The purpose of the study is to compare the survival time (time to first shunt failure) of ventriculoperitoneal (VP) shunts inserted through an anterior entry site with those inserted through a posterior entry site in children. Shunt entry site is the location on the head that the shunt catheter enters the brain on its path to the fluid-filled spaces in the brain, the ventricles. Entry sites can be anterior or posterior.

The study is a multi-centered, randomized, controlled trial comparing two commonly used CSF shunt insertion techniques, anterior and posterior entry site. There is conflicting information and opinions in the pediatric hydrocephalus literature regarding entry site's effect on shunt survival. This trial is designed to detect a 10% or more difference in the rate of shunt survival at one year between the two techniques.

The trial will be conducted by the Hydrocephalus Clinical Research Network and the Hydrocephalus Association. It is a four year study with an estimated sample size of 448 patients. Patients will be randomized in the operating room. Subjects will be followed for a minimum of 18 months.

Inclusion Criteria:

1. Less than 18 years of age at the time of shunt insertion; AND
2. Clinical evidence of hydrocephalus that requires a simple ventriculoperitoneal shunt as determined by a pediatric neurosurgeon; AND
3. No prior history of shunt insertion (a history of an external ventricular drain, ventricular reservoir, subgaleal shunt, and or endoscopic third ventriculostomy with or without choroid plexus coagulation is permissible); AND
4. Ventriculomegaly on imaging.

Exclusion Criteria:

1. Need of a shunt that is not a simple ventriculoperitoneal shunt. For example: Patients who require more than one intracranial catheter are excluded. Patients who require a ventricular shunt that terminates in the atrium of the heart, the pleural cavity, the gallbladder, or any other terminal location that is not the peritoneal cavity are excluded. Patients who require a subdural to peritoneal or a cyst to peritoneal shunt are excluded.
2. Active CSF or abdominal infection;
3. CSF leak without hydrocephalus;
4. Pseudotumor cerebri;
5. Hydranencephaly;
6. Loculations within the ventricular system (e.g. large intraventricular cysts or ventricular adhesions which create compartments that distort the ventricular anatomy; isolated trapped lateral ventricle). A small cyst within the ventricle does not meet these criteria;
7. Other difficulties that would preclude follow up at one year (e.g. terminal illness with life expectancy less than 18 months; family plans to move out of region or country);
8. A bilateral scalp, bone, or ventricular lesion that makes placement of either an anterior or a posterior shunt impracticable (e.g. cutis aplasia);
9. Bilateral slit like frontal horns or trigones defined as the widest distance between the medial and lateral walls less than 3 millimeters.
10. Patient is scheduled to have an intra-ventricular procedure (e.g. ETV, endoscopic biopsy, arachnoid cyst fenestration, fenestration of septum pellucidum) in addition to possible or definite VP shunt.

Adjudication committee reviews blinded notes, data collection forms, and films to determine shunt failure.