CA2007562A1

CA2007562A1 - Reinforced graft assembly

Info

Publication number: CA2007562A1
Application number: CA002007562A
Authority: CA
Inventors: Norman R. Weldon; David C. Macgregor
Original assignee: Norman R. Weldon; David C. Macgregor; Corvita Corporation
Current assignee: Corvita Corp
Priority date: 1989-07-10
Filing date: 1990-01-11
Publication date: 1991-01-10
Also published as: EP0407692A1; JP2739878B2; JPH0345251A; US5084065A

Abstract

REINFORCED GRAFT ASSEMBLY
Abstract of the Disclosure A reinforced graft assembly made from a vascular graft component and a reinforcing sleeve component. The reinforcing sleeve component may include one or more layers. The diameter of the inner surface of the most internal layer of the reinforcing sleeve component is approximately equal to or larger than the diameter of the vascular graft component thereby allowing the former to be fitted over the latter. The compliance of the sleeve component is adjustable depending on the application needs, for example, by varying the angle at which the fibers used to form the sleeve component are laid down and by the method used to join the two components.

Description

~-- z~
:` 756Z

PATENT ::
Case 880705 IR 88037 ~ .
REINFORCED GRAPT ASSEMBLY
5De~cri~tion ~ `
' .
Backqround and DescriPtaon of the Inventlon :: ~
The present invention genera}ly relates to : . :
a graft. More particul~rly, the invention rela~es to a graft, Cuch as a vascular graft, constructed fro~
two componentss a synthetic, blologic or biosynthetic vascular graft component and a reinforclng sleeve component, each of which h~s ~n appropriately aized intern~l diameter ~o the graft 15 component may be fitted ~ithin the sleeve co~ponent. ¦, In the medical treatment of patien~s with diseased arteries or veins, surgeons mzy replace the failing ti88ue ~ith prosthetic conduits ~uch as ~ascular grafts. Conventional grafts~ h~ever, can : ~
20 kink or collapse mechanlcally und~r a variety of ~ -circumsta~ce~ such as ~ben the graft i~ b~nt during the contr~ction oS the surrounding ~uscle, or ~ben e~ternal pressure i~ applied to the gra~t durlng a period of rest taken by the reclpient o~ the gr~ft.
25 One conventional solution to the~e proble~s has con~iste~ o~ the reinforceMent of the ~ o væscular gr~f t8 by the ~eak attachmen~ of eith~r ! `:
di~crete poly~eric ring~ or contlnuo~s spir~
poly~eric band~ to ~ portion~ albeit often a sDall ~:
30 portio~, of the e~terior su~ce o tb~ pro~the~is. I. ;
Gr~t~ to ~bich ~uch li~ited r~n~orcing :~
rlng~ or b~nd~ ar~ attaeh~d have cert~in li~ tlo~s.
0~ it~tio~ of oon~ntio~ally r~in~orccd va~icul~
gr~ft~ i~ t~at th~ r~ or¢lng ~e~b~r ~ay lntorfl~r~ i .;
35 ~ith tbc cre~tion o~ ~n ~ to~o~i~. In 8UC~ ai~e~ `:
tb~ reinor~æ~ot ~u~ b~ ~y~ lly r~s~d by ~00756z ~;~

peeling or cutting t off the graft at the time of surgery. Another li~itation is that, becau~e the reinforcement i8 confined to certain areas of the graft, the reinf orcement may not necessarily coincide with the area where the reinforce~ent protection i~
~ctually needed. Thi~ may happen where the ~o~t desirable site to create the pro~imal and di~tal anastomosis i8 in an area of ~he patient which anatomically presents dif~iculties to the placement of the reinforced graft. An additional limitation iY
that the stiffness of the reinforcing ~ember may reduce the ci rcumf erential and/or longitudinal co~pliance of the graft. A non-compliant gr~ft ~ill ~educe the pulsatile flow through the graft tbereby co~p~omi~ing the ability o the prosthesis to perfor~
naturally. Pourth, the rein~orcing ~e~bers of conventional vascular graf ~8 bave a smooth and non-porous surface. Such a aurface cannot be penetrated by cellular growth and, accordingly, represents a biologically i~co~patible interface between the graft and the ho~t tisaue. This inco~patibility may cau~e the ero~ion oS the ~u~rounding ti~sue, the or~tion o~ undesirable burs~e ~nd fibrotic capsule~, or the for~ation of calcium deposits.
~ he present invention includes a ~o-co~ponent syste~, one co~ponent of ~hich, the graft componen'c, co~-prise~ a ~ynthetic, biologic or biosynthetic graft, including the type detailed in D.S. Patent ~o. ~,355,~26 ~o ~aoGregor and, i~ pnrt, in V.8. P~ltent llo. 4,7~3,252 to ~artin and ~aGregor and f~bric~ted i~ the ~anne~ detailed i~ ~.S. Patent No. 4,~7S,972 to ~ong. Theae pnt~nts are in¢o~porated ~y ~efer~nce h~ to. Th~ oth~
oo~po~e~, tho sle~ c0~2~t ~y ba ~o~e~ r~
~ynth~tl¢, blologic~ or blo~y~th~t~ ~at~lal. Sh~

Z!)07562 - ~

:
,`

graft component comprises a porous kurface and a network of interconnected interstitial pores below the surface, which network is in fluid flow communication with the surface pore~.
The second component of the two-component system of the present invention includes a reinforcing sleeve com~onent. Like the graft component, ~he ~econd component includes a porous surf~ce and a porous sub~urface. The ~leeve component has an inter~al diameter ~hat i8 egual to or larger th~n the external diameter of the graft co~ponent and, as Cuch i~ ~ized 80 that it may be fitted over the fir~t component of the present inventlon.
The two-component system of the present invention provide~ advantageously a syste~ which, while prov$ding reinforcement to a graft, overcomes the lL~itation~ as~ociated with conventional graft ;~
reinfo~ce~nt ~ystems. Por e~a~ple, by separating the graft co~ponent fro~ the reinforcing sleeYe co~ponent, the blood transporting function handled by the former i8 isolated from the ~echanic~l load bearing function handled by the l~tte~. ThiB
i~olation act~ to preserve the inherent co~pliance of the blood tr~nsporting member. A non-conpl~ant blood transporting ~ember wlll inter~ese with nnd break up ~
the natural wave flow of in vi~o blood, which i8 a ;;
seriou~ di3adv~nt~ge of prior art reinforced grafts.
Generally ~po~k~ng, prior art reinorced vascular grafts ca~ reduce the pulsatile ~lo~ o blood there~hrough by A factor of 80~e 10 to 30 p~rcent. . ~
~h~ t~o-co~ponent ~yste~ of the present ;-in~ntlon al~o ~ W8 the ~eparAte reinforcing ~lee~e co~ponent to b~ l~c~e~ at i~y positio~ ~long t~e length of th~ pro~L~si- or essn ~cro~ ia~
~na~to o-i- th~r~by pro~ldl~g ~upp~rt to ~ loc~liæed .

;~00756;~ ;`

.
section of the graft or host artery. For e~a~ple, during the course of surgery~ the ~lidable i reinforcing sleeve according to this invention can be j precisely located to provide needed reinforcement at Z~ 5 a precise loc~tion, such as acros~ a knee joint, a rib cage or the like.
A two-component ~y~tem, as in the present invention, in which the graft component i8 rein~orced by a sleeve compon~nt, also may be fitted into a 10 restricted area without reguiring the removal of the seg~ented reinforcing rings or band~ taught in conventional reinforced vascular grafts.
Additionally, because the reinforcing ~leeve cooponent may be fi~ed over the graft co~ponent ..
15 through a ~ariety of mean~, and the oeans choaen to accomplish the fixation affects to a certain degree 1 the co~pli~nce, the resultant compliance of the ;Z reinforced graft asse~bly i5 adju~table. In J addition, cODpliance i8 adjustable by winding the .~ 20 fiber~ of the reinforcing sleeve compohent at an ~'Z angle ~hich enhances kink re~i~tance. Co-lpliance i8 I also adjust~ble by vary$ng the duro~eter hardnes~ of the fibers fro~ which the reinforclng sleeve ! col~ponent i~ ~-ade.
The structure of the present invention aids ; in renderlng the invention bioco~patible ~nd hemocompatible and f~cilit~ites its fi~tion uithin :~ the body. The ~or~er adv~ntage is reali2ed due to ~.
the porou0 sllr~Eace ~nd sub~urface net~ork 30 chl~racterising tbe structure of the invention. Thl8 .-i, structure encour~ges cellulglr ingrowth ~n~ OW8 a ootb, tb$n ti~ue co~ting to forD~ and to ~dhere to ~-1 tbe porou~ surf~ce of tbe present inrention.
De~irably, this coating r~ r~ the gragt r~ ~Z~t ,~i 35 to tb~ or-at~,on of blood clo~ ich sr~ allr ;1 ~s~ociat~d ~ the pr~aanc~ og forelgn bodi , l~uch ,, ,~ Z.')~7562 . ~

:
a~ graf ts or prosthese~ the blood stream. The : .
latter Phenomenon, that i8, the fiYation of the strengthened graft to ~he adjacent l:issuec~ i~ cau ed also by the for~ation of the adherent ti88ue coating on the porous surf ace. It allow~ the i~plant to be incorporated into the cardiovascular 8y8tem thereby achieving a more secure attachment than previou~ly ; .
obtainable. ! ~ - ~
It i6, accordingly, a general object of the present invention to provide an i~proved graft.
Another object of tb~ present invention i8 ~ `
to provide an improved gr~ft ~sQembly havinq a compliant inner graft component and a reinforcing sleeve component that does not substantially 15 interfere with the compliant properties of the inner :
graft co3ponent. ~:
Additionally, it i~ an object of this ::~
inven~ion to provide an i~pro~ed reinforced qraft who6e overall compliance i8 ~djustable.
~nother object o this invention i8 to provid~ an i~proved reinforced graft and ~ethod of makîng sa~e.
The~e and othe~ object~, features and , : *
advantages o~ this invention ~ill be clearly understood th~ough a consideration o~ the followin~
detailed description. ~:
Brief Descri~tion of the Dra~inq~
I~ the course of this deacriptio~, :::
referenc~ will be ~ade to the ~ttached dra~ings, :~
30 ~here~n: 3 ~;
Figure 1 i~ n pe~sp~cti~e vie~, partially I ~::
broken a~2y, of a kno~n graft co~p~nent æuitable or incluBion in the as~el~bly a~:cordlng to tho pre~c~
inventiont ~igur~ 2 iæ ~ p2r~pecti~e ~ , part~lly cut a~Ay~ o one e~b~a~-ent o ~ r~ orei~g ~l~ev~ ~
., .
: ~, .~ z~75~z component according to this in~ention into which the graft component illustrated in ~igure 1 ~ay be fitted;
Figure 3 is a perspective view, partially broken away, of another embodiment of a reinforcing sleeve component accordi~g to this invention into which the graft component illu~trated in Figure 1 ~ay be fitted;
Figure ~ i~ a cut away peespective view illustrating a cross-section of the reinforcing sleeve component shown in ~igure 2 in which the component i~ protected from biodegration by spinning the fiber~ which ~orm the internal layer and the external layer beyond the lntermediate layer ribbon or ~ilament;
Figure 5 i8 a cut away perspective view similar to Figure ~ and in whic~ biodegrad~tion prevention o the reinforcing slee~e componen~ i~
further enhanced by applying a ~oft polymer to the ends of the polymeric ribbon or filament of the inter~ediate layer of the 2~bodi~ent illustrated in Figure 25 and Figure 6 i8 a cut aw~y perspective vi~w which illustrates another e~bodi~ent ~or preYenting biodegradation of the reinforcing ~leeve co~poncnt.of the e~bodiment illustrated in Figure 2 by ~nicuring i.
the ends of the poly~eric ribbon or ~ilament of the inter~diate l~yer.
D~cription_of tbe PaEt~CU1~r ~bodi~ents ~ 30 The presen~ en~ion typically i3 a : two-co~ponent ~se~bly of ~ synthetic~ biolcgic or bio~ynth~t~c gr~t ~o~po~en~ c~ generally ~no~n type togeth~r ~1 ~ n~ e~t~rnal r~in~orcing ~l~eve co~pon~nt~ Tbe g~ag~ illu~tr~t~ i~ the dr~ng~ i8 3 5 a Ya~ql~r graft co pon~nt.

2007~

The pre~erred qraf t component i~
illustrated in Figure 1 and is generally designated by reference numeral 11. Graft component 11 has a porous surface 12 and a network 13 of interconnec ed interstitial pores below the surface which are in fluid flow com~unication with the ~urf~ce 12. ~hen the device i~ i~planted, the porous surface 12 and the ~ubsurf~ce network 13 promote cellular ingrowth and the formation of a s~ooth, thin, adherent tis~ue coating, not shovn, on th~ porous surface 12. This coating renders the graft component 11 bioco~patlble and he~oco~patible and specifically ~11OWB the surfDce 12 to remain resistant to the for~ation of blood clot8 ~nd the like normally as~ociated with the presence of foreign bodies, such as grafts or prostbeses~ in the blood stream~ Additionally, the coating facilitates a ~ecore attach~ent of the graft :~ -into ~be cardiovascular ~yste~
The methods by ~hich the graft component 11 may be fabricated include those disclosed i~
Pate~t ~o. ~,~75,972. In one fabrication method disclosed in ~.S. Patent ~o. ~,~75,972, and termed BolUtion processing~, a biocomp2tible polymeric ~ater1al, such ~8 biocompatible polyureth~ne, i8 dissolved in a suitabl~ solvent, such as diDethyl for~a~ide, to form a v:Lscous sQlution. The resultant ~wet~ solution i~ puJped under pressure into a ; didtributor and out tb~ouq~ one or ~ore orifices to for~ one or ~ore continuous fi}a~en~ of tubular :-~ate~i~l. ffl e e~truded fi~er or ibor~ are placed in cont~c~ ~ith ~ rot~ting ~andr~l. Because the eyt~rior d~ai~tes ~iYe of the ~ndr~l ~ill deter~ine the inn~ dl~et~r 31s~ of tbe gra~ ~o~po~ot 11, ~ : .
g~gt o al~o~t a~y l~tarnal dia e~ nay be o~de by choo~lng a ~a~dr&~ of ~h~ approp~l~t4 ~
Th~ trlbutor or spln~r~tt~ reelproc~te~ fro~ O~Q
", ; .

"- Z(~075~Z

axial end of ~he mandrel to the other 90 that the fibers are wound onto the mandrel in different and OppO 8i te direction~.
The conditions of the winding proceP6 are S critical for purposes of opti~i~ing t:hose characteristics which directly affect the p*rformance of the graft component 11. On~ such ~haracteristic i8 the compliance of the graft component 11. This characteristic may be varied by selecting the appropriate diameter of the fiber ~ro~ which the graft oomponent 11 i8 for~ed. The circumferential speed of the rotating mandrel will deter~ine to what degree the fiber extruded in contact with the m,~ndrel will stretch. The greater the stretch, the s~aller the diamete~ of the ~iber and the greater the fle~ibllity and compliance of the resultant graft.
Compliance may also be varied according to the angle at which the f iber used to for~ the graft component ~ ~ .
11 i8 wound. Radial compliance varieR on an inverse proportional basis to the angle of winding, with a les co~pli~nt ~raft made by increasiAg the angle of winding, defined as an acute angle ~ith r~pect to the a~is of the graft or oandrel on which it iA
wound.
~Xink re~i3tance~, that iR, the ability of the graft to be bent without gre~tly reducing the croso-~ectional area of the inside of the gr~ft, i8 anotber chnr~cteristlc which D~y be varied by t~e angle at ~blch the fibær for~ing the gr~t co~ponent 30 11 iff ~ound. ~ graft ~ltb little ~kink re~istanc~
will ~ink with only llttle bending o~ the grat thereby stopping the flo~ o~ blood. Tbe larger the ~nql~ of ~lndi~g~ the gre~te~ the abllity of the gr~t to ~ith~nd fle~ing ~i~bout ~lnki~g, a~d the 35 ~ore u~ful t~ gr~ft 18 for applic~tion i~ losatlons ~hl~h ~y b~ sub~ct~d to ~uch fle~l~g.

~ - ~o :

-9- ~;

The poroQity and the shape of the pore~ of ~
th~ graft dependq al80 on the angle at which the ;:
fiber i8 wound onto the mar~drel. Specifically, a -~
smaller angle of ~inding will produce a ~maller pore 5 size and reduced porosity. The ~pinnerette i~
allowed to reciprocate with re~pect to the ~andrel .,.~.;~;.
until the desired thickne~s of overlayed f ilament~ i8 obtained. When desired, the ~ilaments ~8y be extruded f rom the mandrel ~wet, and upon ev~poration of the solvent, the fila~ent~ Gecurely bond to each other at the point of overlap. A stable and non-woven structure result~ without the need for ~dditlonal proces~$ng.
While spinnable polyurethane materials are -preferred, the graft may al80 be made from other polymeric materials, such as polyolefin~ including polyethylene. With zuch polyl-eric materials, the .:
spinnerette ~ay be heated to produce tacky, fusible, and substantially solven~-free f ibers which bond to ~ :
20 each otber on the mandrel as the fiber~ cool.
Alternatively, the ~andrel ~ay be heated to use :' fibers ~18 they are laid on ~ach other ~
The reinforcing sleeve co~ponent according :
to the present invention 1~ illustrated in Piqure 2 through Figure 6. Thi~ co~ponent includes one or more layers which for~ a sleeve that i~ suitable for ~.
fitting over the graft co~ponent of th~ graft ~ :
asse~bly accord~ng to the invention.
One e~bodi~nt of t~e rei~foro$ng sleeve co~ponent according to the pre~ent inv~ntio~, ~, de~ignated 20 ~n Pig~re 2, include~ three layer~s i flrst or ~t2rna1 l~yer 21~ ~ se~ond or lntes~ed~ate l~yer 31S ~d ~ third cr ~ter~l layer ~ e in1:ern~ y-r 21 any b~ f orDed f ro~ ~y~bet~, 35 blologl~, or bioq?~thetlc and ge~rally bio~o~patl~
~at~ri~ ~<:cord~ng ~o ~h~ ~thod taught in , ~ ........... . .
. .

~ Z~)0756i~

-10- ~
:
Patent No. 4,475,972 (as generally described above) and from fibers 24 which ~ay ~ange f,rom about 1 micron to about 100 ~icrons and preferrably from S to ~ :
30 microns in diameter. ~he resultant internal layer 21 has an inner cylindrical surface ;22 who~e diameter is equal to or greater than the esterior dia~eter of the mandrel, not shown, on which the internal layer 21 i8 formed.
Onto the outer cylindrical sur~ace 23 of the internal layer 21, nn inter~ediate layer 31 may be wound. ~he inter~ediate layer ~ay be for~ed fro~
fibers of a biocompatible material according to the method taught in U.S. P~tent ~o. ~,475,972.
Preerably, the fibers are in the ~hape of a ribbon or f ilament 3~ which i8 generally flat or rect~ngular in cro~s ~ection, thereby enhancing the ~tiffness of the eleeve component 20. The fibers of thi~
intermediate layer 21 could be generally circular, depending upon the particular stiffne 8 propertie~ :
th~t are needed for the 61eeve co~ponent 20. ~he ribbon or fila~ent 3~ ound at an angle r~nging fro~ 35 to 85 w~th re~pect to th~ com~o~
longitudinAl ~ of the reinforced vascular gr~ft 20 and ~ay h~ve a dia~ter ~bicb ~y range i~ si~e fro 300 to 3,000 microns and preferably 500 to 1,000 microns .
An e~ternal layer ~1 ~ay be fabricated and laid over the out2r AUrf -CO 33 0~ tbe inter~ediate laye~ 31 according ~o tbe ~ethod~ disclo~ed in ~.S, 30 Pd~. ~o. ~,~75,972 aad as d~scu3sed ~bove.
Biocoapatible ~aterial in th~ gor~ of f~ber~
~$cron to 100 ~icro~s ~d pref~r~bly 5 to 30 ~icro~
in dia~e~er ~ay bo u~d to ~a~ the e~te~al layer ~:

4~.
, r' )7562 :-~
: ':'' "

--11-- ;,,... .:` .
~.... ...

In order to enh~nce its resi tance to biodegradation, the reinforcing ~leeve component 20 ~:
may ~e given an atraumatic ~hape. With reference to .:
Figures 4 through 6, this m~y be accompli~hed by, for e~a~ple, spinning a plurality of the fiber~ 44 which forD esternal layer 41 and a plurality of the fibers ~
24 vhich form internal layer 21 beyond the end~ 35 of ~.
the ribbon or ~ilament 34 fro~ Yhich intermedi~te layer 31 i~ for~ed, thereby encapsulating or covering ` .
10 the ends of the inter~ediate layer 31 to for~ a : :
surface ~4a. Pibers 2~ and fib~rs 44, which form internal layer 21 ~nd for~ estesnal layer ~
respectively and are spun beyond the ends of the inter~ediate layer 31, ~y be heated, as with the 15 entire co~ponent 20 to form a surface ~4a which is : :
~ooth. Alternatively or additionally, the :
reinforcing slee~e component 20 may be rendered : :
atrau~atic by applying a bead 3~b of a soft poly~er, `~
such as silicone rubber, to the ends of the f ibers , :
20 exposed at the periphery, or by pro~idlng the ~einorcing sleeve co~ponent 20 with a n~nic~red ead 4S sucb a~ by flarinq, tailoring, 801~ent ~anicuring and the like. Generally, ~hen these types of :~ .
treata~nt~ ar~ carried oUt on the reinforcing sleev~ . ;
component 20 they ~re ~08t advantageously c~rried out on tho ~ib~rs 3~ ~hich for~ the inter~ediate poly-eric Eibbon or fila~ent layer 31 Another embodl~ent o~ tbe relnforcing ~leeve co~ponent ~ccording to the pre~nt in~ention 30 include~ a slngle l~y~r designated 50 in ~igu~e 3. .
~he layer 50 -y be fabric~ted by ~ ~uitable ~ethod sucb ~ ~h~t dl~closed ln V.~. Patent ~o. ~75,972 by ~ln~lng fiber~ 34A, au~h ~i~ thoe0 ~ r~ a b~ooo~tlbl~ ~t~rl~l a~ ~bout 1 ~icro~ ~o ~bout 100 ~ oi~J i~ dla ~ter, onto a totatl~ ndrel ~t an a~qi~ ~ltbl~ th~ rai~g~ of about 75 ~ 10~

-2~1 )75~;~

respect to the common longitudinal axis of the mandrel. A generally noncompliant ,and very kink resistant tubular structure result~. ~pon completion of the winding, the reinforcing sle~eve component 31a 5 thus formed may be protected from biodegradation by suitable procedure~ or treatment~. j A further embodiment of the reinforcing sleeve co~p~n~nt according to the present invention :
i~ illustr~ted by the layer 50 in Figure 3. In this embodi~ent, the layer S0 ~ay be fabricat~d by a suitable method such a~ that diwlos~d in ~.S. Patent No. 4,~75,972, from flbe~ 34a which are ~ade from a biocompatible material havinq a relatively high durometer hardne8~ that i8 g~eater than that of the fibers out of which graft component 31 is constructed. For e~ample, graft co~ponent 31 can be made fro~ Pellethane 80A polyurethane fibers, while the fibers 34a ~ould be made of a harder ~terial such as Pellethane 75D or Pelleth~ne 55D polyurethane 20 3~teri~1180 Fiber~ 348 typically range f ro~ about 1 ~icron to ~out 100 Dicrons in dia~eter ~nd are wound onto a ~andrel at an angle ~ithin the range of about 65~20 with reape~t to the longitudinal ~ of the .
25 ~4ndrel. A relatively non-co~pliant, but ve~y .
kink-resi~tant, tubul~r str~cture result~. Upon .
co~pletion o~ the ~inding, the reinforcing ~lee~e .
co~ponent 31a thu~ for~ed ~y be p~otected fro~
biodegr~tlon by ~ult~ble treatments or othe~
., 30 prvcedur~s.
A re~nforced v~scular grDf~ according to the pr~sent invention a~y be for~ed by plncing, such al ~ing, ~ny o~ o~ th~ ~æbod~ents o~ th~
re~nfor~g ~lo ~ ~ ~o~pone~ oY~r th~ gr~t co~ponent 11 to thor~by ~or~ tb~ re~nfo~c~d gra~t a~e3bly.
~h~ ~Y~r~ oDpll~ of th~ rei~orc~ gr~ft Day b~

.

~ 07562 : ~
.: ., :.

controlled, to a certain degree, by the means used to join the two component~, which may be accompli~hed during a surgical procedure. Por e~ample, if graft component 11 i~ held within th~ reir~orcing sleeve co~ponent 20 or 50 by a friction fit:, a relatiYely lesser compliant reinforced graft a~6embly will result. A ~ore compliant rein~orced gra~t as~e~bly will re~ult if the graft coDponent 11 i~ loo~ely hl~ld within the reinforcing slee~e component 20 or 50 80` :~
th~t a spacing ~ay be provided between the two co~ponent~. Spacing would aid in the maintenance of the pulsatile flow through the assembly. The two cooponents of a more co~pliant reinforced graft asse~bly may be fixed through the application of any appropriate fi~ative ~eans, such as adhe~ives, for e~ample, cyDnoacrylate ce~ent, fibrin glue, etc., or mechanical ~eans, for e~n~ple, 8uture8, velcro 8trip8, etc. to one or bo~b ends of the two ~ --coDpon~rlts. ~ ~
Accordingly, th~ co-pliance of the ~;
reinforced graft aase~bly of the pre~ent inv~nt-on i~
ad~ust~ble in variou~ ~ays. One c~n control the angle ot whicb the fibess, th~t for~ eitber or both of tbe co~ponents, e~pecially the sle2ve, are ~ound.
Gener~lly, the gre~ter the ~inding angle wlth respect to the longitudinal a~s of the ~andrel, the le~s co~pliant the graft. One c~n u~e f~b~ra of differing h~rdness. One ¢an use u~ti~le layer~ to forn th~
reinforc~ng ~leeve co~ponent. Co~pli~nce of the rein~orced graft ~ e~bly is ~l~o controlled by select~ng the ~ana used to ~oin th~ t~o co~ponents of the ~sse b1y. ~or e~pl~O u~ing ~ fe~
~t~rrupted xutures ~o ~æcur~ ~he ~8~bly togeth~r ~ould ~lntaln eup*rlor aonpllAnc~. ~ddi~ion~lly, ~q p~71ding ~p~ g betwee~ th~ tvo co~pon~nt~t ~ ~or~
eoapll~nt ~8~Dbly re~ul tB.

.

;~t)0'7~
.

It will be understood that the embodiments of the present invention as described are illustrative of some o~ the applications of the principles of the present invention. Hodifications 5 may be made by those skilled in the art without departure from the spirit and 8COpe of the invention.

~ ~.

,! . ~ . i ~

't , . ..... '" .

!", ,.~ '. ' ., . . , '

Claims

1. A reinforced graft assembly, comprising:
(a) a compliant graft component, which is an elongated generally compliant blood transporting cylindrical synthetic, biologic or biosynthetic vascular graft having an outer diameter; and (b) a sleeve component, said sleeve component being a reinforcing sleeve capable of being fixed over said graft component, said sleeve including non-interwoven fibers made from a biocompatible material, said sleeve component having an interior surface with a diameter equal to or larger than said outer diameter of said graft component, whereby said sleeve component provides the primary load bearing function of the reinforced graft assembly, and said compliant graft component is isolated from said sleeve component and provides the blood transporting function of the reinforced graft assembly.

2. The reinforced graft assembly according to claim 1, wherein said fibers of said sleeve component have a diameter of between about 1 micron and about 100 microns.

3. The reinforced graft assembly according to claim 2, wherein said fibers of said sleeve component are wound onto a mandrel at an angle in the range of 65° to 85° to a longitudinal axis of said mandrel.

4. The reinforced graft assembly according to claim 2, wherein said fibers of said sleeve component are wound onto a mandrel at an angle in the range of 45° to 85° to a longitudinal axis of said mandrel.

5. The reinforced graft assembly according to claim 4, wherein said biocompatible material has a durometer reading greater than that of Pellethane 80A
polyurethane.

6. The reinforced graft assembly according to claim 3, wherein said sleeve component is fixed over said compliant graft component by means of adhesives.

7. The reinforced graft assembly according to claim 3, wherein said sleeve component is fixed over said compliant graft component by means of sutures.

8. The reinforced graft assembly according to claim 5, wherein said sleeve component is fixed over said compliant graft component by means of adhesives.

9. The reinforced graft assembly according to claim 5, wherein said sleeve component is fixed over said compliant graft component by means of sutures.

10. A reinforced graft assembly, comprising:

(a) a compliant graft component, said graft component having an inner surface and an outer surface, said graft component being made from synthethic, biologic, or biosynthetic materials;
and (b) a sleeve component, said sleeve component being made from synthetic, biologic, or biosynthetic materials, said sleeve component having an inner diameter suitably sized so the sleeve component may be fitted over the graft component, whereby said sleeve component provides complaint reinforcement to said graft component.

11. The reinforced graft assembly according to claim 10, wherein said sleeve component includes one or more layers which individually or as a group provide said reinforcement to said graft component.

12. The reinforced graft assembly according to claim 11, wherein said one or more layers includes an internal layer, an intermediate layer, and an external layer.

13. The reinforced graft assembly according to claim 12, wherein said internal layer includes fibers having a diameter in the range of 1 micron to 100 microns.

14. The reinforced graft assembly according to claim 12, wherein said intermediate layer includes fibers in the form of a ribbon or filament having a diameter in the range of 300 to 3,000 microns.

15. The reinforced graft assembly according to claim 12, wherein said external layer includes fibers having a diameter in the range of 1 micron to 10 microns.

16. The reinforced graft assembly according to claim 12, wherein said internal layer, intermediate layer, and external layer include fibers wound consecutively over a mandrel.

17. The reinforced graft assembly according to claim 16, wherein said intermediate layer is wound at an angle in the range of 35° to 85° to a longitudinal axis of said mandrel.

18. The reinforced graft assembly according to claim 13, wherein said fibers of said internal layer are made from polymeric material integrally bonded together.

19. The reinforced graft assembly according to claim 14, wherein said ribbon or filament of said intermediate layer is made from polymeric material integrally bonded together.

20. The reinforced graft assembly according to claim 15, wherein said fibers of said external layer are polymeric fibers which are integrally bonded together.

21. The reinforced graft assembly according to claim 12, wherein said intermediate layer includes a plurality of fibers spun longitudinally outward from edges of said intermediate layer to aid in protection of said intermediate layer from biodegradation.

22. The reinforced graft assembly according to claim 12, wherein said intermediate layer includes a soft polymer applied to ends of the fibers of said intermediate layer to aid in protection of said assembly from biodegradation.

23. The reinforced graft assembly according to claim 12, wherein said sleeve component includes manicured ends to aid in protection of said assembly from biodegradation.

24. A reinforced graft assembly particularly for cardiovascular use, said assembly comprising:
(a) a reinforcing component, said reinforcing component having a tubular structure of one or more layers of non-interwoven fibers of biocompatible material, said reinforcing component being capable of bearing a load imparted by or onto said assembly; and (b) a graft component, said graft component having a tubular structure made from synthetic, biologic, or biosynthetic materials, said graft component being suitable for transporting blood, said graft component sized so said reinforcing component may be fitted over said graft component to form said reinforced graft assembly.

25. A method of forming a compliant and reinforced graft assembly, which method comprises providing a reinforced sleeve component by a procedure including:
(a) winding extruded fibers made from biocompatible material onto a mandrel to form an internal layer of a reinforcing sleeve component;
(b) winding extruded fibers made from said biocompatible material and drawn in the shape of a ribbon or filament onto said internal layer to form an intermediate layer of said reinforcing sleeve component; and (c) winding extruded fibers made from said biocompatible material onto said intermediate layer to form an external layer of said reinforcing sleeve component; and (d) sliding aid reinforcing sleeve component thus formed over a compliant graft to provide said compliant and reinforced graft assembly.

26. A method of forming a compliant and reinforced graft assembly, which method comprises:
forming a reinforcing sleeve component by winding fibers made from biocompatible material into a tubular shape said winding being without weaving the fibers together; and sliding said reinforcing sleeve component thus formed over a compliant graft to form said compliant and reinforced graft assembly in which the compliance of said co pliant graft is substantially maintained.

27. The method according to claim 26, wherein said reinforcing sleeve component is further treated by imparting an atraumatic shape to longitudinal ends of said fibers thereof.