Hydrocephalus is usually the result of obstruction to cerebrospinal fluid flow. The aetiology may be congenital as in Arnold-Chiari malformation, or acquired as in brain tumours or intraventricular haemorrhage. The incidence of hydrocephalus is between 0.3-1.5 per 100 live births in the United States. Ventriculomegaly alone occurs in approximately 0.5-2 per 100 live births. Surgical correction involves draining fluid from the ventricular system to one of three places: peritoneum, atrium, or the pleural cavity. The most common choice is a ventriculoperitoneal shunt. As the child grows, the shunts often require replacement or revision making ventriculoperitoneal shunt placement or revision, one of the most common pediatric neurosurgical procedures.