Function Of The Valve; Selecting The Appropriate Shuntsystem; Possible Shunt Components - MIETHKE miniNAV Instrucciones De Manejo

| INSTRUCTIONS FOR USE
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FUNCTION OF THE VALVE

The operating principle of the miniNAV is illus-
trated in fig. 3.
Fig. 3a shows the miniNAV in the horizontal po-
sition. The ball-cone valve is closed and draina-
ge is prevented.
If the patient's IVP increases and continues to
rise, the spring pressure of the ball-cone unit
will be overcome. The sealing ball will move
away from the cone and a gap opens for fluid
drainage.
a)
b)
Fig. 3: miniNAV
a) closed and b) open
SELECTING THE APPROPRIATE
SHUNTSYSTEM
The miniNAV is available in four different pres-
sure pressure levels (0, 5, 10 and 15 cmH
The pressure setting should be chosen accor-
ding to the clinical picture (normal-pressure hy-
drocephalus, hypertonic hydrocephalus).
In case the patient suffers from symptoms asso-
ciated with overdrainage, or complications with
overdrainage are expected, we recommend
the implantation of the SHUNTASSISTANT
in addition to the miniNAV. The SHUNTASSI-
STANT is a hydrostatic, supplementary valve
specially designed for preventing problems with
overdrainage. It is made by Christoph Miethke
GmbH & Co. KG.
The coding of the miniNAV can be identified
according to the shape of the valve's housing.
For example the miniNAV with an opening pres-
sure of 5 cmH
O has a concave proximal part
2
(curved inwards) and a convex distal part (cur-
ved outwards). (Fig. 4)
Each miniNAV is calibrated in accordance with
strict quality control standards. The following
pressure levels are available:
14
pressure
rating
(cmH O)
2
0
5
10
15
Fig. 4: X-ray image of the miniNAV
(pressure rating 5 cmH
O).
2

POSSIBLE SHUNT COMPONENTS

The miniNAV is available with different shunt
accessories. These variations are comprised of
a variety of components, which are described
briefly introduced below:
The borehole reservoir is position ed in the cra-
nial borehole. It allows measurement of intra-
ventricular pressure, injection of drugs and ex-
traction of CSF. Its solid titanium base is highly
puncture-resistant. All reservoirs are available
with integrated catheters or connectors. A spe-
cial borehole reservoir is the SPRUNG RESER-
VOIR. An additional new feature of this reservoir
is that CSF can be flushed towards the miniNAV
because of a non-return valve in the bottom of
the reservoir. By this mechanism, flow in the di-
rection of the ventricular catheter is avoided du-
ring the pumping procedure. The opening pres-
sure of the shunt system is not increased by
the implantation of the SPRUNG RESERVOIR.
Coding
a
b
O)
2
miniNAV
concave
a
convex
b