CA2096651A1

CA2096651A1 - Tension guide and dilator

Info

Publication number: CA2096651A1
Application number: CA002096651A
Authority: CA
Inventors: Robert S. Behl
Original assignee: Individual
Current assignee: Innerdyne Inc
Priority date: 1990-11-20
Filing date: 1991-11-12
Publication date: 1992-05-21
Also published as: JP3269556B2; US5312360A; DE69123982D1; DE69123982T2; EP0558642A4; EP0558642B1; WO1992008513A1; JPH06502791A; AU652979B2; US5275611A; AU9061591A; EP0558642A1

Abstract

A dilator assembly (10) for forming and enlarging percutaneous penetrations into body cavities includes an elongate guide member (20) and one or more elongate dilation members (30). The guide member includes a retractable anchor (22) near its distal end so that an outward force or tension may be maintained on the body cavity wall as successfully larger dilators are introduced over the guide member (20). In this way, the alignment of the guide member (20) is maintained along the initial penetration and the tendency for the wall of the body cavity to separate from and invaginate into the surrounding fascia is reduced. Alternatively, means may be provided for internally tensioning or stiffening the guide member so that the guide member will remain aligned and resist withdrawal, buckling, and kinking as a dilator or working catheter is introduced.

Description

2~ Pcr/us~l/08~35 T~STt:)N_I~DE AND DIL.~TOR

The present invention relates generally to aE~paratus and methods ~or providing percutaneous acc:ess into the interior of body cavities. More particularly, the pr~sent inYention relates to the construction and use o~ an apparatus for introducing on~ or more dilating lQ m~mbers to provide a relatively large penetration to the hollow body cavity.
The need to perc:utanec)usly penetrate a patient ' s skin in order to provide access into the interior of a hollow body organ arises under a variety of circumstances. For example, variou~; catheters, cannulas, and t}l~ like, may be introduced in order l:o aspirate the body cavity, i~troduce m~dication into the body ca~il:y, per:Eorm an interventional procedure withirl the body cavity, and th~3 }ike. Numerous devic:~s a~d m~thods have 29 been cleveloped in order to provide ~;uitable pene~rations for di~ferent procedures.
one colamc~n approach f c~r providing access to the :
interior o~ a body ca~ity utilizes a trocar and cannula as5ei~ y. Th~ trocar is a mQtal rod with a sharp tiE~, while th~ canmlla is a hollow tube which xec:eives the kroc:ar in i~s axial lual~n~ With the troc~r in place 50 that its. sharpened tip ~xterlds ~oxward of th~ car~llla, ~e a~se~ly can be introduced into the body cavity, typically throu~Th a sallall punchlrQ hol~. Th~ ~rocar is l:hen re~oved, and 1~h~ canmala r~ ins in place with i~s lum~n providing ~cc:ess to the interior o~ the body ca~,rii~y.
Slach ~rocar and ca nnula aqsemblie~ ~aY~ be~ll u~ed for ~any year~ and con~inu~ to be, ~d~q!aa~e ~or ~aray convent:Lonal pxocedtlres.. A major li~nita~orl eXi5~
how~rer~ ~ wh~n it is ~eæire2~ ~o in~roduc~ a relat:iv~ly large cathet~r or other ~ throuyh thQ punc~ure hol~

WO 92/OBS13 2119 6 ~ ~1 P~/US91/08435 surroundiFlg the cannula~ The initial purlctllre hole is kypically small and must he dilated o that larger devicas can be introducedO Dilatlon is typieally acc:omplished by successively introducing one or ~ore dilating rods having increasingly large diameters through t~e p~anctur~ hole and int,o the hollow organ, typicalIy over a flexible guide wir~ which haE; be~n introduced through the cannula, with the cannula then being remov~d.
Dilating rods typically have a tapered distal end in ord~r to facilitate their introduc:tion and a small central lum~n to receiv~ the guide wirQ. The USQ 0~ such conventioslal dilating rods is generaLly successful when . ~ entering cavities which ar~ relatively close ~o the skin and~or whic:h are restrained ~rom axial mov~men~ by their struc:ture or by attach~ent to surrolmding ~a: ;~ia .
The use o~ dilating rods is less success~iul with body organs which are not zxially c:onstrained, such a~3 the yall bladder, urinary bladder, stomach, and th2 like, and which have a tendency to move away froD~ anel x~sist. entry o~ ~v~n a hi~Thly tapered dilating rod. This problem is worsened 3:y th~ en~lenc:y of ~he flç~xibl~ guid~
wire to buc:kle or. bow slightly at the poin~ of en~ry and for the uncon~;txain~d dista:L o:E the guid~ wir~ ~o be pulled out of position withia~ ~he hollow bcady organ. The resulting misalign~ent o~ th~ ~id~ wir~ alld th~ ~ntry path for~ed by thQ guide wi:ce ca~n exa :::erbzlte the problem 9i~ dilating the pu~::ture. accP.~s by causinst bowinq and i~vaginS~tion of th~ struc:ture wall and t~aring of th~
body orgar1 a~ay from th~ ~urroundins3 ~ascia.. .

3 o Various teehrll~ues and dQYic:es hzlve been de~r~loped to at l~a~t pa~ly overc:o~ia these probl~m~;.
For exa~pla, dilat :ars haYing ve 3~all increm~ntal - inerea~3 in diaDlater co~bin~d with very gradually t~ 3red distal ends can reduce ~e incidQnce of fascial d6ltachm~nt. That approach; howevsr, i~ not alway~
suc~ s:eul and th~ n~ed to . @~ploy long~r, more ~ap~red dilatc: rs and/or a grea~r n~ober o~ dilators grea~ly :' .
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W092/08513 ~i~ 3 ~ 6 5 ~ Pcr/us91/0~3s increases dif~iculty o~ manipulating the dilators and/or the time necessary for perfoxming the procedure.
~n alternate a,pproach to preY~nt fascial detachment of the inter~al body organ has b~en the use of ~ultiple separate anchors or ~oggles which are placed peripherally about th~ s,ite of the primary puncture in order to more strongly aLttach the body org~n ~o its surrounding fascia. Suc:h an approach is generally workable~ but requires aL separate punctur~ for each anchor and subsequenk suturing o~ each anchor in place.
Again, such an approa~h incraases patient discomfort as well as the time n~cessary to per~or~ the procedure.
For these reasons, it would ~e desirable to provide improved methods an~ apparatus ~or forming and enlargi~g percutaneous pen~trations into hollow body organs and cavities. T~e apparatus and meth~ds should ~inimize addition~l ti~e and co~plexit~ requir~d ~or peæforming any as60ciated interventional procedure, and in particular ~hould a~oid the nead to make secondaxy perletrations in order to h~lp secUre th~3 body organ to t:he surrounding ~as~ia-. The ~thod~;- should b~ suitabl~
- ~ ~or introducirlg dilators o~ virtually any diameter, in ::ludang very }arge ~iamaters orl the ord~3r of 2 0 French 2~ French, and larg r wllile avoiding buckling and ~ ialignment o* the dilaltor guide me~r~ Moreover, th~
~nethQds and apparatu should be co~patible with virl:ually any typ~ o~ inter~en~ios~al.procedure which r~quixes th~
~orma~ion o~ a. percutaneous penE~ration for access ~o the - interior o~ a body cavity.
2. ~_ U.S. Patent No. 4~772,266, describPs a dilator~iheath as~e~ably t~a~ m~y he passed ov~r an in-:. ~d~elling guLde ~rir~ in ord~r ~o enlargQ an acc:e-~; hole, with entry of the shea1:h ~ur~Oer enlarging tl~ holeO
. U.S. P~lt~nt No. 1,21~,001, ~l~sc:ribe~ a ~roc:ar and ca~nula aE;~ Ly whi~:h include~a an int~ dia~e ~ube ~o form a ~re~-pi~ce st:~c~ure. U.S. Pa~nt No. 3,742,95B, WO 92/08513 ~ pcr/us91/o843s discloses a cannula having an axial ~;lot to allow th~
cannula to be stripped frc~m a working c:atheter which has been introduc::ed through the cannula. U. S . Patent Nos .

4,888,000; 4,865,593; 4,581,025; 3,545,443; and 1,248,492, each describe devices suitable for percutan~ous penetration oî a body ca~ ity, blood vessel, or solid tissue. The di~;c:losure~ of each c~f the U. S .
Patents cited ir~ thi~ paragraph are hereby incorporated herein by referenc:e. Hui~l:regtse, Endoscoplc Biliary and Pancreatic Drainage ~ pages 3-5, ( 1988 ) describe~ the use of a Fogarty balloon catheter to i2atroduce an endoprosthesis ~hrough a bile duct st~nosis. National Standard Medical Produc:ts, Gai:nesville, Florida ~ sells a marking needle with a retracta~le bzlrb for in~e~ie~n near a tu~or mass, as described in a produet descrip~ion sheet entitl~d l'Hawkins~ Elre~t Localization Needle. "
lMethods which rely on th~ p~rcutan~ous introduction of a cathe~er in~o the gall bladder and other hollow body organs ar~ ~escribe~l in copending application serial nos. 07/407,839; 07~529,077; and 07/551, 971, the disGlosure; o~ whiGh ar~ incorporated herein by reference.

According to the present in~ntion, impro~red apparatus and procedu3:es ~or: ~or~ing and enlarging percu~aneous penetrations into hollow body organs and ca~ities are provided. The appara~us co~prises an elorlgate ~irle ~e~4ber ha~ing pre~x~ma~. and dis~aLl end~ and Dl~ans îor ~l~aintalninq ~ guide memb~r un~r ~ensior durirlg the enlargement phase o~ the procla~lure.
Comr~niexltly, the ~:er1~iior 2~ns DIlay he a m@an~ ~or anchoring ~h~ guide mem~er.within ~he.boc3y cavity,.
Alternat.L~ely, the! ~en~ion means may 1;1Q a m~ans ~or con~r~ ing t:h~ st~ nl3s~ o~ the guid~ means alorlg all or 3 5 pa~ o~ it!3 laal~ . T~e appara~us ~urthQr cc~pri~es orl~
or more lalong~t6~ dilation m~bl3r~ which may 13~ in~toduc:~d to th~ body caYi~y oVe:r a path de~ined by lth~ guide :
.

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WO 92/0%~13 2 ~ 9 ~ ~ ~ 3 P~r/U591/08435 meD~ber. Tension on the guide member is aclvan~a~eous in at least two respects. First, such tension oauses the anchor means to pull outwardly against the inner surface o~ th~ ~ody cavity proximate the penetration, reduc:ing the tendency for the organ wall to deform or detach from surrounding fascia as the dilation mf~ber(s) ar introduced. Sec:ond, the tension minimizes the tendenc:y for flexible guide me~bers to buckl~ or become misaligned as th~ dilation members are introduced. Such buckling an~ misalignment can cau~;e tha dilation inem~ers to deviate from the desired penetrat~ on path.
The specific structure O:e the guide mamber and the dilator ( s ~ will vary depealding on the nature o~ the organ which is to be accessed. The guide member and/or dilators r~ay be substantially rigid or substantially flexible, depending on the tortuosity of the entxy route to the body casrity. For rQlati~ely accessible organs whach can be approached over a generally straight path, tha g~aide memb~r will usually be rigid and be intrQduc~d by ~eans of an integrally sharpened end or an intPrior ~tylet ir~ a manner si~ilar to the introduGtion o~ a . - s:2mnula. using a tr~ ar. For le~;s acces~ible organs which r~ire a tortuous apE~roach path, the guide m~er will u~ually be ~lexible iA the mann~r of a fl~xible guid~
- 25 wire. In either case, the anc:hor means on the guide ~ber will usually be retracta~ile or collapE;ible so that the guide memlb~r can b~ inse~d ( or r~m~aved~ with thQ
- ansfflor retractad, and th~ an hor e~tended only a~ter th~.
d~ stal end o~ the guid~ me~er has reached. ~he intE~rior o~ th~ body c:avity. A suil:able ~;ti ~nillg m~ans may :b~
an internal sti~fening wi:r~ which i~; ~;elec~ively i~3troducad to the ~aid~ mb~r to eXert ten~;ion o~reie t:he ngth of t~e me~ber by application of ~rce s:~n t~e distal end of the ~ember . The dilator ( ~i; ) wlll usually be . .
3 5 ~n~roduced directly ov~r th~ gui~e ~emb~r, typically ~;
u~iing a paE~E~age or ~;lot fo~m~d axially in ~he ~ila~ r to rQc:~ive the ~xterior o~ ~h~ e me~b~r. Alternatively, , . ,~ .

WO 92/08513 ~ 0 ~ 5 1 P~/lJS9~ 3S

a separatQ rail, track, guide wire, or thP like, may be at~ached to 'ch~ guide me~r and the dilators in~roducad over said separate el~ment~
.i In a first speci:Eic: eD~os:liment, tAe guide ra~mber i5 tub-llar having a central lum~n. The anchorincJ
m~3ans is a deflectable eleme}lt whis~h is secured near the dis~al end of the t~ular gulde m~mber and whi :::h is able to a su~e a retracted con~Eig~ratiorl within the lumen or an ~ended conflguration wh~re it proj~cts radially acro~;s the lun~en and ouk a~ aperture f or~d in the opposite wall o~ the cylindrical guide 3ne~ber. Usually, the de~lect~ble ale~ent i5 ~;pring-mounted so that it assu~es tha radially-proje~ ing c:on~iguration wh~n unc:on~trained. In ~he latter case, a stylet: will b~
slidably disposed within 1:~e lumen so that it can moY~e .. ~.
(and ~aintain) the de~lectable. ele~Qnt lnto it5 retracted con~iguratiorl. Thus, lthe asse~ly o~ the tubulair guide me~nber ~nd stylet can be first- introduced in ~h~ body cavity, typically with t~a~ . stylet hzl~ing a sharp~ d end to facilitat entry~ onc~ the. anc:hor- :meDlb~r is in plac:e, th~ stylet i~; removed . so ~hat the defle~:table el~ent ~.
a-~ ses its~ extended . con~ guration O . The guide m2~er can then b~ pull~d ou~w2lrds or-~ac~war~s so that ~he d~lectable ele~aen~: is: urg~.agalns~ ~e i~n~r surfas~:a o~
th~ body ca~rity and ten~3ion main~aine~ on t~e guidla ~e~er.. Whil~. ~air~tai~ing sueh t~nsion, a . dilator having an. a~ l slot can }7e introduced. o~er l:~e guide memb~r.
T~e axial. slt3t slidably rec:eiv~s th~ guide m~mber and is align~sl to. a~ o~odata..~h~ de~lectable el~ment. as th~
3~ elilator~ rea~ ... di~tal end o~: the ~ide me~er. Th~
~ilatox can be r2~0~rQd. and-replac~d by succç~s~iY~ly larg~r dilators in a . .siDlilar~ manner un~il a. pene~ration - havirls:a d~si.red diams~r-i~ forDl~d.. Tensiorl wi3l b~
m~intain~d on th~ guid~. meD~r during the entix0 3 5 proc~L~re 5C~ that pressure apE~ by the d~ c~
will..inhibi~ det3s:hml:3n~ o~ proxima~ wall of the body -orgalrl . or c:a~ri ty ~rozn .l~ ;urroundirlg f ascia .

WO92/08513 ~ 9 ~ -~ 5 ~ P~T/U~91/~8~35 Such tension further maintains alignment of ~he guide member through the initial path of the puncture ~hrough the successive layers of tissue and resists buckling of the guide me~ber caused by the applied compressive force of tha dilator(s). In thi~ way, the enlarged penetration will be formed along the desired path de~ined by the initial placement of the guide member.
In an alternate~ e~bodiment, the elongate guide member may be a flexi~le hollow m~mb~r, such a3 a flexible catheter or flexible guidewire. The flexible elongate me~ber ~ay be introduced to a dasired hollow body organ, either through a penetration, through i internal ducts and passages which naturally cnnnect to the hollow body organ, or through a combl~ation thereof.
After the flexible elongat~ me~ber is in place, an inter~al stiffening member, such as a ~olid core wire, is introduced through a central lumen of the ~lexible ~elongate me~ber so that the distal end o~ the stif~ening m~mber enga~es the distal end o~ the flexible ~longate mQ~ber. Th~ sti~ening ~e~ber may ~hen be used to apply te~sion on to ~he distal ~nd o~ the flexible elo~gate ~mber, thus sti~ning the r~sulting aæse~bly which includes both ~h~ flexible elongate ~er and the intexnal stif~ening m~er. The s~iffen~d elonga~e member asse~ly may ~h~n b~ used in order to intro~uc~ a larger dilator a~d~or working c~t~e~r over i~s exterior in a conventional ma~ner. ~n thi$ way, a ~uiding p~th i~
d~fined by tha a~ bly ~hi~h is ~uch stif~er than that whi¢h csuld be introduced initially, par~icularly i~
p~ssing through a tortuous pa~h. The stif~ened a~e~bly may provide addltional bene~its in cer~ain ana~omies.
~or tortuous path~, the stif~ne~ ber will ten~ to ~traighten ~ e path, frequ~ntly re~ucing the curva~ure and ~cilitatin~ th~ introduc~ion o~ ~h~
c~het~r~dilator. Th~ sti~en~d a~ambly ~ay also ~end : to imb~d or lock itself in plac~ within a restric~ed ~vo !)2/0~13 2 0 9 ~ 6 ~ ~ Ycr/us9l/0~3s pas~age further anchoring the Dle~bQr in place as a catheter/dilator is introduced thereover.
In an exemplary method according ~o the present invention, the flexible gllide member a~eembly j ust:
described i~ introduced to the gall bladder through th~
duodenum, t:ommon }: ile duct, and s::ystic du::t.

Fig. 1 illu~tral-es a spe~ ic dilator assembly cc1nstructed in accordance with the principles o~ the present inv~ntion.
FigO 2 is an el~vatiorlal view of the guide me~ber and stylet o~ the dilator asse~nbly of Fig. 1, shown with the guide me~b~r in section.
Fig. 3 is a front end view o~ the dilator ele~enk o~ th~ dilator assembly o:e Fig. 1.
Fig. 4 is a cross-s~3ctiorlal view o~ l:he dilator el~Dient shown with the guide me~ber in place.
Fig. 5 is a cross-~ectional view taken along 1 tne 5 -5 o~ Fig . 4 .
2 o Fig 0 6 is an alterna~e e~odiment of th~ ~ide member which can be us~d Wit21 th~ dilator of Figs. 1 5.
Fig . 7 i~; a ~;econd alterna }:e e~odiment of the , -~ide ~ember of the presl3nt invention th.at can b~ us~d with the dilator o~ Figs . 1- 5 .
. 25 Figs. 8 and 9 illustra~ a third al~rnate embodi~ent of th~ e me~r o~ th~ preF:~nt invelltion ,:
l~at ca;n be u~ed with the dila1:or of Figs. 1~5.
- F~ gs. ~0~1~ illustra~ a ~e~hod per~e~rffled in acc:ordance with tha princ:ipl~si of tha prQsent inv~n~ior utili2iny the dilator asE;embly o~ Fig~ 5,.
Fig . 13 illustrate~3 an apparz3 tus constralcted in a~ ordancQ with th~ prin iple o~e th~ pre-~en~ inven~io u~ful ~or introducing dilator~ 0r wor:king c:ath~tQrs ko hollo~ hody organs ~rou~h tort.uous pa~hs.
3 5 Fig . 14 is a det~iled vi~w o:e the pro;cimal encl o:e th~ apparatus o~ Fig~ 13, showr~ in CrO~;8- :3ec~ion.

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wO 92/08513 2 ~ 9 6 6 ~ 1 P~T/U~91/0~4~5 Fig. 15 is a d tailed view of the distal end of the apparatus of Fig~ 13, sho~ in c:ross section.
Figs. 16~18 illus~rate the use of the apparatus of Figs. 13-15 in introd.ucing a working cathe.~r to the gall bladder i:n a retrograd~ manner.

Th~ pres~nt in~enti3n is use~ul f or f orming and dilatirlg per ::utaneous perle1:ratiQns into a vari~ty o~
hollow organ bodiQs and cavi~ies for a multiplicity o~
purposes. The sizes of the initial pen~trations and 5ub ecluent dilations are not critical and may vary widely. 'rhe initial pera~tration will usually be a ver~
small pun::ture formed u~;ing a needle or other small instrumerlt in order to rainimize trauma to the patient.
Depending on the targat organ9 th~ punc:ture instrument ~ay have a size in the ran~e ~rom about 3 French ~F~
(where one French equals 0 . 33 Dlilli~ete:rs) to about 8 F, and usually being in the range from about 4 F to ~ Fo The initial penatration will typically he dilated to a ~ al di~n~ter from about 10 F to about 30 F, ~ypiGally J b~ing fro~ abou~ 12 F to 28 F an~ usually being fromabout 14 F to 24 F, with the pre~ent invention being part:ic~larly use~ul for th~ ~o~ation of la:rger dialQater p~netxations~ The purpo~e o~ th~ penetr~iorl s:an be ~or drainage, intraorgarl drug ad~uinistration, :~eeding, p~rfu~ion, aspirationt or th~ liXe, l~ut will usua~lly b~g for the introductioll of a relati~rely large worki~g :: cathQter, such a~; th;:s~ inltended for int~arvesltio2lal procedures . Such inter~rentional procedures in ::lude lapare~copy, balloon di:La~a~iorl oi~ duc:tsv E:lac~m~n~ o~.
s~e!nts, and thQ l~ke!. Pene~ra~ions ax~ particularly . suitabl~ for tha plae:e~lan~ o~ ga~;troi~te~1nal ~ee~in~
... tllbes a.s well as ~or ~e introsluction o~ th~nnal ablaLtion - cathetar~, suc:h a~; tho~e described in co-pQnding .
applicàtions serial nos. 07/~07, 829: 07/52g, 077; alld 07/551,971, pr~viou~;ly incorpora~d her~in by r~erer~ e:

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. , ' ' ' '. , ' ' ' . ' ' ~ ' "' ." ' ' . : ' : ' ` . ' ' ' ' Wo 92~08513 ,~ ; fj 5 ~ P(::T/US91/~)8~35 ,, The percut~neous pen~trations may be f ormed into virtually any hollow body organ or cavity, particularly including the gall bladd~r, stomach, urinary bladd~r, uterus, kidney, portion~ of the lung, and the like~ The methods and apparatus of the present inventic:n are also useful ~or providing penetrations into blood vessels aIld other small hollow bocly structur~s and ducts.
The latter penetra~ions will oft~n require a flexible guide member to gain ac:cess while ~he former penetrations can frequently }: e achiev~d with a relatively rigid guid.e member .
A dilation as~;e~bly a~cording to the present invention includes an elongate guide m~mb~r which def i~lQ5 a path for the intrc:duction of on~ o:r more dilatioA
memb2rs into the body cavity. The guide m~mber will have proximal and distal ends ~ and may have a g~nerally flexibl~ or rigid structure, depending on the parti~~ular application. Rigid guide ~2mber~ will g~nerally be ~mployed wh~n th~ targ~t oryan ~ay be approached along a ~ubstantially straight pa~h, whil~ flexible guide m~mb~rs will normally be used when a tortuous path ~ust be --, followed. Rlgid guide members ~ay be formad from metals, typically tainless st~el, rigid plastics, and thQ like, while ~lexible guide ~e~ber~ will typically b~ fo~ed ~ro~ coiled ~tainle~s ste~l. or Nltinol~ wire or from : extrud d organic polymer~, such as silicone rubbex, polyur~ ~ ane, polyvinylchloride, nylon, and the lik~. In the la~t~r case, rein~orc~ment- ~ay be provid~d in order to.pro~ide ~ particu1ar degre~.of.~lexibility suit~ble for tha intended application.
The length-of th~ g~id~ m~r will ~a~y~ wi~h shorter g~lide mem~ars ha~ing length in th~ ra~ge from about ltl t:o 20 ~ b~ing ~suit~bl~ ~or ae~sing body ca~iti~i which ~r~ near th~ surfac~ o~ ~he skin, su~h a~
the stoDIach. Lonqer guide m~r~ having a length in ~he rang~ Xro~ about 20 ~o ~0 ~ will b~ sui~abl~ ~or body cavitte~;, such ~s th~ ki~eyO Even lo~ger flexiblQ

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W0~2~085l3 ~ 9 ~ ~ ~1 Pcr/lJs91/u~3s members in the nature of a ~uide wire may be employed ~or inserting dilating mem~ers to blood vess~ls and other remote ducts. In such ca~es, the lenqth o~ the guid~
wire may be in the range from about ~0 cm to 150 cm, ox longer.
Genexally, the shorter guide members which are u~d for acces~ing l.ess re~ote body organs along a straight path will have a generally rl~id structure, while lony~r guid~ m~mber~ intended ~or accessing ~ore remote body organs and ducts along a tortuou~ path will have a flexible structure. This correlation, howeverf will not always be the case, and it may ~requently be desirable to utilize a flexible yuide m~m~er to access hollow body organs along ~hort, straight acres~ paths.
The guide me~ber ~ay have a solid cross-section, i.e~ in the form of a solid rod or wire, but more usually will be t~bular having a central or axial lumen ther~through. Th~ axial lumQn allows the guide member to be introduced using a ~tylet (as described in ~ore detail hereinbelow) or in th~ ca~e of flexible guide m~bers, to be introduced over a movable guide wire in a conventional mann~r. In ~o~e ca~s, of cours~, ~h~ g~ide m~mber it~ may b~ in tA~ nature of a guide wire, e.g., : being fo~med from ne~ed coils in a ~nown mann~x.
~ans ~or ~aintaininy the guide me~ber unde~
t ~ sion will be provided in combination with th~ guide ~r. U~ually, th~ t~nsion m~ans will comprise an anchor ~e~ns located n~ar th~ distal.Qn~ of the guide ~emb~r, wh~reby th~ distal ~nd may ba secured WlthiM th~
hollow bo~y organ or.other.re~o~e, location and ~n~ion~.
y ~e applied by pulllnq outwardly on ~he proxi~l end o~ tha ~uid~ mem~sr which re~ains ext~rnal to th~
pati~nt.~ O~her tension ~n~, how~ver, ~ay al~o ~ind u~e. For exa~ple~ a separate elongat~ stif~ening m~mb~r ~ay b~ in3~rted coaxially within Qr ou~sid~ of ~h~ guide in or~r to proYid@ a de~ired t~n~ion ~h~reonO
Alt~rnati~ely, the t~nsion me~ns ~ay co~prise m~an~ for .

~,' . ` ` ~ ' , `~0 92/OR513 ~ PCr/US91/0~35 interrlally pressurizinq the guide member in order to ' provide the de~ired elongating ~ension. Other approa ::hes ~or tensioning the guide member will be obvious to those skilled in th~ art in view o~ thE~ teas::hings herein.
Means f or anchoring the guide member within ~he hollow body organ will p:rovided at or near the distal end of 'che guide m~m~er. The anchoring mean~; will be typically rel:ractable or c:ollapsible so that the gu1de Dlember c:an be introducsd and withdrawn without interferenre from the anc:horO ~he anr~hor means is selectively extended or ~xpanded outward ~rom the guide mamber so that it can ~ngage a structure within thP
. ' J hollow hody organ or a n~ar~y region. Tension .is the;
applied by pulling or drawing outwardly on the yuide - 15 me~ber. In a situatiorl where the guid~ member p netrates a body cavity, the anchor w.ill usually engage a region of th~ inner surface o~ ~h~ bocly cavity proximat~ the penetration~ 13y thus maintaining a constant t~n~ion on the anehorins~ m~ans, 1:he wall o~ the body cavity can b~ ::
- 20 h~ld in plalC@ and prevQnted ~ro~a detachir~g fr~m thQ
proxi~al and ~urrourlding faicia during~ sul3se~ent ~alation proc:~adurQs.
Th~ structur~ o~ th~ anchoring means i5 ncst critical. For e~c2~ple, the anchoriny means may be an inflata~le bal~ oon whit:h, when in plac~ within a r~3trict~,d regiorl o~ th~ be~dy organ or adj ac:ent duc:t ~ m~y b~ in:~lated t:e~ bec:o~l3 lodg@d therQin.. Alt~xnatiYely, the hor mi3Ly be a portion ol~ a flexible guid~ mem~er, wh~re ~- th6! porl:ion may bE~ st~f~en~d so that it will becom~
lodged ~within a tor~uou~; region of il duc~ or hs:~llow orgar to pr~vlent withdraw~l o~ ~ide me~ber. conv~niently, the a~cho:r c:an b~ a d~g~lec:tabla e3.e~nt ~rhich i~ actuat~d ~eeh~nically,, ~uc:h a~ using a cabl~ or o~l~r actuati:;~
~ean~ wit~in 1:h~3 guide m~nb~rO Alt~3rnat:ively, tha de~i~lQc:tabl~ nt c:~n b~ orme~ ro~ a ~hapQ me~ory alloy which i~3 rele~e~l :rom a res~rainin~ s~nac~urQ or VO 92/08513 2 ~ P(~/V~91/1)~43 selQctively ac-tuated by a h~atar which is externally powered .
In an examplary embodi~nent, the anchoring m2ans is a ~pring~mounted de~lectable finger which is mounted S on the inner wall o~ a tubular or cylindrical guide m~mber 5 When unconstrained, the f inyer extends laterally through an aperture in the opposing wall so that it may engage ths inner surface of the body organ. ~umerous alternati~re mechani ::al, electrol~ec:hanical, and other syst~ms ~or providing a deflectable element or other anchor means will be apparent to those skilled in the art .
The system o~ the present invention will include one or morQ dilation members which include a means ~or ~ollc3will~ the path d~fined by the guide m{~mber when it extends pexcutaneously into ~he hollow body organ. In a pre~erred Pmbodiment, the system will include a plurality of dilation members which ar~
generally similar in construs:tion, bu~ which have ~uc~ essiv~ly larger cros~-sectional areas so that the 5i2e of the percutan~ous pen~tra~ion ca.n be increas~d by introducing su~cessiY~ly large:r dila~ors over the guide meD~er. Usually, the path follQwing m~ans will b~ an axial channel form~d c~n orl~ si:le o~E thQ d.ila~or so ~h21t it: can be pa~sed o~r khe quide laember while allowing cl~arance ~or 'che de~ table ~le~a@nt. When the dilation me~b~r includ~s an a~ia~ channel, it wi~l be desira~le to provide }ceying means near th~ proximal end of the guide . m~ r so that the slot on ~h~ axial chamlel m~y lbe radially aligmad with th~ nchor mQan~ on ~e ~is~l end o~ the gui~de member~ In this Way~ the slo~ will n~:essarily b~ able to pass the a3~6horing~ an~
raslially exterlding d~ ctalble ~ n~, when ~he dilakor reache~ th~e anchoring ~eans. ~sually, ~e ~ila~or will b~ tap~red at it~3 di~tal end ~o facilitate p~ 2~ration, and the dila~tor may optionally include OnQ or more additionzll lu~ens f or other purposes, such a3 the.
:

~'O 92/08513 2 ~ 9 ~ 6 ~ 1 PCI'JIJ~91/08~33~

introduction of a separate movable guide wire which can rem in in placa after the dila~or and guide member are removed from the enlarged penetration. The dilation m~ers will typically ha~ve cir ::ular cro55-~ections although other cro~;s sectional shapes might also f ind use .
Th~ size of th~ dilation members will typically vary from relatively sma~Ll, i . e. as low as about 10 F, to relatively larye, i.e., as large a~; about 30 F. The incremental increase in size between success~ully larger dilators will typically be on the order of about 3 F to 6 F, more usually being about 4 F to 5 F. Thus, it may be nsce~sary to amploy as many as about f ~ ~re dilatr: rs to ~o~ a relativaly large penetration on the order o~ a~out 30 F. Of course, the permissible incremental im:re~se in the dilator size will depeaad greatly on the elas~icity o~
thQ tis~ue being dilated, t:hQ f2-agility of t21e att~ac:hmer:
of ~e ~ody organ to the surroundi~g fasc:ia, and the be!aring sur~ace area of ~a anchç~r being utilized. Where th6~ tis3i;ue elasti ::ity is lower, faE~ia attachmerlt ~uore fragile, and/or the bearing surfa~e area r~duced, ~h~ :
- -~ i~ere~ental increase ir~ dilator dialaQter should be smaller.
Re~errinq now to Fig~;0 1-5, a dila~or assembly 10 construG~ed irl accordance with the principl~.s o~ th~
pr2513nt in~ention i;adudes a stylRt. ll having a sharpened dis~al end 12 an~ a handle 14 ~ at i~s proxim~l end7 ~h~
style~ 11 is rec:eived in an ax~ al l~nen 15 o~ a tubular - guide 21le,~ber 16 ha-ring a proximal ~nd 18 and ~listal end 20~ A d~fl2::table elem~nt 22 is di5po~;Qd in the lu~en-15 having its length generally aligned with the axi~; of the lumen ~wh~n th~ stylet 11 .is in po~;iltion). An ap~ ura ~ ~ 24 i~ i~o~med in th - wall of the $ubular guidl3 ~b~3r 16 - at a location generally opposite to that $`rom the dQ~l~atable ele~nt 220 Th~ deflectable ele~ent is a 8p?rirlg Which in it~ unco~ Eainecl con~igUratiorl (i.e., with th~ ~;tylet ll r~oved. from..a~ l. l~erl 15) ,, a~ume5 : ~

- WO 92/0~513 2 0 9 ~ P~r/us~ 435 the radially extended position illustrated in br~ken line in Fig. 2 and. in solid line in Fig. 5. With the stylet in place, how~ver, th~ d~flectable elem~nt 22 is deflec~ted s~ownward in a retracted position, a~;
illustrated in full line~ in Fig. 2. In this way, the de~lectable element 22 is in its retracted configuration when the assembly o~ the guide member 16 and s~ylet ll is introduced to or withdr2lwn from the body ca~vity, as de!ci::ribed in more detail hereinafter. The de~lectabl~
element 22 may be relea~ed into its extended c:onfiguration by simply withdrawiny the stylet ll which allow~ the de~le~table elem~nt to assume its unc~nstrained configurakion, as illustrated in Fig. 5.
The third component of the dilat~r assea~bly lO
is a dilator 30 which is a generally cylindrical tube having a tapered distal end 3Z and an axial slot 36~ T~e axial lumen 34 i5 sized so that it may pass ov~r the exterior of guide memb~r 16, whil~ the slot 34 will be ~ufficiently large to snap over t:he guide ~n~berO Th~ -2 0 opl3ning of slot 3 ~ pro~ride~; clearaFIce so that the dilator ` 30 may be advanc~d past the de~l~ctable element 22 when - the dilator 3 0 i~3 introduced into ~la body cavity, a~
. d6~scribed h~reinafter. Such cle~rar~ is hest observ~d . - in Fig . 4 . Keying means, su~:h as tab 3 7 ~orm~d on th~
di~tal end of ~ide mQmber 16 (Figs . 1 and ~ ), as~;ures that the slot 3 6 will be properly aligrled with the deflectable ele~ent 22 a~3 ~e dilator 30 i8 ad~a.nced forwardly down the ~ide ~b~r. ~ lumQn 40 is ~ ap~ionally provided in the ~lilator 3 0, and c::an be used 3 0 ~or introdu~ing a guide wîre into the p~rcutaneou~
penetration a~t~r ~he dila~ion procedure has been coDIpleta~. once pa~sinq ~che guide wire in through ~h~
: ~ l~en 4 0, t~e entire dilator asse~3ly including the dilato:r 30, guide ~ber l6, and stylet ll may be ren~oved 3~ le~ving lthe guide wire in plac~. .
While only on~ dilator 3 0 ' ~; illus~ra~d, it will bls ~ppraciate~ ~a~ a plurali~y o~ di~ators ~aving .
^' ~1 ~ ., .

I '':, ' ,. "j~' , , . ' . ',' ' ', ' ' ' ', '. ' ,', ': ::: ' ' ' ~0 92/OX513 2 0 9 6 6 ~ :1 pcr/us91/o~35 successively larger diamet2rs may be provided in order to practice the method of the present invention, as described in more d~tail hereinafter. A particular advantage of the present inv~ntion d~rives frvm the maintenant::e of tension on the guide member which results in a compressive force on the tis~;ues which are being penetrated, SUch a c:ompre~;sive force tends to hold various layers o~ the tissue togethPr as the dilator(s) are introduced, allowing t:he use of larger diameter dilators than would othel-wis~3 b~ possible without tearing or separating tissue layers. Thus, the tutal number o~
dilators required to achieve th~ penetration of a given size m~y be reduced.
Referring now to Figs. 6~9, cons~ tion of s~veral alternative anchoring msans will be dP-scribed.
In Fig~ 6, a guide memb~r 50 comprise~; a hollow ne dl~
having a sharpen~d distal tip 520 An ap~rt7lra 5d, in thQ
side o~ the guide member 50 allowE; a spring tip 56 of an anchor wire 58 to project ou~wardly, 21S illustrated in broken line. Init~ ally, the ~;pring tip 56 is ~ully double -back (as ~hown in the right hand brok~n lin~
position~, an~ the spring tiE3 moves out through the ape~ure as the anchor wir~ is drawn prvximally ( to the left in Fig. 63. In this way, the ~ide memb~r 50 may be illtroduced through a pre-formad inci~ion and dilatort~) simil~r to those illustrated in Flgs. 1-5, introduced thereov~r after th~ ~pring tip 56 has beerl released~
The guid~3 m~r c~ Fig. 6 can be modified to permit introductic~n using a r~moYable stylet, similar to 3 0 ~ ~tylet 11 in Fig~; ~ 1 and 2 . In ~;uch a mQdif ication ~ not illustratl~d~, sharperled tip 52 would b~ remo~red ~rc~m ths sh ~t, and th~ distal tip le~t open. ~he guide ~ember 50 would ~hen b~ roduc~3d with ~che stylet p:roviding the sharp~n~d tip. A:Eter plac~ment Q:e t}l'~ guid~ memb~r7 the s~ylet would b~ r~moY~d and the anchor wir~ 58 will b~
in~rted into the lum~rl o~ the guide wir~. op~ionally, ~he anc.~or wir~ could be contained in a loading ' .

.. :, .... . , .. , . . .,; ~ . . ., ; . ~ -~VO 92/08513 2 a 9 6 ~ PCT/US9l/08~35 which maintains the wire in it:3 folded configuration as it is inserted into th~ guide member.
A second alternative anchoriny means i5 illu~trated in Fig. 7, where a guide memb~r 60 having ar S open distal end 6~ receives an anchor wire 64 which has an "L" sh~ped tip when uncon~trairled. Th~ guide me:mber 60 may be introduced to a hollow body c:a~ity over a separate guide wire t removable hub, o:r needle in a corlventiorlal manner . Con~ersely, the guide member 6 0 may be introduced with a ~;harpened stylet whic:h is subsequently remov~d. Aft~r option~lly removing the stylet, guid~3 wire or needle, th~ anchor wire 64 may be ~, inserted so that a forward spring tip 66 is released from the open distal end 62 and asæu~es the deflected con~iguration shown in brokerl line~ Conv~niently, t:he anc:hor wires 58 tFig. 6) and 64 (Fig. 7) may be ~onned froDI a conYentional spring stainlesE~ st~el or :~ro~ a high ~e~or~ alloy, such as NitinalD'. A loader tub~ which eon~train~; the spring in an appropriate attitude could be 2 0 used to si:~plify loading .
R ~errirlg now t~ Figs.., ~ and 9 ~ a ~hird alternate e~bod:Lmerlt ~Eor a guide m~ber 7 0 is illustrated . Guide me~7~r 7 0 includes an oul:er rigid cannula 72 an~ an i~er se~nted rod 74. Rod 74 -' 25 ins::ludes a distal segment 76 having a shaLrp~ned distal tip 78, an intermediate ~e~ant 80, and a proxi~al ~e~t ~2 ~ Th~ segment~ 76, 80 ~ and ~, axe genQrally hollow and h~ld togeth~r by an ela~ic m~er 8a~ which is secured within the distal ~;~gment 7 6 by a swaged region 86 formOE~d in . the distal s~gm~nt. A~t~r th~ guid~ r i~ in place with its ~ ;tal endl within ~he desir~3~ region o~ th~ hollo~ 1: ~dy c:av:Lty, ~h~ o~ater caD~ula 72 may b~ !
- wi~drabm in the prox~mal dire~ion so ~ha~ ~he di~tal s~la~t 76 an~ inl~em~edlate seg~en~ ~0 o~ ~e i~er rod 74 ar~ expos~d. In e~rd~r to collaps the di~;tal ~trlacture o~ the rod 74, te~a~ion laay be. applied ~o a ~utur~ 88 which i~ cured to Sh~ tip o*. di~;tal s~ nt ~ .. 1 .

'tO92/~8513 PCT/VS~1/0~35 2096~1 1~
76 of the rod member 740 In this way, the distal seqment 7~ and inter~ediate segment 80 may be collapsed to the configuration illustrated in Fig. 9. Dilating members . (not illustrated) may then be advanc2d over the outercannula 70 with th~ collapsed segments 76 and 80 of the inner rod serving as the anchor means.
Referring now ito Figs. 10-12, use of the dilator assembly 10 of F:i~s. 1 5 for forml~g a p@rcutaneoug pe~etratlon throug~ the ab~o~en A into a ~tomach S is illustratad, ~nitially, th~ as~embly 10 inclu~ing the guide member 16 and stylet ll i9 introduced through the abdominal wall A using ~he sharp protruding end 12 of the stylet to provide access. Optionally, an initial penetration could be made u~ing a needl~ or other penetrating device. After the guide member 16 has been introduced, the stylet l~ is removed, allowing ~he d~flectable element 22 to a sum~ its ext~nded con~igur~tion ~rom guidQ m~ber 16, a~ illustrated in Fig. 11. The guide mQ~ber 7 6 i~ then pulled outwardly in ~-. 20 ~he direction o~ arrow ~0 so ~a~ the d~lectable el~ment ~- 22 engages the inner surfac~ IS o~ ~he stomach in the region o~ the pene~ration. A~ illus~rat~ in Fig. 7, placing the guide ~e~ er 16 under t~nsio~ pulls the inner wall o~ the sto~ach S against the overlying ~ascia. A
first dilation member 30 ~ay ~hen be in~roduc~d over the guide member 1~ while maint~ini~y tension on th~ guide m@mber 16, as illustrated in Fi.g. 8. The number and size - o~ dilators 30 whi~h ar~ fi~ally used will ~ep~nd on the d~sirad size of the percutaneous penetration. After th~
de8i~d size is achiaved, ~h~ ten~iQn is rel~aæed by ~ovin~ guide m~er 16 ~orward to ~isengage ele~en-t 22 ~rom the inner suxface I~ o~ stamach S. A guide wir~ may - optionally be introduced ~hrou~h a ~econd lumen 40 ~Flg~.
2-5) that may be incorpora~e~ into the larger dila~ors.
: 35 The stylet ll will bQ r~introduced to the ~uide member 16 so that the d~lQc~able elQment 22 is r~racke~. Th2 dilator 30, gui~e ~e~ber 1~, aad styl~ ~l may t~en be :i 'I

WO 9~/08513 19 PC~/U~91/0B~35 withdrawn from the penetration, leaviny the guide wixe in place within a reiati~rely larg~ trat:t suitable for insertion of a large sheath or working cathete:r.
Referring to Figs. 13-15, an elongate guic3~
member assembly 100 includes an outer flexible tu~ular ~1~;5~ y 102 and an inner stiffening memb2r 104. The outer ~lexible t~abular m~er 102 ter~inates in a t~readed recep~as:le 106 at its proxiDIal e~d and in a nge element 108 at its distal Qnd. Comreniently, a Dletallic ring 110 i5 prc~vided in order to pxovide a stop ~n~mber :Eor the inner sti~fening ~ember 104, as d~scribed in more detail hereinaîter~
The nature o~ th2 outer ~lexible tllbular me~er is not critical, and it may ~8 in the ~orlQ of a hollow polymeric tube, a metallic gu ~ewire, or the like. The_ tubular member 102, however, should be suf~iciently :1~xible so that it can be introduced through a relatively tortuou~ passage to a hollc~w body organ, a~
will be describ~d with. ~peci~lc r~erQnce to retro~radQ
acc~ss to tho gall bladder h~r~inafter.
~he imler ~;tifiEenirag lae;nber 104 t~rmin~t.~; ak a male thread ele~ent 112 . a$ i1: . proximal en~ ur~ r having a knob at~ach~ to ~acili~a~e ~urning. A pin 11~
having a rounded head proj~c~s ~rom the di~;~al end o: the : .
ia~n~r sti fi~ening Dlember 104, and the pin 116 and 3tiIfening me~ar 104 ltogether de~ine a shoulder 120, as b~;lt s)b~erved in Fig~ 15. I~a thi~3 way, the inner sti~ferling me~r 104 ~ay b~ inse~:e~ in~o lum~n 12~ o~
th~ ~lexi3:~1e tlabular mem~r 102 ~til 1:he shoulder ~2Q
e~lgage~ ~ stop ri~g ~10. By ~hen tightening down on:
thQ thr~aded m~mber ll~ wikhin th~ housing 106, terlsion c:an ~e applied to ~e ~lexibl~ guide meDab~:r y ca~ ag a ~tl~fening of the ~aber along its; antire length~ Such a :~ti~ened guid~a asse~ly 100 prQvides an ~xcellen~ path i~o~ introducing a working ca~hQ~er, ~ila~r, or t~ae like.
to holl~w body organ. Th~i s~lr~erle~ guidQ ~Qe~ r reis3i~3t~;
lbuckling, mi~alignxlien~, and o~ r de~c~rma~ion whieh mi~ht ~; .

. ;. :

: . - , ~., ` '' , `~.; `' '; ~ '', . , ' " . ' ' ' ' "

VO 92/0~513 2 0 9 6 6 5 ~ pcrJlJs~l/o8435 occur as the working catheter, dilator, s:r the like is introduced thereover~ The stif~ened member will additionally tend to straighten the tortuous path, improving acce~s, and can further result ih anchoring of the stiffened distal end, particularly when the stif~ened end becomes lodged in restricted passages.
Referring now to Figs. 16-18, the introduction of a working cathetQx to thQ gall bladder GB through the duoden~ D, com~non bile duS~t CBD, and cystic duct t~D, will be desc:rib~d. The ou~er ~lexi3:~1e ~ube member 102 is f irst introdut:ed through th~ path j u~;t desc:rib~d . The high fl~xibility of the outer flexible tlabe member lOZ, alonq with its small diameter relative to the working catheter WC~ allows it to easily pass through the ~orl:uous path which is ancountere;:l ( Fig . 16 ~ . A~ter the outer flexible tubular member 102 has bee~ introduced, thQ ins~er stif~ening member 104 will be inserted through ~e lumen 122, and tension will b~ applied in or~er ~o stiffen ~e r~ulting assembly 100. AE; can be seerl in :-; 20 : Fig. 17, suffic:ient ~ension will b~ applied to g~nerally st:raig~ten the resulting aE;~sembly ~00 ~ partic:ularly rough the tortuous ::ystic duct.
Finally, r~erring to Fig. 18, a workin~
~::atheter W~ (or ~l~xiblQ slotted dilatar) can b ,i ' 25 introduced ov~r the exterior- oi~ thF~ elongate guide me~b~sr ~: a 8el1~bly 100 in a co2l~renltional :manner. 3rhe tension provid~d }:y inner sti~ ning me~ber. 104 helps maint:ai~
U ~ ali~ent of the guis~e member- a~e~bly 100 whil~ t}
~c3rking catheter W~ i~ b~ strodu~:ed, i?reventing 0 wi1:~d.raw~1/ buckling, kir~ing, and oth~r deformation o:~
the qu.idQ member a~ ~e s:athe~Qr i~3 a~vanced in th~
~is~l direction~ Con~reni~ntly, ~ wo:rlcing c:athat~r ~7C
. ~ur equ~ralent dllator) ~nay in::lud6! a E3lakted ~ aerl (not illustral:ed) along all or part o~ i~s le.n~th to 3 S ~acilitate introduci~g the catheter over the guide me~er a~ Ly 100. Alt~ a~ively, ~he worXirlg cath~ter WC~ ~or dilator) ma~ ba pre-Dloac91ed 03~ a proxi~al: length o~ th~
, . .- .

: . .
~,.,,, : .
, ; : , WC~ 9~/0~3~l3 2 ~ 9 6 ~ 3 ~ PcT/us~1/08q3s guide member as~embly loo while the assembly is introduced and stiffened. The working cathe~er ~c s::ould then be moved forwar~ a~er t~e dis~al end of the g~ide m~ber a~sembly 100 is in place.
AlthGugh ~he ~or~goiny inven~ion has been described i~a detail ~or. purpos~s of clarity of undarstanding, it will be obvious that certain ~difications may be prac~iced within the scope of the ~ppen~ed claims.

' ' '.
.'. ~' .

'^ ` .

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., ' , .
., , :. .
, . ......
.~, 1 , .

Claims

WHAT IS CLAIMED IS:

1. An apparatus for forming a percutaneous penetration into a body cavity, said apparatus comprising:
an elongate guide member having a proximal end, a distal end, means near the distal end for anchoring the guide member against a surface of the body cavity near the penetration; and an elongate dilation member including a tapered distal tip and means for following the guide member into the body cavity.

2. An apparatus as in claim 1, wherein the guide member is rigid.

3. An apparatus as in claim 1, wherein the guide member is flexible.

4. An apparatus as in claim 1, wherein the means for anchoring includes a deflectable element having a retracted position substantially within the elongate guide member and an radially projecting position, whereby the guide member may be percutaneously introduced with the deflectable element in its retracted position and anchored against the body cavity surface with the deflectable element in its radially projecting position.

5. An apparatus as in claim 4, wherein the deflectable element is a spring or is spring-mounted so that it assumes its radially projecting configuration when unconstrained, said apparatus further comprising means for constraining the deflectable element in its retracted position.

6. An apparatus as in claim 5, wherein the elongate guide member includes an axial lumen wherein the deflectable element is mounted and wherein the means for constraining the deflectable element comprises a stylet which is slidably received in the lumen and which engages the deflectable element to urge said element into its retracted position.

7. An apparatus as in claim 1, comprising at least two elongate dilation members having different sizes so that the dilation members may be successively introduced over the guide member to incrementally enlarge the percutaneous penetration.

8. An apparatus as in claim 4, wherein the means for following is an axial lumen having an axial slot for accommodating the deflectable element.

9. An apparatus comprising:
a tubular guide member having a proximal end, a distal end, and an axial lumen therethrough;
a stylet which is slidably received in the axial lumen of the guide member;
a deflectable element near the distal end of the guide member, wherein said deflectable element assumes a retracted configuration when the stylet is in place and assumes a radially projecting configuration when the stylet is removed; and an elongate dilation member having means for passing over the guide member and clearing the deflectable element when said element is in its projecting configuration.

10. An apparatus as in claim 9, wherein the stylet is sharpened at one end and is sufficiently long so that said sharpened end will extend beyond the distal end of the cylindrical guide member when the stylet is in place within the central lumen, whereby the sharpened end of the stylet facilitates percutaneous penetration into a body cavity.

11. An apparatus as in claim 9, wherein the deflectable element is a spring-mounted finger that is retained in an axial orientation when the stylet is in place and assumes a radially projecting configuration when the stylet is removed.

12. An apparatus as in claim 11, wherein the tubular guide member has an axially elongate aperture near its distal end and the spring-mounted finger is disposed on the inner lumen wall opposite the aperture so that the finger will project radially outward through the aperture when the stylet is removed.

13. An apparatus as in claim 10, wherein the means for passing the elongate dilator over the guide member includes an axial lumen and slot which slidably receives the guide member while allowing clearance for the deflectable element in its laterally projecting configuration.

14. An apparatus as in claim 10, including at least one additional elongate dilation member having a larger cross-sectional area than the first dilator.

15. An apparatus comprising:
a tubular guide member having a proximal end, a distal end, and an axial lumen therethrough; and an anchor wire slidably received in the lumen of the tubular guide member, said anchor wire having a spring tip which projects laterally from the guide member when the wire is moved to a preselected axial position within the guide member.

16. An apparatus as in claim 15, wherein the guide member has an aperture in its side wall, wherein the spring tip passes through the aperture where the anchor wire is in its preselected axial position.

17. An apparatus as in claim 16, wherein the spring tip is constrained within the guide member in a doubled-back configuration and is released by drawing the anchor wire proximally within the guide member.

18. An apparatus as in claim 15, wherein the distal end of the guide member terminates in a sharpened tip.

19. An apparatus as in claim 15, wherein the spring tip is constrained within the guide member in an elongated configuration and is released through a distal port on the guide member by extending the anchor wire in the distal direction, whereby the spring tip folds back upon the anchor wire to project laterally.

20. A method for enlarging a percutaneous penetration through tissue into a body cavity, said method comprising:
introducing an elongate guide member into the body cavity through a penetration;
applying sufficient tension to the guide member in order to inhibit buckling and misalignment of the guide member; and advancing a dilation member toward the body cavity over the guide member from outside the penetration and through the penetration while tension is being applied, wherein said dilation member enlarges the tissue penetration.

21. A method as in claim 20, wherein tension is applied by anchoring the distal end of the guide member and pulling outwardly on the proximal end.

22. A method as in claim 20, wherein the guide member is flexible and tension is applied by passing a stiffening member through the guide member.

23. A method as in claim 20, wherein the guide member is flexible and tension is applied by internal pressurization of the guide member.

24. A method for enlarging a percutaneous penetration through tissue into a body cavity, said method comprising:
introducing an elongate guide member into the body cavity through a penetration;
positioning the guide member so that an anchor near its distal end is drawn against a surface of the body cavity near the penetration; and introducing a dilation member into the penetration toward the body cavity over a path defined by the guide member while said anchor is being drawn against the body cavity surface, wherein said dilation enlarges the tissue penetration.

25. A method as in claim 24, wherein the elongate guide member is introduced with the anchor in a retracted configuration and is positioned by extending the anchor and thereafter drawing the extended anchor against the body cavity surface.

26. A method as in claim 25, wherein the guide member is positioned by pulling outward so that the anchor engages the body cavity surface.

POT/US91/084?

27. A method as in claim 24 1 wherein the dilation member is introduced directly over the guide member.

28. A method as in claim 24, wherein the dilation member is introduced over a separate track element which is secured to the guide member.

29. A method as in claim 24, wherein the guide member is introduced over a guide wire.

30. A method as in claim 24, wherein at least a second dilation member having an increased diameter relative to the first dilation member is introduced over the path defined by the guide member.

31. A method for introducing a catheter to a hollow body organ, said method comprising introducing a flexible elongate guide member through a passage to the interior of the hollow body organ;
tensioning the guide member to increase the bending stiffness thereof; and passing the catheter over the guide member and into the passage toward the hollow body organ while maintaining the tension, whereby the increased bending stiffness inhibits buckling and misalignment of the guide member while the catheter is being passed thereover.

32. A method as in claim 31, further comprising passing at least one additional catheter having a larger cross-sectional size over the guide member while maintaining the tension, whereby the size of the passage may be dilated.

33. A method as in claim 31, wherein the guide member is tensioned by inserting a wire core through an axial lumen of the guide member and engaging a distal end of the core against a distal end of the guide member.

34. A method as in claim 33, further comprising withdrawing the catheter from the guide member while maintaining the guide member under tension and thereafter introducing a second catheter having a larger cross-sectional area over the guide member while maintaining the guide member under tension, whereby the size of the passage may be increased.

35. A method as in claim 31, wherein the hollow body organ is the gallbladder and the passage includes the cystic duct and the common bile duct.

36. A method as in claim 21, wherein the guide member is flexible and the proximal end is pulled with sufficient force to inhibit buckling and misalignment of the guide member while the dilation member is being advanced.

37. A method as in claim 21, wherein the guide member is rigid and the proximal end is pulled with sufficient force to inhibit deformation or detachment of a wall of the body cavity from the surround fascia as a result of advancing the dilation member.

38. A method as in claim 25, wherein the guide member is flexible and the anchor is drawn with sufficient force to inhibit buckling and misalignment of the guide member while the dilation member is being advanced.

39. A method as in claim 25, wherein the guide member is rigid and the anchor is drawn with sufficient force to inhibit deformation or detachment of a wall of the body cavity from the surround fascia as a result of advancing the dilation member.

40. A method as in claim 20, wherein the dilation member is sized sufficiently large to form a penetration diameter in the range from 10F to 30F.

41. A method as in claim 20, wherein the dilation member is in contact with the tissue as the dilation member is advanced.

42. A method as in claim 20, wherein the dilation member has a tapered distal end to facilitate advancement.

43. A method as in claim 24, wherein the dilation member sized sufficiently large to form a penetration diameter in the range from 10F to 30F.

44. A method as in claim 24, wherein the dilation member has a tapered distal end to facilitate advancement.

45. A method as in claim 24, wherein the dilation member is in contact with the tissue as the dilation member is advanced.