AU759269B2 - Bifurcated endoluminal prosthesis - Google Patents

Bifurcated endoluminal prosthesis Download PDF

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Publication number
AU759269B2
AU759269B2 AU53401/00A AU5340100A AU759269B2 AU 759269 B2 AU759269 B2 AU 759269B2 AU 53401/00 A AU53401/00 A AU 53401/00A AU 5340100 A AU5340100 A AU 5340100A AU 759269 B2 AU759269 B2 AU 759269B2
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Australia
Prior art keywords
introducer
stent
distal
prosthesis
proximal
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AU53401/00A
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AU5340100A (en
Inventor
Andrew Cragg
Michael Dake
George Goicoechea
John Hudson
Claude Mialhe
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Boston Scientific Scimed Inc
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Boston Scientific Technology Inc
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Priority claimed from AU32245/99A external-priority patent/AU725720B2/en
Application filed by Boston Scientific Technology Inc filed Critical Boston Scientific Technology Inc
Priority to AU53401/00A priority Critical patent/AU759269B2/en
Publication of AU5340100A publication Critical patent/AU5340100A/en
Priority to AU29352/02A priority patent/AU776868B2/en
Priority to AU29353/02A priority patent/AU776872B2/en
Application granted granted Critical
Publication of AU759269B2 publication Critical patent/AU759269B2/en
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Description

P/00/011 28/5/91 Regulation 32(2)
AUSTRALIA
Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: BIFURCATED ENDOLUMINAL PROSTHESIS The following statement is a full description of this invention, including the best method of performing it known to us B 1 RCA."T ED -7NDOL UMI N AL PRO 0S-,thE 7S 7S 3ACKGRMLYD 0:7 TIHE E.'FV'ENTIO The oresenz invention re-aes :o a bifurcarcae Sendou~ma orosc-esis ffor use in a b4 furca -ed blood~vse such, for exarnole, as c'-e inFrarena. oorcion 0: a -amalia'.
aorcic artery wnere it bifurcates co the cot-mron iliac arteries. The Dresen_ -inventi.on also embraces a stent connecting means for coar--!rting a stentz a stent wnic.
forms oart: of an endolu:-,inal prosthesis) to anOther scent, as well as acoaratus and mecnod for introducing prostheses to the vasculature and metnhods of treating angeological diseases.
:A stent' is used to or'ovide a oroschet:ic intraiwn.inal wall e.g. in the case of a stenosis to provide an unobstructed 15 conduit for blood in t~he area of the stenosis. k~n endolurninal orosthesis comorises a scent which ca-rries a prosthnetic graft layer of fabric and is used e.g. to treat an aneurysm by removing the pressure on a weakened Dart, off an artery so as to reduce the risk of e.-,bolism, or of the natural artery wall *20 bursting. Typically, a scent or endoluminal orosthesis is implanted in a blood vessel at the site oL' a scenosis or aneurysm by so-called 'minim~ally invasive technicues" in WhIich the scent is comoressed radially inw.ards and is delivered by a catheter to the site where it is required through the pat ient' s skin or by a c ur do c echnioue inl which the blood v~z-se. c-c:ndis C:=oSza by minor- surgical rieanis. When h stL§2. i.S positioned at the correct locaciot'., the catheter- *s -withdrawn and the stent caused or- allowed to re-exoand to a or-edeterrulined diameter infl the vessel.
U.S. Patent. ,,SS ,062 discloses a vascular scentz ,which comorises a ienath oL sinuous or 'zio- :ag" wire formed I f. 2into a helix; the helix def-"ine.s a generally cylindrical wall which, in use, consc2-cutes a proszrhetCi incralurnjnal wall.
The sinuous configuration of the wir- permints radial expansion and comp~ression of the scent; US--88GOO'2 discloses that the scent can be deliv, ered oercu:-anecusly and exoanded in situ usinq a balloon cacherer.
U.S. Pacenc 4,733,6605 discloses an expandable intral!Jminal grafrc wnich is cons cr-Lrured- by a rubular member formed from a plurality Of incerseccinig elongate members which permit radial excoansion and compressio-n of Lhe scent.
EP-A-05%585 discloses an iJnraluminal scentC whi~ch is constituted by a sinuous wire formed into a helixc; juxtaposed apices Of the -wire are secured to one another so Chat each hoop of thne helix is supporcred by its neighborin .000.:15 hooos to increase tne overall strengcrh oC Che scent and Co minimize the risk of olacrie herniation; in some embodiments the scent of EP-A-0556850 Eurcher comprises a cubula'r graft *member Co f-orm an endoluminal prosthesis.
The prior art scents and orosr'neses mentioned above are generally satisfactory for the Crearmnr of aneurysms, stenoses and other angeological diseases at sites in continuous uabifurcated oorcions of arteries or veins.
However, the prior art stenrs and oroscneses are not wholly satisfactory for use where the site of desired application of Che scent or proschesis is juxrtaposed or extends across a bifurcation in an arcery or vein such, for ex<ample, as the bifurcation in the mnammalian aortic artery into the common iliac arteries. or ex<ample, in the case of an abdominal aortic aneurysm in the infrarenal portion of EChe aorz-a which exrcenc-s intCo one ofl the com-mon :liac arteries, the use of nre cf r-he rroa--: proschesiS referred to above across the bifurcacion -incco rhe one iliac artery will result in obscrucc.Lon of che oro:u aL end of the other common iliac arc-ery; bv-oass Sur.zer'/ Is :he- efore i-equired to connecc the one iliac artery in ju:<capos-;zr-on t-!ich Che discal end oL che oroschesis to che oc*her- blocked iliac arrerv. It will be appreciated by a person skilled in the art Chat ir -Js 3 desirable to avoid surgery wherever possible; the requirement 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 Throughout this specification, the term "proximal" shall mean "nearest to the heart," and the term "distal" shall mean "furthest from the heart." 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 15 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.
Typically, the first stent may include a proximal ~male 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 n ortion =ay be tapcrCd radially inwardly towards its extremity. In some embodiments, the male engaging portion may comprise a frustoconical wall which flares JO 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 substantially cylindrical.
4 The male engaging portion of the first scent may be resiliencly compressible in a radially inwards direction such that in the radially compressed state it is capable of selfreexpansion to engage in the female cooperating portion.
Tvyically, each of said first and second scents may be resiliently compressible.
In use therefore che second scent may be delivered in a radially compressed state by using a cacheter; when the second scent is located at the site of use, the catheter may be withdrawn thereby allowing the second scent to re-expand to engage the endolumninal surface of the blood vessel.
The first scent may then be delivered percutaneously or by a "cut down" technique to a site discal of the second scent such that the male engaging portion of the first stent 15 in the radially compressed state is entered inco the expanded female cooperating portion of the second scent; 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 scent.
In some embodiments of the oresent invention the second stent may have two transversely spaced distal female cooperating portions; the second scent may therefore constitute a bifurcated scent for use in juxcaposition with a bifurcation in a blood vessel.
Each of the two transversely spaced distal female cooperating portions may be adapted for connection to a first male stent which, in use, extends across the bifurcation into a resoeccive one of the branched blood vessels.
In a oarcicular asoect of the present invention there is orovided a bifurcated intraluminal scent for use in juxtaposicion with an angeological bifurcation; che bifurcated incraluminal stent comprising a proximal portion adapced co be oositioned in service in a blood vessel in jux:<aposicion with a bifurcacion, a first discal scenc porcion adapted to excend across the bifurcacion into one of che branched blood vessels and a second discal scent portion adaoted to allow blood to a I flow from the oroximal portion into the other branched vessel.
The first distal scent portion may be formed integrally with the oroximal portion.
In some embodiments the second distal stent portion may comprise a female cooperating porction which is adaopted to engage a male engaging porcion of a another scent 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 intraluLninal stenit may therefore constitute a second scent in accordance with the oresent invention comorising a distal female cooperat:i 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.
15 Typically, the proximal end of said second stent may 'be flared radially outwardly towards its extremity to engage the endoluminal surface of the artcery thereby to resist longitudinal movement of the second scent in service.
SEach 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) w,ire 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 scent is intended to be used.
The scent may be annealed at an elevated temperature and then allowed to cool in air so that che nitinot wire "remembers" the configuration in which it was wound on the mandrel.
Said nict':oL wire may be cype nicinol wire which is arensitic at temperatures below: about 13 0 C and is austenitic at temperatures above about 25 0 C: it will be aooreciaced chereore that the oype wire will be austenicic at body ctemperaure oc 37 0 C. Tvoicallv, the annealing may be conducted at abouc 500 0 C or more Lor at least about 60 minuces; after cooling the wire may be iersed in cold water to facilitate removal of the wire _rom the mandreL 0 with the wire in its maleable mrcensicic form. Tvoicaliv, the cold water may have temoerature of less than abbouz 10 0
C;
the wire ma~y be immersed =for about 5 minutes or more. An advantage of using nitinol wire to fom th~e scant- in accordance with the oresent inventon is that: th~e nicino! -r is "Isuoer elastic" in its austenitic state; t*he radial out--ward force exertLed by the stent on the wall of the blood vessel in use is thnerefore substantially constant irrespective off the diameter of the vessel and the exoanded stent.
In some embodiments the may have a helical configuration as disclosed in EP-A-055-850. Atraiey the wire may be of an entirely novel configuration, namely one in which the wire forms a plurality of hoops such that tne olane of the circumference of each hnoop 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 complet-ed, the point of winding the wire may be displaced itudinally with respect to the windin~g axis to Form the next hooo. When the next hoop is complete, the poont of winding is moved further longitudinally with resoect to the winding axis to the form the next succeeding hoop and so on.
It will appreciated that an advantage of this novel arrangement is that the planes of the hoops are not skewed with resoect to the longitudinal axis of the stert; the longitudinal ends of the stent are I"scuare" to said longitudinal axis, so that when the .stent: is caused or allowed to exnand in situ there is substantially no twisting of the stent as it shortens in length. It: will be appreciat-ed t-hat this represents a significant advantage, as in areas of stericsis or aneur-ysm-, it is desir-able to r..J;m-ize tnhe r-ovemnt of the stenr: ithin the blocz- vessel so as to reduce the ootentiai trauma to the oatient. A stent ofL this configuration mayi be used, apart Ec-om c:he bifurcated embodiment- ot-herw,.ise t-aucnt herein, in, any aool caz.iofl -rc.
in stents generally have heretofor been used.
Typical!"y, th~e scents of this invencion .4nether of the helical or oer-jendicular variet-y, also comorise a securinz means for securing an aoex of the sinuous wire in one hoop to aJux<taposed apex of a neighboring boor) so that* each hooo is supported by its neighbors. The securing means may comprise a looo element of a suture material, f'or example, to tie tne juxtaposed apices together; the !oo element: may also comorise a loop for-med of a chermoolastics material such, for example, as pol vpropylene. Al1ternatively, the secur-ina means may be a bead Formed of a cher-moplascic material around j uxtaposed aoices. Also alt~ernatively, the securing means may be a loop, ring, or staple formed of w4ire such as nitinol.
The male engaging portion and female cooperating oortion., of the first and second interengagiing stents of this invent-ion, may be formed separately fror- t~e remainder of the resoective non-engaging portions of these stents and then the engaging and non-engaging portions secured to one another by securing means.
In one emtoodiment of the.Dresent invent ion, the proximal and distal stent portions of the bifurcated stent in accordance with the oresent invention may be formed separately; the distal end of the proximal scent portion may be secured to the wiider oroximal end of a first intermediate frustoconical stent: oortion; the narrow4er distal end of the 25 first inter-mediate frustoconical stent portion may be secured co the proximal end of the distal stent oortion. The female cooperating portion of the bifurcated scent may be constituted by a second frustoconical stent- port ion which is secured to the distal end of the oroxcimal stent portion in juxtapositioni *ith t he Eirst frustoconical portion.
Aiternativelv th e first and second_ Eruscoconical corcions may be omuzttec!; the oz-oximal and distal stent oortiorns may be secured directly (one to the ocher.
The ffem-ale cooperat-ing portion may be constituted b,.
a gene-rally cylindr-ical stentc porcion secured to said proximal stent poort_on irn nsverselv.. SOac!d -relati:L tO tnIe distal oort ion.
Each of the first and second scents of Che bifurcated form of the oresent invention may carry a tubular graft layer formed from a biocompatible fabric in juxtaposition with the scent; the combined scent and graft layer conscituting an endolu-minal proschesis. Typically the graft layer may be disposed externally of the stent; it will be appreciated however that in some embodimencs the graft layer may be disposed incernally of the scenc. In some embodiments the graft layer may be secured to the scent by loop elements such, for exampole, as loops of polypropylene.
The biocompatible fabric may be a polyester fabric or a polytetrafluoroethylene fabric; typically said fabric may be woven or a warp knitted polyester fabric. In some embodiments the woven or a waro knitted fabric may be formed in a seamfree bifurcated configuration as a sleeve for a bifurcated •scent.
In some embodiments the male engaging portion of the first scent and che female cooperating portion of the second scent may be left uncovered. Alternacively, the fabric graft layer may exctend 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 25 internally of the female cooperating portion to form a substantially blood tight seal.
The oresent invention in one aspect therefore includes a bifurcated endoluminal prosthesis comprising a bifurcated scent in accordance with the invention and a tubular graft layer.
Th ficrsc scent having the male engaging portion may also have a tubular graft layer-. I required the firsc oroschesis may be introduced in a radially compressed s.ate such chat the male engaging porcion of the irs oproschesis is engaged in the incer nediace c.ale coopea poorzo. fZbifurcated prosthesis; the first prosthesis is then caused to be allowed to re-expand in situ such that -he male engaging 9norcion eriaazes in cefemale coooeratjng oor-tion to resist longitudinal seoaratioi of the two prosthesis i~n service.
The bifurcated orosthesis may be adapted for use in the infrarenal por-tion of a malrtmalian aorta in juxtaposition with the bifurcation of the comrmon iliac ar-teries for the treazmenc of abdominal aortic aneurysms. in use the bifurcated endoluminal prostnesis may be introduced into the infrarenal portion of the aorta using a catheter such chat the first distal stent oor-on extends into one of the branched iliac arteries; the catneter may then be withdrawn allowing the or-osthesis to re-e:cparld in situ.
it will- be aoor-eciated by a oerson skilled in the art that the prostheses may be introduced to the site of use oercut-aneously or by "cut down" tecniques.
is P.:Y of the stents according to this invention may be o rovided on it excernal surface witch circumfr-entially soaced wire barbs or hooks adapted to engage in the endoluminal surface of tehost arter-,r to resist longitudinal movement 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 ooints of the artery which are engaged by the barbs or hooks are cover-ed by the fabric graft. it will be aooreciat-ed by a oerson skilled in the art that the traurn, to the artery wall caused by the hooks or barbs may cause e-,zoli; the orovision oL4 che fabric graft over the barbs or hooks in use will therefore help to prevent the introduction of such emboli into the blood stream.
Alternatively, the barbs may be sew.,n onto the out-side surfzace of the fabric.
The male engaging portion for the Cfirst stent: may be2 provided with circumflerentialiy soaced 'ook-s or barbs on its externaL surr ace to engaoe Thne ;nter-nal so rfice of' said fem-,ale cooperating means. thereb':, to reinffgrce teconnect ing means against longit-udinal secaration of the stents one from the ot-her in the se::vice.
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 endoluminal 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.
The aspect of this invention claimed herein provides an introducer for delivering, into the vasculature at an angeological bifurcation 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 l:i and a distal portion adapted to be disposed at least partially in one of said two 20 branched vessels said introducer including: i:e: a tubular outer sheath; a proximal portion pusher slideably disposed at least partially within said outer sheath and adapted to engage a distal end of said proximal portion; and 25 a distal portion pusher slideably disposed at least partially within said proximal portion pusher and adapted to engage a distal end of said distal portion.
"e*:The introducer optionally includes a balloon catheter, having a balloon attached thereto, said balloon catheter being disposed at least partially within said distal portion.
The invention in another aspect provides a method for delivering a bifurcated endoluminal stent or prosthesis having a proximal portion and a distal 11 portion into the vasculature at an angeological bifurcation where a blood vessel branches into branched vessels, said method including the steps of: inserting an introducer containing said stent or prosthesis into the vasculature to a predetermined delivery location, said introducer including an outer sheath, a proximal portion pusher, and a distal portion pusher; withdrawing said outer sheath of said introducer while maintaining said proximal portion pusher in a fixed position until said proximal portion of said stent or prosthesis is deployed from said introducer into said blood vessel; withdrawing said outer sheath and said proximal portion pusher while maintaining said distal portion pusher in a fixed position until said distal portion of said stent or prosthesis is deployed from said introducer at least partially into one of said branched vessels; and withdrawing said introducer from the vasculature.
This invention further provides a method 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 method comprises the steps of inserting an introducer containing the prosthesis into the vasculature to a predetermined delivery location, the introducer comprising an outer sheath, a proximal stent portion 20 pusher, a distal stent portion pusher, and a balloon catheter having a balloon attached thereto; inflating the balloon to at least partially block blood flow in the blood vessel; withdrawing the outer sheath of the introducer while .i" l i2 mainar'iig the proxi.mal scentc cortjon a snr i a ixed position until the oroximal otn ortion of r ep7-shss; deployed from tne introducer into the blood vessel; withdrawing the out-er sheath and the proximal stent porcion pusher -while maintaining t-he distal stent oorcion pusher in a f ixed position until the distal- stent, oort ion of the orosthesis is deployed from the introducer inco the blood vessel; and withdrawing the introducer from the vasculature.
Tn general, this invention provides a method of treating an angeological disease at a bifurcation site where a blood vessel branches into a first branched vessel and a second branched vessel compr ising the steps of disposing in the blood vessel a proxim.-al portion of an endoluminal stent; directing blood flow from the blood vessel -;nco tne first branched vessel through a first distal portion of the endoluminal stent, the first distal. oortion being connected to the proximal portion and extending into the-- first branched *vessel; and direct-ing blood Flow from the blood vessel into ~:the second branched vessel through a second distal oortion of the endoluminal st-ent, tne second distal corcion beina *connect ed to the proximal port ion and extend-i ng into the second branched vessel: This method may be aoplied to aneurysms, occlusions, or stenosis.
?'ollowing is a descriptilon by w:ay of example only a~id- with reference to the accompanying dra-,winqs of the coresenc: invention, including novel stent cons tructions and methods of manufacture and use thereof.
BRJEF DESCPRT2TrIuON 07 L..
The asoects, features and advantages of the present inventinnwl be more readily understood frm he fOolowis dct4.iled Hiescrioti-on wheni read in conjunction- with the accompanying drawings, in which: Figure La is a front- vie-., of a bi-f u.cat~ed intralumilnal stencz in accordance with the oresent- invent ion constituting part of an endoluminal orosthI-esis.
I
1 3 Figure !b is a frontc view off another stent- which is adapted to be connected to the bifurcated scent of Figure la.
Figure 2(a) is a side view of parz of the bifurcated stent of Figure !a opened up to show its construction.
Figure 2(b) is a side view o' ar. exemplary mandrel used' to form th'e oar. of the bifurcat-ed stent shown Ficure 2(a).
Figure 3 is a side view of another Dart of tnebifurcated stent of Figure !a opened up to S'now it~s construction.
Figure 4(a) is a side view of yet another Dart off the bifurcated stent or Figure la ooened uo to show, its cons truction.
Figures 4(b) -4 are oartial exoloded vie- .s of the 1 5 exemplary stent off Figure 4(a) illustrating alternative means for securing juxtaposed apices according to t peet invention.
Figure 5 is a schematic perspective view of a bifurcated endolumrinal orosthesis in accordance witch the oresent invention.
Figure 6 is a schematic view of another bifurcated endoluminal oroszihesis in accordance with the oresent invention.
*..*Figure 7 is a schematic view of yet another :25 bifurcated endoluminal prosthesis ini accordance with the oresent- inven: :Lcr.
Figure 8 is a cross -sectional view off an exemplary assembled introducer according to the present invention.
Figures 3 -S3(e) are side views off t-he componenit oarts off the inzroducer of F-igur:e 83(a).- Fiu8 8( f) is a oarti-ai cross -sectional view oE the introducer ot Fi-cure 1; Figure aCg) 4 S a Cross -seCrjional view' Of :Darr oC Of Z ricrodiJcer of Fi4gaure (f r-aken a! onc tb.e 1 i A -A.
Figure 9 is a side cross -secciona- view ofE a portionan altzernative embodirnen:c off an intcroducer according to, th-e oresent invention.
Ficures '0(Ca) and 10(b) are side views of och-er aiternacive embodimen _s of an introducer according to r-he oresenc invention.
Figures chrough 20 are searuential cross -secional views off the bifurcation or the abdor-'.ial aorcic arcery curinc introduction ofr an exempla.-y, prosr-hesis according to ctne oresentC _:nventlon.
F7icur.:es 2l(a)-21(c) are cross-sectional veSof alternative insert-ion aooaracus according to the oresenc invention.
Figures 22 and 23 are side views of alternative *sterits according to thre oresen: in-verition.
Figures 24; Ca) 24t 25, 2'0 and 27 are seauenct ial *cross-sec Lional views of the 'ifurcat i on o4: the abdominal aortic arteryI during introduction of an exemplary prosches-is according to the oresentc invent~ion.
Figures 23 and 29 are cross- sectional side views of alternae:ive delivery aoparat-us according to the present.
invention.
Figures 30-34 are secuenitial. cross -sectional vuiews c;f t he bi:f ur c a ziLon or ff he a Id o 7 'n a az)r _I*c arter du rJin C introduction of an exemolary/ prosr-hesis according to Cne oresent invention.
DET:\ffED 0OESCRPL The oresen t invent__on Cies anar-atus and rmet-hod ffor treating angeologicalI diseases in any bi.furcated blood 'esseL. One exa mile o~f such a biffu.-cacted blood vessel :s the Inrfrarenial oortion or a ma~nlacz orLic arcerv whnere it.
bifur-cates to th'e co.'mo:. iliac: aterties. Exi::oles of diseases that can be created us-in ch'e apparacus and mecnod of the oresent invention include aneurysm, stenosis, and occlusio.
A bifurcated stent in accordance wich the present -invention which is indicated at 10 in Figure !a comprises a wire skeleton which is constr-ucted in -Four separate parts, namely a oroximal part 12, a first Erustoconical part a fEirst d-istal part 16 and a second Efrustoconical parc 18. Said bifurcaced scent 10 carries a -Fabric grafft laye-- (Figures 6and 7) for use as an endolurninal oroschesis e.g. in tne infrarenal portion of a mar-amalian aorta Juxtaoosition wit-'.
the bifurcation of: tnle common iliac arteries It wn:ll be aooreciaced, however, that bifurcated scents (with or without fabric graft layers) for use in diffferent parts cme angeological system and for different rnamals can be is..1 constructed in accordance with t.he invention by varying che dimensions of the scent accordingly.
Each of the four parts of= the bifurcated scent 10 is made in substantially the sa-me way by winding a saememory nitinol wire, t-voically nir-inol type ~M wire, onto a mandrel 46.
The const-ruction of the exempla ry proximal part 12 of the bifurcated scent 10 is shown in Figures 2(Ca) and 2 n~tnolwire ty-pe Mi wire typically having a diameter of 0.46mm, (0.018') is wound arounda mandrel 4'j to form a olurality of hoops 20. The winding surface of mandrel is orovided w I z a plurality of upstanding pins 47 disposed in a zig-zag pattern for each of the hoops 20 sotchat in each hoop 20 the nitinol wire follows a sinuous oath to deffine a pluralit y of circumferentially spaced apices 22. Each hoop 20 is wound onto mandrel 46 such that the plane of the circumference ot each hoop 20 is subscanrciall ocroendicular- co the iong icud inaL xs oJ the amand~e 1 ',-hen one hoco 20 e.g. the hooo indicated at 20a has been 'ormed, the Doitc of windinq of the nitinol wir e is displaced long itud inally wicth resoect to) Lhe axis of m-,andrel.
46 to form the nexr: successive hoco 20b. ThMe stent shown -igure 2(a) is the stent ftormed on miandr-el 46 shown in Fcr 1 2(b) after cutting the scent longitudinally and rotating it degrees to show the construction of the stent.
The proximal part of the exemplary bifurcated stent of Figure la is formed on the mandrel with a diameter of about 24mm and a length in the longitudinal direction of about From Figures and 2(b) it will be noted that the proximal part 12 is constituted by three hoops 20 of unit width.at the proximal end 24 of the proximal part 12, two intermediate hoops 25 of twice unit width and, at its distal end 26, by a single hoop 20 of unit width. in the illustrated embodiment, intermediate hoops 25 have a plurality of offsets Offsets 25a are formed when the wire is passed around pins 47 on mandrel 46. Offsets 25a add stability to the stent. When the nitinol wire has been wound onto mandrel 46, 15 the nitinol wire is annealed at an elevated cemoerature and then allowed to cool.
In this embodiment of the invention the wire is annealed at a temoerature of about 5001C for 60 minutes and is Sthen allowed to cool in air. The purpose of the annealing is so that the nitinol wire in its austenitic form "remembers" its configuration as wound on mandrel 46; it will be appreciated therefore that other temperatures and durations for the annealing are included within the present invention provided the nitinol wire "remembers" its wound configuration.
Aft.er annealing and cooling, the wire is immersed in cold water at less than 10,C for about 5 minutes; the wire is then removed from the mandrel, and juxtaposed apices 22 of neighboring hoops 20 are secured together by securing means 99 (see Figure which are, in this example, 0.003" polypropylene filaments. Each apex 22 of each hoop 20 which has a juxtaposed apex of a neighboring hoop 2. is tied to rhe juxtaposed apex 22. It will ;e appecacted, ;,owever, that in other embodiments of zhe inver.ion only some of the juxcaposed apices 22 may be secured in this way.
In addition to polypropylene filamencs, the securing means mray comprise a loop element 99a of a suture material, Lor example, to tie the juxtaposed apices togecher, as shown 17 in Figure The securing means may also comprise bead 99b formed of a thermoplastic material around juxtaposed apices, as shown in Figure Also alternatively, the securing means may be a loop 99c, ring 99d, or staple 99e formed of wire such as nitinol, as shown in Figures and 4(f) respectively.
The exemplary first and second frustoconical parts 14, 18 of the skeleton shown in the figures are formed in substantially the same way as the proximal part 12 by winding nitinol wire onto a mandrel and then annealing the wire before removing it from the mandrel. As shown in Figure 3, the first and second frustoconical parts 14, 18 are each constituted by three hooos 20 of unit width. The mandrel is tapered such that the proximal end of each of the exemplary frustoconical parts 14, 18 is formed with a diameter of about 12mm and the distal end 32 of each is formed with a diameter of about 9mm.
The overall length of each of the exemplary frustoconical parts 14, 18 is about 18mm. The wire used for the frustoconical parts 14, 18 is nitinol type M wire having a diameter of 0.28rmm Juxtaposed apices 22 of each of the exemplary frustoconical' parts 14, 18 are tied together using 0.03" polypropylene filaments as described above. The first and second frustoconical parts 14, 18 are secured to the distal end 26 of the oroximal Dart 12 of the stent 10 in transversely spaced relation as shown in Figure la by securing the apices 22 of the hoop 20 forming the wider proximal end of each of the frustoconical parts 14, 18 to juxtaposed apices 22 of the hoop 20 on the distal end 26 of the proximal part 12.
The exemplary first distal part 16 of the bifurcated stent 10 is formed by winding nicinol type wire typicall.y having a diameter of 0.28mm onto a .andel to form twelve longitudinally spaced hoops 20 as shown in Figure 4; the exemplary first distal part has an overalL length cc about 66mm and a uniform diameter of about 9rm. The proximal end 34 of the discal part 16 is secured to the narrower distal end 32 of the first frustoconical part 14 by tying each apex 22 on is the oroximal end 34 of the fi.rst dis, al parc !6 to a juxtaposed apex on tne disca1 end 32 of the frirsc rruscoconical oart, 14 using, in this ernbodiment, 0.003", polypropylene filaments.
The proximal oarc 12, C-he ffirsc and second fruszoconical oarcs 14, and th~e Eirsc discal carc lG are each covered with a tubular grafrC laver of a bioccrmoat jhle woven. fabric (Figures 5, 6, and 7) such, for example, as a plain woven fabric made from 30 or 40 denie, oolyescer. Tjhe tubular fabric layers may be attached to the proxim.al and disral parcs 12, 16 of the scenc 10 s~i-ch-nn wich, for example, 0.003" polypropylene filamnents around Che apices 22 of t'ne underlying skeleton. The Eabric covered scenc constitutes one Eorzm of an endolurninal prosthesis.
15 The oz:-oximal oarc 12 of the wire skeleron may be *orovided with a plurality or circumferentially spaced hoo.ks or barbs 43 which orojecr through r-he tubular fabric laver to **engage in the endolum-inal surface of a host arcery, in service.
The sinuous configuration of each turn 20 of the wire skeleton of the stent 10 allows the orosthesi.s to be comoressed resiliently -radially inwards so that it can be received in a catheter e.g. a 16 or 18 French% catheter for percutaneous or cut down delivery, e.g. t-o an int-raluminal site in the infrarenal section of the aortic artery. La rge r diameter cathete:s up to, 20. French, be used to deliver the prosthesis using "cut down" procedures.
Akn x-ray opacrue marker may be attached to one or more ends of a scent so that the delivery of- the scent can be monit~ored using x-rays. As shown in Figure 4 such a radiooacue marker- maI tyoica lyv comorise a cold or platzinum wi.re 17 crir-:oed onto ai, end ofE stenc 16. Alte2rnativeley, z-he radiooacou, mar'-e-- may be a tube. i7a disoosedj arouno a lenccth of -ire on The sLr n> also as show-n i.n icjur-2e, (a) Tvoicallv, in The bifurcated stent: the makris secured to The stent in line with the distal stenL porZ~on so c"hactThe distal szenc cortion can be al icned ith and inserted into one off the branched arceries in situ.
19 The bifurcated endoorosthesis is Positioned in the infrarenal section of the aortic artery in juxtaposition wijth the bifurcation of tne comu~on iliac arteries such chat the First distal part !6 of the orosthesis extends into one ofL the common iliac arteries. The catheter is then witnodrawn allowing the stent 10 to re-excoand towards ics configuration as wound on che mancre. in which it was annealed until t'ne stent engages thle endolumlinal surface of the host artery. The barbs or hooks encage the endoluminal surface of che host artery to resist long itud inal disolacernent or- sliooinc; of the prosthesis in use.
7 t will be aooreciated that when the bifurcated orosthesis is oosictioned and re-exoanded in :he fitted oosition, blood can flow from the aortic artery into the oroximal oart 12 of the oroscnesis from where it can flow into .e..the one common iliac artery through the frusm:oconical part 14 and the first distal oarc 10' and also into the other common *e iliac artery through the second frustoconical part 18.
in cases where ic is required to imolant a prosthesis in the ot-her comnmon iliac artery a second orosthesis comor is-4ng a second stent 40 as sn'own in Figure lb can be used. The second scent 40 includes a wire skeleton compris ing a prox(imfal fristoconical parzm 42 and a distal part .44. The distal part q4 of' the second stent 40 also may be L covered wdith a tubular graft layer of a biocomoatible fabric such, for examole, as polyester or polytetrafluoroethylene :9:9 abric (Figures 5, 6, and 7).
The frustoconical proximal oarc is constructed in the same w.,ay as the frismoconical parts 14. 18 of the bifurcated stent the distal part qe is contstructed in the same way as the distal oart J: ol the bifurca.red scent he distal end of thCruszuconical or-oximal par 42 is secured to the or-oxiatal end of the distal oarc 44; by securing juxtaposed apices using L''orolei ilamz.its as descr ibed abov.~ rn use, rm, secon.d oos zhe S;s i s ccoore s sed rjdia inwards and is received in a catheter f-or- oercumaneous or "cut down" deliverry to the ocher common iliac artery. h e frustoconical oroximal part 42 is guided, in the radially compressed state, into the second ff-ruscoconica! part is of thie biffurcated scent 10. The catheter is chen withdrawn allowing the second scent 40 to re-exccand towards its rememb'ered conf iguration, until the distal oarc 14 engages the endoluminal surface off the ocher comon ili:ac artery, arnd the outer surface of the fruscoconical proximal part 42 engages the interior surface off the second fruscoconical part 18 of the bifurcated scent: As with ocher scents described herein, trie Lruscoconical -rxm arc 4'2 may be fora-nez w.4icn circtirnferenially spaced barbs or hookzs 43, as shnow~n in Fjaure ib, w4hich engage in the -wire skeleton off the second ffrustoconical cart 18 of tne bifurcated scent 10. Wdhen barbs 43 are on proximal portion 12, they engage the inner wall o;7L 00:0the arcerv.
The capered conifiguracions off the second fruscoconical parc 18 o: crie oifurcated stent 10 a nd off the proximal fruscoconical part 42 off the second scent 40 are Such that in the ite oiinadscidthe prosthesis are locked together to resist longitudinal separation in ser-vice.
Barbs or hooks on the second scent 40 and/or an frustoconical proximal part 42 helpcto resist sucn lon~gitu1dinal separationt.
in another :.xasnole off the present invent ion a **bifurcated endolum-inal prosthesis 50 as shown in Figure includes a bifurcated scent comprising a pro:<imal, oortion 52 *which taomers radially in-.artly ffrom its crocxim;-,al end 54, to icz distal end 56, and ffirst and second transversely spaced fruscoconicai distal oor:cions 58, 60 which are secured to the distal end 56 off the oroximal portion 52: rt-: oroximal rort;.
52 is cover-ed with a zi-jbuLar Lara: laer oL' a bircomoctibLe ffabric 62.
Tuse the orosthesis is deliver-ed cercut-aneous ly or zv Z13' arterial biffurcation; blood can flo%,w through~ the fruscoconical crox imalI or Li on 52 into each of tebranched artieries throuch th'e first anid second distal fr-ascoconlicai parziors 58,6o a prosthesis is recuired in one or both of tebran.ched arteries, a separate proschesis comprisi.ng a scent of the ci/oe shown in Figure lb referred to above covered with fabric can be connected to the bifur-cated prosthesis 50 isertinz: and re -expand-ing the oroximal end of such a separace prostnes-'s in one or both of the dista. frustoconical Dortions 5E, 60 of th orostnesis 50 for engagement therein.
?Lnother variant of the oresenc invention is shownl in Figure 6 which shows a bifurcated endoluminal orosthe--sis having a proximal oortion 72 which is secured at its distal end 7-4 to 57spaced fruscoconica-Intreae portions 76, 78.
One of said frustoconical intermediate Dortions is secured at its discal end to an elonzate distal portioi S0.
so.. The oroximal end 82 of the proximal portion 72 is flared radially outwards towards its proximal end 82 to engage tne incraluminal surface of che host blood vessel in service.
we. Save for this flared oor:ion, the encire erdoprosthesis is covered with a fabric graft layer as shown in. Figure 6; said graft layer is carried externally of the wieskeleton anc is folded over the distal ext-remity 84 of the other f~rustoconical intermediate oor:ion 78 to form an internal lining in said otner frustoconical imxediate oortion 78.
e.25 Said other fr-ustoconical intermediate portion 78 constitutes a female cooperat ing portion in accordance with the present invention which is adapted to receive a male engaging ortion off another prosthesis as indicated at 86 in Figure 6. Said ocher prosthesis 86 includes a frustoconical proximal portion 88 which constitutes the male engaginportion and an elongate dist-al oorcion. 90. The whoLe ofT chc Z other oroschesis S6 is covered wiha f:.b--ic qr,.aft laver as shown in F-igure 6. In ser:---ce, the male engaging portion S8~ off the other arosthesis 3- is entered int-o a.nd engaged wt the fet,,ae cc-rtn ort!.;on 73 off th L1r-edno2~e~ in situ in the manner herein before described. The Cabric layer on the mnale encacino oortion 83 but-ts Zace- t--face on1 -22 the -,-old ed over port ioni of the f abric I a.yer di4so osez4 internally o4f the female cooperating portzion 78 to for-m a subs tant iall1Y blood-tight seal Cherewitn.
Yet another exa-mole of Che oresenc ivention is shown' in Ficure 7 in which a bifurcared endoluminal prosthesis 91i i a s a generally cylindrical proximal portion 92; said proxi mal poortion 92 is connected at its distal end 93 L~o a~ elongate, generally cylindrical discal Dorcion 94;. Said oroximal oorcion 92 is also connected at it-s distal end 93 to a generally cylindrical inter-mediace portion 95 which is secured in transversely spaced relation to the elongate disr-a± portion 94. Said cylindrical incr-mLediate portion constitutes a female engaging port-ion which is adapted to recei.ve a generally cylindri cal male engaging portion of a .15 second elonate prosthesis (not- shown.). The male engaging cortion is ecu-iooed with circurnferencially spaced externail *barbs to engage in the fernzle coope rating porcion in service.
As shown in Figure 7, the whole of the bifurcated oroscnes-is 91 is covered with an external fabric graft layer save for a flared portion 96 towards che oroximal end 97 Of the proximal ion 92.
Refferring to :Figures 8 -8Ef) an exemolary embodiment of a delivery system according to the oresent invencion will be described. This system is used to deploy S: the bifurcated stent- 10 *jhe=n it is covterd with a fabric graftlayer to create an endo-luiinal prosthesis. Introducer 100 includes outer sheath 101. Outer sheath 101 is a cylindrical tube adapted to be inserted either ner*cutaneously or- I-),cut/ down" procedures into the vasculature from an entry point to the bifurcation site w-here the o~rost-hesis is to be deployed.
Housed 'izr.outer sheatch 10I is or-oximai o~o zcshe: 102. Proximal ort iori ousher 102 is a cvlindrica*i zu havinc an outside diai-neter smialler- than the inside dia,(V ter 01.
outer sheath 101. Proximal portion ousher 102 is or-efcerabIlv silidable t-hro CU C h -1 o0 OS":2, Disposed 00hi:-Lim1ootion ou-sher 102 is distal Oort-ion Ousher- !03. Distal ort-on cusher 103 i;s a 23 cylindrical. tube slidably concianed wruhn distal oorcion ousher 102. Distal oorciol pusher 103 is preferably adapted to slide throughout the entire length of proximal portion pusher 102.
Disposed wichn discal portion 103 is balloon catb..erer 104. Balloon catheter 104 is adapced to slide wichlip.
distal oortion ousher 103. At the leading end 105 of balloon cathe :er 10q iJs nose cone 100'. Balloon 107 is attached to balloon catheter 104 between nose cone 106 and oroximal end 115 of proximal oort ion ousher 102.
As s-own in Ficure 83(g), which is a cross -sectiJonal view of balloon catheter 104 in the direction A-A off Figure balloon catheter 104 has a guide wdire conduit 104a.
Guide wire conduit !04a. extends throughout the length oF balloon catheter J.04 for passing a guide wire (not shown) through introducer 100. In the illustrated embodiment, balloon catheter 104 also includes injection orifice 109 and an injection conduit 109a. Injection conduit 109a connects injection orifice 109 to an injection site 108 at or near the 20 distal end- of balloon cat~heter 104 as shown in Fig. 8 00.0Radiopaque liqu id may be injected into injection site 103, 0 through injection conduit !09a, out- injectioni orifice 109, and into the vasculature to monitor deploymentz of the prosthesis.
0 Also in tne illustrated embodiment. of Figures 8(E) and 8 balloor. catheter 104q has an inflation orifice 110 located at a ooint where balloon 107 is attached to balloon catheter 104. A balloon inflation conduit 110a connects balloon infElatio o:-r'iFice 1 10 to bal!loon iilat ion s ite I1 (Figure Balloon 107 may be inflated and deflated from balloon inflation site 111 during delivery of the prosthesis in an alternative embodiment llu rrced in Fig. 9.
seals 150, 15.1. be disoosed around the di'stal ends 16~0, 161 o" oucer sheath 10 and pr-oximal portion pus'hec 102. Saals 150, 151 ma'y be fo:m-ed of silicone- tubes.
Fig. 10(a) shows an alternative embodiment of inr cr100. A's sho':. in 112 and 113 ar:2 2 provided at the distal end of introducer 100. 'elirn 112 is connected to oroxima1 oortion ousher 102, and winc 113 is connected to outer sneath 101. Wings 112 and 113 indicate tne rotational orientation Of DroxiMal portion Ousher 102 and outer sh~eath 101, respectively. This in turn indicates trte orientation of Proximal oortjon 12 within outer sheath 101 and distal oortion 16 within oroximal oortion ousher 102. leinoCs 112 and 113 in the illustrated entbodiment are also oroviced with holes 1!2a and 113a.
As shown in Figure 10(b), a rod 123 or ocher fixation device may be attached to wings 112 and 113 usina e.g. bolts truhholes 112a and 113a secured oy wing nuts 129 or other securing means. Rod 128 orevents relative movement of oroximal oortio n pusher 102 and outer sheat-h 101.
wings may also be provided on distal portion ousher 103 and used to secure distal portion pusher 103 to either oroximal portion pusher 102 or outer sheath 101 using a fixation device as described above.
oes. Al1so shown in F.ig. 10(Ca) as part. of introducer 100 o 0 -020 is hemostasis valve i11. Hemostasis valve 114 is connected to 0 o~eo distal portion pusher 103 and acts as a simole seal around oe balloon catheter 104 Altchough it orevents Eluid loss, hemostasis valve 114 allows balloon catheter 104 to slide 0000 within distal portion ousher 103. Alternatively, a Touhy- Borst valve Cnot showrn) may be used instead of hemostasis valve 114. The Touhy-Borst valve is a device that may be manually tightened over balloon catheter 104. Lightly tightening such a valve permits balloon cath'etcer 104 to slide; firmly tightening such a valve clamps balloon catheter 104 in place.
In use, the proslhesis must Eirst be lnaL..ed into introducer 100. Outer sheathn tir-ct oved Eromn inuroducer 100. Sailor-n cntchet-2r 104 is the- threaded through distal portion 165 and proximal oort-ion 12 of the orosthesis.
The orosthesis is then cooled to a_ teroerature oL apooximately 10'C or below and radially compressed. Fo. this ou roose, the prosthkesis may be immersed in. Cold wae.Th'e 25 orosthesis should pre-ferra-bly remain. in the water- duri,- loading operation.
As suaaorcing stent 10 is compressed beneath the fabric covering of the prosthesis, excess fabric is oroducec-.
This excess fabric mayv simply be pinched together and laid over the comoressed prosthesis in longitudinal folds.
Distal Portion 16 Of the orosthesis in- the radiall', comoressed state is then inserted into oroximal oortion ousher 102. Outer sheath !0I is then oulled over proximal oortjon 12 of the orosthesis and over oroximal oortion ousher 102. PA nhea (o t s hc ce atche to t- :D r o -n-4 C proximal portion 12 of the prosthesis and threaded through outer sheath 101. This thread may then be used to pull *proximal portion 12 through outer sheath 101. During the loading process, it- 'L important to keeo Droximal portion 12 and distal portion 1S of the orosthesis properly aligned witn *outer sheath 101 anrd proximal portion pusher 102. Marks may be placed on the outside of outer sheath 101 and proximal portion pusher 102 to ensure proper alignment.
Refer-ring again to Fig. the prosthesis is inserted such chat the outer surface of proximal portion 12 contacts and is radially restrained by outer sheath 101, and the outer surface of distal portion 16 contacts and is radially restrained 'bi proximal portion pusher 102. rEIid 115 of proximal portion pusher 102 longitudinally engages oroximal portion 12 of the prosthesis as shown in Fig. 8(f).
Balloon catheter 10e, is oositioned such that nose cone 106 just clears proximal end 117 of outer sheath 101.
The introducer- is now in condition for insertion into the patient.
PRee-rring tc r'ig. irit,'oducec 1003 is g~assed throuch an entry point (not sho-- n) either in the patient 's skin (oercutaneous operation) or i'nto the vasculature ltselt which has been surcicall exoposed ('cut -dor.'n operation).
lntroducer- 100 is inserted over a guide wire 170 into the 25 vasculature from tne en:ry point to the desiredi deiverv location at an angeological bifurcation.
in the aorta, introducer 100 is positioned such that end 117 of outer sheath 102. is aoproxiLmately level with rena arteries 1-80 as shown in Ficure 11. Balloon cac;h,.- 10a is then-extended wnile maintaining outer sneath 102.1 a f ix:ecposition. Balloon cac heter !04 in this embodimenc is nd e until distal end 105 of nose cone 1006 is aooroxima:elv 35 mm:above tne proximal tio 117 of outer sheath 101.Thn ie 0 maintaining proximal portion pusher 102 in a fixed oosicion, outer sneath 101 is withd-r--aw-n until the oroximal c-'o of tnhe orosthesis is level with oroximal Ctio 117 of outer sheath 101.
Tr will be noted that balloon catnecer 104 does noc move while outer sheath 101 is so withdrawn.
Introducer 100 is then rez3itioned to Place the prosthesis in the desired deolorment- location. Prooerplacement may be facilicaced with the use of radiopaque markers as described above. Balloon catheter 104 is then extended such that balloon 107 is above renal arteries 130.
Balloon 107 is tnen. inflated to occlude the aorta as snown in Fi. 2.
leraile maintaining proximal portion pusher 102 in a Lixed position, outer sheath 101 is withdrawn until the oroximal end of the proschesis emerges from outer sheath 101 as shown in Fig. 13. Using a radio-pqcue marker 120 disposed on oroximal end of the prosthesis, the introducer is rotated until proper alignment- of the orosthesis is obtained. In the illustrated e,-uoooimenc-, radiopaque cmar-ze:- L20 Is a tn: wire twisted around an apex of the orosthesis in a V"shape.
To ensur-e orooer alicnii-ent. tne stent should be rotated until only th~e oroF-:Ile of t-he 11 is seen and shows uo as5 a srzraiht line ran.than a Outer she -ath !01 is Eurther ihdan hl mainca-ining proximal ort-ion oushier !02 fixed until 0roXima,,:l portion 12 is fully deployed fr-om teend of outer shLeath 101.
and. the frustocornical pootizon IS off the prosthesis just clears end 117, as shown ir. 'icure 27 Balloon 107 is then deflated to allow blood to flow through proximal portion 12 and out frustoconical portion 18 of the prosthesis. Balloon 107 is withdrawn into the prosthesis until the distal end 118 of nose cone 106 is just above the proximal end of the prosthesis. Balloon 107 is then inflated to seat the prosthesis, which may be provided with barbs (not shown) at its proximal end, against the wall of the aorta, as shown in Fig. Distal portion ousher 103 is then maintained in a fixed oosition while outer sheath 101 is withdrawn. Once outer sheath 101 has been withdrawn to the ooint at which proximal end 117 of outer sheath 101 is flush with oroximal end 115 of proximal portion pusher 102, both outer sheath 101 i. and proximal portion pusher 102 are withdrawn, still maintaining distal portion pusher 103 in a fixed position.
Outer sheath 101 and oroximal oortion ousher 102 are withdrawn Suntil distal oortion 16 of the orosthesis is deployed clear of proximal end 116 of distal portion pusher 103 as shown in Fig.
16. Balloon 107 is slowly deflated to allow blood flow to be established through the proximal porcion 12 of the prosthesis and out through frustoconical portion 18. Balloon 107 may be used to model distal portion 16 of the prosthesis as necessary by inflating balloon 107 where needed to expand distal portion 16. Balloon 107 is then deflated, and introducer 100 is S. withdrawn from the vasculature, leaving the guide wire 170 in place, as shown in Figure 17.
Figure 21(a) illustrates an exemplary second introducer 300 used for deploying second distal part '4.
Second introducer 300 of the illustrated embodiment comprises cylindrical outer sheath 301 and female Luer lock assembly 310. Second introducer 300 also has hemoscasis valve 361 contained within r:u 362 chereof. Carcridge 311 shown in Fig. 21(b' is adapted to be attached to second introducer 300.
Cartridge 311 has threaded male Luer lock assemb v 3L2 provided on i-ts pc:-ia d. Cartridce 311 has outer tube 313 which houses inner tube 3-14.
23 7~n use, a Chi ailed tube (noc shown7) i s f;irsc threaded through distal portion 44. This tube ser-yes as a gu iae wire guide, allowing a guide wire to be threaded straight through distal portion 44 as discussed below. Distal oortio' 44 containing the cnh.n-walled cube is Chen cooled, radially compressed, anc inserced inco inner cube 314 of cartridge 311 in a manner similar to that. described for inserting the bifurcated prosthesis into oroximal' oorcion ousher !02 and outer sheath 101. When distal portion 44 has been loaded into inner cube 31q oE carcridge 311, the thinwalled tube ser-ving as a guide wire guide exten-ds out bot ends cartridce 311.
A guide wire 171 is then inserted into the vasculacure to the bifurcation site and through distal scent 5 orion 12 as shown in Fia 18. A dialacor 359 (Figure 21(c)) having an outer dia-meter slightly less than the inner diameter of second introducer 300 is then inserted into second :int.roducer 300 such cthat taoerec end 30'0 extends out end 320 oE second introducer 300. End 360 of dialacor 359 has a hole 20 therein Chat is just slighcly larger than guide wire 17.1 and taoers gradually outward from the hole co the outer diameter of dialator 359.
Second introducer- 300 is Chen inserted into the vasculature over guide wire 171 by passing yiuidzle wire 171 inco 5 and through dialator 359. Dialator 359 tapered end a smooth transition within the blood vessel from the diameter of guide wire 171 to the diameter of second irod!ucer 300. Second nroue 300 is mne2';,.ered suc n: outer sheath 301 is inside Erustoconical portion 18 of proximal portion 12 by at least 20 i~ n this embodim-ent, as snon -ig. 19. DialaCor 359 is then removed from second Lntrcducer 300 and from the vasculacurcr and isdcrK.
Cartridge 311 is then pass. d over- cuide wire 171 by paissing guide 71 thr-ough che zhin-w alled c;uide wi,,re rA noto cItane in,: cride 3 11.
The guide wire cuide is then removed and diLs car:ded.
29 Cartridge 311 is then lockingly engaged with introducer 300. by mating male Luer lock assem~bly 310 with female Luer lock assembly 312. Such locking engagement prevents relative movement of cartridge 311 and introducer 300. Preventing relative movement lends stability and reliability to the insercion process that has not heretofore been achieved.
A pusher 315 is then inserted into inner tube 314 of cartridge 311 such that proximal end 317 of pusher 315 longitudinally contacts a distal end of discal portion 44 within inner tube 314. Pusher 315 oushes distal oortion 44 through cartridge 311 and into outer sheath 301 of introducer 300. Distal portion 44 is oushed through outer sheath 301, which remains in a fixed position, until distal portion 44 is 15 at proximal end 320 of outer sheath 301 (see Figure 19) Again, radiopaue markers 120 may be used to align distal portion 44 properly with proximal portion 12.
Pusher 302 is held firmly in place, and outer sheacth 301 is withdrawn aooroximately 2 cm. This deploys 20 frustoconical oart 42 of distal part 44 inside the frustoconical part 18 as shown in Figure 19. The outer surface of frustoconical part 42 engages the inner surface of frustoconical part 18 such that distal portion 44 is connected to proximal portion 12 to resist longitudinal separation.
25 Outer sheath 301 may tien be withdrawn while maintaining pusher 302 in a fixed position to fully deploy distal portion 44, as shown in Figure 20. If necessary, balloon catheter 104 may be inserced through sheath 301 in order to model distal portion 44. Introducer 301 and giuide wires 170, 171 are then removed from the vasculature and the entry points are closed.
The delivery apparatus and method described above are particularly useful in cteating an abdcminal aortic aneurysm with a bifurcaced prosthesis according to the oresent invention. Other diseases and alternative embodiments of che prosthesis and delivenr method w:ill now be described.
In the case of an abdominal aortic aneurysm confined to the aorta and not excending far enough to affect the iliac arteries, a straight non-bifurcated) scent may be used.
Preferably, for such applications, the straight stent comorises a composite of at least two axially aligned scent segments. Two embodiments of such straight stents are described herein, each comprising axially aligned scent recuests, each of the requests comprising one or more adjacent hooos, oerpendicular to a common axis, and each hoop being formed of wire in a sinuous or zigzag configuration with some or all of the juxcaposed apices in adjacent hoops secured to one another..
First, referring to Figure 22, straight stent 400 comprises proximal stent porcion (or segment) 401, distal 15 stent oorcion 402, and an intermediate portion 403.
Proximal portion 401 is a ring formed of a number of longitudinally spaced hoops 20 as described in connection with the formation of stent 10 above. In the illustrated embodiment, two hoops 20 are used, each hoop 20 having a unic 20 width.
Distal portion 402 is also a ring formed of longitudinally displaced hoops 20 in the manner described *99 above. Distal ring 402 has two hoops 20 of unit width in the illustrated embodiment.
Intermediate portion 403 of straight stent 400 is formed of biocompatible woven fabric such as, for example, a plain woven fabric made from 30 or 40 denier polyester. In this embodiment, intermediate fabric section 403 does not cover a stent. Fabric portion 403 is attached at its proximal and distal ends o, the proximal and distal scent porcions.
respecr ively, by scitchingc for example, with 0.001 inch polyp.opylene filaments around apices 22 of the stent portions. Other than such connections at its longicudinal ends, incermediate fabric section 4;03 is unsupported by any stent.
The second embodiment of a straight stent that may be used according to this invention is illustrated in Fic. 23.
Straight stent 450 includes stent portion 451, constructed of wire loops as described above with reference to scent portions 401 and 402. Stent porcion 451 is partcially covered by fabric 452. In this embodiment, fabric portion 451 covers and is suoopported by stent 451, whereas with stent 400, the fabric portion 403 is not suooorted by a scent.
To treat an abdominal aortic aneurysm that does not extend down over the walls of the iliac arteries, as shown in Figure 24(a), straight stent 400 (or 450) is disposed as illustrated in Figure Proximal stent porcion 401 engages the inner walls of the aorta above tche-aneurysm. Distal stent portion 402 engages the inner wall of the aorta below the 999.
15 aneurysm. Intermediate fabric portion 403 excends across tche aneurysm, providing a strong, stable lumen for blood flow *9 *9 through the aorta.
Figure 28 illustrates the delivery apparatus used to implant straight stent 400 in the vasculacure. This apparacus *999 20 is very similar to that described above for the delivery system to be used with the bifurcated stent or prosthesis.
Accordingly, like reference numerals refer to the same
S..
components.
In the introducer 410 shown in Figure 28, proximal 25 portion pusher 102 engages proximal stent portion 401. Distal oportion pusher 103 engages distal stent portion 402.
In use, straight stent 400 is first charged into the introducer by cooling it to temperatures below 101C, radially compressing it, and inserting it within outer sheath 101, as described above in co nection with the blurcazed ste'n or prosthesis. The remainder of incrnducer ;tI is als. asserrmbled as described in connection with incroduc iOo0.
Introducer 410 is passed chzou;j an entry point (not shown) over guide wire as sho -n i Ficcure 2' This insertcion may be acccmoIlished us ing percuaneous or cut-do wn 32 tecni2cues. _Introducer 410 is Chen iserced Cc th-'e desired deliver-y location.
in the aorta, introducer 410 is oositioned and balloon 107 is in.flated above the renal arteries in the same manner as described above in connection with the bifurcated stent and as illustrated in IFig. 24(Ca) While maintaining proximal oorcion pusher !02 in a fixed-osictlon, outer sneath 101 is withdrawn until oroximal portion 401 Of stent 400 emerges from outer sheath !01 as shown i4n .7ig. 24(b). Using a radiooacue marker- 420 disoosed on the proximal end of the orox-imal oorcion 401!, srtent 400 is ooC imal ly/ aligned with'Lin the aorta. Outer sheath 101 is further withdrawn until' oroximal oortion40 emerges *therefrom, as shown in Eigure 25. Outer sheath 101 is Cnen further withdrawn until it is El-ush with oroximal ;3-,7rion pusher 102. Then both outer sheath 101 and oroximal portion ousher 102 are withdrawn while maincaining distal portion ousher 103 in a fixed position. Distal portion 402 is thus deployed from Che end of outer sheath 101, as shown in Figure 20 26.
Balloon 107 Is then deflated and withdrawn inside proximal portion 401 where balloon 107 is re-inflated to seat the scent 400, as show-. in Eigure 27. Balloon 107 is then withdrawn, along with the introducer 410 as described above.
and the entry point is closed.
~'ig.29 illustrates the apparatus used to deploy straight stent 450, show-n in Figure 23, olf the oresentinvention. This apparatus is very similar to that described above Eor the deliver'/ system to be used wit-h the bifurcated scent or prosthesis. Acccrdi;nglv, likze reference numerals refer toth sair: comocnencs.
2~oiml orti-on oushQL- 102 Chis embDodirient is glued to distal; oortioll Ousher- 103 suchn cthat enids 11-5 and 116 are Elush. ThIese, L"Lush ends are adapted Cc engage sternt 4150 within ouzerI shieath 101.
33 In use, straight stent 450 is firs: charged into introducer 490 by cooling it to temperatures below radially compressing it, and inserting it wichin outer sheath 101, as described above in connection with the bifurcated scent or prosthesis. The remainder of introducer 490 is also assembled as described in connection with introducer 100.
Incroducer 490 is passed through an entry point (noc showni over a guide wire 411 as shown in Ficure 30. This insertion may be accomplished using percutaneous or cut-down techniques. Introducer 490 is then inserted to the desired delivery location.
In the aorta, introducer 490 is positioned and balloon 107 is inflated above the renal arteries in the same S" manner as described above in connection with the bifurcated scent and as illuscrated in Fig. 31.
While maintaining attached proximal portion pusher 102 and discal porcion pusher 103 in a fixed oosition, outer sheath 101 is withdrawn until proximal portion 451'of stent 450 emerges from outer sheath 101 as shown in Fig. 32. Using 20 a radiooacue marker 420 disoosed on the oroximal end of the proximal portion 451, stent 450 is optimally aligned within the aorta. Outer sheath 101 is then completely wichdrawn until stent 450 is deployed into the aorta as shown in Fig.
33.
25 Balloon 107 is chen deflated and withdrawn inside proximal portion 451 where balloon 107 is re-inflated to seat the stent 450, as shown in Figure 34. Balloon 107 is then withdrawn, along with the introducer 490 as described above, and the entry point is closed.
J3 The angeoLogicaL disease o£ occlusion is che blockage of an artery resulting prom a bu.'.dup or cloc of sofc thronbus. There are -co tvoes of occlusions chat can occur at the aorca-iliac bicurcacion. The Cirst is :i.frarenal occlusion. In this case, the blockace extends in the aorta from just below the renal arteries into the iliac arteries.
3 ncsecond c:'roe is an occlusion cnac is li :ed co r:ne immediate area ot the bi furcation.
To treat an infrarenal occlusion, a canalization is Lfirst made through the thron'bus by methods known in- the arc.
e. bifLurcated endolurninal orosthesis accordi4n= to cthe- oresent inveation i.s then irnolanced at the bifurcaCion s52te to orovide an unobstrucced lumen excending fraDm che aorta -inco each of the iliac arceries. Blood can thus fiow freely f rom- the aorta to the iliac arteries.
The bifurcated end--olumin-al porosthesis accordinc to the present invention that is used to treat an occlusion must be fabric cover-ed. This is necessary co prevent emboliza, ion from the t'nroambus remain~na on the wall off the recanalized artery.
A~n occlusion at the oi~urcacion is created by *recanalizing the arter-y as above. A1 bifEurcated endoluminal :orosthesis according to the -present. inv-,ent ion may be implanted' at the bifurcation. Because the occlusion is limited to the ~immediate bifurcation site, hoeeteoroximal portion ofL 20 the proschesis may be shorter than that discussed above.
To imolant the bifurcated endoluminal proscnesis Co .creat, both types of occlusion, the deliv.-,ery system comprising introducer 100 discussed above for- deliverina the bifurcated endoluminal orosthesis to treat an abdoniinal aortic an-urysm 25 is used. The same delivery method discussed a.bovze for implanting the bifurcated endoluminal prosthesis to treat abdominal aortic aneur-/sms is used C-o implant the device to zreat the occlusion.
Using the method and anoaratus oLf this invention to Lreat- occlusion i.:ovidps an unobstr-ucceld lum',2, throug'h 'hich blood c~n flow from the aorza to the ;li;ac arte:rt.s.
The anceologicaL disease of s-enosis is a :ar.~l off an acrerv caused by a buiLduo off hard caLcifiled olianu:2 'S su'sualLy/ ca.usccd a bul~~o ls~ ol. -0 r~2 such an angeological disease, angiJoolastv, is oerformed on, the olaoue accorcl-ng Lo method's ell hn.n c the art. T-Ie bifurcated endoluminal stent according to the present invention is then implanted at the bifurcation site. This stent is the same as that described above for treatment of an abdominal aortic aneurysm. To treat the stenosis, however, it is not necessary to cover the stent with a fabric, thus creating a prosthesis.
Because restenosis is rare at the bifurcation site, there is no need to isolate the blood flowing in the lumen from the walls of the arteries.
The delivery system used to implant the bifurcated endoluminal stent used to treat stenosis is the same as that illustrated in Figure 8 except that balloon 107 is not required. Because there is no fabric around the stent to be affected by blood flow in the arteries and cause migration of the bifurcated stent, it is not necessary to block to blood flow with the balloon. Otherwise, the delivery system for implanting the bifurcated stent to treat stenosis is the same as that for implanting the bifurcated prosthesis to treat abdominal aortic aneurysm.
S 15 Similarly, with the exception of the steps involving inflation of balloon 107 block the blood flow, the method of delivering the bifurcated endoluminal stent to treat stenosis is the same as that described above for delivering the bifurcated endoluminal prosthesis to treat abdominal aortic aneurysm.
"Comprises/comprising" when used in the specification is taken to specify 9 20 the presence of stated features, integers, steps or components and does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims (8)

1. An introducer for delivering, into the vasculature at an angeological bifurcation where a blood vessel branches into two branched vessels, a bifurcated endoluminal stent or prosthesis having a proximal portion adapted to be disposed in said blood vessel and a distal portion adapted to be disposed at least partially in one of said two branched vessels, said introducer including: a tubular outer sheath; a proximal portion pusher slideably disposed at least partially within said outer sheath and adapted to engage a distal end of said proximal portion; and a distal portion pusher slideably disposed at least partially within said proximal portion pusher and adapted to engage a distal end of said distal portion.
2. An introducer as claimed in claim 1 further including a balloon catheter, having a balloon attached thereto, said balloon catheter being disposed at least partially within said distal portion.
3. An introducer as claimed in claim 2 further including a hemostasis valve attached to the distal end of said distal portion pusher.
4. An introducer as claimed in claim 2 further including wings on said outer sheath and said proximal portion pusher.
5. An introducer as claimed in claim 2 wherein said balloon catheter has an injection orifice and an injection conduit therein.
6. An introducer as claimed in claim 2 wherein said balloon catheter has an inflation orifice and an inflation conduit therein.
7. An introducer as claimed in claim 2 wherein said balloon catheter has a ro xi, Mal end with a nose cone attached thereto.
8. A method for delivering a bifurcated endoluminal stent or prosthesis having a proximal portion and a distal portion into the vasculature at an angeological bifurcation where a blood vessel branches into branched vessels, said method including the steps of: inserting an introducer containing said stent or prosthesis into the vasculature to a predetermined delivery location, said introducer including an outer sheath, a proximal portion pusher, and a distal portion pusher; withdrawing said outer sheath of said introducer while maintaining said proximal portion pusher in a fixed position until said proximal portion of said stent or prosthesis is deployed from said introducer into said blood vessel; withdrawing said outer sheath and said proximal portion pusher while maintaining said distal portion pusher in a fixed position until said distal portion of said stent or prosthesis is deployed from said introducer at least partially into one of said branched vessels; and withdrawing said introducer from the vasculature. DATED this 5 th day of February 2003 BOSTON SCIENTIFIC TECHNOLOGY INC WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA P2705AU04 RLT/DHS/PCP *o *ego
AU53401/00A 1994-02-09 2000-08-16 Bifurcated endoluminal prosthesis Ceased AU759269B2 (en)

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AU53401/00A AU759269B2 (en) 1994-02-09 2000-08-16 Bifurcated endoluminal prosthesis
AU29352/02A AU776868B2 (en) 1994-02-09 2002-03-28 Bifurcated endoluminal prosthesis
AU29353/02A AU776872B2 (en) 1994-02-09 2002-03-28 Bifurcated endoluminal prosthesis

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EP94400284 1994-02-09
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US312881 1994-09-27
US317763 1994-10-04
AU32245/99A AU725720B2 (en) 1994-02-09 1999-05-26 Bifurcated endoluminal prosthesis
AU53401/00A AU759269B2 (en) 1994-02-09 2000-08-16 Bifurcated endoluminal prosthesis

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989008433A1 (en) * 1988-03-09 1989-09-21 Lazarus Harrison M Artificial graft and implantation method
EP0508473A2 (en) * 1991-04-11 1992-10-14 Endovascular Technologies, Inc. Endovascular graft having bifurcation and apparatus and method for deploying the same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989008433A1 (en) * 1988-03-09 1989-09-21 Lazarus Harrison M Artificial graft and implantation method
EP0508473A2 (en) * 1991-04-11 1992-10-14 Endovascular Technologies, Inc. Endovascular graft having bifurcation and apparatus and method for deploying the same

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