简介：AbstractBackground:Endoscopic third ventriculostomy (ETV) has been established as a viable treatment option for obstructive hydrocephalus of children over 6 weeks of age. ETV in pediatric groups may be unsuccessful due to the failure of absorption of cerebrospinal fluid (CSF) or reclosure of ventriculostomy stoma or due to infection. The exact cause is still debatable. Some issues like failure to eliminate the second membrane during the procedure or formation of the new arachnoid membrane at the stoma are still not clear. This study aims to assess the surgical failure of ETV and its predisposing factors.Methods:Thirty-four pediatric patients with hydrocephalus were analyzed retrospectively. The patients’ age limit was between 2.5 months and 14 years. This is a retrospective study of 34 patients in a single private hospital between June 2012 and January 2018. Patients having hydrocephalus in pediatric groups more than 6 weeks of age were included in the study.Results:The mean age of all patients was 51.25 ± 53.90 months and the mean follow-up period was 50.47 ± 20.84 months. Of 34 surgeries, the success rate was 79% and the failure rate was 21%. Within 2 years, the success rate was 68.42% and above 2 years’ success rate was 93.33%. In this series, 7 cases of ETV were re-explored and found ventriculostomy stoma closure in 3 cases, the presence of the second membrane in re-exploration 2 cases, and presence of inflammatory arachnoid membrane in re-exploration 2 cases. The use of dexamethasone around the stoma in inflammatory stoma was useful, having no recurrence. In one patient of the second membrane probably due to absorption failure in communicating hydrocephalus re-exploration was failed and was managed successfully with VP shunt.Conclusions:Predisposing factors causing ETV failure are ventriculostomy stoma closure by new arachnoid granulation tissues, remnants of the second membrane inside the stoma, CSF absorption failure, infection/high protein in CSF and inappropriate patient selection.