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INSTRUCTIONS FOR USE
GB
The
prechamber
is positioned on the craniu m.
It allows measurement of intraventricular pres-
sure, injection of drugs, extraction of CSF and
palpatory ventricle inspection. Its solid titanium
base is highly puncture-resistant. A puncture of
the
prechamber
or the
CONTROL RESERVOIR
should be performed as perpendicular to the
reservoir surface as possible with a cannula
of maximum diameter 0,9mm. 30 punctures
are possible without any restrictions. A special
prechamber is the
CONTROL RESERVOIR
. As
an additional new feature of this reservoir, CSF
can be flushed towards the
miniNAV
because
of a non-return valve in the proximal inlet of the
reservoir. By this mechanism, flow in the direc-
tion of the ventricular catheter is avoided during
the pumping procedure. The opening pressure
of the shunt system is not increased by the im-
plantation of the
CONTROL RESERVOIR
.
Warning note: Frequent pumping can lead
to overdrainage and thus to pressure con-
ditions outside the normal physiological
range. The patient should discuss the risks
(involved) with their surgeon.
Tight tolerancing of the deflector ensures a
good fit with the ventricular catherther. By ad-
justing the deflector (prior to implantation) the
length of catheter penetrating into the skull can
be optimised. The ventricular catheter is “de-
flected” at a right angle in the borehole (see
chapter “Variations”).
TUBE SYSTEMS
The
miniNAV
has been designed to ensure the
optimal ventricular pressure. It is available as a
shunt system or as individual valve units with
or without an integrated distal catheter (internal
diameter 1.2 mm, external diameter 2.5 mm).
Individual valve units should be used with ca-
theters of approx. 1.2 mm internal diameter and
approx. 2.5 mm external diameter. The connec-
tor on the valve allows using catheters of 1.0
mm to 1.5 mm internal diameter. The external
diameter of the catheter should be about dou-
ble the internal diameter. Regardless, the ca-
theters must be carefully fixed, with a ligature,
to the valve connectors. It is essential that kinks
in the catheter are avoided.
The included catheters have virtually no effect
on the Pressure-flow characteristics.
SURGICAL PROCEDURE
Positioning the ventricular catheter
Several surgical techniques are available for po-
sitioning the ventricular catheter. The necessary
skin incision should be carried out, preferably,
in the shape of a lobule pedicled towards the
draining catheter or as a straight skin incision.
To avoid CSF leakage, care should be taken
that the dura opening is kept as small as possi-
ble after applying the borehole. The ventricular
catheter is stiffened by the introducing stylet
supplied with the product.
The
miniNAV
is available in different shunt va-
riations:
When using a
miniNAV SHUNTSYSTEM
with
borehole reservoir or
SPRUNG RESERVOIR
,
the ventricular catheter is implanted first. Once
the introducing stylet has been removed, the
patency of the ventricular catheter can be te-
sted by checking if CSF is dripping out. The ca-
theter is shortened and the borehole reservoir is
connected, with the connection secured with a
ligature. The skin incision should not be located
directly above the reservoir.
The
miniNAV SHUNTSYSTEM
with precham-
ber or
CONTROL RESERVOIR
comes with a
deflector. This deflector is used for adjusting the
position of deflection before implantation of the
ventricular catheter. The catheter is deflected;
the prechamber is put into place. The position
of the ventricular catheter should be inspected
again by postoperative CT or MR imaging.
Positioning the
miniNAV
The
miniNAV
should be implanted in the head
of the patient.
The valve is marked with an arrow pointing to
distal (downwards) to indicate the flow direc-
tion. Whether the label faces towards the skin
or the brain is of no importance in terms of the
valve‘s performance.
Following subcutaneous tunneling, the catheter
is either pushed from the borehole, possibly
through a reservoir, to the selected valve im-
plantation site; or it is pushed through from the
valve and connected to the reservoir, if there is
any.
Positioning the peritoneal catheter
The access site for the peritoneal catheter is left
to the surgeon’s discretion. It can be applied
e. g. para-umbilically in a horizontal direction or
