The treatment of atherosclerotic carotid stenosis, a major cause of stroke (10-20% of strokes), has been a hot topic of global interest for many years. The traditional treatment has been conservative medical therapy, but several randomized controlled studies over a decade ago showed that carotid endarterectomy was superior to conservative treatment in preventing stroke, establishing CEA as the standard of care for carotid atherosclerosis. These studies include the North American Symptomatic Carotid Endarterectomy Trial (NASCET), the European Carotid Stenosis Trial (ECST), the Asymptomatic Carotid Stenosis Trial (ACAS), and the Asymptomatic Carotid Stenosis Trial (ACST). Although CEA is effective in preventing strokes caused by carotid stenosis, it is a major procedure that requires general anesthesia and is limited by many factors, such as the patient’s age, heart, liver and kidney function, etc. In all CEA studies, high-risk patients like these were excluded. In 1989-1990, Mathias et al. were the first to perform stenting of carotid stenotic lesions using the Wallstent stent, Theron et al. were the first to use the Streker stent, and Diethrich et al. were the first to perform carotid stenting using the Palmaz stent in 1993. In the following decade, with the improvement of technology and the emergence of new materials, many scholars carried out studies on carotid stenosis stenting (CAS , Carotid Angioplasty with Stents). In particular, the advent of protective devices has reduced the risk of intraoperative plaque dislodgement causing distal intracranial vessel occlusion (from 5% to 2%). These results have led to a lot of confidence that CAS can be an alternative to CEA in many ways, especially in patients who are not suitable for CEA treatment, but most of the studies are not randomized prospective studies and there is a lack of evidence based on evidence whether CAS has a similar or even better efficacy than CEA. For this reason, randomized controlled studies of CEA and CAS have been conducted in many centers to demonstrate that CAS has similar efficacy and risk to CEA. International randomized controlled studies have been completed and are ongoing, including the Protected Device Stenting and Endarterectomy in High Risk Patients Randomized Controlled Study (SAPPHIRE), the Carotid Endarterectomy and Stent Reconstruction Trial (CARESS), the Carotid and Vertebral Artery Stenosis Stenting and Surgical Treatment Study (CAVATAS), the Carotid Endarterectomy and Stenting Trial (SPACE) and the Carotid Revascularization Endarterectomy and Stenting Trial (CREST). The EVA-3S study in this paper is one such study. SAPPHIRE (Stenting and Angioplasty with Protection in Patients at High Risk of Endarterectomy) is a company-funded, prospective, randomized, controlled study. The study selected patients with high-risk carotid stenosis for a randomized controlled trial of CAS and CEA, and the 30-day postoperative results suggested significantly lower adverse outcomes in the CAS group (5.8%) than in the CEA group (12.6%). Its publication in the New England Journal of Medicine has been widely cited, even inappropriately. We should find that the majority of patients included in the study were asymptomatic, with less than 30% being symptomatic. Approximately 30% of patients who had previously undergone CEA and 30% of those who had undergone angioplasty had restenosis observed late in the study and were treated again, but the odds of embolism triggered by smooth restenosis and rough atheromatous plaque were actually different, and the risk of reoperation was thought to be higher, with no evidence that treating restenosis was beneficial. The study was also not completely randomized; 334 patients were randomized to the group, but 413 were not. It is also a major regret that SAPPHIRE ended prematurely because not enough patients entered the study, leaving the subgroups without sufficient data for analysis. Because of its many shortcomings, the study has been criticized by many scholars for the reliability of its conclusions despite being the first large controlled study to be reported, particularly the close relationship between the investigators and Cordis, the manufacturer of the stent and protection device. CARESS was organized as a study by the International Association of Endovascular Specialists and was randomized to control the outcome of treatment with CAS and CEA. This study showed that the 30-day stroke incidence and mortality rate was 2% in both groups of patients. The 1-year results of this study showed that the difference between the two groups was not significant (CAS 10%/CEA 13.6%). It was concluded that the incidence of stroke and mortality at 30 days was the same for CAS with a protective device as for CEA. Unlike SAPPHIRE, not only high-risk patients were included in the CARESS trial, but also all patients. CAVATAS (Carotid and Vertebral Artery Transluminal Angioplasty Study ) involved 504 patients with or without symptomatic carotid stenosis at 24 medical centers, compared with CEA versus CAS with or without a protective device, with primary observations including procedure-related disability, lethality, and restenosis rates at 3 years. The data showed no significant differences in survival and stroke risk between the two groups (disabling stroke and mortality of 6.4% and 5.9%, respectively). patients in the CEA group had a significantly higher risk of cerebral nerve palsy and hematoma formation than those in the CAS group, which had a higher restenosis rate. A randomized controlled study of the carotid arteries (CAVATAS-2) was designed to compare the two treatments in high-risk patients based on a previous trial, and to date, only about 300 patients have been enrolled, but no conclusions have been drawn. SPACE [8], funded by the German Ministry of Health, is a prospective, randomized, controlled multicenter study looking at 1900 patients with severe symptomatic carotid stenosis (stenosis >70% by ultrasound, >50% by NASCET criteria, >70% by ECST criteria), but no results are available. CREST is a randomized controlled study of CEA and CAS with a protective device in patients with symptomatic carotid stenosis, conducted by the American Association of Stroke and Neurological Disorders. This trial involved multiple centers in North America and was designed to look at 2,500 patients, and when the results of the ACST study were published, the CREST study included patients with asymptomatic carotid stenosis rates of >60% angiographically and >70% ultrasonographically. This study is currently ongoing. In China, CEA has not received sufficient clinical attention and no large-scale clinical studies have been reported. However, with the development of CAS, the use of this technique is becoming more and more sophisticated. Various centers have published their own encouraging research results. In 1992, the Ministry of Health of China organized a multicenter randomized controlled study of CAS and CEA (TESCAS-C study) as part of the national “Tenth Five-Year Plan” project. The study was led by Xuanwu Hospital of Capital Medical University and included seven clinical centers in China, including Changhai Hospital of Second Military Medical University. Preliminary results showed that the total complications of CAS and CEA at 6 months were similar (9.8%/10.7%). The New England Journal of Medicine published the results of the French Ministry of Health-sponsored EVA-3S (Endarterectomy versus Stenting in Patients with Symptomatic Severe Carotid Stenosis) study in October of this year, confusing many proponents of CAS, as this is the first randomized controlled study of CAS and CEA with negative results to date. This was a public-funded, randomized controlled trial that included 20 academy-based and 10 non-academy-based study centers in France. As in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) study, patients included were required to be 18 years of age or older, have had a transient ischemic episode in one hemisphere or retina within 120 days prior to inclusion, or have a history of non-disabling stroke (or retinal infarction) with 60-99% symptomatic carotid stenosis. At the beginning of the trial, patients with stenosis of 70% or more were prescribed for surgery. Subsequently (in October 2003), as endarterectomy proved beneficial in patients with 50-69% stenosis, this criterion was changed to a stenosis of 60% or greater. Ipsilateral carotid stenosis of 60% or greater was confirmed by angiography or angiographic ultrasound and magnetic resonance angiography (MRA). Patients with one of the following conditions were excluded: modified Rankin score greater than or equal to 3 (disabling stroke), non-atherosclerotic carotid artery disease, severe multiple lesions of the same vessel (stenosis of the proximal common carotid artery, or stenosis of the intracranial artery more than the carotid segment), previous revascularization for symptomatic stenosis, history of bleeding disorders, uncontrolled hypertension or diabetes mellitus, unstable angina pectoris, and the presence of heparin. unstable angina, contraindications to heparin, ticlopidine or clopidogrel, expected survival of less than 2 years, and percutaneous or surgical interventions within 30 days before or after the study. The demonstration of stenotic lesions by angiography was not a factor in patient selection. Patients who were suitable for both treatments were randomly assigned to decide to receive treatment with endarterectomy or stenting. Randomization was done by each center, and a computer-generated randomized series consisting of randomly divided groups of 2, 4, or 6 patients was generated, and patients were classified according to the different study centers and the degree of stenosis (≥90% stenosis or <90% stenosis). Although the aim of the trial was to evaluate the safety feasibility of stenting, the results observed suggest that stenting poses a greater risk than endarterectomy. 30-day incidence of any stroke or death was 3.9% (95% CI 2.0-7.2) after endarterectomy compared with 9.6% (95% CI 6.4-14.0) after stenting, with a relative risk of 2.5 ( 95% CI of 1.2-5.1). The absolute risk increased by 5.7%, that is, one stroke or death per 17 patients stented compared with endarterectomy, and the incidence of disabling stroke or death at 30 days was 1.5% (95% CI 0.5-4.2) after endarterectomy and 3.4% (95% CI 1.7-6.7) after stenting, with a relative risk of 2.2 (95% CI 0.7-5.1). 95% CI of 0.7-7.2) (see Table 3). A higher proportion of strokes occurred on the day of surgery in the stenting group than in the endothelial stripping group (P=0.05). The study concluded that the study showed a significantly higher incidence of 30-day stroke or death after stenting (9.6%) than after endografting (3.9%), with a relative risk of 2.5 (95% CI 1.2-5.1). In addition, based on the observed incidence of the primary endpoint event, it is expected that the trial will have difficulty confirming that the risk of stenting is not higher than that of endothelial stripping. The EVA-3S study is the first randomized controlled study with a negative outcome to date and is arguably a no-brainer for CAS, which is now gaining momentum. There were no strict requirements for the physician performing the intervention in this study, although data analysis showed no significant correlation between this and the outcome of the procedure, leaving many to suspect that the proficiency of the procedure greatly influenced the results of the study. On the other hand, this is not necessarily a good thing; whether CAS is comparable to, or even a substitute for, CEA is not well documented by fumigation medicine and is not conclusive, and it is not advisable to blindly expand its application, especially when the level of proficiency greatly influences the risk of the procedure. The results of the EVA-3S study are nothing less than a shot of sedation to the current CAS fever, allowing everyone to calmly analyze the pros and cons of this technique. Although the many single-center prospective or retrospective reports of the results are good, they are after all insufficient to form a first-tier evidence of evidence-based medicine, and factors such as the skilled operation of interventionalists and careful patient selection in these centers are the basis for their optimistic results. Moreover, there are some problems in the practical application of this technique, including the selection of indications for the procedure, the management plan for bilateral arterial stenosis, the risk of protective device application, the use of antiplatelet aggregation drugs before and after the procedure, and the prevention and management plan for complications, which need further study. Intracranial artery stenosis is another major cause of recurrent stroke, with 40,000-60,000 new episodes of stroke related to intracranial artery stenosis each year in the United States, accounting for about 10-20%. The literature reports intracranial artery stenosis as a major cause of stroke attack or reoccurrence in Asian countries. According to the 2004 Chinese cerebrovascular disease guidelines, it is assumed that 2 million new stroke patients occur each year in China, of which 70% are ischemic strokes, and 30%-70% of ischemic strokes are related to intracranial artery stenosis, so there should probably be 400,000-500,000 new strokes related to intracranial artery stenosis each year in China, 10 times more than in the United States. The causes of intracranial artery stenosis are not well understood, and few targeted studies have been reported. Many conclusions come from hypothesis or extrapolation, and direct evidence is scarce. The limited literature reports also suggest that intracranial artery stenosis is the main cause of stroke episodes in Chinese. Angiographic analysis of 1500 patients with ischemic cerebrovascular disease at Xuanwu Hospital from May 2001 to May 2005 showed 850 cases (56.67%) of intracranial artery stenosis, including 250 cases of middle cerebral artery stenosis, accounting for 29.41% of the overall intracranial artery stenosis. Data from Xuanwu Hospital showed that 27% of intracranial artery stenosis was associated with diabetes alone, 39% with diabetes combined with hypertension, 21% with hyperlipidemia, and 47% with unclear causes, including 78% with unclear causes in patients under 45 years old. Xu Anding et al. showed that abnormal lipid metabolism is a risk factor for vascular disease, and high TC, TG, LDL-C, Lp(a), apoB levels and low apoA/apoB ratio are proatherosclerotic factors in a group of hypertensive patients with intracranial artery stenosis. The study showed that patients in the asymptomatic intracranial artery stenosis group had significantly higher blood TC, TG, LDL-C, and apoB levels and a significantly lower apoA/apoB ratio. There are few studies on immunology, serum biochemistry, and genetics of the national system of patients with intracranial artery stenosis. The literature on natural mechanisms of intracranial artery stenosis has reported a significantly higher rate of stroke in patients with intracranial artery stenosis.The EC/IC study [5] showed an annual stroke rate of 7.8% for middle cerebral artery stenosis.Thijs and Albers evaluated stroke recurrence in 52 patients with symptomatic intracranial artery stenosis and showed that 29 patients (56%) were treated with antithrombotic therapy (warfarin, heparin, or heparin). (warfarin, heparin, or antiplatelet agents), and 15 of the 29 patients (52%) had a recurrent stroke within a mean of 36 days, 8 of which were major stroke episodes or deaths. Several prospective studies have shown that intracranial artery stenosis is an important cause of stroke recurrence [15-17], showing mean annual rates of death and ipsilateral stroke of 4.7%-17.2% and 3.1%-7.6%, respectively. Although these studies have inevitable limitations due to small sample size and biased sample selection, further studies on the natural mechanisms of intracranial arterial stenosis are necessary. There are four hypotheses for the mechanism of ischemic stroke caused by intracranial artery stenosis: (1) stenosis causes hypoperfusion: when the stenosis is high, the collateral circulation cannot compensate and the distal blood flow decreases, then the cerebral vascular autoregulation function makes the blood vessels reflexively dilate, and the brain parenchyma also actively increases the amount of oxygen drawn from the blood to maintain the normal metabolic function of the brain. Once this compensation fails to maintain the metabolic demand of the brain, stroke will occur. These patients are well suited for interventional treatment. (2) Plaque rupture causing thrombosis at the stenosis site: rupture of pre-existing plaque, rough inner surface of plaque, lipid core, etc. are all contributing factors to thrombus formation. Such patients can receive antithrombotic and lipid regulating treatment to prevent thrombus formation and stabilize plaque, and thrombolytic treatment is feasible for acute onset. (3) Distal embolism caused by dislodgement of emboli at the plaque site: ruptured plaque contents or thrombus at the plaque site can be dislodged and become emboli to embolize the distal vessels. These patients have rapid onset and can receive thrombolytic therapy. (4) Occlusion of small penetrating arteries at the plaque site: There are many central branch arteries near the ring of Willis supplying deep brain structures, such as thalamus and basal nucleus, and there are also penetrating branches of basilar artery supplying brain stem. These patients also need to be carefully examined before undergoing intervention to avoid occlusion of the opening of the penetrating branch after treatment. As with peripheral and coronary atherosclerosis, pharmacological treatment of intracranial atherosclerosis focuses first on controlling risk factors, such as antithrombotics, statin lipid-lowering drugs, and angiotensin-converting enzyme inhibitors. Antiplatelet therapy and anticoagulation are the most commonly used treatments, with aspirin and warfarin being the most commonly used drugs, and both treatments have been controversial in clinical practice. The WASID study (Warfarin vs aspirin for symptomatic intracranial disease) is a classic study examining the pharmacological treatment of intracranial arterial stenosis, which included 2 components to evaluate warfarin and aspirin for the treatment of atherosclerotic intracranial stenosis. The first study was a retrospective analysis of patients with angiographically confirmed intracranial artery stenosis from 1985 to 1991 in all study centers with symptomatic intracranial artery stenosis greater than 50%, for whom the use of aspirin or warfarin was effective in the records of the internist. At a mean follow-up of 14.7 months, there were 8.4% of stroke episodes or deaths in the warfarin-treated group, compared with 18.1% of major stroke episodes or deaths in the aspirin group at a mean follow-up of 19.3 months. Nine percent of these were in the same vascular region. In the posterior circulation group of 100 patients with a mean follow-up of 13.8 months, the annual stroke attack rate was moderately 10.7% in the basilar artery stenosis region and 7.8% in the vertebral artery system. Based on this retrospective analysis, the study team designed a subsequent multicenter, randomized, double-blind controlled study (the Post-Warfarin Aspirin Study of Symptomatic Intracranial Artery Stenosis, a study of 59 centers in North America, 1998-2003, enrolling patients with angiographically confirmed intracranial artery stenosis greater than 50% in patients with TIA or mild stroke who received warfarin (INR control). The patients were treated with warfarin (INR control 2.0 to 3.0) or aspirin (1300 mg/d). However, due to safety concerns with warfarin, the study was terminated early after treating 569 patients (mean follow-up 1.8 years). Preliminary study data showed that the annual stroke attack rate was 12% in the aspirin-treated group and 11% in the warfarin-treated group in the narrow vessel region. In terms of the study's observed endpoints (complications such as ischemic stroke, cerebral hemorrhage, and death from other non-stroke cerebrovascular factors), there was no significant difference in effect between aspirin and warfarin (22.1% vs. 21.8%); although the incidence of ischemic stroke was similar, the incidence of cardiovascular events was significantly higher in the warfarin group than in the aspirin group, which contributed to the early termination of the study; the aspirin The rates of death in the aspirin and warfarin groups were 4.3% and 9.7%, respectively, but this difference was mainly due to nonvascular factors; the rates of bleeding in the two groups were 3.2% and 8.3%, respectively, which were significantly different; the incidence of ischemic stroke and major cardiovascular events was higher in the warfarin group with an INR below 2.0 than in those with an INR between 2.0 and 3.0, and the risk of bleeding was increased above the treatment standard. The risk of bleeding was increased above the treatment standard; the dose of anticoagulants used was difficult to control precisely and the INR was highly variable. In view of this, the study group concluded that aspirin is more effective than warfarin in the treatment of intracranial artery stenosis, but the efficacy of both is not very satisfactory. A single-center, non-randomized, controlled, prospective study being conducted at Xuanwu Hospital is ongoing, and preliminary results show that antithrombotic therapy remains effective in younger non-atherosclerotic stenoses with better collateral circulation and a better prognosis, with a total of 57 patients currently followed for 2 months-4 years without recurrent strokes. The main surgical treatment for patients with intracranial artery stenosis is Extracranial to Intracranial Bypass (EC/IC). 1985, the EC/IC Bypass Study Group published the results of its prospective international multicenter study [5], which included 1377 patients in an attempt to confirm the efficacy of bypass surgery for intracranial artery stenosis or occlusion, but the results of each groups confirmed ineffective results, especially in the middle cerebral artery group. As a result, there are no international surgical guidelines for intracranial artery stenosis to date. Many scholars believe that the design of previous studies had many shortcomings, notably the study groups did not evaluate well hypoperfused hemodynamic TIA or stroke episodes. A re-evaluation of the effectiveness of bypass surgery is recommended, and bypass surgery is back in the consideration of neurosurgeons. Endovascular treatment techniques developed in recent years have opened up new treatment options for intracranial artery stenosis. Since intracranial artery stenosis accounts for the major cause of stroke episodes in the fittest nation, research on endovascular treatment of intracranial artery stenosis has been very rapid in the last few years. The number of cases in several large centers in China is around 300, but the follow-up work is very unsatisfactory, and it is difficult to come to a recognized conclusion, there is no unified standardized treatment plan, and there is a lack of multicenter randomized controlled studies. However, due to the lack of evidence-based medicine and a promotion platform in line with national conditions, the implementation process is still unsatisfactory. The American Society of Interventional and Neuroradiology published a statement on angioplasty and stenting for atherosclerotic intracranial artery stenosis in 2005, suggesting through a review of the literature that angioplasty may be an option for atherosclerotic intracranial artery stenosis greater than 50% when conservative medical treatment is ineffective. The US 06 Stroke Guidelines also suggest that the effectiveness of endovascular treatment (angioplasty and/or stenting) in patients with intracranial stenosis with hemodynamic abnormalities where pharmacological treatment (antithrombotics, statins, treatment of other risk factors) does not provide symptomatic relief is uncertain, but further studies can be performed. Hankey et al [19] performed a retrospective evaluation analysis of current intracranial artery stenoplasty worldwide, and after summarizing a total of 79 relevant articles, the overall perioperative complications with stenting or balloon dilation alone were 7.9% (95% CI, 5.5% to 10.4%), perioperative mortality was 3.4% (95% CI, 2.0% to 4.8%), and perioperative stroke attack or mortality was 9.5% (95% CI, 7.0% to 12.0%) in a systematic review study that found no real with To date, there have been 2 randomized controlled studies of angioplasty studies of intracranial arterial stenosis, the first being the study SSYLVIA (Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arterie), a multicenter prospective study that evaluated a new stent ( Neurolink, Guidant, Menlo Park, CA, USA) for its safety and feasibility. This stent is designed for the treatment of intracranial atherosclerotic stenosis. The study had a high technical success rate, with stroke rates of 6.6% and 13.1% at 30 d?and 1 year after the procedure, respectively, and no deaths were reported. Another major contribution of the study was the evaluation of the degree of restenosis and other potential factors associated with clinical symptoms and risk, suggesting that risk factors for possible restenosis at 6 months included diabetes mellitus, severe preoperative stenosis, and postoperative residual stenosis greater than 30%. The incidence of intracranial artery restenosis is similar to that of coronary and peripheral vessels, but the majority (61%) of restenosis cases are not clinically symptomatic. However, the disadvantages are self-evident. This was a company-sponsored study, and the majority of cases were stenoses of the primary segment of the vertebral artery, which, according to national data, has a significantly higher restenosis rate than the intracranial artery, so it is not representative of the overall situation. Another randomized controlled study, also funded by the company, is a prospective non-randomized multicenter study of a self-expanding stent to treat cases of severe symptomatic intracranial atherosclerotic stenosis that have failed medical treatment. The purpose of this study is to evaluate the safety of new self-expanding stents designed for the treatment of intracranial atherosclerotic stenosis and the performance of the operating system. Forty-five patients have been enrolled in the study with a 100% technical success rate and long-term prognostic follow-up is still ongoing, but the stent system requires pre-expansion, which increases the risk of manipulation, and is expensive. Recently, a prospective multicenter study (GESICA study) involving a total of 102 patients who underwent angioplasty after only effective vascular risk factor control and failure of antithrombotic therapy was conducted in several French hospitals with a follow-up of 36 months. Of these patients, 27.4% had clinically significant hemodynamic infarcts, and 38.2% had ischemic episodes during a mean follow-up of 23.4 months, including 13.7% of stroke episodes and 24.5% of TIA episodes. For patients with severe hemodynamic stenosis 60.7% had a recurrent stroke or TIA episode in the area of the donor artery. 28 patients received endovascular treatment and the perioperative complication rate was 14.2%. The vascular-related mortality rate was 8.8%. Overall, the rate of stroke episodes within 2 years in the area of the stenotic artery was 38.2%, even with good medical treatment. The stroke rate is even higher in severe hemodynamic stenoses. Angioplasty performed by experienced physicians can be effective in preventing recurrent strokes. Due to the complexity of intracranial arterial stenosis, the pathogenesis of anterior and posterior circulation, clinical regression, and the possible differences in technical complexity, Xuanwu Hospital started a single-center prospective study in June 2003 and has completed 69 young (mean age 42 years, 33-57 years) patients with middle cerebral artery stenosis, all with stenosis greater than 70% and clinical episodes associated with stenotic vessels. Of these, 47 were treated with medical drugs and 22 received angioplasty if medical treatment failed, with a mean follow-up of 27 months. Preliminary results showed that 10.53% of patients in the medical treatment group had a total stroke episode (including TIA stroke or episode), while 2.56% of patients in the angioplasty group had a perioperative complication rate of 3.15% and a restenosis rate of 9.37%. From the preliminary results, it appears that endovascular angioplasty can reduce the rate of stroke recurrence.