Prior CSF shunting increases the risk of endoscopic third ventriculostomy failure in the treatment of obstructive hydrocephalus in adults

Introduction: Endoscopic third ventriculostomy (ETV) is accepted as an effective treatment for obstructive hydrocephalus (OHC); however, its benefit in patients previously treated with cerebrospinal fluid (CSF) shunting remains unclear. The value of concurrent ETV and ventriculoperitoneal (VP) shunting in patients with frequent shunt failure remains unstudied. Methods: Outcomes were compared between OHC patients receiving ETV as initial CSF diversion treatment (n = 19) versus OHC patients receiving ETV for shunt failure (n = 11) by log-rank analysis and Kaplan-Meier plots of recurrence-free periods. To determine if the performance of ETV with concurrent shunt revision decreased the incidence of catastrophic treatment failure in patients experiencing frequent and emergent shunt failures (n = 8), the time to treatment failure after ETV and shunt revision was compared with the mean duration of their previous CSF shunts. Results: ETV after shunt failure was 2.5-fold more likely to fail [risk ratio (RR): 2.48, p