MATERIAL and METHODS: Pediatric and adult patients with symptomatic hydrocephalus treated with ETV during 11 years (2008?2019) in our clinic were retrospectively evaluated. Patients were divided into primary ETV group, in which ETV was the first method of hydrocephalus treatment, and secondary ETV group, in which cerebrospinal fluid (CSF) drainage procedures were initially attempted. Statistical data analyses were performed to compare the outcomes of primary and secondary ETV groups.

RESULTS: In total, 317 patients treated with ETV [140 (44%) patients aged 3?18 years and 177 (55%) aged 19?80 years] were followed-up for a mean duration of 60 months. Primary and secondary ETV groups comprised 207 and 110 patients, respectively. Further, 170 (82%) patients in the primary ETV group and fifty-nine patients (53%) in the secondary ETV group benefited from ETV. Primary ETV was associated with the highest probability of success (OR: 11.87). Increasing age (OR: 0.97) and male sex (OR: 4.719) increase the probability of achieving success. The overall prediction accuracy of the model was 72.2%. Kaplan?Meier survival analysis showed no significant difference between categorical groups in terms of time to failure (1.3 and 5 years), sex, ETV type, and categorized age (below 18 and above) (p > 0.05). Complications occurred during or after ETV in 14 patients.

CONCLUSION: Unlike most studies, our study includes both adult and pediatric groups. According to the findings obtained in our study, the recovery rate was higher in the primary ETV group (82%) than in the secondary ETV group (53%). According to the model we created, our prediction rate of recovery was 72%. Primary ETV, male sex, and advanced age are important predictors of success in ETV. Keywords : Hydrocephalus, Endoscopy, Third ventriculostomy, Primary ETV, Secondary ETV