Catheter

Abstract

A catheter for use in an animal or human body. A flexible tube resistant to the action of body fluids and compatible with the body environment, e.g., of silicone rubber, has an exterior portion, an interior portion, and a percutaneous or skin-passing portion. The interior portion has apertures for withdrawal of fluid from a body cavity or vessel; the exterior portion has a removable closure. The skin-passing portion has a fabric or textile skirt or annular flange that lies adjacent the inner surface of the epidermis of the animal bearing the catheter. If desired, the skin-passage portion of the catheter is also provided with a fabric or textile sleeve. The fabric or textile is advantageously of Dacron or of Teflon or of like material not attacked by and compatible with the body environment.

Description

This invention relates to an improved catheter. Various problems have been encountered in the treatment of kidney disease, e.g., of chronic renal failure, by maintenance hemodialysis or by peritoneal dialysis. In hemodialysis, poor stabilization of the cannula, infections, and ineffective handling of or inability to remove clots forming at the site of treatment have led to failures of the devices. In peritoneal dialysis, infection or peritonitis has been a major problem. In one catheter means intended to reduce or prevent infection, a relatively long subcutaneous portion of the catheter lay between the skin and the peritoneum and then the tube was inserted through the peritoneum into the abdominal cavity; but this structure tended to cause discomfort to many patients and provided a quite circuitous route for fluid passage. Also, cleaning of the lumen of such a catheter to remove fibrin plugs, etc., which may form, has been difficult if not impossible.

There has been, therefore, a great need for a straight line, permanent catheter installation for peritoneal dialysis. There has also been a great need for a permanently affixed cannula of that which can be held in position with respect to a blood vessel, vein, or artery, into which it enters. For instance, the external motion occurring when attaching the patient to an artificial kidney has been transmitted in many instances in prior art cannulas to the cannula-vessel junction and caused repeated trauma to the vessel at the cannula tip.

It is important to stabilize the cannula in order to prevent rotational motion and malalignment. In peritoneal catheters it is important to have a permanent device in order to avoid repeated incisions, and to avoid bleeding and leakage around the catheter, which has sometimes been troublesome in peritoneal dialyses done according to the prior art.

These and other objects are attained by the present invention, as will be evident from the description below.

The improved catheter of this invention is used for withdrawing fluids from animals bodies or cavities therein, and it comprises a flexible tube provided with a plurality of apertures or holes adjacent one end and closure means at its outer end. A skirt or annular flange of suitable textile material or cloth is disposed between the two ends of the tube and is adapted to lie adjacent the inner surface of an animal or human skin when installed. If desired, a cloth or textile sleeve is also attached to the outer surface of such tube, suitably extending from the skirt or flange to the inner surface of any internal membrane through which the tube passes, such as the peritoneum.

The tube is made of a material compatible with the body material into which it is to be inserted, that is, a material not attacked by body fluids or the like and it is not irritating to the body. A preferred material is a silicone rubber, and such a material is available in commerce under the trademark Silastic, made by Dow Corning Corporation in a good medical grade.

The skirt or annular flange is disposed between the two ends of the silicone rubber tube, and its location depends upon the site at which the tube is to be inserted. For instance, if the tube is to be inserted into the peritoneum, a longer internal portion of the tube will lie within the abdominal cavity; whereas if the tube is to be inserted into a vein or artery, the internal length of the tube will be relatively shorter; the skirt is positioned to lie just beneath the skin of the animal or patient in either event. A sufficient length of tube lies outside the skin to enable manipulation, as that employed in attaching the tube to a dialysis machine, in inserting bougies or the like for cleaning or declotting, etc. The skirt is of a cloth or textile material, and it has pores or spaces into which fibrous tissue can grow when the skirt is emplaced within the body, thereby enabling fixation to the skin layer. This material also is so chosen as to be nonirritant and not attached by the body components. A very suitable material is poly(ethylene terephthalate), available in commerce under the trademark Dacron, made by E. I. du Pont de Nemours & Co., and the material used will be referred to hereinafter by the name Dacron, with the understanding that other such compatible materials are useful in this invention. The annular flange or skirt is preferably of one layer of textile; and is of suitable width to underlie the incision required for entry of the tube and to extend a reasonable distance outwardly therefrom to insure good affixation upon growth of tissue. For instance, on a catheter of about 1/4-inch outside diameter, a suitable skirt has a diameter of about 13/4 inches. Another suitable material for the skirt is polymerized tetrafluoroethylene, available in commerce under the trademark Teflon, as made and sold by E. I. duPont de Nemours & Co. A mesh or webbing material is particularly effective in the skirt of the present invention because it allows readily for growth and penetration of the fibrous tissue developed by the body, and it is strong, maintaining the catheter or cannula in position for extensive periods of time.

The tube is preferably open at both ends, having a cap or removable closure means at the outer end, and also having holes or apertures at the interior end to facilitate flow and withdrawal of body fluid. Such apertures are advantageously placed over about half the length of the portion of the tube lying within the abdominal cavity, and in one advantageous embodiment are arranged in staggered row, about 4 mm. on center. In one satisfactory embodiment, the holes have been round and of 0.030-inch diameter. However, the number size and position can be varied as desired. In a cannula it is usually sufficient to have just the open inner end of the tube disposed within the blood vessel being treated, but this also can be varied as desired. The suitable sizes of the catheters and cannulas are those well known to the art and form no part of this invention.

In a series of experiments with rabbits, Silastic rods were implanted under anesthesia in the abdominal wall; in 34 of these implantations, the rod was provided with the cloth skirt of this invention, and in 16 others the skirt was omitted. The rods with skirts showed progressive fixation and maturation of fibroblasts, and infection was not seen grossly nor microscopically. The implanted rods without the skirts were freely mobile, with no sign of fixation, and one-half of this group of animals exhibited gross and microscopic infection at the end of the 4 weeks test. Microscopic fibroblastic activity was not seen.

The subcutaneous fixation obtained by the present invention enables the use of straight subcutaneous cannulas. Declotting is facilitated in a straight cannula, because it enables the use of bougies and irrigating catheters past the cannula tip into the blood vessel. Flow-compromising curves in the curved and double curved, subcutaneous portion of conventional cannulas are eliminated with the straight cannula; and, in addition, cannula insertion is simpler with the straight cannula. Trauma to blood vessels at the cannula tip is avoided or reduced by the subcutaneous fixation of the present invention. Infection is lessened and daily cleaning around the cannula exit site has been found to be unnecessary or infrequently necessary in the devices of this invention.

The invention will now be described with reference to the annexed drawings.

In the drawings:

FIG. 1 is a view in elevation of a peritoneal catheter embodying the principles of the present invention.

FIG. 2 is a view in section of the catheter, taken on line 2--2 in FIG. 1.

FIG. 3 is a front view of the abdominal portion of a human patient, having the catheter of this invention in place.

FIG. 4 is an enlarged view in section through skin and peritoneum, taken on line 4--4 of FIG. 3, showing the placement of the catheter relative to the skin.

FIG. 5 is an exterior fragmentary view of a patient's limb showing the entry and placement of a shunt cannula embodying the principles of this invention.

It will be understood that the specific description of the embodiments shown in the drawing is for purposes of illustration only.

A peritoneal catheter 10 embodying the principles of this invention is shown in FIG. 1. It comprises a flexible Silastic tube 11 having an outer end 12, i.e., which will lie outside the patient's body when placed in position, an inner end 13 adapted to lie within the abdominal cavity, a connector piece 14 secured to the end 12, and a removable cap 15 over the connector piece 14. In this embodiment, the connector piece 14 is a rigid tube frictionally fitting into the end 12 of the silicone rubber tube 11 and partly maintained in place by slight indentations or inward bulges 16 in the tube 11; and the connector 14 is adapted to be connected to a dialysis machine. The cap 15 may be of rubber and closes and seals the end of the connector 14 and thus the outer end of the tube 11. The tube 11 has an intraperitoneal portion 17 provided with a plurality of small holes 18 at its innermost portion; in the drawing these holes extend over about 25 percent of the tube's length and are arranged in four staggered rows.

A Dacron open mesh skirt or annular flange 20 is affixed to the tube 11, suitably by Silastic Medical Adhesive, a cement that adheres to silicone rubber and also to Dacron and Teflon. The flange or skirt material is of mesh or webbing, providing many apertures to accommodate penetration and affixation by fibrous tissue growth when placed in a body.

Extending from the flange 20 toward the end portion 13 is, preferably, a textile sleeve 21, which in this embodiment may be of Dacron velour. The sleeve 21 extends from the skirt 20 along the tube 11 to the inner surface of the peritoneum 19 (See FIG. 4) and is lightly sutured to the peritoneum by sutures 22. The sleeve 21 is affixed to the tube 11 by means of a suitable medical adhesive, such as that mentioned above. The adhesive is suitably applied for a sufficient distance along the tube 11 to fill the interstices of the sleeve cloth, to prevent tissue growth thereinto. In many instances, the cloth sleeve 21 can be omitted.

As shown in FIG. 4, the skirt 20 is positioned to lie freely adjacent the inner surface 25 of the skin 24; and, in place, the catheter 10 extends straight through the skin and then through the peritoneum 19 into the abdominal cavity, by the shortest path. A great advantage of the present invention is that a minimal length of tubing is required, for thereby a minimal amount of foreign body is introduced into the patient's body; while at the same time the installation may be permanent, avoiding repeated incisions and reducing infection to a minimum, or eliminating it completely in some patients.

In placing the catheter 10 of this invention in a patient with chronic renal failure, the catheter 10 assembly is washed with bland soap, rinsed with running tap water, then in distilled water, and autoclaved in a stainless steel container. In an operating room and with the patient under general anesthesia, a lower abdominal transverse incision 26 is made below the intended catheter entry site. The catheter 10 is then brought through a stab incision 27 spaced from the original incision 26 and extending through the peritoneum 19; and the skirt 20 is positioned near the skin exit site. The cloth sleeve 21, where used, is sutured lightly to the inner face 23 of the peritoneum 19 by the sutures 22. The intraperitoneal portion 17 of the tube 11 is positioned to move freely in the peritoneal cavity. The incisions 25 and 26 are then closed.

In dialysis, which is suitably begun postoperatively immediately, the protective rubber cap 15 is removed, and standard commercial peritoneal dialysis tubing is attached to the catheter by means of the rigid plastic connector 14. At the completion of dialysis, the peritoneal dialysis tubing is disconnected, the plastic rigid connector 14 is then cleaned with 70 percent aqueous alcohol, and a sterile rubber cap 15 is placed over the connector end of the catheter.

It has been found that the patients need not clean around the catheter entry site between dialyses; and that catheters are not accidentally removed. No erosion of a skirt or flange through the skin has been found and in over 90 percent of the cases, no infection whatever occurred. Tissue fixation has been found to be good, the catheters not requiring special securing between dialyses; and in some cases, the patients can do the dialysis at home. In instances where fibrin has collected in the lumen of the catheter, it has been easily removed by irrigation or by passing a bougie or irrigating catheter through the peritoneal catheter. In the cannula shunt 30 shown in FIG. 5, a Dacron-Weaveknit skirt 31, 32 is adhesively attached to each of two cannula tubing 33, 34, at a position just subcutaneous to each skin exit site 35, 36, so that each skirt 31, 32 lies adjacent the inner surface of the skin surrounding the exit incision 35, 36. If desired, a cloth sleeve like the sleeve 21 can also be attached to each cannula body, extending from the skirt 31 or 32 to the innermost end 37 or 38 of each cannula body 33, 34, or such sleeve can be applied to only one of the cannula bodies, if desired. However, it is generally preferable to use the skirts 31, 32 without any such sleeve in this instance. To insert the cannula bodies, an incision 40 may be made under suitable anesthesia substantially midway between the blood vessels to be treated, and the cannula bodies 33, 34 drawn through incisions 35, 36, and the tip 37, 38 of each cannula 33, 34, is inserted into its respective blood vessel, the cloth skirts 31, 32 being positioned just beneath and adjacent the inner surface of the skin 41. The cannulas 33 and 34, each comprise a flexible outer portion 42, 43, and the rigid tips 37 38, respectively; and they are frictionally connected together by insertion of the end 44 of the cannula 34 into the end 45 of the cannula 33, in such a manner that the tubes are closed to the atmosphere. The connection can be disconnected at will to enable further shunting, e.g., through a dialysis or purification means, or the taking of samples, or for other purposes. The rigid tips 37, 38 are suitable of Teflon, and the flexible portions 42, 43 are suitably of Silastic, but other compatible, noneroding and sterilizable materials can be employed.

It has been found that the cannula installation is quite long-lived, and a great advantages is that with few exceptions, no gross or bacteriologically cultured infections have occurred, while at the same time it is not necessary for the patient to clean the exit site between dialyses, after the initial postoperative period. The cannulas are firmly secured in place in a short time with good resistance to pulling or rotational forces. However, if it is desired to remove the cannula, this can generally be done by gradually increasing the pulling force. If desired, removal can be facilitated by a suitable incision over the exit site. A further advantage of the cannula shunt of this invention is that declotting is facilitated in a straight cannula body because bougies and irrigating catheters can be easily passed through the straight cannula into the blood vessel.

The above specific description and drawings have been given for purposes of illustration only and it will be understood that variations and modifications can be made therein without departing from the spirit and scope of the invention. For instance, although the flange or skirt is illustrated a full annulus, a flange of less than a full circle can be used so long as it is sufficient to provide a good adhesion upon development of tissue growth after emplacement. Adhesive attachment of the skirt to the tube and of the sleeve to the tube is shown, but other means can be employed to affix these elements to each other as indicated.

Having now described the invention,

Claims

What is claimed is:

1. A tubular device for insertion through the epidermis of an animal or human body, including in combination:

a flexible tube compatible with and resistant to attack by animal body fluids,

a flexible fabric flange attached to said tube and adapted to be disposed adjacent the inner surface of said epidermis when emplaced, said flange being compatible with and resistant to attack by body fluids,

an interior portion of said tube adapted to extend into said body from said flange,

an exterior portion of said tube adapted to extend outwardly from said epidermis and having an open outer end,

means to close said outer end, and

a fabric sleeve, compatible with and resistant to attack by body fluids, encircling a portion of the length of said interior portion extending inwardly from said flange and being adhesively attached to the surface of said tube.

2. The tubular device as in claim 1 for insertion into and abdominal cavity, wherein said inner portion has an open inner end and is provided adjacent said end with a plurality of apertures.

3. The tubular device as in claim 1 wherein said flange is open mesh fabric.

4. The tubular device as in claim 3 wherein said fabric is poly(ethylene terephthalate).

5. The tubular device as in claim 3 wherein said fabric is polytetrafluoroethylene.

6. The tubular device as in claim 1 wherein said flexible tube is of silicone rubber and said flange is adhesively attached thereto.

7. The tubular device of claim 1 wherein said sleeve is of poly(ethylene terephthalate) and is adhesively secured to said tube.

8. A catheter for insertion into an abdominal cavity including a peritoneum, which comprises:

a flexible silicone rubber tube having an outer portion adapted to lie outside said cavity, and an inner portion adapted to lie within said cavity and said peritoneum when later emplaced,

said inner portion having an open end and a plurality of apertures disposed in rows adjacent said end and extending about one-fourth of the length of said tube, said outer portion having an open end, and

means for closing said open end of said outer portion,

a flexible annular flange of open-mesh fabric chosen from the group poly(ethylene terephthalate) and polymerized tetrafluoroethylene, adhesively attached to said tube and spaced from each of said ends, and

a sleeve of said open-mesh fabric encircling the portion of said inner portion proximal to said flange and extending to the inner surface of the peritoneum when emplaced, and being adhesively secured to said inner portion.

9. The catheter of claim 8 wherein a rigid plastic, sterilizable, tubular connector having an open end is affixed to said outer portion's open end and adapted to conduct fluid from said tube to a dialysis machine when in operation, and said means for closing comprises a sterilizable removable cap adapted to close said rigid connector.

10. A catheter for insertion into an abdominal cavity including a peritoneum, which comprises:

a straight flexible silicone rubber tube having two ends and an outer portion adapted to lie outside said cavity and an inner portion adapted to lie within said cavity and said peritoneum when later emplaced,

said inner portion having an open end and a plurality of apertures disposed in rows adjacent said end and extending about one-fourth of the length of said tube,

said outer end having an open end,

a flexible annular flange adhesively attached to said tube and spaced from each of said ends,

said flange being of open-mesh fabric chosen from the group poly(ethylene terephthalate) and polymerized tetrafluoroethylene,

a rigid plastic, sterilizable, tubular connector having an open end and affixed to said outer portion open end and adapted to conduct fluid from said tube to a dialysis machine when in operation,

a sterilizable removable cap adapted to close said rigid connector, and

a sleeve of said open-mesh fabric encircling a part of said inner portion extending inwardly from said flange to the inner surface of the peritoneum when emplaced, and being adhesively secured to that part of said inner portion.

11. A shunt cannula assembly adapted to withdraw and return blood from blood vessels disposed under the skin in an animal body, for hemodialysis, which comprises in combination:

a pair of straight flexible tubes,

each said tube having two open ends, an outer portion adapted to lie outside said skin and an inner portion adapted to lie under said skin,

said outer portions of said tubes being detachably connected together in open communication or through a purification means,

a flexible, annular fabric flange adhesively attached to each said tube and adapted to lie subcutaneously adjacent the inner surface of said skin, said flange being of open-mesh fabric chosen from the group poly(ethylene terephthalate) and polymerized tetrafluoroethylene, and

a sleeve of said fabric encircling one of each said inner portion inwardly of said flange.

12. The assembly of claim 11 having a rigid tubular tip portion disposed at the inner end of each said tube and having an open end, said tip being of polymerized tetrafluoroethylene.

13. A shunt cannula assembly adapted to withdraw and return blood from blood vessels disposed under the skin in an animal body, for hemodialysis, which comprises:

a pair of straight flexible silicone rubber tubes each having two open ends, an outer portion adapted to lie outside said skin, and an inner portion adapted to lie under said skin.

a flexible, annular fabric flange adhesively attached to each said tube and adapted to lie subcutaneously adjacent the inner surface of said skin, said flange being of open-mesh fabric chosen from the group poly(ethylene terephthalate) and polymerized tetrafluroethylene,

a rigid tubular tip portion disposed at the inner end of each said tube and having an open end, said tip being of polymerized tetrafluroethylene,

said outer portions of said tubes being releasable connected and sealed to each other in open communication, and

a sleeve of said fabric encircling the length of each said inner portion inwardly of said flange.