Background: Endoscopic third ventriculostomy (ETV) has been shown to be a sufficient alternative to shunts in surgical treatment of obstructive hydrocephalus. Long-term failure, age limitations, and outcome by cause are some of the issues debated in literature. The objective of this article is to analyze the clinical success and failure of ETV and its main complications. Methods: A total of 209 patients with hydrocephalus were submitted to ETV, including a mixed population of children and adults (from 0 to 59 years). Patients were divided into five groups: A – tumors, B – aqueductal stenosis, C – myelomeningocele, D – infection and hemorrhage, and E – arachnoid cyst. Variables were analyzed: age, ETV success rate, cerebrospinal fluid (CSF) fistula, mortality, and complications. Results: The two main causes of hydrocephalus were tumors (44.9%) and aqueductal stenosis (25.3%). The overall success rate was of 82.8%, and patients in Group E had the highest rate 90.9%. Group A had a success rate of 89.3%, and Group B had a rate of 88.6%. The ETV success rate was significantly higher in patients older than 1 year (P < 0.001); the former also had a lower risk of CSF fistula (P < 0.0001). The overall mortality rate was 2.8%. Conclusion: Better results were observed in the groups of patients with tumors, aqueductal stenosis, and arachnoid cysts, while those whose primary causes of hydrocephalus were myelomeningocele, infections, or bleeding had higher rates of failure after the procedure. This study demonstrated that age under 1 year and hydrocephalus caused by myelomeningocele, bleeding, and infection were considered independent risk factors of poor prognosis in ETV.
