aSAH Treatment Based on Intraventricular ICP Monitoring: A Prospective, Multicenter, Randomized and Controlled Trial

Inclusion criterias 1. Definite diagnosis of aSAH: presence of SAH symptoms confirmed by CT, with rupture of an intracranial aneurysm identified by CTA or DSA. The ruptured aneurysm is scheduled for definitive treatment (clipping or endovascular therapy) within 72 hours of onset. 2. Age ≥ 18 years. 3. Symptom onset within 72 hours. 4. Hunt-Hess grade 2-4 and modified Fisher grade 2-4 on CT imaging. 5. Written informed consent obtained from the participant or legal representative. Exclusion criteria included 1. Pregnancy or lactation; 2. Bilateral fixed dilated pupils on admission; 3. Malignancy, bleeding disorders, or other severe systemic comorbidities, including chronic obstructive pulmonary disease, multiple organ dysfunction, severe diabetes, heart failure, or chronic kidney disease; 4. Pre-existing neurological disability due to previous brain disease or neurosurgery, defined as a premorbid modified Rankin Scale (mRS) score ≥3; 5. Significant structural abnormalities on neuroimaging, such as extensive encephalomalacia or marked mass effect; 6. Subarachnoid haemorrhage caused by non-aneurysmal aetiologies; 7. Moyamoya disease associated aneurysmal rupture; 8. Other underlying diseases expected to substantially affect prognosis; 9. Active request for ICP monitoring by the patient or family; 10. Any other condition considered unsuitable for enrolment by two investigators; 11. Concurrent participation in another clinical trial.