Today, stent implantation under the internal carotid artery cerebral protection device was performed under local anesthesia. The patient was lying down, the right femoral vein was punctured by Dr. Peng Zhou of the Department of Cardiology, and a temporary pacemaker was placed, after which a right femoral artery was punctured at the body projection of the right inguinal femoral artery. The remaining artery was normal. In view of these findings, the 5F short sheath was replaced with an 8F short sheath, through which a guiding catheter was introduced into the aortic arch, a simmon1 catheter was selected to enter the left CCA, and a guiding catheter was placed in the proximal bifurcation of the CCA, through which an Angioguard umbrella was introduced through the distal end of the stenotic segment of the left ICA near the lumen of the normal vessel and opened, and an Angioguard guidewire was introduced through the An 8-4 Pricise stent was introduced through the Angioguard guidewire, which completely covered the left ICA stenosis, i.e., the ulcer foci, and then released. The operation went smoothly, and the patient had no complaints of discomfort during the operation. Postoperative management: After the ACT was nearly normal, the short sheath was removed. Note any neurological changes and any abnormalities in the right lower limb.