Any surgery has risks, and the risks of intracranial stents are greater than those of other stents. The first common one is that there are no embolisms or blockages of small vessels, and there are also some patients with severe stenosis, so after reopening, will they develop hyperperfusion syndrome? What are the main manifestations of hyperperfusion syndrome? Some patients have sudden brain hemorrhage, cerebral edema, cramps, confusion, or hemiparesis, etc. This is one of the biggest risks of surgery. This is the biggest risk of intracranial stenting, including embolization of small blood vessels in the brain and bleeding from ruptured blood vessels, which are the two main risks. It also includes vasospasm, which leads to ischemia, many of which are transient and can be improved with medications. In some patients, it can lead to persistent symptoms, resulting in hemiparesis, which can also occur.