Hydrocephalus is the condition of having an abnormal accumulation of ceberbrospinal fluid (CSF) in the cavities of the brain. The condition may cause excess pressure inside the skull, which can result in the gradual enlargement of the head (in small children), headaches, decreased consciousness, and in extreme cases, death.

CSF shunts are the most effective way to remove the excess CSF and therefore, pressure. The fluid is drained from the ventricles, or cavities, into another absorption site (such as the right atrium of the heart or the peritoneal cavity) through a series of catheters. A valve, which functions as a regulatory device for the fluid, may be used along the catheter pathway.