| Discussion: |
The most common complication of a ventriculo-peritoneal shunt is mechanical malfunction of the shunt system. Malfunction may be the result of obstruction, disconnection/fracture of the component parts of a shunt system and infection.
Malfunction of a ventriculo-peritoneal shunt may be due to disconnection, with separation of the ventricular catheter from the rest of the shunt system. Obstruction of the shunt at the proximal end, resulting in malfunction is due to the blockage of ventricular catheter by choroid plexus and glial tissue growing into the lumen of the ventricular catheter. Proximal shunt failure resulting in malfunction is due to the catheter tip becoming embedded in the periventricular ependymal and neural tissue. Signs and symptoms of mechanical shunt malfunction are a result of fluid pressure building up within the head. These include headache,neck pain, malaise, vomiting, mental status changes, increased blood pressure, increased head circumference, bulging fontanelle and sixth nerve palsy signs. There can be an increased risk of seizures.
Infections of the shunt can occur causing it to malfunction. They could be external infections as a result of necrosis of the skin overlying the shunting device and internal infections primarily within the shunt system. The most common organisms involved are S.aureus and S.epidermidis. Shunt infection can cause fever, meningeal signs, vomiting, abdominal pain, purulent material around the shunt insertion site and redness along the shunt tract. In addition, shunt infection can cause signs and symptoms of mechanical shunt malfunction.
Median survival of a shunt (before need for revision) in a child under 2 years of age is 2 years; over 2 years of age is about 8-10 years.