Determination of duplex Doppler ultrasound criteria appropriate to the North American Symptomatic Carotid Endarterectomy Trial

Carotid artery stenting in unfavorable vascular anatomy: Effect of embolic protection filter use on periprocedural complications

OBJECTIVE

To investigate the effect of embolic protection device (EPD) use on periprocedural complications in patients with carotid artery stenosis with anatomical variations.

METHOD

The study retrospectively evaluated 185 patients who consecutively underwent carotid artery stenting between November 2020 and December 2023. Forty-four patients with difficult anatomical structures, anatomical variations in the common carotid artery (CCA) and internal carotid artery (ICA) (tortuosity, kinking, or coiling), and a CCA-ICA angle of >60 degrees were included in the sample. The patients were divided into two groups according to the use of EPD filters during the procedure and compared in terms of periprocedural events.

RESULTS

Of the 44 patients included in the study, 24 (54.5 %) were male, and the mean age of all patients was 68.7 ± 8.7 years. Comorbidities were present in 93.2 % (n = 41) of the patients. The most common comorbidity was hypertension (n = 32, 72.8 %). The CCA-ICA angle was ≥60 degrees in 45.4 % (n = 20) of all patients. ICA tortuosity was detected in 27.2 % (n = 12) of the patients, ICA kinking in 13.6 % (n = 6), ICA coiling in 6.8 % (n = 3), and CCA tortuosity in 6.8 % (n = 3). Procedure-related periprocedural events developed in 38.6 % (n = 17) of the patients. Postprocedural mortality occurred in two patients, secondary to myocardial infarction in one and COVID-19 pneumonia in the other. There was no significant difference between the filter and non-filter groups in relation to periprocedural events (p = 0.638). Major stroke did not occur in either group. Minor neurological events occurred in 15 % (n = 3/20) of the patients in the filter group and 16.7 % (n = 4/24) of those in the non-filter group. The incidence of vasospasm was statistically higher in patients using filters compared to those without filters (30 % vs. 0 %; P = 0.005, respectively).

CONCLUSION

Evaluation of vascular anatomy before carotid artery stenting is important to decide on the technical procedure to be applied in the procedure. The use of EPD in unfavorable anatomy does not reduce periprocedural neurological events. Instead, it results in technical difficulties, prolongs the duration of procedure, and leads to arterial vasospasm. Considering the high periprocedural events in this study, carotid endarterectomy may be a better alternative to endovascular treatment in patients with unfavorable carotid artery anatomy.

Comparative on the effectiveness and safety of different carotid endarterectomy techniques: a single-center Retrospective Study

BACKGROUND

Carotid endarterectomy (CEA) is a surgical procedure that can reduce the risk of stroke in patients with carotid artery stenosis. However, controversy still exists regarding the optimal surgical technique for CEA.

OBJECTIVE

To compare the safety and effectiveness of different techniques.

METHODS

Data on baseline characteristics as well as perioperative and postoperative complications from patients who underwent CEA at the Department of Vascular Surgery, Xuanwu Hospital, Capital Medical University, were retrospectively collected and analyzed.

RESULTS

A total of 262 CEA patients included in study, with a total of 265 CEA operations. The mean age of 69.95 ± 7.29 (range, 44-89) years. 65 (24.5%) patients underwent cCEA, 94 (35.5%) underwent pCEA, and 106 (40.0%) underwent eCEA. The use of shunt (1.9%) and the mean operation time were lower in eCEA group (P < 0.05). eCEA was also associated with a lower incidence of postoperative hypotension, whereas pCEA was associated with a lower incidence of postoperative hypertension (P < 0.05). There was no significant difference in clinical baseline characteristics, occurrence of perioperative complications, and survival whether restenosis-free, asymptomatic or overall.

CONCLUSIONS

This study found that all three surgical methods are equally safe for the treatment of carotid artery stenosis and are effective in preventing stroke.

Comparison Between Conventional and Patch Carotid Endarterectomy: A Single-Center Retrospective Study

OBJECTIVE

To compare perioperative and long-term safety and effectiveness between conventional carotid endarterectomy (cCEA) and patch carotid endarterectomy (pCEA) under current medical conditions.

METHODS

Data on baseline characteristics as well as perioperative and long-term postoperative complications from patients who underwent cCEA or pCEA at the Department of Vascular Surgery, Xuanwu Hospital of Capital Medical University, from 2013 to 2022, were retrospectively collected and analyzed.

RESULTS

A total of 248 CEA patients were included in our study. The majority of patients (87.3%) were male, and mean age was 63.6 ± 7.6 (range, 40-81) years; 104 patients (41.9%) underwent cCEA, while 144 (58.1%) underwent pCEA. Between the cCEA and pCEA groups, there were no significant differences in clinical baseline characteristics, occurrence of perioperative or long-term (median, 42.5 [range, 7 to 120] months) complications, and survival whether restenosis-free, asymptomatic or overall.

CONCLUSIONS

In a single-center experience, conventional and patch CEA approaches appear similarly safe and effective.

Quantifying Carotid Stenosis: History, Current Applications, Limitations, and Potential: How Imaging Is Changing the Scenario

Carotid artery stenosis is a major cause of morbidity and mortality. The journey to understanding carotid disease has developed over time and radiology has a pivotal role in diagnosis, risk stratification and therapeutic management. This paper reviews the history of diagnostic imaging in carotid disease, its evolution towards its current applications in the clinical and research fields, and the potential of new technologies to aid clinicians in identifying the disease and tailoring medical and surgical treatment.

Accuracy of the Society of Radiologists in Ultrasound (SRU) Carotid Doppler Velocity Criteria for Grading North American Symptomatic Carotid Endarterectomy Trial (NASCET) Stenosis: A Meta-Analysis

PURPOSE

The Society of Radiologists in Ultrasound (SRU) consensus panel proposed six Doppler velocity cut points for classifying internal carotid artery (ICA) stenosis of 50% and 70% according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method. Their relative accuracies have not been compared.

MATERIALS AND METHODS

Meta-analysis performed following comprehensive literature review and identification of manuscripts with graphs of individual patient NASCET ICA stenosis measured by arteriography versus ICA peak-systolic velocity (PSV), end-diastolic velocity (EDV) and ICA PSV to common carotid artery (CCA) PSV. True positives, true negatives, false positives, and false negatives were calculated and used in two-level mixed effects models. Hierarchical summary receiver operating characteristic (ROC) curves were generated. Areas under the ROC curves were estimated.

RESULTS

Nine studies performed between 1993 and 2016 were identified after review of 337 manuscripts. There were 1738 bifurcation data points extracted for PSV, 1026 for EDV, and 775 for ICA/CCA ratio. The highest sensitivity was 96% (95% CI: 93%, 98%) for PSV of 125 cm/s (50% stenosis) and highest specificity 86% (95% CI: 71%, 93%) for PSV of 230 cm/s (70% stenosis). Areas under the ROC curves ranged from a high of 0.93 (95% CI: 0.92, 0.95) for PSV (50% stenosis) to a low of 0.86 (95% CI: 0.84, 0.88) for EDV (70% stenosis).

CONCLUSIONS

The SRU consensus Doppler cut points vary in their accuracies for predicting ICA stenosis. The PSV cut points have tradeoffs: high sensitivity/low specificity for 50% stenosis and high specificity/moderate sensitivity for 70% stenosis.

Utility of carotid ultrasound on prediction of 1-year mortality in emergency department patients with neurological deficits: A 10-year population-based cohort study

BACKGROUND

This study aimed to investigate the association between the carotid ultrasound results and 1-yr mortality of patients with neurological deficits in the emergency department (ED).

METHODS

This study included patients with neurological symptoms who presented to the ED between January 1, 2009 and December 31, 2018, and underwent sonographic imaging of the bilateral carotid bulb, common carotid artery (CCA), internal carotid artery (ICA), and external carotid arteries. A stenosis degree of >50% was defined as significant carotid stenosis. Carotid plaque score (CPS) was calculated by adding the score of stenosis severity of all segments. The association between carotid ultrasound results and 1-yr mortality was investigated using the Cox regression model.

RESULTS

The analysis included 7,961 patients (median age: 69 yr; men: 58.7%). Among them, 247 (3.1%) passed away from cardiovascular (CV)-related causes, and 746 (9.4%) died within a year. The mortality group presented with more significant carotid stenosis of the carotid bulb, CCA, or ICA and had a higher median CPS. A higher CPS was associated with a greater 1-yr all-cause mortality (adjusted hazard ratio [aHR] = 1.08; 95% confidence interval [CI] = 1.03-1.13; p = 0.001; log-rank p < 0.001) and CV-related mortality (aHR = 1.13; 95% CI = 1.04-1.22; p = 0.002, log-rank p < 0.001). Significant stenosis of either carotid artery segment did not result in a higher risk of 1-yr mortality.

CONCLUSIONS

We comprehensively investigated the utility of carotid ultrasound parameters on predicting mortality in this 10-yr population-based cohort, which included over 7,000 patients with acute neurological deficits presented to the ED. The result showed that CPS could be used as risk stratification tools for 1-yr all-cause and CV mortality.

Bedside Cerebral Blood Flow Quantification in Neonates

Measurement of blood flow to the brain in neonates would be a very valuable addition to the medical diagnostic armamentarium. Such conditions such as assessment of closure of a patent ductus arteriosus (PDA) would greatly benefit from such an evaluation. However, measurement of cerebral blood flow in a clinical setting has proven very difficult and, as such, is rarely employed. Present techniques are often cumbersome, difficult to perform and potentially dangerous for very low birth weight (VLBW) infants. We have been developing an ultrasound blood volume flow technique that could be routinely used to assess blood flow to the brain in neonates. By scanning through the anterior fontanelles of 10 normal, full-term newborn infants, we were able to estimate total brain blood flows that closely match those published in the literature using much more invasive and technically demanding methods. Our method is safe, easy to do, does not require contrast agents and can be performed in the baby's incubator. The method has the potential for monitoring and assessing blood flows to the brain and could be used to routinely assess cerebral blood flow in many different clinical conditions.

Duplex ultrasound for diagnosing symptomatic carotid stenosis in the extracranial segments

BACKGROUND

Carotid artery stenosis is an important cause of stroke and transient ischemic attack. Correctly and rapidly identifying patients with symptomatic carotid artery stenosis is essential for adequate treatment with early cerebral revascularization. Doubts about the diagnostic value regarding the accuracy of duplex ultrasound (DUS) and the possibility of using DUS as the single diagnostic test before carotid revascularization are still debated.

OBJECTIVES

To estimate the accuracy of DUS in individuals with symptomatic carotid stenosis verified by either digital subtraction angiography (DSA), computed tomography angiography (CTA), or magnetic resonance angiography (MRA).

SEARCH METHODS

We searched CRDTAS, CENTRAL, MEDLINE (Ovid), Embase (Ovid), ISI Web of Science, HTA, DARE, and LILACS up to 15 February 2021. We handsearched the reference lists of all included studies and other relevant publications and contacted experts in the field to identify additional studies or unpublished data.

SELECTION CRITERIA

We included studies assessing DUS accuracy against an acceptable reference standard (DSA, MRA, or CTA) in symptomatic patients. We considered the classification of carotid stenosis with DUS defined with validated duplex velocity criteria, and the NASCET criteria for carotid stenosis measures on DSA, MRA, and CTA. We excluded studies that included < 70% of symptomatic patients; the time between the index test and the reference standard was longer than four weeks or not described, or that presented no objective criteria to estimate carotid stenosis.

DATA COLLECTION AND ANALYSIS

The review authors independently screened articles, extracted data, and assessed the risk of bias and applicability concerns using the QUADAS-2 domain list. We extracted data with an effort to complete a 2 × 2 table (true positives, true negatives, false positives, and false negatives) for each of the different categories of carotid stenosis and reference standards. We produced forest plots and summary receiver operating characteristic (ROC) plots to summarize the data. Where meta-analysis was possible, we used a bivariate meta-analysis model.

MAIN RESULTS

We identified 25,087 unique studies, of which 22 were deemed eligible for inclusion (4957 carotid arteries). The risk of bias varied considerably across the studies, and studies were generally of moderate to low quality. We narratively described the results without meta-analysis in seven studies in which the criteria used to determine stenosis were too different from the duplex velocity criteria proposed in our protocol or studies that provided insufficient data to complete a 2 × 2 table for at least in one category of stenosis. Nine studies (2770 carotid arteries) presented DUS versus DSA results for 70% to 99% carotid artery stenosis, and two (685 carotid arteries) presented results from DUS versus CTA in this category. Seven studies presented results for occlusion with DSA as the reference standard and three with CTA as the reference standard. Five studies compared DUS versus DSA for 50% to 99% carotid artery stenosis. Only one study presented results from 50% to 69% carotid artery stenosis. For DUS versus DSA, for < 50% carotid artery stenosis, the summary sensitivity was 0.63 (95% confidence interval [CI] 0.48 to 0.76) and the summary specificity was 0.99 (95% CI 0.96 to 0.99); for the 50% to 69% range, only one study was included and meta-analysis not performed; for the 50% to 99% range, the summary sensitivity was 0.97 (95% CI 0.95 to 0.98) and the summary specificity was 0.70 (95% CI 0.67 to 0.73); for the 70% to 99% range, the summary sensitivity was 0.85 (95% CI 0.77 to 0.91) and the summary specificity was 0.98 (95% CI 0.74 to 0.90); for occlusion, the summary sensitivity was 0.91 (95% CI 0.81 to 0.97) and the summary specificity was 0.95 (95% CI 0.76 to 0.99). For sensitivity analyses, excluding studies in which participants were selected based on the presence of occlusion on DUS had an impact on specificity: 0.98 (95% CI 0.97 to 0.99). For DUS versus CTA, we found two studies in the range of 70% to 99%; the sensitivity varied from 0.57 to 0.94 and the specificity varied from 0.87 to 0.98. For occlusion, the summary sensitivity was 0.95 (95% CI 0.80 to 0.99) and the summary specificity was 0.91 (95% CI 0.09 to 0.99). For DUS versus MRA, there was one study with results for 50% to 99% carotid artery stenosis, with a sensitivity of 0.88 (95% CI 0.70 to 0.98) and specificity of 0.60 (95% CI 0.15 to 0.95); in the 70% to 99% range, two studies were included, with sensitivity that varied from 0.54 to 0.99 and specificity that varied from 0.78 to 0.89. We could perform only a few of the proposed sensitivity analyses because of the small number of studies included.

AUTHORS' CONCLUSIONS

This review provides evidence that the diagnostic accuracy of DUS is high, especially at discriminating between the presence or absence of significant carotid artery stenosis (< 50% or 50% to 99%). This evidence, plus its less invasive nature, supports the early use of DUS for the detection of carotid artery stenosis. The accuracy for 70% to 99% carotid artery stenosis and occlusion is high. Clinicians should exercise caution when using DUS as the single preoperative diagnostic method, and the limitations should be considered. There was little evidence of the accuracy of DUS when compared with CTA or MRA. The results of this review should be interpreted with caution because they are based on studies of low methodological quality, mainly due to the patient selection method. Methodological problems in participant inclusion criteria from the studies discussed above apparently influenced an overestimated estimate of prevalence values. Most of the studies included failed to precisely describe inclusion criteria and previous testing. Future diagnostic accuracy studies should include direct comparisons of the various modalities of diagnostic tests (mainly DUS, CTA, and MRA) for carotid artery stenosis since DSA is no longer considered to be the best method for diagnosing carotid stenosis and less invasive tests are now used as reference standards in clinical practice. Also, for future studies, the participant inclusion criteria require careful attention.

Quantification and mapping of cerebral hemodynamics before and after carotid endarterectomy, using four-dimensional flow magnetic resonance imaging

BACKGROUND

Carotid stenosis can profoundly affect cerebral hemodynamics, which cannot simply be inferred from the degree of stenosis. We quantified and mapped the distribution of the blood flow rate (BFR) in the cerebral arteries before and after carotid endarterectomy using four-dimensional (4D) phase-contrast (PC) magnetic resonance imaging (MRI).

METHODS

Nineteen patients (age, 71 ± 6 years; 2 women) with symptomatic carotid stenosis (≥50%) undergoing carotid endarterectomy (CEA) were investigated using 4D PC-MRI before and after surgery. The BFR was measured in 17 cerebral arteries and the ophthalmic arteries. Collateral recruitment through the anterior and posterior communicating arteries, ophthalmic arteries, and leptomeningeal arteries was quantified. BFR laterality was significantly different between the paired contralateral and ipsilateral arteries. Subgroups were defined according to the presence of collateral recruitment.

RESULTS

The total cerebral blood flow had increased by 15% (P < .01) after CEA. Before CEA, laterality was seen in the internal carotid artery, anterior cerebral artery, and middle cerebral artery (MCA). On the ipsilateral side, an increased BFR was found after CEA in the internal carotid artery (246 ± 62 mL/min vs 135 ± 80 mL/min; P < .001), anterior cerebral artery (87 ± mL/min vs 38 ± 58 mL/min; P < .01), and MCA (149 ± 43 mL/min vs 119 ± 34 mL/min; P < .01), resulting in a postoperative BFR distribution without signs of laterality. In the nine patients with preoperatively recruited collaterals, BFR laterality was found in the MCA before, but not after, CEA (P < .01). This laterality was not found in the 10 patients without collateral recruitment (P = .2). The degree of stenosis did not differ between the groups with and without collateral recruitment (P = .85).

CONCLUSIONS

Using 4D PC-MRI, we have presented a comprehensive and noninvasive method to evaluate the cerebral hemodynamics due to carotid stenosis before and after CEA. MCA laterality, seen in the patients with collateral recruitment before CEA, pointed toward a hemodynamic disturbance in MCA territory for those patients. This methodologic advancement provides an insight into the pathophysiology of cerebral hemodynamics in patients with carotid stenosis.

Ultrasound Assessment of Extracranial Carotids and Vertebral Arteries in Acute Cerebral Ischemia

Assessing ischemic etiology and mechanism during the acute phase of an ischemic stroke is crucial in order to tailor and monitor appropriate treatment and determine prognosis. Cervical Duplex Ultrasound (CDU) has evolved since many years as an excellent screening tool for the evaluation of extracranial vasculature. CDU has the advantages of a low cost, easily applicable, bed side examination with high temporal and spatial resolution and without exposing the patients to any significant complications. It represents an easily repeatable test that can be performed in the emergency room as a first-line examination of cervical artery pathology. CDU provides well validated estimates of the type of the atherosclerotic plaque, the degree of stenosis, as well as structural and hemodynamic information directly about extracranial vessels (e.g., subclavian steal syndrome) and indirectly about intracranial circulation. CDU may also aid the diagnosis of non-atherosclerotic lesions of vessel walls including dissections, arteritis, carotid-jugular fistulas and fibromuscular dysplasias. The present narrative review outlines all potential applications of CDU in acute stroke management and also highlights its potential therapeutic implications.

The management of carotid restenosis: a comprehensive review

Carotid artery stenosis (CS) is a major medical problem affecting approximately 10% of the general population 80 years or older and causes stroke in approximately 10% of all ischemic events. In patients with symptomatic, moderate-to-severe CS, carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS), has been used to lower the risk of stroke. In primary CS, CEA was found to be superior to best medical therapy (BMT) according to 3 large randomized controlled trials (RCT). Following CEA and CAS, restenosis remains an unsolved problem involving a large number of patients as the current treatment recommendations are not as clear as those for primary stenosis. Several studies have evaluated the risk of restenosis, reporting an incidence ranging from 5% to 22% after CEA and an in-stent restenosis (ISR) rate ranging from 2.7% to 33%. Treatment and optimal management of this disease process, however, is a matter of ongoing debate, and, given the dearth of level 1evidence for the management of these conditions, the relevant guidelines lack clarity. Moreover, the incidence rates of stroke and complications in patients with carotid stenosis are derived from studies that did not use contemporary techniques and materials. Rapidly changing guidelines, updated techniques, and materials, and modern medical treatments make actual incidence rates barely comparable to previous ones. For these reasons, RCTs are critical for determining whether these patients should be treated with more aggressive treatments additional to BMT and identifying those patients indicated for surgical or endovascular treatments. This review summarizes the current evidence and controversies concerning the risks, causes, current treatment options, and prognoses in patients with restenosis after CEA or CAS.

Autodetect extracranial and intracranial artery stenosis by machine learning using ultrasound

BACKGROUND

and Purpose: This study proposed a machine learning method for identifying ≥50% stenosis of the extracranial and intracranial arteries.

PATIENTS AND METHODS

A total of 8211 patients with both carotid ultrasound and cerebral angiography were enrolled. Support vector machine (SVM) was employed as the machine learning classifier. Carotid Doppler parameters and transcranial Doppler parameters were used as the input features. Feature selection was performed using the Extra-Trees (extremely randomized trees) method.

RESULTS

For the machine learning method, the sensitivities and specificities of identifying stenosis of the extracranial arteries were 88.5%-100% and 96.0%-100%, respectively. The sensitivities and specificities of identifying stenosis of the intracranial arteries were 71.7%-100% and 88.9%-100%, respectively.

CONCLUSIONS

The SVM classifier with feature selection is an efficient method for identifying the stenosis of both intracranial and extracranial arteries. Comparing with traditional Doppler criteria, this machine learning method achieves up to 20% higher in accuracy and 45% in sensitivity, respectively.

Is Radiation a Risk Factor for Atherosclerosis? An Echo-Color Doppler Study on Hodgkin and Non-Hodgkin Patients

Aims and background

The aim of the present paper was to study the role of irradiation in the atherosclerotic process in patients affected by Hodgkin and non-Hodgkin lymphoma.

Methods

We studied 84 subjects, 42 with Hodgkin or non-Hodgkin disease and 42 controls. All 42 cases had been irradiated and were comparable in terms of risk factors for atherosclerosis. All 84 subjects underwent echo-color Doppler of the arterial axis (carotids, abdominal aorta, and femoral arteries), and the intima-media thickness was measured.

Results

The irradiated cases had a greater intima-media thickness in the carotid district, even after dividing them according to age and sex; males were affected more than females. The irradiated patients were at greater risk of developing cardiovascular events than the controls.

Conclusions

An echo-color Doppler of the carotid district is advisable in all patients who have been submitted to radiotherapy, and the patients with a significantly greater than normal intima-media thickness need a strict follow-up, and antioxidant or antiaggregant therapy should be considered.

Circulating miRNA levels differ with respect to carotid plaque characteristics and symptom occurrence in patients with carotid artery stenosis and provide information on future cardiovascular events

Introduction

Circulating microRNAs (miRNAs) levels are potentially important biomarkers and therapeutic targets of cerebral ischemic event (CIE) in patients with internal carotid artery stenosis (ICAS).

Aim

This prospective study investigated associations between circulating miRNAs and symptomatic and asymptomatic ICAS, carotid plaque morphology and future cardiovascular events.

Material and methods

Circulating miRNAs (miR-1-3p, miR-16-5p, miR-34a-5p, miR-124-3p, miR-133a-3p, miR-133b, miR-134-5p, miR-208b-3p, miR-375 and miR-499-5p) were analyzed in 92 consecutive patients with significant ICAS referred for revascularization. Group I comprised 65 subjects (41 males, age 69.3 ±9.7 years) with a recent CIE. Group II comprised 27 patients (15 males, age 68.2 ±8.4 years) with asymptomatic ICAS. The ICAS degree and plaque morphology was assessed by ultrasonography. The incidences of cardiovascular death (CVD), myocardial infarction (MI) and recurrent CIE (CVD/MI/CIE) were recorded prospectively (mean: 38.7 ±3.8 months).

Results

Groups II and I differed significantly in levels of miR-124-3p (p = 0.036), miR-133a-3p (p = 0.043) and miR-134-5p (p = 0.02). Hypoechogenic, as compared to echogenic, plaques differed in levels of miR-124-3p (p = 0.038), miR-34a-5p (p = 0.006), miR-133b (p = 0.048), miR-134-5p (p = 0.045), and miR-375 (p = 0.016), while calcified plaques differed in miR-16-5p (p = 0.023). Ulcerated plaques showed higher levels of miR-1-3p (p = 0.04) and miR-16-5p (p = 0.003), while thrombotic plaques showed lower levels of miR-1-3p (p = 0.032). CVD/MI/CIE occurred in 14 (15.5%) out of 90 follow-up patients. Multivariate Cox and ROC analysis showed associations between miR-1-3p and CVD (AUC = 0.634; HR = 4.84; 95% CI: 1.62–14.5; p = 0.005), MI (AUC = 0.743; HR = 7.8; 95% CI: 2.01–30.0; p = 0.003), and CVD/MI/CIE (AUC = 0.560; HR = 4.6; 95% CI: 1.61–13.1; p = 0.004), while miR-133b was associated with recurrent CIE (AUC = 0.581; HR = 2.25; 95% CI: 1.01–5.02; p = 0.047).

Conclusions

A significant difference in levels of selected miRNAs is observed in symptomatic vs. asymptomatic ICAS. Plaque morphology and structure is associated with change of miRNA levels. The expression of miR-1-3p may be a potential prognostic factor for future cardiovascular events.

Magnetic resonance imaging and clinical outcome in patients with symptomatic carotid artery stenosis after carotid artery revascularization

Introduction

About 30% of patients with carotid artery stenosis (CAS) develop dementia after a cerebral ischemic event (CIE), and 20–50% suffer from CIE recurrence during 6 months. Carotid artery revascularization (CAR) may prevent CIE recurrence, at the cost of new microembolic lesions (MES). The impact of CAR on cognitive function is debatable.

Aim

To assess functional and cognitive outcome, cerebral flow on transcranial Doppler (TCD) and brain magnetic resonance imaging (MRI) in patients with symptomatic CAS referred for CAR.

Material and methods

Twenty-two patients (aged 69.0 ±7.2 y.o., 15 male) with recent CIE (21.9 ±20.9 days to CAR) related to CAS of mean 89.8 ±3.9% lumen reduction were prospectively evaluated with TCD, diffusion and perfusion MRI, Montreal Cognitive Assessment (MoCA), Mini Mental State Examination (MMSE), modified Rankin Scale (mRS) and the National Institutes of Health Stroke Scale (NIHSS) 24 h before, at 24–48 h and 1 month following CAR.

Results

New MES were found in 11 (50%) subjects following CAR. CAR resulted in a significant increase of cerebral flow velocity in the middle and anterior cerebral arteries (p < 0.002 and p = 0.003; respectively) and cerebral perfusion measured by time to peak (TTP) and mean transit time (MTT) (p = 0.0009 and p = 0.0002; respectively). Neurologic tests showed improvement in NIHSS (2.4 ±1.6 to 1.5 ±1.2, p = 0.003), mRS (from 1.3 ±0.9 to 0.7 ±0.9, p = 0.005), and MMSE (26.7 ±2.2 to 27.6 ±2.3, p = 0.019) at 1 month, while similar MoCA scores were observed before and 1 month after CAR (23.4 ±3.3 vs. 24.1 ±3.7, p = 0.136).

Conclusions

Improvement of cerebral flow and perfusion and functional outcome, as well as at least no cognitive decline, is observed after CAR for symptomatic CAS.

Grading of proximal internal carotid artery (ICA) stenosis by Doppler/duplex ultrasound (DUS) and computed tomographic angiography (CTA): correlation and interrater reliability in real-life practice

Doppler/duplex ultrasound (DUS) and computed tomographic angiography (CTA) are frequently applied methods to assess the degree of proximal internal carotid artery (ICA) stenoses in patients with acute ischemic stroke. This study evaluated the agreement and interrater reliability (IR) of both methods using a revised DUS grading system as well as different criteria (ECST/NASCET) under real-life conditions. CTA and DUS data of 281 proximal ICA stenoses [143 patients; 65.7 % male; age (mean (years) ± SD, range) 72.2 ± 11.1, 40-99] were retrospectively analyzed. For both methods, two independent raters estimated the degree of stenosis according to NASCET and ECST criteria. DUS raters applied revised German DUS criteria. For agreement and IR assessment, the linear weighted Kappa statistic was used. Correlation between DUS and CTA was substantial irrespective of the applied classification [weighted Kappa: 0.77 (NASCET)/0.79 (ECST)]. IR for DUS was almost perfect (weighted Kappa: 0.94) and better than for CTA [weighted Kappa: 0.78 (NASCET)/0.78 (ECST)]. In a real-life setting, CTA and DUS assessments of the degree of proximal ICA stenoses agreed substantially irrespective of the criteria applied (ECST/NASCET). For DUS, IR was better than for CTA.

Type IIB von Willebrand Disease: Role of Qualitative Defects in Atherosclerosis and Endothelial Dysfunction

Objective. To verify whether a hereditary bleeding tendency, such as von Willebrand disease (vWD) type IIB, protects against the onset of atherosclerosis. Participants and Methods. Twenty-four patients with vWD type IIB and 24 healthy controls, matched for common atherosclerotic risk factors. All patients were evaluated by color Doppler ultrasound of the common carotid, carotid bifurcation, common femoral artery, brachial artery, and abdominal aorta, investigating intima-media thickness (IMT) and presence of plaques in each arterial district. Flow mediated dilation (FMD) of the brachial artery was used to test endothelial function. Results. vWD type IIB patients presented no significant difference in IMT in any arterial district. FMD showed no differences between the 2 groups. Conclusions. The quantitative clotting defect characteristic of vWD type IIB does not seem to protect against atherosclerosis.

Screening Algorithm for Aortoiliac Occlusive Disease Using Duplex Ultrasonography–Acquired Velocity Spectra from the Distal External Iliac Artery

Aortoiliac duplex scanning can be difficult to perform owing to the deep location of these vessels. We propose a new method to indirectly screen for aortoiliac disease by performing duplex examination of the distal external iliac artery (DEIA). After performing a preliminary study on 21 patients, the parameters of the Doppler waveform that best distinguish normal from diseased arteries were the presence or absence of reverse flow, peak systolic velocity, and resistance index. These values were used in a derived equation, with the value Y ≥ 0.78 predicting normal proximal inflow. We then studied 118 aortoiliac segments in 81 consecutive patients with arteriography and DEIA duplex ultrasonography. To predict moderate to severe stenosis, duplex ultrasonography had a sensitivity of 95.7%, a specificity of 84.1%, a positive predictive value of 80%, and a negative predictive value of 96.8%. Our formula thus predicted significant disease in 55 of the 118 aortoiliac segments (47%), with these segments needing further arteriographic evaluation. The other 63 limbs can be safely considered as having normal aortoiliac inflow.

Our method accurately screens for aortoiliac disease and is excellent for predicting normal inflow. This information can be used to better plan the intraoperative diagnostic study and intervention.

Cranial nerve injury is associated with dual antiplatelet therapy use and cervical hematoma after carotid endarterectomy

OBJECTIVE

To determine predictors of cranial nerve injury (CNI) after carotid endarterectomy (CEA).

METHODS

Consecutive CEAs performed over a 5-year period were enrolled in this study. Outcomes analyzed included 30-day major adverse event rate (composite of stroke, death, and myocardial infarction), death, stroke, disabling stroke, myocardial infarction, cervical hematoma and CNI rate, reoperation, and hospital readmission at 30 days.

RESULTS

There were 1258 CEAs were included in the study, 1168 (93%) were performed using an eversion technique. Patients with symptoms comprised 27% of the cohort (n = 340). At 30 days, there were no deaths, 23 major adverse events (1.8%), 11 strokes (0.9%: nine minor, two major), 12 myocardial infarctions (0.9%), 41 cervical hematomas (3.3%), 9 reoperations (0.7%) and 10 hospital readmissions (0.8%). Median duration of stay was 1 day (interquartile range, 1-2 days). CNI rate at discharge was 2.3% (n = 29). Two patients (9%) had more than one cranial nerve affected. The marginal mandibular branch of the facial nerve was most frequently involved (n = 16; 52%), followed by the hypoglossal (n = 9; 29%), the vagus (n = 4; 13%), and the spinal accessory nerve (n = 2; 6%). Horner's syndrome, consistent with an injury to the cervical sympathetic chain, occurred in 13 patients (1%) who had a true cranial nerve affected as well. The vast majority (94%) of these CNIs and all Horner's syndrome neurapraxias were transient; only the two accessory lesions persisted at their follow-up visit (median, 32 months; range, 8-72 months). Significant predictors for CNI included diabetes (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.0-6.2; P = .048), cervical hematoma (OR, 41.7; 95% CI, 13.8-125.4; P < .001), and dual antiplatelet therapy (OR, 4.4; 95% CI, 1.7-11.4; P = .002).

CONCLUSIONS

CNI is predominantly a transient complication, but is associated significantly with dual antiplatelet therapy use and the occurrence of a postoperative cervical hematoma. Scrupulous attention to hemostasis might reduce the incidence of CNI.

Computer-Vision-Guided Human Pulse Rate Estimation: A Review

Human pulse rate (PR) can be estimated in several ways, including measurement instruments that directly count the PR through contact- and noncontact-based approaches. Over the last decade, computer-vision-assisted noncontact-based PR estimation has evolved significantly. Such techniques can be adopted for clinical purposes to mitigate some of the limitations of contact-based techniques. However, existing vision-guided noncontact-based techniques have not been benchmarked with respect to a challenging dataset. In view of this, we present a systematic review of such techniques implemented over a uniform computing platform. We have simultaneously recorded the PR and video of 14 volunteers. Five sets of data have been recorded for every volunteer using five different experimental conditions by varying the distance from the camera and illumination condition. Pros and cons of the existing noncontact image- and video-based PR techniques have been discussed with respect to our dataset. Experimental evaluation suggests that image- or video-based PR estimation can be highly effective for nonclinical purposes, and some of these approaches are very promising toward developing clinical applications. The present review is the first in this field of contactless vision-guided PR estimation research.

Low prevalence of collateral cerebral circulation in the circle of Willis in patients with severe carotid artery stenosis and recent ischemic stroke

INTRODUCTION

The circle of Willis is thought to play a key role in development of collateral flow in patients with internal carotid artery stenosis (ICAS).

AIM

To assess flow in the circle of Willis in patients with recent ischemic stroke (IS).

MATERIAL AND METHODS

The study included 371 patients, 102 symptomatic with severe ICAS and recent IS (within the last 3 months) (group I) and 269 asymptomatic with severe ICAS (group II). Flow in the middle (MCA), anterior (ACA) and posterior (PCA) cerebral arteries and pattern of the cross-flow through anterior (ACoA) and posterior (PCoA) communicating arteries were assessed with transcranial color-coded Doppler ultrasonography (TCCD).

RESULTS

The ACoA or PCoA was less prevalent in group I than in group II (54% vs. 78%, p < 0.001 and 20% vs. 42%, p < 0.001, respectively), resulting in lower peak-systolic velocity (PSV) in the MCA in group I vs. group II (p = 0.015). Any collateral pathway was present in 67% of patients in group I, compared to 86% in group II (p < 0.001). Both PSV and end-diastolic (EDV) flow velocity in the ACA were lower in patients with recent IS, compared to asymptomatic subjects (71 ±24 cm/s vs. 86 ±34 cm/s, p < 0.001 and 32 ±12 cm/s vs. 37 ±17 cm/s, p = 0.038, respectively). Presence of ACoA or PCoA and higher PSV in the MCA and ACA were associated with significant risk reduction of IS (RR = 0.28 (95% CI = 0.16-0.49, p < 0.001), RR = 0.28 (95% CI = 0.15-0.52, p < 0.001), RR = 0.97 (95% CI = 0.96-0.99, p < 0.001), RR = 0.99 (95% CI = 0.98-0.99, p < 0.032), respectively). However, ROC curves failed to show reliable MCA or ACA PSV cut-offs for IS risk assessment.

CONCLUSIONS

The ACoA and PCoA seem to play a key role in the evaluation of IS risk in subjects with severe ICAS.

Outcome of carotid angioplasty with a novel open-cell carotid stent system

BACKGROUND

The choice of carotid stent systems depends primarily on the anatomy of the carotid artery, the lesion morphology, and the patient's risk factors. Design improvements in devices, in terms of crossing profile and the ability to precisely position the stent, may greatly contribute to the procedural success without compromising acute clinical outcomes.

METHODS AND RESULTS

The primary objective of this clinical registry was to evaluate the early safety and efficacy of a novel open-cell carotid stent system in an "all comer" population suitable for carotid artery stenting. The primary end point was the composite of ipsilateral stroke and "all-cause mortality" within 30 days after the procedure. Secondary end points entailed the rates of myocardial infarction and other clinical complications within the first 30 days following the procedure and up to the 6-month follow-up. Unsuccessful placement and/or withdrawal of the delivery system, as well as device-related complications involving the carotid artery and the rate of nonlesion-related embolisms, were evaluated relative to other currently available carotid stents. The 30-day composite death/stroke rate was 2.8% (3 of 106) while the overall stent system performance was similar to commonly used carotid stent systems.

CONCLUSIONS

The utilized open-cell carotid stent system had favorable lesion crossing and positioning characteristics without compromising the 30-day composite death/stroke rate.

Comparison of Doppler ultrasound velocity parameters in the determination of internal carotid artery stenosis

This study aims to compare the evidence base and practical results of the Joint Recommendations for Reporting Carotid Ultrasound Investigations in UK, published in 2009, and existing carotid scan protocols based on the Society of Radiologists in Ultrasound 2003 Consensus. A prospective sequential evaluation of the 2009 recommendations was performed at the University Hospital of Wales, Cardiff. Additional measurements in line with the recommendations were made during carotid scans. The grading of internal carotid artery stenosis using the 2003 and 2009 UK recommendations, and recommended measures of PSV, PSV ratio and St Mary’s ratio were compared. In comparison to PSV classification, PSV ratio produced lower stenosis classification in 29% and 24% of cases in the 50–69% and 70–89% stenosis bands respectively. St Mary’s ratio produced poor classification agreement across all bands, particularly the 50%–69% stenosis band. Agreement of two measures is recommended for diagnostic confidence; however, in the 50%–69% and 70%–89% stenosis bands, agreement of two measures only occurred in 70% of scans. This evaluation suggests that the use of three measurements in the 2009 recommendations complicates rather than aids diagnosis, especially in the 50%–69% and 70%–89% stenosis bands, and does not provide significant improvement over the 2003 guidelines. No evidence was found to support the combined use of the three measures.

Color duplex sonography in the detection of internal carotid artery restenosis after carotid endarterectomy: comparison with computed tomographic angiography

OBJECTIVES

Internal carotid artery restenosis after carotid endarterectomy is a major postoperative event, but the clinically best suited means for diagnosis of restenosis are still debated. The objective of this study was to evaluate the sensitivity and specificity of color duplex sonography for detection of substantial internal carotid artery restenosis, verified by computed tomographic (CT) angiography.

METHODS

The study group consisted of 210 consecutive patients with internal carotid artery restenosis, defined as restenosis of 50% or greater, verified by color duplex sonography. The degree of restenosis was calculated according to the European Carotid Surgery Trial guidelines. All patients underwent CT angiography. The specificity, sensitivity, positive predictive value, and negative predictive value of color duplex sonography were calculated.

RESULTS

In 85 patients, internal carotid artery restenosis on color duplex sonography was 50% to 69%, whereas in 125 patients it was 70% or greater. When color duplex sonography was compared with CT angiography, only 2 patients in the group with restenosis of 50% to 69% were misclassified by color duplex sonography, in whom CT angiography showed stenosis of 70% or greater. No patient with stenosis of 70% or greater on color duplex sonography was shown to have a lesser degree of restenosis on CT angiography. When compared with CT angiography, color duplex sonography had specificity of 97.7%, sensitivity of 100%, a positive predictive value of 98.4%, and a negative predictive value of 100% for the detection of internal carotid artery restenosis.

CONCLUSIONS

Color duplex sonography can be effectively used as a primary diagnostic tool for evaluation of patients with suspected internal carotid artery restenosis after carotid endarterectomy.

Clinical course of asymptomatic patients with carotid duplex scan end diastolic velocities of 100 to 124 centimeters per second

OBJECTIVE

With the decline of diagnostic angiography, clinicians increasingly rely upon duplex scan criteria to select appropriate asymptomatic candidates for carotid intervention. Some recent trials have enrolled patients for intervention based upon end diastolic velocities (EDVs) as low as 100 cm/second, and peak systolic velocities (PSVs) as low as 230 cm/second. In as much as we have used more selective duplex scan criteria, we reviewed the course of asymptomatic patients who had EDVs from 100 to 124 cm/second.

METHODS

Of the patients evaluated in our Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL) accredited laboratory from 2002 to 2007, 144 patients had an EDV 100 to 124 cm/second. Of these, 47 patients underwent initial carotid intervention for concomitant symptoms (10), contralateral occlusion (3), or other imaging findings felt to warrant intervention. The remaining 97 asymptomatic patients were followed. One patient had both arteries fall within this EDV range. The mean follow-up for the 98 arteries was 29.1 months (range, 2-116 months).

RESULTS

Five patients (5.2%) developed ipsilateral symptoms consisting of one stroke and four transient ischemic attacks (TIAs), at a mean time of 35.3 months (range, 12-58 months). Twenty-six patients (26.8%), including 3 who also developed ipsilateral symptoms, progressed to having an EDV of ≥ 125 cm/second at a mean time of 24 months (range, 2-58). Two of these (2.1%) progressed directly to occlusion without symptoms and with no documented interim worsening of stenosis.

CONCLUSION

For asymptomatic individuals with an initial EDV of 100 to 124 cm/second, the risk of ipsilateral stroke is small and, therefore, medical management is appropriate in most cases. However, the risk of progression to a more severe degree of stenosis, often warranting carotid intervention, is clinically meaningful. Yearly duplex scan follow-up is necessary to assess disease progression in this patient cohort.

Are Hodgkin and non-Hodgkin patients at a greater risk of atherosclerosis? A follow-up of 3 years

Aims and background are to ascertain whether Hodgkin and non-Hodgkin patients are more affected by atherosclerotic process. We studied 96 patients during a period of 3 years (2003-2007). Patients were assessed in the first year soon after receiving radiotherapy and chemotherapy and then reassessed in the third year. All the cases underwent echo-colour Doppler of the carotid axis, and the intima-media thickness (IMT) was measured. When the two time points were compared, the IMT was greater in the arterial district examined at the first assessment; while at the second there was a reduction in the IMT, so patients seemed to improve with time. Flow-mediated dilatation did not improve. Hodgkin and non-Hodgkin patients experience an increase in IMT during treatment, but afterwards they return in their precedent condition. They seem to have a persistently reduced flow-mediated dilatation. Lymphoma therapy probably predisposes patients to early atherosclerosis, and it would be worth trying to reverse this tendency by administering antioxidant therapy.

Flow-Mediated Arterial Dilation in Primary Antiphospholipid Syndrome

Objective.

To investigate precocious alterations in the artery wall of patients with primary antiphospholipid syndrome (APS). Methods. We evaluated flow-mediated dilation (FMD) of the brachial artery and intima-media thickness (IMT) of carotid arteries in 16 patients and 16 healthy controls matched for age, gender, and other cardiovascular risk factors. Results. FMD of the brachial artery was significantly lower in patients than in controls (6.3 ± 5.2% vs 18.2 ± 2.7; P < .005). IMT was similar in the 2 groups. FMD was significantly reduced in patients with anticardiolipin antibodies IgM. Conclusions. APS correlates closely with precocious atherosclerosis, and the correlation with a type of anticardiolipin antibody may be predictive of more accelerated atherosclerosis.

Carotid and femoral atherosclerosis in chronic hepatitis C: a 5-year follow-up

The objective of this study was to assess the progression of atherosclerosis in carotid and femoral arteries after a 5-year period using ultrasound in subjects with chronic hepatitis C and in controls matched for classic atherosclerotic risk factors. A total of 40 patients and 40 controls were assessed by echocolor Doppler in 2001 and in 2006 to evaluate plaque and intima-media thickness. The patients showed no changes in plaque and intima-media thickness during the 5-year period in all districts examined, whereas a significant increase in intima-media thickness in the carotid sections was recorded in the controls. Chronic hepatitis C seems to cause delay in the atherosclerotic process.

Differences between middle cerebral artery blood velocity waveforms of young and postmenopausal women

OBJECTIVE

We characterized middle cerebral artery (MCA) blood flow velocity waveforms measured by transcranial Doppler ultrasonography in premenopausal (26.6 +/- 6.1 years, mean +/- SD) and postmenopausal (54.0 +/- 3.6 years) women, of whom six were receiving hormone therapy (PM-HT) and seven were not (PM-non-HT). We hypothesized that feature points on MCA waveforms are altered in postmenopausal women compared with those in young women.

DESIGN

A short protocol involved maintaining end-tidal PO2 at euoxia (88 mm Hg) and end-tidal PCO2 at 1.5 mm Hg above eucapnic values using a dynamic end-tidal forcing system. Doppler data for the velocity spectral outline (Vp) were collected every 10 ms, and velocity waveform analyses were done on a beat-by-beat basis. Waveform features were identified over each cardiac cycle, including the average Vp (VCYC), maximum acceleration (AMAX), and the ratio of the velocity at the reflected wave and the velocity at peak systole (VR:VMAX).

RESULTS

VCYC was unchanged between premenopausal and postmenopausal women (69.4 +/- 9.6 and 67.5 +/- 11.1 cm/s, respectively). AMAX was significantly higher (P = 0.007) in premenopausal women (987.9 +/- 280.7 cm/s) compared with postmenopausal women (743.1 +/- 100.3). Conversely, VR:VMAX was significantly smaller (P < 0.001) in premenopausal women (0.90 +/- 0.09) compared with postmenopausal women (1.11 +/- 0.05). In postmenopausal women, the reflected wave is higher than the maximum velocity at peak systole, suggesting the presence of a shoulder in the MCA waveform.

CONCLUSIONS

Further investigations are required to assess whether this waveform analysis can provide insight into pathophysiologic changes in cerebral hemodynamics with aging.

Comparison of carotid Doppler ultrasound and computerised tomographic angiography in the evaluation of carotid artery stenosis

PURPOSE

To compare results of carotid Doppler ultrasound (CDUS) and spiral computerised tomographic angiography (CTA) in patients with suspected carotid artery stenosis and to evaluate their combined effect on decision making for carotid endarterectomy (CEA).

METHODS

A total of 107 patients were studied. All of the patients had CDUS followed by CTA as a standard method of investigation. Data included the indications for investigation, stenosis degree measured in both modalities, in addition to difficulties and limitations faced while doing them.

RESULTS

Out of the 214 carotid scans performed, 187 scans were included in the comparison, while 27 scans were excluded due to inadequate data or imaging difficulties. The overall concordance between both CDUS and CTA was 79.1% (148/187) (95% CI 0.72-0.83). CDUS under-estimated and over-estimated the degree of stenosis in 26/187 (14%, 95% CI 0.09-0.19) and 13/187 (7%, 95% CI 0.04-0.12), respectively. When CTA was considered in conjunction with CDUS, the decision regarding operative treatment was changed in 29/187 cases (16%) (95% CI 0.11-0.21).

CONCLUSIONS

CDUS remains the first line non-invasive imaging for carotid artery stenosis. However, in cases where it is inconclusive, CTA is an excellent, reliable, minimally invasive, and outpatient alternative for patient selection for CEA.

Detection of Internal Carotid Artery Stenosis with Duplex Velocity Criteria Using Receiver Operating Characteristic Analysis

Introduction: Duplex ultrasonography is an excellent non-invasive screening tool for carotid artery stenosis. The aim of this study was to evaluate optimal ultrasonographic criteria for determination of internal carotid artery stenosis with reference to digital subtraction angiogra-phy. Materials and Methods: From January 1995 to December 2003, 114 symptomatic patients underwent both duplex ultrasonography and angiography. Seven velocity criteria were com-pared with angiographic stenosis and receiver operating characteristic curves were used to determine the best cutoff for each criteria. Results: Internal carotid artery/common carotid artery systolic velocity ratios (PSV ICA/PSV CCA) and systolic internal carotid artery/diastolic common carotid artery ratios (PSV ICA/EDV CCA) were superior to other criteria for diagnosing internal carotid artery stenosis. For 50% stenosis, the best criterion of PSV ICA/PSV CCA was 1.5 [sensitivity 100%, specificity 85%, area under the curve (AUC) 99%], and the best criterion of PSV ICA/EDV CCA was 3.5 (sensitivity 100%, specificity 58%, AUC 99%). For 60% stenosis, the best criterion of PSV ICA/PSV CCA was 2.6 (sensitivity 100%, specificity 94%, AUC 99%), and the best criterion of PSV ICA/EDV CCA was 10.3 (sensitivity 100%, specificity 96%, AUC 99%). For 70% stenosis, the best criterion of PSV ICA/PSV CCA was 3.1 (sensitivity 100%, specificity 91%, AUC 99%), and the best criterion of PSV ICA/EDV CCA was 10.3 (sensitivity 100%, specificity 91%, AUC 99%). Conclusion: Our study showed that velocity ratios are superior to other criteria for detecting carotid stenosis. Each laboratory needs to validate its own results. Key words: Angiography, Duplex, Extracranial, Internal carotid artery

Carotid Ultrasound Criteria for Detecting Intracranial Carotid Stenosis

BACKGROUND/AIMS

This study attempted to establish carotid ultrasound criteria for identifying stenosis of the intracranial internal carotid artery (ICA) and middle cerebral artery (MCA).

METHODS

Two hundred and fifty-five patients were enrolled. Ultrasound measurements for common carotid artery (CCA) and ICA were as follows: flow volume (FV), peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistance index (RI). The sensitivity and specificity of the ultrasound criteria for determining intracranial ICA or MCA>or=50% stenosis were calculated.

RESULTS

The criteria identified for detecting intracranial ICA>or=50% stenosis were ICA FV<159 ml/min, ICA PSV<33 cm/s and CCA PSV<42 cm/s. When ICA PSV<33 cm/s was combined with CCA PSV<42 cm/s, sensitivity increased to 82%, with 91% specificity. The criteria identified for detecting MCA>or=50% stenosis were CCA FV<285 ml/min, ICA FV<179 ml/min, ICA PSV<33 cm/s, >35% reduction in FV in the CCA, >40% reduction in FV in ICA, and >35% reduction in PSV in ICA. When these criteria were combined, sensitivity increased to 69%, with 85% specificity.

CONCLUSION

This study demonstrated that ultrasound criteria are sensitive and specific for detecting intracranial ICA and MCA significant obstruction.

Carotid sonography and transesophageal echocardiography in patients with ischemic stroke or transient ischemic attack in the territory of the carotid artery

PURPOSE

To assess the benefit of combining carotid sonography and transesophageal echocardiography (TEE) for the evaluation of patients with stroke or transient ischemic attack (TIA) in the territory of the carotid artery.

METHODS

During a 2-year period in Turku University Hospital, consecutive in patients with stroke or TIA who were candidates for carotid endarterectomy and for oral anticoagulation were evaluated with carotid sonography for symptomatic moderate (50-69%) or severe (>or=70%) internal carotid artery (ICA) stenosis, and with TEE for potential cardiac sources of embolism.

RESULTS

In 20% (40/197) of patients, a severe symptomatic ICA stenosis and/or a major risk factor for a cardiac source of embolism were found. In 56% (110/197) of patients, a moderate or severe symptomatic ICA stenosis and/or a potential cardiac source of embolism were found, whereas 11% (21/197) of patients had both a moderate or severe symptomatic ICA stenosis and a potential cardiac source of embolism.

CONCLUSIONS

This study suggests that the presence of a moderate or severe symptomatic ICA stenosis does not exclude the presence of a potential cardiac source of embolism and vice versa. Carotid sonography and TEE complement each other and are valuable diagnostic tools that should be recommended in patients with ischemic stroke or TIA in the territory of the carotid artery when they are candidates for carotid endarterectomy and for oral anticoagulation.

Does hemophilia protect against atherosclerosis? A case-control study

Whether carriers of hemophilia are protected against the development of atherosclerosis is controversial. In a case-control study, the presence of atherosclerosis was assessed and quantified with echo-color Doppler of all explorable arterial districts in 50 carriers of hemophilia and in 50 age-matched control individuals. All participants submitted to echo-color Doppler of carotid and femoral axis, of brachial arteries, and of the abdominal aorta. The presence and grade of atherosclerotic plaques were assessed, as well as the intima-media thickness (IMT). At least one atherosclerotic plaque was found in six cases (12.0%) versus 15 controls (30.0%); referring to the total number of plaques, 30% of them were evaluated in patients affected by decreased coagulation while 70% in subjects with normal levels of FVIII. In all the examined districts, the mean IMT was significantly lower in patients with hemophilia than in controls. Hemophilia protects against asymptomatic atherosclerosis.

Duplex Ultrasound Verified by Angiography in Patients with Severe Primary and Restenosis of Internal Carotid Artery

There are very limited data in the literature about the reliability of duplex ultrasound (DU) verified by angiography in patients with restenosis of the internal carotid artery (ICA) after carotid surgery compared with primary carotid artery stenosis patients. Our objective was to compare the reliability of DU verified by conventional angiography in the diagnosis of severe primary stenosis versus restenosis of ICA. One hundred thirty-four patients (238 arteries) were examined by both DU and angiography. Severe stenosis (>70%) was found in 47 primary stenotic arteries and in 70 restenotic arteries. Accuracy, specificity, sensitivity, positive predictive value (PPV), and negative predictive value were obtained for basic DU criteria after verification of ultrasound data by angiography. The best accuracy for detection of >70% stenosis by end diastolic velocity was found for the velocity of 70 cm/sec or more in both groups, but accuracy for the restenosis group was significantly higher (96.9% vs. 89.8%, p = 0.025). Additionally, specificity (p = 0.01) and PPV (p = 0.01) were significantly higher in the restenosis group. The best accuracy for detection of >70% stenosis by peak systolic velocity was found for the velocity of 220 cm/sec or more for restenoses and 200 cm/sec or more for primary stenoses. The accuracy of the ultrasound was significantly higher in the restenosis group (94.6% vs. 87%, p = 0.04), as were specificity (p = 0.01) and PPV (p = 0.02). The diagnosis of severe restenosis by DU is reliable and can be used for decision making regarding surgery or stenting without angiography. In patients with Doppler parameters pointing to borderline moderate/severe primary carotid stenosis and technically complicated cases, angiography in addition to sonography before surgery is recommended.

The reliability of ultrasound measurements of carotid stenosis compared to MRA and DSA

OBJECTIVE

Carotid ultrasound (US) is a screening test for patients with transient ischemic attacks (TIAs) or stroke who then undergo Digital Subtraction Angiogram (DSA) or Magnetic Resonance Angiography (MRA). Gold standard DSA is invasive with inherent risks and costs. MRA is an evolving technology. This study compares reliability of MRA and US modes with DSA in determining degree of internal carotid artery stenosis.

METHODS

A five year retrospective analysis of 140 carotid arteries from patients who had carotid US and DSA, and possibly Magnetic Resonance Angiography was undertaken. Recorded US parameters were peak systolic velocity (PSV), end diastolic velocity (EDV), and ICA/CCA peak systolic velocity ratio. The MRA and DSA parameters used NASCET technique for measuring stenosis. Statistical analysis included ROC curves and Kappa computation.

RESULTS

US grading of carotid stenosis can be made more reliable by choosing appropriate parameters. The best combination of sensitivity and specificity for stenosis > 70% in our hospital was seen at PSV > 173 cm/s (sensitivity 0.87, specificity 0.8, Positive Predictive Value (PPV) 0.70, Negative Predictive Value (NPV) 0.93, kappa 0.64 and weighted kappa 0.71). MRA kappa was 0.78, (sensitivity 0.75, specificity 1.0, PPV 1.0, NPV 0.85).

CONCLUSIONS

US parameters should be validated in each centre. At best, US can only approximate the accuracy of DSA, probably due to inherent limitations of this modality. Magnetic Resonance Angiography has a perfect specificity and PPV but this technique needs to be standardized. Simultaneous use of MRA and US for screening increases sensitivity to over 0.9 without compromising specificity in > 70% stenosis.

Risk factors for periprocedural complications in carotid artery stenting without filter protection

INTRODUCTION

In high-grade stenosis, carotid artery stenting (CAS) may be chosen as an alternative to carotid surgery. Ischemic periprocedural complications may be documented best with diffusion-weighted MRI (DWMRI). In this prospective study serial DW-MRI and color-coded duplex sonography (CCDS) were used to identify carotid stenosis, which is associated with an increased risk of ischemic events due to CAS.

METHODS

High resolution DW-MRI were performed in 74 out of 77 patients before and after CAS. All MRI scans were analyzed in a blinded manner. With CCDS each carotid stenosis was evaluated according to the grade, length, echo properties and plaque surface.

RESULTS

In 42 out of 74 patients (56.8 %) a total of 188 new procedure- related DWI-lesions could be detected, while in 32 patients MRI-controls remained normal. Of the lesions 79.25 % had a size < 1 cm. In one major and two minor strokes due to CAS (total complication rate 3.9 %) corresponding territorial infarcts could be demonstrated. A highly significant correlation was found between the length of the stenosis and the incidence of new DWI-lesions (p = 0.0141). In contrast, neither the grade of ICA stenosis nor the sonographic plaque morphology or plaque surface correlated with the number of DWI-lesion in postinterventional scans.

CONCLUSIONS

The length-and not the degree-of an ICA stenosis seems to be the most decisive sonographic factor for estimating the periprocedural risk of embolism. DWI-lesions are much more frequent than clinical complications and may represent an important surrogate marker for improving the techniques of carotid artery stenting, especially comparing the benefit of different mechanical protection devices.

Place de l’écho-Doppler cervico-encéphalique dans l’ischémie cérébrale

Carotid stenosis is a common cause of ischemic stroke. The management of patients with a carotid lesion is mainly based on the degree of stenosis. Ultrasonography is a reliable and accurate method of quantification of the stenosis. The sonographic quantification is based on both velocity and morphological criteria. B mode, color or power Doppler as well as spectral Doppler are used for this purpose. The actual velocity criteria for a 70% stenosis (NASCET definition) are as follows: maximal systolic velocity above 230 cm.s-1, telediastolic velocity above 100 cm.s-1, carotid ratio above 4. The morphological quantification of the stenosis relies on Doppler imaging and B-mode coupling. With ultrasound, the residual area can be measured using a short axis plane, and the diameter reduction using a longitudinal plane. The different parameters provide complementary information that must be in agreement with one another. There is a growing interest in plaque characterization. Undoubtedly plaque structure and surface appearance also play a role in the individual risk of stroke. Thus, B-mode plaque analysis must be an integral part of the ultrasonographic examination. Transcranial Doppler is a complementary investigation that can be used to evaluate the hemodynamic consequences of the stenosis and to look for intracranial lesions. Optimal sonographic examination currently allows comprehensive evaluation of a carotid lesion.