Carotid artery stenosis Among cerebrovascular accidents, ischemic stroke (including transient ischemic attack, cerebral infarction) accounts for 75-90%. The main cause of ischemic stroke is ischemia or even necrosis of brain tissue due to carotid artery stenosis and occlusion. Carotid artery stenosis greater than 50% is not treated by internal medicine alone. Carotid artery stenosis and occlusion are caused by the presence of plaque in the carotid artery, just like the blockage in the sewer pipe. It is most common in people over 40 years old who have three highs (hypertension, diabetes mellitus, hyperlipidemia), addiction to alcohol and tobacco, and addiction to greasy food. Transient ischemic attack (TIA) is a medical condition called transient ischemic attack. It is a sudden, transient, reversible neurological dysfunction caused by focal cerebral ischemia due to transient lack of blood supply in the cerebral arteries. The common manifestations are transient numbness or weakness in the arms and legs, with episodes lasting from a few seconds to ten minutes, or transient blurred vision, blackness, transient unclear speech or inability to speak. TIA symptoms usually recover on their own within 30 minutes and fully recover within 24 hours without sequelae. About 1/3 of untreated patients will have cerebral infarction, 1/3 can have recurrent attacks, and 1/3 can resolve on their own. Cerebral infarction Numbness, weakness, and slurred speech in hands and feet persist, do not recover within 24 hours, and may worsen within hours and 3 days. There is usually no headache, no coma, and no vomiting. If left untreated it can lead to permanent limb numbness and weakness, slurred speech and other symptoms, resulting in disability. Death from coma may occur in a small number of patients. Surgical methods: Carotid endarterectomy (CEA): It is a method to remove the thickened carotid endarterectomy atherosclerotic plaque to prevent cerebral infarction due to plaque detachment, and has been proved to be an effective method to prevent and treat ischemic cerebrovascular diseases. The procedure is performed under general anesthesia, and an incision is made at the anterior border of the sternocleidomastoid muscle in the anterior part of the neck to separate the common carotid, internal and external carotid arteries, temporarily block the above-mentioned vessels and then incise the bifurcation of the common carotid artery to remove the thickened intimal plaque and re-suture the vessel wall. The occurrence of cerebral ischemia is monitored intraoperatively using electroencephalography, etc. If there is a manifestation of cerebral ischemia, a diversion tube can be used to temporarily divert blood to ensure cerebral blood supply. This procedure has been performed in Europe and the United States for 60 years and has been proven to be a very safe and effective procedure, the gold standard for the treatment of moderate to severe carotid stenosis, with approximately 150,000 cases performed each year in the United States alone. Carotid artery stenting is not the treatment of choice due to the high cost, high incidence of perioperative stroke, and high rate of postoperative restenosis. Diagnosis: Any middle-aged or elderly patient with risk factors such as triple high (hypertension, diabetes mellitus, hyperlipidemia) and addiction to alcohol and tobacco, especially those with ischemic stroke manifestations, such as transient aphasia, numbness, weakness, monocular blindness and other episodes. Investigations: Carotid ultrasound, CT angiography (CTA), magnetic resonance angiography (MRA), cerebral angiography (DSA), any of the above may be indicated. Indications: Symptomatic patients with carotid stenosis greater than 50%; asymptomatic patients with carotid stenosis greater than 60% and a life expectancy of 5 years or more.