CA1183748A - Percutaneous implant - Google Patents

Abstract

PERCUTANEOUS IMPLANT
Abstract An implantable device for providing communication between interior structures of the body and the exterior of the body, the device comprising a rigid tubular member of biologically compatible material including a transcutaneous stem portion defining a stem cavity therein and having a smooth exterior, and a flangeless subcutaneous portion in fluid communication with the stem portion. A flexible peritoneal catheter is connected to the subcutaneous portion. A septum closure in the stem cavity provided to give an interruptable seal between the stem cavity and the catheter. The subcutaneous portion includes a Dacronm brand polyethylene terephthalate velour collar on the exterior surfaces as a tissue ingrowth media.

Description

~3~

PERCUTANEOUS IMPLANT
I. DESCRIPTION
Background of the Invention The present application is directed to implanted devices for pro~iding communication between internal structures of the body and the exterior of the hody. In particular, the application is directed to implantable structures for peritoneal dialysis applications.
Peritoneal dialy~is is a process whereby dialysate solution is introduced into the peri-toneal cavity for a pe~iod of time during which waste materials pass from the blood t~rough the peritoneal membrane into the dialysate. The wastes are removed ~rom the body by draina~e of the dialysate from the peritoneal cavity.
Peritoneal dialysis may be performed intermittently by machines which automatically fill and drain the peritoneal cavity, usually while the patient is sleeping. Another variation of the process, "continuous ambulatory peritoneal dialysis" (CAPD), has shown increasing use in recent years because, among other reasons, of its relatively low cost and ease of patlent self-care and c-omparison to the more typical hemodialysis treatment. CAPI) also allows a patient to enga~e in most normal life activities while undergoing dialysi~. A.q typically practiced, CAPD utilizes a perforated catheter of a silicon elastomeric material, such as medical grade Dow 5ILASTIC~ brand material, implanted in the peritoneal cavity and expanding through the abdominal wall. Sterile dialysate is infused into the peritoneal ca~ity hy conrlecting ~he catheter to a container of dialysate and raisin~ -the container above the abdomen so as to the drain the contents into the peritoneal cavity.
Prepac~aged flexible plastic bags of dialysate offer the advantages that drainage may be accomplis'hed without venting to the atmosphere and that the bag, when empty, may be left connected to the catheter and strapped around the patient's body duri~g residence of the dialysate ~n the ~/r~

solution. After several hours, the ba~ i5 lowered below the abdomen, and the used dialysate fluid permittecl to drain back into the ba~. The catheter i9 then connected to a fresh dialysate container whlch is infused as described into the patient.
In spite of its obvious advanta~es/ CAPD suffers erom serious problems because o a frequent occurrence of peritonitis caused hy bacterial infection in the peritonium. These infections are most typically caused by non-sterile technique in connectin~ the catheter to dialysate containers.
Infections may also occur at the exit site where bacteria may invade the body alon~ the exit openin~.
Subcu aneous cufs of Dacron~ brand polyethylene terephthalate felt, as sold by E. I. Dupont, adhesively joined to the catheter below the skin, have been used to provide tissue in~rowth media so as to anchor the tubes and provide a scar tissue harrier to bacterial penetration;
but, exit site infections remain a si~niEicant problem.
This may be related to the flexible nature of the catheter at the exit site, the movement of which may facilitate bacterial penetration. Additionally, dimensional chan~es :in the silicon catheter due to uptake of body fluids or ~radual de~radation thereof by body fluids may also contribute to the exit site infection problem.
A variety of implantable percutaneous devices have been described for providin~ external access to internal structures of the body, primarily of the circulatory system. Such structures typically embody flan~e means for anchorin~ the device below the skin layer.
Porous tissue in~rowth media, such as velour cloth or Dacron~ brand polyethylene terephthalate felt have also been used with such devices to add to the anchorin~ ability of the subcutaneous flan~e members. As described in U. S.
Patent Number 3,7~3,86~, however, such flan~ed devices exhibit a problem in that epithelium tissue pro~ressively - 3 ~

~rows down and around the device, eventually encapsulat.ing it and expellin~ it ~rom the hody.
Brief Description of the Invention .. ... ...
In p.revi.ous patent applications, the applicant has described a T-shaped percutaneous device for providing access to the circulatory system. l~e device is coated with a porous tissue in~rowth media, such as Dacron~ brand polyethyLene terephthalate velour or matte titanium. ~hen implanted, the devlce becomes securely anchored to the body by tissue in~rowth into the porous material, without the need for a subcutaneous stab~lizing flange. The stem of the T extends through the skin layer and is sealed by septum means within the stem through which access may be had to the circulatory system. This device does not have a tendency to be encapsulated by epitheleum tissue and expelled from the body.
It is an object of the present invention to provide a permanently implantable percutaneous device particularly suitable for peri.toneal dialysis application on a continuous or intermittent basis. Structures of the present invention have improved characteristics for preventing the introduction of bacleria during dialysate changes and for preventing exit s~te infections.
In accordance with the present invention, there is provided an implantable device for providing communication between interior structures of the body and the exterior of the body, the aevice comprising a ri~id tubular member of biolo~ically compatible material including a transcutaneous stem port.ion defining a ~tem cavity therein and having a smooth exterior; and, a flangeless subcutaneous portion in fluid communication with the stem portion and attached to a peritoneal catheker.
An embodiment especially useful :Eor intermittent peritoneal dialysis employs a pair of arms as the suhcutaneous portion of the device, each of which are connected to a separate perforated catheter placed in different l.ocations ln the peritoneal cavity. A septum closure in the stem cavity pxovides an interruptable seal between the stem cavity and each o the arms. By using a dual needle assembly to access both arms throu~h the septum, fresh dia]ysate may be simultaneously pumped into the upper peritoneum while used dialysate is drained from the lower peritoneum.
The subcutaneous ~xterior portion of the device contains, on at least a part of the exterior surfaces 10 thereof, a porous ti.ssue ingrowth media such as a collar of Dacron~ brand polyethylene terephthalate velour or a coatin~ o porous titanium.
The percutaneous devices described herein as useful for peritoneal dialysis applications have a lon~er useful life with reduced .risk of e~it site infection over conventional silicone elastomer catheter implants.
Furthermore, structures of the present invention, which include a septum closure within the tubular body, have the added advantage that the r.i~k of peritonitis is reduced 0 because an added bacterial barrier is provided.
Brief Descript n of the Dra~
The fi~ures are found as follows:
Sheet 1 - Fi~ures 1, 7, and 8; Sheet 2 - Fi~ures

2, 3, 4, 5 and 6, Sheet 3 - Fi~ures 9, 10, 11, 12 and 13, Sheet 4 - Figure 14~
Fi~ure 1 is an e~ploded pictorial view of a T-shaped device for use in blood access applications including t~e implantable portion, a two needle cooperating member and a modified forceps or use in assembly and 30 dlsassembly of the .implanted septum assembly.
Figure 2 is a top plan view of the implantable T-shaped assembly.
Figure 3 is a side elevational view partly in section as taken along the lines 3-3 of Figure 2.
Figure 4 is a plan view top side of the septum.
Fi~ure 5 is a section view alon~ lines 5-5 of _5~ 37~

Fi~ure 4.
Fi~ure 6 is a plan view of the bo-ttom or interior Eacin~ side of the sep-tum~
Fi~ure 7 is a sectional view of a device in accordance with the invention with the cooperatin~ needle assembly in operative en~a~ement ~ith the implan~able portion.
Fi~ure 8 is a side elevational view partly in section of the T-shaped implantable structure and cover assembly.
Fi~ure 9 is a -top plan view of a preferred septum structure.
Fi~ure 10 is a slde section view of the preferred septum taken alon~ line 10-10 of Fi3ure 9.
Fi~ure 11 is a pictorial view of an alternate structure of the present invention with peritoneal dialysis catheter attached.
Fi~ure 12 is a side sectional view of the device of Figure 11.
Fi~ure 13 is a front plan view of an alternate peritoneal dialysis structure with a cooperatin~ needle assembly.
Fi~ure ]4 is a front plan view of another alternate perito~eal dialysis struc-ture with a cooperatin~ 5 needle assembly, which is the subject of this application.
De~ailed Description of the Invention ____ _ ~_ Blood Access Embodiment Referrin~ to the drawin~s, there will be seen in Fi~ure 1 a device in accordance with the invention which includes a T-shaped unitary tubular body ~enerally desi~nated 10 havin~ a stem portion 11 and a strai~ht tube portion 12. Body 10 is formed of a unitary body of a biologically compatible material such as titanium. It is hi~hly advanta~eous that body 10 be of a unitary construction to eliminate extraneous cavities at points of assembly of non-unitary bodies. At least the external 1. ~

- 6 ~ ~37~

surfaces oE body 10 may be coated with a continuous layer oE pyrolytic carbon to enhance biocompatabllity. This is particularly of importance for surfaces -that will be blood contactin~ surfaces, such as the bore when blood i5 at flow therethrou~h. Pyrolytic carbon coatin~s are known to be biolo~ically compatible materials and have been used in implanted structures. See, or example, U. S. Pa-tent Mumber 3,783,868. Alternatively, the body 10 may be uncoated titanium or other ri3id material. As illustrated in Fi~ure 7, a snu~ly fittin~ slee~e member 34 of ~raphite may be used to line the interior of tube 12 and underlies coatin3 13. For coatin~ the interior of a tube, it has been found desirable to have the ~raphite sleeve to serve as a substrate for the pyrolytic carbon.
Expanded polytetrafluorethylene tubes 14 are shown joined to ends of 12 by slippin~ over these ends.
Dacron~ brand polyethylene terephthalates or other body compatible polymeric materials may be used rather than polytetrafluorethylene. The e~panded polytetrafluorethylene slipped over the ends of 12 may be provided as an intermediary for join;n~ blood vessels to the assembly 10. A TeElon~ brand polytetrafluorethylene shrink band 57 aids in holdin~ the sleeve on.
Alternatively, tubes 14 may be attached by nonabsorbable sutures. A suitable expanded polytetrafluorethylene is sold under the trade name Gore-Tex~ by W. L. Gore Company of Newark, Delaware. It should be understood that tubes 14 are elective in that it is not necessary that they be present.
Alternatively, an uncoated device 10 may be directly placed in a blood vessel. In such a case, the blood vessel would be slit lon~itudinally for a sufficient distance for the device 10 to be inserted and the vessel drawn around the device and sutured into place. A collar member 29, as described below, would be used around a portion oE -the stem to aid in tissue in~rowth to the stem ;i ~!.

portion.
As can best be seen in Fi~ures 3 and 7, body 10 is formed wlth an internal extension 15 which suhstantially provides a separation of the internal stem cavity 30 of T~
shaped membex 11 from the tubular chamber of portion 12, except Eor the openin~s 16 and 17. Member 15 provides a support surface Eor a septum member 18. Member 18 is formed of an elastomer, such as natural rubber, and, as can be seen in Fi~ures 2, 4, 5 and 6, has a broadly elliptical confi~uration. The purpose of this shape is best under-stood with re~erence to Fi~ure 2.
In Fi~ure 2, there is seen a top view of s-tem 11. As can be seen, stem 11 has a ~enerally round openin~.
There is provided an internal shape in the openin~ alon~
the axis of tube 12 which conforms ~enerally to -the ends 19 of the septum 18 for indexin~ purposes.
As can be seen in Fi~ures 2, 4, 5 ancl 6, septum 18 is pre~cut in a three-directional star or tricuspid form 20. Preferably, althou~h not mandatory, the hole 21 may be completely throu~h septum 18. These cuts facilita-te passa~e of a needle throu~h the sleptum. At the outer surface of the septum 18, there is a counter sunk re~ion 36 for receivin~ a needle. The cuts 20 are posit:ioned so that when member 18 is indexed into the openln~ of T-stem 11, c~ts 20 are centered on openin~s 16 and 17. As a preferred alternative, the needLe openin3 in septum 18 may be actually formed into the septum at the tlme the septum is fabricated. When the septum is pressed into place, the compresslon will seal the openin~s 21.
Overlying septum 18 is a pressure plate 22 of titanium or the like which defines openin~s 23 which are spaced to conform in position to slits 20 and openin~s 16 and 17. Pressure plate 22 is, in turn-, locked into en~a~ement with septum 18 by a sprin~ retainin~ rin~ 24.
Fi~ures 9 and 10 show a peritoneal septum confi~uration. The preEerred septum 48, which is more fully described in co-pendin~ Canadian application serial number 376,S07, filed April 29, 1981, has, as preformed needle openin~s, two slits 49 cut throu3h the septum and extendin~ from near the center of the septum out to the ed~e thereof.
The ed~es of septum 48 have a ~roove 50 therein encirclin~ the entire body thereof. Groove 50 carries an elastomeric rin~ 52 which preferably has an elliptical or circular cross-section. Rin~ 52, which has a smaller inner circumference than that of the septum, services to hold the slit septum to~ether and maintain the slit surfaces to~ether in sealed relationship by applyin~ an inwardly directed radial force on ~eptum 48. The elliptical or circular shape of the rin~ leaves ~aps in the ~roove into w~ich septum material may move as the needle is inserted.
The septum is also preferably provided with an elon~ated bottom recess 54 and a pair of ~enerally semi-spherical top recesses 56 ali~ned with holes 23 in pressure plate 22 when assembled in the device~ stemO
A cap mernber 26 snaps over a flan3ed ed~e 27 as seen in Fi~ure 8 and is held in sealed relationship therewith by a retainin~ rin3 28. The lower flared ed~e 70 of cap 26 will be sp~ced, in use, sli~htly above the skin 25 of the user. Pressure contact with the skin of flared ~5 ed~e 70 is undesirahle as necrosîs may occur. Overall, there is provided a proflle for the exposed external portion of member 10 that is less likely to catch an object, such as clothin~. Cap 26 also provides a means whereby an antiseptic, such as Betadine~ brand iodine polyvinylpyrolidone complex may be included in cavity 30 to maintain the unit sterile between usa~e.
The assembly described above is implantable in the patient by sur~ical techniques that are known and form no part of the invention. It is deslrable to have the amount of the stem protrudin~ above the skin line at a minimum amount compatible with permittin~ a cap mernber ,~

- 9~

seal. Implantation may be in various manners and modes, includin~, but not limited to, the followin~: by anastomosis to 14, i.e. by splicin~ the ends of a blood vessel to opposite ends of assembly 10. Assembly 10 may be positioned into a blood vessel that has been lon~itudinally slit Eor a distance sufficient to perml-t insertion of the device. In this lat-ter case, the blood vessel is sutured about the dev;ce to form a seal and the sleeves 14 are not used.
To aid in accomplishin~ tissue ~rowth onto -the por-tion of the stem 11 below the sXin lines 25, a collar member 29 of porous plastic material, such as polyethylene terephthalate, sold by E. I. Dupont under the trademark Dacron~ brand polye~hylene terephthalate may be used. The portion of s-tem 11 above the dermis re~ion is uncoated to recluce the risk o infection occurrin~ by bacteria makin~
their way down alon~ t~e collar 29. If the external surface of stem 11 is titan;um, the ti-tanium may have a matte surface in the re~ion oE collar 29 and, thus, eliminate need of collar 29.
When access is to be made to the blood system, the cap 26 i9 removed. The interior cavity region 30 thus exposed can be rinsed with appropriate sterilizin~ a~ents that are removed prior to insertion of a needle throu~h openin~s 23, 20 and 16. It is preferred that cavity 30 be filled with and hold a sterilizin~ solution, such as descrihed previously, between usa~e. This sterilizin~
solution can be placed in cavity 30 before closin~ with cap 26 or a hypodermic may be used to lnject the solution

3~ throu~h the cap. Desirably, the needle u.sed to penetrate the septum will have a closed rounded end with one or more openin~s 45, 46 at -the side thereof. A blood sample can be drawn or material such as dru~s inserted throu~h the needle, as desired.
The device described can be implanted into a patient and remain essentially permanently. However, if a ~,~

need arises to replace the septum 18 after prolon~ed use, this can readily be done wlthout need of sur~ical procedures. A modified forceps 31 is machined or ~round to provide tips 32 of a si~e to be positioned into holes or 5 recesses 33 in retainin~ rin~ 24. The rin~ may be withdrawn a]on~ with pressure plate 22 and septum 18 for cleanin~ and/or replacement. Of course, steps should be taken to ~lock the body blood pressure so as to prevent appreciable blood f]ow outwardly throu~h openin~s 16 and 17 lO durin~ the assembly or disassembly.
It is desirable to utilize a cooperatin~
assembly, such as a member 40. Even when a simple needle is on a standard syrin~e, it is desirable that the needle have a rounded end as will be descrihed below. Member 40 is constructed of a cylindrical block of metal 41 throu~h which two hollow needle members 42 and 43 extend in sealed relationship to member 41. These needle members are positioned so as to index with openin~s 23 in pressure plate 22. As can best be seen in Fi~ure 7, the needles 20 have rounded closed ends 44 and each 'have at least one side openin~ 45 and 46, respectively. As shown, the needle is solid (cavityless) 'below the lower ed~e of openin~s 45 and 46. mis construction is hi~'hly advanta~eous. The rounded clos0d end readily passes throu~h septum 18 with a reduced tendency to cut and break pieces of a septum as a result of passa~e therethrou~h over use of a conventional hypodermic needle. The solid lower end avoids the presence of entrapped air. One can also position -the openin~s in the needles 50 -that if blood flow is in the direction shown by arrow 47, the needle openin~ 45 is directional to withdrawal of blood, while openin~ 46 is directional to return of hlood. The top of the needle can be joined to any suitable construction to be connectable to external blood flow tubin~ or other types of apparatus.
An alternate needle assembly structure, as well as other improvements in the blood access embodiment o~ the :~.

present invention, are disclosed in co-pendin3 application serial number 376,507, filed April 29, 1981 and assi~ned to the assi~nee of the present invention.
Peritoneal Dialysis Embodiments Fi3ures 11~14 show alternate embodiments o~ the invention which are especially applicable to peritoneal dialysis applications. Ais with the T~shaped blood access device described previously, the devices of Fi3ures 11-14 comprise a flan3eless tubular body havin~ a smooth upper exterior surface and a lower, subcutaneous surface which carries a layer of porou9 tissue in~rowth media, such as a collar or cuff of Dacronn' brand polyethylene terephthalate velour cloth or felt. The peritoneal dialysis structures will preferab]y include a sep~um seal means within the interior of the tubular body as does the T-shapea blood access device described above.
The device in Fi~ures 11 and 12, ~enerally desi3nated by the numeral 60, :is substantially identical to that of the T-shaped device described above, with the exception that it has an L-sihape in only one subcutaneous connec-tor arm 62. Device 60 includes a stem portion 64 and an interior cavity portion 66 includin~ a septum closure 68 held in place as described above. Septum 68 is modified from that shown in Fi3ures 9 and :L0 in that the needle openin~ slits 71 is centrally located and does not extend to the ed~es of the septum. This confi~uration is desi~ned to accommodate a sin~le needle.
Also, as with the T-shaped device described previously, implant 60 includes a flan~ed upper ed~e 72 which can carry a cap member. A second excutaneous flan~e 74 may also be provided on the outer surface of the device.
Second flan~e 74 provides means whereby the stem may be held by a clampin3 tool durin~ needle insertion or removal or septum chan~e operations.
As shown in Fi3ure 11, the inventive device, as implanted, will include a silicone catheter member 80 ,. .

- 12 ~ 3~

attached to arm 62. 1~e porous Dacron~ brand polyethylene terephthalate collar 82 extends over the joint between catheter 80 and device 60.
As is conventiona] with percutaneous catheter implants, catheter 80 will preferably have a forward, unperforated portion 86 which will be implanted so as to lie in the abdominal tissue between the skin and the peritoneal wall.
The lower portion 88 of catheter 80 is 10 perfora-ted, the perforations be3innin~ about half the len~th below the point where the catheter enters the peritoneal cavity.
Also, as typical with percutaneous catheters, catheter 80 will preferably include a second cuff 90 aclhesively aff:ixed thereto on the unperforated portion, somewhat above the entry point of the catheter into the peritoneal cavi.ty. This second cuff serves -to anchor the catheter a~ainst si~nificant movement about the peritoneal entry point which could cause dama~e to the peritoneal 20 Wal].
Because the structures -for peritoneal dialysis do not carry pressur:ized liquids, as is the case for the blood access embodiment described above, it is not imperative that the septum seal means be employed in the device of the 25 present invention. As with percutaneous silicone catheter implants, the devices of the present invention may simply be capped to keep out bacteria and other contaminants when not in use. A strai~ht tube device 95 of this type is shown in Fi~ure 13 with a cooperatin~ needle structure 98.
Device 95 includes a threaded excutaneous portion 99 onto which cap 100 of the needle assembly g8 may be screwed.
Rather ~ha.n include a septum and retainin~ means within its s-tem, the i.nterior confi~uration of device 95 is tapered to mate with a tapered male Leur portion 102 on the needle assemhly~ The same device as s'nown in Fi~ure 13 may also be equippe~3 with a septum and retainin~ means within its , .

stem.
The use of a septum closure in the inventive structure is preferred because they provide added advanta~es in provldin~ a~ainst peritonitis because the septum seal provides an additional bacterial barrier. As previously described, the cavity ahove the septum can be filled with antiseptic solution, such a~ Betadine~ brand iodine polyvinyl pyrolidone complex so as to provide a much more effective bacterial barrier than can be accomplished by a simple cap or a swabbin~ of the interior connector surfaces with an anti~eptic solution between uses.
Fi3ure 14 shows a Y-shaped, two channel percutaneous device in accordance with the present invention, useful in intermittent automatic peritoneal dialysis. The speciic embodiment of Fi~ure 14 is the co-invention of Louis C. Cosentino and Felix J. Martinez. As with the T-shaped device 10 and L-shaped device 60 described above, device 104 includes a septum closure within the stem cavity. Device 104, however, includes two downwardly extendin~ outlet arms 106, each of which is connected to a catheter mem~er 107. A cooperatin~ needle assembly 108 carries a pair of needles 110 which extend throu~h the septum and down into the interior of tubular arms 106. The two catheters 107 are placed in different portions of the peritoneal cavity. Dialysate may be pumped into the peritoneal cavity via one of needles 110 and catheters 107 and simultaneously used dialysate may be removed via the other catheter/needle combination.
Preferably, the inflow catheter wlll be placed above the outflow catheter so that the used dialysate may be drained without suction by ~ravity.
Arms 106 of device 104 extend downwardly so that needles 110 may be extended therein to prevent mixin~ of fresh and used dialysate. Alternatively, a T-shaped device similar to device 10 may be used if an intermediate central barrier and tube portion 12 is included so as to divicle - ].4 - ~ B

tube portion 12 lnto two separate chambers, one for Eillin~
and the other Eor drainin~ the d.ialysate.
A150, as with the blood access device, the de-vices of the present application useful :Eox peritoneal 5 dialysis applications will preferably be made of titani.um and, still more preferably, will contain an at least several an~strom layer of pyrolytic or vapor deposited carbon.

Claims (9)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A percutaneous implant especially suitable for peritoneal dialysis comprising:
a rigid, flangeless tubular body of biologically compatible material, said body having an open transcuta-neous stem portion with a smooth exterior surface and a lower portion, entirely below the surface when implanted, said lower portion including a porous tissue ingrowth media thereof on the exterior surface for anchoring the device to the body, and;
a flexible tubular catheter member in engagement with said lower body portion for providing fluid com-munication between said rigid tubular body and the perito-neal cavity.

2. A device as in Claim 1 wherein the biologically compatible material is titanium.

3. A device as in Claim 2 wherein the titanium sur-faces are coated with vapor deposited carbon.

4. A device as in Claim 1 wherein the tissue ingrowth media is a porous collar of polyethylenetereph-thalate.

5. A device as in Claim 1 wherein said tissue ingrowth media extends over the joint between said lower body portion and said catheter member.

6. A device as in Claim 1 wherein said catheter member includes a portion thereof having a plurality of perforations through the sides thereof.

7. A device as in Claim 1 wherein the tubular body includes, within the interior of the stem, an elastomeric septum member and means for holding said septum member in a sealed relationship therein, said septum defining an excu-taneous stem cavity within the device and providing an interruptable seal between said stem cavity and said catheter member.

8. A device as in Claim 7 wherein the rigid body lower portion comprises a plurality of tubular arms joined to and in fluid communication with said stem cavity, each said arm in engagement with a separate said flexible catheter member and wherein said septum provides a separate interruptable seal between each of said arms and said stem cavity.

9. A device as in Claim 8 including two said arms each extending downwardly from said stem portion in a generally V-shaped configuration.