Codman UNI-SHUNT, Manual

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Advance tip and guide shaft 3–4 cm through
opening. Unsnap leader clasp from handle. Pull
handle off guide shaft. Nestle distal tip of catheter
in leader clasp as shown in Figure 7.
Gently pull leader tip to draw leader through
guide shaft until the distal end of the catheter is
entirely drawn through. The guide now rests in the
subcutaneous space and the catheter is within it.
Remove leader clasp from catheter. Place gentle
pressure on catheter at head incision and gently
withdraw guide shaft distally. The catheter now
rests within the subcutaneous space.
Reassemble shunt passer. Tunneling is now effected
from abdominal incision
up to the interposing
incision. This is performed in the same manner as
the passage from the head incision. When tunneling
is complete, withdraw 3–4 cm of leader tip and
guide shaft.
Reverse leader within guide shaft so the distal end
of the catheter may be passed into guide shaft
at the interposing incision and withdrawn distally
through the abdominal incision.
Place gentle pressure on the catheter and
gently withdraw guide shaft distally through
abdominal incision.
Positioning Ventricular End of Catheter
The periosteum, skull and dura are opened by
means of any technique which is consistent
with the surgeon’s experiences in hydrocephalic
shunting and placement of ventricular catheters.
The ventricular end of the catheter is now
ready for insertion through the dural opening
and compressed cerebral mantle into the
dilated ventricle.
1. Insert the stylet tip into the designated hole
at the ventricular end of the catheter. A tantalum
marker lies adjacent to the ventricular hole through
which the stylet tip is inserted.
2. Apply slight pressure against the catheter and
both sliding clip and locking mechanism to align
the ventricular end to the introducer. (See Figure 9.)
The sliding clip and locking mechanism allow for
a variety of adjustments in catheter fixation
as dictated by the amount of catheter to be
inserted into the ventricle. The stylet tip conforms
to the contour of the catheter for ease of insertion
into the brain.
3. The introducer and ventricular end of the
shunt are then inserted through the dural
opening and compressed cerebral mantle
into the dilated ventricle.
4. The stylet is carefully withdrawn from the
introducer cannula. This will allow the proximal tip
of the ventricular catheter to disengage from the
stylet. Cerebrospinal fluid should drain from the
introducer cannula, verifying appropriate placement
of the catheter in the ventricle.
5. Disengage catheter from sliding clip and
locking mechanism.
6. Introducer is withdrawn while assistant holds
catheter in Cushing forceps with shod tips to
prevent damage to the shunt.
The one centimeter radiopaque markings on the
sides of the ventricular end of the catheter assist
the surgeon in determining radiographically exactly
how far into the ventricular system the shunt
tubing has been inserted. Once there is a free
flow of cerebrospinal fluid to the distal end of the
UNI-SHUNT with Reservoir, the catheter may be
precisely positioned in the brain by adjusting the
Reservoir’s position on the skull.
Placement of Anchoring Clip at
Ventricular End
The ventricular catheter is gently stretched and
eased into the plastic anchoring clip, as shown
in Figure 10. With the catheter in position, sutures
may be placed over the clip to further secure
placement.
WARNING: Do not use wire to suture
over the catheter; wire can cause damage to
the silicone catheter.
Use of the anchoring clip on the cranium is strongly
recommended to maintain the position of the
catheter in the ventricle of the brain.
Alternate Method for Positioning
Ventricular End with Anchoring Clip
The anchoring clip can be placed on the ventricular
end of the catheter prior to placement of the
catheter in the ventricle.
1. Position the catheter on the introducer and
align it by securing the catheter to the sliding
clip, as indicated in Positioning Ventricular End
of Catheter Steps 1 and 2.
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