***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND AND PURPOSE Percutaneous transluminal angioplasty ( PTA ) is currently being assessed for the treatment of carotid stenosis . In comparison with carotid endarterectomy ( CEA ) , there is evidence of an increased risk of cerebral microembolism during the procedure . We have sought evidence of any neuropsychological sequelae of carotid PTA and compared it with CEA to demonstrate the relative safety of the 2 treatment options . METHODS The neuropsychological outcomes after CEA and PTA were compared in 2 matched groups of patients with severe symptomatic carotid stenosis , 96 % of whom had been r and omized in the Carotid and Vertebral Artery Transluminal Angioplasty Study ( CAVATAS ) , at a single center .  Transcranial Doppler insonation of the middle cerebral artery was used to measure cerebral reactivity in response to carbon dioxide inhalation before treatment and then to detect microembolization of the ipsilateral cerebral hemisphere and measure changes in blood flow velocity during the procedures . The performance on a neuropsychological test battery administered before , 6 weeks after , and 6 months after the procedure was compared in 20 patients undergoing PTA and 26 having CEA .  RESULTS At 6 weeks , 5 patients in each group showed a similar decline in neuropsychological performance ; global measures showed no significant difference between the 2 procedures , despite a significantly higher incidence of microemboli during PTA . Both groups showed a marked reduction in anxiety after treatment . CONCLUSIONS The findings provide some reassurance that PTA is not associated with greater cerebral complications than CEA , despite the higher embolic load recorded by transcranial Doppler ultrasonography during angioplasty BACKGROUND AND PURPOSE This study reports the surgical results in those patients who underwent carotid endarterectomy in the North American Symptomatic Carotid Endarterectomy Trial ( NASCET ) . METHODS The rates of perioperative stroke and death at 30 days and the final assessment of stroke severity at 90 days were calculated . Regression modeling was used to identify variables that increased or decreased perioperative risk . Non outcome surgical complications were summarized . The durability of carotid endarterectomy was examined . RESULTS In 1415 patients there were 92 perioperative outcome events , for an overall rate of 6.5 % . At 30 days the results were as follows : death , 1.1 % ; disabling stroke , 1.8 % ; and nondisabling stroke , 3.7 % . At 90 days , because of improvement in the neurological status of patients judged to have been disabled at 30 days , the results were as follows : death , 1.1 % ; disabling stroke , 0.9 % ; and nondisabling stroke , 4.5 % . Thirty events occurred intraoperatively ; 62 were delayed . Most strokes result ed from thromboembolism . Five baseline variables were predictive of increased surgical risk : hemispheric versus retinal transient ischemic attack as the qualifying event , left-sided procedure , contralateral carotid occlusion , ipsilateral ischemic lesion on CT scan , and irregular or ulcerated ipsilateral plaque . History of coronary artery disease with prior cardiac procedure was associated with reduced risk . The risk of perioperative wound complications was 9.3 % , and that of cranial nerve injuries was 8.6 % ; most were of mild severity . At 8 years , the risk of disabling ipsilateral stroke was 5.7 % , and that of any ipsilateral stroke was 17.1 % . CONCLUSIONS The overall rate of perioperative stroke and death was 6.5 % , but the rate of permanently disabling stroke and death was only 2.0 % . Other surgical complications were rarely clinical ly important . Carotid endarterectomy is a durable procedure BACKGROUND Percutaneous transluminal angioplasty and stenting ( endovascular treatment ) can be used to treat carotid stenosis , but risks and benefits are uncertain . We therefore compared endovascular treatment with conventional carotid surgery . METHODS In a multicentre clinical trial , we r and omly assigned 504 patients with carotid stenosis to endovascular treatment ( n=251 ) or carotid endarterectomy ( n=253 ) . For endovascular patients treated successfully , we used stents in 55 ( 26 % ) and balloon angioplasty alone in 158 ( 74 % ) . An independent neurologist followed up patients . Analysis was by intention to treat . FINDINGS The rates of major outcome events within 30 days of first treatment did not differ significantly between endovascular treatment and surgery ( 6.4 % vs 5.9 % , respectively , for disabling stroke or death ; 10.0 % vs 9.9 % for any stroke lasting more than 7 days , or death ) . Cranial neuropathy was reported in 22 ( 8.7 % ) surgery patients , but not after endovascular treatment ( p<0.0001 ) . Major groin or neck haematoma occurred less often after endovascular treatment than after surgery ( three [ 1.2 % ] vs 17 [ 6.7 % ] , p<0.0015 ) . At 1 year after treatment , severe ( 70 - 99 % ) ipsilateral carotid stenosis was more usual after endovascular treatment ( 25 [ 14 % ] vs seven [ 4 % ] , p<0.001 ) . However , no substantial difference in the rate of ipsilateral stroke was noted with survival analysis up to 3 years after r and omisation ( adjusted hazard ratio=1.04 , 95 % CI 0.63 - 1.70 , p=0.9 ) . INTERPRETATION Endovascular treatment had similar major risks and effectiveness at prevention of stroke during 3 years compared with carotid surgery , but with wide CIs . Endovascular treatment had the advantage of avoiding minor complications PURPOSE To develop an ex vivo human carotid artery stenting model  that can be used for the quantitative analysis of risk for embolization associated with balloon angioplasty and stenting and to correlate this risk with lesion characteristics to define lesions suitable for balloon angioplasty and stenting . METHODS Specimens of carotid plaque ( n = 24 ) were obtained circumferentially intact from patients undergoing st and ard carotid endarterectomy . Carotid lesions were prospect ively characterized on the basis of angiographic and duplex findings before endarterectomy and clinical findings . Specimens were encased in a polytetrafluoroethylene wrap and mounted in a flow chamber that allowed access for endovascular procedures and observations . Balloon angioplasty and stenting were performed under fluoroscopic guidance with either a Palmaz stent or a Wallstent endoprosthesis . Ex vivo angiograms were obtained before and after intervention . Effluent from each specimen was filtered for released embolic particles , which were microscopically examined , counted , and correlated with various plaque characteristics by means of multivariate analysis . RESULTS Balloon angioplasty and stenting produced embolic particles that consisted of atherosclerotic debris , organized thrombus , and calcified material . The number of embolic particles detected after balloon angioplasty and stenting was not related to preoperative symptoms , sex , plaque ulceration or calcification , or artery size . However , echolucent plaques generated a higher number of particles compared with echogenic plaques ( p < 0.01 ) . In addition , increased lesion stenosis also significantly correlated with the total number of particles produced by balloon angioplasty and stenting ( r = 0.55 ) . Multivariate analysis revealed that these two characteristics were independent risk factors . CONCLUSIONS Echolucent plaques and plaques with stenosis > or = 90 % produced a higher number of embolic particles and therefore may be less suitable for balloon angioplasty and stenting . This ex vivo model can be used to identify high-risk lesions for balloon angioplasty and stenting and can aid in the evaluation of new devices being considered for carotid balloon angioplasty and stenting The Stent-Supported Percutaneous Angioplasty of the Carotid Artery versus Endarterectomy ( SPACE ) Trial is investigating if both treatment modalities are equivalent in the treatment of severe symptomatic carotid stenoses . Patients with symptomatic ( transient ischaemic attack or minor stroke ) stenosis ( above 50 % following the North American Symptomatic Endarterectomy Trial criteria ) eligible for both methods can be recruited into this trial . The primary endpoint is the incidence of an ipsilateral stroke or death between r and omisation and day 30 after treatment . Surgeons as well as the interventionalists have to demonstrate their expertise prior to participation in the trial . Funding is mostly by public institutions ( Federal Ministry of Education and Research and German Research Foundation ) . An external monitoring is applied . Thirty-two centres are currently taking part in the SPACE Trial that has been running in Germany , Austria and Switzerl and for 3 years , and they have been able to recruit a total of around 670 patients . The definitive results of this study can not be expected before 3–5 years BACKGROUND AND PURPOSE There has been concern about carotid percutaneous transluminal angioplasty ( PTA ) carrying a greater risk of cerebral ischemia than carotid endarterectomy . We set out to compare cerebral hemodynamics and microembolization during carotid PTA and CEA . METHODS We used transcranial Doppler to monitor the middle cerebral artery of 28 patients undergoing carotid PTA ( n = 14 ) or carotid endarterectomy ( CEA ) with a shunt ( n = 14 ) . Each period during which the internal carotid artery was occluded by PTA balloon or by clamp when the shunt was not in place was timed . Individual periods were summated to give a total occlusion time . Ischemic time was defined as the period for which mean middle cerebral artery velocity fell to a third or less of baseline . Microembolic signals were counted during each procedure . RESULTS CEA result ed in significantly longer individual and total occlusion time than PTA ( mean individual occlusion time , seconds ) , CEA , 168 + /- 51 ; PTA , 20 + /- 7 ; P < .001 ; mean total occlusion time ; CEA , 337 + /- 70 ; PTA , 26 + /- 10 ; P < .001 . Ischemic time was also significantly longer during CEA than during PTA ( CEA , 165 + /- 40 ; PTA , 17 + /- 5 ; P = .001 ) . There were significantly more microembolic signals during PTA than during CEA ( mean number of microembolic signals during CEA , 52 + /- 64 ; during PTA , 202 + /- 119 ; P = .001 ) . There was no correlation between any of the parameters measured and periprocedural stroke , which occurred in one patient in each group . CONCLUSION PTA results in less hemodynamic ischemia but more cerebral microembolism than  CEA .  In this small series , however , it is not possible to comment on the relations between ischemic time , microembolism , and stroke BACKGROUND Carotid angioplasty ( CA ) has been suggested to be a safer and more cost-effective alternative to carotid endarterectomy ( CEA ) in the management of symptomatic severe internal carotid artery ( ICA ) disease . METHODS The study was conducted as a prospect i ve consecutive r and omized trial of CEA versus CA for symptomatic severe ICA disease in a university teaching hospital . All patients were assessed before and after surgery by a neurologist . The study consisted of 23 patients with focal carotid territory symptoms and severe ICA stenosis ( > 70 % ) who were r and omized to either CEA or CA .  However , only 17 had received their allocated treatment before trial suspension . CEA with patching or CA with stenting were used as interventions . The main outcome measures were death or disabling or nondisabling stroke within 30 days . RESULTS All 10 CEA operations proceeded without complication , but 5 of the 7 patients who underwent CA had a stroke ( P=.0034 ) , 3 of which were disabling at 30 days . CONCLUSIONS After referral , the Data Monitoring Committee invoked the stopping rule and the trial was suspended . The investigators and the Ethics Committee subsequently concluded that the trial could not be restarted -- even in an amended format-primarily because of problems with informed consent . We review many of the ethical dilemmas encountered in the performance of this study . If future trials do suggest a selected role for CA , it is essential that both the inclusion and the exclusion criteria are fully documented BACKGROUND Coronary-stent placement is a new technique in which a balloon-exp and able , stainless-steel , slotted tube is implanted at the site of a coronary stenosis . The purpose of this study was to compare the effects of stent placement and st and ard balloon angioplasty on angiographically detected restenosis and clinical outcomes . METHODS We r and omly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to st and ard balloon angioplasty . Coronary angiography was performed at base line , immediately after the procedure , and six months later . RESULTS The patients who underwent stenting had a higher rate of procedural success than those who underwent st and ard balloon angioplasty ( 9 
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There was no difference either in the rate of stroke during follow-up , but the confidence intervals were very wide and severe ipsilateral carotid stenosis was more frequent 1 year after endovascular treatment than after carotid surgery .
However , there is little convincing evidence that these new devices reduce the rate of stroke .
Moreover , a systematic review of the existing r and omised trial data concluded that there the current evidence does not support a shift away from recommending carotid endarterectomy as the st and ard treatment for carotid stenosis .