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.     

Aktueller Status von ECST-2

Background

Carotid endarterectomy (CEA) is a common procedure performed in patients who have suffered a stroke or transient ischaemic attack (TIA) to prevent a recurrent event. Clinical trials have provided evidence for the safety and efficacy of CEA in patients with recently symptomatic stenosis. Carotid artery stenting is an alternative to CEA. However, medical treatment has improved in the last 30 years and trials are ongoing to assess the use of modern medical treatment in selected patients with carotid disease as an alternative to revascularization.

Methods

We have reviewed the published results from clinical trials investigating the best treatment for symptomatic and asymptomatic carotid artery stenosis. In this review we discuss carotid endarterectomy, stenting and medical treatment. We have also included an update on the Second European Carotid Surgery Trial (ECST-2) which is an ongoing trial comparing revascularization to optimized medical therapy in patients with low to intermediate risk of recurrent stroke.

Results

The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) both show that patients with high-risk symptomatic carotid stenosis benefit from CEA over medical treatment alone. However, it has been shown that surgery appeared to be harmful or at least not beneficial in patients included in the trials whose characteristics predicted a low risk of recurrent stroke. The Asymptomatic Carotid Surgery Trial (ACST) also showed a small benefit in treating asymptomatic patients with CEA over medical therapy. Several published trials have compared stenting with endarterectomy and although endarterectomy appears safer in the short term, both treatments have similar long-term outcomes; therefore stenting can be used as an alternative to CEA for selected patients.

Conclusion

CEA and stenting can both be offered to patients with recently symptomatic carotid stenosis to prevent recurrent stroke. We await the results of current trials investigating the role of modern medical therapy in selected patients with low to intermediate risk of recurrent stroke as an alternative to revascularization. The English full-text version of this article is available at SpringerLink (under “Supplemental”).     

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.     

Carotid Endarterectomy for Symptomatic,but “Haemodynamically Insignificant” Carotid Stenosis

ObjectiveCarotid endarterectomy (CEA) guidelines in symptomatic carotid stenosis are based on NASCET and ECST criteria with 70% or greater carotid stenosis as estimated from a catheter angiogram the major indication. This has several problems: (1) lack of reliable correlation between non-invasive imaging and catheter angiography, which has been largely superseded by non-invasive imaging in investigating carotid stenosis; (2) errors inherent in estimating the degree of stenosis from catheter angiography; (3) disregard for the fact that stroke risk also depends on plaque stability, and number of ischaemic events.MethodsA retrospective review of ischaemic events, imaging results, operative findings, surgical complications and stroke-free follow-up in 31 patients presenting over a 23 year period with TIA/stroke (symptoms lasting > 24 h and/or imaging evidence of infarction) who had 70% or less carotid stenosis (on non-invasive imaging), but nonetheless underwent CEA.ResultsNineteen patients had small strokes, 7 had TIAs and 5 had ocular events; 28 patients had features of unstable plaque on imaging; 19 patients experienced multiple events before CEA. All had haemorrhagic, ruptured plaque at CEA. One patient suffered an intra-operative stroke, only 1 patient suffered a further stroke/TIA (mean follow-up 4.2 years).ConclusionTo predict the likelihood of major stroke in symptomatic carotid stenosis and the benefit of CEA, plaque stability and the number of ischaemic events might be as important as an estimate of the degree of stenosis.     

Audit of 149 consecutive carotid endarterectomies performed by a single surgeon in a district general hospital over a 12-year period.

Carotid endarterectomy has been established by two large randomised controlled trials (European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET)) as an important surgical procedure for the prevention of ischaemic strokes in patients presenting with transient cerebral ischaemia or non-disabling strokes attributable to severe ipsilateral carotid artery stenosis. The operation carries significant risk of death and stroke and it has been advocated by some that carotid endarterectomy should only be performed in a small number of designated regional centres in order to achieve good surgical results. It is doubtful that the regional centres alone can cope with the increasing numbers of patients requiring carotid endarterectomy and there is therefore a requirement for the procedure to be carried out by vascular surgeons in district general hospitals. It is important that surgical results are audited to ensure that comparable outcomes are achieved. We present an audit of our experience of carotid endarterectomy since 1981. A total of 149 consecutive carotid endarterectomies were performed by a single surgeon with a special interest in carotid surgery. The results are comparable to ECST with a 30-day mortality of 0% and an overall 30-day stroke rate of 5.7% (major strokes) for patients with severe, ie 70-99%, ipsilateral carotid artery stenoses. We have shown that carotid endarterectomy is an operation that can be performed safely and with good results by suitably trained surgeons in district general hospitals.     

Comparison of color-flow Doppler scanning, power Doppler scanning, and frequency shift for assessment of carotid artery stenosis

OBJECTIVE: We investigated the accuracy of color-flow Doppler (CD) scanning, power Doppler (PD) scanning, and peak systolic Doppler frequency shift (PSF) in assessment of carotid artery stenosis with angiography used as gold standard, including the measurement techniques used in the North American Symptomatic Carotid Surgery Trial (NASCET) and the European Carotid Surgery Trial (ECST). METHODS: Fifty-eight consecutive patients diagnosed for carotid artery surgery underwent color-coded duplex sonography and angiography. The duplex examination included the assessment of PSF and the videotaping of sagittal images in CD and PD mode from the proximal common carotid artery to the distal internal carotid artery. Two experienced examiners performed the studies, but once one examiner had done the taping, the other examiner was allowed only to review the tape. Separately, each examiner reviewed the tapes and determined by cursor settings each stenosis according to NASCET and ECST. For interobserver agreement kappa statistic was used. To compare with angiography (degree of stenosis 40%, 50%, 60%, 70%, and 80%) sensitivity, specificity, positive and negative predictive values, and overall accuracy were calculated. PSF cut-off frequencies were based on receiver operator curve analysis. RESULTS: Because interobserver agreement in CD and PD was good (chance-corrected kappa > 0.6), further analysis used the between-observer mean value for each stenosis. With the NASCET measurement technique, accuracy of Doppler techniques to distinguish a 50% stenosis was 89% for PSF, 91% for CD, and 93% for PD; for a 70% stenosis it was 83% for PSF, 84% for CD, and 81% for PD. With the ECST measurement technique, accuracy to distinguish a 70% stenosis was 86% for PSF, 88% for CD, and 86% for PD; for an 80% stenosis it was 87% for PSF, 87% for CD, and 77% for PD. CONCLUSION: CD and PD carotid artery stenosis measurements are highly reproducible, and in our hands provided accuracy equal to PSF.     

Influence of NASCET/ACAS trial eligibility on outcome after carotid endarterectomy.

PURPOSE: Proponents of carotid angioplasty and stenting suggest that "high risk" patients, defined as patients excluded from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and Asymptomatic Carotid Atherosclerosis Study (ACAS), may have a significantly higher risk of stroke with carotid endarterectomy (CEA). However, this selected patient cohort has been poorly studied. METHODS: A retrospective review of patients who underwent CEA during a 2-year period at a tertiary referral institution was performed. Each patient was evaluated and categorized, according to the exclusion criteria, by NASCET and ACAS standards. Statistical analysis using chi(2) and Fisher exact tests was performed. RESULTS: There were 366 CEAs performed on 348 patients, including 32 (8.7%) for recurrent stenosis. A subgroup of 169 (46.2%) patients were trial ineligible. Focal ipsilateral symptoms were present in 148 (40.4%) of the patients. There were 9 (2.5%) strokes and 1 (0.3%) death, secondary to a major stroke, for an overall stroke and death rate of 2.5%. Trial-eligible patients had a stroke/death rate of 1.5% (3/197) while trial-ineligible patients had a 3.6% (6/169) stroke/death rate (P = .17). CONCLUSION: Patients who were considered high risk for CEA as defined by trial ineligibility were common, comprising approximately half of our patients. Although trial-ineligible patients had a nonsignificant trend toward higher neurologic morbidity when compared with the eligible group, the risks were still comparable with NASCET/ACAS results. CEA was a safe procedure even in this "high risk" group. As such, ineligibility for a randomized carotid intervention trial should not be employed as a "de novo" indication for carotid stenting.     

Effect of image normalization on carotid plaque classification and the risk of ipsilateral hemispheric ischemic events: results from the asymptomatic carotid stenosis and risk of stroke study

The aim of this study was to determine the effect of image normalization on plaque classification and the risk of ipsilateral ischemic neurologic events in patients with asymptomatic carotid stenosis. The first 1,115 patients recruited to the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study with a follow-up of 6 to 84 months (mean 37.1 months) were included in this study. Duplex ultrasonography was used for grading the degree of internal carotid artery stenosis and for plaque characterization (types 1-5), which was performed before and after image normalization. One hundred sixteen ipsilateral ischemic hemispheric events occurred. Image normalization resulted in 60% of plaques being reclassified. Before image normalization, a high event rate was associated with all types of plaque. After image normalization, 109 (94%) of the events occurred in patients with plaque types 1 to 3. For patients with European Carotid Stenosis Trial (ECST) 70 to 99% diameter stenosis (equivalent to North American Symptomatic Carotid Endarterectomy Trial [NASCET] 50-99%) with plaque types 1 to 3, the cumulative stroke rate was 14% at 7 years (2% per year), and for patients with plaque types 4 and 5, the cumulative stroke rate was 0.9% at 7 years (0.14% per year). The results suggest that asymptomatic patients with plaque types 4 and 5 classified as such after image normalization are at low risk irrespective of the degree of stenosis.     

Ultrasound based measurement of 'carotid stenosis >70%': an audit of UK practice.

OBJECTIVES: To determine velocity thresholds for diagnosing 'carotid stenosis >70%' and whether Vascular Studies Units in the United Kingdom used ECST or NASCET measurement methods. DESIGN: Questionnaire to 102 members of the Society of Vascular Technology of Great Britain and Ireland. RESULTS: One quarter (26%) of respondents reported that their unit used the NASCET measurement method, 31% used the ECST method, while 43% did not know. When all velocity criteria were pooled and compared, an almost equal proportion of ECST, NASCET and 'do not know' respondents used a peak systolic velocity threshold of >230 cm/s as being diagnostic of a 'stenosis >70%'. Interestingly, this velocity is now the threshold proposed by a North American consensus group for diagnosing a NASCET stenosis of >70%. CONCLUSIONS: This audit suggests that there is considerable confusion about what constitutes an ultrasound based diagnosis of 'stenosis >70% in the United Kingdom.     

Comparison of North American Symptomatic Carotid Endarterectomy Trial and population-based outcomes for carotid endarterectomy

Purpose: The North American Symptomatic Carotid Endarterectomy Trial (NASCET) advocated the use of carotid endarterectomy (CEA) for transient ischemic attacks (TIAs), nondisabling strokes, and ipsilateral high-grade stenosis in highly selected patients. Whether similar results are achieved when CEA is applied to an entire geographically defined population is unknown but important if the NASCET recommendations are to be applied broadly to all community patients. Methods: To determine the survival rate to ipsilateral stroke after CEA for all symptomatic patients in a defined population, we reviewed the medical records of all patients residing in Olmsted County, Minn. (approximately 100,000), who underwent a CEA for TIA or nondisabling stroke between 1970 and 1995. Their outcomes were compared with the NASCET results. Results: In the community of Olmsted County, 297 patients (108 women and 189 men) underwent 322 CEAs during the study period. TIAs or nondisabling stroke was the indication in 254 patients (86%), whereas the remaining 14% had asymptomatic stenosis. After CEA for symptomatic lesions, survival rate free of ipsilateral stroke was 97% at 2 years, 93% at 5 years, and 92% at 10 years. These results are similar to the NASCET survival rates free of ipsilateral stroke at 2 years (91%). However, the 30-day postoperative stroke rate for patients older than 80 years was significantly higher than that for patients younger than 80 years. Conclusions: When the NASCET results are compared with a population-based experience in which all symptomatic patients undergoing CEA were analyzed, the early outcomes were similar. Our population-based data also document the remarkably durable long-term results of CEA in preventing stroke and present another benchmark for carotid stent angioplasty. (J Vasc Surg 1998;27:845-51.)     

Behandlung der Karotisstenose durch Stentimplantation

The incidence of arterioarterial stroke originating from the supra-aortic branches is 187/100,000/year.The 90-day prognosis shows a probability of 15% mortality and 19% severe disability. Based on the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST), the indications for endarterectomy have a high level of evidence. Recommendations for carotid endarterectomy depending on the perioperative risk are defined in the American Heart Association (AHA) and European Stroke Initiative (EUSI) proposals. Several trials have shown that stent supported carotid angioplasty is now an almost equivalent alternative for short-term and intermediate-term follow-up, and an even safer alternative technique in surgically high risk patients. However, the following contraindications must be taken into consideration: thrombosis of the internal carotid artery, long stenoses, aneurysms of the aortic arch with involvement of the supra-aortic branches, carotid occlusion in cases of maintenance of the branchial artery coiling of the internal exit area, as well as severe contrast medium allergy. For the endovascular surgeon this implies the need to learn about and to be involved in using this challenging technique. This therapeutic option allows patient oriented therapy and may further reduce the overall complication rate of carotid stenosis therapy.     

Temporal Trends in the Risks of Stroke and Death due to Endarterectomy for Symptomatic Carotid Stenosis: An Updated Systematic Review

ObjectivesTo determine whether there is any evidence of a systematic reduction in the operative risk of carotid endarterectomy (CEA) for symptomatic stenosis in recent years.MethodsWe performed a systematic review of all studies published between 2000 and 2008 inclusive that reported the risks of stroke and death for symptomatic carotid stenosis. We compared the reported risks with our previous review of studies published prior to 2001 and between studies that were reported by surgeons alone and studies that included neurologists or stroke physicians as assessors/authors, with particular reference to the proportion of operative strokes to operative deaths.ResultsOf 494 studies, only 53 reported operative risks for patients with symptomatic stenosis separately. In keeping with the findings of our previous review, the pooled operative risk of stroke and death reported in studies published by surgeons alone (3.9%, 95% confidence interval (CI): 3.4–4.3) was significantly lower (p < 0.001) than that reported in studies that involved neurologists (5.6%, 95% CI: 5.1–6.2). The pooled ratio of operative stroke:operative death was 4.0 (range: 3.6–4.5) in studies involving neurologists or stroke physicians and 2.7 (range: 2.1–3.9) in studies involving only surgeons (p = 0.002). We found no evidence of a reduction in published risks of death or stroke and death due to CEA for symptomatic carotid stenosis between 1985 and 2008. Indeed, the 1.4% (range: 1.2–1.6%) pooled operative mortality in studies published during 2001–2008 was significantly higher than that reported in ECST and NASCET (1.0%, 95% CI: 0.9–1.1%). However, the average age of patients having CEA has continued to increase during this period.ConclusionsThere is no evidence of a systematic reduction over the last decade in the published risks due to CEA for symptomatic stenosis. The lower proportion of non-fatal operative strokes in surgeon-only studies suggests that some minor operative strokes have been missed.     

Helical CT angiography in the preoperative evaluation of carotid artery stenosis

Purpose: To determine the utility and accuracy of helical CT angiography (CTA) in the evaluation of carotid artery stenosis. Methods: A comparison of CTA and conventional arteriogram was performed in 53 patients undergoing evaluation for carotid artery stenosis. Ninety-six carotid systems were evaluable. CTA stenosis was determined by the percent of area reduction seen on axial images through the level of greatest narrowing. MIP images were used to identify the point of maximal stenosis and to visualize overall vascular anatomy. The percent diameter stenosis was measured on conventional arteriograms using strict North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) criteria. Results: Significant correlation was found between CTA and arteriography (NASCET method R = 0.87, ECST method R = 0.87, p < 0.001). Using NASCET >60% as an indicator for disease, CTA had a sensitivity of 87%, specificity of 90%, accuracy of 89%, negative predictive value of 88%, and positive predictive value of 89%. CTA identified plaque characteristics such as ulcerations (8), occlusion (10), fatty plaques (22), calcifications (48), and fibrosis (2). CTA underestimated 2 cases of short segment stenoses because of volume averaging, but this discrepancy was detected by duplex scan. No complications or renal dysfunction occurred with CTA; 1 patient became symptomatic during arteriography, necessitating termination of the procedure. Conclusion: CTA is a safe, non-invasive technique that precisely measures carotid artery area reduction and highly correlates to conventional arteriography. With this new technology, the current standards for carotid artery imaging may need to be reevaluated, and the precise role for helical CTA more clearly defined. (J Vasc Surg 1998;28:290-300.)     

Carotid artery angioplasty and use of stents in high-risk patients with contralateral occlusions.

OBJECT: The risks associated with carotid endarterectomy (CEA) are increased in the presence of contralateral carotid artery (CA) occlusion. The 30-day stroke and death rate for patients in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) who had contralateral CA occlusion was 14.3%. The authors analyze their experience with angioplasty and/or stent placement in patients with contralateral CA occlusion to determine the safety and efficacy of endoluminal revascularization in this subgroup. METHODS: Twenty-six procedures were evaluated in 23 patients with high-grade CA stenosis and contralateral CA occlusion. The first 15 procedures were evaluated retrospectively, and the next 11 prospectively. All patients had severe medical comorbidities and were considered too high risk for CEA, even without considering the contralateral occlusion. Clinical follow-up review was performed an average of 18 months later (median 15 months). CONCLUSIONS: The average ipsilateral CA stenosis according to NASCET criteria was 78% preprocedure and 5% postprocedure. There were no changes in neurological or functional outcome immediately postoperatively in any patient. The 30-day postoperative stroke and death rates were zero. However, there was one symptomatic femoral hematoma that resolved without surgery. At follow up, there were three patients who had suffered stroke or death. One patient died secondary to respiratory arrest at 2 months; one died secondary to prostate carcinoma at 12 months; and one patient experienced a minor stroke contralateral to the treated artery at 41 months. Despite the substantial preoperative risk factors in patients in this series, the 30-day stroke and death rate for angioplasty and/or stent placement appears to be lower than that of CEA in patients with contralateral occlusions.     

Is the rationale for carotid angioplasty and stenting in patients excluded from NASCET/ACAS or eligible for ARCHeR justified?

PURPOSE: To compare outcome after carotid endarterectomy (CEA) in patients who would have been excluded from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) or the Asymptomatic Carotid Atherosclerosis Study (ACAS) or would have been eligible for Acculink for Revascularization of Carotids in High Risk Patients (ARCHeR), a current high-risk stent registry, with outcome in a similar cohort at low risk. METHODS: Records of all CEAs performed at our institution from July 1993 to December 2000 were reviewed. Patients were assigned to groups either eligible or ineligible for NASCET and ACAS or ARCHeR, and criteria were stratified according to whether risk was defined by anatomic or medical problems or whether patients were ineligible according to nonmedical protocol exclusion criteria only. RESULTS: Preoperative and postoperative data were sufficient to determine risk status according to various study criteria in 857 patients. Stroke or death within 30 days, the primary end point, occurred in 2.1% of patients. Rates were similar in patients excluded from (2.7%) or included in (1.6%) NASCET and ACAS and in patients eligible (3.1%) or ineligible (2.1%) for ARCHeR. Rates did not differ according to whether exclusion or inclusion was based on anatomic risk, medical risk, or protocol exclusion, although trends favored worse outcome in the ARCHeR medical risk subgroup. A higher rate of minor complications was found in the elderly; however, stroke and death rates were similar according to age, gender, repeat procedure, or the presence of contralateral occlusion. CONCLUSIONS: No statistically or clinically significant differences were found in combined 30-day stroke or death rates after CEA in any group defined by previous surgical trials or current ongoing high-risk stent registry. While high-risk groups may exist, the premise that operative risk is higher in patients excluded from NASCET and ACAS or eligible for ARCHeR is not supported.     

Carotid endarterectomy remains the gold standard

BACKGROUND: To compare the safety and efficacy of carotid endarterectomy (CEA) as performed in a community medical center with the Asymptomatic Carotid Atherosclerosis Study (ACAS) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) standards and with representative published results regarding carotid angioplasty and stenting (CAS). METHODS: Between 1 January 1994 and 31 July 2000, 267 CEA procedures were performed on 236 patients at Madigan Army Medical Center (MAMC). Prospectively acquired patient demographics, operative indications, and surgical outcomes were reviewed using clinical records, carotid duplex evaluations, and follow-up examinations. The resultant data were compared with ACAS, NASCET, and published results of CAS. RESULTS: The perioperative stroke rate was 2.2% (6 of 267) overall, 0.7% (1 of 139) among asymptomatic patients, and 3.9% (5 of 128) among symptomatic patients. There were no perioperative deaths from any cause in the entire series. The respective ACAS and NASCET early stroke-death rates were 2.3% (19 of 825) and 5.8% (19 of 328). The largest published series of CAS reported stroke-death rates of 5.7% (299 of 5,210) overall, and 3.4% (46 of 1,361) and 5.8% (93 of 1,614) for asymptomatic and symptomatic patients, respectively. CONCLUSIONS: CEA remains the standard of care. It is a safe, effective, and durable procedure that can be performed in a facility such as MAMC with outcomes that compare favorably with ACAS and NASCET. Results of CEA at MAMC are superior to similar data regarding CAS. Widespread use of CAS should be deferred pending completion of on-going prospective trials versus CEA.     

Variability in measurement of internal carotid artery stenosis by arch angiography and duplex ultrasonography--time for a reappraisal?

OBJECTIVES: to determine the inter- and intra-observer variability of ICA stenosis measurement using duplex, ECST and NASCET methods. DESIGN: a retrospective review of arch angiograms and carotid duplex scans in 50 patients. MATERIALS AND METHODS: carotid stenoses were calculated by three independent observers according to NASCET and ECST methods. Variation between observers for NASCET and ECST was determined. For each observer, the variation between NASCET and ECST was determined. The variation between duplex and both NASCET and ECST was determined. RESULTS: inter-observer agreement on the degree of ICA stenosis was clinically and statistically good for NASCET but was poorer for ECST. For each observer, comparison between NASCET and ECST showed 95% limits of agreement of around 50 percentage points. Comparison of duplex with NASCET and ECST showed similar 95% limits of agreement. CONCLUSIONS: arch angiography allows reproducible measurement of carotid stenosis by the NASCET method between different observers. For the ECST method, reproducibility is not so good. Variations in results between NASCET and ECST and between angiography and duplex are significant. In view of the similar results of the NASCET and ECST trials, this suggests that degree of stenosis may only be a surrogate marker for outcome following carotid endarterectomy.     

Effect of urgent carotid endarterectomy on operative risk and benefit

Objectives:The time of Carotid intervention for recently symptomatic,severe carotid stenosis which cause a transient ischemic attack or minor stroke is still a controversial issue.Early studies showed that carotid endarterectomy (CEA) caused a high risk if performed within days follow an acute ischemic stroke.However,The National Stroke Strategy posted by UK Department of Health advocated that this situation should be regarded as an emergency procedure,and carotid intervention should ideally be performed within 48 hours.We designed this study to discuss the effect of urgent CEA on operative risk and benefit.Methods: we analyze 12 urgent CEA with primary closure performed during 1996 to 1998.All 12 patients were underwent CEA within 2 weeks,and 2 of them within 2 days.Operative risks and overall benefit from surgery were discussed in relation to the time from the last symptomatic event to CEA.Results: 2 urgent CEA performed in 2 days are recovery uneventful.1 of 12 patients,who underwent urgent CEA within 2 weeks,occurred restenosis after 3 months follow up.No 30-day perioperative recurrent TIA,stroke and death.Conclusions:CEA performed within 2 weeks is feasible and reliable procedure in preventing recurrent TIA and stroke after presenting manifestations.The future aim is to perform CEA within 48 hours after TIA or stroke symptoms.     

Cost of treating high-risk symptomatic carotid artery stenosis: stent insertion and angioplasty compared with endarterectomy

OBJECT: Definitive data characterizing the safety and efficacy of carotid angioplasty with stent placement (CAS) for symptomatic, occlusive carotid artery (CA) disease require further refinements and standardization of techniques as well as large prospective studies on a par with the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Despite the absence of such data, many surgeons have performed angioplasty and stent placement in patients with clinical or anatomical features known to add significant perioperative risk and capable of disqualifying the patients from participation in NASCET. There exists no cost analysis comparing high-risk endarterectomy with percutaneous angioplasty and stent insertion. METHODS: Forty-five patients (29 men and 16 women) with high-risk, symptomatic CA stenosis have been treated with CAS at the authors' institution since 1996. Indications for this procedure included symptomatic recurrent stenosis following CA endarterectomy (CEA), active coronary disease, high CA bifurcation, and severe medical comorbidities. A longstanding CEA computer database was screened for control patients with similar risk factors; 391 patients (276 men and 115 women) were identified. Actual cost data, duration of hospital stay, and relevant clinical data from the time of treatment until hospital discharge were collected in each patient. The median total cost of CAS was dollar 10,628, whereas that for CEA was dollar 10,148 (p = 0.495). CONCLUSIONS. In patients with high-risk, NASCET-ineligible CA stenosis there was no overall statistically significant cost difference between CEA and CAS. Given that there may not be a cost advantage for either procedure, procedural risk, efficacy, and durability should be key factors in determining the optimal treatment strategy.     

Indikationen zur Therapie von Stenosen der A. carotis

The annual stroke risk for patients with asymptomatic stenoses of the carotid artery is around 1% in case of <70% stenosis (NASCET criteria) and 2-5% in patients with >70% stenosis. The risk of recurrent ischemic events for patients with symptomatic stenoses is much higher, around 15% during the first year. For more than 10 years, the efficacy of carotid surgery has been proven, and there is growing evidence to support surgery in case of asymptomatic stenosis. Patients with severe stenoses, male or elderly patients, and those with bilateral stenoses benefit more from surgery. Carotid artery stenting has not proven its safety or efficacy. Despite this lack of evidence, the method is used in many centers as an alternative to surgery. Especially symptomatic carotid artery stenosis should be used mainly in the setting of a randomized trial such as SPACE.