External ventricular drainage assembly

An external ventricular drainage assembly includes a ventricular drainage catheter which can be placed in the ventricles of a patient's brain and which is connected to a suture tab for securing the catheter to the patient and for preventing relative movement between the catheter and patient. A valve is connected to the catheter for selectively opening and closing the external ventricular drainage assembly to fluid flow. An adapter is connected to the valve for providing access to the fluid flow path within the assembly. A one-way valve is connected to the adapter. A first length of flexible tubing is connected to the one-way valve and is joined through a connector to a second length of flexible tubing. A collection reservoir is connected to the second length of flexible tubing and includes an entry and outlet port. A drip chamber is positioned between the second length of flexible tubing and the collection reservoir.

BACKGROUND OF THE INVENTION 
The invention herein relates to an external ventricular drainage assembly 
for use in the draining of cerebrospinal fluid (CSF) from the ventricles 
of a patient's brain to prevent the undue buildup of such CSF and pressure 
within the brain. 
The external ventricular drainage assembly herein is designed for use in 
the treatment of hydrocephalus wherein excess cerebrospinal fluid is 
drained from the ventricles of the brain. In many known techniques for the 
treatment of hydrocephalus, excess CSF is drained from the ventricles of 
the brain to another region of the body such as the right atrium or the 
peritoneum. In such systems, a valving mechanism is employed which is 
implanted in the patient. The valving mechanism permits the flow of the 
excess CSF from the brain to such other parts of the body. 
Under some circumstances, it is desirable to treat hydrocephalus by 
draining the excess CSF from the ventricles of the brain to a collection 
receptacle that is outside of the body. For example, surgically induced 
hydrocephalus may be only a temporary problem such that it would not need 
a totally implanted CSF shunting system. In such a case, an external 
drainage system is desirable. 
Problems associated with external drainage systems which drain fluid from 
the body, regardless of the fluid, generally relate to such systems 
providing routes of infection to the patient. An external drainage system 
which is open to the environment surrounding a patient can provide a route 
for microbes such as bacteria to enter the patient's body. It is 
undesirable to have the possibility for the introduction of bacteria to 
cause an infection to the patient as generally the patient is already in a 
weakened condition. It would be desirable to provide an external 
ventricular drainage assembly which would prevent or inhibit the 
introduction of bacteria and other microbes into the patient and which 
would be an easy to use system. 
SUMMARY OF THE INVENTION 
The external ventricular drainage assembly herein provides an assembly for 
draining excess CSF from the ventricles of a patient's brain to an 
external collection reservoir. 
The external ventricular drainage assembly herein includes a ventricular 
drainage catheter which can be implanted within the ventricles of a 
patient's brain and extends outside the patient's body. The catheter can 
be anchored to the patient through a suture tab to prevent relative 
movement of the catheter and patient. The catheter is connected to a valve 
which can open and close to permit or prevent fluid flow through the 
catheter and assembly. The valve can be a two or three ported stopcock. 
Connected to the valve is a Y-tube which includes an injection site. Also 
connected to the Y-tube is a one-way valve which permits flow of fluid in 
one direction, outwardly of the patient, through the assembly. The one-way 
valve is connected to a suitable length of tubing which in turn is 
connected to a second length of tubing through a connector. The connector 
consists of two parts which interconnect, providing fluid flow between the 
lengths of tubing. A tamper-evident closure can extend around the 
connector to show when the connector has been disconnected. 
Connected also to the second length tubing is a collection reservoir. The 
collection reservoir has an inlet which is connected to the second length 
of tubing through a drip chamber. The reservoir also includes an outlet 
for draining collected fluid. The outlet can include a withdrawal site 
whereby samples of collected fluid can be withdrawn from the reservoir, or 
whereby the collection reservoir can be emptied without opening the 
system. 
The collection reservoir can be appropriately marked with graduations 
indicating the volume of fluid collected and the height position of the 
collection reservoir relative to the patient.

DETAILED DESCRIPTION OF THE INVENTION 
With reference to the drawings, there is shown a working embodiment of an 
external ventricular drainage assembly which can be used to drain or 
transfer CSF from a patient to an external collection reservoir remote 
from the patient. The assembly can be used for either short term or long 
term transfer of CSF from the ventricles of a patient's brain to a 
collection reservoir for lowering the fluid pressure within the ventricles 
of the brain of the patient. 
With reference to the drawing, the external ventricular drainage assembly 
10 is shown. The assembly includes a drainage catheter 14 which can be a 
ventricular drain 12. The drainage catheter can be any suitable drainage 
catheter and generally has the structure of a catheter having apertures 
along a portion of its length for receiving CSF. The drainage catheter 
extends from the ventricles 13 outwardly of the skull of the patient 
through a suitable burr hole and along and under the scalp to an exit 
site. The catheter then extends outwardly from the patient. The catheter 
can be held in place to prevent relative movement of the catheter and 
patient by a suture tab 18. The suture tab can be sutured to the patient 
to prevent relative movement of the catheter. 
In some applications it is desirable to employ a catheter guide 16 for 
holding the catheter in position within the patient's brain. The catheter 
guide can also be fixed to the patient such as by suturing to the scalp. 
The catheter is connected to a valve 22. The catheter can be connected 
directly to the valve or can be connected through a catheter connector 20. 
The catheter connector 20 can be a connector which provides either a slip 
fit, twist lock, or screw-type connection to a port on the valve. 
The valve 22 can be any suitable valve which permits the opening and 
closing of the assembly to fluid flow. That is, the valve can be 
selectively positioned to permit CSF flow through the assembly or to 
prevent CSF flow through the assembly. Suitable valves can be a two port 
or three port stopcock as is shown in the drawing. In the drawing, the 
valve 22 is a three port stopcock with an inlet port 24 to which the 
catheter is connected, an outlet port 26, and a third port which can be a 
pressure monitoring port 28. Such a third port is desirable as it can 
permit the monitoring of fluid pressure within the assembly which in turn 
can be correlated to the fluid pressure within the patient's brain. A 
pressure transducer can be interconnected to such a pressure monitoring 
port 28 on the valve. 
Connected to the outlet port of the valve is an adapter for monitoring 
intracranial pressure such as Y-tube 30. The adapter includes an injection 
site 32. The injection site can be a self-sealing material which permits 
the insertion of a needle cannula for withdrawing a sample of the fluid 
within the assembly or injecting fluids into the brain. In some 
embodiments of the assembly, the injection site need not be on such an 
adapter. That is, a third port on a stopcock valve can be utilized as a 
sample port or can be equipped with an injection site for injecting fluids 
or withdrawing samples of the CSF. In such an embodiment, the outlet port 
of the valve can be directly connected to the next element which is a 
one-way valve 34. 
Also connected to the adapter 30 is a one-way valve 34. The one-way valve 
can be any suitable valve for permitting fluid flow through the assembly 
in one direction; i.e., outwardly of the patient. Suitable one-way valves 
include a miter valve as is shown in the drawing. 
Connected to the one-way valve is a first length of tubing 36. The first 
length of tubing can be of any sufficient length depending on the election 
of the end user and the desired placement of the drainage reservoir from 
the patient. Such a first length of tubing can be provided with a clamp 38 
which can, when its in its clamped position, close the tubing to fluid 
flow therethrough. Closing the clamp is a backup to the one-way valve to 
also insure fluids injected through injection site 32 are delivered to the 
brain. 
The first length of tubing is connected to a second length of tubing 42 
through a coupling 40. The coupling 40 can include two separate 
interconnecting elements each of which is respectively connected to the 
first and second lengths of tubing. The elements of the coupling interlock 
to provide a fluid-tight coupling between the first and second lengths of 
tubing. Extending around the coupling 40 can be a tamper-evident seal 41. 
The tamper-evident seal can be a stretch-fitted plastic band or other 
suitable material which can be adhered to the two elements of the 
coupling, such that when the elements of the coupling are disconnected, 
the disconnection shows by the rupturing or tearing of the tamper-evident 
seal. By providing a tamper-evident seal to the coupling, any opening of 
the coupling can be readily observed by the user. A clamp can be 
positioned along the second length of tubing for occluding the second 
length of tubing to fluid flow therethrough. 
The second length of tubing extends to and is connected to the collection 
reservoir 46. The collection reservoir 46 has an inlet port 50 which can 
be connected to the second length of tubing through a drip chamber 48. The 
drip chamber 48 can be useful in monitoring the flow rate of fluid through 
the assembly and can assist in the prevention or inhibition of bacteria 
migration through the assembly and to the brain. The reservoir can also be 
provided with an outlet port 52. The outlet port 52 can be equipped with a 
clamp for opening or closing the port to fluid flow. In the preferred 
embodiment of the assembly, the outlet port is provided with a withdrawal 
site 56. The withdrawal site can be a self-sealing material which permits 
the introduction of a needle cannula into the reservoir for obtaining a 
sample of the fluid therein or for emptying the collection reservoir. The 
withdrawal site reseals upon withdrawal of the needle cannula. 
The outlet port can include a length of tubing extending between the 
reservoir and withdrawal site which can be cut to remove the withdrawal 
site and thereafter be closed with a clamp 54. 
The preferred structure of the collection reservoir is as shown in the 
drawing. That is, the collection reservoir has a generally conical shape 
which permits ease of determining the volume of CSF collected. That is, 
for minor amounts of CSF collected the volume can be readily determined. 
The reservoir can be marked with graduations for determining the volume as 
is indicated in the drawing. 
The collection reservoir can include along its side graduation markings as 
are shown in the drawing. Such additional markings are useful in 
positioning the reservoir and in determining the height of the collection 
reservoir relative to the patient. By placing the desired height of the 
height scale at the same level as the catheter inside the patient, the 
fluid pressure within the ventricles will be maintained and will prevent 
any siphoning action. 
The external ventricular drainage assembly is useful in draining excess CSF 
from a patient. In operation, the ventricular drainage catheter is placed 
in the ventricles of the patient's brain, extended through a burr hole in 
the patient's skull and under a portion of the scalp of the patient, and 
exited through an opening in the scalp spaced from the burr hole. The 
catheter can be sutured to the patient's scalp to prevent relative 
movement. 
Excess CSF in the ventricles drains into the ventricular drainage catheter 
and through the valve 22. 
The valve 22 can be selectively positioned to permit the fluid to flow 
therethrough. In addition, the valve can be selectively positioned to 
permit monitoring through its pressure monitoring port of the fluid 
pressure within the assembly. 
The CSF flows through the valve and into and through the one-way valve 34. 
If it is desirable to inject fluid into the brain or to obtain a sample of 
the CSF from the assembly, this can be done through the injection site 32. 
That is, the cannula of a syringe can be inserted through the injection 
site to obtain a sample of the fluid or deliver fluid to the system. 
The CSF continues to flow through the one-way valve along the first and 
second lengths of tubing and drips through the drip chamber 48 and into 
the collection reservoir 46. The volume of CSF collected in the collection 
reservoir can be monitored by a doctor, nurse or attendant for the 
patient. It is possible to sample the CSF collected in the collection 
reservoir through the withdrawal site 56 by inserting a needle cannula of 
a syringe into and through the withdrawal site. It is also possible to 
obtain a sample by removing the withdrawal site and permitting the 
collected CSF to flow through the outlet port of the collection reservoir 
into a suitable receptacle. The collection reservoir can also be emptied 
through the withdrawal site by using a suitable needle cannula which can 
pierce the withdrawal site. 
In some instances, the collection reservoir may become full and it would be 
desirable to exchange the reservoir with another. The collection reservoir 
can be removed from the assembly by disconnecting at the connector 40. A 
second collection reservoir with its drip chamber and second length of 
tubing can be connected to the remaining part of the connector 40 on the 
first length of tubing, thereby again permitting fluid flow through the 
entire assembly into such a second collection reservoir. 
It is desirable to have a tamper-evident seal extending around the 
connector as the assembly herein described is essentially a closed system. 
Such a closed system is desirable as it prevents or inhibits the 
introduction of bacteria and other microbes to the patient. Once the 
system has been opened, more caution may need to be exercised to avoid 
introducing infection to the patient. Once the tamper-evident seal has 
been broken, the broken seal will alert the attendant to the fact that 
caution should be exercised to inhibit or prevent infection. 
The fluid flows through the connector, through the second length of tubing 
and into the collection reservoir. The collection reservoir can be 
provided with a drip chamber through which the fluid flows. By monitoring 
the drip rate through the drip chamber, the rate of the fluid flow can be 
determined. The fluid is collected in the reservoir and its volume can be 
measured by appropriate graduations on the reservoir. 
The collection reservoir can also be provided with a height scale along its 
side as indicated in the drawing. Such a height scale can provide for 
balancing the pressures. That is, balancing the level of liquid in the 
reservoir with the patient, to maintain the fluid pressure within the 
ventricles and avoid siphoning of the fluid. 
If a sample of the fluid from the collection reservoir is desired, such a 
sample can be obtained through the withdrawal site on the outlet port. A 
needle cannula of a syringe can be inserted through the withdrawal site 
and a sample of the fluid obtained. Upon withdrawal of the needle, the 
withdrawal site seals upon itself, preventing any further flow of fluid. 
If the collection reservoir becomes full and it is necessary to maintain 
the assembly attached to the patient for further drainage of CSF, then the 
fluid in the collection reservoir can be drained through the outlet port. 
This can be accomplished by cutting off the withdrawal site and allowing 
the fluid to drain. A clamp can then be inserted on the outlet port to 
prevent any further flow of fluid from the reservoir. The collection 
reservoir can also be drained by inserting a needle cannula of a syringe 
through the withdrawal site and withdrawing fluid until the bag is empty. 
This maintains a closed system. After draining the collected CSF, 
additional fluid can be collected in the same reservoir. This assembly 
also provides that should it be desirable to change collection reservoirs 
rather than drain the collection reservoir, the exchange can be 
accomplished readily by disconnecting the connector 40 between the first 
and second lengths of tubing. A second collection reservoir can then be 
reconnected to the connector 40. 
The external ventricular drainage assembly herein can be provided in a kit 
form. Such a kit can contain each of the elements of the assembly shown in 
the drawing. By providing the assembly in a kit, the entire assembly can 
be sterilized and packaged or packaged and sterilized prior to its use. 
The kit also provides that the assembly can be preassembled with each of 
the components already connected to the other components which constitute 
the assembly. The kit in such a preassembled form provides a quick and 
easy drainage assembly which can be connected to the patient and once 
connected, is ready for use.