Introduction: Endoscopic third ventriculostomy (ETV) is currently accepted as the first line of treatment in obstructive hydrocephalus.

Objectives: The objective of this study is to evaluate the success rate of this procedure in both adult and children and identify predictive success factors.

Material and methods: We reviewed medical charts of all consecutive cases of ETV performed in our institution from January 2010 to December 2015. Outcome (ETV success) was defined as the absence of reoperation or death attributable to hydrocephalus at 6 months.

Results: This study includes 43 primary ETVs. 18 patients were adults and 25 children, ages ranging from 1 month to 76 years. The mean age of the adult population was 52 years and paediatric population was 4 years. 12 patients were less than 2 years old. Overall success rate was 72%. Results were better in adult population (83%) compared to paediatric population (67%). Worse results were recorded in patients less than 2 years old (36%).The most frequent origin of hydrocephalus was benign aqueductal stenosis (48%) followed by tectal or non-tectal tumors (28%) and infection/haemorrhage (12%). 14% of the patients had previous ventricular shunts. Intra-operative haemorrhage rate was 5%. Overall mortality was 1%. Mean follow-up time was 21 months.

Conclusions: An overall high clinical success rate was achieved in the treatment of obstructive hydrocephalus with ETV in our series. Ventricular size reduction doesn’t seem to accurately correlate with clinical results. Patient’s age seems to positively influence outcome.