CA2152488A1

CA2152488A1 - Catheter for capd

Info

Publication number: CA2152488A1
Application number: CA002152488A
Authority: CA
Inventors: Makoto Ishizaki
Original assignee: Individual
Current assignee: HAYASHIDERA MEDINOORU CO Ltd
Priority date: 1992-12-24
Filing date: 1993-11-04
Publication date: 1994-07-07
Also published as: US5752939A; WO1994014483A1; JPH06190051A; JP3146332B2

Abstract

This invention relates to improvements in a catheter for injection/drainage of a dialysis solution of CAPD which is hemocatharsis for chronic renal failure patient, and its object is to allow complication such as peritonitis, etc. to be as minimum as possible, and to improve the tip migration of the catheter within the peritoneal cavity, thus to eliminate dialysis solution drainage failure.
The catheter for CAPD is constituted as follows: A
hypodermic tunnel portion is provided at the intermediate portion of a tube formed with a soft material having human body compatibility, one leg portion thereof is caused to serve as an external extension, the other leg portion is caused to serve as a peritoneal cavity insertion portion having suction/drain holes, a first cuff is provided at the boundary between the hypodermic tunnel portion and the peritoneal cavity insertion portion, the portion in the vicinity of the first cuff toward the inside of the peritoneal cavity from the first cuff is caused to be of a structure such that the restoring force of the tube is enhanced, the hypodermic tunnel portion is bent in a loop form so as to take an inverse U-shape, the second cuff is disposed at the vertex of the loop, the second cuff is sutured and fixed to the fascia, and the first cuff is disposed at a position corresponding to the peritoneum.

Description

DESCRIPTION

Catheter for CAPD

Technical Field This invention relates to an improvement in catheter for injection/drainage of dialysis solution of CAPD (Continuous Ambulatory Peritoneal Dialysis) which is a hemocatharsis for chronic renal failure patients.
Background Art CAPD which is a hemocatharsis for chronic renal failure patients has been recognized as a treatment method in which the Health Insurance is applied from March, 1985 in Japan. From April 1, 1986, only by notification at the local self-govering body in the district where medical institutions are established, CAPD has been able to be put into practice with ease. For this reason, CAPD has been popuralized and put into practice at many hospitals and clinics.
The concept of the CAPD was announced by Popovich and Moncrief in U.S.A. in 1976. In this CAPD, a patient carries a bag of a soft material such as polyvinyl chloride in which dialysis solution is contained to feed the dialysis solution from the soft bag into the peritoneal cavity by using a tube to thereby carry out dialysis while working about without sense of imcompatiblity.
A closed system of the CAPD which is the fundamental principle is comprised, as shown in Fig. 1, of a catheter A, a catheter adapter B of titanium, a connecting tube C, and a bag D of polyvinyl chloride in which peritoneal dialysis solution is contained.
A catheter for CAPD which was used in the beginning is called a Tenckhoff type catheter. As shown in Fig. 2, this catheter is such that a hypodermic tunnel portion F is provided at the intermediate portion of an elongated straight tube E of silicon rubber, one leg portion thereof is caused to serve as an external extension G, the other leg portion thereof is caused to serves as a peritoneal cavity insertion portion H having suction/drainage holes, a first cuff I is provided at the boundary between the hypodermic tunnel portion F and the peritoneal cavity insertion portion H, and a second cuff J is provided with a suitable spacing therefrom at the hypodermic tunnel portion F. However, in order to prevent tunnel infection, the exit site is required to be directed downward. Ordinarily, an operation is carried out so as to implant a straight tube while allowing it to be bent in an inverse U-shape. This operation is difficult. In addition, there is a marked tendency for the second cuff to attempt to be protruded to the outside of the skin by resilience force of the bending portion. In view of this, as shown in Fig. 3, there is proposed a Swan Neck type catheter in which the hypodermic tunnel portion F between the first cuff and the second cuff is formed in advance inverse U-shaped. At present, such Swan Neck type catheters are widely used. In the figure, reference symbol K denotes in~ection/drainage holes provided at the front end portion of the peritoneal cavity insertion portion H.
The important complication of the CAPD is peritonitis. It - 3 215248~
is considered that the greater part of the peritonitis is based on troubles resulting from the catheter. It has been clear that improvements in the biological compatibility of the catheter, its shape and/or implantation technique thereof, etc. allow these complications to be dramatically decreased. Studies therefor have been developed. The technical problems thereof are as follows.
Conventional Swan Neck type catheters are bent in an ordinary condition between cuffs. However, since this portion is constituted as a tube of a soft material such as silicon rubber, etc., excessive bending is apt to occur. As a result, the peritoneal cavity may be confined or narrowed. To prevent such phenomenon at the time of operation, ablation of a broad connective tissue is required. Further, although forming a hypodermic tunnel by trocar in a form of loop immediately on the abdominal wall fascia is seemingly easy, this is very difficult in an actual manipulation. Namely, in order to place the second cuff in an upper hypodermic tissue at the depth of 2 cm from the exit site, it is inevitably required to allow the tissue to be ablated to much degree. Thus, an excessive dead cavity will be formed. As a result, there occurs the drawback that organization by the connective tissue of the second cuff is delayed. In addition, since the second cuff is near the exit site, infection is apt to result. Since the second cuff is not sutured and fixed at the time of operation, it takes much time in completion of healing of the exit site.
A first object of this invention is to improve such conventional catheters to prevent exit site infection or - 4 215~488 hypodermic tunnel infection, to dramatically decrease frequency of the peritonitis fatal to the CAPD, etc. to thereby allow complication to be as minimum as possible.
Further, whether drainage of the dialysis solution in the CAPD is good or bad is an important factor which affects the dialysis efficiency. However, in the case of the conventional catheter, since the resilience force on the peritoneal cavity side from the first cuff is weak, such catheter is apt to abnormally migrate by the intestinal peristaltic vermicular motion at the portion within the peritoneal cavity. In addition, since its restoring force is weak, there are many instances where a suitable restore to the Douglas cavity cannot be carried out.
In view of this, a second object of this invention is to employ such a configuration to increase the restoring force at the beginning portion within the peritoneal cavity of the catheter to thereby improve a positional extraordinary condition (tip migration) of the front end portion of the catheter within the peritoneal cavity, thus to eliminate the dialysis solution drainage failure.

Disclosure of the Invention To achieve the above-mentioned objects, this invention is constituted with the following means.
A first invention for which patent is sought to be obtained is directed to a catheter for CAPD in which a hypodermic tunnel portion is provided at the intermediate portion of a tube formed of soft material having the compatibility with the human body, one leg portion thereof is caused to serve as an external 215~488 extension, the other leg portion thereof is caused to serve as a peritoneal cavity insertion portion having suction/drain holes, a first cuff is provided at the boundary between the hypodermic tunnel portion and the peritoneal cavity insertion portion, and a second cuff is provided with a suitable spacing at the hypodermic tunnel portion, wherein the hypodermic tunnel portion is bent in a form of loop so that it takes an inverse U-shape, the second cuff is disposed at the vertex (summit) of the loop, and the first cuff is disposed at a position corresponding to the peritoneum.
Further, a second invention for which patent is sought to be obtained is directed to a catheter in which, in the catheter for CAPD of the first invention, the portion in the vicinity of the first cuff toward the inside of the peritoneal cavity from the first cuff of the peritoneal cavity insertion portion in the catheter for CAPD is of a structure such that the restoring force of the tube is enhanced.
A third invention for which patent is sought to be obtained is directed to a catheter for CAPD wherein there is employed a structure such that the tube thickness is caused to be great over a predetermined length of the tube toward the inside of the peritoneal cavity from the first cuff of the peritoneal cavity insertion portion, thus to enhance the restoring force.
A fourth invention for which patent is sought to be obtained is directed to a catheter for CAPD wherein the second cuff of the hypodermic tunnel portion is provided at the vertex (summit) of the loop bent in an inverse U-shape to reinforce it.
A fifth invention for which patent is sought to be obtained 2152~88 is directed to a catheter for CAPD wherein the hypodermic tunnel portion is bent in a loop form so as to take an inverse U-shape, the second cuff is disposed at the vertex (summit) of the loop, the first cuff is disposed at a position corresponding to the peritoneum, the first cuff is caused to be of a structure such that it can be fixed on the peritoneum, and the second cuff is caused to be of a structure such that it can be fixed on the abdominal rectus fascia.
It is only required for the tube in this invention that it is formed of soft material having compatibility with the human body. In actual terms, a tube of silicon rubber is suitable for this purpose. However, it is of course that the tube which can be used in the invention is not limited to such tube of silicon rubber. The thickness of the tube is not particularly limited as long as the human body compatibility is taken into consideration. Generally, a tube having an outside diameter of 4.9 i 0.5 mm and an inside diameter of 2.6 i 0.5 mm is suitable.
In addition, the cuff is formed by winding and fixing an unwoven cloth of dacron having the human body compatibility onto the zo outer circumference of the tube. Any material having human body compatibility may be used as the material of the cuff. The material of the cuff is not limited to dacron.

Brief Description of the Drawings Fig. 1 is a perspective view showing a closed system of CAPD
which is the fundamental principle; Fig. 2 is a front view showing a conventional Tenckhoff type catheter, Fig. 3 is a front view showing a Swan neck type catheter conventionally widely - 215~48~

used; Fig. 4 is a catheter for CAPD of the inverse U-shape type according to this invention, wherein Fig. 4-1 is a front view showing a catheter for CAPD of the inverse U-shape type according to this invention, and Fig. 4-2 is a cross sectional view taken along the line II-II in Fig. 4-1; Fig. 5 is an explanatory view showing, by using Figs. 5-1 to 5-9, in succession steps of a method of implanting a catheter for CAPD of this invention, wherein Fig. 5-1 is an explanatory view showing a skin incised (opened) portion, Fig. 5-2 is a perspective view showing the state where the stylet is inserted through catheter for CAPD
according to this invention to bend it so that an angle of the front end thereof at the time of insertion becomes equal to 150 degrees, Fig. 5-3 is a perspective view showing tobacco suture state of the peritoneum incised (opened) portion, Fig. 5-4 is an explanatory view showing the state where the first cuff is fixed on the peritoneum and the fascia, Fig. 5-5 is an explanatory view showing the state where the hypodermic tunnel is made by trocar, Fig. 5-6 is an explanatory view showing the state where the hypodermic tunnel of the second cuff portion is made by trocar in a manner similar to the above, Fig. 5-7 is an explanatory view showing the state where the second cuff is fixed on the fascia, Fig. 5-8 is a cross sectional view when implantation of the catheter is completed, and Fig. 5-9 is a front view showing the state where the catheter for CAPD according to this invention is implanted to suture two wounds.

Best Mode for Carrying Out the Invention This invention will now be described in detail in accordance 21~2488 with the embodiment shown.
Fig. 4 is a front view showing a catheter for CAPD according to this invention. In this figure, reference numeral 1 denotes a tube of a soft material such as silicon rubber. At the intermediate portion of the tube 1, a hypodermic tunnel portion 2 is provided. One leg portion of the hypodermic tunnel portion 2 is caused to serve as an external extension 3, and the other leg portion thereof is caused to serve as a peritoneal cavity insertion portion 5 having suction/drain holes 4. The silicon rubber tube 1 is a transparent tube having the entire length of 435 + 20 mm, the outside diameter of 4.9 i 0.5 mm, and the inside diameter of 2.6 i 0.5 mm. To a portion of the circumference thereof, a radiopaque stripe 9 in the longitudinal axis direction is implemented. The peritoneal cavity insertion portion 5 is 175 + 10 mm long. On the side surface of 85 ~ 10 mm of the front end portion thereof, suction/drain holes 4 of 0.5 ~ 0.7 mm are bored at predetermined intervals. On the outer circumference of the tube at the bottom portion of the peritoneal cavity insertion portion 5, a first cuff 7 (about 10 mm) of dacron is provided.
In addition, there is employed a structure 6 such that the thickness of the tube at the portion of about 40 i 5 mm toward the inside of the peritoneal cavity from the first cuff 7 of the peritoneal cavity insertion portion 5 is caused to be great by about 6.0 i 0.5 mm so that the restoring force is enhanced. In a direction toward the intermediate portion from the first cuff 7, hypodermic tunnel portion 2 is provided. In this hypodermic tunnel portion 2, a semi-circular loop 2a having a diameter of about 60 mm is formed. By this bending, this catheter is 2iS2488 g substantially inverse U-shaped as a whole. In addition, at the vertex (summit) of the loop 2a, a second cuff 8 (about 10 mm) of dacron is disposed. The length between the first cuff 7 and the second cuff 8 is about 60 mm. In a direction extending from the second cuff 8, an external extension 3 of 180 i 20 mm is formed in an extended manner.
A method of implanting the catheter of this invention will now be described with reference to the attached drawings.
(1) Incision of skin is conducted as follows. The catheter is placed on the abdominal wall. At this time, the height of the first cuff 7 is determined in such a manner that the position of a first side hole of the catheter is caused to be in correspondence with the pubic bone connective upper edge, and the first cuff 7 is then caused to be in correspondence with the center of the abdominal rectus. Then, the positions of the first cuff 7 and the second cuff 8 are marked to apply incision of skin of about 5 cm along the longitudinal axis of the first cuff 7 under the local anesthesia (Fig. 5-1).
(2) Hypodermic fatty is incised by the electric surgical knife and good hemostasis is essential. Further, the anterior sheath portion of the abdominal rectus fascia is exposed while pushing aside the fatty layer by using a hook. Then, the fascia is incised by 3 - 4 cm to allow the surgical knife to enter the posterior sheath portion of the fascia without cutting the abdominal rectus by the hook. Local infiltration anesthesia is sufficiently implemented to the peritoneal incised portion to apply small incision of 5 mm so as not to injure the intestines while rasing together the posterior sheath portion of the 215~88 abdominal rectus fascia and the peritoneum by using a hook pin.
Front end of a Weston-Roberts catheter for IPD is tentatively inserted from the abdominal small incised hole into the Douglas cavity to confirm its contact. With a view to allowing the catheter according to this invention to be apt to be inserted, physiological saline of about 100 mQ is injected from that catheter and the catheter is removed. Then, a stylet is inserted into the catheter according to this invention by using lubricant so that the bending angle is equal to about 150 degrees at the portion of about 5 cm from the catheter front end (Fig. 5-2).
The catheter front end is inserted from the small incised hole to thrust the front end directed forward until it comes into contact with the right pubic bone center along the peritoneal cavity front wall. The ring portion of the stylet is gripped and is drawn from that position along the abdominal wall while externally rotating it by about 180 degrees. As a result, resistance is suddenly lost at the entrance of the pelvis minor.
When the catheter front end is rotated and thrust by 270 degrees in total while externally rotating it, the front end portion can be precisely inserted into the Douglas cavity. Then, the catheter is rotated so that the radiopaque white line is positioned on the rear surface side while fixing the stylet.
Thereafter, only the stylet is removed while holding the catheter so as not to be slipped off. When the catheter front end is precisely inserted into the Douglas cavity, and physiological saline of 10 m~ is injected into an injector to conduct cleaning from the catheter, taking in and out of solution can be carried out without any resistance.

(3) The peritoneum and the posterior fascia sheath which have been incised are together subjected to four-point support by using pearn forceps to apply tobacco suture by using a # 3-0 Dexon thread. Until this manipulation, the first cuff 7 is caused to be placed within the peritoneal cavity (Fig. 5-3).
Then, the first cuff 7 is taken out to the outside of the peritoneal cavity L to implement tobacco suture (the mouth of the opening portions is closed and the first cuff is sutured thereto in the state where tobacco is seemingly in the mouth) to the peritoneum L to sufficiently clamp their portions to apply tuberculation thereto to further fix it to the first cuff 7 of dacron by using that thread. Similarly, the peripheral portion is subjected to four-point fixing by using Dexon thread at an interval of 90 degrees to allow that portion to be in a water tight seal state (Fig. 5-4). At this time point, it is confirmed by X-ray photographing that the catheter front end is precisely inserted into the Douglas cavity.

(4) A Penrose drain is split into three portions to insert them into the portion in the vicinity of the second cuff 8 to suture the abdominal rectus fascia anterior sheath. At this time, the catheter is caused to be taken out from the upper end of wound. Namely, the portion of the catheter within the peritoneal cavity is caused to be directed downward at all times.

(5) The skin of about 2 cm is incised at the second cuff 8 portion, and the fatty layer is also incised by using an electric surgical knife while arresting bleeding to expose the fascia.
Immediately above the fascia, the catheter is passed from the first cuff incised wound toward the second cuff incised wound by 21~2488 -using the trocar tunneler (Fig. 5-5). Similarly, the catheter is taken out from the skin at the portion of 4 ~ 5 cm from the second cuff 8 toward the downward direction from the wound of the second cuff 8 (Fig. 5-6). Then, the second cuff 8 is fixed on the fascia M by using a # 3-0 Dexon thread with two stitches (Fig. 5-7)-(6) When two wounds are sutured in a manner separated intodouble layers to close those wounds, the catheter is implanted as shown in Fig. 5-9. Fig. 5-8 is a cross sectional view after the catheter is implanted. A catheter adapter is fitted over the catheter front end portion outside the human body to connect a connecting tube thereto to start CAPD six times a day by using a 1.5 % dianeal solution of 1~.
The result of the study of the frequency of complication of the catheter for CAPD according to this invention and the conventional catheter was shown in Table 1. This invention reduced frequencies of the permanent catheter tip migration to 1/12, exit site infection to 1/4, tunnel infection to 1/2, and peritonitis to 1/4 of the conventional type catheter. Namely, peritonitis has a low frequency of once a month with respect to 91.4 patients. In addition, all the catheters of this invention are functioning properly. As compared to the prior art, CAPD
could be carried out in a more safety manner.
The No. of cases of CAPD using the catheter according to the third invention is 60. The total observation (cumulative) period is 1359 months, and the result of complications which have occurred during that observation period is as shown in Table 2.
From this result, it is seen that frequency of complication has been further reduced.

21~2~88 Table 1 Comparisopn between complications of the catheter of this invention and complications of the conventional catheter Catheter of this Conventional invention catheter No. of cases 37 32 Ratio between man 27:10 22:9 and woman (man :
woman) Observation period 457 465 (patient month) Permanent catheter 1 12 tip migration (patient month) (1/457) (1/38.8) 15 Exit site 3 13 infection (patient month) (1/152.3) (1/35.8) Tunnel infection 3 6 (patient-month) (1/152.3) (1/77.5) 20 Peritonitis 5 21 (patient-month) (1/91.4) (1/22.1) Cateter function 0 11 failure (patient month) (1/42.3) 2152~88 Table 2 Result of cumulative period (patient month) 1359 months with respect to 60 patients using this invention No. of cases Case rate (patient-year) Permanent catheter 6 0.05 tip migration Exit site 17 0.15 infection Tunnel ~nfection 12 0.11 Peritonitis 34 0.30 Catheter 3 0.03 replacement Industrial Applicability In accordance with this invention, in a catheter for CAPD, the hypodermic tunnel portion is bent in a loop form so as to take an inverse U-shape, and the second cuff is disposed at its loop vertex to reinforce its portion. Accordingly, it is possible to prevent isthmus of the catheter internal cavity resulting from an excessive bending at the time of operation of the hypodermic tunnel portion.
Further, the second cuff is caused to be positioned at vertex of the inverse U-shaped loop, thereby making it possible to minimize formation of dead cavity after ablation of the hypodermic tissue when the hypodermic tunnel is prepared. Thus, delay of organization by the connective tissue of the second cuff can be prevented. Further, while since the second cuff is near the exit site, infection is apt to occur, the exit site infection can be prevented by the pre-organization by fixing of the cuff.
Further, in the catheter according to this invention, the portion in the vicinity of the first cuff toward the inside of the peritoneal cavity from the first cuff of the peritoneal cavity insertion portion is of a structure such that the restoring force of the tube is enhanced. Accordingly, the catheter tip migration by the intestine is difficult to occur.
In addition, even if such tip migration takes place, the catheter can be easily restored to the Douglas cavity.
Furthermore, in accordance with the catheter according to this invention, the hypodermic tunnel portion is bent in a loop form so as to take an inverse U-shape. The second cuff is disposed at the vertex of the loop, the first cuff is disposed at a position corresponding to the peritoneum, the first cuff is caused to be of a structure such that it can be fixed on the peritoneum, and the second cuff is caused to be of a structure such that it can be fixed on the abdominal rectus fascia.
Accordingly, fixing of that portion is securely carried out.
Healing of wound can be expected at an early stage.
Moreover, since down growth of the catheter exit site is early completed after operation, patients can take a bath and there result both less exit site infection and less hypodermic tunnel infection.
Further, the catheter of this invention takes, from the beginning, a form which is to be taken at the time when implantation is completed. In addition, the catheter is of a structure such that it is fixed in a good stable state at two ~1~2488 portions of the first cuff and the second cuff. Accordingly, there is hardly drainage failure fatal to CAPD, resulting in high reliability catheter.

Claims

What is claimed is :

1. A catheter for CAPD in which a hypodermic tunnel portion is provided at the intermediate portion of a tube formed with a soft material having human body compatibility, one leg portion thereof is caused to serve as an external extension portion, the other leg portion thereof is caused to serve as a peritoneal cavity insertion portion having suction/drain holes, a first cuff is provided at the boundary between the hypodermic tunnel portion and the peritoneal cavity insertion portion, and a second cuff is provided with a suitable spacing therefrom at the hypodermic tunnel portion, characterized in that the hypodermic tunnel portion is bent in a loop form to take an inverse U-shape, the second cuff is disposed at the vertex of the loop, and the first cuff is disposed at a position corresponding to the peritoneum.

2. A catheter for CAPD as set forth in claim 1, wherein the portion in the vicinity of the first cuff toward the inside of the peritoneal cavity from the first cuff of the peritoneal cavity insertion portion in the cateter for CAPD is of a structure such that a restoring force of the tube is enhanced.

3. A catheter for CAPD as set forth in claim 1 or 2, wherein the tube thickness is caused to be great over a predetermined length of the tube toward the inside of the peritoneal cavity from the first cuff of the peritoneal cavity insertion portion in the catheter for CAPD to enhance the restoring force.

4. A catheter for CAPD as set forth in any one of claims 1, 2 and 3, wherein the second cuff of the hypodermic tunnel portion in the catheter for CAPD is provided at the vertex of the loop bent in an inverse U-shape to reinforce it.

5. A catheter for CAPD as set forth in any one of claims 1, 2, 3 and 4, wherein the hypodermic tunnel portion is bent in a loop form so as to take an inverse U-shape, the second cuff is disposed at the vertex of the loop, the first cuff is disposed at a position corresponding to the peritoneum, the first cuff is caused to be a structure such that it can be fixed on the peritoneum, and the second cuff is caused to be a structure such that it can be fixed on the abdominal rectus fascia.