Telescoping Shunt System For Physiological Fluid

Abstract

This invention relates to an auxiliary device for use with and in physiological shunt circuits for the drainage of unwanted fluids from one part of the body to another. According to this invention a telescopic section is incorporated into a shunt catheter so that when one end of the system is implanted in an area of the body to be drained (such as the ventricles of the brain) and the other end of the system is implanted in a portion of the body into which the fluid must be drained (such as the heart), then, when there is bodily growth which would require elongation of the system, the telescopic portion will elongate and thus prolong the period before the system or some part of it must be replaced to compensate for normal growth. The catheter incorporating the telescopic section is made in two segments having flanged ends which contact the inside of a silicone rubber cylinder and are fluidtight, but can move longitudinally under tensile loads applied as a consequence of the growth of the child. The flanged ends may be radiopaque in order that the elongation may be checked by X-ray. These ends are held against withdrawal.

Description

This invention relates to auxiliary devices for use in physiological shunt circuits.

The drainage of fluid from one part of the body where it is unwanted to another from which it can be disposed of by providing a shunt passage for the fluid is well known. An example of a catheter for such a purpose is shown in U.S. Pat. No. 3,020,913 to Heyer.

In the usage of such catheters (sometimes called "shunts"), auxiliary means are often provided for supplemental functions. An example of one such auxiliary means is shown in U.S. Pat. No. 3,111,125 to Schulte. In this patent, a lozenge is combined with a shunt, which lozenge, while permitting unimpeded flow therethrough and through the shunt, is also actuable as a pump for aiding the expulsion of the fluid, to act as a check valve, and to test the openness of the upstream end of the system.

It is an object of this invention to provide new and additional auxiliary means between the region to be drained and the receiving region for the drained fluid in individuals subject to growth so as to permit the shunt system to elongate with the growth of the individual, thus prolonging the period before such shunt circuit may have to be removed and replaced with a longer mechanism. This further results in a new system with improved properties over prior art systems.

A further object of the invention is to provide means in a telescopic catheter which permits the use of radioscopy to determine the extension of the telescopic section, and thus to determine whether the function of the element has been fully expended.

Still another object of the invention is to provide means on one end of the catheter to prevent too-easy withdrawal of the tube, thus aiding it in exerting a tensile load upon the telescopic portion and thereby providing elongation.

The above and other features of this invention will be fully appreciated from the following detailed description and the accompanying drawings in which:

FIG. 1 shows the presently preferred embodiment of the invention in the body of a child;

FIG. 2 is a cross section of a portion of the invention shown in Fig. 1, taken at line 2--2 therein; and

FIG. 3 is a cross section taken at line 3--3 of FIG. 2.

A telescopic catheter 10, as shown in FIG. 1, is incorporated in a shunt system, and is fixed to the body at a location between the two ends of one arm of the system (the arm sometimes herein called a "drainage catheter"), which arm is divided into two adjacent portions in this device.

The portions of the drainage catheter are called the proximal catheter 11 and the distal catheter 12. As seen in FIG. 2, the proximal catheter 11 and the distal catheter 12 have enlarged cylindrical flanges 13 and 14 which act as pistons and make a sliding sealing fit inside of retainer sleeves 15 and 16. Flanges 13 and 14 may be made radiopaque by applying a coating of, or by impregnation with, radiopaque material such as barium sulphate in order to visualize the flanges to X-ray in the implanted device.

The drainage catheter has a central passage and an outlet port from it, which outlet port is placed in a region such as the atrium of the heart, into which unwanted fluid is to be drained. A check valve of the slit-type shown in the said Heyer valve, or of any other type, may be included in the drainage catheter. The outer ends of the retainer sleeves overhang the outer faces of the flanges so as to hold them inside the retainer sleeves. Preferably the outer ends make a close fit with the outer walls of the catheter portions. An outer sleeve 17 encases the retaining sleeves 15 and 16. The three sleeves may be held assembled by an air-curing silicone rubber cement. All sleeves and the catheter tubes 11 and 12 may conveniently be made of silicone rubber.

In use in a shunt system another catheter 18 (sometimes herein called a "drainage catheter") is implanted so as to drain a region having unwanted fluids, such as the ventricles of the brain in cases of hydrocephalus. This catheter has a central passage and openings thereinto so as to collect fluid from this region.

A clearing pump in the shape of a lozenge 19 is sutured in position in a cavity in the cranium. This is preferably but not necessarily the pump and check valve of the said Schulte patent. The drainage and collection catheters meet at the pump, which interconnects them.

The proximal catheter portion 11 is sutured to the lozenge 19, which fixes its free end. Retainer sleeve 16 is sutured to the jugular vicinity by attachment of a suture to a groove 19a provided for that purpose, this suturing being done at the entry to the vein. The free end 20 of the distal catheter 12 is imbedded in the superior vena cava. Small irregularities 21 in the nature of protrusions are formed on the surface of the free end 20, and these will become encased in fibrous tissue in the superior vena cava, and thereby prevent too-easy withdrawal therefrom.

The telescopic portion of the catheter assembly is assembled by slipping the retaining sleeves 15 and 16 over the distal and proximal segments of the catheter so that the reduced portions 22 and 23 closely engage the outer diameter of the catheter, while the cylindrical enlarged flanges 13 and 14 of the catheter tubes 11 and 12 are in sliding, fluid-sealing fit with the inside walls of the retaining sleeves 15 and 16. The outer sleeve 17 is then slipped over the retaining sleeves 15 and 16 and cemented into place with an air-curing silicone rubber cement, thus holding the telescopic catheter parts assembled in proper relative position.

In use, with the distal and proximal segments of the catheter fixed to the clearing pump and to the jugular vein, and with an end embedded in the vena cava and retained by the protrusions' engagements with fibrous material, growth of the child will place a tensile load on the proximal and distal portions of the catheter, thereby causing the cylindrical flanged ends 13 and 14 to slip apart within the retaining sleeves 15 and 16. The position of the flanged ends 13 and 14, because of their radiopaque properties, enables the physician to X-ray the child and determine how much movement has occured within the telescopic portion of the catheter, and how much growth remains to be allowed before the device must be replaced with longer catheter portions.

The flanges are held against removal by the reduced portions 22 and 23, which are smaller than the flanges, so the device cannot be disassembled by an axial pull.

This telescopic joint markedly improves the function of the system and provides a feature of growth not heretofore available. It is, however, useful apart from pumps and check valves, for example, in a single-line shunt such as shown in the Heyer patent, wherein no pump is used.

The device is easily manufactured, and elegant in concept. It reduces the number of operations to which a person must be subjected. The importance of this should not be underestimated. It happens often that a new catheter cannot be inserted in the same jugular vein in which an "outgrown" catheter had been encased. Then the other jugular or another vein must be used. Obviously the choice of sites and frequency of the procedure are thereby circumscribed and the surgeons alternatives are limited. This invention restores some of these by reducing the frequency of the event.

The operation of the device is obvious. Sealing between two silicone rubber surfaces is a regular and routine matter. If desired, one may be made a bit more flexible than the other but this is not essential. The material is dimensionally stable, and once the seal has been tested, the reliability of the function may be assumed.

Claims

I claim:

1. A catheter for use in a physiological fluid shunt system, said catheter comprising: a first and a second tubular catheter portion, said tubular catheter portions each having an enlarged cylindrical flange; a pair of tubular retaining sleeves, each of said tubular retaining sleeves having a cylindrical inner wall with a reduced end adapted to overhang and retain against removal a respective one of said flanges and to make a close engagement with the outer wall of the respective catheter portion, said flanges making a sliding fluid-sealing fit with respective inner walls of said retaining sleeves; and an outer sleeve, said outer sleeve being bonded to and joining together and fluidly sealing the retaining sleeves, the retaining sleeves projecting beyond the ends of the outer sleeve.

2. A catheter according to claim 1 in which a groove is provided in the outer wall of one of said retainer sleeves to provide a point of attachment for a suture.

3. A catheter according to claim 1 in which one of said catheter portions carries protrusions on its surface near its end away from the sleeves, said protrusions being adapted to engage with fibrous body materials to prevent too-easy withdrawal.

4. A catheter described in claim 1 in which said enlarged shoulders on said tubular catheter segments are radiopaque.

5. A catheter according to claim 1 in which said tubular catheter, said retaining sleeves, and said sleeves are made of silicone rubber.

6. A catheter according to claim 3 in which said enlarged shoulders on said tubular catheter are radiopaque, and in which the catheter and said sleeves are made of silicone rubber.

7. A physiological fluid shunt system which comprises: a collector catheter; pump means draining fluid from said collector catheter; a drainage catheter receiving fluid from said pump means, said drainage catheter having a first portion and a second portion, and a telescopic coupling means connecting said portions for enabling the length of the drainage catheter to increase, said telescopic coupling means comprising: an enlarged cylindrical flange on each of the catheter portions; a pair of tubular retaining sleeves, each of said tubular retaining sleeves having a cylindrical inner wall with a reduced end adapted to overhang and retain against removal a respective one of the said flanges and to make a close engagement with the outer wall of the respective catheter portion, said flanges making a sliding fluid-sealing fit with respective inner walls of said retaining sleeves; and an outer sleeve, said outer sleeve being bonded to and joining together and fluidly sealing the retaining sleeves, the retaining sleeves projecting beyond the ends of the outer sleeve.

8. A system according to claim 7 in which a groove is provided in the outer wall of one of said retainer sleeves to provide a point of attachment for a suture.

9. A system according to claim 7 in which one of said catheter portions carries protrusions on its surface near its end away from the sleeves, said protrusions being adapted to engage with fibrous body materials to prevent too-easy withdrawal.