Carotid artery stenting: to be or not to be?

Carotid endarterectomy (CEA) has been the standard of care for suitable patients with symptomatic or asymptomatic high grade carotid stenosis since the landmark NASCET (North American Symptomatic Carotid Endarterectomy Trial), ECST (European Carotid Surgery Trial) and ACAS (Asymptomatic Carotid Artery Surgery) studies performed in the 1990s and more recently the ACST (Asymptomatic Carotid Surgery Trial). Carotid artery stenting (CAS) in the treatment of both symptomatic and asymptomatic patients with high grade carotid stenosis has recently been investigated as an alternative to CEA. We present a review of the most recent CAS trials and examine some of the controversies that surround them.     

Recurrent carotid stenosis after CEA and CAS: diagnosis and management

Carotid endarterectomy (CEA) is the preferred method for cerebral revascularization in patients with symptomatic and asymptomatic high-grade extracranial carotid artery stenosis. Carotid artery stenting (CAS) has recently emerged as a less invasive alternative to endarterectomy. Carotid stenting has been demonstrated to be technically feasible and safe in high-risk patients. It has been approved as an acceptable method for revascularization in circumstances where CEA yields suboptimal results. While the final role of CAS in carotid revascularization will be determined on the basis of ongoing randomized trials, it is clear that stenting will continue to be performed in subgroups of patients with carotid stenosis. Therefore, it is anticipated that there will be a corresponding increase in the number of in-stent restenosis cases. Considerable controversy exists regarding the clinical significance, natural history, threshold for management, and appropriate intervention of recurrent carotid stenosis after endarterectomy and after stenting. This review analyzes current information on this important clinical problem and presents evidence-based recommendations for the diagnosis and management of recurrent carotid stenosis.     

Advances in the management of carotid artery disease: focus on recent evidence and guidelines

Recent landmark randomized trials and society guidelines have significantly revised the management of carotid artery disease. Duplex ultrasonography is the recommended initial diagnostic test for the assessment of extracranial carotid artery stenosis. Carotid artery imaging is reasonable in select patients scheduled for coronary artery bypass graft (CABG) surgery. Carotid revascularization can be achieved safely and effectively with carotid endarterectomy or carotid artery stenting. Because each procedure has a different risk/benefit profile, the optimal approach is to match the particular patient to the intervention that maximizes outcome benefit. Carotid revascularization is recommended in patients scheduled for CABG surgery when the carotid artery stenosis is symptomatic and/or bilateral. Further trials are required to guide the management of asymptomatic unilateral carotid artery stenosis in patients undergoing CABG surgery. Aggressive medical therapy remains the gold standard for intracranial carotid artery disease because landmark trials have shown no outcome improvement with vascular bypass or percutaneous angioplasty and stenting. A large recent trial showed that local anesthesia, as compared with general anesthesia, for carotid endarterectomy has no major clinical outcome advantage. Although carotid artery stenting is associated with a reduced risk of myocardial ischemia, it still has important risks of stroke and hemodynamic instability that significantly affect clinical outcome. The timing and choice of carotid revascularization technique ultimately depends on multiple clinical factors.     

Myokardiales Risiko bei Karotisendarteriektomie und Stent

Carotid stenosis is an important cause of ischaemic stroke. Carotid endarterectomy (CEA) reduces the risk of stroke among patients with symptomatic and asymptomatic carotid stenosis. Stent treatment has emerged as an alternative to surgery but is associated with a higher risk of periprocedural stroke. Randomised trials have yielded conflicting results regarding the risk of myocardial infarction (MI) with stenting and CEA. These differences are mostly explained by differences between trials in study populations, as well as assessment and definition of MI. Considering all available randomised trial data, periprocedural MI is more common with CEA than with stent treatment. As with periprocedural stroke, periprocedural MI also leads to a decrease in long-term survival. Thus, MI must be regarded a serious adverse event complicating carotid interventions. Stent treatment therefore represents an alternative to CEA among patients with clear indication for carotid revascularisation who are considered at increased risk for coronary events.     

Rationale and status of randomized controlled clinical trials in carotid artery stenting

Efficacy for carotid artery stenting (CAS) has not been confirmed by randomized clinical trial methodology. Although carotid endarterectomy (CEA) is considered the preferred method for carotid revascularization in the management of patients with asymptomatic and symptomatic extracranial carotid occlusive disease, comparisons between CAS and CEA are now underway. In North America, the CREST (Carotid Revascularization Endarterectomy versus Stent Trial) protocol is now completing credentialing cases as randomization of cases is initiated. In Europe, the CAVATAS (Carotid and Vertebral Artery Transluminal Angioplasty Study) and SPACE (Stent Protected Angioplasty versus Carotid Endarterectomy) trials are recruiting symptomatic patients for randomization between CEA and CAS. It is anticipated that these trials will publish definitive results within the next 1-3 years and help guide the referral of patients for CAS and CEA in the future.     

Early carotid artery stenting after onset neurologic symptoms

Multicenter clinical trials level 1 evidence favors the application of carotid endarterectomy in symptomatic patients, especially the in the elderly cohort. Carotid artery stenting has been proposed as a possible early alternative in selected patients after onset of ipsilateral neurologic symptoms. It is well known that treatment of acute stroke is time-dependent in patients with acute ischemic stroke caused by high-grade stenosis of the internal carotid artery, but intensive medical treatment in conjunction with intervention to improve stroke severity and clinical outcomes has not been established. Two major clinical concerns exist: (1) the risk of hemorrhagic infarction after cerebral revascularization in the acute stage and (2) application of carotid stenting in the acute embolic stage, which may be associated with continued embolic risk after carotid artery stenting compared to carotid endarterectomy, which removes the symptomatic plaque. This review summarizes the indications and results of early carotid artery stenting after onset of neurologic symptoms, considering the new carotid stents and cerebral protection systems available for clinical use and enhanced stenting techniques.     

Management of carotid restenosis

Carotid endarterectomy is the preferred method for cerebral revascularization in patients with symptomatic and asymptomatic high-grade extracranial carotid artery stenosis. Carotid artery stenting has recently emerged as a less invasive alternative to endarterectomy. Carotid stenting has been demonstrated to be technically feasible and safe in high-risk patients with current data indicating clinical equipoise with respect to endarterectomy. It is clear that carotid stenting will continue to be performed at increasing rates after these encouraging outcomes. Therefore, it is anticipated that there will be a corresponding increase in the number of in-stent restenosis cases. Considerable controversy exists regarding the clinical significance, natural history, threshold for management, and appropriate intervention of recurrent carotid stenosis after endarterectomy and after stenting. This review analyses current information on this important clinical problem and presents evidence-based recommendations for the diagnosis and management of recurrent carotid stenosis.     

Carotid artery stenting

Efficacy for carotid artery stenting (CAS) has not been confirmed by randomized clinical trial methodology in conventional risk patients. Although carotid endarterectomy (CEA) is considered the preferred method for carotid revascularization in the management of patients with symptomatic and asymptomatic extracranial carotid occlusive disease, comparisons between CAS and CEA are now underway. In North America, the CREST (Carotid Revascularization Endarterectomy versus Stent Trial) protocol is now completing its lead-in or credentialing phase as randomization of cases is initiated. In Europe, the CAVATAS (Carotid and Vertebral Artery Transluminal Angioplasty Study) and Stent Protected Angioplasty versus Carotid Endarterectomy trials are recruiting symptomatic patients for randomization between CEA and CAS.It is anticipated that these trials will publish definitive results within the next 1 to 3 years, and help guide the referral of patients for CAS and CEA in the future.     

Carotid endarterectomy before and after publication of randomized controlled trials

BACKGROUND: In 1991, the European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) demonstrated that carotid endarterectomy (CEA), in addition to best medical therapy, significantly reduces ipsilateral stroke in patients with high-grade (70 per cent or more) carotid artery stenosis compared with best medical therapy alone. In 1995, the Asymptomatic Carotid Atherosclerosis Study demonstrated that CEA was of benefit in asymptomatic patients with stenosis greater than 60 per cent. The aim of this paper was to examine how the practice and outcome of CEA have changed since publication of these data. METHODS: A prospectively gathered computerized database comprising 634 consecutive CEAs was studied. Two time intervals were analysed: 1975-1991 inclusive (17 years) and 1 January 1992 to 1 May 1998 (6 years 4 months). RESULTS: Since 1991, there has been a fourfold increase in the number of CEAs performed annually for symptomatic disease. CEA is now performed almost exclusively for high-grade (more than 70 per cent) stenosis. There has been a significant reduction in the total peri-operative neurological event rate (12.5 versus 5.9 per cent, P < 0.05), and the 30-day combined major stroke (Rankin grade 3-5) and mortality rate has fallen to 2.0 per cent. The number of patients who have CEA for asymptomatic disease remains small with 16 of 30 being randomized within the Asymptomatic Carotid Surgery Trial. CONCLUSION: Publication of ECST and NASCET data has been associated with a major increase in the number of CEAs performed for symptomatic disease in this unit. Despite a greater proportion of high-risk patients, the results have improved progressively.     

Carotid artery stenting versus carotid endarterectomy: current status

Carotid occlusive disease remains an important cause of ischemic stroke. The results of large, randomized, clinical trials have established the benefit of surgical revascularization in patients with symptomatic or asymptomatic carotid stenosis. The introduction of balloon angioplasty and stenting of the extracranial carotid artery as a potential alternative to surgery has been received with enthusiasm by patients and physicians. Whether or not this enthusiasm is justified fully has yet to be determined. This article reviews established and emerging data from clinical trials evaluating the safety and efficacy of carotid endarterectomy, carotid angioplasty, and stenting.     

Current management of extracranial carotid artery disease

Stroke is the third most common cause of death in the United States. There are approximately 700,000 strokes/year; 80% are ischemic, and 20-30% of ischemic strokes are secondary to carotid disease. Carotid stenosis is traditionally treated by carotid endarterectomy (CEA). Multicenter, randomized, controlled trials have shown that surgery significantly reduces the risk of ipsilateral stroke in patients with severe symptomatic and asymptomatic carotid stenosis. Endovascular techniques for treating carotid stenosis have been developed over recent years. Carotid angioplasty and stenting (CAS) with cerebral protection has become an alternative to CEA for high-surgical-risk patients and the procedure of choice for stenoses inaccessible by surgery. In this review we summarize the existing data regarding the traditional state of management of extracranial carotid artery stenosis and compare these data to a critical analysis of the recent results of CAS.     

In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance

OBJECTIVES: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy in cerebral revascularization. Although early results from several centers have been encouraging, concerns remain regarding long-term durability of carotid artery stenting. We report the incidence, characteristics, and management of in-stent recurrent stenosis after long-term follow-up of carotid artery stenting. METHODS: Carotid artery stenting (n = 122) was performed in 118 patients between September 1996 and March 2003. Indications included recurrent stenosis after previous carotid endarterectomy (66%), primary lesions in patients at high-risk (29%), and previous ipsilateral cervical radiation therapy (5%). Fifty-five percent of patients had asymptomatic stenosis; 45% had symptomatic lesions. Each patient was followed up with serial duplex ultrasound scanning. Selective angiography and repeat intervention were performed when duplex ultrasound scans demonstrated 80% or greater in-stent recurrent stenosis. Data were prospectively recorded, and were statistically analyzed with the Kaplan-Meier method and log-rank test. RESULTS: Carotid artery stenting was performed successfully in all cases, with the WallStent or Acculink carotid stent. Thirty-day stroke and death rate was 3.3%, attributable to retinal infarction (n = 1), hemispheric stroke (n = 1), and death (n = 2). Over follow-up of 1 to 74 months (mean, 18.8 months), 22 patients had in-stent recurrent stenosis (40%-59%, n = 11; 60%-79%, n = 6; > or =80%, n = 5), which occurred within 18 months of carotid artery stenting in 13 patients (60%). None of the patients with in-stent recurrent stenosis exhibited neurologic symptoms. Life table analysis and Kaplan-Meier curves predicted cumulative in-stent recurrent stenosis 80% or greater in 6.4% of patients at 60 months. Three of five in-stent recurrent stenoses occurred within 15 months of carotid artery stenting, and one each occurred at 20 and 47 months, respectively. Repeat angioplasty was performed once in 3 patients and three times in 1 patient, and repeat stenting in 1 patient, without complications. One of these patients demonstrated asymptomatic internal carotid artery occlusion 1 year after repeat intervention. CONCLUSIONS: Carotid artery stenting can be performed with a low incidence of periprocedural complications. The cumulative incidence of clinically significant in-stent recurrent stenosis (> or =80%) over 5 years is low (6.4%). In-stent restenosis was not associated with neurologic symptoms in the 5 patients noted in this cohort. Most instances of in-stent recurrent stenosis occur early after carotid artery stenting, and can be managed successfully with endovascular techniques.     

Clinical need,design, and goals for the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis trial

Prior clinical trials produced evidence-based treatment recommendations for patients with asymptomatic carotid stenosis that may not be appropriate for clinical decision-making today. High-quality patient outcomes data to allow informed decision making regarding the optimal management of high-grade asymptomatic internal carotid artery stenosis is lacking. The results of the Asymptomatic Carotid Atherosclerosis Study were published in 1995 based on a randomized patient enrollment in the 1990s. Outcomes after endarterectomy, stenting, and medical treatment for these patients have all improved in the subsequent 2 decades. Therefore, the time has come to test whether contemporary intensive medical therapy is an acceptable alternative to contemporary endarterectomy or stenting and is the rationale for the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis (CREST-2) trial. This National Institute of Neurological Disorders and Stroke−sponsored prospective, multicenter clinical trial has the investigators, study teams, asymptomatic patients, and robust study design needed to provide these answers. Two randomized clinical trials are planned: carotid revascularization and intensive medical management versus medical management alone in patients with asymptomatic high-grade carotid stenosis randomize in a 1:1 ratio; the other trial will randomize patients in a 1:1 ratio to carotid stenting with embolic protection versus no stenting. ClinicalTrials.gov Identifier: NCT02089217.     

Management of patients with concomitant coronary and carotid vascular disease

Stroke is a major complication of coronary artery bypass graft (CABG) surgery. Carotid stenosis is an important cause of stroke in certain CABG patients. Randomized trials have revealed that carotid endarterectomy (CEA) is clearly indicated in non-CABG patients with symptomatic severe carotid stenosis. CEA is also indicated in patients with symptomatic moderate stenosis and asymptomatic severe stenosis if the predicted incidence of perioperative morbidity and mortality is low. Therapeutic options for patients with concomitant coronary and carotid disease include CABG alone, CABG plus CEA, and CABG plus carotid stenting. In this article we discuss each of these management techniques in detail, and make recommendations regarding the preferred approach in specific patient populations.     

Management of atherosclerotic carotid artery disease: clinical practice guidelines of the Society for Vascular Surgery

The Society for Vascular Surgery (SVS) appointed a committee of experts to formulate evidence-based clinical guidelines for the management of carotid stenosis. In formulating clinical practice recommendations, the committee used systematic reviews to summarize the best available evidence and the GRADE scheme to grade the strength of recommendations (GRADE 1 for strong recommendations; GRADE 2 for weak recommendations) and rate the quality of evidence (high, moderate, low, and very low quality). In symptomatic and asymptomatic patients with low-grade carotid stenosis (<50% in symptomatic and <60% in asymptomatic patients), we recommend optimal medical therapy rather than revascularization (GRADE 1 recommendation, high quality evidence). In symptomatic patients with moderate to severe carotid stenosis (more than 50%), we recommend carotid endarterectomy plus optimal medical therapy (GRADE 1 recommendation, high quality evidence). In symptomatic patients with moderate to severe carotid stenosis (>/=50%) and high perioperative risk, we suggest carotid artery stenting as a potential alternative to carotid endarterectomy (GRADE 2 recommendation, low quality evidence). In asymptomatic patients with moderate to severe carotid stenosis (>/=60%), we recommend carotid endarterectomy plus medical management as long as the perioperative risk is low (GRADE 1 recommendation, high quality evidence). We recommend against carotid artery stenting for asymptomatic patients with moderate to severe (>/=60%) carotid artery stenosis (GRADE 1 recommendation, low quality evidence). A possible exception includes patients with >/=80% carotid artery stenosis and high anatomic risk for carotid endarterectomy.     

Karotisendarteriektomie vs. Karotisstent

Carotid stenosis is responsible for 15–20% of ischemic strokes in the adult population. Carotid endarterectomy is a procedure that has been shown to be superior to medical treatment in the prevention of stroke in patients with symptomatic carotid stenosis >70% stenosis according to NASCET criteria. Now randomised studies and meta-analysis reported short term safety and intermediate term efficacy of carotid endarterectomy vs. carotid artery stenting. The periprocedural risk of stroke was shown to be lower for carotid endarterectomy. In the intermediate term follow up, both treatments are comparable in stroke and death prevention. Restonis of carotid artery is significantly higher in the carotid stenting group. Patients age influences the number of primary outcome events in the carotid stenting group.     

Prosthetic bypass for restenosis after endarterectomy or stenting of the carotid artery

Objective

The objective of this study was to evaluate the results of prosthetic carotid bypass (PCB) with polytetrafluoroethylene (PTFE) grafts as an alternative to carotid endarterectomy (CEA) in treatment of restenosis after CEA or carotid artery stenting (CAS).

Optimal contemporary management of symptomatic and asymptomatic carotid artery stenosis

This commentary addresses the issue of optimal contemporary management of symptomatic and asymptomatic carotid artery stenosis. Based on current data, carotid endarterectomy (CEA) should be performed in the majority of patients with symptomatic carotid artery stenosis. Carotid artery stenting (CAS) should be reserved for a minority of these symptomatic patients, in whom CEA is contraindicated. In asymptomatic patients, all should be placed on best medical treatment (BMT). With the use of one or more of the proposed stroke risk stratification models or some as yet undetermined method, the identification of those asymptomatic individuals may be possible in whom stroke risk is higher than usual with BMT. This asymptomatic subgroup, which may be small and is yet to be determined with certainty, could be offered an invasive carotid procedure (either CAS or CEA).     

Symptomatic carotid stenosis: endarterectomy, stenting, or best medical management?

In the past, management of symptomatic carotid stenosis was uncertain. The results of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) in 1991 demonstrated a significant advantage of Carotid Endarterectomy (CEA) compared to medical management with Aspirin (ASA). Since the publishing of the NASCET results, there have been advances in both the medical management of patients with peripheral arterial disease as well as the introduction and improvement of the technique of minimally invasive carotid angioplasty and stenting. With this progress, the question has to be raised about what is the most appropriate treatment option for patients with symptomatic carotid artery stenosis. A review of the prospective clinical trials regarding the medical, surgical and endovascular management will help to elucidate the optimal therapy for symptomatic carotid stenosis.     

Carotid stenting versus endarterectomy

Carotid artery stenting (CAS) has emerged as an alternative to carotid endarterectomy (CEA) for stroke prevention in patients with carotid atherosclerotic disease. Recently, the results of five multicenter, randomized trials comparing CEA and CAS have been reported. The first trial in high-risk patients confirmed that CAS is not inferior to CEA, following trials in symptomatic average-risk patients which demonstrated a slight superiority of CEA over CAS. Subsequently, the latest large-scale trial in symptomatic and asymptomatic conventional-risk patients demonstrated similar results between CAS and CEA. However, the interpretation of the results of those trials remains controversial. Postapproval study of CAS in Japan has demonstrated acceptable results.