| Background and PurposeStroke is the second or third leading cause of death and the first leading cause of adult disability in all the world. Stenosis of the carotid artery constitutes a major risk factor for ischaemic stroke, especially in patients with symptomatic stenosis (recent transient ischaemic attacks, et al). However, the severity of carotid artery stenosis highly predicts risk of ipsilateral ischemic stroke.The annual risk of ipsilateral stroke doubles from 0.5% for internal carotid artery (ICA) stenosis of b50% to 1% for ICA stenosis of 50%-99%.Large randomized trials have convincingly shown that carotid endarterectomy have greater benefit than medical therapies alone, can significantly reduces the longterm risk of subsequent stroke from severe carotid artery stenosis.. These large, randomized, prospective trials, including the North American Symptomatic Carotid Endarterectomy Trial (NASCET), European Carotid Surgery Trial (ECST), Asymptomatic Carotid Atherosclerotic Study (ACAS), and Asymptomatic Carotid Surgery Trial (ACST). Carotid endarterectomy has been regarded as the gold standard for revascularization of severe carotid artery stenosis, and considered the first one in clinical decision-making. But surgery also have disadvantages, such as:requiring an incision in the neck, performed under general anaesthesia and its complications such as myocardial infarction and pulmonary embolism.Since 1990 year, Angioplasty and carotid artery stenting have been suggested as an alternative to carotid endarterectomy for revascularization of carotid artery stenosis, especially for carotid artery restenosis and in patients with high-surgical risk. Before 2005, there were more than 20 published case-series carotid Angioplasty studies involving a total of more than 24,000 patients,about half of patients were symptomatic carotid artery stenosis(51%), and 30-day stroke or death rates were 2% to 7%. Since embolic protection devices were introduced for use during carotid Angioplasty, stroke and death rate within 30 days in both symptomatic and asymptomatic patients was reduced to 1.8%, rather than 5.5% in patients treated without embolic protection devices. Endovascular treatment is usually performed via a femoral catheter, avoiding an incision in the neck and subsequent cranial and cutaneous nerve damage, and without general anesthesia and its complications.However, endovascular techniques also carries a risk of stroke and local complications. As a consequence, before endovascular treatment can be considered as a genuine alternative to surgery, it must be shown to be as safe and effective as surgery. Between 1998 and 2010,11 randomized studies comparing endovascular treatment of the carotid artery with surgery, there were 10 studies out come or part of the date have published, those studies include The CAVATAS trial, The Leicester trial, The Schneider Wall Stent trial, Kentucky A, Kentucky B, The CREST trial, The EVA 3S study, The Sapphire trial, The SPACE trial, The ICSS trial, The TESCAS-C trial and CREST Trial.This article reviews all randomized trials comparing endovascular treatment of the carotid artery with surgery by a meta-analysis,To evaluate the safety and efficacy of endovascular techniques.Materials and MethodsSearch StrategyBibliographic databases selection①MEDLINE (http://isiknowledge.com/medline);②Elsevier Science (http://www.sciencedirect.com/);③PubMed (http://www.ncbi.nlm.nih.gov/pubmed/)④The Excerpta Medica Database, EMBASE;⑤China National Knowledge Infrastructure, CNKI.Search termsSearch terms included "carotid", "stenosis", "endarterectomy", "endovascular", "angioplasty", and "stenting", in various combinations.Study selectionThe search was limited to articles published date to 2010.01.01;randomized trials of carotid endovascular treatment compared with carotid endarterectomy;patients of any age or sex;symptomaticor asymptomatic carotid arterystenosis.Data extractionThe outcome events extracted from each study included, if available:any stroke (disabling or nondisabling) or death, cranial neuro damage, myocardial infarction within 30 days of procedure and any stroke or death within 1 year of procedure.Strokes were classified if possible as fatal, disabling (requiring help with activities of daily living for>1 month after onset) or nondisabling (symptoms lasted>7 days but patient was independent at 30 days).Meta analysisResults were reported as percentages as well as odds ratios (ORs). ORs were calculated using the Peto fixed-effect method or (and) free-sffect method. Heterogeneity between trial results was tested for using a standardχ2 test.ResultsThere are 10 trials, including 4872patients, Symptomatic carotid stenosis 4533 patients (93% in all). Meta-analysis using both random-effect model and fixed-effect model compared outcome events of death, stroke, myocardial infarction, cranial nerve injury at 30 days,6 months, or 1 year after procedure. By fixed-effect modle there were significantly lowwer 30-day event rates after CAS than CEA for stroke [1.29(1.02,1.64), heterogeneity(P=0.001)], and death or any stroke[1.25(1.00,1.57), heterogeneity(P=0.002)].But by random-effects model, there was no significant difference of event rates between treatments for stroke (odds ratio for CAS [95% confidence interval],1.21 [0.69,2.10]), death or any stroke (1.12 [0.68,1.86]), or death,disabilting stroke(1.03 [0.66,1.61]), or death and any stroke at long-term after procedural (1.11 [0.73,1.69]). But also there were significantly lowwer 30-day event rates after CAS than CEA for myocardial infarction [fixed-effect modle 0.45 (0.21,0.98), heterogeneity (p=0.55)], Cranial nerve injury [fixed-effect modle 0.08 (0.03,0.20), heterogeneity (p=0.78)] by fixed-effect model.ConclusionIn the present meta-analysis, there was no significant difference of safety and benefit between patients treated with CAS and CEA.The analyzed trial number was too small to show significant different. The ongoing trials CREST is expected to provide additional clear evidence to make sure which treatment is Golden standard..
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