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Objective: Despite the publication of various national/international guidelines, several questions concerning the management of patients with asymptomatic (AsxCS) and symptomatic (SxCS) carotid stenosis remain unanswered. The aim of this international, multi-specialty, expert-based Delphi Consensus document was to address these issues to help clinicians make decisions when guidelines are unclear., Methods: Fourteen controversial topics were identified. A three-round Delphi Consensus process was performed including 61 experts. The aim of Round 1 was to investigate the differing views and opinions regarding these unresolved topics. In Round 2, clarifications were asked from each participant. In Round 3, the questionnaire was resent to all participants for their final vote. Consensus was reached when ≥75% of experts agreed on a specific response., Results: Most experts agreed that: (1) the current periprocedural/in-hospital stroke/death thresholds for performing a carotid intervention should be lowered from 6% to 4% in patients with SxCS and from 3% to 2% in patients with AsxCS; (2) the time threshold for a patient being considered "recently symptomatic" should be reduced from the current definition of "6 months" to 3 months or less; (3) 80% to 99% AsxCS carries a higher risk of stroke compared with 60% to 79% AsxCS; (4) factors beyond the grade of stenosis and symptoms should be added to the indications for revascularization in AsxCS patients (eg, plaque features of vulnerability and silent infarctions on brain computed tomography scans); and (5) shunting should be used selectively, rather than always or never. Consensus could not be reached on the remaining topics due to conflicting, inadequate, or controversial evidence., Conclusions: The present international, multi-specialty expert-based Delphi Consensus document attempted to provide responses to several unanswered/unresolved issues. However, consensus could not be achieved on some topics, highlighting areas requiring future research., Competing Interests: Disclosures D.P.M. has given talks, acted as a consultant or attended conferences sponsored by Amgen and Novo Nordisk. J.F.M. receives funding from the United States National Institute of Neurologic Disorders and Stroke for work related to running the CREST-2 clinical trial (U01NS080168) and the CREST-2 Long-term Observational Extension study (U01NS119169). E.A.S. has received research grants from the United States Food and Drug Administration, BD, Boston Scientific, Cook, CSI, Laminate Medical, Medtronic and Philips; has received consulting/speaking fees from Abbott, Bayer, BD, Boston Scientific, Cook, Cordis, CSI, Inari, Infraredx, Medtronic, Philips, Shockwave and VentureMed. H.-H.E. is a local Principal Investigator for the ROADSTER 2 trial and a scientific committee member of SPACE-1, SPACE-2 and ACST-2. T.R. is funded by grants from the National Institutes of Health (R01 MD012467, R01 NS029993, R01NS040807, 1U24NS107267), and the National Center for Advancing Translational Sciences (UL1 TR002736, KL2 TR002737). J.S.M. has received institutional research grants from Abbott, Cook, Endologix, Gore and Medtronic., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Current guidelines do not recommend screening for asymptomatic carotid artery stenosis (AsxCS). The rationale behind this recommendation is that detection of AsxCS may lead to an unnecessary carotid intervention. In contrast, screening for abdominal aortic aneurysms is strongly recommended., Methods: A critical analysis of the literature was performed to evaluate the implications of detecting AsxCS., Results: Patients with AsxCS are at high risk for future stroke, myocardial infarction and vascular death. Population-wide screening for AsxCS should not be recommended. Additionally, screening of high-risk individuals for AsxCS with the purpose of identifying candidates for a carotid intervention is inappropriate. Instead, selective screening for AsxCS should be considered and should be viewed as an opportunity to identify individuals at high risk for atherosclerotic cardiovascular disease and future cardiovascular events for the timely initiation of intensive medical therapy and risk factor modification., Conclusions: Although mass screening should not be recommended, there are several arguments suggesting that selective screening for AsxCS should be considered. The rationale supporting such selective screening is to optimize risk factor control and to initiate intensive medical therapy for prevention of future cardiovascular events, rather than to identify candidates for an intervention., Competing Interests: Declaration of Competing Interest All authors are members of the Faculty Advocating Collaborative and Thoughtful Carotid Artery Treatments (FACTCATS; available at www.FACTCATS.org) with the shared goal of optimizing stroke prevention. The views of particular FACTCATS do not necessarily reflect the views of other FACTCATS., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Medical therapy for stroke prevention has improved significantly over the past 30 years. Recent analyses of medically treated cohorts have suggested that early rates of stroke may have reduced, and reports of the safety of carotid surgery have also shown improvements. Since the effectiveness of carotid surgery versus medical therapy was established in the 1990s, there is an urgent need to evaluate whether surgery remains cost-effective in the UK., Methods: A decision model was developed to estimate the lifetime costs and utilities of modern medical therapy with and without carotid endarterectomy in patients with symptomatic stenosis from the perspective of the UK National Health Service. The base-case population consisted of adults aged 70 years with 70-99 per cent stenosis. Model data were obtained from clinical studies and wider literature. Univariate and probabilistic sensitivity analyses were carried out., Results: In the base-case scenario, the 5-year absolute risk reduction with carotid endarterectomy was 5 per cent, and the incremental cost-effectiveness ratio was €12 021 (exchange rate £1 GBP = €1.1125 (Tuesday 1 January 2019)) per quality-adjusted life-year. Surgery was more cost-effective if performed rapidly after presentation. In patients with 50-69 per cent carotid stenosis, surgery appeared less clinically effective. However, there was considerable uncertainty., Conclusion: Surgery may not now be clinically effective and cost-effective in those with moderate carotid stenosis. However, these results are uncertain because of the limited data on modern medical therapy and an RCT may be justified., (© The Author(s) 2022. Published by Oxford University Press on behalf of BJS Society Ltd. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Despite the publication of several national/international guidelines, the optimal management of patients with asymptomatic carotid stenosis (AsxCS) remains controversial. This article compares 3 recently released guidelines (the 2020 German-Austrian, the 2021 European Stroke Organization [ESO], and the 2021 Society for Vascular Surgery [SVS] guidelines) vs the 2017 European Society for Vascular Surgery (ESVS) guidelines regarding the optimal management of AsxCS patients.The 2017 ESVS guidelines defined specific imaging/clinical parameters that may identify patient subgroups at high future stroke risk and recommended that carotid endarterectomy (CEA) should or carotid artery stenting (CAS) may be considered for these individuals. The 2020 German-Austrian guidelines provided similar recommendations with the 2017 ESVS Guidelines. The 2021 ESO Guidelines also recommended CEA for AsxCS patients at high risk for stroke on best medical treatment (BMT), but recommended against routine use of CAS in these patients. Finally, the SVS guidelines provided a strong recommendation for CEA+BMT vs BMT alone for low-surgical risk patients with >70% AsxCS. Thus, the ESVS, German-Austrian, and ESO guidelines concurred that all AsxCS patients should receive risk factor modification and BMT, but CEA should or CAS may also be considered for certain AsxCS patient subgroups at high risk for future ipsilateral ischemic stroke.

The recommendations of international guidelines for the management of asymptomatic carotid stenosis (ACS) often vary considerably and extend from a conservative approach with risk factor modification and best medical treatment (BMT) alone, to a more aggressive approach with a carotid intervention plus BMT. The aim of the current multispecialty position statement was to reconcile the conflicting views on the topic. A literature review was performed with a focus on data from recent studies. Several clinical and imaging high-risk features have been identified that are associated with an increased long-term ipsilateral ischemic stroke risk in patients with ACS. Such high-risk clinical/imaging features include intraplaque hemorrhage, impaired cerebrovascular reserve, carotid plaque echolucency/ulceration/ neovascularization, a lipid-rich necrotic core, a thin or ruptured fibrous cap, silent brain infarction, a contralateral transient ischemic attack/stroke episode, male patients <75 years and microembolic signals on transcranial Doppler. There is growing evidence that 80-99% ACS indicate a higher stroke risk than 50-79% stenoses. Although aggressive risk factor control and BMT should be implemented in all ACS patients, several high-risk features that may increase the risk of a future cerebrovascular event are now documented. Consequently, some guidelines recommend a prophylactic carotid intervention in high-risk patients to prevent future cerebrovascular events. Until the results of the much-anticipated randomized controlled trials emerge, the jury is still out regarding the optimal management of ACS patients.

The optimal management of patients with asymptomatic carotid stenosis (ACS) is the subject of extensive debate. According to the 2017 European Society for Vascular Surgery Guidelines, carotid endarterectomy should (Class IIa; Level of Evidence: B) or carotid artery stenting may be considered (Class IIb; Level of Evidence: B) in the presence of one or more clinical/imaging characteristics that may be associated with an increased risk of late ipsilateral stroke (e.g. silent embolic infarcts on brain computed tomography/magnetic resonance imaging, progression in the severity of ACS, a history of contralateral transient ischemic attack/stroke, microemboli detection on transcranial Doppler, etc.), provided documented perioperative stroke/death rates are <3% and the patient's life expectancy is >5 years. Besides these clinical/imaging characteristics, there are additional individual, ethnic/racial or social factors that should probably be evaluated in the decision process regarding the optimal management of these patients, such as individual patient needs/patient choice, patient compliance with best medical treatment, patient sex, culture, race/ethnicity, age and comorbidities, as well as improvements in imaging/operative techniques/outcomes. The present multispecialty position paper will present the rationale why the management of patients with ACS may need to be individualized.

Transient ischaemic attack secondary to carotid stenosis has the highest risk of stroke recurrence compared with other aetiological subtypes. International guidelines advocate carotid intervention within one to two weeks of the index neurological event. Traditionally, delayed carotid intervention was perceived to be a safer management strategy, yet classic trials of endarterectomy and recent meta-analysis of carotid intervention demonstrate the safety of hyperacute carotid intervention. Data from international studies suggest that targets are not being met, the reasons for which are multifactorial, but patients suffering transient or ocular symptoms are particularly delayed. Efforts should be made to conduct regional studies investigating the root causes of delayed intervention, with subsequent policy adjustment to expedite intervention, and interim optimisation of medical management to reduce the incidence of recurrent stroke., (© The Author(s) 2016.)

Objective: Stroke is a major cause of death and disability. That three-quarters of stroke patients will never have previously manifested cerebrovascular symptoms demonstrates the unmet clinical need for new biomarkers able to stratify patient risk and elucidation of the biological dysregulations. In this study, the utility of comprehensive metabolic phenotyping is assessed to provide candidate biomarkers that relate to stroke risk in stenosing carotid plaque tissue samples., Method: Carotid plaque tissue samples were obtained from patients with cerebrovascular symptoms of carotid origin (n = 5), and from asymptomatic patients (n = 5). Two adjacent biological replicates were obtained from each tissue. Organic and aqueous metabolite extracts were obtained separately and analysed using two ultra performance liquid chromatography coupled to mass spectrometry metabolic profiling methods. Multivariate and univariate tools were used for statistical analysis., Results: The two study groups demonstrated distinct plaque phenotypes using multivariate data analysis. Univariate statistics also revealed metabolites that differentiated the two groups with a strong statistical significance (p = 10(-4)-10(-5)). Specifically, metabolites related to the eicosanoid pathway (arachidonic acid and arachidonic acid precursors), and three acylcarnitine species (butyrylcarnitine, hexanoylcarnitine, and palmitoylcarnitine), intermediates of the β-oxidation, were detected in higher intensities in symptomatic patients. However, metabolites implicated in the process of cell death, a process known to be upregulated in the formation of the vulnerable plaque, were unaffected., Conclusions: Discrimination between symptomatic and asymptomatic carotid plaque tissue is demonstrated for the first time using metabolic profiling technologies. Two biological pathways (eicosanoid and β-oxidation) were implicated in differentiating symptomatic from asymptomatic patients and will be further investigated. These results indicate that metabolic phenotyping should be further explored to investigate the chemistry of the unstable plaque, in the pursuit of candidate biomarkers for risk-stratification and targets for pharmacotherapeutic intervention., (Copyright © 2016. Published by Elsevier Ltd.)

Objectives: Thrombolysis is effective in improving clinical outcome in the treatment of acute ischaemic stroke. However, thrombolysis results in low recanalisation rates, particularly in the event of carotid occlusion. Carotid intervention is indicated in stroke resulting from significant carotid atherosclerosis, but intervention soon after thrombolysis may be associated with increased risks. This study aims to assess the safety of carotid intervention post-thrombolysis for acute ischaemic stroke., Design: Systematic review., Materials and Methods: MEDLINE and EMBASE were searched on 29 May 2014. Inclusion criteria were (i) intra-arterial or intravenous thrombolysis for acute ischaemic stroke; (ii) carotid intervention within 14 days of thrombolysis; and (iii) derivable primary outcome. The primary outcome was 30-day stroke or death. A meta-analysis of incidence was completed for the 30-day stroke or death rates using Freeman-Tukey arcsine transformations and assuming random effects. Point estimates with confidence intervals (CIs) were generated and heterogeneity was assessed. The strength of recommendations and quality of underlying evidence were assessed using the American College of Chest Physicians (ACCP) grading system., Results: Nine included publications recorded 114 carotid endarterectomy (CEA) and four angioplasty interventions. The point estimate of 30-day stroke or death for CEA was 4.93% (95% CI 1.83-9.44), representing four of 114. The strength of recommendation and quality of underlying evidence for CEA as per the ACCP grading system was determined as 1C. There were no cases of stroke or death in patients undergoing angioplasty post-thrombolysis (0/4)., Conclusions: Early CEA post-thrombolysis appears safe, with stroke or death rates similar to that of the operation without thrombolysis. However, the wide CI obtained highlights the uncertainty of this result. Further, we emphasise that this recommendation is supported by low-quality evidence. Additional data are required to confirm the safety of surgery and early endovascular therapy post-thrombolysis., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Benefit from carotid endarterectomy (CEA) in symptomatic moderate (50-69 per cent) carotid stenosis remains marginal. The Fourth National Clinical Guideline for Stroke recommends use of the risk score from the European Carotid Surgery Trial (ECST) to aid decision-making in symptomatic carotid disease. It is not known whether clinicians are, in fact, influenced by it., Methods: Using the ECST risk prediction model, three scenarios of patients with a low (less than 10 per cent), moderate (20-25 per cent) and high (40-45 per cent) 5-year risk of stroke were devised and validated. Invitations to complete an online survey were sent by e-mail to vascular surgeons and stroke physicians, with responses gathered. The questionnaire was then repeated with the addition of the ECST risk score., Results: Two hundred and one completed surveys were analysed (21·5 per cent response rate): 107 by stroke physicians and 94 by vascular surgeons. The high-risk scenario after the introduction of the ECST risk score showed an increased use of CEA (66·7 versus 80·1 per cent; P = 0·009). The low-risk scenario after risk score analysis demonstrated a swing towards best medical therapy (23·4 versus 57·2 per cent; P < 0·001). CEA was preferred in the moderate-risk scenario and this was not altered significantly by introduction of the risk score (71·6 versus 75·6 per cent; P = 0·609). Vascular surgeons exhibited a preference towards CEA compared with stroke physicians in both low- and moderate-risk scenarios (P < 0·001 and P = 0·003 respectively)., Conclusion: The addition of a risk score appeared to influence clinicians in their decision-making towards CEA in high-risk patients and towards best medical therapy in low-risk patients., (© 2014 BJS Society Ltd. Published by John Wiley & Sons Ltd.)

The annual rate of ipsilateral stroke associated with asymptomatic carotid stenosis has fallen from 2-4% to <1% in the last 20 years due to improvements in medical therapy. The fundamental benefits of this are relevant to whether patients undergo revascularisation or not. We aimed to evaluate existing international guidelines for the management of carotid stenosis, identifying important similarities and differences. The websites of the American Heart Association, Society for Vascular Surgery, European Society for Cardiology, European Society for Vascular Surgery, British Cardiovascular Society and UK Vascular Society were searched for guidelines relating to primary prevention for asymptomatic atherosclerotic carotid disease in September 2011 and independently reviewed by 2 authors. The following guidelines were identified and compared: The Joint British Societies 2nd (JBS2) 2005 guideline, the 4th European Society for Cardiology (ESC) 2007 guideline, the joint American Heart Association/Society for Vascular Surgery (AHA/SVS) guideline 2011 and subsequent 2011 SVS update, the American Heart Association (AHA) prevention of stroke guideline 2010, the AHA secondary prevention for atherosclerotic coronary and vascular disease 2011 update, and the European Society for Vascular Surgery (ESVS) Section A carotid guideline. There was no UK guidance from its vascular society. Important differences were evident in methods of risk assessment, treatment targets for blood pressure and low density lipoprotein cholesterol, and the use of anti-platelet agents. These differences are highlighted in 2 case scenarios. There is now clear, evidence based guidance from British, European and US cardiovascular bodies regarding optimal targets for risk factor modification. These can be adopted as standard operating procedure for clinical practice and the medical arms of carotid interventional trials. In the future imaging biomarkers may help provide an understanding of the risk of an individual carotid lesion to help guide therapy.

Background: The aim of this study was to model the cost-effectiveness of carotid endarterectomy for asymptomatic stenosis versus medical therapy based on 10-year data from the Asymptomatic Carotid Surgery Trial (ACST)., Methods: This was a cost-utility analysis based on clinical effectiveness data from the ACST with UK-specific costs and stroke outcomes. A Markov model was used to calculate the incremental cost-effectiveness ratio (ICER, or cost per additional quality-of-life year) for a strategy of early endarterectomy versus medical therapy for the average patient and published subgroups. An exploratory analysis considered contemporary event rates., Results: The ICER was £7584 per additional quality-adjusted life-year (QALY) for the average patient in the ACST. At thresholds of £20,000 and £30,000 there was a 74 and 84 per cent chance respectively of early endarterectomy being cost-effective. The ICER for men below 75 years of age was £3254, and that for men aged 75 years or above was £71,699. For women aged under 75 years endarterectomy was less costly and more effective than medical therapy; for women aged 75 years or more endarterectomy was less effective and more costly than medical therapy. At contemporary perioperative event rates of 2·7 per cent and background any-territory stroke rates of 1·6 per cent, early endarterectomy remained cost-effective., Conclusion: In the ACST, early endarterectomy was predicted to be cost-effective in those below 75 years of age, using a threshold of £20,000 per QALY. If background any-territory stroke rates fell below 1 per cent per annum, early endarterectomy would cease to be cost-effective., (Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)

Objective: Robust guidelines exist for the treatment of carotid stenosis and intracranial aneurysms independently, however, the management of tandem carotid stenosis and intracranial aneurysms remains uncertain. Although the prevalence of tandem pathologies is small (1.9%-3.2%), treating carotid stenosis can alter intracranial hemodynamics potentially predisposing to aneurysm rupture. In this review, our aim was to assess the safety of intervention in this cohort, by analyzing outcomes from the published literature., Methods: The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to conduct the review. Articles from 1947 to 2012 were searched using EMBASE Classic and EMBASE (November, 1947 -March, 2012) and Ovid MEDLINE(R) In-Process and other NonIndexed Citations and Ovid MEDLINE(R) on Ovid SP, http://ClinicalTrials.gov, http://controlled-trials.com and the Cochrane review database using a predefined search strategy., Results: One hundred forty-one patients from 27 articles were included. Interventions ranged from single (n=104, 74%), staged (n=26, 18%) to simultaneous procedures (n=11, 8%). The largest cohort of patients was treated by carotid endarterectomy alone (n=92, 66%). The majority of patients presented with a symptomatic carotid stenosis and an asymptomatic ipsilateral intracranial aneurysm (n=70, 50%). Five subarachnoid hemorrhages occurred (4% [5/140], three within 30 days of the procedure and two thereafter) of which two were fatal. All five occurred in patients who underwent carotid endarterectomy as a single procedure (5%). Two of the five patients presented with ruptured posterior communicating artery aneurysms., Conclusions: Published reports of perioperative aneurysm rupture are rare in individuals with tandem carotid stenosis and intracranial aneurysms. This is the first analysis of all published cases. However, it is limited by the small number of studies and the possible underreporting due to publication bias and underdiagnosis where angiography was not performed. Although we report a low incidence of subarachnoid hemorrhage, analysis of registry data with a larger cohort is warranted to confirm these findings., (Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Background: Treatment of head and neck malignancy commonly involves radiotherapy, which is associated with the development of carotid artery stenosis. There is little evidence to guide clinicians on how to intervene in significant postradiotherapy carotid stenosis. This systematic review collated data pertaining to perioperative outcomes of carotid artery surgery and carotid stenting in postradiotherapy carotid stenosis to aid the clinical decision-making process., Methods: A systematic review of the literature, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines, was performed. We screened 575 articles related to carotid artery surgery or stenting in postradiotherapy carotid stenosis, from which 21 studies were included for quantitative analysis. The primary outcome was stroke or death ≤ 30 days of the procedure. Secondary outcomes included cranial nerve injury, restenosis, stroke, and death at >30 days., Results: Nine publications recorded 211 surgical procedures in 179 patients. In symptomatic patients, the 30-day mortality rate was 2.6% and the stroke or death rate was 2.7%. In asymptomatic patients, the 30-day mortality rate was 0% and the stroke or death rate was 1.1%. Permanent cranial nerve palsy was experienced by 0.6% of patients. Twelve publications recorded 510 carotid artery stenting procedures in 482 patients. In symptomatic patients, the 30-day mortality rate was 5.1%, and the stroke or death rate was 5.1%. In asymptomatic patients, the 30-day mortality rate was 1.4%, and the stroke or death rate was 2.1%. There was no statistically significant difference in 30-day stroke or death rate between surgical revascularization and carotid artery stenting in all (odds ratio [OR], 0.54; 95% confidence interval [CI] 0.17-1.70; P = .43), symptomatic (OR, 0.52; 95% CI, 0.14-1.98; P = .38), or asymptomatic patients (OR, 0.55; 95% CI, 0.06-5.42; P = .99)., Conclusions: The published outcomes from high-volume centers demonstrate that surgical revascularization and stenting are both technically feasible in postradiotherapy carotid stenosis and have similar safety profiles to nonirradiated necks. Radiation should therefore not be considered a contraindication to surgical intervention., (Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Aims: We sought to determine whether intraplaque inflammation could be measured with positron emission tomography/computed tomography angiography (PET/CTA) using (11)C-PK11195, a selective ligand of the translocator protein (18 kDa) (TSPO) which is highly expressed by activated macrophages., Methods and Results: Patients (n = 32; mean age 70 ± 9 years) with carotid stenoses (n = 36; 9 symptomatic and 27 asymptomatic) underwent (11)C-PK11195 PET/CTA imaging. (11)C-PK11195 uptake into carotid plaques was measured using target-to-background ratios (TBR). On CTA images, plaque composition was assessed by measuring CT attenuation of the carotid plaque. Eight patients underwent carotid endarterectomy and ultrathin contiguous sections were processed for TSPO and CD68 (using immunohistochemical staining, (3)H-PK11195 autoradiography, and confocal fluorescence microscopy). Carotid plaques associated with ipsilateral symptoms (stroke or transient ischaemic attack) had higher TBR (1.06 ± 0.20 vs. 0.86 ± 0.11, P = 0.001) and lower CT attenuation [(median, inter-quartile range) 37, 24-40 vs. 71, 56-125 HU, P = 0.01] than those without. On immunohistochemistry and confocal fluorescence microscopy, CD68 and PBR co-localized with (3)H-PK11195 uptake at autoradiography. There was a significant correlation between (11)C-PK11195 TBR and autoradiographic percentage-specific binding (r = 0.77, P = 0.025). Both TBR and CT plaque attenuation had high negative predictive values (91 and 92%, respectively) for detecting symptomatic patients. However, the best positive predictive value (100%) was achieved when TBR and CT attenuation were combined., Conclusion: Imaging intraplaque inflammation in vivo with (11)C-PK11195 PET/CTA is feasible and can distinguish between recently symptomatic and asymptomatic plaques. Patients with a recent ischaemic event had ipsilateral plaques with lower CT attenuation and increased (11)C-PK11195 uptake.

Purpose: To quantify a pseudoenhancement phenomenon observed during dynamic contrast material-enhanced ultrasonography (US) of the carotid artery, both in vitro and in vivo., Materials and Methods: Ethical approval was obtained prior to commencing this prospective case series, and each patient gave written informed consent. Thirty-one patients with 50%-99% internal carotid artery stenosis underwent dynamic contrast-enhanced US of the carotid bifurcation with use of 2 mL of microbubbles. In the final 10 patients, an additional 1 mL bolus was administered after 15 minutes. Raw linear digital imaging and communications in medicine data were analyzed offline. Regions of interest were drawn within the common carotid artery lumen and immediately adjacent to the lumen in the near and far wall adventitia. Peak intensity was measured. An in vitro experiment with a single-channel flow phantom was also performed. This apparatus consisted of an 8-mm-diameter latex tube placed in a tissue-mimicking fluid. Microbubble concentrations of 0.02%, 0.1%, 0.5%, 1%, and 2% were pumped into the tube. Regions of interest were drawn in a similar fashion to the in vivo experiments, and peak intensity was measured. The Wilcoxon signed rank and paired t tests were used to compare the difference between the near and far wall signal intensities at each dose; a multiplication factor comparing near and far wall signal intensity was derived., Results: The far wall of the common carotid artery was significantly more echogenic than the near wall at 2 mL contrast agent doses (P<.0001, n=31), and the far wall signal intensity increased synchronously with that of the lumen. The difference in signal intensity between near and far wall regions was significantly greater at 2 mL than at 1 mL (P=.012, n=10). In vitro, the phantom tubing demonstrated a similar pattern and magnitude of enhancement to that seen in vivo., Conclusion: A dose-dependent, nonlinear propagation artifact known as pseudoenhancement occurs in the far wall adventitia of the carotid artery and should not be mistaken as a marker of plaque vulnerability., (© RSNA, 2011)

Background and Purpose: Development of translational functional imaging modalities for atherosclerosis risk stratification is sought for stroke prediction. Our group has developed late-phase contrast-enhanced ultrasound (LP-CEUS) to quantify microbubble contrast retention within carotid atherosclerosis and shown it to separate asymptomatic plaques from those responsible for recent cerebrovascular events. We hypothesized that microbubbles are retained in areas of plaque inflammation, aiming to examine whether LP-CEUS signal reflects plaque biology., Methods: Subjects awaiting carotid endarterectomy (n=31) underwent axial LP-CEUS and diseased intimal segments were symmetrically divided in the long axis. Half-specimens underwent quantitative immunohistochemical analysis for CD68 (macrophages) and CD31 (angiogenesis). Half-specimens were processed for atheroma cell culture and supernatant collected at 24 hours for multianalyte profiling for 34 analytes., Results: Percentage area immunopositivity was significantly higher in subjects in which normalized plaque late-phase intensity was ≥0 versus <0 (CD68 mean 11.8 versus 6.68, P=0.004; CD31 mean 9.45 versus 4.82, P=0.025). Interleukin-6, matrix metalloproteinase-1, and matrix metalloproteinase-3 were significantly higher by multianalyte profiling when LP-CEUS was ≥0., Conclusions: LP-CEUS reflects biological features of inflammation and angiogenesis, key features predisposing to plaque rupture. Further investigation of LP-CEUS as a tissue-specific marker of inflammation for risk stratification of carotid atherosclerosis is warranted.

Background: Approximately 20% of strokes are attributable to carotid stenosis. However, the number of asymptomatic patients needed to prevent one stroke or death with endarterectomy is high at 17 to 32. There is a clear need to identify asymptomatic individuals at high risk of developing future ischemic events to improve the cost-effectiveness of surgery. Our aim was to examine the evidence for subclinical microembolization and silent brain infarction in the prediction of stroke in asymptomatic carotid stenosis using transcranial Doppler (TCD), computed tomography (CT), and magnetic resonance imaging (MRI)., Methods: The review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Articles regarding humans between 1966 and 2010 were identified through systematic searches of Pubmed, MEDLINE, and EMBASE electronic databases using a predetermined search algorithm., Results: Fifty-eight full text articles met the inclusion criteria. A median of 28% of microemboli positive patients experienced a stroke or transient ischemic attack during follow-up compared with 2% of microemboli negative patients (P = .001). The same was true for the end point of stroke alone with a median of 10% of microemboli positive patients experiencing a stroke vs 1% of microemboli negative patients (P = .004). A specific pattern of silent CT infarctions was related to future stroke risk (odds ratio [OR] = 4.6; confidence interval [CI] = 3.0-7.2; P < .0001). There are no prospective MRI studies linking silent infarction and stroke risk., Conclusions: There is level 1 evidence for the use of TCD to detect microembolization as a risk stratification tool. However, this technique requires further investigation as a stroke prevention tool and would be complemented by improvements in carotid plaque imaging., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objectives: Carotid stenosis accounts for 20% of ischemic strokes and can be managed with pharmacotherapy alone or in conjunction with carotid endarterectomy or stenting. The management of asymptomatic carotid stenosis is controversial amongst physicians. The aim of this study was to explore patient preferences for the potential management options using a standardized scenario to minimize clinician bias. These data will then be used to facilitate comparison with existing published data on physicians' preferences in the management of asymptomatic carotid stenosis., Methods: A patient information booklet and questionnaire was developed, validated, and distributed to patients who were identified as candidates for carotid screening duplex based on the presence of peripheral arterial, coronary, or aneurismal disease. Patients were asked to imagine their duplex revealed a 70% unilateral carotid stenosis. Five-year stroke or death risks of 11% were quoted for best medical therapy. The perioperative stroke or death rates quoted were 3% for endarterectomy and 3% to 5% for stenting, based on best current evidence. No physician interaction was allowed to minimize clinician bias. Responses for treatment preference and reasoning were analyzed using appropriate statistical methods. Results from this survey were then compared with a previously published poll of physician preference., Results: One hundred two questionnaires were analyzed with a 94% response rate: 48% chose pharmacotherapy alone, 30% selected carotid endarterectomy, and 22% opted for stenting. The preference for pharmacotherapy alone over either intervention, and for endarterectomy, over stenting was consistent in subgroup analyses by age, gender, prior stroke, family history of stroke, and smoking status., Conclusion: In this scenario, patients were split equally between medical and surgical treatment of asymptomatic carotid stenosis. This was identical to a recent poll of physicians. Tools for risk assessment and the results of the SPACE2, ACST2, and ACT1 trials would benefit patients and physicians making this important treatment decision., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Introduction: Ambiguity in the literature concerning potential benefits of carotid artery stenting (CAS) as an alternative to carotid endarterectomy (CEA) necessitated a 5-year Delphi-type survey, gauging the changing views over this period of relevant experts undertaking carotid intervention., Methods: Delphi surveys performed in 2004 and 2009 involved 2 rounds of questions combined with feedback of results from the first round between them. The questionnaire was e-mailed to UK vascular surgeons, neurosurgeons, interventional radiologists, and cardiologists., Results: In 2004 and 2009, the second round response rates were 69% and 51%, respectively. Over 5 years, there was a statistically significant reduction in support for ''general anesthesia risk'' and ''contralateral occlusion'' as indications for CAS and views that CAS ''increased patient satisfaction'' and ''decreased the length of hospital stay.'' Concerning the impact of recent trials on the professionals' treatment routines for symptomatic and asymptomatic patients with carotid disease, 65.8% and 76.3%, respectively, had not changed their overwhelming non-CAS routines, with 32.9% and 19.7% saying clinical trial results moved them toward CEA., Conclusions: A 2009 survey of vascular experts found no increase in preference for CAS as a treatment option for advanced carotid bifurcation atherosclerosis. This, in combination with the lack of change from and indeed move toward the ''gold-standard'' CEA, demonstrates a general decline in confidence with CAS.

Introduction: No studies as yet have directly evaluated the patients' perspective of carotid endarterectomy (CEA). Here, we determine patient satisfaction, understanding, and perception of CEA., Methods: Consecutive patients were identified from a prospectively maintained carotid database. A validated 10-point telephone questionnaire was conducted. Questions related to preoperative symptoms, experience of procedure, future interventions, and overall patient satisfaction., Results: Of the 192 patients included, 136 completed the questionnaire (71% response rate). Ninety-two percent were satisfied with the explanation received, however, only 48% understood that CEA aimed to prevent future stroke. Eighty-five percent of patients received local anesthesia (LA) CEA, with 16% reporting severe or unbearable pain. Most patients (83%) would repeat CEA if necessary and 67% stated a future preference for LA CEA. The majority of patients (96%) were satisfied with their treatment overall., Conclusions: Most patients were satisfied with CEA. Greater emphasis could be placed on improving preoperative information-giving and intraoperative analgesia.

Objective: Free-floating thrombus (FFT) of the carotid artery is a rare condition of currently unknown etiology. Less than 150 cases have been described in the published world literature to date., Design and Setting: We present 6 consecutive cases of carotid FFT, identified prospectively from 5000 carotid duplex scans over a 34-month period in a single tertiary center for vascular surgery., Results: All 6 cases involved the left carotid bifurcation in neurologically symptomatic individuals. In 5 of the 6 cases, FFT occurred in the absence of a significantly stenosing atheromatous plaque and was not associated with an elevation in velocity on duplex. The patients were all treated with surgical thromboendarterectomy, with good result., Conclusions: Duplex imaging can underestimate the degree of stenosis. Free-floating thrombus presents a challenge in diagnosis due to its rapidly evolving nature. The management of FFT by acute thromboendarterectomy appears to be safe and effective in limiting further focal neurological sequelae.

Traditionally, stroke risk stratification has centred on the degree of internal carotid artery stenosis, and the presence of focal neurological symptoms. However, degree of stenosis alone is a relatively poor predictor of future stroke in asymptomatic patients; the Asymptomatic Carotid Surgery Trial highlighting the need to identify a subgroup of asymptomatics that may benefit from intervention. Attempting to define this subgroup has inspired imaging research to identify, in vivo, high-risk plaques. In addition to pre-operative risk stratification of carotid stenosis, contrast enhanced ultrasound (CEUS) may be employed in monitoring response to plaque-stabilising therapies. Unlike most contrast agents used for computed tomography and magnetic resonance imaging, microbubbles used in CEUS remain within the vascular space and can hence be used to study the vasculature. In addition to improving current carotid structural scans, CEUS has potential to add extra information on plaque characteristics. Furthermore, by targeting microbubbles to specific ligands expressed on vascular endothelium, CEUS may have the ability to probe plaque biology. This review describes the current carotid ultrasound examination and the need to improve it, rationale for imaging neovascularisation, use of CEUS to image neovascularisation, microbubbles in improving the structural imaging of plaque, potential problems with CEUS, and future directions.

The natural history of patients with carotid artery occlusion is poorly understood, and patients are usually offered conservative treatment as the difficulty and risks of surgical intervention are thought to outweigh the natural history of the condition. The case of a 71-year-old male patient with symptomatic internal carotid artery stenosis in a previously occluded vessel is presented. This case suggests that symptomatic recanalization of an occluded carotid artery may occur and long-term duplex surveillance may be a justifiable strategy in this patient group.

Background and Purpose: The ATP-binding cassette transporter A1 (ABCA1) facilitates cholesterol efflux from cells, a key process in reverse cholesterol transport. Whereas previous investigations focused on mutations causing impaired ABCA1 function, we assessed the role of ABCA1 in human carotid atherosclerotic disease., Methods: We compared the mRNA and protein levels of ABCA1, and one of its key regulators, the liver X receptor alpha (LXRalpha), between minimally and grossly atherosclerotic arterial tissue. We established ABCA1 and LXRalpha gene expression by real-time quantitative polymerase chain reaction in 10 control and 18 atherosclerotic specimens. Presence of ABCA1 protein was assessed by immunoblotting. To determine whether differences observed at a local level were reflected in the systemic circulation, we measured ABCA1 mRNA in leukocytes of 10 patients undergoing carotid endarterectomy and 10 controls without phenotypic atherosclerosis., Results: ABCA1 and LXRalpha gene expression were significantly elevated in atherosclerotic plaques (P<0.0001 and 0.03, respectively). The increased mRNA levels of ABCA1 and LXRalpha were correlated in atherosclerotic tissue (r=0.85; P<0.0001). ABCA1 protein expression was significantly reduced in plaques compared with control tissues (P<0.0001). There were no differences in leukocyte ABCA1 mRNA expression (P=0.67)., Conclusions: ABCA1 gene and protein are expressed in minimally atherosclerotic human arteries. Despite significant upregulation of ABCA1 mRNA, possibly mediated via LXRalpha, ABCA1 protein is markedly reduced in advanced carotid atherosclerotic lesions. No differences in leukocyte ABCA1 expression were found, suggesting the plaque microenvironment may contribute to the differential ABCA1 expression. We propose that the decreased level of ABCA1 protein is a key factor in the development of atherosclerotic lesions.

Background and Purpose: Endoluminal treatment is being increasingly used for carotid artery disease. The aim of this study was to compare the stroke and death risk within 30 days of endovascular treatment or endarterectomy for symptomatic carotid artery disease., Methods: systematic comparison of the 30-day outcome of angioplasty with or without stenting and endarterectomy for symptomatic carotid artery disease reported in single-center studies, published since 1990, was performed., Results: Thirty-three studies (13 angioplasty and 20 carotid endarterectomy) were included in this analysis. Carotid stents were deployed in 44% of angioplasty patients. Mortality within 30 days of angioplasty was 0.8% compared with 1.2% after endarterectomy (OR 0.68, 95% CI 0.43 to 1.05; P=0.6). The stroke rate was 7.1% for angioplasty and 3.3% for endarterectomy (OR 2.22, CI 1.62 to 3.04; P<0.001), while the risk of fatal or disabling stroke was 3.2% and 1.6%, respectively (OR 2.09, CI 1.3 to 3.33; P<0.01). The risk of stroke or death was 7.8% for angioplasty and 4% for endarterectomy (OR 2.02, CI 1.49 to 2.75; P<0.001), while disabling stroke or death was 3.9% after angioplasty and 2.2% after endarterectomy (OR 1.86, CI 1.22 to 2.84; P<0.01)., Conclusions: In the treatment of symptomatic carotid artery disease, the risk of stroke is significantly greater with angioplasty than carotid endarterectomy. At present, carotid angioplasty is not recommended for the majority of patients with symptomatic carotid artery disease.

Background: The natural histories of equally severe symptomatic and asymptomatic carotid stenoses are very different, which suggests dichotomy in plaque behavior. The vascular biology of the symptomatic carotid plaque is presented in this review., Summary of Review: Histology studies comparing asymptomatic and symptomatic plaques were identified from MEDLINE. Reports in which stenosis severity was not stated or not similar for symptomatic and asymptomatic patients were excluded. In vitro studies and reports from the coronary circulation were reviewed with regard to the vascular biology of the plaque. Histology studies comparing carotid plaques removed from symptomatic and asymptomatic patients reveal characteristic features of unstable plaques: surface ulceration and plaque rupture (48% of symptomatic compared with 31% of asymptomatic, P<0.001), thinning of the fibrous cap, and infiltration of the cap by greater numbers of macrophages and T cells. In vitro studies suggest that macrophages and T cells release cytokines and proteinase, which stimulate breakdown of cap collagen and smooth muscle cell apoptosis and thereby promote plaque rupture., Conclusions: Infiltration of inflammatory cells to the surface of carotid plaques may be a critical step in promoting plaque rupture and resultant embolization or carotid occlusion. Further understanding of cell recruitment and behavior in carotid atherosclerosis may allow better detection of unstable plaques and therapeutic methods of plaque stabilization.

Objective: The aim of this study was the definition of the duplex scan parameters that best select patients for carotid endarterectomy., Methods: This study was set in a regional vascular unit. Duplex scanning and angiography were performed prospectively on 50 patients who were symptomatic (100 carotid bifurcation) to identify the most accurate and sensitive duplex scan criteria to identify an 80% to 99% stenosis according to the European Carotid Symptomatic Trial. With data from the European Carotid Symptomatic Trial, we estimated the effect of three different approaches used to select patients for carotid endarterectomy. The first approach was the selection of patients for carotid surgery on the basis of duplex scanning alone with the most accurate duplex scan criteria (approach I). The second approach was the selection of patients for carotid surgery on the basis of duplex scanning alone with a 100% sensitive duplex scan criteria (approach II). The third approach was the selection of patients for angiography with duplex scanning (100% sensitive criteria) and then the use of angiography to define which patients should undergo surgery (approach III)., Results: All three approaches appeared to have a similar potential in stroke reduction. However, approach I, which minimized the number of patients who underwent surgery (19% less than approach II) or invasive imaging (65% less than approach III), appeared to be the most appropriate., Conclusion: These data support the selection of patients for carotid endarterectomy on the basis of duplex scanning alone. The duplex scan criteria should be validated against angiography.

Background: The importance of identifying features of carotid artery disease, in addition to degree of stenosis, which predict subsequent stroke is becoming increasingly clear. This study assessed the relationship between carotid plaque characteristics and presenting symptoms., Methods: Some 285 symptomatic (transient ischaemic attack (TIA) 127, amaurosis fugax 58, transient stroke 15, established stroke 55, progressive stroke 11, crescendo TIA 19) and 65 asymptomatic patients were studied with colour-flow duplex imaging. All patients had 60-99 per cent internal carotid stenosis. Carotid plaque morphology (classified according to Gray-Weale) and plaque surface features were assessed., Results: Plaque types I and II were more common in symptomatic patients (83 per cent versus 44 per cent; P < 0.0001). Plaque surface was classified as smooth (34 per cent), irregular (44 per cent) or ulcerated (22 per cent). Ulceration was also more common in symptomatic patients (23 versus 14 per cent; P = 0.04). In symptomatic patients there was no association between presenting symptom and plaque morphology or surface features (P = 0.9 and P = 0.8 respectively). On multiple regression analysis plaque morphology did not distinguish between patients who presents with stroke without warning and other symptomatic patients (who had TIA, amaurosis fugax, crescendo TIA or stroke with warning)., Conclusion: There was an association between echolucent type I and II carotid plaques and the presence of symptoms but not their type. Plaque morphology was not characteristic in a subgroup of patients who had stroke without warning. Further prospective study of plaque morphology in asymptomatic patients might help identify high-risk groups.

Purpose: This study was performed to determine whether early duplex findings predicted restenosis after carotid endarterectomy., Methods: One hundred ninety-two symptomatic patients who underwent carotid endarterectomy were studied with color duplex imaging at 1 day and 1 week after surgery to identify minor residual disease (causing < 50% stenosis), arterial kinking, and suture stricture, and to measure the external and luminal diameters of the carotid bulb and distal internal carotid artery. Patients were then observed prospectively with duplex surveillance for a median of 24 months to identify > 50% restenosis., Results: Twenty-five stenoses > 50% of the operated carotid artery (13%) were identified, four at 1 day (residual) and 21 at a median follow-up of 6 months (restenosis). On multiple logistic regression analysis, > 50% restenosis was found to be associated with minor day-1 residual stenosis (p = 0.01) and with small luminal diameter of the distal internal carotid artery (p = 0.03) as measured 1 week after carotid endarterectomy. Life table analysis showed restenosis at 24 months to be more common for patients with below-median than patients with above-median carotid bulb external diameter (18% vs 5%, respectively; p = 0.01)., Conclusions: Duplex scanning within a week of carotid endarterectomy identifies > 50% residual stenosis, in addition to minor residual 25% to 50% stenosis and small carotid dimensions, which are good predictors of > 50% restenosis at 6 months.

Purpose: The value of duplex surveillance and the significance of contralateral carotid disease after endarterectomy have been assessed., Methods: Three hundred five patients were observed prospectively after carotid endarterectomy for a median time of 36 months (range, 6 to 96 months), with duplex surveillance performed at 1 day; 1 week; 3, 6, 9, and 12 months; and then each year after endarterectomy., Results: Thirty patients (10%) had ipsilateral symptoms (13 strokes, 17 transient ischemic attacks [TIAs]) at a median time of 6 months (range, 0 to 60 months). Life table analysis demonstrated that ipsilateral stroke was equally common for patients who had > or = 50% restenosis (3% at 36 months) and those who did not (6% at 36 months, p > 0.5). Twenty-three patients (8%) developed symptoms (stroke 5, TIA 14) attributable to the contralateral carotid artery at a median time of 9 months (range, 0 to 36 months) after endarterectomy. By life table analysis, 40% of patients with 70% to 99%, 6% with 50% to 69%, 1% with < 50% contralateral internal carotid stenosis, and 5% with contralateral carotid occlusion at the time of endarterectomy had a contralateral TIA in the 36 months after endarterectomy (p < 0.01). However, contralateral stroke was not significantly more common for patients with severe contralateral internal carotid stenosis demonstrated at the time of endarterectomy (< 50% stenosis, 0%; 50% to 69%, 3%; 70% to 99%, 7%; occlusion, 6% stroke rate at 36 months). Seven of the 32 patients who developed progression of contralateral disease had a TIA, compared with 11 of 227 patients who did not develop progression of contralateral disease (p < 0.01). None of the 12 patients who progressed from a < 70% to a 70% to 99% contralateral stenosis had a stroke., Conclusions: After carotid endarterectomy restenosis is rarely associated with symptoms; contralateral stroke is rare and is not associated with progressive internal carotid artery disease suitable for endarterectomy. This study has shown no benefit from long-term duplex surveillance after carotid endarterectomy. Selective clinical follow-up of patients who have high-grade contralateral stenoses would appear more appropriate.

Purpose: Variability in outcome after carotid endarterectomy is well recognized. This study examines the importance of patient-related factors in determining outcome., Methods: Four hundred and sixty consecutive patients undergoing carotid endarterectomy for symptomatic severe (60% to 99%) internal carotid stenosis performed by one vascular surgeon have been studied prospectively. Patients were followed-up at 3, 6, 9, and 12 months and then yearly. Pre-, intra-, and perioperative details and follow-up information were entered on a database., Results: Multiple logistic regression identified a number of factors significantly associated with death and stroke. A history of crescendo transient ischemic attacks (TIAs) (p = 0.003, p = 0.0002) and being female (p = 0.03, p = 0.0001) were associated with both perioperative death and stroke within 30 days of operation, respectively. Deaths between 1 and 36 months were associated with ischemic heart disease (p = 0.03) and diabetes (p = 0.04), whereas stroke was associated with small internal carotid diameter (p = 0.02). The importance of symptoms at presentation on outcome was further emphasized by life-table analysis. In 98% of patients with amaurosis fugax, only 67% of those with crescendo TIAs were alive at 18 months (p < 0.01). The survival of patients with amaurosis was significantly better than those with TIAs (p < 0.01), transient stroke (p < 0.01), and progressive, stroke (p < 0.05). Similarly, postoperative stroke was significantly more common for patients with crescendo TIAs than those with amaurosis (p < 0.01), established stroke (p < 0.05), and TIA (p < 0.05). Transient stroke was associated with a poor outcome, with only 66% of patients being alive in 36 months and 14% having suffered a stroke (p < 0.05 compared with established stroke)., Conclusion: Presenting symptoms significantly predict outcome after carotid endarterectomy. This should be considered both in patient selection and comparison of patient series.

The quoted combined mortality and morbidity following carotid endarterectomy is about 5-7%. In an attempt to identify a subgroup of high risk patients, a review has been undertaken of 404 carotid endarterectomies performed between January 1985 and March 1994. The perioperative mortality rate was 2%, with 3.4% of patients experiencing transient neurological deficits and 4% permanent strokes. Multiple logistic regression analysis was used to estimate the influence on outcome of age, gender, indication for surgery, bilateral internal carotid artery disease, hypertension and smoking. No significant explanators were identified.

Objectives: Routine patch angioplasty has been advocated following carotid endarterectomy but patching can be associated with complications. This study assesses the effect of a selective patching policy based on distal internal carotid diameter on the rate of restenosis and outcome following carotid endarterectomy., Design, Material and Methods: A consecutive series of 213 patients underwent carotid endarterectomy performed by one surgeon. Preoperative carotid dimensions were measured intraoperatively using calipers. Following endarterectomy a 5mm Dacron patch was selectively employed if the distal internal carotid was 5mm or less (group 1, 95 patients) or 6mm or less (group 2, 118 patients). Patients underwent colour-coded Duplex scanning at 24 h, 1 week, 3, 6, 9, and 12 months, and yearly following this., Results: Overall 27 restenoses (5 residual) of 50% or greater and two occlusions developed. Patching was performed in 47% of group 1 and 61% of group 2 arteries. In group 1 14% of patched compared with 24% of non-patched arteries developed restenosis at 24 months (p=0.4). In group 2 13% of patched compared to 11% of non-patched arteries developed restenosis at 12 months (p>0.5). Stroke rate at 24 months were similar for patched and non-patched patients in groups 1 (p>0.5) and 2 (p=0.4)., Conclusions: This study suggests that patch angioplasty of larger carotid arteries may be unnecessary. Randomisation of larger arteries between patch and primary closure would be required to confirm this.

The recent North American Symptomatic Carotid Endarterectomy Trial has answered fairly conclusively the questions concerning the optimal management of patients with symptoms who have a > 70% stenosis of the internal carotid artery. It has also had the effect of refocusing attention on carotid pathology. The main question still to be answered is whether surgical management is the optimum treatment for other groups of patients with carotid disease. From various studies done on the natural history of carotid plaques it is apparent that there are subgroups who may benefit from surgery, namely those who will progress to stroke if not treated. The problem comes in identifying these subgroups by the factors which cause them to progress. This paper aims to review the role that plaque morphology has in the development of symptoms and whether it should be included with degree of stenosis in assessing the risk of a carotid plaque. The non-invasive assessment of plaque morphology is also reviewed. The evidence from this review does not support the use of plaque morphology as a discriminating factor for carotid endarterectomy at present.