United States Patent
`
`[19]
`
`[11] Patent Number:
`
`6,117,167
`
`Goicoechea et al.
`
`[45] Date of Patent:
`
`Sep. 12, 2000
`
`US006117167A
`
`[54] ENDOLUMINAL PROSTHESIS AND SYSTEM
`FOR JOINING
`
`[75]
`
`Inventors: George Goicoechea, Freeport,
`Bahamas; John Hudson, Glenfield,
`United Kingdom; Claude Mialhe,
`Draguignan, France; Andrew H.
`Cragg, Edina, Minn.; Michael D.
`Dake, Stanford, Calif.
`
`[73] Assignee: Boston Scientific Technology, Inc.,
`Maple Grove, Minn.
`
`[21] Appl. No.: 09/020,749
`
`[22]
`
`Filed:
`
`Feb. 9, 1998
`
`Related U.S. Application Data
`
`[63] Continuation of application No. 08/461,513, Jun. 5, 1995,
`Pat. No. 5,716,365, and a division of application No. 08/317,
`763, Oct. 4, 1994, Pat. No. 5,609,627, which is a continu-
`ation—in—part of application No. 08/312,881, Sep. 27, 1994.
`
`[30]
`
`Foreign Application Priority Data
`
`Feb. 9, 1994
`Jun. 10, 1994
`
`[EP]
`[EP]
`
`European Pat. Off.
`European Pat. Off.
`
`............ .. 94400284
`............ .. 94401306
`
`Int. Cl.7 ...................................................... .. A61F 2/00
`[51]
`. . . . . . . .. 623/1.16
`[52] U.S. Cl.
`. . . . . . . . . . . . . . . . . .
`
`[58] Field of Search .................................. .. 623/1, 11, 12,
`623/1.16
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4/1972 Ersek ...................................... .. 623/11
`3,657,744
`3/1975 Alfidi et al.
`.
`3,868,956
`4/1975 Sauvage.
`3,878,565
`6/1975 Wilson .
`3,890,977
`3,996,938 12/1976 Clark, 111.
`4,140,126
`2/1979 Choudhury.
`4,149,911
`4/1979 Clabburn.
`4,214,587
`7/1980 Sakura, Jr..
`4,306,318 12/1981 Mano et al.
`4,425,908
`1/1984 Simon.
`4,503,569
`3/1985 Dotter.
`4,512,338
`4/1985 Balko etal..
`
`.
`
`FOREIGN PATENT DOCUMENTS
`
`0145166B1
`0423916A1
`0 464 755 A1
`0 480 667 A1
`
`6/1985 European Pat. Off.
`4/1991
`European Pat. Off.
`1/1992 European Pat. Off.
`4/1992 European Pat. Off.
`
`.
`.
`.
`.
`
`(List continued on next page.)
`OTHER PUBLICATIONS
`
`Dotter et al., “Transluminal Expandable Nitinol Coil Stent
`Grafting: Preliminary Report”, Technical Developments and
`Instrumentation, Radiology, vol. 147, pp. 259-260 (Apr.
`1983).
`Schetky, “Shape Memory Alloys”, pp. 74-82.
`K. Otsuka et al., “Shape-Memory Alloys-Pseudoelasticity”,
`Metals Forum, vol. 4, No. 3, pp. 142-152 (1981).
`Cragg et al., “Nonsurgical Placement of Arterial Endopros-
`theses: A New Technique Using Nitinol Wire”, Radiology,
`vol. 147, No. 1, pp. 261-263 (Apr. 1983).
`Cragg et al., “Percutaneous Arterial Grafting”, Radiology,
`vol. 150, No. 1, pp. 45-49 (1984).
`T. W. Duerig et al. “An Engineer’s Perspective Pseudoelas-
`ticity”, pp. 369-393.
`Cragg et al., “Stends/Vascular Stents”, Interventional Radi-
`ology, pp. 686-692 (1990.
`
`Primary Exami/1er—Michael J. Milano
`Attorney, Agent, or Firm—Ratner & Prestia
`
`[57]
`
`ABSTRACT
`
`A stent joining means is provided for joining a first endolu-
`minal stent
`to a second endoluminal stent
`to define a
`
`continuous lumen through the first and second endoluminal
`stents. The stent joining means includes two transversely
`spaced female portions on the first endoluminal stent. The
`stent joining means also includes a male engaging portion of
`the second endoluminal stent. The male engaging portion is
`configured to be entered into one of the female portions in
`a radially compressed state and thereafter expanded in the
`female portion such that an outer surface of the male
`engaging portion and an inner surface of the female portion
`are interengaged to resist longitudinal movement to prevent
`separation of the first and second endoluminal stents in
`service.
`
`(List continued on next page.)
`
`82 Claims, 23 Drawing Sheets
`
`EX. l020
`
`EN DOLOGIX, INC
`
`001
`
`

`
`6,117,167
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`1/1994 Lazarus .
`5,275,622
`2/1994 Gianturco .
`5,282,824
`3/1994 Inone .
`5,290,305
`3/1994 Boneau.
`5,292,331
`4/1994 Spaulding .
`5,304,200
`5/1994 Fontaine .
`5,314,472
`7/1994 Song ..................................... .. 606/198
`5,330,500
`. 606/198
`8/1994 Summers
`5,342,387
`
`10/1994 Schnepp—Pesch ..
`623/12
`5,354,309
`
`........................ .. 606/195
`11/1994 Barone et al.
`5,360,443
`5,366,504 11/1994 Anderson et al.
`.
`5379683 12/1994 F°“‘a1“° ~
`ggggvgg £33; 31°‘: °‘a1~~
`53899106
`2/1995 T0“;:r‘"
`’
`’
`'
`5397345
`3/1995 Lazarus ‘
`5,405,377
`4/1995 Cragg .
`5,415,664
`5/1995 Pinchuk.
`5,429,144
`.
`5,443,496
`8/1995 Schwartz .
`5,443,498
`8/1995 Fontaine .
`5,456,713
`10/1995 Chuter.
`5,464,449
`11/1995 Ryan et al.
`5,507,767
`4/1996 Maeda .
`5,507,771
`4/1996 Gianturco .
`5,562,724 10/1996 Vorwerk .................................... .. 623/1
`5,562,727 10/1996 Turk et al.
`..
`623/12
`5,562,728 10/1996 Lazarus et a1.
`. 606/194
`5,571,170 11/1996 Palmaz et al.
`. 606/108
`. . . . . . . . ..
`5,575,817 11/1996 Martin ..... . .
`.. 623/1
`5,662,675
`9/1997 Polansky]—Stockert
`.. 623/1
`5,676,697 10/1997 McDonald ................................ .. 623/1
`FOREIGN PATENT DOCUMENTS
`
`
`
`.
`
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`0508473 A2 10/1992 European Pat. Off.
`0 540 290 A2
`5/1993 European Pat. Off.
`0551179A1
`7/1993 European Pat. Off.
`0556850A1
`8/1993 European Pat. Off.
`0579523A1
`1/1994 European Pat. Off.
`0 536 164 B1
`3/1994 European Pat. Off.
`0 481 365 B1
`6/1994 European Pat. Off.
`0 621 015 A1
`10/1994 European Pat. Off.
`0 621 016 A1
`10/1994 European Pat. Off.
`0 622 088 A1
`11/1994 European Pat. Off.
`0 646 365 A1
`4/1995 European Pat. Off.
`0 656 197 A2
`6/1995 European Pat. Off.
`0 657 147 A2
`6/1995 European Pat. Off.
`0 662 307 A1
`7/1995 European Pat. Off.
`2678508
`4/1991
`France .
`2678508A1
`1/1993
`France .
`3 918 736 A1
`12/1990 Germany .
`4303181A1
`8/1994 Germany .
`2106190A 4/1983 United Kingdom .
`WO89/08433
`9/1989 WIPO .
`WO91/07928
`6/1991 WIPO .
`92/00043
`1/1992 WIPO ...................................... .. 623/1
`WO93/13825
`7/1993 WIPO .
`WO94/17754
`8/1994 WIPO .
`WO95/01761
`1/1995 WIPO .
`
`.
`
`’
`
`’
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`11/1985 Maass et a1.
`4,553,545
`4,560,374 12/1985 Hammerslag.
`4,562,596
`1/1986 Kornberg .
`4,577,631
`3/1986 Kreamer .
`4,580,568
`4/1986 Gianturco .
`4517932 10/1935 Kornberg .
`4,649,922
`3/1937 wiktor .
`4,655,771
`4/1987 Wallsten .
`4,665,906
`5/1987 Jervis .
`4,665,918
`5/1987 Garza et al.
`4,681,110
`7/1987 Witkor.
`4,728,328
`3/1988 Hughes .
`4,729,766
`3/1988 Bergentz et al.
`4 732 152
`3/1988 Wallsten et al
`’
`’
`4733565
`3/1988 Palm” ~
`4,739,762
`4/1988 Palmaz .
`4,762,128
`8/1988 Rosenbluth .
`4,768,507
`9/1988 Fischell et al.
`4,772,264
`9/1988 Cragg ~
`4,776,337 10/1988 Pa1II1aZ ~
`4,800,882
`1/1989 Gianturco .
`4,820,298
`4/1989 LeVeen et al.
`4,830,003
`5/1989 Wolff et al.
`.
`4355515
`3/1939 Hmstead .
`4,873,906
`11/1939 Lindemann et a1.
`4,886,062 12/1989 Wiktor .
`4,886,065
`12/1989 Collins, Jr.
`4,913,141
`4/1990 Hfllstead .
`4922905
`5/1990 smoker.
`4969»458 “/1990 WikF°T-
`4,969,890
`11/1990 Sugita et al.
`4,994,071
`2/1991 MacGregor .
`5,019,085
`5/1991 Hillstead .
`5,019,090
`5/1991 Pinchuk .
`5,035,706
`7/1991 Gianturco .
`5,037,427
`8/1991 Harada et al.
`5,041,126
`8/1991 Gianturco .
`5,047,050
`9/1991 Arpesani
`.
`5,057,092 10/1991 Webster, Jr.
`5,064,435
`11/1991 Porter .................................... .. 606/198
`5,067,957
`11/1991 Jervis .
`5,078,726
`1/1992 Kreamer .
`5,078,736
`1/1992 Behl .
`5,085,635
`2/1992 Cragg .
`5,104,399
`4/1992 Lazarus .
`5,104,404
`4/1992 Wolff .
`5,123,917
`6/1992 Lee .
`5,133,732
`7/1992 Wiktor .
`5,135,536
`8/1992 Hillstead .
`5,151,105
`9/1992 Kwan—Gett .
`5,161,547
`11/1992 Tower .
`5,183,085
`2/1993 Timmermans .
`5,192,297
`3/1993 Hull .
`5,201,901
`4/1993 Harada et al.
`5,207,695
`5/1993 Trout .
`5,236,446
`8/1993 Dumon .
`
`.
`
`.
`
`002
`
`002
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 1 of 23
`
`6,117,167
`
`003
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 2 of 23
`
`6,117,167
`
`FIG. 2A
`
`"0M90rj
`
`in
`
`
`
`004
`
`004
`
`

`
`005
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 4 of 23
`
`6,117,167
`
`1.?.3...
`
`mv.mEav.309.atmu.3...
`
`mam
`
`\
`
`W1W1W1W1
`
`006
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 5 of 23
`
`6,117,167
`
`007
`
`007
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 6 of 23
`
`6,117,167
`
`S:
`
`2:
`
`Est
`
`2:
`
`.\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\.~\\\\\\\\.
`HI!“9.O.O4O4O.O.C.O.O.O.O.O.O.O.O.C.O.O.O.0.6I.6060OOOOOOOOOOOOOOOOOOOOOOO00000000000Oct
`
`Ii.Ill‘vooooooooorosooouooooonaouonououonouhon»
`
`
`
`
`\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
`
`008
`
`008
`
`
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 7 of 23
`
`6,117,167
`
`009
`
`009
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 8 of 23
`
`6,117,167
`
`mfifi
`
`ma
`
`\
`<.
`
`"
`
`mm.9...‘
`
`3:mm
`
`o“
`
`mvofi
`
`\
`
`
`
`\...\\\.
`
`IIIIIIIII\
`
`.mo“,//,r,o....00000000000
`000000000000000000
`I\\IVIIII.\\IIVIUII\\\I\IIII\IIIII
`
`010
`
`010
`
`
`
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 9 of 23
`
`6,117,167
`
`011
`
`011
`
`

`
`U.S. Patent
`
`Sep. 12, 2000
`
`Sheet 10 0f 23
`
`6,117,167
`
`3:«E
`
`012
`
`012
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 11 0123
`
`6,117,167
`
`FIG.11
`
`013
`
`013
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 12 of 23
`
`6,117,167
`
`............
`
`>4»414stlbdbfibfi.
`£0“...
`>....\..w>
`
`3......
`_.§.?....§..
`
`014
`
`014
`
`
`
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 13 0f 23
`
`6,117,167
`
`.4II
`
`a
`..p7.. up_
`2.31.;
`.,....v.o.l.I..I
`1............,.~....4
`..W...u..-Jo.
`
`0
`
`K
`
`2«E
`
`urbODD.s\DD~4C4C4\«4dd
`
`015
`
`015
`
`
`
`
`

`
`U.S. Patent
`
`2:1D...CS
`
`6,117,167
`
`.33WX%wt»-«bondM..u§..._._.~§.~
`
`§‘.»..4
`%%o.“..%......%%um.
`
`t“22e_5....mM§.w...__.....
`.6.T...asplH0?;0,_.%o...o.MH".”.......N.
`
`=s‘
`
`mfi
`
`QHK
`
`Pam
`
`p50>
`2.»...
`
`.3.
`.4.‘e
`
`.o.¢..%.,3.....0.».».“..».o.".o£.$9.....§.,
`
`016
`
`016
`
`
`
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 15 0f 23
`
`6,117,167
`
`.a..o.»...¢w3.3.0..
`$§.._.“...,.....§
`
`T
`
`..
`3
`45
`0 ___o
`-09.2. .-A
`‘.90 o
`‘*9...
`D
`:0‘ o
`.02 202016.
`C T
`7
`0
`O
`. '0
`-
`.<‘>._:O
`5?‘
`O
`‘T
`.029::0.‘
`o::o-'~
`‘.9.’
`2520
`29
`
`em.3...2.30.
`
`
`
`
`
` .......&.e...‘.¢.$0.mmficaaodfl.-0.0040404040104".............,.““.............
`
`..§.3......§.”,
`
`017
`
`017
`
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 16 0f 23
`
`6,117,167
`
`3m.30.
`
`mmm
`
`am
`
`El
`
`gall
`
`«Hm.30.
`
`018
`
`018
`
`
`
`

`
`U.S. Patent
`
`Sep. 12, 2000
`
`Sheet 17 0f 23
`
`6,117,167
`
`w.~......u....~..m
`
`me.omw.~.».§
`
`..~..........mE
`
`mm.3...
`
`8..I\\
`
`8
`
`3.
`
`ms
`
`T’
`Q
`
`...§.§...
`
`019
`
`019
`
`
`
`
`
`
`
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 18 0f 23
`
`6,117,167
`
`svm.3...
`
`020
`
`020
`
`
`

`
`U.S. Patent
`
`Sep. 12, 2000
`
`Sheet 19 0f 23
`
`6,117,167
`
`
`
`
`
`l~;..\.\\\\\\\\\\\I
`.3‘ 2
`.- .94
`.9 4
`-AC‘!
`
`:’o:aI
` 5".‘
`
`’o"o‘
`4
`
`021
`
`021
`
`

`
`U.S. Patent
`
`Sep. 12, 2000
`
`Sheet 20 0f 23
`
`6,117,167
`
`...¢;.~~¢~‘‘'..‘.‘.‘.~\~___...
`
`_:.0
`
`_,.‘.‘...‘.‘.
`
`FIG.27
`
`450
`
`
`
`,.__._A
`
`
`
`
`/\\‘
`//
`30%
`
`
`V1I'-
`.
`O
`6.
`>3.‘-
`.o.::
`£020.
`5?
`.\\\\\\ “\".‘ \\\\\\\\\\\\\\\\\\ ".‘~‘:'
`*3‘?
`$20.
`Po’.
`-.6‘:
`30.:
`
`
`
`
`
`
`
`/
`
`
`
`FIG.25
`
`022
`
`022
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 21 of 23
`
`6,117,167
`
`No.
`
`mgms.
`
`mm.m.~.m
`
`023
`
`023
`
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 22 of 23
`
`6,117,167
`
`FIG.30
`
`024
`
`024
`
`

`
`U.S. Patent
`
`Sep. 12,2000
`
`Sheet 23 0f 23
`
`6,117,167
`
`wm
`
`.3
`
`...
`
`mm.8...
`
`¢r”III’l't.a;III)!
`lit.........
`;.r.Ial.oIoI
`I
`III.I
`/.,......
`
`III
`
`I
`II
`
`025
`
`025
`
`
`

`
`6,117,167
`
`1
`ENDOLUMINAL PROSTHESIS AND SYSTEM
`FOR JOINING
`
`This is a Continuation of U.S. patent application Ser. No.
`08/461,513, filed Jun. 5, 1995 (status: allowed), which is a
`Divisional of U.S. patent application Ser. No. 08/317,763,
`filed Oct. 4, 1994 (status:
`issued), which in turn is a
`Continuation-In-Part of U.S. patent application Ser. No.
`08/312,881, filed Sep. 27, 1994 (status: pending).
`This is a continuation-in-part application of the applica-
`tion of common assignment herewith of inventors George
`Goicoechea, Claude Mialhe, John Hudson and Andrew
`Cragg, entitled BIFURCATED ENDOLUMINAL
`PROSTHESIS, filed on Sep. 27, 1994, for which application
`a serial number had not yet been assigned as of the date of
`filing this continuation-in-part application.
`BACKGROUND OF THE INVENTION
`
`The present invention relates to a bifurcated endoluminal
`prosthesis for use in a bifurcated blood vessel such, for
`example, as the infrarenal portion of a mammalian aortic
`artery where it bifurcates to the common iliac arteries. The
`present invention also embraces a stent connecting means
`for connecting a stent (e.g. a stent which forms part of an
`endoluminal prosthesis) to another stent, as well as appara-
`tus and method for introducing prostheses to the vasculature
`and methods of treating angeological diseases.
`A stent is used to provide a prosthetic intraluminal wall
`e.g.
`in the case of a stenosis to provide an unobstructed
`conduit for blood in the area of the stenosis. An endoluminal
`
`prosthesis comprises a stent which carries a prosthetic graft
`layer of fabric and is used e.g.
`to treat an aneurysm by
`removing the pressure on a weakened part of an artery so as
`to reduce the risk of embolism, or of the natural artery wall
`bursting. Typically, a stent or endoluminal prosthesis is
`implanted in a blood vessel at the site of a stenosis or
`aneurysm by so-called “minimally invasive techniques” in
`which the stent
`is compressed radially inwards and is
`delivered by a catheter to the site where it
`is required
`through the patient’s skin or by a “cut down” technique in
`which the blood vessel concerned is exposed by minor
`surgical means. When the stent is positioned at the correct
`location, the catheter is withdrawn and the stent is caused or
`allowed to re-expand to a predetermined diameter in the
`vessel.
`
`U.S. Pat. No. 4,886,062 discloses a vascular stent which
`comprises a length of sinuous or “zig-zag” wire formed into
`a helix; the helix defines a generally cylindrical wall which,
`in use, constitutes a prosthetic intraluminal wall. The sinu-
`ous configuration of the wire permits radial expansion and
`compression of the stent; U.S. Pat. No. 4,886,062 discloses
`that the stent can be delivered percutaneously and expanded
`in situ using a balloon catheter.
`U.S. Pat. No. 4,733,665 discloses an expandable intralu-
`minal graft which is constituted by a tubular member formed
`from a plurality of intersecting elongate members which
`permit radial expansion and compression of the stent.
`EP-A-0556850 discloses an intraluminal stent which is
`
`constituted by a sinuous wire formed into a helix; juxtaposed
`apices of the wire are secured to one another so that each
`hoop of the helix is supported by its neighboring hoops to
`increase the overall strength of the stent and to minimize the
`risk of plaque herniation; in some embodiments the stent of
`EP-A-0556850 further comprises a tubular graft member to
`form an endoluminal prosthesis.
`The prior art stents and prostheses mentioned above are
`generally satisfactory for the treatment of aneurysms,
`
`2
`stenoses and other angeological diseases at sites in continu-
`ous unbifurcated portions of arteries or veins.
`However,
`the prior art stents and prostheses are not
`wholly satisfactory for use where the site of desired appli-
`cation of the stent or prosthesis is juxtaposed or extends
`across a bifurcation in an artery or vein such, for example,
`as the bifurcation in the mammalian aortic artery into the
`common iliac arteries. For example,
`in the case of an
`abdominal aortic aneurysm (“AAA”) in the infrarenal por-
`tion of the aorta which extends into one of the common iliac
`
`arteries, the use of one of the prior art prosthesis referred to
`above across the bifurcation into the one iliac artery will
`result
`in obstruction of the proximal end of the other
`common iliac artery; by-pass surgery is therefore required to
`connect the one iliac artery in juxtaposition with the distal
`end of the prosthesis to the other blocked iliac artery. It will
`be appreciated by a person skilled in the art
`that
`it
`is
`desirable to avoid surgery wherever possible; the require-
`ment for by-pass surgery associated with the use of the prior
`art prosthesis in juxtaposition with a bifurcation in an artery
`therefore constitutes a significant disadvantage.
`SUMMARY OF THE INVENTION
`
`5
`
`10
`
`15
`
`20
`
`Throughout this specification, the term “proximal” shall
`mean “nearest to the heart,” and the term “distal” shall mean
`“furthest from the heart.”
`
`25
`
`According to one aspect of the present invention there is
`provided a stent connecting means for connecting two
`intraluminal stents one to the other to define a continuous
`
`lumen through the two stents, the stent connecting means
`including a first stent including a male engaging portion
`which can be compressed radially inwardly, and a second
`stent
`including a female cooperating portion. The male
`engaging portion may be entered into the female cooperating
`portion in a radially compressed state and thereafter caused
`or allowed to expand in the female cooperating portion; the
`arrangement being such that in service the interengagement
`of the male engaging portion and the female cooperating
`portion serves to resist longitudinal separation of the two
`stents one from the other.
`
`the first stent may include a proximal male
`Typically,
`engaging portion;
`the second stent may include a distal
`female cooperation portion. The male engaging portion may
`be flared radially outwardly towards its extremity, and the
`female cooperating portion may be tapered radially inwardly
`towards its extremity.
`In some embodiments,
`the male
`engaging portion may comprise a frustoconical wall which
`flares outwardly towards its longitudinal extremity;
`the
`female engaging portion may comprise a frustoconical wall
`which tapers radially inwardly towards its longitudinal
`extremity.
`Alternatively, said male engaging and female cooperating
`portions may be substantially untapered; they may be sub-
`stantially cylindrical.
`The male engaging portion of the first stent may be
`resiliently compressible in a radially inwards direction such
`that in the radially compressed state it is capable of self-
`reexpansion to engage in the female cooperating portion.
`Typically, each of said first and second stents may be
`resiliently compressible.
`In use therefore the second stent may be delivered in a
`radially compressed state by using a catheter; when the
`second stent is located at the site of use, the catheter may be
`withdrawn thereby allowing the second stent to re-expand to
`engage the endoluminal surface of the blood vessel.
`The first stent may then be delivered percutaneously or by
`a “cut down” technique to a site distal of the second stent
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`026
`
`026
`
`

`
`6,117,167
`
`3
`such that the male engaging portion of the first stent in the
`radially compressed state is entered into the expanded
`female cooperating portion of the second stent; the catheter
`may then be withdrawn allowing the first stent to re-expand
`such that the male engaging portion engages in the female
`cooperating portion of the second stent.
`In some embodiments of the present invention the second
`stent may have two transversely spaced distal female coop-
`erating portions; the second stent may therefore constitute a
`bifurcated stent for use in juxtaposition with a bifurcation in
`a blood vessel.
`
`Each of the two transversely spaced distal female coop-
`erating portions may be adapted for connection to a first
`male stent which, in use, extends across the bifurcation into
`a respective one of the branched blood vessels.
`In a particular aspect of the present invention there is
`provided a bifurcated intraluminal stent for use in juxtapo-
`sition with an angeological bifurcation;
`the bifurcated
`intraluminal stent comprising a proximal portion adapted to
`be positioned in service in a blood vessel in juxtaposition
`with a bifurcation, a first distal stent portion adapted to
`extend across the bifurcation into one of the branched blood
`
`vessels and a second distal stent portion adapted to allow
`blood to flow from the proximal portion into the other
`branched vessel. The first distal stent portion may be formed
`integrally with the proximal portion.
`In some embodiments the second distal stent portion may
`comprise a female cooperating portion which is adapted to
`engage a male engaging portion of a another stent adapted
`to extend in the other branched blood vessel such that, in
`use, the bifurcated stent can be connected in situ to the other
`stent. The bifurcated intraluminal stent may therefore con-
`stitute a second stent in accordance with the present inven-
`tion comprising a distal female cooperating portion disposed
`intermediate the proximal and distal extremities of the stent;
`the other stent may constitute a first stent in accordance with
`the present invention.
`Typically, the proximal end of said second stent may be
`flared radially outwardly towards its extremity to engage the
`endoluminal surface of the artery thereby to resist longitu-
`dinal movement of the second stent in service.
`
`Each of the first and second stents may comprise a sinuous
`wire formed into a tubular configuration. The sinuous and
`tubular configurations may be imparted to the wire by
`winding it on a mandrel. Typically, each stent may be made
`from a shape memory nitinol (nickel-titanium) wire which
`may be wound on to the mandrel to form the stent in a
`tubular configuration of slightly greater diameter than the
`diameter of the blood vessel in which the stent is intended
`
`to be used. The stent may be annealed at an elevated
`temperature and then allowed to cool in air so that the nitinol
`wire “remembers” the configuration in which it was wound
`on the mandrel.
`
`Said nitinol wire may be type “M” nitinol wire which is
`martensitic at
`temperatures below about 13° C. and is
`austenitic at temperatures above about 25° C.;
`it will be
`appreciated therefore that the type “M” wire will be auste-
`nitic at body temperature of 37° C. Typically, the annealing
`may be conducted at about 500° C. or more for at least about
`60 minutes; after cooling the wire may be immersed in cold
`water to facilitate removal of the wire from the mandrel with
`
`the wire in its maleable martensitic form. Typically, the cold
`water may have temperature of less than about 10° C.; the
`wire may be immersed for about 5 minutes or more. An
`advantage of using nitinol wire to form the stent in accor-
`dance with the present invention is that the nitinol wire is
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`“super elastic” in its austenitic state; the radial outward force
`exerted by the stent on the wall of the blood vessel in use is
`therefore substantially constant irrespective of the diameter
`of the vessel and the expanded stent.
`In some embodiments the wire may have a helical con-
`figuration as disclosed in EP-A-0556850. Alternatively, the
`wire may be of an entirely novel configuration, namely one
`in which the wire forms a plurality of hoops such that the
`plane of the circumference of each hoop is substantially
`perpendicular to the longitudinal axis of the stent. Each hoop
`may comprise a substantially complete turn of the wire
`having a sinuous configuration; optionally, as each hoop is
`completed, the point of winding the wire may be displaced
`longitudinally with respect to the winding axis to form the
`next hoop. When the next hoop is complete, the point of
`winding is moved further longitudinally with respect to the
`winding axis to the form the next succeeding hoop and so on.
`It will appreciated that an advantage of this novel arrange-
`ment is that the planes of the hoops are not skewed with
`respect to the longitudinal axis of the stent; the longitudinal
`ends of the stent are “square” to said longitudinal axis, so
`that when the stent is caused or allowed to expand in situ
`there is substantially no twisting of the stent as it shortens in
`length. It will be appreciated that this represents a significant
`advantage, as in areas of stenosis or aneurysm it is desirable
`to minimize the movement of the stent within the blood
`vessel so as to reduce the potential trauma to the patient. A
`stent of this configuration may be used, apart from the
`bifurcated embodiment otherwise taught herein,
`in any
`application which in stents generally have heretofor been
`used.
`
`the stents of this invention whether of the
`Typically,
`helical or perpendicular variety, also comprise a securing
`means for securing an apex of the sinuous wire in one hoop
`to a juxtaposed apex of a neighboring hoop so that each hoop
`is supported by its neighbors. The securing means may
`comprise a loop element of a suture material, for example,
`to tie the juxtaposed apices together; the loop element may
`also comprise a loop formed of a thermoplastics material
`such, for example, as polypropylene. Alternatively,
`the
`securing means may be a bead formed of a thermoplastic
`material around juxtaposed apices. Also alternatively, the
`securing means may be a loop, ring, or staple formed of wire
`such as nitinol.
`
`The male engaging portion and female cooperating
`portion, of the first and second interengaging stents of this
`invention, may be formed separately from the remainder of
`the respective non-engaging portions of these stents and then
`the engaging and non-engaging portions secured to one
`another by securing means.
`In one embodiment of the present invention, the proximal
`and distal stent portions of the bifurcated stent in accordance
`with the present invention may be formed separately; the
`distal end of the proximal stent portion may be secured to the
`wider proximal end of a first intermediate frustoconical stent
`portion;
`the narrower distal end of the first intermediate
`frustoconical stent portion may be secured to the proximal
`end of the distal stent portion. The female cooperating
`portion of the bifurcated stent may be constituted by a
`second frustoconical stent portion which is secured to the
`distal end of the proximal stent portion in juxtaposition with
`the first frustoconical portion.
`Alternatively the first and second frustoconical portions
`may be omitted; the proximal and distal stent portions may
`be secured directly one to the other.
`The female cooperating portion may be constituted by a
`generally cylindrical stent portion secured to said proximal
`stent portion in transversely spaced relation to the distal
`portion.
`
`027
`
`027
`
`

`
`6,117,167
`
`5
`Each of the first and second stents of the bifurcated form
`
`of the present invention may carry a tubular graft layer
`formed from a biocompatible fabric in juxtaposition with the
`stent;
`the combined stent and graft layer constituting an
`endoluminal prosthesis. Typically the graft layer may be
`disposed externally of the stent;
`it will be appreciated
`however that in some embodiments the graft layer may be
`disposed internally of the stent. In some embodiments the
`graft layer may be secured to the stent by loop elements
`such, for example, as loops of polypropylene. The biocom-
`patible fabric may be a polyester fabric or a polytetrafluo-
`roethylene fabric; typically said fabric may be woven or a
`warp knitted polyester fabric. In some embodiments the
`woven or a warp knitted fabric may be formed in a seam-free
`bifurcated configuration as a sleeve for a bifurcated stent.
`In some embodiments the male engaging portion of the
`first stent and the female cooperating portion of the second
`stent may be left uncovered. Alternatively, the fabric graft
`layer may extend to the proximal extremity on the external
`surface of the male engaging portion, and may be folded
`over the distal extremity of the female engaging portion to
`form an inner sleeve; in use the external fabric of the male
`engaging portion may butt against the folded over portion of
`the fabric internally of the female cooperating portion to
`form a substantially blood tight seal.
`The present invention in one aspect therefore includes a
`bifurcated endoluminal prosthesis comprising a bifurcated
`stent in accordance with the invention and a tubular graft
`layer.
`The first stent having the male engaging portion may also
`have a tubular graft layer. If required the first prosthesis may
`be introduced in a radially compressed state such that the
`male engaging portion of the first prosthesis is engaged in
`the intermediate female cooperating portion of the bifur-
`cated prosthesis; the first prosthesis is then caused to be
`allowed to re-expand in situ such that the male engaging
`portion engages in the female cooperating portion to resist
`longitudinal separation of the two prosthesis in service.
`The bifurcated prosthesis may be adapted for use in the
`infrarenal portion of a mammalian aorta in juxtaposition
`with the bifurcation of the common iliac arteries for the
`
`treatment of abdominal aortic aneurysms. In use the bifur-
`cated endoluminal prosthesis may be introduced into the
`infrarenal portion of the aorta using a catheter such that the
`first distal stent portion extends into one of the branched iliac
`arteries; the catheter may then be withdrawn allowing the
`prosthesis to re-expand in situ.
`It will be appreciated by a person skilled in the art that the
`prostheses may be introduced to the site of use percutane-
`ously or by “cut down” techniques.
`Any of the stents according to this invention may be
`provided on its external surface with circumferentially
`spaced wire barbs or hooks adapted to engage in the endolu-
`minal surface of the host artery to resist longitudinal move-
`ment or slippage of the stent in use. Typically the barbs or
`hooks may be disposed on part of the stent which is provided
`with a fabric graft layer such that in use the points of the
`artery which are engaged by the barbs or hooks are covered
`by the fabric graft. It will be appreciated by a person skilled
`in the art that the trauma to the artery wall caused by the
`hooks or barbs may cause emboli; the provision of the fabric
`graft over the barbs or hooks in use will therefore help to
`prevent
`the introduction of such emboli
`into the blood
`stream.
`
`The male engaging portion for the first stent may be
`provided with circumferentially spaced hooks or barbs on its
`
`6
`external surface to engage the internal surface of said female
`cooperating means,
`thereby to reinforce the connecting
`means against longitudinal separation of the stents one from
`the other in the service.
`
`The present invention therefore provides a connecting
`means for connecting two stents longitudinally one to the
`other. It will be appreciated that this represents a significant
`step forward in the art as it allows the provision of a
`bifurcated endoluminal prosthesis for use in juxtaposition
`e.g. with arterial bifurcations without requiring by-pass
`surgery to connect one of the branched arteries to the other
`branched artery.
`In particular, the invention provides a bifurcated endolu-
`minal prosthesis which can be positioned in an artery in
`juxtaposition with a bifurcation to extend into one of the
`branched arteries; the bifurcated prosthesis can be connected
`to another prosthesis which extends into the other branched
`artery. The prosthesis can be delivered percutaneously or by
`“cut down” methods and connected together in situ thereby
`to provide effective treatment of an angeological disease
`such, for example, as an aneurysm or a stenosis which
`extends across a bifurcation in a blood vessel without the
`
`need for by-pass surgery.
`In another aspect, this invention provides an introducer
`for delivering, into the vasculature at an angeological bifur-
`cation where a blood vessel branches into two branched
`
`vessels, a bifurcated endoluminal stent or prosthesis having
`a proximal portion adapted to be disposed in the blood vessel
`and a distal portion adapted to be disposed at least partially
`in one of the two branched vessels. The introducer com-
`
`prises a tubular outer sheath, a proximal portion pusher
`disposed at least partially within the outer sheath, and a
`distal portion pusher disposed at least partially within the
`proximal portion pusher.
`The present invention further provides an introducer for
`delivering into the vasculature at an angeological bifurcation
`where a blood vessel branches into two branched vessels, an
`endoluminal prosthesis having a proximal stent portion and
`a distal stent portion. The introducer comprises a tubular
`outer sheath, a proximal portion pusher disposed at least
`partially within the outer sheath and having a proximal end
`adapted to contact the proximal stent portion, a distal portion
`pusher disposed at least partially within the proximal portion
`pusher and having a proximal end adapted to contact the
`distal stent portion; and a balloon catheter, having a balloon
`attached thereto, disposed at least partially within the distal
`portion pusher.
`This invention in another aspect provides a method for
`delivering a bifurcated endoluminal stent or prosthesis hav-
`ing a proximal portion and a first distal portion into the
`vasculature at an angeological bifurcation where a blood
`vessel branches into a first branched vessel and a second
`
`branched vessel. The method comprises inserting a first
`introducer containing the stent or prosthesis into the vascu-
`lature to a predetermined delivery location, the first intro-
`ducer comprising an outer sheath, a proximal portion pusher,
`and a distal portion pusher; withdrawing the outer sheath of
`the first introducer while maintaining the proximal portion
`pusher in a fixed position until the proximal portion of the
`stent or prosthesis is deployed from the first introducer into
`the blood vessel; withdrawing the outer sheath and the
`proximal portion pusher while m