Stage III - Pressure Relief Mode
Should the intraventricular pressure (IVP) elevate abruptly, the shunt operates in a rapid flow rate mode to facilitate IVP
normalization. The valve then reverts to Stage II or I, depending upon conditions.
Implanted Materials
The implanted product may contain one or more of the following: Silicone elastomer with or without barium sulfate,
polysulfone, synthetic ruby, silicone adhesive, tantalum, polypropylene and epoxy.
Compatibility with other Medical Procedures
The OSV II Systems contain no magnetic parts, and are compatible with diagnostic procedures such as Magnetic
Resonance Imaging (MRI) and CT scans.
INDICATIONS
The OSV II System is an implantable system used in the treatment of patients with hydrocephalus, to shunt CSF from the
ventricles to the peritoneal cavity or other appropriate drainage site such as the heart's right atrium.
CONTRAINDICATIONS
This valve system should not be implanted when an infection along the shunt pathway (e.g. meningitis, ventriculitis,
peritonitis, septicemia, bacteremia) is suspected. It is advisable to postpone valve implantation if an infection is present
anywhere in the body. Atrial shunting is not advised for patients with congenital heart disease or other serious
cardiopulmonary abnormalities.
The OSV II should not be implanted in patients with untreated choroid plexus tumors. Such tumors produce CSF at rates
in excess of the specification of the flow regulation Stage II, and the OSV II would underdrain under these conditions.
The OSV II should not be used for drainage of extraventricular fluid collections such as hygromas or cysts; such
conditions are typically treated with very low differential pressure valves.
SIDE EFFECTS
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In addition to the risks associated with shunt system or component implantation, major complications include
mechanical failure, such as tubing fracture, material deterioration with time, or shunt pathway obstruction, infection,
reaction to materials, and CSF leakage along the shunt pathway. System disconnection can lead to catheter migration
into the atrium, peritoneum or lateral ventricles.
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Ventricular shunting has been associated with epilepsy, and shunt dependency. Intracranial hypertension
syndrome is a specific result of obstruction. Overdrainage may result in subdural hematomas, craniostenosis,
intracranial hypotension syndrome or sunken fontanelles (in infants).
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Shunt system failure should be suspected if any of these is noted: Continuing symptoms of hydrocephalus; CSF
leakage; redness, tenderness or erosion of the skin along the shunt pathway. These complications require prompt
replacement of the shunt system or affected component(s).
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Low-grade bacterial colonization may cause recurrent fevers, anemias, splenomegaly, shunt nephritis or
pulmonary hypertension.
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With atrial catheterization, the possibility of clot formation around the atrial catheter tip could lead to
pulmonary tree embolization.
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Perforation of an abdominal viscus is a rare complication of ventriculoperitoneal shunts.
PRECAUTIONS
•
Closely observe patients with an implanted valve system for shunt failure symptoms (see "Side Effects").
•
During implantation, have duplicates of each component available.
•
Handle valve tubing carefully. Cover forceps and clamp jaws with silicone elastomer tubing.
•
Do not lubricate valves. They will be lubricated adequately by CSF.
•
Silicone elastomer requires special handling to prevent contamination. Avoid contact with glove talc or skin oils.
•
The drainage catheter may be trimmed to the desired length during implantation. Other modifications are not
recommended.
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