A<unk>  is a technique to channelise the cerebrospinal fluid (CSF) from the<unk>  thecal sac into the<unk>  cavity.
Lumbar–peritoneal shunt
Cerebrospinal fluid diversion
Cerebral shunt
Ventriculostomy
Ventriculotomy 
External ventricular drain
Craniotomy
Endoscopic third ventriculostomy