JPS5841065B2 - ventricular drainage valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Treatment of cerebral edema always involves surgical implantation of a ventricular drainage device to drain excess cerebrospinal fluid (C8F) from the ventricles.

This ventricular drainage device generally comprises a cerebral catheter that is inserted through the brain tissue into the ventricle and connected to the jugular vein or other storage cavity of the body via a one-way valve device for drainage. .

The device is designed to remove excess C8F from the ventricles, i.e.
Provided to constrict the size of the ventricles.

Drainage control is usually provided by a one-way valve operating at a constant closing pressure.

Although cerebral edema is often associated with abnormally high C8F pressures, there are many cases in which cerebral edema is associated with normal C8F pressures.

Wabert J. Ojeman, Normal pressure cerebral edema, Clinical Neurosurgery, Vol. 18, pp. 337-370, 1971 (Ojem
ann.

RobertG, Normal Pressure
Hydrocephalus, C1inC11nica
lNeuro-sur,'Vo1.18. pp.

337-370.1971).

Analyzing the fluid dynamics involved in normal-pressure cerebral edema syndrome, the increase in effective force from the ventricles does not depend solely on C8F pressure, but is the product of C8F pressure and ventricular area.

In other words, when the ventricles are enlarged, ``normal pressure 11'' is acting.

Thus, in normal pressure cerebral edema, the ventricular area under C8F pressure is larger than normal, so the ventricles remain enlarged and therefore the total force on the brain tissue is equal to the pressure and area. The product becomes very large.

[Nis Hakim and R.D. Adams.

Special clinical problems related to symptomatic cerebral edema with normal cerebrospinal fluid pressure: Report on cerebrospinal fluid fluid dynamics, Annual Signs, Vol. 2, pp. 307-327, 1965 (S-Haki)
m and R-D-Adams,,The 5pe
cial problem of
symptomatichydrocephalus
with normal cerebrospina
l fluidpressure: obse
rvations once brospinal
fluidhydrodynamies-J, Ne
ural.

5ci-, Vol 2 pp, 307-327.1
965)].

In addition to the forces exerted by C8F, the brain tissue is subject to opposing forces expressed by the intraparenchymal system of the organ, ie, the venous blood pressure of the brain tissue itself.

C8F pressure tends to enlarge the ventricles, whereas venous pressure tends to decrease ventricular size.

These two forces are normally in equilibrium such that ventricular size neither increases nor decreases but remains constant throughout life.

Therefore, the purpose of treating cerebral edema with drainage treatment is not only to stop the progression of symptoms, but also to restore ventricular dimensions to as normal as possible.

Once cerebral edema has occurred, recovery is achieved by eliminating the imbalance between the two forces acting on the brain parenchyma.

The C8F pressure is reduced by an amount proportional to the size of the ventricles, thereby offsetting the increased force caused by the enlarged ventricles.

The forces developed within the venous system are then able to cause the compressed brain tissue to bounce back elastically against the low C8F forces, and the venous bed recovers lost volume and becomes free-flowing.

In this way, brain metabolism normalizes and brain tissue recovers.

In cerebral edema treatment, reduction of C8F pressure is accomplished by an anastomotic device containing a one-way valve with an operating pressure equal to the desired C8F pressure.

With this anastomotic device, the C8F pressure is maintained at a maximum level determined by the subcutaneously inserted valve, and drainage of C8F fluid from the ventricles continues as long as the C8F pressure is greater than the valve's operating pressure.

To cure normal pressure cerebral edema, a working pressure lower than normal, e.g. 36
~407+! Because subcutaneous insertion of a valve with a working pressure of 11H20 (mm water column) is required, C8F pressure is maintained below normal as ventricular size decreases.

On the other hand, venous blood pressure remains normal. As a result, power imbalances are eliminated.

The venous system force becomes larger than the C8F system force because the ventricular area gradually becomes smaller and the C8F pressure decreases.

Therefore, once the ventricles have normal dimensions again, intraventricular C8F pressure must be restored to normal levels.

If this happens, there will not be enough force in the ventricles and the brain will not expand normally.

Also, if the C8F pressure remains below normal, unfavorable pathological consequences such as venous "swelling11" or hyperemia, cerebral edema, "fissure ventricles11" and cranial anomalies can result from overtreatment of cerebral edema. There is sex.

On the other hand, it is known that complications such as dural smooth sac hydrocele, hematoma, and skull polymerization occur.

The ability to control C8F pressure relative to the ventricular region is important for proper treatment of cerebral edema, since proper balance within the brain must eventually be achieved.

Briefly, the problem in correcting and maintaining correct normal hydrodynamic equilibrium in the cranial cavity is to maintain intraventricular C8F at a certain pressure corresponding to the ventricular region.

Once the ventricle reaches normal size, the valve provided for initial drainage should be anchored with a closing force equal to normal C8F pressure (125-150) and H20.

To date, the problem of maintaining a precise balance of C8F pressure, ventricular area, and venous blood pressure within the brain has not been understood.

In an ideal drainage system, the valve should be provided for initial drainage at a pressure below normal and then operated at an operating pressure that maintains correct intercranial balance.

Accordingly, in one aspect, the present invention provides a ventricular drainage valve having means for regulating and varying the valve operating pressure to the ventricular region such that proper intracranial force balance can be maintained.

On the other hand, the invention takes advantage of the fact that brain tissue is itself a viscoelastic tissue that transmits forces that develop outwardly against the dura mater in the ventricles.

This force is sensed and utilized to control the operating pressure of the ventricular drainage valve to properly maintain proper drainage conditions and force balance.

The invention features an actuation pressure that is variable to the ventricular region so that the force exerted on the brain by the ventricular C3F pressure can be appropriately balanced with the constraining force exerted by the venous blood pressure. Provides a valve for ventricular drainage.

This valve is therefore inserted subcutaneously and regulates the drainage of C8F from the ventricle at an appropriately low valve operating pressure (e.g. 45 mmH20) when the force of C8F becomes excessive and the brain tissue relaxes and the ventricular area decreases. The time is provided to increase the operating pressure.

Applicants have discovered that the forces acting on the brain resulting from C8F pressure applied to the ventricular region are transmitted through brain tissue, such as viscoelastic tissue, and are sensed in the subdural region, where the brain is in close proximity to the cranium. I found out that it can be done.

The invention features a sensor inserted into the dural area between the brain and the skull, which cooperates with a ventricular valve whose actuation pressure varies inversely to the force applied to it. work

In an embodiment of the invention, the inverse variation of the valve operating pressure is preferably done by a fluid pressure feedback device.

That is, a force applied to the sensor reverses the spring bias that controls the actuation pressure, so that an increase in force is transmitted to reduce the actuation pressure.

The spring biased to close the valve is unloaded in response to the force applied to the sensor by the brain.

FIG. 1 shows a mode of surgery for implanting a ventricular drainage device.

Ventricular catheter 50 is inserted through hole 52 in skull 54 and into ventricle 56 through brain tissue 58 and is connected to drainage catheter 62 via drainage valve 60 .

Catheter 62 would normally be introduced into the right atrium, peritoneal cavity, or other suitable storage cavity.

An improved drain valve according to the present invention is included in valve 60.

The force applied to the brain is caused by fluid filling pre-2, which is hydrodynamically connected by tube 25 to the device of valve 60, described below.
Sensed by 4.

The sensor is also inserted through the dura mater 64 through the perforation and preferably against the arachnoid membrane 66 over one or more girths or 118.

To best respond to brain power, a close connection between brain tissue (cortex) and sensors is required.

The spider subretinal space surrounding the gyrus is itself dependent on cerebrospinal fluid pressure (C8F pressure) and tends to give a pressure response to the sensor output rather than force.

It will be appreciated that the purpose of this is to sense the force exerted by the brain tissue that is distinct from the C8F pressure.

Typically, in ventricular drainage devices, the entire drainage assembly is ultimately properly covered and retained by an overlying scalp (not shown).

A hydraulic servo drain valve according to the present invention, as embodied in FIG.
2, and features a housing 10 and a valve body 12 formed therein, the valve body 12 being formed with a conical valve seat 15 forming an outlet from an inlet groove 14.

A spherical valve member 16 is held down by a spring 18, which rests within the conical valve seat and holds the valve closed until fluid pressure at the inlet is strong enough to overcome the biasing force of the spring. do.

Spring 18 is attached to substrate 20.

This base plate 20 is then pivoted to the valve body 12 at the end of the spring remote from the valve body.

A preload spring 21 extends from the forward shoulder 19 of the valve body and positions the base plate 20 so that the valve spring deflection is immediately maximum vertically.

The substrate 20 lies spaced apart in a recess in the valve body in which is fitted a valve groove 22 that is hydrodynamically connected to a sensor 24 by a tube 25 .

The valve groove 22 is configured to be hydrodynamically loaded or expanded, pushing the substrate 20 against the force of the preload spring 21;
This moves the valve spring away from the valve ball 16 and removes the load on the valve spring.

The valve spring 18 is thus relieved of tension and the force applied to the sphere is reduced.

Correspondingly, the operating pressure of the valve, which is the fluid pressure at the inlet required to open the valve, is reduced.

With subcutaneous insertion, outward forces exerted by the brain are applied to a sensor 24 located in the subdural region between the brain and the skull, which is then hydrodynamically transmitted to the valve groove 22.

Therefore, as the force exerted by the C8F pressure applied to the ventricular area increases, the operating pressure of the valve decreases.

The reverse also holds true. Therefore, the hydraulic side
Contraction due to brainIJscsF drainage results in decreased brain power and increased operating pressure to effectively maintain proper drainage and balance of the various forces.

Both the sensor 24 and the valve groove 22 are conveniently constructed of a plurality of silicone rubber disks whose edges are bonded together with a silicone bonding agent of the RTV type or polymerizable by ionizing radiation.

A silicone tube 25 attached to the disc is provided between the capsules to provide a fluid connection.

The sac and canal are made of ethyl iodophenyllandesylate (eth
(yliodophenyl undecylate)
Filled with radiopaque oil such as.

Such an oil would moisten the valve system to a suitable viscosity, allow the hydraulic servo coupling to be viewed radiologically, and would also provide a safe material for frequent use in spider subretinal space radiography. It is.

The valve arrangement shown in FIG. 2 is the downstream end of a pair of check valves described in U.S. Pat. It will be understood that it can be attached to

The actual construction is generally conventional, and stainless steel is chosen for the housing 10, valve body 12, spring 18, base plate 20 and preload spring 21.

Spherical valve member 16 is preferably made of synthetic sapphire.

Biasing spring 18 is point welded to substrate 20. Preload spring 2
1 is point welded to the transverse layer 19.

The pivoting of the base plate 20 to the downstream end of the valve body consists of a pin member 23 point-welded to the underside of the base plate 20, which pin 23 is formed in the hypodermic needle tube and is attached to the downstream end of the valve body 12. It is configured to be received within a sleeve 26 which is spot welded to the upper side.

The tube 25 passes through an opening 27 in the valve body 12 and also through the tube 11, which is sealed with silicone cement.

The subcutaneous insertion of the valve of the present invention in the lateral ventricular anterior chamber drainage system is done according to standard surgical procedures, with the additional step of inserting the sensor 24 into the subdural area.

Most conveniently, the sensor 24 is introduced through a perforation and then lies between the brain and the skull at a small lateral distance.

After subcutaneous insertion of the device, it is desirable to make hydraulic adjustments to the servo linkage to ensure that the valve opens and closes appropriately in response to changes in sensor force.

This is accomplished by sandwiching the sensor between silicone flakes or by injecting and removing fluid with a hypodermic needle, preferably through a branch tube (not shown) which is then sealed.

In the embodiment illustrated in FIG. 3, the valve emerges from an elastic hollow closed tube 70 in which a longitudinal slit 72 is formed.

C8F fluid flows into valve line 70 and under sufficient pressure slit 72 is opened for drainage.

The slit is also under the control of the internal spherical front 22a.

This spherical front is hydrodynamically connected to the sensor 24 and is expandable under fluid pressure and serves to open the slit.

In the embodiment illustrated in FIGS. 4 and 5, the construction is generally as described in connection with FIG. 2, except that the control mechanism is mounted on the underside of the substrate 20. It is different in that it consists of a pin 76 with a cylindrical shape and passes through a silicone rubber seal T8.

The pin 76 is adjustably connected or threaded to a sensor 80 placed in contact with the exterior of the brain in the dural area.

The threaded engagement of pin 76 and sensor 80 is provided for adjustment to the individual patient.

The installation for this embodiment is illustrated in FIG. 5 and is characterized by two perforations 85 and 86, the former for accommodating the catheter 50 and the latter for accommodating the sensing device.

The valve device has a screw 92 that passes through the valve body 12 and the valve is attached to the skull.
Mounting pin 9 terminating in a retaining hole adapted to be tightened with
0 is conveniently attached to the skull.

In the embodiment illustrated in FIGS. 6, 7 and 8, the valve device is contained within an elastic chamber 102 or silicone rubber formed to be placed directly in contact with the brain in the dural area. It will be done.

Catheter 50 is guided into chamber 102 and terminates in an elastic closure tube 100 having a transverse slit 108 in the side wall.

The top and bottom portions of the tube 100 contact the opposing top and bottom walls of the chamber 102 and may be integral with the small metal disk 106 .

Drainage catheter 104 exits chamber 102.

In operation, sufficient C8F pressure causes slit 108 to open, allowing drainage of catheter 50 to chamber 102.

If excessive forces occur, the chamber 102 will be compressed and the disc 1
06 presses the tube 100 to open the slit 108.

Drainage at low C8F pressures is done in this way.

As the brain contracts, less force is applied by the disc 106, and for drainage, the increased C8
F pressure is required.

In this way proper drainage conditions and balance of the various forces can be maintained.

As can be seen from the above description, this invention has been described in terms of preferred embodiments, and although those skilled in the art will be able to conceive of various modifications based on the principles of this invention, this invention remains within the spirit of this invention. should be broadly protected based on the

[Brief explanation of the drawing]

1 is a diagrammatic explanatory diagram showing a valve device in a physiological environment; FIG. 2 is a longitudinal sectional view of a valve device and a sensor according to the invention; and FIG. FIG. 4 is a longitudinal cross-sectional view showing an embodiment featuring a non-device feature; FIG. 4 is a longitudinal cross-sectional view showing a valve device featuring a mechanical brain force sensing control element; FIG. FIG. 6 is a plan view showing subcutaneous insertion of the valve device shown in FIG. 6; FIG. , a plan view of the embodiment shown in FIG. 6, and FIG. 8 a cross-sectional view taken at 8--8 of FIG. 10...Housing, 11...Hollow tube, 12...Valve body, 14...Inlet groove, 1
5... Valve seat, 16... Valve member, 18...
...Spring, 19...Shoulder, 20...
・Board, 21...Preload spring, 22...
・Valve groove, 22a... Sacculus, 23...
Pin, 24...sensor, 25...tube,
26...Sleeve, 27...Opening, 5
0... Ventricular catheter, 52... Perforation, 54... Cranium, 56... Ventricle, 58
...Brain tissue, 60...Drainage valve, 62...Drainage catheter, 66...
... Arachnoid membrane, 68 ... Waist circumference, 70 ...
...Elastic hollow closing valve pipe, 72...Slit, 7
6...Pin, 78...Seal, 80.
...sensor, 85.86 ...perforation, 90
...Mounting pin, 92...Screw, 100
...... tube, 102 ... elastic chamber, 104.
...Drainage catheter, 106...
Disc, 108...slit.

Claims (1)

[Scope of Claims] 1. A conduit member having an opening and an outlet, a valve body disposed in the conduit and having a passage between the inlet and the outlet and leading to a valve seat, and a valve body provided in the conduit and having a passage leading to a valve seat, and a valve member mounted to form a closure of the passageway; resilient means movably attached to the valve member and biasing the valve member towards the valve member; force-responsive means coupled to said force-responsive means and adapted to increase the biasing force of said elastic means when the force decreases or increases; and movable means associated with said elastic means for reducing the amount of fluid in the ventricle. 2. A conduit member having an opening and an outlet, a valve provided in the conduit, elastic means for biasing the valve to a closed state, and a hydraulic servo mechanism, the hydraulic servo mechanism a sensing bladder adapted to contact the dural region and a control bladder disposed within the valve and associated with the elastic means to counteract the biasing force of the elastic means;
A ventricular drainage valve, wherein the sensing capsule and the control capsule are fluidly connected.