, MD,

Abstract- Background: Chronic shunt-dependent hydrocephalus is a complication of aneurysmal subarachnoid hemorrhage (aSAH). Its incidence and risk factors have been described while the hydrocephalus onset in terms of days after treatment (microsurgical or endovascular) has not been yet analyzed. Materials and Methods: 45 patients, treated for aSAH in 4 Italian Neurosurgical Departments, were retrospectively analyzed. It was calculated the time that elapses between treatment and hydrocephalus onset in 36 patients. Results: Of the 45 shunted patients, 15 (33.3%) were included in the microsurgical group (group A) and 30 (66.6%) were in the endovascular one (grou