INTRODUCTION: After a time of domination of shunt placement, endoscopic third ventriculostomy (ETV) has been increasingly applied in treatment of obstructive hydrocephalus. AIM: To assess the effectiveness of ETV in treatment of adults with three-ventricle hydrocephalus of different etiology. MATERIAL AND METHODS: Ninety-six patients with obstructive hydrocephalus were studied: 24 with primary aqueductal stenosis, 61 with brain tumor, and 2 with basilar tip aneurysm. In 9 patients the etiology of hydrocephalus remained undetermined. The assessment of treatment results was based on clinical and radiological criteria. RESULTS: Clinical improvement was observed in 74 (77.1%) patients, and radiological improvement in 52 (54.2%). One patient died. Follow-up of 24 patients with primary aqueductal stenosis has shown that in 20 (83.3%) of them clinical improvement has been stable, and in 14 (58.3%) radiological improvement has been observed. Two patients required shunt placement due to hydrocephalus recurrence 12–24 months after the ETV procedure. Among 9 patients with undefined hydrocephalus, 3 required shunt placement within 6 months after ETV (2 shunted previously). Endoscopic third ventriculostomy treatment in a patient with hydrocephalus caused by basilar tip aneurysm succeeded. The assessment of ETV effectiveness in oncological patients has been indirect in view of the underlying disease. CONCLUSIONS: The best results of ETV treatment have been demonstrated for patients with primary aqueductal stenosis. Ventricle size cannot determine the effectiveness of treatment as an individual requirement. Endoscopic third ventriculostomy is effective in previously shunted patients although the prediction of outcome should be cautious. Endoscopic third ventriculostomy enables preparation for further therapy and is palliative treatment in oncological patients with secondary hydrocephalus
