Introduction: Aneurysmal subarachnoid hemorrhage (SAH) is a devastating form of stroke, which often causes acute hydrocephalus requiring the insertion of an external ventricular drain (EVD). A major complication of aneurysmal SAH is delayed cerebral ischemia (DCI), which corresponds to the occurrence of an ischemic stroke up to 21 days after the aneurysm rupture. There are currently only few ways to prevent it. As DCI is linked to the presence of blood within the subarachnoid space, it has been hypothesized that removing this blood may decrease the risk of DCI. It could be obtained by injecting a fibrinolytic agent through the EVD, a therapeutic strategy named intraventricular fibrinolysis (IVF). There are several evidences, both in preclinical and in clinical studies that IVF controls the phenomenon that are leading to DCI. It has notably been shown in Phase I and Phase II trial that IVF in aneurysmal SAH is safe and may decrease the risk of DCI, with a trend to improve the rate of good functional outcome by about 10%. Here, the investigators propose to conduct a phase III trial to provide a clear evaluation of the impact of IVF after aneurysmal SAH.