tilled States atet [191
`llanenelr
`
`[54] FLEXIBLE STENT FOR HEART VALVE
`[75] Inventor: Warren 11). ll-lancoelt, Santa Ana,
`Calif.
`.
`
`[73] Assignee: Hancock Laboratories Incorpora
`tion, Orange, Calif.
`Apr. 23, I971
`[22] Filed:
`[21] Appl. No.: 136,832
`
`[52] US. Cl. ...................................... .. 3/1, 3/D1G. 3
`{51] lint. Cl. ............................................ ..A61i 1/22
`[58] Field of Search .............................. .. 3/1, D10. 3
`
`[56]
`
`References Cited
`UNITED STATES PATENTS
`
`3,570,014
`3,197,788
`
`3/1971
`Hancock ................................... .. 3/1
`8/1965
`Segger ...................................... .. 3/1
`OTHER PUBLICATIONS
`“Heart Valve Replacement With Reinforced Aortic
`Heterografts“ by M. l. Fonescu et al. The Journal of
`Thoracic & Cardiovascular Surgery, Vol. 56, No. 3,
`Sept. 1968, pp. 333-348.
`“Clinical Experience With Supported Homograft Heart
`Valve For Mitral and Aortic Valve Replacement” by S.
`Sugie et al., The Journal of Thoracic & Cardiovascular
`
`23
`3,7
`[11]
`r
`[451 septa, 197a
`
`Surgery, Vol. 57, No. 4. Apr. 1969, pp. 455-462.
`“Pig Aortic Valve as a Replacement for Mitral Valve
`in the Dog," by W. A. Reed et al., The Journal of Tho
`racic and Cardiovascular Surgery, Vol. 57, No. 5, May
`1969, pp. 663-667.
`
`Primary Examiner-Richard A. Gaudet
`Assistant Examiner~Ronald L. Frinks
`Attorney~Gausewitz, Carr & Rothenberg
`
`ABSTRACT
`[5 7]
`An arrangement for heart valves that includes a stent
`having apexes interconnected by arms, the apexes
`being deflectable inwardly upon hemodynamic loading
`of the heart valve for reducing the stress in the valve tis
`sue, the stent being covered by a cloth sleeve which
`may have an integral bead or flap llor attachment to the
`heart, padding being provided beneath portions of the
`sleeve for protection, and a reinforcing ring extending
`around the assembly over the marginal portions of the
`heart valve, with sutures extending through the rein
`forcing ring and tissue of the heart valve for forming an
`attachment to the stem.
`27 Claims, 12 Drawing Figures
`
`(cid:47)(cid:48)(cid:51)(cid:51)(cid:38)(cid:37)(cid:1)(cid:38)(cid:57)(cid:41)(cid:42)(cid:35)(cid:42)(cid:53)(cid:1)(cid:19)(cid:18)00(cid:1)(cid:14)(cid:1)(cid:49)(cid:66)(cid:72)(cid:70)(cid:1)(cid:18)
`(cid:46)(cid:70)(cid:69)(cid:85)(cid:83)(cid:80)(cid:79)(cid:74)(cid:68)(cid:13)(cid:1)(cid:42)(cid:79)(cid:68)(cid:15)(cid:13)(cid:1)(cid:46)(cid:70)(cid:69)(cid:85)(cid:83)(cid:80)(cid:79)(cid:74)(cid:68)(cid:1)(cid:55)(cid:66)(cid:84)(cid:68)(cid:86)(cid:77)(cid:66)(cid:83)(cid:13)(cid:1)(cid:42)(cid:79)(cid:68)(cid:15)(cid:13)
`(cid:7)(cid:1)(cid:46)(cid:70)(cid:69)(cid:85)(cid:83)(cid:80)(cid:79)(cid:74)(cid:68)(cid:1)(cid:36)(cid:80)(cid:83)(cid:70)(cid:87)(cid:66)(cid:77)(cid:87)(cid:70)(cid:13)(cid:1)(cid:45)(cid:45)(cid:36)
`(cid:87)(cid:15)(cid:1)(cid:53)(cid:83)(cid:80)(cid:90)(cid:1)(cid:51)(cid:15)(cid:1)(cid:47)(cid:80)(cid:83)(cid:83)(cid:70)(cid:69)(cid:13)(cid:1)(cid:46)(cid:15)(cid:37)(cid:15)
`(cid:36)(cid:66)(cid:84)(cid:70)(cid:1)(cid:42)(cid:49)(cid:51)(cid:19)(cid:17)(cid:18)(cid:21)(cid:14)(cid:17)(cid:17)(cid:18)(cid:18)(cid:17)
`
`

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`NORRED EXHIBIT 2100 - Page 2
`NORRED EXHIBIT 2100 — Page 2
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`NORRED EXHIBIT 2100 - Page 3
`NORRED EXHIBIT 2100 — Page 3
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`NORRED EXHIBIT 2100 - Page 4
`NORRED EXHIBIT 2100 — Page 4
`
`

`
`I
`FLEXIBLE STENT FOR HEART VALVE
`
`BACKGROUND OF THE INVENTION
`l. Field of the Invention
`This invention relates to a supporting framework, or
`stent, for a natural or synthetic heart valve.
`2. Description of Prior Art
`It has been established that a stent is a useful arrange
`ment for supporting a natural or synthetic heart valve
`for implantation in the human heart. The design shown
`in US. Pat. No. 3,570,014 offers advantages in prop
`erly supporting the valve and permitting its advance
`preparation for storage until the requirement for use
`arises. There has remained, however, room for im~
`provement, particularly in assuring the reliability of the
`valve and its proper functioning over a long period of
`time. Malfunctioning of the valve may be caused by
`overstressing the valve tissue by the hemodynamic
`pressure imposed upon it when in use. Further areas of
`continued problems involve the ?xing of the valve in
`the heart so as to provide a bed for ingrowth or attach~
`ment of tissue and a hemodynamic seal while avoiding
`clotting.
`
`3,755,823
`
`2
`a frustoconical inner .wall which. assures that the ring
`does not interfere with the ?exing of the stent from the
`pressures on the heart ‘valve.
`Improved means, also may be included for more
`readily attaching the tissue to the stent and providing
`a matrix for ingrowth and subsequent ?xation of the
`donor valve by the host tissue. This may include a cloth
`sleeve around the stent entirely covering it, together
`with an annular ring of cloth or sponge on the exterior
`of the unit at the end of the apexes extending over the
`marginal edge of the heart valve. The sutures for at
`taching the heart valve to the stent pass through the
`‘cloth ring as well, which reinforces the loops of the su—
`tures so that they do not tend to cut through the tissue
`of the valve. Felt packing is included at apexes beneath
`the cloth sleeve to protect the cloth and sutures from
`abrading through contact with the stent.
`The cloth sleeve around the stent may be provided
`with a bead intermediate the upper and lower arms,
`which also facilitates attachment to the heart and the
`ingrowth of tissue. When used in the mitral position,
`there is a projecting ?at ring of cloth provided at the
`end of the stent opposite the apexes. This provides a
`means for suturing the valve assembly in the heart, re
`sulting in a hemodynamic seal and a suitable bed over
`which tissue can be af?xed or ingrown upon the graft
`ing of the heart valve assembly.
`
`5
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`20
`
`25
`
`SUMMARY OF THE INVENTION
`The present‘ invention provides an improved arrange
`ment for supporting a natural or synthetic heart valve
`in which the reliability of the valve is signi?cantly im
`proved. The invention contemplates the use of a stent
`which may bear a resemblance in‘appearance to that of
`the aforementioned US. Pat. No. 3,570,014. It in
`cludes three spaced apexes to support the valve com
`missures, with arms interconnecting the apexes. How
`ever, unlike the stent of that patent and other previous
`designs, the stent of the present invention is resilient.
`This allows de?ection of the three apexes of the stent
`when the valve is subject to hemodynamic pressure
`during diastole. As the apexes are resiliently bent in
`wardly toward the axis of the stent, the stress in the tis
`sue of the heart valve is correspondingly reduced. The
`result is a major improvement in the reliability of the
`valve, with an attendant reduction in danger to the life
`of the patient. The stent returns to its normal full diam
`eter when the pressure is relieved, so that there is no
`undue restriction when the valve is in the open posi
`tion.
`,The stent is arranged so that the arms remote from
`the apexes act as torsion bars as the deflection takes
`place, while the apexes themselves experience little dis
`tortion. Various arrangements may be included to
`stiffen the bars as may be required to obtain the proper
`degree of resiliency in the stent. The stiffening arrange
`ments may include additional elements interconnecting
`the upper and lower bars of the stent.
`A noncorrosive metal, such as stainless steel, may be
`used in constructing the stent, or it may be made of
`plastic. In either event, it is preferable that it be possi
`ble to deflect the arms permanently in order to vary the
`lateral dimensions of the stent so that it can be adjusted
`to ?t a particular heart valve to be applied to it. This
`may be accomplished by exceeding the yield point of
`the metal stent, or through the use of heat or solvents
`in bending the plastic. In either event, however, the
`stent retains its resilience after the adjustment.
`For a plastic stent, a reinforcing ring may be provided
`at the exterior of the end of the stent remote from the
`apexes, the ring being ?tted loosely in a notch having
`
`60
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`65
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`30
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`BRIEF DESCRIPTION OF THE DRAWINGS:
`FIG. I is a perspective view, partially broken away,
`illustrating a heart valve mounted on a stent in accor
`dance with this invention;
`FIG. 2 is an enlarged perspective view of the stent;
`FIG. 3 is a side elevational view of the stent, illustrat
`ing the manner in which the stent de?ects under load;
`FIG. 4 is a top plan view of the arrangement of FIG.
`3;
`FIG. 5 is an enlarged fragmentary perspective view
`showing the attachment of the heart valve and cloth el»
`ements to the stent;
`FIG. 6 is a perspective view of a stent having addi
`tional members for controlling the deflection of the
`upper arms;
`FIG. 7 is a perspective view of a stent having a differ
`ent arrangement of the members to control the de?ec
`tion of the upper arms;
`FIG. 8 is a perspective view of a modi?ed form of the
`stent also controlling the de?ection of the upper arms;
`FIG. 9 is an enlarged-fragmentary sectional view il
`lustrating the arrangement for reinforcing the base of
`the stent when made from plastic;
`FIG. 10 is a view similar to FIG. 5, but with a differ
`ent arrangement of the cloth covering elements;
`FIG. 11 is a view similar to FIGS. 5 and 110, but with
`the addition of a ?ap at the base of the stent for attach
`ment to the heart; and
`FIG. I2 is a perspective view of a stent of a different
`con?guration.
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`The stent 10 illustrated in FIGS. 1-4 is of a basic
`shape for use in the aortic, mitral, tricuspid or pulmo
`nary location. The stent 110 is an annular framework,
`circular in plan, made of a material which is both non
`corrosive and resilient. Suitably, it may be constructed
`of a stainless steel, such as that marketed under the
`
`NORRED EXHIBIT 2100 - Page 5
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`

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`
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`30
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`3
`trademark “Elgiloy" by Elgiloy Company, 853 Dundee
`Ave, Elgin, 111. 60120. A resilient plastic, such as poly
`propylene, also may be used for the stent 10.
`The stent 10 includes three apical portions 11, 12
`and 13 at one end of the annular framework, which are
`of generally oval shape so that they present rounded
`upper surfaces. Openings 14, 15 and 16 may be pro
`vided through the apical portions 11, 12 and 13. The
`apical portions 11, 12 and 13 are for supporting the
`commissures of a heart valve 18, which may be from a
`human or from an animal. Particularly when the stent
`is intended to receive an animal valve, the apical por
`tions are not distributed equally around the perimeter
`of the stent 10. In the example shown, there is equal an
`gular spacing between the apical portions 11 and 12
`and between the apexes 11 and 13. However, the spac
`ing between the apical portions 12 and 13 is approxi
`mately 17-33 percent under the spacing of the other
`apexes, preferably around 20-25 percent less. This is in
`order that the stent will conform to the spacing of the
`commissures of the valve 18 to be applied to it, which
`for animals is very close to this proportioning. Alterna
`tive spacing of the apexes is such that, if one space be
`tween adjacent apexes is a reference, a second is
`around 4-10 percent less than the reference space, and
`the third is about l7-33 percent less than the reference
`space.
`Extending between the lower portions of the apical
`parts 11, 12 and 13 of the stent 10 are support arms 19,
`20 and 21. These arms are scalloped, being curved
`away from the apical portions 11, 12 and 13 so that
`they are concave toward the end of the stent where the
`apexes are located. lmmediately beneath the apexes
`11, 12 and 13 are short depending posts 22, 23 and 24,
`respectively, which are approximately parallel to the
`axis of the stent 10. Lower support arms 25, 26 and 27
`interconnect the bottom ends of the posts 22, 23 and
`24. The arms 25, 26 and 27 may fall substantially in a
`radial plane through the stent, collectively forming a
`ring, or they may be scalloped generally as are the arms
`19, 20 and 21. However, when scalloped, the lower
`arms 25, 26 and 27 are not scalloped as deeply as are
`the upper arms. The lower arms 25, 26 and 27 are sub
`stantially the same distance from the axis of the stent
`as are the upper arms 19, 20 and 21.
`Prior to attaching the valve 18 to the stent 10, a felt
`packing or jacket 28 is applied around each of the
`apexes 11, 12 and 13, extending downwardly also to
`encompass the support posts 22, 23 and 24 and the im
`mediately adjacent portions of the lower arms 25, 26
`and 27. The felt jackets 28 cover both the inner and
`outer surfaces of the stent. After this, a sleeve 29,
`which may be of woven material or felt, or of sponge,
`is applied to the stent 10. The cloth sleeve 29 is annular
`and contoured so that it fits over the apical portions 1 1,
`12 and 13 and the felt packing 28, providing inner and
`outer layers along the inner and outer surfaces of the
`stent. The outer layer of the cloth sleeve 29 is stitched
`together around the perimeter of the stent to provide
`a bead 30. A ring 31 of felt or sponge may be received
`within the bead 30. The bead 30 and ring 31 provide
`a location for suturing when the valve is grafted in the
`heart, enabling a hemodynamic seal to be obtained.
`After applying the cloth sleeve 29 to the stent 10, the
`valve 18 is positioned on the stent, with the valve com
`missures at the apexes 11, 12 and 13, while the margins
`of the cusps conform to the scalloped con?guration of
`
`41
`the support arms 19, 20 and 21. The presence of the
`various apexes and support arms assures that there is a
`portion of the stent conforming to the shape of the
`valve 18 available for secure attachment of all periph
`eral parts of the valve. The arcuate upper configuration
`of the apexes ll, 12 and 13 allows angular latitude in
`the positioning of the valve commissures. There are
`some dimensional differences among all natural valves,
`so that the spacing of the commissures may vary to a
`degree. With the upper portions of the apexes 11, 12
`and 13 being arcuate, valves of different proportions
`may be accommodated and allowed to assume their
`natural contour while still being afforded ready and ap
`propriate locations for attachment.
`While being made of resilient material, the stent 10
`may be given a permanent de?ection, which is impor
`tant in adapting the stent to conform to the contour of
`the particular heart valve being applied to it. The per
`manent de?ection for a metal stent is achieved by man
`ually deforming the arms 19, 20 and 21 beyond the
`yield point, while, for plastic stents, the application of
`heat or solvents may be necessary. Because of the seal
`loped con?guration, bending of the support arms 19,
`20 and 21 upwardly as the stent is shown causes an in
`crease in the effective diameter of the stent. This is in
`dicated in phantom in the left-hand portion of FIG. 3.
`Conversely, downward deflection of the support arms
`reduces the stent diameter. Permanent de?ection of
`the arms 19, 20 and 21, therefore, allows the shape of
`the stent to be adjusted as needed. The resilience of the
`stent 10, however, is retained, irrespective of whether
`or not the arms 19, 20 and 21 are given a permanent
`de?ection.
`After the valve 18 has been applied to the stent 10,
`an additional annular reinforcing ring of cloth or
`sponge 33 is applied to the scalloped end of the stent
`10, extending entirely around the perimeter of the
`stent. The outer margin of the ring 33 is tucked under
`the upper edge of the outer layer of the sleeve 29.
`Sutures 34extend through the cloth ring 33, the edge
`of the outer layer of the sleeve 29 and the tissue of the
`valve 18, holding the assembly on the stent 10. The
`cloth ring 33 acts as a reinforcement for the suture line,
`distributing the load on the sutures. Without the cloth
`ring 33, there is some tendency for the loops of the su
`tures to pull through the tissue of the valve 18. How
`ever, the loops of the sutures 34 bear against the rein
`forcing ring 33 and will not cut the valve tissue.
`The felt packing around the apexes 11, 12 and 13
`provides a soft bed and padding that protects the su
`tures and the cloth 29 as well. Otherwise, there can be
`some abrasion of the sutures and the cloth on the rela
`tively hard stent surface.
`This completes the preparation of the heart valve,
`which may be stored at this point, ready for implanta
`tion. With the stent 10 being entirely covered by cloth,
`there is no exposure of the metal or plastic of the stent
`in the portions of the heart where clotting is a problem.
`Only tissue is exposed in the critical areas, so any ten
`dency to clot is minimized.
`An important advantage is realized from the resil
`ience of the stent 10. Because of this, the stent 10 can
`de?ect in response to hemodynamic pressure on the
`valve 18 during diastole after grafting in the heart of a
`patient. This, in turn, significantly reduces the tensile
`stress in the valve commissures, as a result of which the
`valve is more reliable and the risk to the patient is mini
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`5
`mized. The nature of the de?ection experienced by the
`stent is indicated in phantom in the right-hand portion
`of FIG. 3, as well as being shown in FIG. 4. The apexes
`ll, 12 and 13 are de?ected inwardly by the forces im
`posed on the stent, pivoting about their lower portions
`as the movement takes place. During this de?ection,
`the lower support arms 25, 26 and 27 act as torsion
`bars, twisting to allow the de?ection of the apexes to
`occur. As the lower arms twist and the apexes bend in
`wardly, the upper arms also experience de?ection. The
`apexes themselves are relatively rigid so that they do
`not bend appreciably, with the support arms being pro
`portioned so that they will experience practically all of
`the distortion which takes place. The inward de?ection
`of the apexes Ill, I2 and 13 reduces their spacing from
`the central axis of the stent, giving the stent a shape
`such that less tensile stress is imposed on the valve
`cusps. This is because the supports for the valve cusps
`are moved closer together by the de?ection, which can
`be shown mathematically to result in reduced loading
`on the cusps. With the apexes II, 12 and 13 de?ected
`inwardly, the cusps can assume a more natural and re
`laxed position during diastole. Also, energy is absorbed
`in de?ecting the apexes, resulting in a damping effect
`that reduces the tensile stress in the valve tissue. While
`relieving the stress in the valve 18, the resilience of the
`stent also allows the apexes to return to their normal
`positions when the pressure is relieved. Consequently,
`the apexes do not remain in their inward positions
`‘ where they extend into the valve passageway, and the
`valve can assume a full-open position without imposing
`an obstruction to the ?ow through it.
`Experiments have established that, if the apexes are
`permitted to de?ect approximately two millimeters in
`an average size human valve, the tensile stress in the
`commissures of the valve at the margin of attachment
`is reduced by approximately 20 percent compared with
`that experienced on a rigid stent. This is a signi?cant
`factor in assuring the proper functioning of the valve
`over a long period of time. Of course, the stent must be
`proportioned so that the proper amount of de?ection
`will occur under the hemodynamic pressure exerted,
`which typically is around 2.3 psi.
`The stent may be modified as indicated in FIG. 6 by
`the inclusion of a pair of diagonal bars 36 and 37 posiv
`tioned with one on either side of each of the support
`posts 22, 23 and 241. These diagonal bars stiffen the
`upper arms 19, 2t) and‘ 21 for controlling their de?ec
`tion during preparation of the stent. This is to avoid
`bending the arms when the cloth sleeve 29 is attached
`so that the upper and lower arms are not brought into
`interengagement.
`The stent of FIG. 7 is similar to that of FIGS. 1-4, but
`with the addition of intermediate posts 38, 39 and 40
`between the upper arms I19, 20 and 2K and the lower
`arms 25, 26 and 27, respectively. The intermediate
`posts 38, 39 and 60 connect at the centers of the upper
`arms, stiffening them when it is desired to reduce the
`amount of de?ection permitted.
`In the stent 42 of FIG. 8, the straight posts beneath
`the apical portions are eliminated. Instead, the stent is
`provided with diagonal bars 43 and 44 beneath each of
`the apexes 45, 46 and 47. The latter elements are inte
`gral with the upper arms 48, 49 and 50, and open at
`their bottom ends because of the absence of the verti
`cal posts beneath them. The diagonal posts 43 and 44
`not only connect the upper arms 48, 49 and 50 with the
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`NORRED EXHIBIT 2100 - Page 7
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`lower arms 51, 52 and ‘53, but also serve to control the
`de?ection of the upper arms.
`FIG. 9 illustrates a fragmentary section of a plastic
`stent provided with an annular recess ‘at its lower cor
`ner, which receives a metal reinforcing ring 55. The re
`cess is de?ned by a radial upper wall 56 and a frusto
`conical inner wall 57, which tapers toward the end of
`the stent remote from the apexes. The ring 55, ?tting
`loosely in the recess in the bottom end of the stent,
`stiffens and reinforces the plastic stent at that location.
`The surface 57 is tapered so that there will be no inter~
`ference to inward de?ection of the post 58 when the
`stent de?ects under load. Therefore, the ring 55 will
`not interfere with full ?exing of the stent. It will, how
`ever, keep the adjacent portion of the stent in a circular
`shape when thetdeflection takes place, so that the stent
`does not become unduly distorted.
`The arrangement of FIG. 10 is similar to that of FIG.
`5, but illustrates a variation in the attachment of the re
`inforcing ring at the scalloped end of the stent. Here,
`the annular member 60 of cloth or sponge extends over
`the upper edge of the cloth sleeve 29, rather than being
`tucked under the outer layer of the sleeve 29. The
`edges of the reinforcing ring 60 are doubled under so
`that the ring 60 is in two layers with no exposed edges.
`Again, the elements attached to the stent 10 are held
`in place by sutures. The overlapping of the annular ring
`60 over the outside layer of the sleeve 29 provides the
`assembly with a smoother and neater appearance.
`Another variation is shown in FIG. 11 in which the
`cloth sleeve 6ll is similar to the cloth sleeve 29 de
`scribed above. In addition, however, the sleeve 61 is
`provided with a ?at, doubled-over, annular extension
`or ?ap 62 around the exterior of the stent adjacent the
`lower arms 25, 26 and 27. The cloth extension 62 pro
`vides arhernodynamic seal when‘ grafted in the heart, as
`well as a’ suitable bed over which tissuecan be affixed
`or ingrown. This version is for use in the mitral posi
`tion. No rigid reinforcement is included with the annu
`lar element 62, although felt or sponge‘ may be pro
`vided between its layers.
`The stent 64 of FIG. 12 preferably is made of plastic
`for full flexibility of its apexes 65, 66 and 67. The base
`ring 68 serves as the means to connect the apexes, as
`well as acting as a torsion bar and annular stiffener.
`Cloth maybe used to cover the stent 66, generally as
`described above, and the heart valve 16 may be sutured
`to the cloth when mounted on the stent. Instead of an
`animal or human heart valve, however, other tissue,
`such as fascia lata or pericardium, may be affixed to the
`stent to create valve cusps. For such purposes, the
`apexes 65, 66 and 67 may be equally spaced. A stiff
`ener ring 55 may be employed with the stent 64 to rein
`force the base ring 66.
`The foregoing detailed description is to be clearly un
`derstood as given by way of illustration and example
`only, the spirit and scope of this invention being limited
`solely by the appended claims.
`What is claimed is:
`l. A stent for a heart valve comprising
`a framework of annular con?guration,
`said framework including spaced apical portions
`extending around the longitudinal axis thereof
`and arms interconnecting said apical portions,
`for thereby providing an attachment for the com
`missures and cusps of a heart valve,
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`said framework including means for permitting
`substantial resilient de?ection of said apical por
`tions inwardly toward said longitudinal axis of
`said framework such that there is an apical por
`tion so de?ected a distance of at least approxi
`mately 2 millimeters in response to predeter
`mined loading on said apical portions, which
`loading is that produced by hemodynamic pres
`sure of approximately 2.3 psi. when a heart valve
`is mounted on said framework and grafted in the
`heart of a human, and return of said apical por
`tions to the original positions thereof upon the
`removal of said predetermined loading.
`2. A device as recited in claim 1 in which, for said
`means for permitting said resilient de?ection of said
`apical portions, said arms are twistable as torsion bars
`upon the application of said predetermined loading to
`said apical portions.
`3. A device as recited in claim 2 in which said apical
`portions are relatively rigid so as to be substantially un
`distorted upon the application of said predetermined
`loading to said apical portions.
`4. A device as recited in claim 2 in which said frame
`work includes additional arms collectively of annular
`shape, said additional arms being spaced axially from
`said first-mentioned arms and relatively closer to said
`apical portions.
`5. A device as recited in claim 4 in which said addi
`tional arms incline axially away from said apical por
`tions intermediate said apical portions.
`6. A device as recited in claim 5 in which said addi
`tional arms are de?ectable to take a permanent set
`while retaining the resilience thereof for varying the
`distances thereof from the axis of said framework.
`7. A device as recited in claim 6 including in addition
`means interconnecting said ?rst-mentioned arms and
`said additional arms for stiffening said additional arms.
`8. A device as recited in claim 7 in which said means
`interconnecting said ?rst-mentioned arms and said ad
`ditional arms includes members connecting to said ad
`ditional arms at locations angularly spaced from said
`apical portions.
`9. A device as recited in claim 8 in which said mem
`bers are substantially at the midpoints of said ?rst
`mentioned arms and said additional arms.
`10. A device as recited in claim 8 in which said mem
`bers are in pairs, positioned one on either side of each
`of said apical portions.
`11. A device as recited in claim 10 in which said
`members of each pair are divergent toward said addi
`tional arms.
`12. A device as recited in claim 11 in which said
`framework includes a post interconnecting each of said
`apical portions and said first-mentioned arms, each of
`said posts being positioned between said members of
`each of said pairs.
`13. A device as recited in claim 2 in which said
`framework is constructed of a resilient stainless steel
`material.
`14. A device as recited in claim 2 in which said
`framework is constructed of a resilient plastic material.
`15. A device as recited in claim 14 including in addi
`tion a metal ring around the exterior of said framework
`at the end thereof remote from said apical portions for
`reinforcing said framework.
`16. A device as recited in claim 15 in which said
`framework includes an annular groove receiving said
`
`8
`ring, said groove having an inner surface tapering away
`from said apical portions so that said ring will not re
`strict said resilient de?ection of said apical portions.
`17. A heart valve assembly comprising
`a stent,
`said stent including a generally tubular framework
`having spaced apexes at one end and arms inter
`connecting said apexes,
`said apexes being normally spaced a predeter
`mined distance from the longitudinal axis of
`said framework,
`a heart valve on said framework,
`said heart valve having commissures substantially
`at said apexes and cusps having marginal por
`tions adjacent said arms, and
`‘
`means for attaching said heart valve to said frame
`work,
`said framework including means for permitting
`substantial resilient de?ection of said apexes in
`wardly toward said axis a distance of at least ap
`proximately 2 millimeters in response to hemo
`dynamic pressure of approximately 2.3 psi. on
`said heart valve upon grafting of said heart valve
`in a heart, and return of said apexes to said pre~
`determined distance from said axis upon removal
`of said hemodynamic pressure.
`18. A device as recited in claim 17 in which, for said
`means for permitting said resilient de?ection of said
`apical portions, said arms are twistable as torsion bars
`upon the application of said predetermined loading to
`said apical portions.
`19. A device as recited in claim H8 in which said api
`cal portions are relatively rigid so as to be substantially
`undistorted upon the application of said predetermined
`loading to said apical portions.
`20. A device as recited in claim 17 including in addi
`tion a material selected from the group consisting of
`cloth or sponge means entirely covering said frame
`work.
`21. A device as recited in claim 17 including in addi
`tion a first material selected from the group consisting
`of
`cloth or sponge means,
`said material including an annular element extend
`ing over the marginal edge portion of said heart
`valve at said one end,
`said means for attaching said heart valve to said
`framework including sutures,
`said sutures extending through said material and
`said heart valve with loop portions of said sutures
`engaging said material for thereby preventing
`said sutures from pulling through the tissue of
`said heart valve.
`22. A device as recited in claim 21 in which
`said material includes a sleeve entirely receiving said
`framework so as to provide an inner layer and an
`outer layer, and
`including an annular bead on the exterior of said
`outer layer intermediate the ends thereof for pro
`viding a means for attachment to a heart.
`23. A device as recited in claim 22 in which said bead
`is integral with said outer layer, and including a ring of
`a second material selected form the group consisting of
`sponge or felt received in said head.
`24. A device as recited in claim 23 in which said first
`material includes padding between said layers at the lo
`
`35
`
`40
`
`45
`
`55
`
`65
`
`NORRED EXHIBIT 2100 - Page 8
`
`

`
`3,755,823
`
`cations of said apexes for protecting said sutures and
`said layers from being abraded by said framework.
`25. A device as recited in claim 24 in which said pad—
`ding includes a layer of felt on both sides of each of said
`apexes.
`26. A device as recited in claim 17 including in addi
`tion a material selected from the group consisting of
`cloth or sponge means,
`said material including an uninterrupted sleeve en
`tirely receiving said framework so as to provide
`an inner layer and an outer layer, and
`an integral generally ?at uninterrupted annular ?ap
`at the end of said stent opposite from said one
`end for providing a means for attachment to a
`heart.
`27. A heart valve assembly comprising
`a stent,
`said stent including a generally tubular framework
`having spaced apexes at one end and arms inter
`
`l0
`
`15
`
`connecting said apexes,
`said arms being inclined away from said apexes at
`locations intermediate said apexes,
`a heart valve on said framework,
`said heart valve having commissures substantially
`at said apexes and cusps having marginal por
`tions adjacent said arms,
`an annular member of material selected from the
`group consisting of cloth or sponge material overly
`ing the marginal edge portion of said heart valve at
`said one end, and
`sutures extending through said annular member and
`said marginal edge portions for attaching said heart
`valve to said framework,
`said sutures having loop portions engaging said an
`nular member for thereby protecting said heart
`valve from damage by said sutures.
`*
`>i<
`=l<
`*
`*
`
`20
`
`25
`
`35
`
`45
`
`55
`
`60
`
`65
`
`NORRED EXHIBIT 2100 - Page 9