United States Patent [19]
`Rhodes
`
`lllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
`US005593417 A
`5,593,417
`[11] Patent Number:
`[45] Date of Patent:
`Jan. 14, 1997
`
`[54]
`
`INTRAVASCULAR STENT WITH SECURE
`MOUNTING MEANS
`
`[76]
`
`Inventor: Valentine J. Rhodes, 608 Winding
`River Rd., Bricktown, N.J. 08723
`
`[21] Appl. No.: 562,727
`
`[22] Filed:
`
`Nov. 27, 1995
`
`Int. Cl.6
`.................................................... A61M 29/00
`[51]
`[52] U.S. CI . .............................. 606/191; 606/198; 623/1;
`623/12
`[58] Field of Search ..................................... 6061198, 191,
`6061194, 195, 108; 62311, 12; 604/96, 104
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4/1972 Ersek.
`3,657,744
`911977 Liebig et a! ..
`4,047,252
`4,503,569
`3/1985 Dotter.
`4,512,338
`411985 Balko eta! ..
`4/1986 Gianturco.
`4,580,568
`4/1987 Wallsten.
`4,655,771
`3/l988 Palmaz.
`4,733,665
`4,740,207
`4/1988 Kreamer.
`4,776,337 10/1988 Palmaz.
`4,795,458
`1/1989 Regan.
`4,830,003
`511989 Wolff eta! ..
`4,856,516
`8/1989 Hillstead .
`2/1991 MacGregor.
`4,994,071
`5,035,706
`711991 Giantureo et a! ..
`5,122,154
`6/1992 Rhodes ........................................ 623/1
`5,167,614 12/1992 Tessmann et a! ..
`
`5,207,695
`5,275,622
`5,306,286
`5,383,892
`5,387,235
`5,397,345
`5,423,885
`
`5/1993 Trout, III.
`l/1994 Lazarus et a! ..
`4/1994 Stack eta! ..
`111995 Cardon et a! ..
`2/1995 Chuter.
`3/1995 Lazarus.
`611995 Williams.
`
`Primary Examiner-Michael Powell Buiz
`Assistant Examiner-Kevin Truong
`Attorney, Agent, or Firm-Caesar, Rivise, Bernstein, Cohen
`& Pokotilow, Ltd.
`
`[57]
`
`ABSTRACT
`
`An endovascular graft for securement within a vessel, duct,
`or lumen of a living being. The graft comprises a tubular
`graft sleeve and a plurality of ring-like stents mounted on the
`outer surface of the sleeve. Anchoring projections are pro(cid:173)
`vided on the outer surface of the stents. The graft sleeve has
`a passageway extending therethrough, which when-the graft
`is located within the vessel, duct, or lumen serves to carry
`body fluid, e.g., blood, through it in a single direction. This
`action produces a force on the tubular sleeve and the plural
`stents mounted thereon. The anchoring projections extend
`outward from the outer surface of the stents and are arranged
`for engagement with the interior of the wall of the vessel,
`duct, or lumen. The anchoring projections are preferentially
`oriented to include portions extending at an acute angle to
`the direction of the fluid flow to tightly engage the interior
`of the wall of the vessel, duct, or lumen under the force
`applied by the fluid flowing through the device.
`
`15 Claims, 3 Drawing Sheets
`
`Medtronic and Medtronic Vascular
`Exhibit 1001 - Page 1
`
`

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`Medtronic and Medtronic Vascular
`Exhibit 1001 - Page 2
`
`

`

`U.S. Patent
`FIG. 4
`
`Jan. 14, 1997
`
`Sheet 2 of 3
`
`5,593,417
`
`24
`
`26 30
`
`12
`
`FIG.5
`
`12
`
`Medtronic and Medtronic Vascular
`Exhibit 1001 - Page 3
`
`

`

`U.S. Patent
`
`Jan. 14, 1997
`
`Sheet 3 of 3
`
`5,593,417
`
`FIG. 6
`
`24
`
`30
`
`FIG. 7
`
`DIRECTION OF
`BLOOD FLOW
`
`72
`
`8 --t
`
`74
`32
`
`30
`
`FIG. 8
`
`74
`
`24
`
`DIRECTION OF
`BLOOD FLOW
`
`Medtronic and Medtronic Vascular
`Exhibit 1001 - Page 4
`
`

`

`5,593,417
`
`1
`INTRAVASCULAR STENT WITH SECURE
`MOUNTING MEANS
`
`BACKGROUND OF THE INVENTION
`
`10
`
`The invention relates generally to medical devices and
`methods of use in vessels, ducts or lumens of living beings,
`and more particularly to expandable grafts and methods of
`use for opening restrictions therein, e.g., revascularizing
`stenotic arteries.
`Percutaneous balloon intraluminal dilation of vascular
`stenoses or blockages through the use of angioplasty balloon
`catheters have proven quite successful. However, such pro(cid:173)
`cedures are nQt without risk or some drawbacks. In particu(cid:173)
`lar, the angioplasty balloon is inflated within the narrowed 15
`vessel in order to shear and disrupt the wall components of
`the vessel to obtain a large lumen. The relative incompress(cid:173)
`ible plaque remains unaltered by this procedure, while the
`more elastic medial and adventitial layers of the body
`passageways stretch around the plaque. This process pro- 20
`duces subintimal dissection, splitting, tearing, and disruption
`of the intact intima and wall layers. If the section forms a
`transverse tear it produces a flap which may lift away from
`the artery and may produce an obstruction to the lumen, and
`therefore make the blockage and stenosis worse. In addition, 25
`if there is a heavy plaque on one side of the artery wall (as
`occurs in 80% of atherosclerotic stenotic lesions) the thinner
`layer may be disrupted by the inflation of the balloon and
`cause hemorrhage. Moreover, after the balloon is decom(cid:173)
`pressed any loose material may dislodge completely and act 30
`as an embolic source to occlude the lumen of the vessel
`distally to such an acute extent as to result in significant
`emergency ischemic conditions. This situation has occurred
`frequently enough to pose a significant risk to the patient.
`Laser assisted balloon angioplasty has been used fre(cid:173)
`quently in recent years to revascularize a totally occluded
`vessel. In particular the occlusion is opened with the laser
`and then the opening is expanded further by balloon angio(cid:173)
`plasty. One of the problems with this revascularization
`procedure is that the laser causes intimal damage along with
`the balloon. Moreover, this procedure has only been useful
`for short segment occlusions. When long segment occlu(cid:173)
`sions are attacked by this procedure the reocclusion rate has
`proven to be very high, and sometimes even made worse.
`In both simple balloon angioplasty and in laser assisted
`balloon angioplasty there is a high incidence of recurrence
`of the stenosis or obstruction. This is, of course, in addition
`to the risk of embolization and acute occlusion and disrup(cid:173)
`tion of the artery with massive hemorrhage. In addition,
`there are certain vessels bearing areas of plaque which are
`not amenable to balloon angioplasty because of the fact that
`they are orificial plaques, i.e., plaques at the orifice of a
`branch artery. Thus, when the balloon is inserted across this
`type of lesion and inflated, it inflates differentially, that is the
`portion of the balloon in the larger part of the artery inflates
`more than the portion of the balloon crossing the narrowed
`or stenotic segment. In fact the portion of the balloon
`crossing the narrowed or stenotic segment frequently does
`not inflate at all. Therefore, unsuccessful attempts at infla(cid:173)
`tion are the rule rather than the exception. This is particularly
`true in attempting the revascularization of renal arteries or
`the superior mesenteric artery.
`Intraluminal endovascular grafting has been demonstrated
`by experimentation to present an alternative to conventional 65
`vascular bypass surgery. Such "grafting" involves either the
`percutaneous insertion into a blood vessel of a tubular
`
`2
`prosthetic graft or stent or an open insertion thereof through
`a short segment exposed portion of the blood vessel. The
`graft is typically positioned in a predetermined location
`within the blood vessel and then expanded by a catheter
`5 delivery system. However, the use of conventional bypass
`grafts exhibits the tendency of recurring stenosis. Such
`restenosis may progress to the point where the graft fails. In
`this connection the cause of stenosis in bypass grafts
`(including dialysis access fistulas) is usually fibro-intimal
`hyperplasia (also known as pseudo-intimal hyperplasia or
`neo-intimal hyperplasia), a very elastic fibrous tissue which
`recoLlapses almost immediately upon relaxation of the
`balloon. Such tissues are, however, ideal for being supported
`by a stent (i.e., a self supporting member).
`Accordingly, it has been suggested, and there is some
`activity now occurring, to use stents in revascularization
`procedures to preclude restenosis. Another useful area of
`stent application is percutaneous angioplasty of Takayasu
`arteritis and neurofibromatosis arterial stenoses, since those
`conditions may show poor response and reoccurrence which
`is very high due to the fibrotic nature of these lesions.
`Examples of various types of expandable grafts/stents are
`disclosed in U.S. Pat. Nos. 3,657,744 (Fursek); 4,047,252
`(Liebig et al.); 4,503,569 (Dotter); 4,512,338 (Balko et al.);
`4,580,568 (Gianturo); 4,655,771 (Wallsten); 4,733,665 (Pal(cid:173)
`maz); 4,740,207 (Kreamer); 4,766,337 (Palmaz); 4,795,458
`(Regan); 4,830,003 (Wolff et al.); 4,856,516 (Hillstead);
`4,994,071 (MacGregor); and 5,035,706 (Giantureo et al.),
`and in the following literature: "Balloon-Expandable Intra-
`coronary Stents in the Adult Dog", Circulation, August
`1987, pages 450-456, Vol 76, No 2; "Normal and Stenotic
`Renal Arteries: Experimental Balloon-expandable Intralu(cid:173)
`minal Stenting", Radiology, 1987, pages 705-708, Vol164,
`No 3; "A Titanium-Nickel Alloy Intravascular Endoprosthe-
`35 sis", Transactions American Society of Artificial Internal
`Organs, 1988, pages 399-403, Vol. XXXIV; "Self-Expand(cid:173)
`ing Endovascular Stent in Experimental Atherosclerosis",
`Radiology, March 1989, pages 773-778, Vol. 170, No. 3;
`"Emergency Stenting for Acute Occlusion After Coronary
`40 Balloon Angioplasty", Circulation, Nov. 1988, pages
`1121-1127, Vol 78, No 5; "Intravascular Stents for Angio(cid:173)
`plasty", CARDIO, December 1987; "Intra-Arterial Stenting
`in the Atherosclerotic Rabbit", Circulation, September 1988,
`pages 646-653, Vol 78, No 3; "Intravascular Stents to
`45 Prevent Occlusion and Restenosis After Transluminal
`Angioplasty", The New England Journal of Medicine,
`March 1987, pages 701-706, Vol. 316, No. 12; "A Polyester
`Intravascular Stent for Maintaining Luminal Patency",
`Texas Heart Institute Journal, Nov. 1, 1988, pages 12-16,
`50 Vol. 15. "Post Dilatation Stenting; Early Experience of the
`Use of an Endocoronary Prosthesis to Prevent Restenosis
`Reoccurrence After Angioplasty", J. Cardiovasc. Surg. 28,
`1987, Session 8: CARDIAC-CORONARY (II); "Intravas(cid:173)
`cular Stents to Prevent Occlusion and Restenosis After
`55 Transluminal Angioplasty", Abstract from New England
`Journal of Medicine 1987, Volume 316, pages 701-706;
`"Vascular Stenting in Normal and Atherosclerotic Rabbits",
`Circulation, February 1990, Vol 81, No. 2, pages 667-683;
`Treatment of Major Venous Obstruction with an Expandable
`60 Endoluminal Spiral Prosthesis, J. Cardiovasc. Surg. 30,
`1989, pages 112-117; and Venous Stenases in Dialysis
`Shunts: Treatment with Self-Expanding Metallic Stents,
`Radiology, February 1989, Vol. 170, No.2, pages 401-405.
`In my U.S. Pat. No. 5,122,154, whose disclosure is
`incorporated by reference herein, there is disclosed an
`intraluminal bypass graft which overcomes many of the
`disadvantages of the prior art devices. That bypass graft is
`
`Medtronic and Medtronic Vascular
`Exhibit 1001 - Page 5
`
`

`

`5,593,417
`
`3
`arranged for placement in a blood vessel, duct, or lumen, to
`hold it open. The graft comprises a sleeve having plural
`stents thereon. The sleeve is an elongated tubular member
`formed of a conventional graft material which is flexible and
`impervious to the ingrowth of tissue therein. Each stent is a 5
`generally ring-like member formed a plurality of intercon(cid:173)
`nected movable links and is mounted about the periphery of
`a surface, e.g., inner or outer, of the sleeve at selected points
`along the sleeve to form respective spaced first sleeve
`sections. Each of the first sections extends for only a portion 10
`of the length of the graft, thereby leaving a plurality of
`second sleeve sections interposed between the first sleeve
`sections. The stents and the sleeve are arranged to be
`expanded, e.g., by a balloon catheter, from a compact state
`to an expanded state to increase the inner cross sectional area 15
`diameter of the sleeve. In the expanded state the stents are
`resistant to contraction back to the compact state. The graft
`is able to bend with respect to its longitudinal axis to enable
`it to be readily accommodated within a curved blood vessel,
`duct, or lumen.
`The graft of my aforementioned patent makes use of some
`anchoring means, e.g., small dome shaped projections, for
`aiding in the securement of the graft in place within the
`vessel, duct, or lumen. While such anchoring means are
`believed effective for their intended purpose, they never the
`less appear to be amenable to improvement insofar as graft
`retention is concerned.
`Various U.S. Pat. Nos. have disclosed devices for intralu(cid:173)
`minar location and securement, which devices include plural
`projections for effecting such securement, such as: 5,167,
`614 (Tessman et al.); 5,207,695 (Trout III); 5,275,622 (Laz(cid:173)
`arus et al ); 5,306,286 (Stack et al ); 5,383,892 (Cardon et
`al.); 5,387,235 (Chuter); 5,397,345 (Lazarus); and 5,423,885
`(Williams).
`Notwithstanding the foregoing, a need exists for means
`for ensuring good retention from migration for intraluminal
`grafts.
`
`4
`The medical device basically comprising a tubular mem(cid:173)
`ber and anchoring means. The tubular member has a pas(cid:173)
`sageway extending therethrough and outer periphery, and is
`arranged to have fluid flow through its passageway in a first
`direction when the device is located within the vessel, duct,
`or lumen, whereupon a force is applied to the tubular
`member. The anchoring means are located adjacent the outer
`periphery of the tubular member and comprise plural pro(cid:173)
`jections.
`The projections are arranged for engagement with the
`interior of the wall of the vessel, duct, or lumen, and are
`preferentially oriented to include portions extending at an
`acute angle to the first direction. These portions tightly
`engage the interior of the wall of the vessel, duct, or lumen
`under the force applied to the tubular member by the fluid
`flowing through the passageway in the first direction. In
`particular, the force applied to the tubular member by the
`fluid flowing through the passageway produces on each of
`the preferentially oriented projections a force component
`20 extending in the first direction (the direction of fluid, e.g.,
`blood, flow), and a force component extending perpendicu(cid:173)
`lar! y (i.e., radial! y) to the first direction, to thereby cause the
`projections to tightly engage, e.g., burrow slightly into, the
`interior of the wall of the vessel, duct, or lumen to thereby
`fixed! y secure the device in place.
`In accordance with the preferred embodiment of the
`invention the device is, endovascular graft, wherein the
`tubular member comprises a graft sleeve having plurality of
`ring-like stents disposed about the outer periphery thereof.
`30 The anchoring means are located on the outer surface of the
`stents. The stents and the graft sleeve are expandable from
`a compact state to an expanded state, whereupon the anchor(cid:173)
`ing means engage the interior of the vessel, duct, or lumen.
`The flow of fluid, e.g., blood, through the device applies the
`force through the graft sleeve and the stents to the anchoring
`projections, to cause the anchoring projections to tightly
`engage, e.g., burrow slightly into, the interior of the vessel,
`duct, or lumen.
`
`25
`
`35
`
`OBillCTSOFTHEINVENTION
`
`40
`
`DESCRIPTION OF THE DRAWINGS
`
`Other objects and many attendant advantages of this
`It is a general object of this invention to provide intralu(cid:173)
`invention will become readily appreciated as the same
`minal medical devices and methods of use of the same which
`becomes better understood by reference to the following
`overcome the disadvantages of the prior art.
`45 detailed description when considered in connection with the
`It is a further object of this invention to provide anchoring
`accompanying drawings wherein:
`means for intraluminal medical devices, e.g., endovascular
`FIG. 1 is a longitudinal view, partially in section, of an
`grafts, stents, etc, arranged to be fixedly secured within a
`artery revascularized by an endovascular bypass graft con(cid:173)
`vessel, duct, or lumen of a living being.
`structed in accordance with the subject invention, with the
`It is a further object of this invention to provide anchoring
`graft being shown in its expanded state;
`means for intraluminal medical devices to be secured within 50
`FIG. 2 is an enlarged isometric view of a portion of the
`in a vessel, duct, or lumen of a living being, and which
`endovascular bypass graft shown in FIG. 1;
`anchoring means is simple in construction.
`It is a further object of this invention to provide anchoring
`FIG. 3 is a more greatly enlarged isometric view of a stent
`means for intraluminal medical devices to be secured within
`portion of the graft shown within the area bounded by the
`in a vessel, duct, or lumen of a living being, and which 55 broken lines bearing the designation 3 in FIG. 2;
`anchoring means does not pose a significant risk of perfo-
`FIG. 4 is a greatly enlarged sectional view taken along
`rating the tissue of the vessel, duct, or lumen.
`line 4-4 of FIG. 1;
`FIG. 5 is a cross-sectional view through the artery of FIG.
`60 1 and showing the graft in its compact state, prior to
`expansion;
`FIG. 6 is an enlarged isometric view similar to FIG. 2 of
`another alternative embodiment of endovascular bypass
`graft constructed in accordance with this invention;
`FIG. 7 is a plan view of a portion of yet another alternative
`embodiment of a graft constructed in accordance with this
`invention; and
`
`These and other objects of this invention are achieved by
`providing an intraluminal medical device for securement
`within a vessel, duct, or lumen of a living being. The vessel,
`duct, or lumen has an interior surface and is arranged to have 65
`a body fluid, e.g., blood, flow therethrough in a first direc(cid:173)
`tion.
`
`SUMMARY OF THE INVENTION
`
`Medtronic and Medtronic Vascular
`Exhibit 1001 - Page 6
`
`

`

`5,593,417
`
`5
`FIG. 8 is an enlarged sectional view taken along line 8-8
`of FIG. 7.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`6
`The pleated tube or sleeve is normally in a compacted state
`as shown in FIG. 5, that is each of the pleats overlies and
`abuts a contiguous portion of an immediately adjacent pleat.
`The sleeve is arranged to be expanded to a maximum
`5 expanded state wherein its pleats open up and form a
`generally continuous curved, e.g., cylindrical, inner and
`outer surface. The inner surface forms the passageway P
`through the graft device through which blood will flow.
`When the graft is in the compacted state of FIG. 5 its
`outside diameter is substantially less than when it is in the
`expanded state. Moreover, when the graft sleeve is in its
`expanded state, its internal cross-sectional area is substan(cid:173)
`tially greater than in the compact state. It must be pointed out
`at this juncture that the graft may be partially expanded in an
`artery to be revascularized, whereupon its pleats do not fully
`open up (flatten out). In such a case the internal cross
`sectional area is less than in the fully expanded state, but
`more than in the compacted state, and thus still permits the
`freer flow of blood therethrough than would flow through
`20 natural passageway in the restriction.
`The spaced stent members 26 serve as the means for
`holding or retaining the sleeve 24 in any desired expanded
`state (i.e., from a slightly partially expanded state, not
`shown, to the fully expanded state like shown in FIG. 1).
`Thus, as can be seen best in FIG. 3, each stent member 26
`basically comprises a plurality of interconnected links 30.
`Each of the links is an elongated rigid member formed of
`stainless steel or some other suitable biocompatible material,
`e.g., tantalum, plastic. Each link has a pair of ends and is
`joined to an associated link via a pivotable joint 32. Each
`joint 32 is made up of one end of one link and the other end
`of the immediately adjacent link. The link ends are con(cid:173)
`nected by any suitable means, e.g., a deformable member, a
`pin, etc., to enable the links to pivot outward with respect to
`each other so that the angle therebetween increases, yet
`which precludes the links from pivoting backward toward
`each other. When so arranged the links form a zig-zag
`pattern. In the embodiment shown herein each joint 32
`comprises the material making up the links themselves, and
`such material is deformable, but not resilient, so that once
`deformed, i.e., the links pivoted outward, it doesn't return to
`its previous configuration.
`As should be appreciated by those skilled in the art when
`the links are pivoted outward with respect to each other the
`stent 26 expands from its compact state to the expanded
`state, like that shown in FIG. 1.
`In accordance with a preferred aspect of this invention the
`joints 42 at the interfaces of each of the links of the stents
`are arranged to maintain any angular orientation between the
`connected links from the compact state to the maximum
`expanded state such that once the stents 26 are expanded to
`any expanded state (whether partial or full) movement back
`to the compact state is precluded.
`The links of the stents of this invention serve to hold the
`sleeve member 24 in its expanded state. To that end, in the
`embodiment shown herein each of the stents is mounted on
`the outside of the sleeve, whereupon the links of those stents
`are connected to one or more pleats 28 externally of the
`60 sleeve, i.e., on the outer surface of the sleeve. If desired, the
`stents 26 could be disposed or mounted within the sleeve. In
`the later case the links can be connected internally of the
`sleeve. Moreover, if desired, the stents may be completely
`encased in the graft material forming the sleeve.
`In the preferred embodiment shown in FIG. 1, each of the
`stents 26 is made up of pairs of interconnected links to form
`two zig-zag patterns sharing common joints, thereby creat-
`
`50
`
`Referring now to various figures of the drawing where
`like reference numerals refer to like parts there is shown at
`20 in FIG. 1 an expandable, intraluminal bypass graft device
`constructed in accordance with this invention. The graft 10
`device 20 is constructed in accordance with the teachings of
`my aforementioned patent, except for the means for fixedly
`holding it in place within the vessel, duct, or lumen. In this
`regard the subject invention makes use of anchoring means,
`to be described later, which offer an improvement in reten- 15
`tion over the "protuberances" disclosed in my aforemen(cid:173)
`tioned patent.
`Before describing the improved anchoring means of this
`invention a brief description of the graft device is in order.
`To that end, the graft device 20 is particularly suited for
`revascularizing lesions, e.g., atherosclerotic plaque lesions,
`in arteries. However, it should be appreciated that the graft
`device as disclosed herein can be used for other intraluminal
`applications, as well. Moreover, the anchoring means of this
`invention can be used in other intraluminal medical devices. 25
`In this regard, the anchoring means can be incorporated into
`any intraluminal device for securement in a vessel, duct, or
`lumen in the body of a living being, and through which a
`body fluid will flow.
`In FIG. 1 the endovascular graft device 20 is shown in a 30
`typical long segment lesion 10 of an artery 12. The lesion is
`made up of atherosclerotic deposits forming a small or
`narrow, restricted passageway for flow of blood there(cid:173)
`through. The endovascular graft 20 is configured so that it is
`initially in a compact or compressed state shown in cross 35
`section in FIG. 5. In that state it is arranged to be readily
`inserted into the arterial passageway, via any conventional
`means, e.g., a balloon catheter 14 shown in phantom in FIG.
`1 and positioned so that it extends through the restriction.
`Once in position the graft 20 is expanded to an expanded 40
`state, like that shown in FIG. 1 by inflating the balloon 14.
`In the maximum expanded state the graft 20 has a central
`passageway P (FIG. 2) which is of maximum internal
`cross-sectional area. When the graft 20 is in the expanded
`state a substantially greater cross-sectional area of the arte- 45
`rial section is open to the free flow of blood therethrough
`than prior to the use of the graft 20.
`As discussed earlier, the expansion of the graft 20 from a
`compacted state shown in FIG. 5 to the expanded state
`shown in FIG. 1 is preferably accomplished by a conven(cid:173)
`tional balloon catheter 14. However, any suitable other
`expansion means or instrument (not shown) may be used.
`Referring now to FIGS. 1, 2 and 5, it can be seen that the
`graft device 20 basically comprises an elongated tubular 55
`member or sleeve 24 having a plurality of expandable,
`ring-like, stent members or sections 26 located at equidis(cid:173)
`tantly spaced positions along the longitudinal length of the
`sleeve member 24. The sleeve member is formed of a thin
`and highly flexible material, such as expanded polytetrafio(cid:173)
`roethylene used for conventional vascular grafts. Examples
`of such prior art graft materials are those sold by W. C. Gore
`and Company under the trademark GORTEX or those sold
`by Impra, Inc. under the trademark IMPRAGRAFT.
`The sleeve 24 is configured so that it is pleated, i.e., it 65
`includes a plurality of longitudinally extending pleats 28.
`Each of the pleats extends the entire length of the graft 20.
`
`Medtronic and Medtronic Vascular
`Exhibit 1001 - Page 7
`
`

`

`5,593,417
`
`10
`
`15
`
`7
`ing a diamond-like pattern stent. In FIG. 6 there is shown an
`alternative graft using plural spaced stents 34. Each stent 34
`comprises a plurality of links 30 which are interconnected
`via joints 32 (like that of the embodiment shown in FIG. 1),
`except the links are not paired, so that a single zig-zag 5
`pattern is produced instead of the diamond-like pattern of
`FIG. 1. In all other regards the graft device utilizing stents
`34 is the same as that described heretofore.
`In order to help hold or secure the graft in position in the
`artery (or lumen or duct) once the graft has been expanded,
`the graft includes the heretofore mentioned anchoring
`means. Such anchoring means comprise plural protuber(cid:173)
`ances or projections 40. In the preferred embodiments
`disclosed herein the protuberances are mounted on the stents
`26 and 34. In particular, each stent includes a plurality of
`protuberances or projections projecting slightly outward
`therefrom and from the outer surface of the graft sleeve. As
`will be described in detail later, these projections 40 are
`preferentially oriented so that the force of the fluid, e.g.,
`blood, flowing through the graft device 20 is applied to them
`to cause them to tightly engage the interior of the wall
`making up the vessel, duct, or lumen. In particular, as will
`be described in detail with respect to FIGS. 3 and 4, the
`projections 40 include portions extending at an acute angle
`to the direction which the fluid flows through the device
`when the device is positioned intraluminally, whereupon the
`force applied to the projections by that fluid flow includes a
`force component extending in the direction of the fluid flow
`and a force component extending radially, i.e., perpendicu(cid:173)
`larly to the direction of the fluid flow. This action causes the
`projections to tightly engage, e.g., burrow slightly into, the
`interior of the vessel, duct, or lumen to fixedly secure the
`device in place.
`Before describing the construction of the projections 40,
`it should be pointed out, that they can be located on any
`exterior portion of the device 20 in order to engage the
`interior of the vessel, duct, or lumen to secure the device in
`place. In the preferred embodiment shown herein the pro(cid:173)
`jections 40 are located on the stents, and in particular, at the
`joints of the stents. This is merely exemplary. Thus, the 40
`projections can be located at any suitable portion on the
`stents, so long as when the stent is expanded the projections
`40 are properly preferentially oriented (as will be described
`later). Moreover, the mechanism, e.g., pivot pin, deformable
`member, etc., forming each joint of the stent may itself form 45
`a projection.
`In the case of an interiorly located stent, i.e., a device
`wherein the stent is located on the interior of the sleeve or
`embedded within the material making up the sleeve (as
`discussed earlier), if the interior stent is to include the
`projections 40 as a part of it, those projections must extend
`through the sleeve so as to be located on the outer surface of
`the sleeve. Another suitable arrangement for an device using
`a interiorly located stent is to utilize projections which are
`not part of the stent itself. In such an alternative arrangement
`the projections may form a separate component of the device
`20, e.g., be separate elements, mounted on the outer surface
`of the sleeve in order to engage the interior of the vessel,
`duct, or lumen.
`Referring now to FIGS. 3 and 4, the details of the
`projections 40 will now be described. As can be seen therein
`each projection is of a generally "arrow head" shape when
`viewed in plan. In particular, each projection includes a
`leading edge 42 defining the "tip" of the "arrow-head." The
`leading edge 42 extends upward at an acute angle to the
`exterior surface of the stent and terminates at the top surface
`44 of the projection. The top surface 44 is generally planar
`
`8
`and inclines upward in the direction of blood flow. That
`direction is designated by the arrow 46 in FIGS. 3 and 4. The
`trailing edges of each projection 40 are designated by the
`reference numbers 48, 50, and 52 (FIG. 3), and each inclines
`upward in the direction of the blood flow to terminate at the
`top surface 44 in respective penetration points 54, 56, and
`58, respectively. Thus, as can be appreciated each of the
`projections 40 includes portions which are preferentially
`oriented at an acute angle to the direction of blood flow. The
`acute angle is shown in FIG. 4 and designated by the
`reference numeral 60.
`As will be appreciated by those skilled in the art, with
`blood (or some other fluid) flowing through the device 20 in
`the direction of arrow 46 a force will be applied by that flow
`to the interior surface of the sleeve 24, and from there
`through the stents to the projections 40. The force applied to
`the projections 40 will have a force component directed in
`the direction of the fluid flow, and a force component
`perpendicularly thereto, i.e., extending radially outward.
`Thus, the flow of fluid, e.g., blood, through the device 20
`20 will tend to force the projections 40 into good engagement
`with the wall 12 of the vessel, duct, or lumen. In the
`embodiment shown herein the projections penetrate or bur(cid:173)
`row slightly into the artery wall, as shown clearly in FIG. 4.
`Such penetration may not be necessary for good resistance
`to migration of the device. If some penetration is deemed
`desirable the height of the projections is selected so that their
`penetrating points do not penetrate too deeply into the artery
`wall. In this regard, the height of the projections is selected
`so that they do not penetrate into the adventicial or medial
`layers of the artery wall, but can penetrate its intima. It is
`anticipated that for applications within the very largest
`arteries, such as the abdominal aorta, that the height of the
`projections will be in the range of approximately 1.0 mm to
`1.5 mm. For intermediate arteries, the height of the projec-
`tions will be in the range of approximately 0.75 mm to 1.0
`mm, and for small arteries, the height of the projections will
`be in the range of approximately 0.5 mm to 1.0 mm.
`As should be appreciated by those skilled in the art the
`number of projections used in any device will also be a
`considerable factor in the amount of securement against
`migration provided thereby. Thus, as a general proposition,
`the more projections utilized the less "penetration" or "bur(cid:173)
`rowing" will necessary for good securement against migra-
`tion.
`In FIGS. 7 and 8, there is shown an alternative construc(cid:173)
`tion of lockin