Contrast enhanced ultrasound of carotid plaque in acute ischemic stroke (CUSCAS study).

INTRODUCTION: Carotid atherosclerosis represents 8 to 15% of ischemic strokes in relation to the concept of "vulnerable" plaque. Contrast enhanced ultrasound (CEUS) can detect moving microbubbles within the plaque corresponding to neovessels that constitute "precursors" of vulnerable plaque and intraplaque hemorrhage. CEUS was not studied specifically in acute ischemic strokes. The aim of this study is to analyse the prevalence of CEUS carotid plaque ipsilateral at the ischemic stroke as well as the main characteristics of contrast-plaques. METHOD: A single-centre prospective pilot study involving 33 consecutive patients with a stroke ≤10 days, diagnosed by an MRI with positive diffusion sequence and having a carotid plaque thickness ≥2.5mm with low or heterogeneous echogenicity, located in the ipsilateral carotid territory at the stroke. Plaque echogenicity was done by visual analysis and by measurement of the gray scale median (GSM). A transcranial Doppler monitoring was carried out in search of HITS. The contrast ultrasound was performed after 2.5 cc IV injection of SonoVue®. A video clip was recorded after injection which was used for interpretation by visual analysis in 3 grades, provided by two independent expert readers. RESULTS: The population consisted of 10 women and 23 men aged 73 on average. The topography of strokes in the carotid territory was located on the right in 11 (33%) cases and on the left in 22 (67%) cases. Seventeen patients had carotid stenosis between 0 and 49% according to the Nascet method and 16 patients had stenosis of 50 to 99%. The visual characterisation of the plaques had echolucent dominance (Type 1-2) in 18 cases and echogenic dominance (Type 3-4a) in 15 cases. Cardiovascular risk factors were common with no difference by sex. The inter-observer agreement of plaque enhancement was moderate in first reading (k=0.48) and excellent at consensus (k=0.91). Only one disagreement was found. Contrast agent enhancement of carotid plaque was observed in 11/32 patients, representing a prevalence of 34.4% - CI95% [17.9-50.9]. Variables associated with contrast plaque included the absence of antiplatelet drug (63.6% vs. 23.8%, P=0.05) and the presence of a regular edge on the plaque (91% vs. 48%, P=0.04). There was no difference in contrast enhancement for stenosis>or<50% in diameter and neither for the type of plaque. CONCLUSION: In a consecutive cohort of 33 patients, the prevalence of CEUS from an ipsilateral carotid plaque to a recent acute ischemic stroke was 34.4%. There was a statistically significant association between the contrast enhancement of the plaque and the absence of antiplatelet drug (P=0.05) and also the presence of a regular edge on the plaque (P=0.04). There was no correlation between plaque contrast and clinical and biological characteristics of patients or the presence of HITS.

[Contribution of contrast enhanced ultrasonography in the characterization of carotid lesions]. / Apport de l'échographie de contraste dans la caractérisation des lésions carotidiennes.

Harmonic mode ultrasound with injection of a contrast enhancement agent allows visualization of mobile microbubbles in the carotid plaque corresponding to neovessels secondary to an inflammation or hypoxia. These neovessels could be considered "precursor" markers of the vulnerable plaque. The aim of this work was to give an update on ultrasound contrast imaging acquisition in the exploration of carotid artery both for atheromatous lesions and for large vessel vasculitis. A precise description of the material to be used, the image acquisition methodology and the environmental conditions is discussed, emphasizing the pitfalls to be avoided as well as proper image interpretation. Microbubbles in a plaque are significantly associated with an increase in cardiovascular events (infarction and acute coronary syndrome) and ipsilateral cerebral ischemic events. Wall irregularities, microfissures and ulcer plaque detection are facilitated by the use of contrast compared to the CT scan. No studies have yet validated contrast enhanced ultrasound in the exploration of asymptomatic carotid stenosis. Contrast enhanced ultrasound also allows to detect vasculitis of the large vessels active phases by the presence of microbubbles in the carotid wall thickening and to monitor the regression under appropriate medical treatment. Future validation studies or even registries are needed to allow better use of this tool in everyday clinical practice.

[Venous thromboembolic disease: Comparison of management practices in France, Italy and Spain]. / Comparaison en France, en Italie et en Espagne des modalités de prise en charge de la maladie thromboembolique veineuse.

BACKGROUND: Many national and international guidelines have been established for venous thromboembolic disease (VTE). Homogeneous management practices could be expected in the different European countries. To verify this hypothesis, we compared practices in France, Italy and Spain. METHOD: We used data from the international RIETE registry to compare VTE management between France, Italy and Spain. RESULTS: From 2001 January to 2011 January, patients were consecutively included in France (n=1548), Italy (n=2083) and Spain (29,824). All patients received anticoagulant treatment. Low molecular-weight heparin (LMWH) was the most frequently used drug as initial therapy in all three countries, but unfractionated heparin (UFH) was more frequently used in France and Italy than in Spain. In France, the proportion of patients receiving LMWH was lower than the proportion of patients with active cancer (cancer 22.5 %, long-term treatment with LMWH 17.4 %). A vena cava filter was significantly more frequently used in France (5.5 % in France, 3.2 % in Italy and 2 % in Spain, P<0.0001). High bleeding risk because of surgery with recent thromboembolic disease was the most frequent indication in France and Italy for vena cava filter placement (36.4 %, and 31.3 %, respectively). CONCLUSION: Despite the publication of national and international guidelines, VTE management differs among the three major European countries included in the RIETE registry, France, Italy and Spain.

Carotid diaphragm: Atypical fibromuscular dysplasia or atheromatous lesions?

Atypical fibromuscular dysplasia (FMD) is an underdiagnosed cause of ischemic stroke. The typical angiographic pattern of a septum on the posterolateral side of a carotid megabulb is highly suggestive of atypical FMD. We report here on two patients with this highly suggestive pattern of carotid atypical FMD, but which histological examination revealed to be atheromatous lesions. Interestingly, contrast-enhanced ultrasound of the carotid artery showed enhancement of the spur, which should never be the case with an FMD lesion, which has no vasa vasorum. Our findings suggest that the results of studies reporting stenting of atypical FMD in cervical arteries should be interpreted with caution.

[Contrast enhanced ultrasound can show symptomatic carotid lesions not visualized with magnetic resonance angiography]. / L'échographie avec contraste peut montrer des lésions carotidiennes symptomatiques non visualisées en angio-RM.

We report the cases of two patients who presented symptoms focused on a wall of the common carotid: carotidodynia in one patient and a transient ischemic attack in the other. The B-mode ultrasound showed an enlarged thickened medio-adventitial echostructure with a slightly heterogeneous and iso or hypoechoic appearance. There was no narrowing. Injection of ultrasound contrast led to significant enhancement in the wall reflecting neovascularization secondary to inflammation. Other imaging methods (MR and CT angiography) found no abnormality. At the 3-month follow-up visit, the surface area of the lesions was greatly decreased and the ultrasound contrast enhancement had disappeared. These two cases illustrate how focal lesions of the carotid wall missed on MR and CT angiography can be detected and visualized with B-mode ultrasound contrast enhancement. Contrast enhanced ultrasound leads to the concept of "active lesions" resulting from inflammatory processes that can be readily monitored without radiation.