Carotid Endarterectomy: Current Concepts and Practice Patterns

Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon.     

Comparative Review of the Treatment Methodologies of Carotid Stenosis

The treatment of carotid stenosis entails three methodologies, namely, medical management, carotid angioplasty and stenting (CAS), as well as carotid endarterectomy (CEA). The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) have shown that symptomatic carotid stenosis greater than 70% is best treated with CEA. In asymptomatic patients with carotid stenosis greater than 60%, CEA was more beneficial than treatment with aspirin alone according to the Asymptomatic Carotid Atherosclerosis (ACAS) and Asymptomatic Carotid Stenosis Trial (ACST) trials. When CAS is compared with CEA, the CREST resulted in similar rates of ipsilateral stroke and death rates regardless of symptoms. However, CAS not only increased adverse effects in women, it also amplified stroke rates and death in elderly patients compared with CEA. CAS can maximize its utility in treating focal restenosis after CEA and patients with overwhelming cardiac risk or prior neck irradiation. When performing CEA, using a patch was equated to a more durable result than primary closure, whereas eversion technique is a new methodology deserving a spotlight. Comparing the three major treatment strategies of carotid stenosis has intrinsic drawbacks, as most trials are outdated and they vary in their premises, definitions, and study designs. With the newly codified best medical management including antiplatelet therapies with aspirin and clopidogrel, statin, antihypertensive agents, strict diabetes control, smoking cessation, and life style change, the current trials may demonstrate that asymptomatic carotid stenosis is best treated with best medical therapy. The ongoing trials will illuminate and reshape the treatment paradigm for symptomatic and asymptomatic carotid stenosis.     

Carotid Artery Stenting

Carotid artery stenting (CAS) has achieved clinical equipoise with carotid endarterectomy (CEA), as evidenced by 2 large U.S. randomized clinical trials, multiple pivotal registry trials, and 2 multispecialty guideline documents endorsed by 14 professional societies. The largest randomized trial conducted in patients at average surgical risk of CEA, CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial) found no difference between CAS and CEA for the combined endpoint of stroke, death, and myocardial infarction (MI) after 4 years of follow-up. The largest randomized trial comparing CAS and CEA in patients at increased surgical risk, SAPPHIRE (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy), looked at 1-year stroke, death, and MI incidence and found no difference in symptomatic patients, but a significantly better outcome in asymptomatic patients for CAS (9.9% vs. 21.5%; p = 0.02). Given that >70% of carotid revascularization procedures are performed in asymptomatic patients for primary prevention of stroke, it is incumbent upon clinicians to demonstrate that revascularization has an incremental benefit over highly effective modern medical therapy alone.     

Carotid artery surgery vs. stent: a cardiovascular perspective.

Stroke is a major health catastrophe that is responsible for the third most common cause of death and the leading cause of disability. Carotid artery stenosis is an important cause of brain infarctions and the risk of stroke is directly related to the severity of carotid artery stenosis and to the presence of symptoms. Familiarity with different methods of measuring degrees of carotid artery stenosis is a key in understanding the role of revascularization of this disorder. Carotid endarterectomy (CEA), surgical removal of the carotid atherosclerotic plaque, is intended to prevent stroke in patients with carotid artery stenosis and currently the most commonly performed vascular procedure in the United States. Several randomized clinical trials had demonstrated the benefits of CEA in selected groups of patients with symptomatic and asymptomatic carotid artery stenosis. However, CEA can cause stroke, the very thing it intended to prevent, and is associated with significant perioperative complications such as those related to general anesthesia, cardiac or nerve injury. Moreover, several anatomical and medical conditions may limit candidates for CEA. Carotid artery stenting (CS) is an evolving and less invasive technique for carotid artery revascularization. Recent studies demonstrated that CS with embolic protection devices has become an alternative to CEA for high-surgical-risk patients and the procedure of choice for stenoses inaccessible by surgery. The role of CS in low risk patients awaits the completion of several ongoing studies.     

Treatment strategies for carotid stenosis in patients at increased risk for surgery

The purpose of carotid revascularization is stroke prevention. The merits of carotid revascularization as well as the type of revascularization are dependent on the “natural risk” and the “revascularization risk.” In general, the natural risk of stroke in any patient with carotid stenosis (CS) is dependent on the symptomatic status of the patient and CS severity. Contemporary choices for carotid revascularization include carotid endarterectomy (CEA) and carotid artery stenting (CAS). Anatomical (hostile neck situations, severe bilateral CS, CEA restenosis) and clinical (severe cardiopulmonary diseases, prior cranial nerve injury) factors may increase the risk of CEA. Likewise, anatomical (complex aortic arch and brachiocephalic arterial anatomy, presence of thrombus, and heavy calcification) and clinical (need for heart surgery within 30 days) factors may increase the risk of CAS. Other factors such as the presence of symptomatic CS (transient ischemic attack or stroke within 6 months), decreased cerebral reserve, chronic kidney disease, and age older than 75 years may increase the risk of CEA and CAS. In general, symptomatic patients with severe CS exceed revascularization risk. In contrast, asymptomatic patients who are high risk for CEA should be considered for CAS because the natural risk of stroke should undergo careful assessment of baseline cognitive function, aortic arch and carotid artery anatomy, and likelihood of survival for 3 years. Patients who have normal cognitive function, favorable anatomy, and high likelihood of survival more than 3 years should be considered for CAS, whereas patients with multiple unfavorable features may be treated with optimal medical therapy, without revascularization.     

Optimal treatment of carotid artery disease

Extracranial carotid artery disease accounts for approximately 25% of ischemic strokes. Although carotid endarterectomy (CEA) is the established gold standard for carotid revascularization, carotid artery angioplasty and stenting (CAS) is continually developing into a safer and more efficacious method of stroke prevention. Embolic protection, improving stent designs, and ever-increasing surgeon experience are propelling CAS towards equipoise with and possible superiority to CEA. One multicenter randomized trial and several nonrandomized registries have successfully established CAS as an accepted treatment for high-risk patients. Clinicians must strive to perform well-designed clinical trials that will continue to aid understanding and improve application of both endovascular and open techniques for extracranial carotid revascularization. We review the data published to date regarding the indications for and recent developments in the use of CAS.     

Karotisstenose

Carotid stenosis amenable to surgical or interventional revascularization accounts for 5–12% of all new strokes. Duplex sonography, due to its high sensitivity and specificity is the first and most important step in establishing the diagnosis. Several randomised trials have proven the superiority of carotid endarterectomy (CEA) over medical treatment of symptomatic and also asymptomatic stenoses. For a growing number of patients carotid artery stenting (CAS) can be an alternative. The safety of CAS has improved in recent years due to technical developments, especially cerebral protection systems. According to large registries and also randomised trials the complication rate is comparable to CEA, at least for high surgical risk patients. Results of further randomised trials remain awaited before CAS will also be recommended for low risk patients and patients with asymptomatic stenoses.     

The carotid artery revascularization and endarterectomy (CARE) registry: Objectives,design, and implications

This is the first comprehensive national registry that will provide data characterizing contemporary results of carotid endarterectomy (CEA) and carotid artery stenting (CAS). Carotid endarterectomy (CEA) has become the standard revascularization therapy to prevent stroke in patients with carotid artery disease, while carotid artery stenting (CAS) offers a percutaneous alternative in selected patients. Given the rapid growth in the numbers of CAS procedures being performed, there is a critical need for a national program to assess quality outcomes. The Carotid Artery Revascularization and Endarterectomy (CARE) Registry was developed through a multispecialty collaboration resulting in a comprehensive data collection tool for carotid revascularization procedures. The intent of the CARE registry is to collect and analyze clinical data to measure clinical practice, patient outcomes, and enable quality improvement for carotid revascularization. Finally, the CARE Registry satisfies the Center for Medicare and Medicaid Services (CMS) data reporting criteria for reimbursement. © 2008 Wiley‐Liss, Inc.     

颈动脉内膜切除术和支架置入术后再狭窄的诊断和治疗

作为一种经典的血管重建方式,颈动脉内膜切除术(carotid endarterectomy,CEA)已被广泛用于颅外颈动脉重度狭窄的治疗.近年来,颈动脉支架置入术(carotid artery stenting,CAS)已有逐步取代CEA的趋势.大量临床研究发现,除围手术期并发症外,CEA和CAS后颈动脉再狭窄对患者的预后也具有重要影响.文章就CEA和CAS术后再狭窄的诊断和治疗研究现状做了综述.     

Revascularization of carotid artery stenosis - a brief update on current evidence

Major and long-awaited trials comparing carotid endarterectomy (CEA) with carotid stenting (CAS) were published in recent years. Both, ICSS and CREST, documented a higher rate of periprocedural stroke and death in CAS, in particular in elderly patients, thereby confirming the results of prior trials and meta-analyses. In CREST, the composite endpoint included myocardial infarction (MI), which led to statistical equipoise between the treatment arms due to a higher rate of MI with CEA. However, whether MI is a relevant endpoint in trials for stroke prevention remains debatable. The stroke preventive benefit seems equally sustained after CEA and CAS, although the significance of restenoses, whose frequency is twice as high after CAS compared to CEA, is unclear in the long range. Emergent CEA in patients with clinically unstable carotid stenosis is associated with a very high complication risk, but the optimal treatment strategy for these patients remains to be elucidated. Recent evidence indicates a very low stroke risk of asymptomatic stenoses with intensive medical treatment, rendering revascularization almost unnecessary. The detection of microembolic signals on transcranial Doppler and rapid stenosis progression by duplex sonography might help to identify patients with higher stroke risk in whom revascularization is warranted.     

Interventional Management of Asymptomatic Extracranial Carotid Stenosis

Carotid artery stenosis is a major risk factor for stroke and transient ischemic attack. Although carotid endarterectomy is the established gold standard for carotid revascularization, carotid artery angioplasty and stenting (CAS)—proven by large randomized clinical trials and rigorous registries and supported by improving stent designs, embolic protection, and increasing neurointerventionalist experience—is developing into a safer and more efficacious method of stroke prevention. Today, protected CAS is approved for symptomatic and asymptomatic patients with severe carotid stenosis with high surgical risk. We reviewed recently published data regarding new developments in the use of protected CAS, particularly in patients with carotid stenosis who are either asymptomatic or at low surgical risk.     

Guidelines for patient selection and performance of carotid artery stenting

The endovascular treatment of carotid atherosclerosis with carotid artery stenting (CAS) is controversial. The inter-collegiate Carotid Stenting Guidelines Committee (CSGC) recommends that CAS should not be performed in the majority of patients requiring carotid revascularization. CAS may be considered for specific high risk patients with symptomatic severe carotid stenosis who have contraindications for carotid endarterectomy, or in those under 70years of age where carotid re-vascularization is considered appropriate. Advances in endovascular technologies and the long-term results of randomized controlled trials will guide future revisions of these guidelines.     

Neuroprotection during carotid artery stenting using the GORE flow reversal system: 30‐day outcomes in the EMPiRE Clinical Study

Background : Each of the embolic protection devices used in carotid artery stenting (CAS) has advantages and disadvantages. The prospective, multicenter, single‐arm EMPiRE Clinical Study investigated a proximally placed device (GORE Flow Reversal System) that provides distal neuroprotection during CAS by reversing blood flow in the internal carotid artery, thereby directing emboli away from the brain. Methods : The study evaluated 30‐day outcomes in 245 pivotal high‐surgical‐risk patients (mean age, 70 years; 32% symptomatic; 16% ≥80‐years old) with carotid stenosis who underwent CAS using the flow reversal system. The primary endpoint was a major adverse event (MAE; stroke, death, myocardial infarction, or transient ischemic attack) within 30 days of CAS. The MAE rate was compared with an objective performance criterion (OPC) derived from CAS studies that included embolic protection. Results : The MAE rate was 4.5% (11 patients; P = 0.002 compared with the OPC). The stroke and death rate was 2.9%. No patient had a major ischemic stroke. Six patients (2.4%) had intolerance to flow reversal. The death and stroke rates in the symptomatic, asymptomatic, and octogenarian subgroups were 2.6, 3, and 2.6%, respectively, meeting American Heart Association guidelines for carotid endarterectomy. Conclusion : The stroke and death rate in this study was among the lowest in CAS trials. The results indicate that the flow reversal system is safe and effective when used for neuroprotection during CAS and that it provides benefits in a broad patient population. © 2010 Wiley‐Liss, Inc.     

Carotid artery revascularization with distal protection in high‐surgical‐risk patients in routine clinical practice: Rationale and design of the CABANA safety surveillance program

Background: Continuous improvement in carotid artery stenting (CAS) outcomes, especially for periprocedural death and stroke in high‐surgical‐risk patients, have been seen in recent randomized trials of CAS versus carotid endarterectomy and CAS registries. However, these studies use stringent inclusion/exclusion criteria for patient, institution, and physician selection. The Carotid Stenting Boston Scientific Surveillance Program (CABANA) study was initiated to evaluate periprocedural outcomes with modern versions of the Carotid Wallstent and FilterWire EZ System for operators with a wide range of clinical specialties, CAS experience and training levels, in patients with a broad range of high‐surgical‐risk conditions and lesion types. Methods: This prospective, single‐arm study enrolled 1,097 subjects with 1,098 carotid artery lesions at 99 study centers. Investigators were grouped into one of three tiers according to whether they had a high, medium, or low level of previous CAS experience and were also categorized by their CAS‐credential‐based training requirements for the CABANA study. Follow‐up at 30 days includes clinical evaluation and independent neurological and NIH stroke scale assessments. The primary endpoint rate of 30‐day composite stroke, death, and MI, as well as the rates of these individual events, will be evaluated across the overall study, by physician experience tier, and by physician training tier. Discussion: The evaluation of periprocedural CAS safety in a real‐world environment with modern devices in high‐surgical‐risk patients treated by physicians with a broad range of training and experience will better inform treatment decisions in the future. © 2011 Wiley Periodicals, Inc.     

Safety of carotid artery stenting for symptomatic carotid artery disease: a meta-analysis.

AIMS: Clinical trials comparing carotid artery stenting (CAS) with carotid endarterectomy (CEA) for patients with symptomatic carotid artery disease have produced conflicting results. We performed a meta-analysis to systematically evaluate currently available data by comparing CAS with CEA in patients with symptomatic carotid artery disease. METHODS AND RESULTS: We searched MEDLINE, Embase, ISI Web of Knowledge, Current Contents, International Pharmaceutical Abstracts databases, the Cochrane Central Register of Controlled Trials, and scientific meeting abstracts up to 31 October 2006 and then calculated summary risk ratios (RRs) for mortality, stroke, disabling stroke, and death using random- and fixed-effect models. Data from five trials with 2122 patients were pooled. There was no difference in risk of 30-day mortality (summary RR 0.57, 95% CI 0.22-1.47, P = 0.25), stroke (summary RR 1.64, 95% CI 0.67-4.00, P = 0.34), disabling stroke (summary RR 1.67, 95% CI 0.50-5.62, P = 0.50), death and stroke (summary RR 1.54, 95% CI 0.81-2.92, P = 0.19), or death and disabling stroke (summary RR 1.19, 95% CI 0.57-2.51, P = 0.64) among patients randomized to CAS, compared with CEA. CONCLUSIONS: No significant differences could be identified between CAS and CEA in the treatment of patients with symptomatic carotid artery disease. Larger randomized controlled trials are warranted to compare the two strategies.     

颈动脉支架与内膜切除术治疗颈动脉狭窄疗效和安全性的Meta分析

目的 系统评价颈动脉支架(carotid artery stenting,CAS)和颈动脉内膜切除术(carotid endarterectomy,CEA)治疗颈动脉狭窄的安全性和疗效.方法 计算机检索PubMed、EMbase、Cochrane图书馆临床对照试验资料库、中国期刊全文数据库(CNKI)、中文科技期刊数据库(VIP)以及万方医学数据库,并辅以手工检索,收集CAS和CEA治疗颈动脉狭窄的随机对照试验,采用Cochrane协作网提供的RevMan 5.0.24软件进行Meta分析.结果 共纳入12个研究,6903例患者,其中CAS组3460例,CEA组3443例.CAS组术后30 d脑卒中或死亡联合发生风险(RR=1.64,95%CI:1.33～2.03,P＜0.00001)以及脑卒中风险(RR=1.70,95%CI:1.34～2.14,P＜0.00001)高于CEA组;CEA组术后30 d心肌梗死风险(RR=0.62,95%CI:0.39～0.97,P=0.04)和颅神经损伤风险(RR=0.07,95%CI:0.03～0.16,P＜0.00001)高于CAS组;两组术后30 d死亡风险(RR=1.33,95%CI:0.78～2.28,P=0.29)、致残性脑卒中风险(RR=1.27,95%CI:0.82～1.96,P=0.29)和术后1年脑卒中或死亡联合发生风险(RR=0.96,95%CI:0.63～1.46,P=0.84)差异无统计学意义.结论 从安全性方面考虑,对于一般手术风险的颈动脉狭窄患者,CEA仍是治疗颈动脉狭窄的首选治疗手段.具有手术高危因素或不适合手术的患者,CAS治疗更具有优势.

Abstract：

Objective To compare the safety and efficacy of carotid artery stenting (CAS) and carotid endarterectomy(CEA) for the treatment of carotid stenosis. Methods The electronic databases (PubMed, EMbase, Cochrane Central Register of Controlled Trials, CNKI, VIP and Wanfang) were searched in order to retrieve randomized controlled trials (RCTs) about comparing CAS and CEA for the treatment of carotid stenosis. Cochrane collaboration's RevMan 5.0.24 were used for analyzing data. Results Twelve RCTs totalling 6903 patients (3460 patients were randomized to CAS and 3443 randomized to CEA) with symptomatic or asymptomatic stenosis were included in the meta-analysis. There were significantly higher 30-day relative risks after CAS than after CEA for death or any stroke [RR=1.64, 95%CI (1.33-2.03), P＜0.00001] and for stroke [RR=1.70, 95%CI (1.34-2.14), P＜0.00001]. The relative risks of myocardial infarction [RR=0.62, 95%CI (0.39-0.97), P=0.04] and cranial neuropathy [RR=0.07, 95%CI (0.03-0.16), P＜0.00001] was significantly less after CAS than after CEA. The relative risks of death [RR=1.27, 95%CI (0.82-1.96), P=0.29] or disabling stroke within 30 days [RR=1.33, 95%CI (0.78-2.28), P=0.29] and any stroke or death at 1 year after the procedures [RR=0.96, 95%CI (0.63-1.46), P=0.84] did not differ significantly between CAS and CEA operation. Conclusions CEA remains the first choice for treatment of carotid stenosis for patients with low surgery risk. For patients with high surgery risk and unsuitable for surgery, CAS has more advantages. It is reasonable to view CAS and CEA as complementary rather than competing modes of therapy.     

Percutaneous versus surgical revascularization for symptomatic carotid artery disease

Stroke is the third leading cause of death worldwide and the number one disease associated with permanent disability. In 2006, the estimated total cost of stroke in the United States was a staggering $60 billion. Significant stenosis of the internal carotid artery is responsible for 10% to 20% of all strokes, and current recommendations suggest that patients with symptomatic carotid artery stenosis undergo revascularization for stroke prevention or risk reduction. Since the 1950s, carotid endarterectomy (CEA) has been the dominant modality of revascularization. However, carotid artery angioplasty, introduced in the 1980s, and subsequent carotid artery stenting (CAS), have greatly improved in recent years and provide a viable alternative to CEA, particularly for certain high-risk patients. Encouraging results from clinical studies of CAS and CEA have played pivotal roles in shaping current practice guidelines. We review the published studies on CAS and discuss appropriate use of this procedure for symptomatic carotid artery disease.     

Carotid artery stenting: a therapeutic alternative in subtotal internal carotid artery occlusions

Carotid artery stenting (CAS) is emerging as a less invasive modality for treating atherosclerotic occlusive disease of the internal carotid artery (ICA). Randomized trials like the SAPPHIRE trial have demonstrated that CAS is not inferior to carotid endarterectomy (CEA) in the treatment of carotid artery stenosis, and maybe even superior in high-risk symptomatic patients. However, patients with subtotal ICA occlusions with thrombus are excluded from randomized CAS trials and CAS registries. To our knowledge, carotid angioplasty with stenting has not been attempted in these cases. We present three cases of symptomatic subtotal ICA occlusions successfully treated with CAS without any periprocedural complications. With careful patient selection and technical expertise, endovascular management could be considered as a treatment option in subtotal carotid occlusions.     

颈动脉狭窄患者的脑功能储备评价

颈动脉支架置入术（CAS）和颈动脉内膜切除术（QEA）是目前颈动脉狭窄患者最主要的非药物治疗方法。评价颈动脉狭窄患者的脑功能储备,不仅能筛选出近期可能面临卒中的高危患者,而且还能对无症状颈动脉狭窄患者行CEA和CAS的纳入标准进行修正,从而为患者提供最佳的治疗方案。文章对颈动脉狭窄患者的脑功能储备评价和MRI在其中的应用做了综述。     

颈动脉内膜剥脱术治疗老年症状性颈动脉狭窄的研究

目的探讨颈动脉内膜剥脱术(CEA)在老年症状性颈动脉狭窄中的应用。方法回顾分析我院108例老年症状性颈动脉狭窄行CEA患者的临床资料。结果 108例患者行CEA共125例次,成功率100%,其中颈动脉狭窄60%～75%者48例次,占38.4%,狭窄>75%者77例次,占61.6%,围手术期严重并发症2例,发生率1.9%,围手术期死亡1例,占0.9%。101条颈动脉术后1个月经颈多普勒超声显示,颈内动脉最狭窄处血管内径较术前明显增加[(6.11±1.36mmvs 1.59±0.82mm,P<0.05],狭窄程度由术前的(78±21)%降至(14±12)%,最狭窄处收缩期最大流速明显改善[(208±22)cm/s vs(93±18)cm/s,P<0.05]。81例患者术后18个月脑缺血症状较术前改善者75例(92.6%),再发短暂性脑缺血发作5例(6.2%),脑卒中1例(1.2%),发现术侧颈动脉>60%的再狭窄1例(1.2%),低于北美症状性颈动脉剥脱试验水平。结论 CEA是治疗老年症状性颈动脉狭窄的有效方法,在预防老年患者缺血性脑卒中等重大脑血管事件的发生中有重要价值。