Hydrocephalus Shunt With Two-way Flushing Means

Abstract

Drainage devices for use such as ventriculo-atrial shunts are provided which are particularly useful in neurosurgery to divert fluid from the cerebral ventricular system when abnormal collections of cerebrospinal fluid occur secondary to obstruction or failure of reabsorption. The surgical appliances of this invention have a first chamber and an at least partially surrounding second chamber with inlet means to the first and second chamber and outlet means from the second chamber. A valve means allows entrance of fluid to the first chamber from the inlet means but prevents backflow of fluid to the inlet means from the first chamber while allowing backflow of fluid from the second chamber to the inlet means.

Parent Case Text

RELATED APPLICATION

This application is a continuation-in-part of copending application Ser. No. 549,517 filed May 12, 1966 and now abandoned.

Description

BACKGROUND OF THE INVENTION

Ventriculo-atrial shunts have been used in neurosurgery in the past. Such shunts are particularly useful in the treatment of hydrocephalus which most frequently occurs in young children. In this condition, fluids secreted by the brain collect in the lateral ventricle of the brain and exert considerable pressure which can cause distortion of the ventricle and in some cases, distortion of the skull along with attendant unwanted effects on an individual. Common neurosurgical procedure now alleviates hydrocephalous conditions by surgical implantation of a shunt which carries excess fluids from the ventricle of the brain to the venous system where the foreign fluids are eventually absorbed and/or eliminated as through the kidneys.

Conventional drainage or shunt devices for use in alleviating hydrocephalus include those disclosed in U.S. Pat. No. 3,020,913 and U.S. Pat. No. 3,111,125. These devices are often implanted in a burr in the skull by a surgical operation. Devices of the type disclosed by the patents are extremely useful but have certain limitations. After implantation and use over extended time periods, such devices tend to become clogged in certain individuals. Such clogging tends to occur at the catheter or passageway from the ventricle of the brain leading into inner chambers of the devices due to foreign materials which collect in the narrow tubular passageways and at their openings to the drains. Consequently, it is often necessary to perform second or subsequent operations on an individual to remove devices which have become clogged. The inconvenience, cost and physical and psychological problems involved in performing such additional operations are considerable.

SUMMARY OF THE INVENTION

An important object of this invention is to provide a drainage device for use as a medical shunt which is highly effective in alleviating hydrocephalus and other conditions.

Another object of this invention is to provide a drainage device in accordance with the preceding object which permits flushing and cleaning of all portions thereof without the necessity of removing the shunt from the body once implanted.

Still another object of this invention is to provide a drainage device in accordance with the preceding objects which permits injection or aspiration of materials for cleaning, treating or diagnostic purposes.

According to the invention a drainage device comprises a ventriculo-atrial shunt having a means defining a first chamber with an outlet passageway and an inlet passageway. A second chamber is provided with an inlet means defining a first opening for passing fluids to the first chamber and a second opening for passage of fluids to the second chamber. Valve means are provided for permitting passage of fluids to the first chamber from the inlet means and preventing backflow of fluids to the inlet means without closing the second opening. Preferably the valve means is a one-way flap valve lying within the first chamber and operative to close the inlet passageway and the second chamber completely surrounds the first chamber.

In an alternate embodiment of this invention, the second chamber surrounds only a portion of the first chamber.

It is a feature of this invention that the drainage device is useful in introducing drugs into the brain for tumor chemotherapy, fighting infection or other purposes. Thus, the second chamber can be used both to alleviate clogging problems by aspiration and to introduce materials in a backflow through the inlet means.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the present invention will be better understood from the following detailed description of a preferred embodiment thereof when read in connection with the accompanying drawings in which:

FIG. 1 is a pictorial illustration of a preferred embodiment of this invention implanted in a young child;

FIG. 2 is an enlarged perspective view thereof;

FIG. 3 is a cross-sectional view through a central vertical plane thereof;

FIG. 4 is a cross-sectional view taken through line 4-4 of FIG. 3;

FIG. 5 is a top plan view of an alternate embodiment thereof; and

FIG. 6 is a cross-sectional view through line 6-6 of FIG. 5.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS

With reference now to the drawings and more particularly FIG. 1, a drainage device or ventriculo-atrial shunt 10 is shown with an inlet tube 11 acting as a catheter positioned in the lateral ventricle of the brain in accordance with known practice. The outlet passageway formed by the tube 12 is interconnected with the venous system of the body and preferably the jugular vein of an individual in accordance with known practice. Thus, cerebrospinal fluid can be drained from the ventricle of the brain as pressure builds up and passed through the shunt 10 to the blood system as is known in the treatment of hydrocephalus.

The drainage device 10 has an inner chamber 13 formed by a preferably flexible rubbery material such as silicone rubber or natural gum. Silastic, a trademark product of the Dow-Corning Company is preferred for use in all of the members of the device 10. The chamber wall 14 is preferably rounded and has the form of a flattened sphere although other shapes may be used if desired. Chamber 13 is opened by its interconnection with the outlet catheter 12 and the inlet catheter 11 as best shown in FIG. 3. Preferably a portion of the wall 14 is thickened at 15 to prevent unwanted puncture of the wall 14 during aspiration or injection as will be later described.

A flap valve 16 is provided opening inwardly into the chamber 13 and providing for one-way passage of fluids from the ventricle into the chamber while preventing passage of fluids out of the chamber towards the ventricle. The flap valve 16 may be a simple thin rubber flap adhesively or otherwise secured to the inner surface of wall 14 as suggested in FIG. 3. The one-way flap valve is preferred for use although other known one-way valves can be used if desired.

Completely surrounding the chamber 13 is a second chamber 17 formed by a wall 18 preferably of the same material as the wall 14 and dimensioned slightly larger than the dimensions of wall 14 to provide an adequate space between the two walls. The chamber 17 acts as a collection chamber in use and tends to accumulate any solid particles carried by the fluid into the device 10.

The inlet catheter 11 is joined directly to the wall 18 of the second chamber and has an upper end 19 connected to the wall 14 of the chamber 13. Preferably at least two orifices 20 are provided about the circumference of portion 19. The portion 19 and plural orifice end portion 24 of the catheter 11 are normally the locations where clogging and accumulation of foreign particles occur in normal use of the shunt 10. However, since the orifices 20 are provided, many of the particles that would normally tend to clog the catheter 11 are passed into the chamber 17 in use or flushed back into the ventricle of the brain.

In use of the double chambered ventriculo-atrial shunt 10, cerebrospinal fluids pass through the catheter 11 and a portion of the fluids is passed to the chamber 17 as indicated by the directions arrows 21. As soon as the chamber 17 is filled, additional fluids which tend to build up slight pressures pass through the flap valve 16 into the chamber 13 and from there onto the venous system through the outlet catheter 12. If the pressure differential between the fluid in the ventricle and that in the venous system to which the device 10 is attached should equalize or the venous system pressure should exceed that of the ventricle fluid pressure, flap valve 16 closes preventing backflow as does a conventional slit valve (not shown) at the distal end of catheter 12. On the other hand, in normal operation, flow through is easily accomplished due to the normally small pressure differential forcing fluids towards the venous system. If a reversal of normal pressure is encountered, the wall 14 of chamber 13 can be used as a pump. Since the device is normally positioned in a burr in the skull underlying the skin, finger pressure can be exerted at the thickened portion 15 to aid in desired flow through the shunt. Moreover, a finger pressure can be exerted at preselected intervals to flush the outlet tube by causing a rapid surge of relatively high-pressure fluid.

The shunt 10 can be periodically cleaned without removal from the body by inserting a hypodermic syringe into the chamber 17 through the skin of the individual in which it is implanted and through self-sealing wall 18 and aspirating the chamber thereby cleaning the chamber and removing any particles that might tend to have accumulated particularly at the portion 19. It is an important feature of this invention that aspiration of the chamber can be accomplished while the flap 16 is closed. In certain cases it is preferred to slightly depress the wall 14 during aspiration to assure closing of the valve. In addition, since a hypodermic needle can readily penetrate the wall of chamber 17, various medicaments can be introduced into this chamber with sufficient back pressure to directly irrigate and carry the medicaments to the ventricle for treatment of infections, cancer or various other disorders. Preferably injection or aspiration is accomplished by having the hypodermic needle penetrate the area directly above the portion 15 with the thickened portion 15 aiding in assuring that the point of the needle enters only chamber 17 and does not pass through to the chamber 13. It is also possible to introduce a hypodermic needle into chamber 13 if desired to add treating medicaments or suitable additives to aid in flushing and cleaning the catheter 12.

Preferably the walls 18 and 14 are flexible, resilient rubbery materials as previously described. Such materials are selected to be self-sealing after puncture by conventional hypodermic needles. The size and dimensions of the walls and passageways may vary considerably depending upon the age of the individual into which the shunt 10 is to be surgically implanted, as well as its specific usage. Preferably molded bosses 22 and 23 are provided on walls 14 and 18 to prevent collapse of chambers 17 and 13 respectively.

In a specific example, silicone rubber materials were used in all portions of the shunt. The overall dimensions of the shunt 10 were such that it fits into a burr hole of approximately 15 to 20 millimeters diameter. Flap 16 had a thickness of approximately 0.005 inch, catheters 11 and 12 had 1/16-inch diameters and 1/64-inch wall thicknesses, orifices 20 had diameters of about one sixteenth inch. Thickened wall portion 15 was approximately twice as thick as the remainder of wall 14 which had an overall thickness of about 0.03 inch as did wall 18. The axial length of portion 19 is approximately one twelfth inch.

Turning now to an alternate embodiment of the invention, a ventriculo-atrial shunt 30 is shown in FIG. 5 which is generally similar to the device 10 described above. However, in the device 30, the second chamber only partially surrounds the first chamber.

As best seen in FIG. 6, the drainage device 30 defines an inner chamber 33 having a flat bottom 35 and a hemispherical wall 34 covered by a second chamber 37 defined by a hemispherical wall 36. The first chamber has an outlet passageway 32 formed by a flexible tube sealed from the second chamber 37 and generally identical to the outlet passageway 12 of FIG. 3. The inlet passageway 44 is formed by a flexible inlet tube 11' having a first opening 38 and at least one second opening 39 between the tube passageway and the second chamber 37. Preferably a plurality of orifices 39 are provided opening to the second chamber 37 as previously described with reference to orifices 20.

The inlet passageway to the first chamber 33 has a valve means 40 as shown in FIG. 6 and can comprise a sievelike plate 41 having a plurality of openings 42 to the inner chamber 33. A flap 42a for the valve permitting movement of fluid only in the direction of arrows 43 is provided. Other types of valves can be substituted for the flap valve. For example, a stainless steel valve seat can be molded onto the device and a lightweight ball as of a nonmetallic plastic such as Teflon can be utilized in place of the flap.

The device 30 is generally identical to the device 10 in that thickened portions 15 can be provided in the wall 34 and spacers 22 can be provided where desired with walls of the device being made of a rubbery material as previously described to permit flexing of the walls when desired.

While a specific example of this invention has been described in detail, it should be understood that many variations thereof are possible. In all cases, it is important to have the double chambers which act as a pump to provide a separate chamber or passageway that bypasses the valve. The specific dimensions of the components can vary greatly and the specific positioning and attachment of catheters 11 and 12 can be varied to suit specific applications as is known in the art. In some cases, portions of walls 14 and 18 can be relatively rigid although flexible materials are preferred. The ventriculo-atrial shunt of this invention is useful in a variety of shunting applications in the medical field.

In view of the many variations possible, this invention is to be limited only by the spirit and scope of the appended claims.

Claims

What I claim is:

1. A drainage device for use as a ventriculo-atrial shunt comprising, means defining a first chamber having an outlet passageway and an inlet passageway,

means defining a second chamber surrounding said first chamber,

an inlet means defining a first opening for passing fluids to said first chamber,

said inlet means defining a second opening to said second chamber,

and valve means for permitting passage of fluids to said first chamber from said inlet means and preventing backflow of fluids to said inlet means without closing said second opening.

2. A drainage device for use as a ventriculo-atrial shunt in accordance with claim 1 wherein said inlet means comprises a tube interconnected with said first chamber at one end and with said second chamber at a point axially spaced from said one end and defining orifices for passage of fluids to said second chamber and first chamber.

3. A drainage device for use as a ventriculo-atrial shunt in accordance with claim 1 wherein said means defining said first chamber and said means defining said second chamber are composed of a flexible, self-sealing rubbery material and said valve means is a one-way flap valve positioned within said first chamber and operative to close said inlet passageway.

4. A drainage device for use as a ventriculo-atrial shunt in accordance with claim 1 wherein said inlet means comprises a tube defining orifices positioned within said second chamber.

5. A drainage device in accordance with claim 1 and further comprising means for preventing collapse of said first and second chambers.

6. A drainage device for use in a living body comprising

means defining a first chamber and formed of a flexible, rubbery material,

means defining a second chamber and formed of a flexible, rubbery material,

said second chamber being positioned overlying and in contact with said means defining said first chamber,

inlet means for passing fluid to said first and second chambers,

outlet means for passing fluid out of said first chamber,

and valve means in fluid communication with said inlet means for allowing entrance of fluid to said first chamber from said inlet means but preventing backflow of fluid to said inlet means from said first chamber while allowing backflow of fluid from said second chamber to said inlet means.

7. A drainage device for use as a ventriculo-atrial shunt comprising,

first flexible means defining a first chamber having an outlet passageway and an inlet passageway,

said first flexible means comprising a wall,

second flexible means defining a second chamber overlying said first chamber with said second chamber defined in part by said wall,

an inlet means defining a first opening for passing fluids to said first chamber,

said inlet means defining a second opening to said second chamber,

and valve means in fluid communication with said first opening permitting passage of fluids to said first chamber from said inlet means and preventing backflow of fluids to said inlet means from said first chamber without closing said second opening to said second chamber.

8. A drainage device for use as a ventriculo-atrial shunt in accordance with claim 6 and further comprising said valve means being a one-way flap valve lying within said first chamber and operative to close said inlet passageway.

9. A drainage device for use as a ventriculo-atrial shunt in accordance with claim 7 wherein said second flexible means defines said second chamber lying partially surrounding said first chamber, and said first and second flexible means are formed of self-sealing rubber.

10. A drainage device for use as a ventriculo-atrial shunt in accordance with claim 9 wherein said second flexible means defines said second chamber completely surrounding said first chamber.

11. A drainage device for use as a ventriculo-atrial shunt comprising, means defining a first chamber having an outlet passageway and an inlet passageway,

means defining a second chamber with said second chamber surrounding at least one surface of said first chamber,

an outlet means from said first chamber for removing fluid from said first chamber through said outlet passageway,

an inlet means for passing fluids to both said first and second chamber,

and valve means in fluid communication with said inlet means for permitting passage of fluids to said first chamber from said inlet means through said second chamber but preventing backflow of fluids from said first chamber to said second chamber while simultaneously not obstructing backflow of fluids from said second chamber to said inlet means.

12. A drainage device in accordance with claim 11 wherein said second chamber completely surrounds said first chamber.

13. A drainage device in accordance with claim 11 wherein said means defining said first chamber and said means defining said second chamber include a common wall.

14. A drainage device in accordance with claim 11 wherein means defining said first chamber and said means defining said second chamber are formed of flexible self-sealing material.

15. A drainage device in accordance with claim 14 wherein said means defining said first chamber and said means defining said second chamber include a common wall,

said outlet means comprising a tube passing through said second chamber.

16. A method of relieving fluid pressure in a ventricle by the use of a drainage device having an inlet means, a second chamber about overlying a first chamber, a valve means in said first chamber and an outlet means from said first chamber leading to a distant area, said method comprising,

positioning said drainage device with said inlet means in said ventricle,

passing said fluid through said inlet means to said second chamber and collecting foreign materials in said second chamber if present in said fluid,

passing said fluid to said first chamber and through said outlet means,

and subsequently applying pressure to said second chamber and simultaneously to said first chamber through said second chamber to flush said second chamber through said inlet means and to activate said valve means to prevent backflow of fluid from said first chamber to said inlet means.

17. A drainage device in accordance with claim 1 wherein said means defining said first chamber and said means defining said second chamber are each formed of a flexible, self-sealing rubbery material.