Carotid artery stenosis is common in elderly people with atherosclerosis, and it is documented that one quarter of strokes are caused by carotid artery stenosis. In general, patients with carotid artery stenosis of more than 75% have a 2-5% chance of having a stroke in the first year, which may be manifested by hemiparesis, hemianesthesia or hemianopia. After the first symptom of cerebral ischemia, there is a 13% chance of stroke in the first year. In the past, surgical carotid endarterectomy was the standard treatment for carotid artery stenosis, but with the development of cardiac coronary angioplasty and advances in endovascular stenting, angioplasty has been further applied to patients with carotid artery stenosis. Today, carotid angioplasty and carotid stenting are emerging techniques in the treatment of carotid stenosis. In the past, traditional carotid stenting had many advantages compared to surgical carotid endarterectomy, such as high success rate, less invasive, fewer complications, lower restenosis rate and shorter hospital stay. However, the incidence of postoperative temporary cerebral ischemia and stroke is similar to that of surgical procedures (approximately 6%). The reason for this is that the small atherosclerotic plaque that is removed during carotid stenting blocks the distal cerebral vessels. In recent years, the invention of distal brain protection devices has significantly reduced the complications of stroke (about 3%) by intercepting the small atherosclerotic plaques that are stripped during the procedure, making carotid angioplasty and carotid stenting safer. This makes carotid angioplasty and carotid stenting safer and provides greater assurance of patient care.