(12) United States Patent
`Shaolian et al.
`
`US006299637B1
`(16) Patent N6.=
`US 6,299,637 B1
`(45) Date of Patent:
`Oct. 9, 2001
`
`(54) TRANSLUMINALLY IMPLANTABLE
`VENOUS VALVE
`
`(76) Inventors: Samuel M. Shaolian, 2315 Arbutus St.,
`NeWport Beach, CA (US) 92660;
`Gerard v0n Ho?'mann, 3 Via Presea,
`Trabuco Canyon, CA (US) 92679
`
`*
`
`Notice:
`
`Sub'ect to an disclaimer, the term of this
`J
`y
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/378,386
`(22) Filed:
`Aug, 20, 1999
`51
`I t C] 7
`(52)
`Ci ...................................................... ..
`(58) Field 0
`""""""""""""""""""""
`
`A61F 2/06
`623/1 24
`24 1 6
`
`(56)
`
`623/21’ 2'12’ 2'14’ 2'13’ 1'25
`References Cited
`
`U-S~ PATENT DOCUMENTS
`2/1990 Lane _
`4 904 254
`4,994,077 * 2/1991 Dobben ............................... .. 623/21
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`9/1996 Bilglcinztila '
`'
`3/1997 Camilli _
`3/1997 Laufer et 8.1..
`10/1998 Quijano et a1. .
`10/1998 Nelson et a1. .
`11/1998 Makower .
`12/1998 Lois '
`1/1999 B 6551 e I et a1
`9/1999 Peeler et aL _
`9/1999 Leohardt et a1_ _
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`5:6O7:465
`5,609,598
`5,824,061
`5,824,071
`5,830,222
`578517232
`5 855 601
`59517502
`5,957,949
`
`FOREIGN PATENT DOCUMENTS
`
`OTHER PUBLICATIONS
`
`Diameter—re?uX relationship in perforating veins of patients
`With varicose veins, Joao Luis Sandri, MD, Fanilda S.
`Barros, MD, Sandra Pontes, MD, Clausio Jacques, MD,
`Sergio X. Salles—Cunha, Ph.D., Journal of Vascular Surgery,
`Nov. 1999, vol. 30, No. 5.
`A multicenter, phase I evaluation of cryopreserved venous
`value allografts for the treatment of chronic deep venous
`insufficiency, Michael C. Dalsing, MD, Seshadri Raju, MD,
`Thomas W. Wake?eld, MD, Syde Taheri, MD, Journal of
`Vascular Surgery, Nov. 1999, vol. 30, No. 5.
`Lessons from the past guide the future: Is history truly
`circular‘), Thomas F. O’Donnell Jr, MD, FACS, Journal of
`Vascular Surgery, Nov. 1999, vol. 30, No. 5.
`The effect of graded Compression elastic Stockings on the
`loWer leg venous system during daily activity, Chad L. Buhs,
`MD, Philip J. Bendick, PhD, John L. Glover, MD, Journal
`of Vascular Surgery, Nov. 1999, vol. 30, No. 5.
`Deep venous thrombosis after precutaneous insertion of
`vena caval ?lters, John Blebea, MD, Ryan Wilson, RVT,
`Peter Waybill, MD, Marsha M. Neurnyer, PVT, Judy S.
`Blebea, MD, Karla M. Anderson, MD, Robert G. Atnip, MD
`Journal Of Vascular Surgery, NOV- 1999, V01- 30, NO- 5
`_
`_
`(Llst Con?rmed 0n mm Page)
`
`Primary Examiner—David H. Willse
`Assistant Examiner—Alvin SteWart
`(74) Attorney, Agent, or Firm—Knobbe, Martens, Olson &
`Bear, LLP
`
`(57)
`
`ABSTRACT
`
`Disclosed is a self-expandable prosthetic venous valve, such
`as for implantation in the deep veins of the leg. The valve is
`mounted in a support structure, such as a self-expandable
`tubular Wire cage. Deployment catheters and methods are
`also disclosed.
`
`0 856 300 A1
`
`8/1998 (EP) .
`
`18 Claims, 4 Drawing Sheets
`
`4/
`
`40
`/44 46
`
`1''
`
`/”‘~1~?"'"'~
`
`20
`
`M
`
`F
`
`1 .
`
`NORRED EXHIBIT 2222 - Page 1
`Medtronic, Inc., Medtronic Vascular, Inc.,
`Medtronic Corevalve, LLC
`v. Troy R. Norred, LLC
`Case IPR2014-00111
`
`

`

`US 6,299,637 B1
`Page 2
`
`OTHER PUBLICATIONS
`
`Sensory Impairment: A feature of chronic venous insuf?
`ciency, Frank T. Padberg Jr, MD, Allen H. Maniker, MD,
`Gwendolyn Carmel, RVT, Peter J. Pappas, MD, Michael B.
`Silva Jr, MD, Robert W. Hobson II, MD, Journal of Vascular
`Surgery, Nov. 1999, vol. 30, No. 5.
`Experimental prosthetic vein valve, Slde A. Taheri, MD,
`Thomas Wormer , MD, Louis LaZar, MD, Julia Cullen, MD,
`Helene Burgio, R.N.,InternationalAngiology vol. 8, No. 1,
`Jan.—Mar. 1989.
`Distribution of valves in the great saphenous vein; its
`clinical implications, Shinohara H, MorisaWa S, Toshima M,
`MiZukami S, Okajiimas FoliaAntJpn, Oct. 1990 (Abstract).
`Sapheno—femoral Valves. Histopathological Observations
`and Diagnostic Approach before Surgery, Leonardo Corcos,
`MD, TiZiana Procacci, MD, Giampiero PeruZZi, MD, Mario
`Dini, MD, Dinno De Anna, MD, Dermatol Surgery, 1996.
`Repair and replacement of deep vain valves in the treatment
`of venous insufficiency, Wilson NM, Rutt DL, BroWse NL,
`BrJ Surg, Apr. 1991 (Abstract).
`Experimental Prosthetic Vein Valve. Long—Term Results,
`Syde A. Taheri, M.D., F.A.C.A., Raymond O. SchultZ, M.D.,
`Angiology, vol. 46, No. 4, Apr. 1995.
`External valvuloplasty of the aspheno—femoral junction,
`Corcos L, PeruZZi GP, Romero V, Procacci T, Zamboni P,
`Dini S, Phlebologie, Apr.—Jun. 1991. (French document).
`Durability of venous valve reconstruction techniques for
`“primary” and postthrombotic re?ux, Raju S, Fredericks
`RK, Neglen PN, Bass JD,J Vasc Surg, Feb. 1996 (Abstract).
`Technical Options in Venous Valve Reconstruction, Seshadri
`Raju, MD, James D. Hardy, MD, The American Journal of
`Surgery, vol. 173, Apr. 1997.
`Reparative surgery of valves in the treatment of super?cial
`venous insuf?ciency. Exetrnal banding valvuloplasty versus
`high ligation or disconnection. A prospective multicentric
`trial, L. Corcos, D. De Anna, P. Zamboni, V. Gasbarro, V.
`Bresadola, T. Procacci, A. Liboni, C. Macchi, I. Donini,
`Journal des Maladies Vasculaires, 1997.
`Clinical results of deep venous valvular repair for chronic
`venous insuf?ciency, William G. Jamieson, MD, FRCS,
`Barbara Chinnick, RN, Can J. Surg. vol. 40, No. 4, Aug.
`1997.
`Tube Collapse and Valve Closure in Ambulatory Venous
`Pressure Regulation; Studies With a Mechanical Model,
`Seshadri Ruju, MD, Austin B. Green, MS, Ruth K. Freder
`icks, MD, Peter N. Neglen, MD, PhD., C. Alexander Hud
`son, MD, Keith Koenig, PhD, J. Endovasc Surg. Feb. 1998.
`Clinical Dynamics of Varicose Disease in Patients With High
`Degree of Venous Re?ux During Conservative Treatment
`and After Surgery: 7—Year FolloW—Up., Fedor Lurie, MD,
`PhD, Nina P. Makarova, MD PhD, International Journal of
`Angiology, May 1998.
`
`Status of Vein Valve Transplant After 12 Months, Syde A.
`Taheri, MD: Louis LaZar, MD; Steven Elias, MD, Arch
`Surg—vol. 117, Oct. 1982.
`Axial transformation of the profunda femoris vein, Seshadri
`Raju, MD; Todd Fountain, BS; Peter Neglen, MD; M.
`Devidas, PhD, Journal of Vascular Surgery, Apr. 1998, vol.
`27, No. 4.
`Duplex Sonographic Evaluation of the Sapheno—femoral
`Venous Junction in Patients With Recurrent Varicose Veins
`after Surgical Treatment, Joseph Elias Benabou, MD, LasZlo
`J. Molnar, MD, Giovanni G. Cerri, PhD, Journal of Clinical
`Ultrasound; vol. 26, No. 8, Oct. 1988.
`Early experimental experience With a surgically created,
`totally autogenous venous valve; Apreliminary report; Mark
`S. Rosenbloom, M.D., James J. Schuler, M.D., Rashad A.
`Bishara, M.D., Salve G. Ronan, M.D., and D. Preston
`Flanigan, M.D., Journal of Vascular Surgery, vol. 7, No. 5,
`May 1988.
`Femoral vein valvuloplasty; Intraoperative angioscopic
`evaluation and hemodynamics improvement; Harold J.
`Welch, MD, Robert L. McLaughlin, RVT, and Thomas F.
`O’Donnell, Jr., MD, Journal of Vascular Surgery, vol. 16,
`No. 5, Nov. 1992.
`In situ venous valve construction, N.M. Wilson, D.L. Rutt;
`N.L. BroWse, Br J. Surg. 1991, vol. 78, May, 595—600.
`Late results after venous valve repair, I Eriksson, B.
`Almgren, L. Nordgren, Inter Angio., 4, 1985.
`Surgical treatment of post—phlebitic syndrome, S.A. Taheri,
`L. LaZar and SM. Elias, Br J. Surg. vol. 69 (Suppl.) (1982)
`S59—S62.
`Neuromyopathy in Venous Insuf?ciency, Syde A. Taheri,
`M.D., F.I.C.A., Angiology—The Journal of Vascular Dis
`eases, Feb. 1988.
`Vein Valve Transplantation, Syde A. Taheri, MD, David R.
`Pendergast, EdD, Ellot LaZar, MD, Larry H. Pollack, MD,
`Michael A. Meenaghan, DDS, PhD., Ronert M. Shores,
`AAS, Thomas Budd, PhD, Paul Taheri, BS, The American
`Journal ofSurgery, vol. 150, Aug. 1985.
`Technical Options in Venous Valve Reconstruction, Seshadri
`Raju, MD, James D. Hardy, MD., TheAmerican Journal of
`Surgery, vol. 173, Apr. 1997.
`Vein valve transplant, Syde A. Taqheri, M.D., F.A.C.S.,
`Louis LaZar, M.D., Steven M. Elias, M.D., Paul Marchard,
`M.D., Surgery, vol. 91, No. 1, Jan. 1982.
`Vein valve transplant. Indiction and results, Syde A. Taheri,
`M.D., Reid Heffner, M.D., Michael A. Meenaghan, D.D.S.,
`Thomas Budd, PhD., Larry H. Pollack, M.D., Int. Angio., 4,
`1985.
`Experimental prosthetic vein valve, Syde A. Taheri, MD,
`David Rigan, MD, Robert MentZer, MD, Robert M. Shores,
`American Journal of Surgery, vol. 156, Aug. 1988.
`
`* cited by examiner
`
`NORRED EXHIBIT 2222 - Page 2
`
`

`

`U.S. Patent
`US. Patent
`
`0a. 9, 2001
`Oct. 9, 2001
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`Oct. 9, 2001
`
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`US 6,299,637 B1
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`NORRED EXHIBIT 2222 - Page 5
`NORRED EXHIBIT 2222 - Page 5
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`

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`U.S. Patent
`
`0a. 9, 2001
`
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`NORRED EXHIBIT 2222 - Page 6
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`

`

`US 6,299,637 B1
`
`1
`TRANSLUMINALLY IMPLANTABLE
`VENOUS VALVE
`
`BACKGROUND OF THE INVENTION
`
`Field of the Invention
`This invention relates to the replacement of incompetent
`venous valves, and, more particularly, to minimally invasive
`methods and devices for transluminally implanting pros
`thetic venous valves.
`The human venous system of the loWer limbs includes the
`super?cial venous system and the deep venous system With
`perforating veins connecting the tWo systems. The super?
`cial system includes the great saphenous vein and the small
`saphenous vein. The deep venous system includes the ante
`rior and posterior tribial veins Which unite to form the
`popliteal vein Which in turn becomes the femoral vein When
`joined by the small saphenous vein. The venous systems
`contain a plurality of valves for directing blood ?oW
`(generally superiorly) to the heart.
`Venous valves are usually bicuspid valves, With each cusp
`forming a sack or reservoir for blood Which, under pressure,
`forces the free edges of the cusps together to prevent
`retrograde How of the blood and alloW only antegrade How
`to the heart. When an incompetent valve attempts to close in
`response to a pressure gradient across the valve, the cusps do
`not seal properly and retrograde How of blood occurs.
`There are tWo chronic venous diseases in Which incom
`petence of venous valves is thought to be an important factor
`in the pathophysiology. These are chronic venous insuf?
`ciency and varicose veins.
`Chronic venous insuf?ciency is essentially caused by
`venous hypertension and chronic venous stasis due to val
`vular incompetence both of a primitive nature (or primary or
`essential or idiopathic) and of a secondary nature folloWing
`past illnesses of the venous system (generally speaking,
`deep venous thrombosis or phlebitis).
`As the veins dilate due to increased pressure, the valves
`in the veins become less able to Withstand the Weight of the
`blood above them. This causes the veins to dilate further and
`the valves in the veins to fail. As they fail, the effective
`height of the column of blood above the feet and ankles
`groWs taller, With an increase in the pressure exerted on the
`tissues of the ankle and foot. When the Weight of that
`column reaches a critical point because of enough dilation
`and valve failures, the patient begins to have ulceration of
`the ankle Which start deep and eventually come to the
`surface. These ulcerations are very dif?cult to heal because
`the Weight of blood causing them still exists, With the
`tendency to enlarge the ulcer, and because they are deep,
`often to the bone. Chronic venous insuf?ciency thus consists
`of hypertension of the loWer limb in the deep, perforating
`and often super?cial veins With associated pigmentation,
`pain, sWelling and ulceration.
`Existing treatments for chronic venous insuf?ciency are
`less than ideal. The only therapies currently available
`include elevation of the legs for tWenty minutes every tWo
`hours, elastic support hose to compress the veins externally
`and surgical repair or replacement of the valves by grafting
`veins from the patient’s arm into the leg. These methods are
`variably effective. Moreover, surgery has associated com
`plications With morbidity and mortality risk and is usually
`very expensive. Similarly, the palliative therapies require
`major lifestyle changes for the patient With potentially
`suboptimal long term patient compliance. Also, Without
`repairing the valves, even if the ulcers are healed, the ulcers
`
`2
`Will recur unless the patient continues to elevate the legs and
`to use support hose continuously.
`The varicose vein condition consists of dilatation and
`tortuosity of the super?cial veins of the loWer limb and
`resulting cosmetic impairment, pain and ulceration. Primary
`varicose veins are the result of primary incompetence of the
`venous valves of the super?cial venous system. Secondary
`varicose veins occur as the result of deep venous hyperten
`sion Which has damaged the valves of the perforating veins,
`as Well as the deep venous valves.
`The initial defect in primary varicose veins often involves
`localiZed incompetence of a venous valve thus alloWing
`re?ux of blood from the deep venous system to the super
`?cial venous system. This incompetence is traditionally
`thought to arise at the saphenofemoral junction but may also
`start at the perforators. Thus, gross saphenofemoral valvular
`dysfunction may be present in even mild varicose veins With
`competent distal veins. Even in the presence of incompetent
`perforation, occlusion of the saphenofemoral junction usu
`ally normaliZes venous pressure.
`The initial defect in secondary varicose veins is often
`incompetence of a venous valve secondary to hypertension
`in the deep venous system. Since this increased pressure is
`manifested in the deep and perforating veins, correction of
`one site of incompetence could clearly be insuf?cient as
`other sites of incompetence Will be prone to develop.
`HoWever, repair of the deep vein valves Would correct the
`deep venous hypertension and could potentially correct the
`secondary valve failure. Apart from the initial defect, the
`pathophysiology is similar to that of varicose veins.
`Effective treatment of venous valvular incompetence
`remains elusive. Some methods of valvular reconstructive
`surgery may alloW the recovery of valvular function in
`certain cases. HoWever, the use of reconstructive surgery is
`limited by the delicate nature, and, in many cases, the
`irreversible damage of the valvular structure.
`While bioprosthetic heart valves are knoWn, bioprosthetic
`venous valves are not readily available. The major deterrent
`in constructing venous valves is the need to provide a valve
`Which remains normally open, but closes under slight back
`?oW. Another deterrent in constructing such valves is the
`need to provide proper valve lea?et and sinus geometry as
`the valve opens and closes. Prosthetic heart valves, and the
`current methods of preparing them, are generally not suit
`able as venous valve replacements. Prosthetic heart valves
`are usually made from porcine valves, Which have a geom
`etry unsuitable as a replacement for venous valves. These
`types of valves are also generally larger than venous valves,
`and include valve lea?ets generally thicker and stiffer than
`the lea?ets of venous valves. The thicker heart valve lea?ets
`require a greater opening pressure, Which can enhance the
`likelihood of venous stasis and thrombus formation, and
`makes such valves unsuitable for the venous system.
`Thus, there remains a need for an implantable valve and
`related support structure and deployment system for replac
`ing incompetent venous valves. Preferably the prosthetic
`valve is transluminally implantable, minimally
`thrombogenic, and meets the How requirements unique to
`the venous system.
`
`15
`
`25
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`35
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`45
`
`55
`
`SUMMARY OF THE INVENTION
`There is provided in accordance With one aspect of the
`present invention, a method of implanting a prosthetic
`vascular valve. The method comprises the steps of providing
`a prosthetic vascular valve having at least one lea?et therein.
`The lea?et has a minor axis extending substantially perpen
`
`65
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`NORRED EXHIBIT 2222 - Page 7
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`US 6,299,637 B1
`
`3
`dicular to a longitudinal axis of the vessel, and a major axis
`extending perpendicular to the minor axis. The lea?et is
`compressed along its minor axis, to a reduced cross sectional
`pro?le and positioned Within the vessel. The lea?et is
`thereafter permitted to self expand along its minor axis,
`Within the vessel. Preferably, the lea?et is pivotably attached
`to a self expandable tubular support structure, for retaining
`the lea?et in a pivotable orientation Within the vessel.
`In accordance With another aspect of the present
`invention, there is provided a self expandable prosthetic
`venous valve. The valve comprises a tubular Wire support,
`expandable from a ?rst, reduced diameter to second,
`enlarged diameter. The tubular Wire support has a ?oW path
`extending therethrough, for permitting venous blood ?oW.
`At least on lea?et is pivotably positioned in the ?oW path,
`for permitting ?oW in a forWard direction and resisting ?oW
`in a reverse direction. The lea?et comprises a major axis
`Which is perpendicular to and longer than a minor axis, and
`the lea?et is compressible and expandable along its minor
`axis betWeen a ?rst, reduced dimension and second,
`enlarged dimension.
`Preferably, the lea?et comprises a Wire frame in Which at
`least tWo longitudinal struts extend generally along the
`direction of the major axis and are connected by a bend. The
`lea?et preferably comprises at least three or four struts
`extending generally along the direction of the major axis.
`The Wire frame of the lea?et is provided With at least one
`and preferably tWo or more pivots Which de?ne an axis of
`rotation. Each pivot is connected to the tubular Wire support,
`to permit the lea?et to pivot With minimal resistance
`betWeen an open and closed orientation. The Wire frame of
`the lea?et preferably further comprises a cover such as a
`PTFE or Dacron envelope or layer. The cover may be tied to
`the frame such as by 6.0 Polypropylene (ProleneTM) suture.
`In accordance With a further aspect of the present
`invention, there is provided an implantable vascular valve.
`The vascular valve comprises a tubular Wire frame, having
`a proximal end, a distal end, and a ?oW path extending
`therethrough. At least one valve lea?et is moveably posi
`tioned Within the ?oW path, and rotatable about an axis
`Which is approximately perpendicular to the ?oW path. The
`lea?et is moveable betWeen a closed position Which is
`inclined Within the range of from about 15° to about 75°
`from the axis of the ?oW path, and an open position Which
`is closer to parallel With the axis of the ?oW path than the
`closed position.
`Preferably, the lea?et comprises a major axis and a minor
`axis, and is compressible along its minor axis to a reduced,
`implantation cross section and self expandable along its
`minor axis to an enlarged, implanted cross section.
`Further features and advantages of the present invention
`Will become apparent to those of skill in the art in vieW of
`the detailed description of preferred embodiments Which
`folloWs, When considered together With the attached draW
`ings and claims.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a schematic side elevational cross-section of a
`segment of a vein, illustrating a prosthetic venous valve
`bypassing an incompetent native valve.
`FIG. 2 is an enlargement of the prosthetic valve of FIG.
`1, shoWn in a closed orientation.
`FIG. 3 is an enlargement as in FIG. 2, With the valve in
`an open orientation.
`FIG. 4 is a schematic layout of a Wire frame for supporting
`the prosthetic valve shoWn in FIG. 1.
`
`15
`
`25
`
`35
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`45
`
`55
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`65
`
`4
`FIG. 4a is a schematic cross-sectional vieW through a
`tubular valve support of the type illustrated in FIG. 1
`shoWing the axis of rotation for the valve lea?et in relation
`to the longitudinal axis of the tubular support.
`FIG. 4b is a schematic cross-sectional vieW as in FIG. 4a
`shoWing the axis of rotation of an alternate valve embodi
`ment such as the tWo lea?et embodiment of FIGS. 7 and 8.
`FIG. 5 is a schematic plan vieW of a laterally compressible
`lea?et in accordance With the present invention.
`FIG. 5a is a schematic plan vieW as in FIG. 5, With eyes
`or loops at each bend.
`FIG. 6 is a perspective vieW of a tWo lea?et “duck bill”
`valve embodiment in accordance With the present invention.
`FIG. 7 is a side elevational schematic vieW of an alternate
`dual lea?et embodiment in accordance With the present
`invention.
`FIG. 8 is a side elevational vieW as in FIG. 7, With the
`valve in the closed orientation.
`FIG. 9 is a schematic plan vieW of the lea?et as seen along
`the lines 9—9 in FIG. 7.
`FIG. 10 is a cross-sectional vieW taken along the lines
`10—10 in FIG. 7.
`FIG. 11 is a side elevational cross-section of a deployment
`catheter in accordance With one aspect of the present inven
`tion.
`FIG. 12 is an enlarged cross-sectional vieW of an alternate
`distal end con?guration for a deployment catheter in accor
`dance With the present invention.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`Referring to FIG. 1, there is illustrated a side elevational
`schematic vieW of a portion of a vein, including a plurality
`of venous valves. Although the present invention Will be
`discussed primarily in the context of treating a patient With
`one or more incompetent venous valves, such as in the deep
`veins of the leg, the valve and valve support of the present
`invention may be utiliZed elseWhere in the body as Will be
`appreciated by those of skill in the art in vieW of the
`disclosure herein.
`Referring to FIG. 1, the vessel 10 such as a vein has an
`anatomically distal (inferior) portion 12, and an anatomi
`cally proximal (superior) portion 14. Normal venous blood
`?oW 16 is from the distal 12 to the proximal 14 direction
`toWards the heart.
`The vessel 10 comprises a Wall 18 and a plurality of
`naturally occurring valves 20. Valves 20 assist in permitting
`blood ?oW 16 in the direction of the heart and resisting
`reverse ?oW as is understood in the art. Each native valve 20
`comprises a ?rst lea?et 22 having a ?rst edge 24 and a
`second lea?et 26 having a second edge 28. Lea?et edges 24
`and 28 are coaptive in a normally functioning valve, to
`permit forWard and inhibit reverse blood ?oW.
`Due to any of a variety of underlying etiology, as dis
`cussed in part in the background of the invention, one or
`more valves 30 may become incompetent. As used herein,
`an incompetent valve is a valve Which fails to adequately
`resist reverse blood ?oW. In the illustrated embodiment,
`incompetent valve 30 is associated With a portion of the
`vessel Wall 32 Which has become diseased or otherWise
`Weakened so that the opposing lea?ets of incompetent valve
`30 are no longer able to coaptively close and inhibit retro
`grade blood ?oW.
`A self expandable prosthetic venous valve graft 40 is
`illustrated spanning the diseased or Weakened Wall section
`
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`US 6,299,637 B1
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`5
`32. Venous valve graft 40 includes one or more valve lea?ets
`42 pivotably or moveably supported Within a frame 44. As
`used herein, “lea?et” refers to a component of the valve
`Which is moveable betWeen a ?rst position in Which blood
`is permitted to ?oW in a forWard direction, and a second
`position Which inhibits blood ?oW in a reverse direction.
`Frame 44 in the illustrated embodiment is provided With a
`tubular cover 46 such as a ?exible, thin Walled PTFE or
`Dacron sleeve.
`The length and diameter of the overall venous valve graft
`40 can be varied Widely, depending upon the intended
`clinical application. In the context of a venous valve support
`intended to span an incompetent venous valve 30 in the deep
`veins of the leg in an adult, venous valve graft 40 Will
`typically have an axial length Within the range of from about
`2 to about 20 centimeters, and often betWeen about 6 and 14
`centimeters. In one embodiment, the venous valve graft 40
`has an axial length of about 10 centimeters. In general, the
`length of the venous valve graft 40 is preferably suf?cient to
`fully span the axial length of the diseased or Weakened Wall
`section 32, and overlap With proximally and distally adja
`cent healthy tissue by a suf?cient distance (e.g., 1—4 cm) to
`?rmly position the venous valve graft 40 in the vein With
`minimal or no risk of migration. Thus, venous valve graft 40
`may be constructed having differing lengths depending upon
`the siZe of the diseased or Weakened Wall portion 32 or other
`treatment site, such as a treatment site Which spans tWo or
`three or more venous valves 20 Which have become diseased
`and are desirably spanned.
`In the case of a patient having multiple incompetent
`venous valves 30, a single relatively long venous valve graft
`40 can be provided having one or more prosthetic valves
`positioned therein to span tWo or three or more native
`valves. Alternatively, as a matter of clinical judgment, a
`physician may prefer to install tWo or three or more discrete
`venous valve grafts 40 positioned axially apart along the
`length of the vein.
`In general, the venous valve graft 40 of the present
`invention is collapsible into a ?rst, reduced cross-sectional
`con?guration such as for transluminal implantation into the
`treatment site, and subsequently radially enlargeable to a
`second, larger diameter for retention and functioning Within
`the vein. In the preferred embodiment, the venous valve
`graft 40 is biased into the second, larger diameter. In this
`manner, implantation of the valve graft 40 can be accom
`plished by restraining the valve graft in the ?rst, reduced
`cross sectional con?guration as Will be discussed and
`implanting the valve graft 40 by releasing it from the
`retention catheter. The valve graft 40 Will thereafter radially
`expand Within the treatment site to the extent necessary to ?t
`the vessel. Aradially outWardly biased valve graft 40 further
`assists in responding to compression pressures Which may
`be experienced as a result of external compression on the
`leg, bending of the knee or other anatomical movement
`Which places a momentary compressive force on the valve
`graft 40.
`The expanded diameter of the venous valve graft 40 can
`be varied depending upon the intended use, as Will be
`apparent to those of skill in the art. The second enlarged
`diameter for a typical deep vein in the leg is on the order of
`from about 8 mm to about 14 mm, although other dimen
`sions may be utiliZed as may be desired. Preferably, a venous
`valve graft 40 Will be selected for a particular vein, having
`a greater unconstrained expanded diameter than the inside
`diameter of the adjacent healthy portions of the vessel 10. In
`this manner, the proximal and distal end attachment Zones on
`the valve graft 40 Will exert a radially outWardly directed
`force on the vessel Wall to assist in retention of the valve
`graft 40.
`
`10
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`15
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`20
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`25
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`30
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`35
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`40
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`45
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`50
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`55
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`60
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`65
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`6
`Preferably, tWo or more radiopaque markers 41 are pro
`vided for enabling visualiZation of the graft during
`deployment, as Well as to enable post deployment evaluation
`of the position of the graft. Preferably, one or tWo or more
`radiopaque markers are provided on the proximal end of the
`graft and one or more markers are provided on the distal end
`of the graft. In addition, at least one and preferably tWo
`radiopaque markers are provided on the valve lea?et. This
`Will enable evaluation of the operation of the lea?et folloW
`ing implantation. The radiopaque markers may comprise
`gold, platinum, or other materials Which are knoWn in the
`art.
`Referring to FIG. 2, there is illustrated an enlarged
`fractional vieW of the valve of FIG. 1, With the valve lea?et
`42 illustrated in a closed orientation. In the illustrated
`embodiment, the valve lea?et pivots about a rotational axis
`48, Which is displaced laterally from the longitudinal axis 64
`of the vessel and of the venous valve graft 40 by an offset
`distance 66 as illustrated in FIG. 4a. Offset distance 66
`cooperates With the generally elliptical pro?le and closure
`angle of the lea?et 42, discussed beloW, to alloW blood ?oW
`in the reverse direction to pivot the lea?et 42 into a closed
`orientation as seen in FIG. 2. Alternatively, blood ?oW in a
`forWard direction 16 (FIG. 3) creates a greater net forWard
`force moment on the lea?et 42 on the lea?et side of the
`rotational axis 48 so that the lea?et 42 opens to permit
`forWard ?oW. In this manner, the valve can pivot betWeen an
`open and closed orientation under very loW ?uid force,
`Which is an important characteristic in the context of venous
`valves.
`The outer tubular cover 46 may be provided With radial
`support throughout its axial length, or, as in the illustrated
`embodiment, periodic radial support. Referring to FIG. 4,
`there is illustrated a Wire layout Which may be utiliZed to
`construct the Wire frame 44 of the venous valve graft 40
`illustrated in FIG. 1. Any of a Wide variety of Wire con?gu
`rations can be utiliZed in the context of the present invention,
`as Will be appreciated by those of skill in the art in vieW of
`the disclosure herein. For example, self-expandable Wire
`structures useful for creating self expandable Wire frames
`capable of supporting one or more valve lea?ets 42 are
`disclosed in Us. Pat. No. 5,800,508 issued Sep. 1, 1998 to
`Goicoechea et al., entitled Bifurcated Endoluminal Prosthe
`sis; U.S. Pat. No. 5,665,115 issued Sep. 9, 1997 to Cragg
`entitled Intraluminal Stent; and Us. Pat. No. 5,507,767
`issued Apr. 16, 1996 to Maeda et al. entitled Spiral Stent, the
`disclosures of Which are incorporated in their entireties
`herein by reference.
`Wire frame 44 comprises at least a ?rst ZigZag section of
`Wire 50, and may additionally comprise a second ZigZag
`section of Wire 52 and a third or more ZigZag section of Wire
`54. Each ZigZag section of Wire 50 comprises at least tWo
`and preferably from about 4 to about 10 substantially
`straight segments 51, 53, joined together by, for example, a
`proximal bend 55. Segment 53 is connected to a segment 57
`by a distal bend 59. Each ZigZag section of Wire 50 prefer
`ably comprises at least about 3 or 4 and as many as 6 or 7
`or 8 or more proximal bends 55 and corresponding distal
`bends 59.
`Each of the sections 50 and 52 are connected by at least
`one connector 56, and each of the sections 52 and 54 are
`connected by at least one connector 58. In the illustrated
`embodiment, the overall Wire layout is constructed from a
`single length of Wire. Each of the ZigZag sections 50, 52 and
`54 may be formed on a cylindrical mandrel, or formed ?at
`and rolled about a longitudinal axis and secured such as by
`soldering or suture into a tubular con?guration Which is
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`US 6,299,637 B1
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`7
`utilized to support the cover 46. This construction conve
`niently allows radial compression such as for loading Within
`a loW pro?le deployment catheter and self-expansion Within
`the treatment site as Will be understood by those of skill in
`the art.
`Where relatively greater radial strength is desired, tWo or
`more adjacent ZigZag sections 50, 52 can be placed imme
`diately adjacent each other With one or more apexes (e.g.,
`55, 59) of opposing ZigZag sections connected as is
`illustrated, for example, in FIGS. 4A through 4F and asso
`ciated disclosure in US. Pat. No. 5,800,508, and FIGS. 2
`through 4 in US. Pat. No. 5,665,115 the disclosures of
`Which have been incorporated herein. Wire or suture loops
`may be used to connect opposing bends on adjacent sections
`of a multi-section graft. Alternatively, single section grafts
`may be used Where an overall length for the valve graft is
`less than about 4 cm and particularly less than about 2 cm
`or 3 cm.
`The Wire frame 44 is preferably provided With tWo or
`more hinge loops 60 and 62 for pivotably supporting one or
`more valve lea?ets 42. In the illustrated embodiment, hinge
`loops 60 and 62 are aligned on and provide a rotational axis
`48 for a single lea?et valve as illustrated in FIGS. 1—3. The
`rotational axis 48 is located With an offset distance 66 from
`the longitudinal axis 64 as is illustrated