Patient: Description of the condition (onset time, main symptoms, hospital visited, etc.): MRA of the head shows a C2 segment aneurysm of the left carotid artery, with a basal width of about 0.4 CM and a height of about 0.31 CM, should we do a DAS intervention, please. The C2 segment aneurysm is located in the skull. From your description, this aneurysm is very small, but it is common for small aneurysms to rupture in clinical practice. Many of the ruptured aneurysms we treat are less than 0.4 cm, and once the aneurysm ruptures, the death and disability rate is high. There is also some physician opinion that such aneurysms can be followed up because the likelihood of rupture is unlikely. the ISUIA study is based on foreign Caucasians, and there are differing opinions on this study, and there are no studies on unruptured aneurysms based on Chinese people. My personal opinion is that DSA is needed and if the aneurysm is diagnosed it can be treated with minimally invasive interventional methods.