Cerebrospinal fluid (CSF) diversion is a procedure that is used to drain fluid from the brain and spinal cord.

During the CSF diversion procedure, the neurosurgeon will place a shunt (a long, thin tube) in a ventricle of the brain and thread it under the skin to another part of the body, usually the abdomen. The shunt carries excess fluid away from the brain so it may be absorbed elsewhere in the body, and a valve controls the flow of the fluid.

It is used to treat hydrocephalus and idiopathic intracranial hypertension, among other conditions.