Endovascular coiling has become a strategy of choice of intracranial aneurysms due to its minimally invasiveness. However, there has few prospective randomized controlled studies on the comparison of therapeutic effect between endovascular coiling and microsurgical clipping, especially the latter via keyhole approaches, which has been widely used in recent years. Based on the data of a single center, a randomized controlled study was conducted on patients with ruptured anterior circulation aneurysms suitable for both endovascular and extravascular treatment, including endovascular coiling, microsurgical clipping via conventional craniotomy and keyhole approaches, in order to compare the efficacy of the above strategies and provide more objective basis for treatment selection for operators.

Consecutive patients of a single center will be screened. If spontaneous subarachnoid hemorrhage (SAH) is confirmed by head computed tomography (CT), a diagnostic CT angiography (CTA) or digital subtraction angiography (DSA) will be carried out emergently. A patients harbored a single intracranial aneurysm of anterior circulation that resulted in SAH will be concerned. Based on the assessment of condition, the patient will enrolled into this study without indication of decompressive craniectomy. The enrolled patients will be divided randomly into 3 groups, who experienced endovascular coiling, microsurgical clipping via conventional craniotomy and via keyhole approaches. All of these treatment will be conducted by a same senior neurosurgeon. CTA or DSA were followed up regularly. The occlusion rate, operative period, hospitalization duration and cost, surgical complications were compared and analyzed.

Inclusion Criteria:

• Single intracranial anterior circulation aneurysm diagnosed by CTA or DSA
• CT showed that subarachnoid hemorrhage originated from the rupture of the aneurysm and was confirmed during operation
• No indication of decompressive craniectomy (Hunt-Hess grade ≤ 4, Glasgow Coma Scale ≥ 7, no brain herniation; CT showed midline displacement < 5mm)
• The aneurysm is suitable for both endovascular treatment and microsurgical clipping

Exclusion Criteria:

• The patients and their families did not agree to join the study
• Patients with unruptured anterior circulation aneurysms
• Patients with posterior circulation aneurysms
• Patients with multiple intracranial aneurysms
• Those who cannot receive treatment due to serious concomitant diseases