MyPACS.net: Radiology Teaching Files > Case 409488

never visited VENTRICULO-PERITONEAL SHUNT MALFUNCTION
Contributed by: Shreeram Kumar, Resident, Advocate Lutheran General Hospital, Illinois, USA.
Patient: 6 year old male
History: Patient is a 6-year old boy with history of large frontal interhemispheric cyst, who underwent a cyst-peritoneal shunt placement as an infant. Routine examination in Jan 2004, showed VP shunt to be not palpable from neck to mid-thoracic region.
Images:[small]larger

Fig. 1: Lateral skull exam shows fractured shunt just below the occiput.

Fig. 2: AP CXR shows distal point of shunt fracture.
Findings: Lateral skull X-ray showed a shunt catheter tip anteriorly . At about the base of the occiput, the shunt was fractured. Distal point of fracture shown on AP CXR.
Diagnosis: Shunt fracture(as described above).
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.

References:

1) McLaurin, Schiut, Venes, Epstein. Pediatric Neurosurgery: Surgery of the developing nervous system, 2nd edition, 1989.
2) Roimondi AJ. Pediatric Neurosurgery: Theoretical Principles & Art of Surgical techniques.

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Additional Details:

Case Number: 409488Last Updated: 04-05-2004
Anatomy: Cranium and Contents   Pathology: Benign Mass, Cyst
Modality: Conventional RadiographExam Date: Access Level: Readable by all users
Keywords: shunt

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