Carotid artery stenting has certain risks, especially for the plaque in the carotid artery belongs to soft plaque. At this time, through the stent placement surgery, the mesh of the stent cuts the soft plaque, causing the soft plaque to become tiny plaque and fall off into the lumen, which may lead to embolism of the cerebral artery with the blood flow, causing the patient to have symptoms of hemiplegia, such as weakness of one limb, aphasia, and blurred vision. Prior to surgery, a protective umbrella needs to be placed over the carotid artery to collect the ruptured plaque, which can prevent the occurrence of cerebral infarction. Not all plaques can be prevented from dislodging and causing a cerebral infarction, but the vast majority of plaques can be collected by the umbrella.