3'7~
CATHETER- STYLET ASSEMBLY
FOR SI,IPOvrR~ R~L INSTRU~ENTS
Back round of the Invention _ q~
The present invention relates ganerally to instrumen-ts for dilating a body passage to enahle draining a fluid through the passage; and, in particular, *o tubular instruments adapted to pass through the urethra to the urinary bladder for (1) dilating a narrowed urethra,
(2) wil:hdrawing urine, (3) inserting urethral instruments including retention catheters into the urinary tract or (4) performing urologic suryery.
The present invention specifically relates to a rigid, hollo~ stylet for insertion within a flexible, hollvw catheter having an open tip portion -~ the stylet cooperates with a filiform to place the catheter in the bladder.
The stylet can also be used without the filiform ~or placement of ~atheters that do not have open tip portions.
~, l~y way of backgro~nd, th~ BiZ~2 of most urologic ln~tru~ent~ including c:~th~3ter~, Eili0r7n~, follower~;, bougies And 30und~ 1B de~ermined by the outer diamete~ of the ~nstrumen'c. Al'ch~gh th~re ~a:e both Anerican ~nd Engli~h 3c2l1e~3 of mea~uxement, ~he Charriere or French tF ) 8cale i8 ~IOEI'C requently u~ed.
~ccording to ~he Frerlch scale, the 3ize of a tubular instrument is deternnined by multlply~ng th~ diameter expre~sed in mlllimeters (mm) by 31~ Thus, ~ di~mRter o~ 8 nun i-~ e~uai to No. 24 F.
Ca'cheters, afi deJ~ined h~rein, are hollow, tubular instxulo2nt~ ~ade of rub~rr Iylo~ illeone, T~ElonT~M ~oven ~ilk t~ti~fened by ~h~llac~, pla3ti~ or metal th~ are u~ed for drainage o~ ~lui~l ~@dlia, ~pecifically urine, from the blaslder. Msny dif~eren types ~re available from a ~tra.ight ~ube for ~ ~In~le ln~ertion to tu~es ~f varyin~ sh2lp~ c:urves and dl-am~ter~ ~or 8pecifit: situations. All ~athet~rs" how~
ever, have ~im~l~r r'unction~ -- to provlde draina~ge, 'co intr~duce ~Redications and r~dio~taue conta~ edia"
and to obtain urine ~pecimen.
Catheter~ may be nonret~tl~te or retentive~
~he most Prequently used ~;traight, ~onret~n~ive ~ath-eters are! ~h~ ohin~on and the whlstl~-tip design ~hich are u~ual.Ly maae of natur~ r 1 ~tex rubb~r.
~he Robin~on c~:theter ha~ a 801ia rounded tip and m~y h~ve twot our or ~ix eyes or hol~ ~long ltB ~3ide.
The whi~tle tip c~theter hss an open t~p port~orl and 'cwo eyes, on~ on the side and on~ the ~emIrounded sn~le o~ th~ t~p. Rol:~in~;on cathelk~r~ h~ the di~d-Y~nt~ge o~ be~n~ norlre~entive but ar~ used ~or a ~lngle insertior~ such a~ in the co~l~c ~on o a urine ~pecimen or in re}le~ring the pat~nt of a~ute ~ladder retent ion.
Another type of nonr~ts~lltive urethral cath-- , s~
eter is the Coude catheter, al80 known a~; the "elbow"
or "natural curve" catheter. The term ~Coude~, o~
course, refers only to the curve of the catheter tip, that tip usually includes a single eye ~nd may taper 5 to a point or have an olive-~haped enlargement (ol$ve tlp~. The advantage oE this curve i8 'chat it can ollow the contour of the bulbar and prosta~ic urethra a~ it curvPs beneath the symphysis pubis and rides over the bladder neck~ Coude catheters are u~ually 10 made of red rubber, are somewhat ~tlff~r than Robin30n catheter~ and are of ten inpregnated with sm~ mounts of lead for radiographic observation.
The most frequently us~d retentive cath~ter for draining the bladder i5 the ~oley type, w~ich 15 comprises two . tubes -- a larger tube for drainage and a smaller ciae tube connected to ~ balloon that is inflated with a fluid after the c~theter i~ positioned.
The inflated balloon thus prevents the catheter from slipping out. A Councill catheter i8 ~imilar to a 20 ~oley catheterr but includes an open tip portlon that receives a ~pecial stylet which ~an be threada~ly connected to a filiform. The tip of the Foley and Councill catheter usually includes one or two eyes between the tip and the balloon. The present inven-25 ~ion relates to an improved Councill catheter-stylet com3~ination in which the filiform and stylet are not threadably connected.
A
catheter can usually be lpassed through the urethra 30 without incident, S: ccasionally, however, particularly ~hen the lumen of 'che urethra i8 n~rrow~d because of disease or when a large tube such ~ a cy~toscope or a large -catheter i8 to be pa~sed, the urethra may have to be dilated. This i~ done by in~erting and 35 ` withdrawing a ~erie~ of progressively l~rger dila~ion in~ trume nt ~ ~ di 1 ators ) .
~L~
The most common dilator i~ a ~olid smooth metal instrument with a curved tip, ~alled a sound, that looks like ~ metal catheter. ~or ex~mple, the Van Buren sound is such a solid metAl instrument but it is not intended to be l~ft indw~llingO
A bougie can also be used. A bougie is a slender, flexibl~, cylindrical ~olid instrument hav-ing an enlarged tip portion for introduction into the ur~thra or other tubular organ, usually for the pur-pose of calibrating and dilatin~ a con~tricted area~
If the passage i~ ~everely con~tricted, useo a filifonm and a follower may be necesqary. A
filiform is a narrow, solid, somewhat stif instrument commonly used to traverse a strictured urethra. Var-ious filiform tips can be used, such a~ a straight,~piral or olive tip. The en~ of the filiform opposite the tip includes a female threaded porti~n. The fol-lower, a semi-flexible c~theter or bougie with a male threaded tip, is then threadably conne~t~d to the ~0 threaded portion of the Piliform to define a tapered as~embly having the appearance of a flexible whip.
The as~embly can be guided through the strictured area and followers of an inere~ing diam~
eter can be ~ttached to the filiform upon withdrawal of the follower rom the urethra to ~u~ther dilate the ~tricture. A8 the follower i8 lntroduced, the fili~orm mexely coils on it~elf in~id~ the bladder.
The ~crew-on filiform may have either a male or fe-~ale thr~ad and~ of course, the follower must have a corresponding thread to be of use. Prequently the assembly mu.Rt be left indwelling, p~rticulaxly when it i~ desirable to dilate the urethra gradually over the co~r4e of several days. In that ca~e, since t~e ~iliform is a solid ~haft, eyes are provided in the sid2~ of ~he ratheter follower at th~ tip end portion to pexmit the dr~inage of urine from the bl~dder~
In a ~imilar manner, a flllfonm can be threadably connect~d to a ~olid metal 3tylet for pa~-~age through the urethra. The -~tylet c~n be used to paR~ a catheter through a ~trictured urethr~. In S prac~ice, the ~olid stylet ls in~arted within the catheter ~o that the threaded tip of th~ stylet ex-tends beyond the open tip portion of the ~atheter, and the stylet can be threadably connect~d to the iliform. The fillform, stylet and eatheter are then pas~ed through the urethra to the bladder~ Once the tip of the cathet~x is in ~he bl~dder, a balloon or an inflatable portion near the tip c~n b~ ~n~lated to secure the catheter in position. Thereafter the filiform-~tylet a~embly is withdrawn.
Probl~ms frequently arise, however, in the use of a thread~d filiform-follower (or iliform-sty-let) assembly. For example, the threaded connection can break or the follower tor the ~tylet) CaD sepa-rate from the filiform after in~ertlon. In that case~ it is ~ery difficult to extri~ate the filiform from the bladder. Such removal can be perfon~ed endo copically, or ~urgery may be re~uired to open the bladder ~nd gain sufficient ac~e~ ~or removal.
In addition ~o thi~ serious disadv~ntage, the cur-rently used thre~ded a$~embly i8 nondi~posable and mu~t be sterilized after each use. Moreover, the operation of connecting the threaded portion cf th~
~iliform and ~he ~ollower or the stylet i~ awk~ard and time consuming.
3~ ~
In addition to the previou~ly de~cribed urol~gic instrumentsr ~he following references con-stitute the closest prior art of which ~pplicant is aware.
~.S. P~tent No. 2,856,934 to Petillo rela~es to ~ cath~ter consi~ting of a ~olid, flexible filiform and hollow, rigid follower. That reerence does no~
show a hollow filiform or a hollow ~tylet for ureth ral catheter insertion. Moreover, the solid filiform of Petillo increases in diameter along it~ length such that at mid-length, the filiform mea~ures 6 F.
Since the hollow, rigid follower will only accomm-odate a filiform measuring 5 F or le~s~ the ~omplete length of the Rolld filiform cannot freely pa58 through the follower and the follower ~annot pa~s all the way over the filiform.. A~cordiny to the present invention, a holl~w filiform has a uniform diameter throughout its length to permi~ urethral instruments to slidably pass oYer the filiform for intxoduction into or removal from the urethra while the filiform remains positioned within the urinary tract~ Thi~
enables an interchangeability of urologic~l instru-ment not suggested by Petillo. ~l~o, the filiform can be removed to leave the retention catheter in the bladder.
U.S. Patent No. 3,811,449 to Gr~vlee et al.
di~closes a dil~ting apparatus which permit~ the in-sertion of a medical instrument into a body pa~sage while the opening to the passage i3 ~aintained in a dilated state larger than the diameter of the instru-me~t. ~n elongated, solid flexible probe h~ving a uniform diameter and ~ rounded in~erticn tip i~ in-~erted into the passage. A first elongated, flexible, hollow dilator is in erted over the probe up to the insertion tip of the probe. The solid probe is then removed and a second elon~ated, flexible hollow dila-tor having a slightly larger internal diameter than the.external diameter of the first dil~tor is inserted co extensive over the first dilatorO In thi~ m~nner, dil~tors having a successively greater internal di-s~
-- 7 ~
ameter are se~uentially lnserted ov~r dilator~ of lesser diameter and the smaller, lnncr ~ilator~ ~r~
removed from the passage until the ti~ue ~ stretched to a predetermined size by a final dilator~
Th~ Gravlee device, however, i~ de~Lgned or use in dilating the cervical can~l. Although GraYlee et al. mention the use of the probe and di-lators to enlar~e the urinary tract~ that device is not uitable for urethral insertion ~nd fox use with urethral instruments ~uch as a catheter, cystoscope or urethrotome. ~irst, the probe i~ ~olid rather than hollow; and the external and internal diameters of the probe are large relative to the filiform of the present invention. Second, the le~ding ends of the probe and th,e dilator are not tapered or narrow enough to serve a~ a guide through the ~trictured urethra.
Aocording to the present invention, it is essential that the filiform be small or narrow enough to pass within a cathet~r ~uch as a Couacill catheter, and its stylet. Moreover, the filiform mu~t be narrow ~nd have a tapered or rounded tip to prevent injury to the urethral mucosa during passage. use of an extxemely narrow filifonm as a guide maintain~ the continuity of the urethra when catheters are changed after the damaged urethra has been ~urgically repaired.
Summary Of The Invention The pre~ent invention relates to the use of elongated filiforms or guides with ~lipover instru-ment~ and, in parti~ular, to an improved catheter-~tylet combinatio~. One embodiment of my device compri-Res an elongated hollow filiform which is pa~sed through the urethra to probe, seek and follow ~he pa~sage. If the urethra is p~rticu-larly difficult to traverse~ a metal wir~, al~o called a stylet, can be inserted within th~ filiform to increase the ~tiffnes~ of the fillfoKm during placement. Thereafter, the operator can insert a hollow dilator over the filiform while the ~iliform remalns within the urethra.
The filiform ~erves as a guide for the subsequent insertion of instrument having various diameters into the urinary tract to dilate or cali-brate the urethra. Indeed, the filiform can be used with most followers and sounds provided that the di-lators are hollow through ~heir len~th to form an opening slightly larger than ~he outer diameter of the filiform at the distal and proximal end~ thereof.
The hollow filiform al~o helps prevent ~al-~e pa~sages and the curling ~f the filiform in the urethra by permitting the operator to remove the wire ~tylet from the filifoxm and check for drainage of urine so that the operator will note when ~he tip of the fili-form i~ in the bladder.
The pre~e~t invention also involves an improved catheter-stylet for use with the above-described fillform. The stylet i5 paxticularly ~uited for use ~n the described slipover conceptO
Specifically, the elongated, hollow ~
form having a tapered insertion tip iP passed through the urethra to the urinary bladder and functions both as a probe to seek ~he lumen or openlng o the urethra and as a guide so that a rigid, hollow stylet within a Councill catheter or the like can be slidably passed over the filiform while th~ filiform remaîns in a stationary pvsition in the urethra and bladder.
The stylet and the filiform can then be removed to lea~e the catheter within the bl~dder. If the urethra is severely constricted, a flr3t elo~gated, hollow dilator can be guided over th~ filiform to _ 9 _ dila~e or widen the urethra before the ~tylet and catheter can be replaced by a second dilator having larger outer diameter to further dilate the urethra without removal of the filiform from the pas~age.
It follows, therefore, that it i8 an object of this invention to provide a device for passage to the bladder through the urethxa wh~rein the device can be assembled in a simple and ~fficient manner and disengaged for separation of one part from the other for easy removal without the danger of breakage. The egress or aspiration of urine through the filiform indicates the location of the filiform tip within the bladder. False passages and curling of the filifonm can be prevented because the operator can determine when the filiform tip enters the bladder. Moreov~r, the slipover concept permit~ a more orderly interac-tion between urologic instruments.
It i~ a related object to provide a hollow stylet for use in combination wlth the filiform and a hollow catheter having an op~n tlp portion such as a Councill c~theter wherein easy ~cce~s can be had for assembly of the parts in a simple and efficient manner. The ~tylet ~an also be u~ed without the filiform for placement of cathet~rs that do not have open tip portions including Fol~y catheter~.
The~e and other object~ and advantages o~
this invention will hereinafter appeax and for pupo~eq of illustr~tion, but not of ll~itation~ in the accom-panying drawings.
Brief Descri tion Of Th~ Invention ._ P , ~
Figure 1 i5 a side view of a ~lexible cath-eter passed coaxially over the ~tylet and a hollow fili~orm;
Figure 2 is a side view of the ~tylet;
Figure 3 is a cross-~ectional Yiew taken ~lon9 the line 3-3 of Figure l;
E'igure 4 is ~ schematic view shcwiny a hol-low filifG~m havin~ a tapered tip pa~sed through the urethra into the bladder;
Figure 5 is a schematic view %howing the catheter and stylet slidably passed over the fili-form; and Figure 6 is a schematlc vi~w showing the filiform member and stylet wi~hdrawn, 1eaving a Coun-cill catheter in position to drain the bl~dder.
Detailed Descrip~ion Of The Inv ntion . _~
The present inve~tion relateR to the use of an elongated, hollow filiform as a guide for a cathe-ter-stylet assembly. The invention replace~ standard filiform and catheter stylets now available which usa a threaded locksng mechanism to connect the Pilifonm to ~he s~ylet.
Ref~rring to Figure 1, the device include a filiform 10 in the form of an elongated, hollow, f1exible member having a relatively small cross ~ec-tion with a rounded or tapered end portion 12 on it~proximal end 14 to facilitate in~ertion through the urethra 16 (see Figure 4) and to avoid ~harp edges which might traumati2e the ti~sue o the urethra.
~he filiform 10 can be made into a variety of types, ~uch as a straight member of unifonm cro~s -~ection or the proximal end 14 can be in the orm of a ~piral tip, an olive tip or the like. Th~ filiform is di-mensioned to have a length consider~bly greater than the distance between the bladder 18 and the external opening of the urethra.
In one embodiment, the filiform ~ 27 inches long and 4 F in diameter. Because o this small di-ame~er; the filiform can be u~ed to pa ~ through the urethra and into the bladder. As indicated, the filiform is hollow and can be con~idexed a iliform catheter since an opening 20 prnvld~ a p~u~ag~ for the drainage of f luid, ~uch a~ urine rom the bl~dder, and the in jec~ion of a radiopE~Que medium to determine the position of the filiform in the urin~ry tract.
5 ~n additlon, a metal wire or stylet 22 can be in-~erted withln the filifo~ to ~rovide the nec:~s~ary stiffnes~ ~nd tactile ~en~ation ~or p~age of he hollow fil~foxm through the urethrR.
The pre~ent device ~l~o include~ ~ atylet 10 24 and a catheter 26 in the form of elonga~ed, hollow members, each having a pa~age 28 ~nd 30, re~pectively~
extending continuously therethrough. Ax used herein, the term l'wire stylet" refers to the tylet 22 that pa~ses within the filiform lû. The term ~stylet~, on 15 the other ha~n~i, refers ts:~ the ~tylet 24 tha'c ~8 ~ub-~tantiall5~ larger in cross-~ectlon than the stylet 22 nd which passe3 within the c~theter 2S~
Re~erring to ~igure 2, the stylet 24 i~
preferably made of a corrosion r~sistarlt metal alnd 20 has a curved and tapered proximal end portiorl 32 for insertion through the cathetar. An ~nnular projec-tion or bulbou3 portion 34 about the proxlm~l end portion 32 expand~ the elastic inner w~ll of the catheter 26 ~o hold the ~tyl~t 24 within the 25 catheter.
The distal end 36 of tbe ~tylet 24 includes a gripping portion 3B that i~ enlarged relati~re to the shaft 40 of the stylet. The gripping portion 38 i~ in th~ ieorm of a cylinder with a flat ~urface 42 30 and a rounded surface 44 for holding by the thumb and ~oref inger of the user. Between the ~ha t 40 and the s~ripping portion 38 is a barrel-~haped portion 4~ _ having a diameter slightly less th~n the inner di~
elter of the catlleter to allow the dista~l end 48 of 35 'che catheter to re3t cver tlle barr~ àaped portion 7~ j~
46 and against the gripping portion 38. Annular rings 50 about the barrel-shaped portion assist in holding the distal end of the catheter in a fixed position on the stylet.
It can be ~een that the gripping portion also functions as a means for preventing the pxoximal end portion 32 of the ~tylet 24 from pa~sing ~eyond the proximal end portion 52 of the c~theter 26; and that the length of the ~haft is approximately equal to the length of the catheter.
The catheter 26 has an opening in the prox-imal end portion 52 and includes a~ least one opening 54 through the side wall of the proximal end 52 to enable urine to drain from the bladder into the cath-eter. ~he catheter, like the ~tylet 24, is dimen-~
sioned to have a length slightly greater than the distance between the bladder and tha entrance to the urethxa but less than the length of the filifvrm 10.
The proximal end 52 of the catheter c~n be formed to extend at an an~le from the body portion 56~ like a Coude catheter to facilitate insertion through the urethra; or the catheter can comprise a stralght semi~flexible memberO
In conventional practice, the catheter is generally made available in various cross-se~tional di~ensions to permit utili2ation of the maximum ~ize catheter in the event that the passage through the urethra is very tight and to enable u e of ~theters of increasing cross ~ection for replacement of one with another over a period of ~ime a5 the obstruction through the urethra is relievedO
. As de~cribed, the stylet 24 ~an be foxmed of a çorrosion resistant, inert met~l of the type used for surgical in~truments to enabl@ repeated uYe with sterili~atlon procedures after a~ch u~e. It is r~
preferred to fonm the filiform of a plastic material as a ~ingle use, aseptic, dispo~abl~ item.
An important concept of the ~nvention re-sides in the ability of the hollow stylet 24 to freely ~lide over the filiform through the urethra and provide for removal of the filiform and the stylet while the catheter 2~ remains in the pas~age.
Equally important is the ability of the ~tylet 24 to move within the catheter 26. But the stylet tip cannot pass beyond the tip of the catheter and the catheter-stylet assembly must function as a unit during insertion with the stylet ~ecurely holding the catheter thereon. The interaction of these co~pon-ents can be more clearly seen in Figure 3.
In use, the hollow filiform 10 i directed through the urethra until the tapered end portion 12 enters the bladder, as shown in Figure 4. The filL-form may coil on itself upon entering the bladder, and entry into the bla~der is u~ually indi~ated by the egress or aspiration of urine through the fi~i-form. If the urethra is particularly di~ficult to traverse, the wire stylet 22 can be in erted withio the fili~orm to increase the stlffne~s of the fili-fohm during pl~cement.
Next, ~he stylet 24, which has be~n in~erted within the catheter 26 is slidably pa~e~ ~oaxially over the filiform and into the urethraO
~he hollow filiform 10 Q~ the pre~ent in-vention offers ~everal advantages and safety features over the solid iliforms of ~he prior ~rt. Por ex-ample, by ob~erving the egress of uri~e from the filifonm catheter once the wire Atylet 22 i~ removed, one can ~afely conclude that the filifor~ tip i~
properly positioned in the bladder and th~ filiform is not in a fal~e passage.
If the volume of effluen'c ln in~u~ficien'c, urine can be aspirated through the ~ orm ~th syringe. Moreover, a radiograph car~ be t~lcen to determine the position of the filiform tip by inj~c-ting a radiopaque contrast medium thro~gh the fili-form. That was not po~ible with th~ 11iforms of the prior art.
In the event that the stylet 24 and cath-eter cannot be advanced over the filifonm for passage through the urethra, a hollow dil~tor of smaller ~ross section can be substituted. Once penetratio~
has been establi~hed and the pass~ge through the ure~
thra is dilated the stylet and catheter can be ~ub-~tituted by xemoving the dilator without removal of the filiform and by pas~ing the catheter-stylet a sembly over the filifonm and through the ur~thra into the bladder (see Pigure 4).
Therefore, the operation of inserting an indwelling catheter (such ~ a Counclll ~atheter~ in-volves (1) in~erting a filifonm c~theter 10 through the urethra into the bladder, ~2) dilating the ux~thra as necessary, ( 3 ) removing the dilator u~ed and leav-ing the fillform in place, (4) in~erting the ~tylet 24 into an open tip catheter, (5) ~lippi~g the cathe-ter-stylet asse~bly over the filiform 1~ into the b~adder, (S) inflating a balloon 58 ~see ~igure 6) of the catheter thrsugh a side port 60 (See Figur2 1) and ~ 7 ) removing the f ili~orm and the ~tylet. It will be noted that th~ balloon 58 i8 inflated in a conventional manner by in~ectiDg ~ fluid into the ~ide port 60 once the proxlmal end portion 52 of the ~atheter is within the bladder. ~he fluid pas~e~ _ through a condu~ t 62 ~Figure 3 ~ within he catheter to inflate the balloc3n.
Many other urologic i n~trunent~ th~t ~re - 15 ~
currently available can al~o be u8ed with thl~ device and method without modification. Fox example, a ~ys-toscope w.ith a direct ~ision obturator ln place ~nd without the lens will ea~ily slip over the filiform.
~ cystoscope i~ an instrument ~pecific~lly de~igned for passing through the urethra into the bladder to permit inspection of the interior o that organ. At the end of the cy~toscope is an electric bulb or a fib~roptic lens sy~tem that illuminates the bladder interior, and a channel is provided to pa~s an irri-gating fluid to distend the bladder. By mean~ of special lenses the bladder mucosa can be examined for inflammation, calculi or tumors. A ureteral ~atheter can then be pas3ed through the cy~to~cope into the lS bladder and beyqnd the bladder into th~ ureters and kidneys. In this manner, sample~ of urin~ can be obtained for di~gno~tic purposes or radiopaque fluid8 can be injected into the uretera for X-rays of the upper urinary tract.
In addition, the perform~nce of urologic ~urgery can be facilitated by use of the pres~nt in-vention. It should be pointed out that most urethral strictures are succe~fully treatsd by gxaduAl ureth-ral dilaticn using filiforms ~nd follower~ or sounds ?5 of increasing ~ize. OccasionalLy, how~vert very tight strictures of a fibrous nature re~uire trans-urethral inci~ion. For this purpose a urethrotome, whi~h compri~e~ a metal in~trument having a ~mall knife blade hidden within it~ tip, i~ frequently ~0 u~ed. The blade can be advanced or w~thdrawn and ~
the blade i~ manipulated, the roof o~ the urethra i8 incised. Following the division of the stricture, a retention catheter is introduced. The device of the pre~ent invention enables the urethrotome to be in~
serted over the hollow fi1iform ~nd ~ubs~quently when the urethrotome i~ removed, the ~ orm will rem~n a~ a guide to pl~ce the 3tylet and Counclll catheter assembly without losing the cour~e of the urethra.
It will b2 apparent from the foregoing that a considerable improvement is provlded in the ease and safety of passing the catheter and the ~tyle~
over a filiform as compared to the awkward and poten-tially dangerous procedure of threadably connecting the filiform to the stylet. In ~ddit~on, placement of the elongated filiform allow~ dilatation by a hollow pla~tic follower or~a hollow ~etal sound, cy~toscopic examination, direct view urethrotomy ~nd the subsequent placement of a Councill ~atheter or the like.
It will be understocd that changes may be made in the details of construction, arrangement ~nd operation, without depar~ing rom the spirit o th~
present inven~ion, especially as de~ined in the fol~
lowing claims.