Contraindications; Side Effects - Integra OSV II Mode D'emploi

DESCRIPTION
The OSV II® Hydrocephalus Valve System is an implantable device for controlled cerebrospinal fluid (CSF) drainage from the
ventricles to the peritoneal cavity or other appropriate drainage site such as the heart's right atrium. Unlike conventional valves,
the OSV II Valve System is a variable resistance valve which maintains a drainage rate close to the CSF secretion rate (20 ml/
hr) within the physiological range of intracranial pressure (ICP). The mechanism incorporates a safety pressure relief mode to
prevent accidental intracranial hypertension.
Caution: The Integra® OSV II® Valve may appear similar to the Integra® Flow Regulating Valve Low Flow, however, the Integra
Flow Regulating Valve Low Flow features a black radiopaque flow direction arrow to differentiate both products, visually during
implantation, and by X-ray, after implantation (See OSV II Valve X-ray image in Figure 8).
WARNING:
The Integra OSV II Valve System should be used in patients who need a drainage rate close to the CSF secretion rate (18-30 ml/hr).
For patients who need a lower drainage rate (8-17 ml/hr), the Integra Flow Regulating Valve Low Flow should be used.
Principles of Operation
The variable flow restrictor (Figure 1) consists of a silicone elastomer diaphragm (4), synthetic ruby seat (5), and notched pin (6).
The diaphragm reacts to differential pressure (DP) variations. The seat is inserted into the center of the diaphragm. As differential
pressure varies, the clearance between the seat and the pin increases or decreases depending on seat movement along the pin.
Changes in the seat and pin clearance vary flow rates. A typical flow/pressure curve is shown in Figure 2.
Note - Differential pressure/flow characteristics for each valve are verified to be within specification at time of manufacture.
The three stages of operation of the OSV II Valve System are defined below:
Stage I Low Differential Pressure
This stage begins when the flow rate through the valve reaches 5ml/hr (DP will be between 30 and 80 mm H₂0). The valve
remains in Stage I with CSF flow rates up to 18 ml/hr (DP will be between 40 and 120 mm H₂0).
Stage II Flow Regulation
When the DP increases, the valve operates as a variable resistance flow regulator. At DP ranges between 120 and 300 mm H₂0,
the valve restricts flow between 18 and 30 ml/hr.
Stage III Pressure Relief Mode
Should the intraventricular pressure (IVP) elevate abruptly, the shunt operates in a rapid flow rate mode to facilitate IVP norma-
lization. The valve then reverts to Stage II or I, depending upon conditions.
Configurations
The system is available in different configurations (see product label). A system generally consists of a ventricular (proximal)
catheter, a valve unit, and a drainage (distal) catheter. Depending on the configuration, the ventricular catheter is fully radio-
paque with radiopaque length markings at 2cm intervals from the tip or with a barium stripe and non radiopaque lengthmarkers
every 1cm. Some configurations contain an antechamber (standard or low profile, see Figures 6, 7, 8) or a burr hole cap. A mal-
leable tunneler is supplied with some configurations for subcutaneous tunneling of the distal tubing. Connectors are designed
for use with 1.1 to 1.4 mm inner diameter silicone elastomer tubings.
Implanted Materials
The implanted product may contain one or more of the following: Silicone elastomer with or without barium sulfate, silicone ink,
polysulfone, synthetic ruby, silicone adhesive, tantalum, polypropylene and epoxy.
INDICATIONS
The OSV II Valve 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 ) is
suspected. It is advisable to postpone valve implantation if an infection is present anywhere in the body (septicemia, bacteremia).
Atrial shunting is not advised for patients with congenital heart disease or other serious cardiopulmonary abnormalities.
The OSV II Valve System 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 Valve System would underdrain under these
conditions.
The OSV II Valve System 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

• 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, immune system
reaction to materials and CSF leakage along the shunt pathway. System disconnection can lead to catheter migration into
the atrium, peritoneum or lateral ventricles.
• 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).
• 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).
• Low grade bacterial colonization may cause recurrent fevers, anemias, splenomegaly, shunt nephritis or pulmonary hypertension.
• With atrial catheterization, the possibility of clot formation around the atrial catheter tip could lead to pulmonary tree
embolization.
• Perforation of an abdominal viscus is a rare complication of ventriculoperitoneal shunts.
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