SummaryBackgroundStents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy.MethodsThe International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470.FindingsThe trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4·0%) events of disabling stroke or death in the stenting group compared with 27 (3·2%) events in the endarterectomy group (hazard ratio [HR] 1·28, 95% CI 0·77–2·11). The incidence of stroke, death, or procedural myocardial infarction was 8·5% in the stenting group compared with 5·2% in the endarterectomy group (72 vs 44 events; HR 1·69, 1·16–2·45, p=0·006). Risks of any stroke (65 vs 35 events; HR 1·92, 1·27–2·89) and all-cause death (19 vs seven events; HR 2·76, 1·16–6·56) were higher in the stenting group than in the endarterectomy group. Three procedural myocardial infarctions were recorded in the stenting group, all of which were fatal, compared with four, all non-fatal, in the endarterectomy group. There was one event of cranial nerve palsy in the stenting group compared with 45 in the endarterectomy group. There were also fewer haematomas of any severity in the stenting group than in the endarterectomy group (31 vs 50 events; p=0·0197).InterpretationCompletion of long-term follow-up is needed to establish the efficacy of carotid artery stenting compared with endarterectomy. In the meantime, carotid endarterectomy should remain the treatment of choice for patients suitable for surgery.FundingMedical Research Council, the Stroke Association, Sanofi-Synthélabo, European Union.

To evaluate ultrasonographically determined intima-media thickness as a measure of early atherosclerosis, three studies were performed. Ultrasound measurements of intimamedia thickness in the carotid artery were directly validated by comparing the same thickness measured by light microscopy. The values were closely correlated (r=.82, P<.001). Intima-media thickness determined by light microscopy was consistently smaller than that determined by ultrasound, probably due to shrinkage during histological preparation. As an indirect validation, mean intima-media thickness was calculated in three large groups of patients with no plaque (n=224), one plaque (n= 105), and one circumferential or two or more plaques (n=54) in the carotid bifurcation. Intima-media thickness increased significantly with increasing plaque score, indicating that diffuse intimamedia thickening is more pronounced with more severe atherosclerosis. The intima-media thickness also increased with increasing multifactorial cardiovascular risk, reflecting a positive relation between signs of early atherosclerosis and the burden of known risk factors for the disease. Our studies support earlier findings that have found that ultrasonographically determined intima-media thickness is a valid way to study early atherosclerosis. (Arterioscler Thromb. 1994;14:261-264.)

Background Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence.Methods ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362.

A noninvasive method based on high-resolution B-mode ultrasonography and a computerized image-analyzing system were used for the quantification of early (thickening of the intimamedia complex) and late (plaque) atherosclerosis in the carotid and the femoral artery. The difference between repeated measurements was assessed to estimate intraobserver and interobserver differences. The results were satisfactory, with a coefficient of variation for measurement of lumen diameter in the common carotid artery of 3.8±4.1% (r=0.91) and for the femoral artery of 4.8±4.1% (r=0.93). Corresponding figures for intima-media thickness in the common carotid artery and the femoral artery were 10.0±8.5% (r=0.86) and 16.2+12.6% (r=0.91), respectively. The coefficient of variation for measurements of maximal intima-media thickness at the site of the plaque was 14.6±10.5% (r=0.88); for plaque base, 13.1 ±9.0% (r=0.91); and for plaque area, 16J± 12.6% (r=0.90). The method seems promising for the detection and quantification of early and late atherosclerotic lesions in the carotid and femoral arteries. (Arteriosclerosis and Thrombosis 1992;12:261-266) I t has been possible to study the extent of atherosclerosis mainly by identifying clinical symptoms or by analyzing morbidity and mortality caused by vascular events. Symptoms and vascular events are, however, signs of advanced vascular disease and, as such, are not useful for studies of the asymptomatic phase of atherosclerosis.In the clinical situation, the extent of atherosclerosis has been evaluated by angiography, but for ethical reasons, this method cannot be used for serial investigations of atherosclerotic lesions in an asymptomatic population. Furthermore, results from other studies suggest that so long as the atherosclerotic process occupies less than 40% of the cross-sectional area inside the internal elastic layer, the artery may dilate to keep its lumen diameter intact, at least in the coronary arteries. Received December 20,1990; revision accepted October 23,1991. diminishes the usefulness of angiography for detection of early atherosclerotic lesions, as this method only visualizes the lumen of the vessel. During the past few years, several groups have attempted to develop noninvasive (ultrasonographic) methods to measure the thickness of the arterial wall.3 -7 Duplex-scanning estimations of the degree of stenosis have been correlated to those on angiograms and to findings in specimens obtained at thrombendarterectomy.8 Studies of intima-media thickness, as determined by high-resolution B-mode ultrasonography and light microscopy, have been done on autopsy material 3 and in animal models, 7 and these show good correlation. The usefulness of this method is substantiated by findings that show that patients with hypercholesterolemia have a thicker intima-media layer than do those with normal serum cholesterol levels. 9 The change in intima-media thickness has also been found to be associated with other risk factors for atherosclerosis.10 Reproducibility concerning the method...

The Delphi methodology allowed for international consensus on a new procedure specific global rating scale for assessment of competence in EVAR. The resulting scale, EndoVascular Aortic Repair Assessment of Technical Expertise (EVARATE), represents key elements in the procedure. EVARATE constitutes an assessment tool for providing structured feedback to endovascular operators in training.