NORRED EXHIBIT 2202 - Page 1
`Medtronic, Inc., Medtronic Vascular, Inc.,
`& Medtronic Corevalve, LLC
`v. Troy R. Norred, M.D.
`Case IPR2014-00111
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`

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`US. Patent
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`April 18, 1978
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`Sheet 1 of 3
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`4,084,268
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`FIG. 1.
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`FIG.2.
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`FIG.3.
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`NORRED EXHIBIT 2202 - Page 2
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`U.S. Patent
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`April 18, 1978 Sheet2of3
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`4,084,268
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`FIG.5.
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`FIG.6.
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`NORRED EXHIBIT 2202 - Page 3
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`US. Patent
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`Apri118, 1978
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`Sheet3 of3
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`4,084,268
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`FIG. 9.
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`3
`7
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`NORRED EXHIBIT 2202 - Page 4
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`PROSTHETIC TISSUE HEART VALVE
`BACKGROUND
`This invention relates to frame mounted, prosthetic
`tissue heart valves, and particularly to improvements in
`the construction of such valves.
`Frame-mounted fascia lata heart valves were used
`clinically by Dr. Marian I. Ionescu and Dr. D. N. Ross
`in 1969. Since that time hundreds of tissue valves made
`of autologous or homologous fascia lata, dura mater, or
`of heterologous pericardium have been implanted. A
`construction of bovine pericardial valves is reported in
`Frame-mounted Tissue Heart Valves: Technique of Con
`struction, Bartels, Holden and Ionescu, Thorax (1974)
`29, 51. As reported in that article, an important factor
`on which the long-term function of these valves de~
`pends is their construction before insertion. This inven
`tion is an improved construction over that described in
`the cited article.
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`SUMMARY OF INVENTION
`This invention is directed to an improved construc
`tion principally in the cloth covering for the valve
`frame or stent by which raw fabric or tissue edges are
`not exposed to the blood stream, particularly at the
`valve inlet, added protection is obtained against the
`frame or stitches tearing through the covering cloth,
`risk of the sewing ring separating from the valve is
`eliminated, the stitches attaching the tissue to the stent
`are covered by cloth, and the thickness of material at
`the annulus is reduced to increase the ratio of valve
`internal diameter to external valve diameter, and there
`fore to internal diameter of the heart annulus receiving
`the valve.
`Accordingly, this invention provides a prosthetic
`tissue heart valve in which a continuation of the pledget
`covers the knots of the threads used to stitch the tissue
`to the stent. This invention also provides a construction
`wherein the interior fabric cover is integral with the
`sewing ring or cuff. Further in accordance with this
`invention several layers of padding are provided along
`the edges of the stent where tearing is most likely and
`cushioning is desirable, yet only three layers of cloth
`add to the thickness of the stent at the bottom portion
`which ?ts in the heart annulus. Moreover, this invention
`provides a novel construction wherein no edges of the
`cloth fabric covering the stent are exposed to the blood
`stream.
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`DESCRIPTION OF DRAWINGS
`FIG. 1 is a perspective view of a completed valve;
`FIG. 2 is a perspective view of the same completed
`valve inverted;
`FIG. 3 is a perspective view of the stent covered with
`cloth and ready to receive the tissue, with the sewing
`ring turned down to show certain construction details;
`FIG. 4 is an exploded perspective view of the ele
`ments used in constructing the cloth covered stent;
`FIG. 5 is a perspective view of the tissue ready to be
`placed on the cloth covered stent of FIG. 3;
`FIG. 6 is a perspective view, partially in section, of
`the valve with portions removed;
`FIG. 7 is a perspective view, partially in section, of a
`portion of a partially assembled valve;
`FIG. 8 is a perspective view, partially in section, of a
`portion of a partially completed valve; and
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`FIG. 9 is a sectional view, through the valve at a post
`of a completed valve.
`Referring to FIG. 4, the valve includes a thin-walled
`stent 2 having an annular base 4 and three equally
`spaced upright posts 6 with scalloped upper edges 8 on
`the stent between posts 6. Throughout this application
`the term upper will be used for convenience to refer to
`the out?ow end of the valve and lower will be used to
`refer to the inflow side, recognizing that the valve may
`not be upright where installed. Also, the term upper
`edge of the stent is used to include the side edges of the
`posts 6. Referring now to FIG. 1 the stent supports a
`tissue valve element 10 which surrounds the stent and
`has three cusps l2, l4, and 16 meeting along their upper
`edge portions in the closed position. The cusps are free
`to separate when the pressure below the valve exceeds
`that above to pass blood through the valve in a known
`manner. The flow of blood is from bottom to top in
`FIG. 1 along the axis 23 of the valve. Applicants refer
`to the article cited above in the application for a more
`complete description of the tissue and its assembly and
`operation.
`A pledget and cover 24 extends down the outside of
`the tissue at each post, and a sewing ring or cuff 26 is
`provided for grafting the prosthetic valve into the heart
`valve annulus using well known surgical procedures.
`Referring again to FIG. 4, the stent may be con
`structed of any of the known materials, suitable for
`cloth covered prosthetic heart valves, titanium or nick
`el-cobalt alloy or Teflon or Delvon plastic being among
`the alternatives available. Its bottom edge 28 preferably
`is slightly scalloped having its high points 30 beneath
`the posts 6. Each post 6 has sewing holes, 32, 34, and 36
`three in the illustrated embodiment, spaced vertically
`near its upper end. Additional sewing holes 38, and 40
`are spaced around the circumference of the base. In the
`illustrated embodiment the base 4 has one sewing hole
`38 at the base of each post and ?ve 40 between adjacent
`posts, but that number can be varied, as can the number
`on the posts.
`The cloth covering preferably is of Dacron velour
`and includes an inner sleeve 42, a three piece outer
`sleeve 44, and three interior post sewing pads 46. The
`inner sleeve originally is of a cylindrical shape with
`scallops 48 removed as shown in FIG. 4, corresponding
`generally with the scallops 8 on the upper edge of the
`stent. The outside diameter of the inner sleeve is about
`the same as the inside diameter of the stent base 4. The
`outer sleeve pieces 44 can advantageously be cut from a
`cylinder of cloth to the shape shown, such that each has
`a post portion 50 with a rounded top 52 and two scal
`loped side edges 54, 56 and a base portion 58 with
`straight side edges 60, 62. The interior post pads 46 are
`each a short length of fabric of the same width as the
`posts 6 and having a rounded top 64.
`Referring to FIGS. 8 and 9, three outer sleeve pieces
`44 are each located on the outside of a respective stent
`post 6 and folded over the scalloped edges 8 and top of
`the stent post terminating at 78 ?ush with the inside
`surface of the stent. The three outer cloth pieces 44 do
`not cover the outside of the stent base 4 between the
`regions of the posts 6 as is evident from the spaces
`shown in FIG. 4, but extend to the seams 96 shown in
`FIG. 3. As best shown in FIG. 9, the bottom edge 66 of
`each outer sleeve piece is folded over the bottom edge
`28 of the stent and then folded back at 70 to form a two
`layer 72, 74 pad at the bottom edge 28 and terminates at
`66 about flush with the outer surface of the stent.
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`NORRED EXHIBIT 2202 - Page 5
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`The three interior post sewing pads 46 are placed
`against the inner surfaces of the respective posts and
`’ cover the three post sewing holes 32, 34 and 36 termi-
`I‘ gnatingpjust below the bottom post hole 36.,The upper
`end. of each post pad is layered over the top of the :post—«
`.as~shown at37 in FIG. 9. ~
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`The innersleeve 42 is located inside thestent and y
`ixwrapped around {the top edge 8 of the stent.,This wrap
`” . linthe post area is shown in FIG. 8 where it can be seen.
`that’ the upper edge .78 of the inner sleeve is doubled
`u back on itself and the double layer folded over the stent
`I to provide two layers 80, 82 of inner sleeve of cloth in
`I addition to thelayer 84 of the outer sleeve cloth cover~
`~
`ingthe edge of thepost, with the top edge-78‘ of the
`. inner cloth sleeve located just above: that 65 of the outer
`I sleeve. The doubled portion 86 of the inner sleeve also
`2 extends a short distance on the outside of the outer
`sleeve piece to provide extra padding -over the outside
`I’ of the posts over the sewing holes32, 34 and 36 and the
`M {upper stent edge 8 where the tissuelt) is located.
`T -
`FIG.,6 shows the arrangement of thecloth cover at I,
`f the portions of the stent base 4. between the outer sleeve
`. pieces 44-..It can beseen that the inner sleeve ‘does not “
`I terminate at the inner end of layer 82in this area‘ but is
`IA again folded back at 88 on itself to provide the third
`‘layer 90 of padding over the stent» edge8 and extends
`7 down to the outer, faceof ‘the stent and is folded in
`double layers 92, 94 across the lower stent edge in the
`same manner as the outer sleeve pieces 72, 74 in FIG. 8.
`Thus, the inner sleeve 42 also serves thefunction of the
`. outer sleeve at the base portions 4 between pieces of the
`outer sleeve 44.
`-The mating side edges of the outer’ sleeve portions
`2' and inner sleeve portions are all tucked in and sewn to
`each other in six seams 96 (FIG. 3). Appropriate other
`stitching of the cloth cover is. also provided toholde the
`cloth in the described position covering the stent. Alter-
`? natively, the outer sleeve portions 44 can be made con-
`tinuousaround the stent using the arrangement of FIG.
`7 allthe way around instead of the arrangement of FIG;
`I6.
`I The bottom end of the inner cloth sleeve 42 extends a
`substantial distance below thebottom of the stent 2 and
`formsan integral annular sewing ring 26»for grafting the
`prosthetic valve to the heart.
`As shown in FIG. 8, the sewingring 26 is formed of
`an inner three layer 98, 100, 102 annular sewing pad 27,
`for example of woven Teflon or Dacron fabric, covered
`by the fabric of the inner sleeve 4-2 which is wrapped
`aroundthe annular sewing pad 27 to provide one layer
`‘ of cloth 104 above the pad 27 and two—layersI106, 108‘
`beneaththe pad, and having its edge. 110 covered by the
`layer of cloth 106. At the inner fold 109Ibetwe‘en layers
`7 104-and 108 a stitch is made to layer 106. AS Shown in
`FIGSQ2 and 3, a. seam 111 was sewn in‘ forming the
`inner sleeve portion into a cylinder. That seam 111
`‘ extends out into thesewing ring 26. When sewing the I
`‘ seam 111 the raw edges of cloth are tucked in so as not
`to be exposed.
`I
`Referring now‘ to FIG. 5, the tissue 10, in the exem-
`I plary embodiment bovine pericardium, is formed into a
`generally‘ cylindrical shape of a diameter to fit over the
`I cloth covered stent 28 as shown in ‘FIG. 3. The top
`portion of thernating tissue edges 11.8, 120 are turned
`out face to face to form an overcaststitched seam 122
`leaving-the bottom portion of that seam 122 temporarily
`institched. The tissue cylinder 10 is placed. around the
`Iccloth covered stent 28 so as to circumscribe the base 4
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`and the posts 6. with the seam 122icenteredI on one post
`6.A pledget and cover 24, as best; shown in FIGS. ,1 and ,
`2, preferably of I Teflon in a forrngnot having fibers“
`which can unra,vel,I is .located—outside. the;tissue~‘ll) at
`each post 6.>Referring now to F;IGS».Ij‘7~ and:.8, each I
`pledget and cover has a sewing 'po_rt'io'n~126. whiohfiays.
`against thetissue and ycontinu_es..to]a cover portion 128 . L.
`which covers .the*—sti!tt:hes as wiIll«be descriized be,low.I I1
`Theatissue 10 andpledgetilfzfi.areattached to} the stent
`I
`using stitches» through the; upper ho1es:32, 34{a'r1d‘36;in
`each post, and through the sewing portion 126 ‘/of ‘the,
`pledget. Small wedges 124, 130, and ’132:are cut from ’
`the bottom portionof the tissue at: the.th’ree.po‘sts 6’to
`provide relief to permit the tissue to close: in cusps. The I
`tissue valve is tucked around eachindividual postfiby .
`stitches 134 as shown in FIG. 6.,Th_is causes the tissue
`valve to close in three cusps 12,, l‘41a’nd716 as shownin _
`FIGS.’ 1 and 2. Each end, 136, ;and,~11$7,of the ‘thread’
`extends from the tuck stitch. 134 through ; the inner.
`sleeve, the inner post sewing pad, the upper hole in Ithe‘
`stent, three layers of clothin the outside of thepost, the ..
`tissue outside the post,fand the sewing portion ofthe“
`pledgetand are tiedoff as shown .ar13s.in FIG. 7.'The .
`pledget and cover 24 is not shown in FIG. 6 in aorderto
`more clearly show the other details.
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`The tissue is sewn tothe cloth coveredfstent with
`stitches 138 through theholes I38, 40 inthe base and the
`I wedges A124, 130,Iand I132'are sewn. together as dartsgin
`each instance tying off the thfreadzknotshetween the V
`pledgetcover 128 and the piedget sewing portion 126 at
`each post. The cover portion 128 of the: pledget is
`folded down against',,and stitched to,'fthe;sewing portion
`126 to cover the knots. Thevsewing ring 26.7is attached to L
`the stent cover at two places 139 and 141 as shown .in*»
`FIG. 9. Eachset or stitches .139Iand, 141I.continues all
`around the circumference of the sewing ring for solid I
`attachment. It will be noted thatft'he' lower edges .140.
`and 142 of the pledget are coveredbry the‘: sewing ring .
`2.6, but they extend downfar enough only to barely be I
`covered by the sewing ring but not.far,er1ough to add to
`the exterior diameter at the bottom edge of the ‘stent.
`Accordingly, it can beseen that this iconsniuction, uses 1
`the pledget to. cover all knots thereby eliminating any .
`problems I otherwise encountered . from the hanging
`threads. The sewingring is internal cwiththe valve body
`cover to reduce risk of separation.IAll cut cloth. edges of
`the Dacron cloth covering are covered by cloth leaving _
`no exposed raw edges; for possible unravelling. The
`bottom or inlet edgeof the tissue also is covered; The
`onlyedges exposed. are theside edgesvof .Ithe.Teflon «
`pledget and cover which are well outof the main blood
`flow and preferably are of.a‘Teflon material which will
`not unravel, and the upperedgesof the tissue Wl'liC11’_3»I‘¢3rk‘
`pointed -in the direction. of flow.
`Three layers ofxclothepadding areprovided onboth «
`thebottom and top edges of the stent and also overxthe ;
`outside face of the stent near the topedge wherethe.
`tissue wraps around the stent. Three layers of cloth’ also ‘
`are provided’ between thetissue and the outside of each
`postin the area where the tissueis sewn to the post, and
`two layers are provided. inside the post in that area.
`Those multiple layers provide padding.‘ between the
`tissue and the stent atthe edgewhere the tissue? might; .
`otherwise be damaged. Yet the ratio, of inside diameter
`to outside diameter of the stent is ‘very favorable be- <
`cause at the portion 143 which fits inthe heart» annulus,
`ie. that portion beneath the sewing ring, there are only
`three layers of cloth plus the:tissue«.and stent adding to
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`NORRED EXHIBIT 2202 - Page 6
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`4,084,268
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`the valve thickness. All of this as well as the other fea
`tures expressed or inherent from the above discussion
`provide an improved valve construction well suited for
`commercial production.
`What is claimed is:
`1. A prosthetic heart valve comprising:
`a stent having an annular base and upright posts;
`tissue valve means circumscribing said stent posts;
`thread extending through said tissue stitching said
`tissue to said posts, said thread being twisted into
`knots outside the tissue;
`a ?rst layer of fabric extending along each said post
`outside said tissue;
`said thread also stitching said ?rst layer to said posts;
`a second layer of fabric covering said knots which are
`located between said ?rst and second layers; and
`said ?rst and second layers of fabric being a narrow
`pledget strip which is integral and continuous and
`folded back on itself over the knots.
`2. A prosthetic heart valve in accordance with claim
`1 and further comprising:
`cloth fabric covering said post between said post and
`said tissue.
`3. A prosthetic heart valve in accordance with claim
`1 wherein:
`said tissue is formed generally in a cylindrical shape
`circumscribing the posts of said stent as a group
`and is tacked around each individual post to form
`cusps for closing the valve passage.
`4. A cloth covered stent for a prosthetic heart valve
`comprising:
`a stent having an annular base and plural upright
`posts;
`cloth fabric covering the interior surface of said stent;
`cloth fabric covering the exterior surface of said
`stent;
`a cylindrical tissue valve circumscribing said stent
`posts and said exterior cloth fabric;
`said interior fabric being tightly wrapped around the
`bottom edge of said stent covering the bottom edge
`of said exterior fabric, and preventing loose cloth at
`the bottom edge.
`5. A cloth covered stent in accordance with claim 4
`and further comprising:
`said interior fabric where wrapped around the bot
`tom edge of said stent extending over the bottom
`edge of said tissue valve to cover said edge, and
`forming an integral annular sewing ring for graft
`ing the stent onto a heart annulus.
`6. A stent in accordance with claim 5 and said sewing
`ring further comprising:
`an annular fabric pad circumscribing the stent base;
`said interior fabric extending from its wrap around
`the bottom edge of the stent to wrap around the
`fabric pad and terminating in an edge adjacent said
`pad entirely covered by a layer of its own fabric.
`7. A stent in accordance with claim 4 wherein:
`said bottom edge of the exterior fabric is doubled
`over the bottom edge of the stent to form two
`60
`layers of cloth cover tight against said bottom edge
`in addition to the layer of the covering interior
`fabric.
`8. A stent in accordance with claim 4 wherein:
`said interior and exterior fabrics are folded tightly
`over the top edge of said stent to form three layers
`of cloth covering over said edge.
`9. A stent in accordance with claim 8 wherein:
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`said fabric is folded over the outer surface of the stent
`adjacent its top edge to formthree layers of cloth
`on said outer surface adjacent the top edge.
`10. A stent in accordance with claim 4 wherein:
`at least partway around the stent the interior and
`exterior fabric are integral.
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`11. A stent in accordance with claim 4 wherein:
`said fabric is folded around the posts of said stent to
`form three layers of fabric on the outside of each
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`post.
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`12. A stent in accordance with claim 4 and further
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`comprising:
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`a second layer of fabric on the interior of said posts.
`13. A cloth covered stent for a prosthetic heart valve
`comprising:
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`a thin-walled stent having an annular base and plural
`upright posts, said stent having upper and lower
`edges;
`a layer of cloth fabric covering the exterior surface of
`said stent;
`a cylindrical tissue valve circumscribing said stent
`and said exterior fabric;
`a layer of cloth fabric covering the interior surface of
`said stent;
`three layers of cloth fabric tightly wrapped over and
`covering the upper edge of said stent;
`three layers of cloth fabric tightly wrapped over and
`covering the lower edge of said stent;
`the bottom portion of the stent base which ?ts in the
`heart annulus having only one layer of cloth cover
`ing the interior and only two layers covering the
`exterior; and
`said fabric having no edges exposed.
`14. A prosthetic heart valve comprising:
`a thin-walled, rigid stent having an annular base and
`three equally spaced upright posts extending axi
`ally from said base;
`the upper edge of said stent being scalloped in a
`smooth curve between said posts;
`the bottom edge of said stent being scalloped with the
`high points on the scallops beneath the respective
`posts;
`said stent base having a plurality of holes there
`through spaced around its circumference;
`each said stent post having a plurality of holes there
`through spaced along its length;
`three pieces of exterior Dacron velour fabric each
`covering the exterior of a post and of the base
`adjacent the post;
`each of said three pieces of exterior fabric being
`wrapped over the upper edge of the stent in a single
`layer and being folded over the bottom edge of the
`stent in a double layer;
`an interior Dacron velour fabric covering the interior
`surface of the stent;
`said interior fabric being folded over the top edge of
`the stent in a double layer where covered by the
`interior fabric;
`said interior fabric being folded over the top edge of
`the stent in a triple layer and also extending down
`to cover the exterior surface of the stent base
`where not covered by the exterior fabric and termi
`nating in a double fold over the bottom edge of the
`stent base;
`the portion of the interior fabric folded over the
`upper edge of the stent also providing second and
`third layers of fabric on the exterior of the stent
`posts over the holes through the posts and along
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`NORRED EXHIBIT 2202 - Page 7
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`4,084,268
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`the outer surface of the stent adjacent its upper
`edge;
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`, a fabric sewing pad between the interior surface of
`each post at the holes through the post and interior
`fabric;
`a generally cylindrical, valve element of bovine peri»
`cardium tissue circumscribing the stent and fabric
`cover;
`' stitches tacking the tissue around each, post causing
`' the tissue normally to close in three cusps;
`a Te?on fabric piedget strip outside the tissue at each .
`'post, each said pledget strip including a?rst layer
`adjacent said tissue and a second layer outside ?rst
`‘layer, said layers being integrally formed by a fold
`at the upper end and being stitched together along
`their long edges;
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`thread stitches attaching said tissue to said stent ‘
`through the holes therethrough, allof said thread
`stitches being knotted between the two layers of,
`said pledget;
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`the bottom of said interior fabric ‘being, wrapped over
`said double layer of fabric on‘ the bottom edge, of ,
`the stent and extending outward and?upward to
`form an integral sewing ring;
`the sewing ring having an annular three layered‘ pad
`of Teflon fabrie'covered by two layers‘of the'inte-r
`rior fabric on the underside and a single layer on
`the upper side, the edge of said inner fabric being '
`on the inner layer of the two underside layers and!
`covered‘ by the outer layer‘of said twolayers; and
`said sewing ring being sewn to said tissue and cover
`ing the bottom edges of the pledget.
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