For some, an alternative to inserting a shunt is another surgical procedure called Endoscopic Third Ventriculostomy (ETV). During this procedure, an endoscope (a device surgeons use to see inside the body) creates a small hole in the floor of the third ventricle in the brain. This creates an alternate path for CSF to flow out of the blocked ventricle and into the other cavities of the brain and then elsewhere in the body so there is no accumulation in the brain.