Patency Test (Post-Operative); Patency Test Downstream Of The Reservoir (Valve And Distal Catheter); Sampling The Csf And Injection; Potential Causes Of Adjustment Difficulties And Suggested Measures - Sophysa POLARIS SPV-SX Notice D'emploi

F 10 – C
IGURE ONFIRMATION OF THE OPERATING PRESSURE
(
RADIOLOGICAL VIEWS OF THE VALVE
®
On the Polaris valve, each of the five valve pressures is
located by the position of the radio-opaque identification
point for the corresponding operating pressure.
Locate the valve inlet connector, wider due to the
presence of a nut.
The position for the lowest operating pressure (Position No.
1) is the position located nearest to this connector.
If the right-hand valve rotor micro-magnet is facing the
radio-opaque point nearest the inlet connector, the valve is
set at the lowest pressure (Position No. 1).
Then, moving clockwise away from the inlet connector,
each of the following radio-opaque points corresponds to
a higher pressure.
The radio-opaque point furthest away from the valve inlet
connector corresponds to the highest pressure (Position
No. 5).

9.6. PATENCY TEST (POST-OPERATIVE)

There are two steps for the post-operative test on the
patency of the shunt :
9.6.1. Testing the patency of the ventricular
catheter
NOTE
This test is possible with SPVA (antechamber) and SPVB
(burr hole reservoir) type models. For the SPV type model,
a ventricular catheter with reservoir must be used.
Pinch the catheter with a finger just after the valve outlet
connector.
With another finger, press the reservoir to make the CSF
flow back into the ventricular catheter. A reservoir that
cannot be compressed easily or does not fill quickly may
indicate there is an obstruction in the ventricular catheter.
9.6.2. Patency test downstream of the reservoir
(valve and distal catheter)
NOTE
This control is impossible with a SPVB type model (burr
hole reservoir) because there is no access to the ventricular
catheter upstream of the reservoir.
SPV )
MODEL
Pinch the catheter with a finger just before the reservoir,
then with another finger press the reservoir to push the
CSF through the valve and distal catheter. A reservoir that
cannot be compressed easily may indicate an obstruction
either of the valve or the distal catheter.
PRECAUTION
Do not rely only on the characteristics of the patency test to
diagnose an obstruction in the shunt system. Obstruction
of a shunt system can occur in any of its components and
should be diagnosed first of all by the clinical data and
additional examinations.

9.7. SAMPLING THE CSF AND INJECTION

Access to the CSF is obtained by pricking the reservoir
with a 24G (or smaller diameter) Huber needle.
The integral reservoir on the SPVA and SPVB type models
is designed for occasional use.
Its watertight performance is reduced after very frequent
pricking into the dome.
— To inject in the proximal direction, compress the
catheter just after the valve outlet connector.
— To inject in the distal direction, compress the catheter
upstream of the reservoir.
NOTE
Elective injection in the distal direction is not possible with a
model of the SPVB type (burr hole reservoir) because there
is no access to the ventricular catheter upstream of the
reservoir.
Ensure that the base of the reservoir is not crossed with the
needle.
PRECAUTIONS
Do not inject into, or take samples from, the CSF without
having tested the shunt patency. Significant overpressure
could damage the shunt if it is known that there is an
obstruction.
Do not inject too fast or inject too great a volume. The
increase in pressure could damage the shunt.
Do not use a syringe with a volume of less than 10cc for
injections or taking samples. Too great a pressure could
damage the shunt.
9.8. POTENTIAL CAUSES OF ADJUSTMENT
DIFFICULTIES AND SUGGESTED MEASURES
Poor positioning of the Locator in relation to the center of
the valve or incorrect orientation of this Locator in relation
to the axis of the connectors may lead to an inaccurate
or incorrect reading of the operating pressure on the
Compass and/or difficulties in making adjustments with the
Magnet.
Before anything else, check that the Locator is correctly
positioned and oriented above the valve (cf. Steps 3b "
Positioning the Locator " and 5b " Orientation of the
Locator " in the §9.4 - Operating pressure setting after
implantation).
ENGLISH – 15