The principal advantage of treating hydrocephalus primarily by third ventriculostomy whenever possible is the avoidance of a diversionary cerebrospinal fluid (CSF) shunt, thereby sparing the patient the dangers and distress of further surgery for shunt complications. Nearly 40 years ago, a study comparing 618 published cases of hydrocephalus treated by operations not requiring implanted materials with 1087 published cases treated by implanted shunts, identified that, whereas early success rates were equivalent at around 65%, the late complication rates were vastly different at 35%–100% for implants versus 3%–5% for non-prosthetic techniques [52]. The risk of shunt failure is so great that the patient with a shunt can effectively expect further surgery (see Chap. 22). The risk is cumulative over time, rising to 81% by 12 years [48] and 83% by 20 years [55]. This background combined with the renaissance of neuroendoscopic neurosurgery provides the rationale for neuroendoscopic third ventriculostomy (NTV) ab initio (primary NTV); it is an even more logical approach to the management of shunt malfunction, as an alternative to shunt revision.