`Leonhardt et al.
`
`I 1111111111111111 11111 lllll lllll lllll 111111111111111 lllll 111111111111111111
`US005957949A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,957,949
`Sep.28,1999
`
`[54] PERCUTANEOUS PLACEMENT VALVE
`STENT
`
`[75]
`
`Inventors: Howard J. Leonhardt; Trevor
`Greenan, both of Sunrise, Fla.
`
`Primary Examiner-Michael Powell Buiz
`Assistant Examiner-Daphna Shai
`Attorney, Agent, or Firm-Paul F. Bawel
`
`[57]
`
`ABSTRACT
`
`[73] Assignee: World Medical Manufacturing Corp.,
`Sunrise, Fla.
`
`[21] Appl. No.: 08/848,892
`
`[22] Filed:
`
`May 1, 1997
`
`Int. Cl.6
`.................................................... A61M 29/00
`[51]
`[52] U.S. Cl. .......................... 606/194; 606/108; 606/195;
`606/198; 623/1; 623/2; 623/12
`[58] Field of Search ..................................... 606/108, 194,
`606/195, 198, 200; 623/1, 2, 12
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,733,665
`5,163,953
`5,411,552
`5,591,195
`5,665,103
`5,667,523
`
`3/1988 Palmaz .................................... 606/108
`11/1992 Vince .......................................... 623/2
`5/1995 Andersen et al.
`.......................... 623/2
`1/1997 Taheri et al. ............................ 606/194
`9/1997 Lafontaine et al.
`.................... 606/194
`9/1997 Bynon et al. ........................... 606/194
`
`An artificial valve stent for maintaining patent one way flow
`within a biological passage is disclosed. The artificial valve
`includes a tubular graft having radially compressible annular
`spring portions for biasing proximal and distal ends of the
`graft into conforming fixed engagement with the interior
`surface of a generally tubular passage. Also disclosed is a
`deployment catheter including an inner catheter having a
`nitinol core wire, a controllable tip balloon at its the distal
`end for dilation and occlusion of the passage, and a con(cid:173)
`trollable graft balloon in the vicinity of and proximal to the
`tip balloon for fixedly seating the spring portions in con(cid:173)
`formance with the interior surface of the passage. A spool
`apparatus for adjusting or removing an improperly placed or
`functioning artificial valve, and a microembolic filter tube
`are usable with the deployment catheter. The artificial valve
`may be completely sealed to the living tissue by light
`activated biocompatible tissue adhesive between the outside
`of the tubular graft and the living tissue. A method of
`implanting the artificial valve is also disclosed.
`
`17 Claims, 8 Drawing Sheets
`
`68
`
`22
`
`46
`
`46
`
`Medtronic Exhibit 1006
`Medtronic Corevalve v. Colibri Heart Valve
`IPR2020-01454
`Page 00001
`
`
`
`U.S. Patent
`US. Patent
`
`Sep.28,1999
`Sep.28, 1999
`
`Sheet 1 of 8
`Sheet 1 0f8
`
`5,957,949
`5,957,949
`
`co
`.,._
`.
`(!)
`0:
`
`W26FIG.1AFIG.1C
`
`(!)
`0:
`
`IPR2020-01454 Page 00002
`
`IPR2020-01454 Page 00002
`
`
`
`U.S. Patent
`
`Sep.28,1999
`
`Sheet 2 of 8
`
`5,957,949
`
`FIG.2
`
`24
`
`22
`
`FIG. 4
`
`FIG. 3
`
`IPR2020-01454 Page 00003
`
`
`
`"'-' \0
`\0
`....
`.....:a
`Ul
`\0
`....
`Ul
`
`5,957,949
`
`~
`
`0 ....,
`~ ....
`'JJ. =(cid:173)~
`
`Sheet 3 0f8
`
`CIO
`
`\0
`\0
`'"""'
`\0
`~CIO
`N
`~ '?
`'JJ.
`
`Sep.28, 1999
`
`~ = ......
`~ ......
`~
`•
`r:JJ.
`d •
`
`US. Patent
`
`152
`
`" ~,
`
`0 136
`
`FIG. 5
`
`' ····162
`
`.., .. 4
`
`108
`
`FIG.5
`
`,--,--100
`
`/
`
`IPR2020-01454 Page 00004
`
`IPR2020-01454 Page 00004
`
`
`
`U.S. Patent
`
`Sep.28,1999
`
`Sheet 4 of 8
`
`5,957,949
`
`100 r
`
`
`
`126
`
`Fig. 6
`
`000000000000000000000
`
`IPR2020-01454 Page 00005
`
`
`
`U.S. Patent
`US. Patent
`
`Sep.28,1999
`Sep.28, 1999
`
`Sheet 5 of 8
`Sheet 5 0f8
`
`5,957,949
`5,957,949
`
`FIG. 7B
`
`180
`
`176---..
`
`
`
`106
`
`172
`
`112
`
`FIG. 7A
`
`IPR2020-01454 Page 00006
`
`IPR2020-01454 Page 00006
`
`
`
`U.S. Patent
`US. Patent
`
`Sep.28,1999
`Sep. 28, 1999
`
`Sheet 6 of 8
`Sheet 6 0f 8
`
`5,957,949
`5,957,949
`
`188
`
`184
`
`. .106
`
`--
`
`I!!!“""“‘u"""3“."““‘D“““‘,““"“‘l
`
`,iv4v9.00..’
`
`~ 1 I I • I
`11 I . I • r I > : I
`:-
`
`.. _
`
`FIG. 8
`
`IPR2020-01454 Page 00007
`
`IPR2020-01454 Page 00007
`
`
`
`
`
`U.S. Patent
`US. Patent
`
`Sep.28,1999
`Sep. 28, 1999
`
`Sheet 7 of 8
`Sheet 7 0f 8
`
`5,957,949
`5,957,949
`
`FIG. 9A
`
`
`
`FIG. 9B
`
`IPR2020-01454 Page 00008
`
`IPR2020-01454 Page 00008
`
`
`
`U.S. Patent
`US. Patent
`
`Sep.28,1999
`Sep. 28, 1999
`
`Sheet 8 of 8
`Sheet 8 0f 8
`
`5,957,949
`5,957,949
`
`FIG. 9G
`
`
`
`FIG. 90
`
`IPR2020-01454 Page 00009
`
`IPR2020-01454 Page 00009
`
`
`
`5,957,949
`
`1
`PERCUTANEOUS PLACEMENT VALVE
`STENT
`FIELD OF THE INVENTION
`This invention relates to artificial valves, specifically
`those placed percutaneously by a catheter. The artificial
`valve disclosed may replace existing valves such as are in
`the heart or esophagus, or may be placed where fluid flow
`needs to be maintained in one direction only.
`BACKGROUND OF THE INVENTION
`The disclosed invention involves a percutaneously placed
`artificial valve to maintain bodily fluid flow in a single
`direction. It opens and closes with pressure and/or flow
`changes. The invention may be placed anywhere flow con(cid:173)
`trol is desired. To facilitate the discussion of the disclosure,
`use as a heart valve will be addressed. Heart valves are
`selected because they provide the highest risk to the patient
`during placement, and in terms of lowering the risk while
`providing a superior device the advantages of this valve are
`clearly presented. It is understood that the device and
`method disclosed are available to all valvular needs.
`Cardiac valve prostheses are well known in the treatment
`of heart disease. The normal method of implantation
`requires major surgery during which the patient is placed on
`a heart-lung machine and the patient's heart is stopped. Once 25
`the surgery is complete, the patient can expect an extended
`hospital stay and several more weeks of recuperation. A
`mortality rate of five percent (5%) is common. For some
`patients, surgery is not an option because age or some other
`physical problem prevents them from being able candidates 30
`for surgery due to the inherent dangers and the likelihood of
`death therefrom.
`The valve devices themselves fall into two categories,
`either biological or mechanical. Biological heart valves are
`either homograft (a recent human harvest), allograft (a
`stored human harvest) or xenograft (a stored animal
`harvest). Homografts are rare because of the well known
`problems of locating and matching human donors in both
`tissue type and size. Allografts are also in short supply
`because of lack of donors. Xenografts are common and well 40
`accepted, usually from bovine or porcine donors, and many
`times the actual heart valve from the animal is used. These
`devices may be accompanied by immunological rejection
`from the human body when sutured directly to human tissue
`and require the patient to take anti-rejection drugs which
`suppress the immune system. Generally, the valves are
`treated to reduce the antigenicity of the valve tissue, but the
`effect is to limit the life of the valve to about ten years.
`Mechanical valves may be either a ball valve or a leaflet
`valve having one to three leaflets. One leaflet valve, U.S. 50
`Pat. No. 5,469,868, closely resembles a biological valve
`having three synthetic resin leaflets. Mechanical valves are
`susceptible to clot formation and require the patient to
`maintain a strict regiment of anticoagulant drugs which
`carry their own associated risks. Furthermore, some 55
`mechanical valves are prone to wear leading to failure, and
`some materials for mechanical valves are subject to supply
`problems.
`The majority of these artificial valves require surgery and
`the stopping of the heart as discussed above. During 60
`implantation, the valve must be sewn in place either at the
`natural valve location or at a location adjacent to the natural
`valve. Even new laproscopic techniques, while substantially
`less invasive, require general anesthesia and a heart-lung
`machine. There are artificial valves which claim to have 65
`overcome the problems of implantation of the commonly
`used valves.
`
`2
`Three artificial valves which claim the ability to be placed
`percutaneously comprise the nearest prior art. They are the
`Tietelbaum valve, U.S. Pat. No. 5,332,402; the Pavcnik
`valve, U.S. Pat. No. 5,397,351; and the Andersen valve, U.S.
`5 Pat. No. 5,411,552. Each of these devices allow placement
`by minimally invasive techniques. However, each of the
`devices have disadvantages upon which the disclosed inven(cid:173)
`tion greatly improves.
`The Teitelbaum valve uses nitenol to form each of the two
`10 major elements of the valve. It is a mechanical valve, and as
`such is prone to embolism formation. The two types of
`stoppers, a ball and seat and an umbrella and seat, each
`reduce the passageway diameter through the valve thereby
`reducing the efficiency of blood flow through the valve, and
`15 the efficiency of the cardiovascular system itself. Being of
`two separate components, the movement adds extra com(cid:173)
`plexity leading to wear and improper seating. The abun(cid:173)
`dance of metal in direct contact with the tissue requires a
`hydrophilic coating which may or may not prevent stenosis
`20 in the valve passageway. This valve may only be placed in
`the natural valve's position and not elsewhere in the vascular
`system. Also, the nitenol design proposed requires cooling to
`make it sufficiently compliant to fit within the placement
`catheter. Cooled nitenol does not exhibit sufficient force
`upon warming and reformation of its intended shape to
`maintain a seal between the stent and the tissue. Lastly, both
`elements must be inserted independently of the other requir(cid:173)
`ing multiple delivery catheters.
`The Pavcnik valve is also a mechanical valve of ball and
`seat design. It utilizes a Gienturco stent (U.S. Pat. No.
`4,580,586) capped by a cage to comprise a complex restrain(cid:173)
`ing element for the ball which is difficult to manufacture.
`The restraining element must be attached to the seat by a
`connecting member to maintain the proper distance between
`35 the two. The ball is made of latex which can cause a reaction
`with living tissue. The seat is comprised of two rings, one
`smaller than the other, displaced from each other by nylon
`mesh. Both the seat and the restraining element are stainless
`steel which must be fairly stiff and non-compliant to main(cid:173)
`tain sufficient outward bias thereby severely restricting the
`natural movement of the cardiovascular system at the point
`of implantation. There are multiple joints which must be
`soldered together increasing the potential for joint failure
`and breakage. This device requires hooks to maintain
`45 patency in the tissue, requiring surgery to remove once
`deployed. Repositioning is not possible because of the
`hooks. The balloon must be inserted in a deflated state and
`filled after placement within the cage and seat. The filling
`liquid is a silicone rubber which can have detrimental effects
`on the health of the patient if leaked into the blood stream.
`In whole, this is a complex design which is highly suscep-
`tible to thrombi emboli and improper function over time.
`The Andersen valve comprises a stainless steel stent to
`secure a biological valve. The stent is formed of two or more
`wavy rings sutured to each other with the top loop requiring
`projecting apices to secure the commissural points of the
`valve. The valve claims reduced weight but looses this
`advantage by requiring multiple rings to attain patency
`against the tissue. The device requires a special trisection
`balloon with three or more projecting beads to secure the
`valve within the deployment catheter during placement, and
`the stent does not exert sufficient force against the tissue to
`remain in place without a balloon expanding the stent tightly
`into the tissue wall. The stiffness of stainless steel does not
`comply with the natural movement of the cardiovascular
`system which may lead to stenosis at the implantation point.
`Furthermore, the suture points connecting the multiple rings
`
`IPR2020-01454 Page 00010
`
`
`
`5,957,949
`
`4
`FIG. 7a is a perspective view showing a spool apparatus
`and retrieval means of the present invention.
`FIG. 7b is an enlargement of the circled portion A in FIG.
`7a showing the arrangement of a suture loop connecting the
`invention.
`FIG. 8 is an elevational view showing a micro-embolic
`filter tube of the present condition in its deployed position.
`FIGS. 9a-9d are a series of elevational views depicting a
`method of deploying the valve stent in the mitral valve
`10 position.
`
`5
`
`3
`are subject to movement and wear against each other and
`therefore the sutures or the rings may break at the connecting
`points.
`One drawback of all three of these valves is that none of
`the devices may be removed or repositioned once they are
`expressed from their placement catheter. Any misplacement
`or failure requires major open heart surgery equal to or
`greater than that now required by standard procedures. Many
`patients which receive the valve percutaneously because of
`their intolerance to surgery would face a very uncertain
`outcome from misplacement or failure. Also, none of these
`devices seal to the living tissue at the outside wall of the
`prosthesis. Leaks, and therefore emboli, are likely results
`after implantation.
`The need remains for an artificial heart valve which is 15
`placed percutaneously through a single minimally invasive
`entry point; which will seal at the outside wall of the valve
`with the living tissue of the patient; which may be placed
`percutaneously at any point as well as directly over an
`existing vascular or cardiac valve; which will not cause
`thrombi emboli to form at the valve thereby removing the
`need for anticoagulant drugs; which will comply with the
`natural motion of the tissue to which it is attached; which
`will not cause stenosis; which does not require general
`anesthesia or stopping the heart or using a heart-lung 25
`machine during placement; which will reduce the recupera(cid:173)
`tion time after placement both in and out of the hospital; and
`which may be repositioned or removed after placement in
`the event of such a need.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`FIG. 4 shows the preferred embodiment of valve stent 20,
`comprised of three elements. The three elements are stent
`26, biological valve 22, and graft material 24. FIGS. 3, 5,
`7 A, and 7B illustrate accessories and options associated
`which the preferred embodiment, including the deployment
`catheter 100, the bioadhesive material 56 or bioadhesive
`20 packets 62, the spool apparatus 170, and the microembolic
`filter tube 182.
`For purposes of the disclosed invention and its
`apparatuses, the distal end is the end first inserted into the
`patient and the proximal end is the end last inserted into the
`patient.
`Stent 26 is shown in FIGS. la-le. FIG. la shows stent 26
`formed of a single piece of super elastic wire, preferably
`nitenol wire, with two crimping tubes 50. The crimping
`30 tubes 50 is preferable of the same material as the wire to
`avoid problems which occur when dissimilar materials are in
`electrical contact with each other, however other materials
`known in the art may be used. Stent 26 is in its permanent
`shape, although it has not yet had its two ends attached to
`35 itself to form cylindrical wall 64 (FIG. lC) which will
`support the other elements of valve stent 20. The top and
`bottom portions are substantially symmetrical to each other
`having a zig-zag 40 or wavy form. The preferred embodi(cid:173)
`ment has six ( 6) zig-zags 40 which optimizes its compressed
`40 diameter and outward force, but more or less may be used.
`At each end of stent 26 is a short extension 58 beginning
`another zig or wave. Short extension 58 is to close and attach
`the end to the first zig or wave closest to connecting bar 29.
`Short extension 58 and the portion of stent 26 to which
`45 crimping tubes 50 enclose are substantially parallel to each
`other to facilitate their connection.
`The connection is achieved through a crimping tube 50 as
`shown in FIG. lb, or by permanent adhesives or welding
`which are not shown. As is seen in FIG. le, the crimped
`50 connection is made such that the short extension 58 falls
`substantially within the area of cylinder wall 64 formed
`when the connection is complete.
`FIG. lb shows stent 26 in its completed form with
`crimping tubes 50 crimped. This form creates an imaginary
`55 cylinder 48 which will exert an approximate outward force
`of 350 grams or more at each end. An outward force of 350
`grams at the mitral valve position is sufficient to secure the
`valve stent, however stent 26 may be manufactured with
`more or less outward force to accommodate other placement
`positions. The super elasticity of the material allows it to
`deform to forces exerted on it only at those points experi-
`encing the deforming force. All other points will seek their
`permanent shape. This allows stent 26 to conform to and seal
`against the dramatically different structures occurring within
`65 vessel walls and valve locations with one basic stent shape.
`Stent 26 is a continuous super elastic nitenol wire having
`a distal end and a proximal end. Both the distal end and the
`
`60
`
`SUMMARY OF THE INVENTION
`
`A percutaneously implanted artificial valve maintains
`patent one way flow within a biological passage and
`includes a tubular graft having radially compressible annular
`spring portions for biasing proximal and distal ends of the
`graft into conforming fixed engagement with the interior
`surface of a generally tubular passage. The graft material is
`attached to and encloses the annular spring preventing
`contact between the spring and living tissue. A valve is
`sealingly and permanently attached to the internal tubular
`portion of the valve graft. The artificial valve graft may be
`completely sealed to the living tissue by light activated
`biocompatible tissue adhesive between the outside of the
`tubular graft and the living tissue.
`
`A BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. la is an perspective view of the super elastic spring
`stent in its permanent shape prior to attaching the ends to
`form the cylindrical walls.
`FIG. lb is an perspective view of the super elastic spring
`stent in its permanent shape after attaching the ends to form
`the cylindrical walls.
`FIG. le is a top view of the super elastic spring stent in
`its permanent shape after attaching the ends to form the
`cylindrical walls.
`FIG. 2 is an elevational view of the valve stent fully
`deployed within the mitral valve.
`FIG. 3 is an elevational view of the valve stent fully
`deployed within the aorta above the aortic valve.
`FIG. 4 is a sectional view showing the biological valve
`within the stent.
`FIG. 5 is a perspective view of the deployment means of
`the present invention.
`FIG. 6 is a sectional view thereof taken generally along
`the line 6-6 in FIG. 5.
`
`IPR2020-01454 Page 00011
`
`
`
`5,957,949
`
`5
`proximal end are substantially identical, both forming a
`cylinder wall 64 of six zig-zags 40 or waves. Each end is
`pre-sized in diameter to be approximately thirty percent
`(30%) larger in diameter than the largest diameter of the
`tissue against which the valve stent 20 (FIG. 3) will seal. The 5
`overall length of stent 26 is also pre-sized to be sufficient to
`maintain patency against fluid flow in the vessel or natural
`valve position, as well as completely support the biological
`valve ( or mechanical or synthetic valve) without causing
`valve 22 to suffer prolapse or insufficiency.
`The nitinol wire used to form stent 26 is a super elastic
`straight annealed material formed substantially of titanium
`and nickel. It may be coated with a biocompatible material,
`such as titanium oxide, which will reduce the tissue's
`reaction to the nickel and improve radiopacity. A layer of
`PTFE may also cover stent 26 to reduce the risk of blood
`clotting and corrosion. Furthermore, stent 26 may be treated
`with iridium 192 or other low dose Beta radiation emitting
`material to reduce post-surgical cell proliferation in the
`vessel or valve position. Valve stent 20 may have radio
`opaque markers in predetermined positions to aid in deploy(cid:173)
`ment and placement.
`Each zig-zag 40 or wave is equidistant from the next in its
`set and all are of the same height. The peaks and valleys
`forming the waves are all of a predetermined radius to
`maximize the spring bias and prevent sharp transitions
`which create weak points in stent 26. Once crimped, stent 26
`forms two cylinders, one at each end of stent 26. Each
`cylinder is substantially directly above or below the other
`cylinder.
`The cylinders are spaced a predetermined distance from
`each other by a connecting bar 29 which is the central part
`of the continuous wire from which stent 26 is formed.
`Connecting bar 29 is also biased outward to conform to the
`living tissue so as to minimally disrupt blood or other fluid
`flow, thereby minimizing the possibility of clotting. It is also
`covered by and sutured to graft material 24 (FIG. 4).
`Connecting bar 29 provides torsional stability for valve stent
`20.
`FIG. 2 presents a complete pre-sized valve stent 20 fully
`deployed in the location of mitral valve 14. Also refer to
`FIG. 4 to identify elements in the following discussion.
`Mitral valve 14 has been prepared for deployment by
`valvuloplasty to remove plaque and fistulas if necessary.
`Valve stent 20 comprises a malleable graft material 24
`enclosing deformable self-expanding stent 26 to which a
`biological valve 22 is attached. Stent 26 biases the proximal
`and distal ends of valve stent 20 into conforming and
`sealingly fixed engagement with the tissue of mitral valve 50
`14. The deployed valve stent 20 creates a patent one way
`fluid passageway.
`Graft material 24 is a thin-walled biocompatible, flexible
`and expandable, low-porosity woven fabric, such as poly(cid:173)
`ester or PTFE. It is capable of substantially conforming to 55
`the surface of the living tissue to which stent 26 coerces it.
`Graft material 24, through its low porosity, creates the
`one-way fluid passage when sutured to the cylindrical form
`of stent 26. The middle portion of graft material 24 is tapered
`to a smaller cross-sectional area than its ends to prevent 60
`bunching of the material once placed within the patient.
`Stent 26 is sutured within graft material 24 using poly(cid:173)
`ester suture 60. Prior to sewing, graft material 24 is arranged
`to surround stent 26 and is heat pressed to conform to the
`distal and proximal cylindrical ends of stent 26 using an 65
`arcuate press surface (not shown). The arcuate press surface
`is heated to 150 degrees Fahrenheit and corresponds in
`
`6
`curvature to the distal and proximal ends. A preferred
`stitching pattern involves two generally parallel stitches, one
`on each side of the wire, and a cross-over stitch (not shown)
`around the wire for pulling the stitches together. This
`achieves tight attachment of graft material 24 to stent 26
`thereby preventing substantially all contact between stent 26
`and living tissue. The stitching also will be reliable over the
`life of the patient.
`Where other vessels or passages leave the vessel receiving
`10 valve stent 20 at a placement site, or when valve stent 20
`must flair at one or both ends as is shown in FIG. 2, graft
`material 24 may be cut out between the plurality of disten(cid:173)
`sible fingers 46 formed by zig-zags 40 of stent 26. Disten(cid:173)
`sible fingers 46 form a conical tip when compressed together
`15 which facilitates loading valve stent 20 in the deployment
`catheter (FIG. 5) prior to the procedure and if retrieval after
`deployment is necessary. Valve stent 20 may be placed such
`that other vessels are not blocked by placing distensible
`fingers 46 on either side of the vessel junction. Stent 26 is
`20 pre-sized to open beyond the width of the natural valve
`mouth and will flair sufficiently to conform and seal to the
`tissue.
`Biological valve 22 is preferably a porcine valve treated
`and prepared for use in a human. It has two or more
`25 commissural points 68 as is seen in FIG. 4. Biological valve
`22 is attached to stent 26, to graft material 24, or both with
`sutures 60 or biocompatible adhesive or a combination of
`the two. Biological valve 22 is pre-sized to fit within the
`internal diameter of cylinder 48 formed by stent 26 attached
`30 to graft material 24. Attachment is along biological valve's
`22 commissural points 68 and around its base. Whereas a
`biological valve is preferred, a mechanical valve or a syn(cid:173)
`thetic leaflet valve may also be employed.
`A preferred deployment catheter 100 is illustrated in
`FIGS. 5 and 6. Deployment catheter 100 is generally long
`and tubular permitting percutaneous delivery of valve stent
`20 to the placement site. Deployment catheter 100 has a
`proximal end remaining outside of the patient and a distal
`end which is inserted into the patient. The proximal end
`allows access to a plurality of lumens, syringes, filter tube
`182, spool apparatus 170, and other apparatus as necessary
`for implantation of the disclosed invention. Outer sheath 106
`has an axially extending sheath passage 108 and receives an
`elongated compression spring push rod 112 within sheath
`passage 108. A push rod 112 also has a passage extending
`through its longitudinal axis created by the spring coils.
`Inner catheter 110 is slidably mounted within push rod 112
`passage.
`Outer sheath 106 is made of a low friction and flexible
`material, preferably PTFE. Other suitable materials such as
`polyurethane, silicone, polyethylene may be used instead of
`PTFE. The material is preferably clear to allow inspection of
`valve stent 20 and deployment catheter 100 prior to use.
`The size of outer sheath 106 depends on the size of valve
`stent 20 to be implanted. Common sizes range from 12 FR
`to 20 FR. Collapsing distensible fingers 46 of valve stent 20
`together forms a conical tip which allows for easy loading by
`sliding outer sheath 106 over the tip and on until valve stent
`20 resides within outer sheath 106 and beyond by approxi(cid:173)
`mately five millimeters. The conical tips allow a reduction in
`the profile of valve stent 20 of 2 FR, which allows a smaller
`diameter outer sheath 106 to be used. This results in a
`smaller entry incision and less trauma to the patient's access
`passageway.
`Outer sheath 106 has a side port means 116 near its
`proximal end. Side port means 116 provides access for
`
`35
`
`40
`
`45
`
`IPR2020-01454 Page 00012
`
`
`
`5,957,949
`
`10
`
`7
`transporting fluid, such as heparin or contrast dye, through
`outer sheath 106 passage and into the patient. Side port
`means 116 includes a manually operated valve in fluid
`communication with outer sheath 106 passage through a
`flexible tube adapted to receive suitable fluid injection 5
`means (not shown). Proximal to side port means 116, outer
`sheath 106 has at least one latex-lined homeostasis valve
`(not shown) for forming a fluid seal around push rod 112 to
`prevent blood or other fluid from leaking out of the delivery
`catheter at the proximal end.
`Biological valve 22 should be in an open position when
`valve stent 20 is loaded into outer sheath 106. This reduces
`overall profile and stress on biological valve 22 and its
`attachment to stent 26 and cover material. An open valve 22
`also allows inner catheter 110 to pass through valve 22 prior 15
`to and during deployment with negligible chance of damage
`to the valve 22. Valve stent 20 is loaded either end first into
`outer sheath 106, the correct choice depending upon the
`access path taken and the fluid flow direction at the place(cid:173)
`ment site. After placement, biological valve 22 should open 20
`in the direction of blood flow.
`Inner catheter 110 is longer than either outer sheath 106
`or push rod 112 permitting it to extend beyond outer sheath
`106 and push rod 112 at both ends. Inner catheter 110 may
`be made of 8 FR catheter tubing. As is seen in FIG. 6, inner 25
`catheter 110 comprises an embedded, kink resistant nitinol
`core wire 122, a first inner track 124, a second inner track
`126, and a third inner track 128, all extending lengthwise
`thereof. Referring to FIG. 5, a first end port means 130 for
`transporting fluid to first inner track 124 includes a threaded 30
`adapter 132 for mating with suitable fluid injection means
`(not shown) and communicating with a proximal end of first
`inner track 124 through a flexible tube. A second end port
`means 136 for transporting fluid to second inner track 126
`includes a manually operable valve communicating with the 35
`proximal end of second inner track 126 through a flexible
`tube and adapted to receive a suitable fluid injection means.
`Similarly, a third end port means for transporting fluid to
`third inner track 128 includes a manually operable valve
`communicating with a proximal end of third inner track 128 40
`through a flexible tube and adapted to receive a suitable fluid
`injection means.
`A preferred option of core wire 122 is a gradual tapering
`from a diameter of approximately 0.031 inches at its proxi(cid:173)
`mal end to a diameter of approximately 0.020 inches at its 45
`distal end, with the distal tip of core wire 122 being rounded
`and smooth. This feature provides that the proximal end of
`inner catheter 110 is strong and the distal end of inner
`catheter 110 is less likely to puncture or rupture the access
`passage yet will not deflect significantly under the force of 50
`blood flow. Additional to being kink resistant and strong,
`core wire 122 displays superior torsional rigidity translating
`into substantial rotational equivalence along the entire
`length of core wire 122 when turning inner catheter 110 in
`either direction at the proximal end.
`Second inner track 126 and third inner track 128 com(cid:173)
`municate with balloons at the distal end of inner catheter
`110. Second inner track 126 allows filling and emptying tip
`balloon 152 and third inner track 128 allows filling and
`emptying expansion balloon 154. Expansion balloon 154 is 60
`larger in diameter and shaped according to the placement
`site Tip balloon 152 is essentially round and of necessary
`diameter to block blood flow to the placement site if needed.
`Balloons are preferably polyurethane and act in a calibrated
`pressure compliant manner such that injecting a known 65
`amount of fill fluid into balloons relates to a known expan(cid:173)
`sion in the diameter of balloons. Also, withdrawing a known
`
`55
`
`8
`amount of fill fluid from balloons relates to a known
`contraction in the diameter of balloons. Fill fluid is prefer(cid:173)
`able filtered carbon dioxide because of it radiopacity. Fill
`fluid is injected into second inner track 126 and third inner
`track 128 by separate fluid injection means, respectively.
`Fluid injection means may comprise a transparent volume(cid:173)
`marked syringe with slidable plungers for observably con(cid:173)
`trolling the plenum volume of the syringe filling or emptying
`a balloon.
`Tapered head 156 resides between tip balloon 152 and
`expansion balloon 154. It allows a calm and smooth atrau(cid:173)
`matic transition from the profile of inner catheter 110 to the
`profile of outer sheath 106 or to the profile of microembolic
`filter tube 182 (FIG. 8). Tapered head 156 preferably defines
`a first annular abutment lip 158 arranged to engage the distal
`end of outer sheath 106 which prevents tapered head 156
`from entering outer sheath 106 passage. Tapered head 156
`may contain a second abutment lip (not shown) of slightly
`larger diameter than first abutment lip 158 or a flair from a
`smaller to a larger diameter beginning at the first abutment
`lip 158 for preventing the advancement of the distal end of
`microembolic filter tube 182 when it is being employed.
`Push rod 112 is a metallic compression spring having a
`combination of flexibility and axial compression strength to
`enable it to follow a tortuous path without loosing its ability
`to act as a push rod for exerting force against valve stent 20
`during deployment. Push rod 112 is smaller in diameter than
`outer sheath 106 such that both are independently slidable
`relative to the other. Push rod 112 has an internal path larger
`in diameter than inner catheter 110 such that both are
`independently slidable relative to the other. The distal end of
`push rod 112 defines a plunging seal 162 for stopping fluid
`flow into the deployment catheter 100 proximal to plunging
`seal 162. If spool apparatus 170 (FIG. 7a) is employed,
`either plunging seal 162 must be left out, or suture loops 174