Approximately 25-35% or more of children with myelomeningocele are born with hydrocephalus, and an additional 60-70% of patients with myelomeningocele develop hydrocephalus after closure of the back lesion. Hydrocephalus can cause expansion of the ventricles is associated with a considerable decline in intellectual function (Toporek, 1999).

In a few cases, the hydrocephalus arrests spontaneously, but, in most cases, shunting is required. Ventriculoperitoneal shunting is the preferred modality. Alternatives include ventriculoatrial and ventriculopleural shunting (Parker, 2002).

Postoperative complications include cerebral and/or ventricular hemorrhage, bowel perforation, and infection. Long-term complications include infection, over drainage or under drainage, and obstruction of the shunt system (Toporek, 1999).

Repeated prolonged shunt dysfunction can lead to additional functional and cognitive decline. Shunt obstruction may be accompanied by development of acute or chronic rise in intracranial pressure (excess fluid on the brain). Diagnosis may be difficult, as early signs and symptoms often are nonspecific. Shunt failure is more common in the first 2 years of life (Tomlinson, 1995).