Ventricular reservoir (Ommaya reservoir)

What it is

A ventricular reservoir (one common type is the Ommaya reservoir) is an implanted device, placed under the scalp and connected to a catheter in a ventricle, that provides repeated access to the ventricle. It allows CSF to be drained or sampled with a needle through the skin.

Understanding Ventricular reservoir (Ommaya reservoir)

In the context of hydrocephalus, a ventricular reservoir is often used as a temporizing measure in premature or small infants with post-hemorrhagic hydrocephalus: CSF can be removed (tapped) from the reservoir periodically to control pressure and ventricle size until the baby grows and a permanent solution (such as a shunt or ETV) becomes appropriate. The reservoir provides controlled, repeatable access without a fully externalized drain. (Reservoirs are also used in other contexts, such as delivering medication into the CSF for certain conditions.) The reservoir is one of the temporizing options for managing hydrocephalus in small infants.

Why it matters

Understanding the ventricular reservoir helps families see how CSF can be repeatedly removed to control hydrocephalus in a small infant — as a temporizing measure — until a permanent treatment is appropriate.