 24. In FIG. 12
`an embodiment is shown where the valve 6 is mounted in a
`central position in the tubular means 24.
`An explanation of a method of implanting a valve pros(cid:173)
`thesis according to the invention is given below:
`a valve prosthesis 9 made of a stent 1 and a collapsible
`valve 6, as described above, is placed on a deflated
`balloon means and is manually compressed thereon,
`the balloon means 13 and the valve prosthesis are drawn
`into an insertion cover llA,
`a guide wire 18 is inserted into the left ventricle of the
`heart through the central opening 17 of the balloon
`catheter under continuous fluoroscopi,
`the insertion cover llA conveys the guide wire 18 to a
`point in the channel in the immediate vicinity of the
`desired position of the valve prosthesis,
`the balloon means 13 is pushed out of the protection cap
`llA and the valve prosthesis is positioned in the desired
`position if necessary by use of further registration 25
`means to ensure an accurate positioning,
`the balloon means 13 is inflated with a certain overstretch(cid:173)
`ing of the channel,
`the balloon means 13 is deflated, and
`the balloon means 13, the guide wire 18 and the protection
`cap llA are drawn out and the opening in the channel,
`if any, wherein the valve prosthesis is inserted can be
`closed.
`We claim:
`1. A system for implanting a valve in a body channel
`having an inner wall, the system comprising:
`a radially collapsible and expandable cylindrical stent;
`a radially collapsible and expandable valve mounted to
`the stent; and
`a catheter for introducing and securing the valve in the
`body channel, the catheter comprising an expandable
`member about which the cylindrical stent may be
`positioned together with the valve, fastening means on
`the expandable member on which the stent may be
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`10
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`8
`mounted to the expandable member, and a channel
`extending through the catheter for injecting a fluid into
`the expandable member so as to expand the expandable
`member from a collapsed profile suitable for introduc(cid:173)
`tion into the body channel to an expanded profile in
`which the stent engages the inner wall of the body
`channel so as to secure the valve therein.
`2. A system as in claim 1 wherein the expandable member
`comprises a balloon.
`3. A system as in claim 2 wherein the fastening means
`comprises a plurality of beads on the surface of the balloon.
`4. A system as in claim 1 wherein the valve comprises a
`trilobate valve having a plurality of commissural points.
`5. A system as in claim 4 wherein the stent comprises a
`15 plurality of circumferentially spaced apices for supporting
`the commissural points of the valve.
`6. A system as in claim 5 wherein the stent comprises at
`least one wire bent so as to form a plurality of circumfer(cid:173)
`entially spaced loops, a first portion of the loops comprising
`20 the apices for supporting the commissural points of the
`valve, and a second portion of the loops lying between the
`apices to allow the stent to radially expand and collapse.
`7. A method of implanting a valve in a body channel
`having a wall, the method comprising:
`introducing a catheter into the body channel, the catheter
`including an expandable member near a distal end
`thereof, a fluid channel in communication with the
`expandable member, and a cylindrical stent mounted to
`the expandable member, the valve being mounted to the
`cylindrical stent, wherein the expandable member, the
`stent and the valve are in a collapsed configuration
`during said introducing;
`advancing the catheter within the body channel to a
`position wherein the valve is to be implanted; and
`radially expanding the expandable member together with
`the cylindrical stent and the valve by injecting a fluid
`through the fluid channel such that the stent engages the
`wall of the body channel so as to be secured therein.
`8. The method of claim 7 wherein the step of radia