The number of deaths due to cerebrovascular disease is the third highest in the United States, with nearly 750,000 strokes each year, costing $45 billion to treat, and carotid occlusive lesions account for 25% of strokes. Epidemiological studies have shown that the prevalence of carotid stenosis is 0.5% in people over 60 years of age, rising to 10% in people over 80 years of age, with the majority of patients being asymptomatic. The incidence of cerebrovascular disease in China is 150-200 per 100,000 people, of which ischemic cerebrovascular disease accounts for 75%-85%. The three major randomized, controlled clinical trials, NASCET (North American Symptomatic Carotid Endarterectomy Trial), ECST (European Carotid Surgery Trial) and ACAS (Asmptomatic Carotid Atherosclerosis Study), have confirmed that carotid endarterectomy (CEA) is a better treatment for carotid stenosis than other medications. CEA reduces the risk of stroke in patients with symptomatic carotid stenosis with >70% stenosis and in men with asymptomatic carotid stenosis with >60% stenosis, and is the conventional treatment for severe carotid stenosis. However, the efficacy of CEA depends on the operator’s technique, and if the perioperative mortality rate exceeds 6% and 3% in symptomatic and asymptomatic patients, respectively, CEA treatment loses its significance for secondary stroke prevention. Many patients are forced to forgo surgical treatment because they cannot tolerate general anesthesia or are prone to complications or death due to concomitant heart disease, pulmonary hypoplasia, and renal insufficiency, and the procedure itself can cause the risk of myocardial infarction, deep vein thrombosis, and pulmonary embolism, with general anesthesia, improper intubation, and pneumonia also being potential complications. In the ECST trial, cervical incision and intraoperative traction caused 10% of the complications of cerebral nerve injury, local hematoma, and infection. In addition, dermal nerve injury from neck incision can cause skin numbness in the neck. In view of the above-mentioned drawbacks, CEA is not a perfect treatment method and a safer, effective and minimally invasive method is needed to replace it. CAS generally does not require general anesthesia, which facilitates the monitoring of changes in the patient’s condition during treatment; it is less painful for the patient; it has a shorter postoperative recovery time and less treatment cost; it avoids nerve damage, wound infection and neck hematoma due to carotid artery dissection; it can treat carotid and coronary artery lesions at the same time; and it can reduce the mortality rate of patients at high risk for CEA treatment. In this way, treatment possibilities are provided for patients who are not suitable for CEA treatment. However, different inclusion criteria for patients, different criteria for cure and complications, and observer bias make it difficult to compare the efficacy of CAS with that of CEA. large-scale clinical trial studies are needed to determine whether CAS treatment can replace CEA as a standard treatment option, as well as future improvements and innovations in CAS treatment devices, technology, and safety. CAS clinical trials and evaluation] Eleven large CAS studies have been published since 1996, and the differences and contradictions in sample populations, lesion characteristics, and revascularization techniques make it difficult to compare and analyze these results. However, all reported a success rate >95%, an operative mortality rate of 0.6% to 4.5%, a severe stroke incidence of 0% to 4.5%, a minor stroke incidence of 0% to 6.5%, and a 6-month restenosis rate of <5%. The CAVATAS (The Carotid and Vertebral Transluminal Angioplasty Study) is the first prospective, multicenter, randomized controlled study of the efficacy of angioplasty (PTA) compared with CEA. The study included 504 patients. A total of 504 patients were enrolled in the study and followed for 3 years, 20% of whom received stenting. There was no significant difference in the risk of treatment-related stroke or death between the two groups, with both groups causing 10% of strokes >7 days or deaths within 30 days after treatment and 6% of disabling strokes or deaths occurring within 30 days after treatment in both groups. Preliminary analysis of long-term survival showed no difference in the incidence of ipsilateral physical stroke or disabling stroke at 3 years after randomization to treatment. However, stroke or death within 30 days was significantly higher in both groups in the CAVATAS trial than previously reported, but not significantly different from the 7% reported in the ECST trial. The incidence of hematoma was 1.2% in CAS and 6.7% in CEA. Cerebral nerve damage and myocardial infarction occurred only in the CEA-treated group. Vitek et al. reported a study of 404 patients treated with carotid angioplasty and stenting, with a technical success rate of 98%, a 30-day mortality rate of 1.9%, a severe stroke rate of 0.7%, a minor stroke rate of 5.8%, and a restenosis rate of 5% (>50% stenosis). Complication rates were lower in the last 122 cases treated with CAS, suggesting an association with improved operative experience, with a minor stroke rate of 2.5% and no serious strokes or deaths. Wholey et al. reported the results of a single-center study of 540 carotid artery stenting, showing an overall stroke and mortality rate of 3.8% after CAS treatment. When the balloon-expandable Palmaz stent was selected early in the trial, bradycardia and hypotension occurred in 5.3% of patients due to the greater lateral force of the balloon-expandable stent, which enhanced pressure receptor stimulation, and 1.3% of these patients required temporary pacing and vasoactive drug therapy. The incidence of ipsilateral microstrokes was 16% in hypotensive patients compared with 3% in normotensive patients. Although bradycardia and hypotension are still seen with the current use of self-expanding stents for the treatment of occlusive carotid artery disease, the incidence is significantly lower than with balloon-expandable stents, and vasoactive drug support is rarely required. Stent implantation is contraindicated in patients with excessive blood pressure, and there is a risk of fatal reperfusion intracranial hemorrhage early after stent implantation. Vascular ultrasonography confirms that blood flow velocity is usually increased in the segment of the vessel in which the stent was implanted. The incidence of restenosis was 5.5% at 12 months of follow-up, with re-angiography required if the stenosis exceeded 70% and angioplasty required if the lesion was 75% stented. During the average follow-up period of 26 months, 3% of patients underwent revascularization due to restenosis. The CARESS (Carotid Revascularization with Endarterectomy or Stenting Systems) trial studied the same proportion of patients undergoing carotid endarterectomy or carotid stenting. 2000 patients were enrolled in this trial, with 1000 patients undergoing carotid endarterectomy or 1000 patients undergoing carotid stenting. The CARESS trial was designed to investigate the efficacy of carotid endarterectomy and carotid stenting, the only clinical study to include low-, intermediate-, and high-risk patients. The investigators were able to use one or more stents and distal protection devices in the preparatory phase, and according to the results of the worldwide registry, the perioperative stroke and mortality rate was 10% in medical centers with fewer than 50 CAS operations and 4% in medical centers with more than 300. The CREST (The Carotid Revascularlzation Endarterectomy versus Stent Trial) is a prospective, multicenter, randomized, controlled, NIH (National Institutes of Health) funded, corporate-supported study of the efficacy of CAS versus CEA, and is currently ongoing. Symptomatic patients with stenosis of more than 70% on ultrasound or 50% on angiography were randomized to CAS or CEA. To demonstrate a significant difference in clinical outcomes between the two treatment groups, the trial was proposed to include 2500 patients divided into two groups of 1250 each. A total of 60 treatment centers were established, each enrolling approximately 40 patients. the CREST trial was prepared by selecting the self-expanding nickel-titanium Acculink stent and the Accunet distal filter protection device (Guident). Data from 470 patients treated with CAS were retrospectively analyzed: 30% of patients were symptomatic, and 33% of these 30% met and 67% did not meet the inclusion criteria for the CREST trial, i.e., of 141 symptomatic patients, only 47 met the inclusion criteria for the CREST trial. Among those excluded were 16 patients with carotid resection, 9 patients with contralateral occlusive lesions, 12 patients older than 80 years with EF <30% heart failure, and 15 patients with valve disease or elective coronary artery bypass surgery. only 9.8% of the 470 patients treated with CAS met the CREST trial inclusion criteria. The SAPPHIRE (The Stenting and Angioplasty with Protection In Patients at High Risk for Endarterectomy) trial is also a randomized controlled study of the efficacy of CAS compared with CEA, including a group of patients with high risk factors for surgical treatment. 600 to 900 patients were proposed to be included in the SAPPHIRE trial for randomized study. The FDA classified patients as high-risk if they had previous endarterectomy for restenosis, ipsilateral stenosis with contralateral occlusion, previous radiation therapy, or conventional endarterectomy. lesions that are not easily accessible by conventional endarterectomy. In addition, patients with severe co-morbidities, including chronic obstructive pulmonary disease FEV <1, congestive heart failure, left ventricular ejection fraction <30%, unstable angina, multiple coronary artery lesions, renal insufficiency, and age over 80 years were classified as surgical high-risk patients. The lack of in-depth analysis of high-risk factors when the inclusion criteria were first developed led to the fact that patients with a combination of multiple causative factors who were in fact at great risk represented only a minority of all patients. Another group of high-risk patients that should have been included, such as those who refused surgery despite physician consent, was not enrolled, so the SAPPHIRE trial progressed slowly. 307 high-risk patients were randomized to CEA or CAS with distal protection devices. 7.3% in the CEA-treated group and 4.4% in the stent group, and the incidence of myocardial infarction was 7.3% in the CEA-treated group and 2.6% in the stent group.