Cerebral aneurysm is a serious life-threatening disease. According to statistics, the mortality rate after the first rupture of cerebral aneurysm is as high as 30-40%, and reappearance of the problem can occur in 1/3 of patients. Cerebral aneurysm is not a tumor Cerebral aneurysm is not a tumor in the true sense, it is a local weakness of the cerebral artery blood vessel wall and produces aneurysmal protrusions, which tend to occur at the branches of the cerebral artery bifurcation and main trunk. Due to the congenital defects of the muscle layer of the cerebral artery wall, and the fact that this is the place where the blood is most impacted, the pressure and impact of long-term blood flow cause the weak point of the cerebral artery wall to protrude outward and gradually expand, thus forming a cerebral aneurysm. Hypertension, atherosclerosis, trauma and infection are also associated with the occurrence and development of cerebral aneurysms. More than 90% of small and medium-sized cerebral aneurysms are asymptomatic until they rupture and bleed. A small number of patients may have recurrent mild headache attacks, but they are not known because of their low clinical specificity and insidious condition. The presence of cerebral aneurysm can be recognized only when the aneurysm compresses the adjacent nerves and produces obvious symptoms, such as inability to raise the eyelids, eye abduction, pupil dilation, and eye protrusion. High mortality rate of ruptured cerebral aneurysm Cerebral aneurysm is a high-risk, disabling and fatal disease, mainly with the risk of bleeding from ruptured aneurysm and cerebral ischemia due to vascular spasm, both of which are fatal dangers. A cerebral aneurysm is like a balloon blown up in the wall of a cerebral blood vessel, which may rupture at any time. When a cerebral aneurysm ruptures and bleeds, the bleeding is mainly concentrated on the surface of the base of the brain, called subarachnoid hemorrhage. 85% of subarachnoid hemorrhage is caused by a ruptured cerebral aneurysm. Once a cerebral aneurysm ruptures, it often manifests as severe headache, vomiting, and even unconsciousness and death,. CT scan can show the presence of subarachnoid hemorrhage and determine the location of cerebral aneurysm based on the location of the hemorrhage. It is very important to determine the exact location, morphology, internal diameter, number, vascular spasm and surgical plan. Most cerebral aneurysms that rupture and bleed are temporarily stopped by a clot, and the condition gradually stabilizes. However, as the clot around the rupture dissolves, the aneurysm may rupture and bleed again. About 70% of patients treated conservatively will die from cerebral aneurysm rebleeding. According to statistics, 40% to 50% of patients will have a second rupture within one month after the rupture, and the mortality rate is about 70% after the second rupture and almost 100% after the third rupture. Once a cerebral aneurysm is diagnosed, it should be aggressively treated surgically for its eradication. The fundamental aim of treatment is to prevent the cerebral aneurysm from rupture and bleeding again. There are two main surgical treatments for cerebral aneurysm, one is craniotomy to clip the cerebral aneurysm, that is, to clip the cerebral aneurysm neck with a special cerebral aneurysm clip, and to protect the patency of the aneurysm-carrying cerebral artery. The cavity of the cerebral aneurysm is filled until the aneurysm is completely occluded, so that it will not rupture and bleed again, thus achieving the purpose of cure. Craniotomy clamping of cerebral aneurysm is effective, but the surgery is traumatic and recovery is slow. The advantages of endovascular intervention compared with craniotomy are that it is less traumatic, faster recovery, easy to be accepted by patients and their families, and can be tolerated by elderly and sick people. However, the disadvantages of endovascular interventions are high cost.