US 3241554 A
Description (OCR text may contain errors)
March 22, 1966 G. COANDA 3,241,554
PERITONEAL DIALYSIS ENTRY DEVICE Filed Aug. 14, 1963 H618. H629. F/GJO. FIG. ll. Wvg/wop 4 9 8 mmf 60A/m4 United States Patent O 3,241,554 PERITONEAL DlALYSlS ENTRY DEVICE George Coanda, North Hollywood, Calif., assignor to Don Baxter, Inc., Glendale, Calif., a. corporation of Nevada Filed Aug. 14, 1963, Ser. No. 302,l1tl 13 Claims. (Cl. 12S-350) The present invention relates to a device to provide passage through the abdominal wall of a patient to allow pertioneal dialysis to be performed, and more particularly to a device that can be inserted in a patient and left there from one dialysis to the next.
Peritoneal dialysis is an excellent and accepted way to treat patients with chronic uremia or acute kidney shutdown. It involves filling the peritoneal cavity with dialyzing solution and using the peritoneum as a living, semipermeable membrane across which the blood is dialyzed. After the solution is left in the peritoneal cavity from 30 to 120 minutes it is drained out and additional solution is introduced into the cavity. When each batch of solution is removed from a patient it carries with it the undesired metabolites that have built up in the blood, such as urea, creatinine, and perhaps potassium. Blood, proteins, and the larger molecules will not cross the peritoneum and hence are not removed in the dialyzing solution. By regulating the concentration and composition of the dialyzing solution, the blood can be dialyzed back to normal. The average time for a complete peritoneal dialysis is between 8 and 36 hours.
Peritoneal dialysis can be acomplished in a small hospital or in a doctors office and does not have to be done by a trained and highly skilled team, as does dialysis with an artificial kidney. Once the dialysis is started, a nurse can watch the patient and keep track of the volumetric balance between the fluid put into the patient and the iiuid taken out. It is even possible for the patient or his family to perform the dialysis at home with the present peritoneal entry device.
One of the main problems in peritoneal dialysis has been the lack of a simple `means to put the solution into the peritoneal cavity and then remove it. One way of performing peritoneal dialysis was to directly insert a catheter into an incision made in the abdominal wall along the linea alba. After the dialysis was finished, the catheter was removed and the incision completely closed by suturing. When dialysis was again required, a new opening was made in the abdominal wall and the catheter inserted again. After the second dialysis, the catheter was removed and the second incision sutured shut. As can be seen, the patient would soon be full of incisions from the catheter, particularly if he required dialysis twice a week, as frequently is the case. Moreover, these periodic insertions of a catheter required the time of a physician, and caused pain for the patient. The catheter could be left in place permanently, but this would greatly increase the possibility of clogging in the catheter and also the possibility of peritonitis.
To overcome the disadvantages of leaving the catheter in place or of repeated punctures, the so-called peritoneal dialysis button was developed. This was essentially a semipermanently installed tube in the abdominal wall through which the catheter could be inserted. In regard to these buttons, semipermanent installation means that the tube was installed in the patient and left there from one dialysis to the next, but was removed when there was no longer any need for peritoneal dialysis. These entry tubes or buttons usually had a solid cap of some sort to seal them between dialyses. Most of these entry devices had an inner plate across the bottom end of the entry tube which went inside the patient and rested against ICC the peritoneum and inside the abdominal wall. This plate was needed to keep the entry device from being pulled out of the patient. On the exterior portion of the entry tube was a second plate that was either screwed onto external threads of the tube or by other means attached to the tube. This exterior plate prevented the entry tube from being pushed inside the patient.
These double plate entry devices were generally useable for peritoneal dialysis only after they had been inserted and the incision had been allowed to heal for several days. Another important difficulty is in inserting these devices in the abdominal wall. One way is to insert the device through a large incision along the linea alba wide enough to allow the inside plate to pass through and then to suture it in place. The other way is to make a small circular opening along the linea alba with a trocar and make a second large incision to one side of the linea alba. Through this second incision the whole hand of the surgeon carrying the entry tube with just the interior plate attached was inserted. The entry tube was then worked over to the hole created by the trocar and pushed up through the hole with the plate on the inside of the abdominal wall and peritoneum. This second method had the disadvantage of requiring two incisions, one for the hand and one for the entry device. Needless to say, both of these operations of inserting the entry device required a general anesthetic, a surgeon, and an operating room. Therefore, an entry device was not inserted unles required by the serious condition of the patient. Some of the entry devices were even designed with holes in the two plates for suturing them to the abdominal wall or for suturing them together through the abdominal wall. Because of the large incisions required for inserting these entry devices, dialysis could not be started for several days until the flesh healed around the incision. If dialysis were started too soon it would be painful to the patient, excessive bleeding might occur, or the stitches might tear loose.
The present invention overcomes the disadvantages inherent in the previous entry devices for peritoneal di alysis by providing two tubes, one slideably mounted within the other, and expandable wings on the outer tube near one end operated by the relative sliding movement of the two tubes. A locking nut arrangement is also provided on the outside tube and, with the expandable wings, locks the entry device in the abdominal wall so as to prevent any axial movement relative thereto.
One object of this invention is to provide a simple peritoneal entry device that can be inserted through a single small opening with only the use of a local anesthetic.
Another object of this invention is to provide a peritoneal entry device which does not require a laparotomy to insert and which can be removed without anesthesia.
Another object of this invention is to provide an improved peritoneal entry device of the type that can remain inthe abdominal wall between dialyses.
Still another object of this invention is to provide an improved peritoneal entry device that can easily be adjusted to t all persons regardless of the thickness of the abdominal Wall.
A still further object of this invention is to provide a peritoneal entry device that protrudes only slightly from the exterior abdominal wall and can be conveniently worn beneath ordinary clothing.
Another object of this invention is to provide a peritoneal entry device including a clamping means to securely hold the device in position.
Other objects of this invention Will become apparent upon further description of the device as shown in the drawings, in which:
FIGURE 1 is a perspective view of the entry device without the locking members and with the wing members in closed position;
FIGURE 2 is an exploded perspective view of the entry device with the wings in their expanded position;
FIGURE 3 is a sectional view of the front end of the entry device showing one method of attaching the two tubes;
FIGURE 4 is a sectional view of the front end of the entry `device showing another method of attaching the two tubes;
FIGURE 5 is an end view of FIGURE 2;
FIGURE 6 is an end view of FIGURE 1;
FIGURE 7 is a partial cross-sectional view of the assembled peritoneal entry device with an inserted catheter and installed in the abdominal wall;
FIGURE 8 is a cross-sectional view of the outer locking member;
FIGURE 9 is a cross-sectional view of the inner locking member;
FIGURE 10 is a top View of the outer locking member; and
FIGURE 11 is a top view of the inner locking member.
The peritoneal entry device includes an inner tube 1 slideably mounted within an outer tube 2 and attached to this outer tube at end 7. As shown in FIGURE l, longitudinal slots 5 are cut in the outer tube 2, leaving a series of strips 4 in outer tube 2. These strips are provided with a transverse fold line 6 near their center to aid with the folding out of the wings if needed. If desired, fold line 6 can be scored to facilitate bending. When the inner tube 1 is pulled while tube 2 is held stationary, as shown in FIGURE 2, the strips 4 bend at line 6 and form wings projecting outwardly from the tubes. It has been found helpful in first bending the wings along the center fold line 6 to heat the entry device to approximately 130 C. to soften the wings. This temperature will not harm the joint between the two tubes and once the wings have been bent, they can easily be expanded and contracted at room temperature. A depth gauge 3 is shown in FIGURES 1 and 2 along the outer tube 2 to indicate how far the tubular members have been inserted into the abdominal wall. Also, a mark 28 on the inner tube 1 shows when the wings 4 have been properly expanded. This mark will be covered by the outer tube 2 if the wings have not been properly expanded.
Once the tubular members have been inserted through the abdominal wall and the wings 4 expanded, the locking members are fitted over the outside of the outer tube 2 and clamped down. Internal locking member, generally designated as 8, has a at disk 9 which in turn has a wrench receiving section It). Integrally molded with disk 9 is a cylindrical member 12 having external threads and notches 13 cut in its sides. Cylindrical member 12 has a smooth bore which extends through disk 9 and thereby defines a passage 1I that is suitable to receive the outer tube 2. Disk 9 of internal locking member 8 fits against the skin Of the external abdominal wall and prevents the entry device from sliding further into the peritoneal cavity. To lock member 8 to outer tube 2 an external locking member generally indicated as 14 is employed. This external locking member includes a disk I5 and an integrally molded cylinder I8 which is both internally and externally threaded, and screws onto the internal locking member 8. A wrench receiving surface lid is also provided on external locking member 1.4. External locking member 14 has at one end of its threaded bore 17 an inwardly beveled clamping surface 2S adapted to engage the end of threaded cylinder I2 and clamp said cylinder rmly around tube 2 by partially closing the notches 13. This beveled clamping surface is more clearly shown in FIGURE 8. Fitting over the external threads of member 14 is cap 19.
FIGURE 5 is an end view of the entry device with the wings in their expanded attitude. Although three wings 4 have been shown as a particular embodiment, it is entirely within the scope of this invention to have any number of i wings to hold the entry device from pulling out of the abdominal wall of the patient.
FIGURE 6 shows the end view of the tubular members with the wings in their retracted position.
FIGURES 3 and 4 illustrate two ways of attaching the two tubes together at their forward end. FIGURE 3 shows a type of rivet joint that is particularly suited to join the two tubes when the outer tube is made of polypropylene and the inner tube of nylon. In connecting the two tubes together by the rivet method, the inner tube 1 is cut with a straight cut across one end. Near this end is bored a series of small holes 20. The outer tube 2 with its cutaway slots 5 and wing portions 4 is slid over the inner tube until the two ends of the tubes are nearly adjacent to one another. Heat is applied to both tubes, and the outer tube softens before the inner tube if the outer tube is polypropylene and the inner tube is nylon. lf the front end of the tube assembly is placed over a form with a core member adapted to tit inside the inner tube, the softening of the outer tube 2 will cause a sort of rivet joint to be formed. The polypropylene tube will form an integral rivet 2l projecting into each of the holes 2li or the nylon tube. This forms a firm joint because of the concentric, close-fitting relationship of the two joined tubes. The stubs cannot be pulled out without stretching the outer tube 2 or collapsing the inner tube l. Because of the rigidity of the tubes, this is impossible under normal circumstances.
Another method of joining the two tubes together at one end is shown in FIGURE 4. This type of joint is particularly useful when both tubes are made of the same material. In this figure, an outer tube 2 is placed over an inner tube I and moved with respect to the inner tube until the ends of both tubes are nearly adjacent. A metallic form is then placed over the ends of the two tubes. The form has a core to fit the inside bore of the inside tube 1, and a tapered portion to receive the outer surface of outer tube 2. Upon heating the form, the polypropylene is softened and caused to conform to the configuration shown in FIGURE 4. Because the two tubes soften and tend to iiow together at one end, they join somewhere in the vicinity of dotted line 23, indicated in this gure. However, no joint is actually visible and the two tubes fuse together and form a continuous homogeneous end portion on the two tubes. Tubes of polypropylene work well in this joining method.
Forms can be used with either of the two joining methods of FIGURES 3 and 4 to cause the end of the turbe assembly to conform to any desired shape. While the tapered end shown will allow easy entry into a trocar, the ends could also be iiat with no taper if the trocar was of sufficient size to allow the tube assembly to be easily inserted.
Only two combinations of tube material have been given as illustrations, one when both tubes are of polypropylene and one when the outer tube is of polypropylene and the inner tube is of nylon. It is also possible to make the tube assembly with an outer tube of Tefion and the inner tube of nylon. Other materials having the same general characteristics of polypropylene, nylon, and Teiion could also be used.
Turning now to FIGURE 7, it can be readily seen how the peritoneal entry device is positioned in actual use. 27 represents a cross-section of the abdominal wall and 27a represents the skin on the outer surface of the abdominal wall. Directly inside the abdominal wall is the peritoneum 29, which is a membrane that is not firmly attached to the inside of the abdominal wall. Instead, it usually lies against the inside abdominal wall surface but is free to move away from it. The present peritoneal entry device provides a tubular passage through both the abdominal wall and the peritoneum, and makes it impossible to run any solution between the abdominal wall and the peritoneum.
FIGURE 7 shows the peritoneal entry device in its completely inserted position. Expanded wings 4, which have folded at fold lines 6, form an interior backing surface that prevents any lateral movement of the device out of the patient (that is, to the right in FIGURE 7). It is preferable to expand the wings completely to the point of having both halves of each Wing touching each other. This will give less chance for omentum to grow between and around the wings, than if the halves of each wing were spaced apart in triangular fashion. On the exterior surface of the labdominal wall, disk 9 of internal locking member 8 rests firmly against the skin of the abdomen. As can be seen in FIGURE 7, the abdominal wall 27 and the peritoneum 29 are held between the expanded wings 4 on the interior, and the disk 9 of locking member 8 on the exterior. Thus, because the device is firmly affixed to the abdominal wall, any movement of the abdominal wall and peritoneum, such as in breathing, will move tbe peritoneal entry device with it. The entry device of the present invention can be fitted to the particular patient regardless of his leanness or fatness because the locking nut mechanism can be positioned anywhere along outer tube 2 and locked in place.
Fitting over the end of locking member 14 is a cap 19. This cap has a hole in its top near the center to allow a catheter 26 to be inserted. Inside of cap 19 is a rubber sealing washer24 with a hole slightly smaller than the outside diameter of catheter 26. This hole will stretch to receive the catheter 26 when it is inserted through the hole in cap 19 and washer 2d. Upon tightening cap 19 on locking member 14, a tight seal is formed between -the locking member 14 and catheter 26. It is also possible to insert a second washer 22 between the rubber washer 24 and the cap 19 to allow rubber washer 24 to slide relative to the cap while the rubber Washer is tightly sealed around a catheter. If the rubber washer can slide Irelative to cap 19, then the cap can be tightened or loosened without rotating catheter 26. Also, by slightly unscrewing the cap, the catheter can be manipulated within the peritoneal cavity to a position where solution can easily flow in and out of the holes in the catheter. This second washer could be made of Teflon, Tefloncoated fabric, or other similar material.
The catheter 26 with a series of holes 27 at its forward end could be any type catheter, but one catheter that has proven very useful in conjunction with the peritoneal dialysis entry device is the catheter described in United States Patent No. 3,064,653, issued under the inventors name, George Coanda, on November 20, 1962.
FIGURES 8 and l0 show the cross section and top views, respectively, of outer locking member 14. In FIG- URE 8, it can be seen that disk 15 and cylinder 1S are molded in one piece with the cylinder threaded both internally at 17 and externally at 18a. The top opening 30 in cylinder 18 is smaller than the remaining portion of the bore because of the tapered locking surface 25.
The cross-sectional view of FIGURE 9 of inner locking member 8 shows the wedge-shaped notches 1?. There are a series of these notches yaround the locking member 8 and their number can vary anywhere from one to ten. FIGURE 11 shows four of these notches 13 in the top View of inner locking member 8. The internal bore 11 of inner locking member 8 is smooth to clamp around the outer tube member 2 while the exterior of the cylindrical portion 12 is threaded to receive the inner threads 17 of outer locking member 14.
The procedure for inserting the peritoneal entry device is quite simple. First, the area is prepared and a local Ianesthetic, usually procaine, is applied. Next, the peritoneal cavity is injected with from one to two liters of solution, depending on the patient. The solution is injected through a long needle connected by tubing to a regular solution container. The purpose for first injecting at least one liter of solution is to provide a positive fluid backing for the pertoneum, forcing it against the interor abdominal wall. If there were no uid rst injected, it would 6 be very easy to insert the peritoneal entry device and not pierce the peritoneum. This would allow the dialyzing fluid to flow into the abdominal cavity between the abdominal wall and the peritoneum. 1
After the solution has been injected into the peritonea cavity with the hypodermic needle, a small incision is made along the linea alba yabout one third of the way between the umbilicus and the pubic bone. The incision is only through the skin and a slight distance into the muscle layer, but is not completely through the abdominal wall. Next, a trocar is inserted in the incision and pushed through the abdominal wall to the peritoneum. The trocar acts to sort of spread the tissue without cutting it, thereby leaving a tight flesh seal -around the trocar. After passing through the abdominal wall, the trocar is pushed against the peritoneum and a slight pop is felt as the trocar punctures the peritoneum. Having inserted the trocar, the perforator is removed, leaving the cannula in place.
With the cannula of the trocar in place, the tube assembly of the peritoneal entry device is inserted through the cannula. After this insertion, the cannula is removed, leaving the tube assembly extending through the abdominal wall and the peritoneum. The wings of the tube assembly are then extended by pulling on the inner tube 1, which extends past the outer tube 2, and at the same time pushing on the outer tube. The friction between the sliding tubes must be great enough to prevent the tubes from accidently sliding relative to each other, and collapsing the wings once they are extended. Sometimes,I because of this friction, the tubes are fairly hard to slide when extending the Wings, especially if the hands are wet.. A better grip is sometimes required on the two sliding tubes. This is accomplished by simply sliding a common washer (not shown) over the inner tube 1 and forcing it against the end of the outer tube 2. The washer has a hole large enough to go over the inner tube but not large enough to go over the outer tube. If additional gripping surface is needed for the inner tube 1, a simple screw hook (not shown) or other similar `device can be screwed into the end of inner tube 1. By pulling on the screw hook and pushing on the washer, the wings of the peritoneal entry device can be easily expanded even with wet hands. Once the tube assembly is in place in the abdominal wall with the wings expanded, the locking members are installed. With dry hands, the washer and screw hook would not usually be needed to expand the wings.
When the entry device has been locked in place, inside tube 1 and outside tube 2 protrude out through the opening in the locking assembly. These protruding tubes are cut off even with the top surface of locking member 14 with a sterile razor blade. It has been found in practice that a rocking motion of the razor blade makes cutting through the two tubes much easier than either a straight pushing of the razor blade against the tubes or a slicing action.
Having cut oif the excess length of the tube assembly and left a at surface across the top of the outer locking member 14, a catheter 26 can be inserted through the bore of the peritoneal entry device. Cap 19 with its rubber sealing washer 24 can either be placed over the catheter, and the catheter and cap installed simultaneously, or the cap can be screwed on first and the catheter inserted through the hole in the cap.
The catheter 26 is then worked around until it is in a free unobstructed position within the peritoneal cavity. Bottles of solution are connected to the catheter by means of tubing. Solution is run into the cavity, and the tubing connecting the catheter and solution bottles is clamped shut before the last solution bottle runs dry. After the solution has remained in the patient the required length of time, usually 15 to 120 minutes, it is withdrawn by siphoning. When the cavity is drained, fresh solution is introduced into the cavity, left there a set period of time, and then drained out. The cycle of lling the peritoneal cavity, leaving the solution in the cavity suiciently long for dialysis to take place across the semipermeable niembrane around the blood vessels of the intestines and other organs within the peritoneal cavity, and removing the solution is continued until toxic materials in the blood are reduced to the desired level.
After a particular dialysis is completed, it is a simple matter to remove cap 19, which has a hole in its top, along with catheter 26, and close off the peritoneal entry device with a cap similar to cap 19 but with no hole in its top. Thus, between dialyses the entry device can be closed, and if the patient is otherwise able, he can go about his daily business with the semipermanent peritoneal entry device or button installed.
At the next required dialysis, the solid top cap is removed and a sterilized catheter and cap I9 are connected to the entry device. These periodic dialyses are continued until it is felt that dialysis is no longer required. Often in the case of acute kidney failure, the kidney begins to function again and the entry device can be removed.
Removal of the button begins with removing cap I9 and the two locking members 8 and I4. The wings 4 are retracted by pushing the inner tube 1 down inside outer tube 2. Since the two tubes were cut oit" evenly when the entry device was inserted, holding means have to be used to keep the outer tube from axially sliding. An extractor for holding the outertube, and at the same time pushing the inner tube down inside to retract the wings, is the subject of a separate application, Serial Number 304,497, filed on August 26, 1963. With the wings retracted, the tube assembly can be simply pulled out of the abdominal wall. The small hole left after Withdrawal of the tube assembly can then be sutured with just a local anesthetic.
Perhaps the four most important features of the present invention are: (1) the device does not require a laparotomy to insert; (2) it can remain in the patient with little or no discomfort between dialyses; (3) it can be used immediately after insertion; and (4) it can be readily removed without an anesthetic.
In the past, doctors have been somewhat reluctant to use repeated peritoneal dialysis in cases of acute renal failure because of the involved laparotomy required to insert a button and the several days required for healing before it could be used. Buttons were used in acute cases only when absolutely necessary and not as a preventive measure. So far, peritoneal dialysis buttons have been to a large extent limited to chronic renal shutdown where there was no hope of kidney function returning. The present peritoneal dialysis button can also be used in chronic renal shutdown. However, it is particularly useful for acute renal failure where perhaps two or more dialyses are suiiicient to relieve the kidneys and allow them to return to their natural functioning.
While I have shown and described certain specific ernbodiments of my invention for the purpose of illustration, it should be understood that many changes and modifications may be made without departing from the spirit and scope of my invention.
I. In a peritoneal entry device comprising two telescoped tubes having inner and outer ends iixedly secured at said inner end and having relative axial movement, the outer tube including expandable and retractible retaining wings adjacent said inner end operable by relative movement of said inner tube with respect to said outer tube, said inner tube including an axial through bore, a catheter tube removable disposed in said inner tube and including an administrating end yportion projecting beyond said inner end of said outer tube, clamping-and-locking means circumposed about the outer ends of said tubes and permitting said catheter tube to have relative movement with respect to said clamped tubes, and sealing cap means circumposed about said catheter tube and manually-removably engaged on said clamping-and-locking means, said sealing cap means including internal washer means sealingly engaged about said catheter tube, said sealing cap means being manually adjustable for permitting axial and rotatable movement of said catheter as well as removal and replacement of said catheter tube.
2. A semipermanent peritoneal entry device comprismg:
(a) an inner tube open at both ends and having an open center bore adapted to receive a catheter,
(b) an outer tube slideably mounted on the outside of said inner tube and attached to said inner tube near one open end,
(c) a series of longitudinal strips in said outer tube, said strips formed by longitudinal slots in said outer tube between said strips, said strips buckling to form a series of iiared wings upon axial movement of the two tubes relative to each other,
(d) an inner locking member fitting over said outer tube,
(e) an outer locking member tting over said inner locking member to squeeze said inner locking member tightly around the outside of said outer tube, said locking members adapted to prevent axial movement of said entry device relative to a patients abdominal wall, and
(f) a cap fitting over said outer locking member.
3. A semipermanent peritoneal entry device as set forth in claim 2 wherein said inner locking member comprises:
(a) an exteriorly threaded cylinder, said cylinder having a series of longitudinal notches to allow a clamping action of said inner locking member about said outer tube, and
(b) a flat plate attached to said cylinder at one end, said plate being perpendicular to the axis of said cylinder.
4. A semipermanent peritoneal entry device as set forth in claim 3 wherein said tiat plate has at least two at wrenching surfaces on its periphery.
5. A semipermanent peritoneal entry device as set forth in claim 2 wherein said outer locking member comprises:
(a) an externally and internally threaded cylinder,
(b) an annular, inwardly sloping clamping surface at one end of the bore of said cylinder, and
(c) a iat disk attached to said cylinder at the opposite end at an attitude perpendicular to the axis of said cylinder.
6. A semipermanent peritoneal entry device as set forth in claim 5 wherein said fiat plate has at least two dat wrenching surfaces on its periphery.
'7. A semipermanent peritoneal entry device as set forth in claim 2 wherein said cap has an axial hole in its top and sealing means interior of said cap to seal against leakage around a catheter inserted through said hole.
8. A semipermanent peritoneal entry device as set forth in claim 2 wherein said inner and outer tubes at their attached ends include:
(a) an end section having a uniform bore throughout and a combined Wall thickness yprogressively thinner toward the tip of said end section, and
(b) an outer surface of said end section tapering radially inward toward the tip of said end section.
9. A semipermanent peritoneal entry device as set forth in claim 2 wherein the tip of said end section is formed by an inwardly curved section of said outer tube.
iti. A semipermanent peritoneal entry device as set forth in claim 2 wherein said inner tube has a series of radial holes near its attached end, said holes being filled with rivet stud members extending inwardly from said outer tube.
l1. A semipermanent peritoneal entry device as set forth in claim 2 wherein said cap has a sealing washer fitted inside and a sliding washer fitted between said seal- 9 10 ing washer and said cap, said washers and cap each said cylinder which is adapted to squeeze said inner having an axially aligned hole to receive a catheter. locking member tightly around the outside of said 12. A semipermanent peritoneahentry device as set outer tube to `prevent axial movement of 'the entry forth in claim 11 wherein sa1d sealing washer 1s rubber device when installed through an abdommal wall, and said sliding Washeris Teon. 5 and a at disk attached to said cylinder at an oppo- 13. A sempermanent peritoneal entry device comsite end and positioned perpendicular to the axis prising: of said cylinder which flat disk is adapted to abut (a) an inner tube open at both ends and having an against a patients abdominal Wall; and
open center bore adapted to receive a catheter; (f) a cap tting over said outer locking member. (b) an outer tube slideably mounted on lthe outside of 1o R f C t d b th E saidinner tube; e erences 1 e y e xammer (c) lateratlly Itexnandable means Csonnlctld to the .inner UNITED STATES PATENTS an ou er u es near one en W 1c means 1s expandable by axial movement of the inner and outer T 88695 4/1869 Davldson 128`243 2,616,429 11/ 1952 Merenlender 128--350 tubesrelatweto each other 15 3039 468 6/1962 Price 12s-34s (dur inner lockmg member :fitting over sald outer 3,050,066 8/1962 Koehn n 128 349 3,108,595 10/ 1963 Overment 128-350 (e) an outer locking member ttin-g over said inner locking member and including yan externally and RICHARD A G AUDET Primary Examiner internally threaded cylinder, an annular, inwardly 20 sloping clamping surface at one end of a bore of