The goal of this prospective observational cohort study is to learn about treatment strategies for unruptured intracranial aneurysms in the Chinese population. The main questions it aims to answer are:

• To establish a cohort of patients with intracranial unruptured aneurysm and explore the optimal clinical treatment strategy.
• To establish clinical management path for patients with unruptured intracranial aneurysm.

According to the treatment of all patients with unruptured intracranial aneurysm, they were divided into the following groups: 1. Conservative treatment group; 2. Intracranial aneurysm clipping group; 3. Coil embolization or stent-assisted coil embolization group; 4. Flow diversion group.

Inclusion Criteria:

A. age > 18 years. B. at least one intracranial aneurysm needs to be treated by craniotomy, endovascular treatment or combined surgery.

C. patients' consent were obtained.

Exclusion Criteria:

1. Ruptured intracranial aneurysms, accompanied by subarachnoid hemorrhage or cerebral hemorrhage ;
2. Traumatic, infectious and atrial myxoma-associated intracranial aneurysms ;
3. Combined with cerebrovascular malformations;
4. Combined with brain tumors or malignant tumors in other parts ;
5. Combined with systemic connective tissue disease and systemic rheumatic disease ;
6. Due to other diseases, or poor general condition, the expected survival time is not more than 12 months ;
7. During pregnancy and perinatal period.

Patients with unruptured intracranial aneurysm