Carotid Thromboendarterectomy Research Articles

The Pre- and Postoperative Prevalence and Risk Factors of ASA Nonresponse in Vascular Surgery

BackgroundAn antiplatelet therapy with acetylsalicylic acid (ASA) is prescribed in the prevention of cardiovascular events, but around 24% of ASA takers are resistant to the treatment.AimIn this prospective, observational cohort study, we aimed to identify the prevalence and risk factors of ASA nonresponse in patients who underwent vascular surgery.MethodsThe study was conducted in the University hospital in Frankfurt am Main. In total, 70 patients were pre-treated with 100 mg of ASA per day and underwent either elective carotid thromboendarterectomy, femoral thromboendarterectomy or endovascular aneurysm repair of the abdominal aorta. The platelet function was measured on the first preoperative and the second or fourth postoperative day with the multiple electrode aggregometry by in-vitro stimulation with arachidonic acid (ASPItest) and thrombin receptor activating peptide 6 (TRAPtest). The primary end point was the in-vitro induced platelet aggregation in the ASPItest. If the ASPItest amounted ≥400 AU × min, the patients were categorized as ASA nonresponders.ResultsThe total prevalence of ASA nonresponse in our study was 20% preoperatively and 35.7% postoperatively (p = 0.005). As significant predictors for ASA nonresponse, we demonstrated the area under the aggregation curve in the TRAPtest preoperatively (p = 0.04) and postoperatively (p = 0.02), and the two comorbidities arterial hypertension (P < .001; rho 0.44) and diabetes mellitus (p = 0.04; rho 0.39), which are already well known to be associated with ASA nonresponse.ConclusionIn conclusion, data of the study indicate a high incidence of perioperative, laboratory ASA nonresponse in patients undergoing vascular surgery.

Short- and Long-Term Outcomes Following Biological Pericardium Patches Versus Prosthetic Patches for Carotid Endarterectomy: A Retrospective Bicentric Study

Currently, there are various types of patches available on the market for carotid endarterectomy (CEA) with enlargement angioplasty, prosthetic, and biological patches including bovine pericardial patches. Despite the increasing use of these biological patches, there are little data in the literature comparing the results of these 2 types of patch. The purpose of this study is to compare the short- and long-term results of bovine pericardium patches (BPPs) with prosthetic patches (PPs) in carotid thromboendarterectomy. This study presents a retrospective analysis of all CEAs performed at Montpellier and Nîmes University Hospitals (France) in 2014 and 2015. Patients who underwent eversion were excluded. Preoperative, peroperative, and postoperative clinical and Doppler ultrasound results were collected and analyzed. The primary end point was the comparison of the restenosis rate between the BPP and the PP group. Secondary end points were the analysis of restenosis risk factors (type of patch, gender, renal failure, smoking, diabetes, arterial hypertension, dyslipidemia, and redo surgery were analyzed); the comparison of morbidity-mortality and infection between the BPP and the PP group and the comparison of morbidity-mortality between symptomatic and asymptomatic stenosis. In total, 342 CEAs were performed: 168 (49%) with BPP and 174 (51%) with PP. Median follow-up was 30months (interquartile range=24). The stroke rate at day 30 was 3.22% and mortality at day 30 was 1.86%. There was no significant difference between groups concerning anyone of the variables of interest. At the end of follow-up, the restenosis rate >50% was 7.31% (6.45% for the BPP group vs. 8.22% for the PP group, P=0.55). The severe restenosis rate (>70%) was 4.65% (5.16% for the BPP group vs. 4.11% for the PP group, P=0.79). The univariate analysis identified renal failure (odds ratio=2.69) as the main risk factor. The postoperative infection rate was 1.17% (0.59% for the BPP group vs. 1.75% for the PP group, P=0.62). The rates of stroke and postoperative death, bleeding, infection, and restenosis are comparable between BPPs and PPs in our study. The use of prosthetic or biological patches seems to deliver comparable outcomes. Further studies on larger samples are required.

CAR 10. Endarterectomy for Acute Symptomatic Thrombotic Occlusion of the Entire Extracranial Internal Carotid Artery: A Case Report

We report the case of a 60-year-old woman who was admitted with a sudden onset of numbness of the left upper extremity. Two weeks before admission, the patient presented with a right hemispheric transient ischemic attack and temporary right facial paresis. Duplex ultrasound and magnetic resonance (MR) angiography revealed an occlusion of the right internal carotid artery (ICA) as well as a high-grade stenosis of the left ICA with patency of the cerebral arteries (middle cerebral artery [MCA]). A cranial computed tomography scan showed a small hypodense lesion of the right hemisphere and several lacunar infarctions without signs of intracranial bleeding. An exploration of the right carotid bifurcation was performed, and an atherosclerotic plaque at the carotid bifurcation with a fresh clot downstream was found. Thrombectomy was performed using a 2F balloon catheter, resulting in a sufficient backflow from the ICA. In addition, thromboendarterectomy with patch plasty was performed. On the final intraoperative angiogram, the entire right ICA and the downstream intracranial vessels were patent. Intraoperative duplex ultrasound confirmed a sufficient hemodynamic profile without major turbulences. The postoperative MR angiogram confirmed patency of the ICA with an undisturbed perfusion of the right hemisphere. The postoperative course was uneventful; no neurologic symptoms occurred, and she was discharged on postoperative day 8. Six weeks later, the left ICA stenosis (North American Symptomatic Carotid Endarterectomy Trial [NASCET] 90%) was treated successfully by conventional thromboendarterectomy. During follow-up of 61 months, no neurologic or cardiac events occurred. A recurrent ICA stenosis was not detected. Comparing the perfusion of the right MCA with the preoperative MR angiogram, we conclude that a sufficient blood supply to the right MCA could probably not have been achieved by a simple left-sided carotid thromboendarterectomy. Whereas chronic ICA occlusion is generally accepted as a condition not suitable for extracranial reconstruction, our patient profited from revascularization as she suffered from an acute occlusion on top of a chronic stenosis. It remains uncertain which occluded artery should be explored and, specifically, at what time. In symptomatic patients, exploration of the ICA and carotid bifurcation might be justified to restore blood flow and to prevent a severe stroke event.

Place of carotid surgery in the management of CVAs

The purpose of the creation of neuro-vascular units (NVU) is an optimal early management of the patients presenting a cerebral vascular accident (CVA). In parallel, it is recommended to perform carotid thrombo-endarterectomy (TE) in the 15 days following transient or permanent CVA in presence of a symptomatic stenosis >50%. The aim of our study was to evaluate the place of early carotid surgery among the patients treated for CVA in a center having a NVU.

Emergent Carotid Thromboendarterectomy for Acute Symptomatic Occlusion of the Extracranial Internal Carotid Artery.

Strokes secondary to acute internal carotid artery (ICA) occlusion are associated with an extremely poor prognosis. The best treatment approach in this setting is still unknown. The aim of our study was to evaluate the efficacy, safety, and outcomes of emergent surgical revascularization of acute extracranial ICA occlusion in patients with minor to severe ischemic stroke. A retrospective analysis was performed using prospectively collected data of consecutive patients who underwent carotid thromboendarterectomy for symptomatic acute ICA occlusion during the period from January 2013 to December 2015. Primary outcomes were disability at 90 days assessed by the modified Rankin Scale (mRS) and neurological deficit at discharge assessed using the National Institute of Health Stroke Scale (NIHSS). Secondary outcomes were the recanalization rate, 30-day overall mortality, and any intracerebral bleeding. During the study period, a total of 6 patients (5 men and 1 woman) with a median age of 64 years (range: 58-84 years) underwent emergent reconstruction for acute symptomatic ICA occlusion within a median of 5.4 hours (range: 2.9-12.0 hours) after symptoms onset. The median presenting NIHSS score was 10.5 points (range: 4-21). Before surgery, 4 patients (66.7%) had been treated by systemic recombinant tissue plasminogen activator lysis. The median time interval between initiation of intravenous thrombolysis and carotid thromboendarterectomy was 117.5 minutes (range: 65-140 minutes). Patency of the ICA was achieved in all patients. On discharge, the median NIHSS score was 2 points (range: 0-11 points). There was no postoperative intracerebral hemorrhage and zero 30-day mortality rate. At 3 months, 5 patients (83.3%) had a good clinical outcome (mRS ≤ 2). Patients presenting with minor to severe ischemic stroke syndromes due to isolated extracranial ICA occlusion may benefit from emergent carotid revascularization. Thorough preoperative neuroimaging is essential to aid in selecting eligible candidates for acute surgical intervention.

Surgical management of free-fl oating thrombus within the common carotid artery

Free-floating thrombus (FFT) of the carotid artery is an exceptional medical condition with a currently unclarified pathophysiology. Approximately 150 cases have been described and published in the literature throughout the world so far. Thus, no definite management strategies have been established yet. In this paper, a symptomatic case of an FFT inside the common carotid artery (CCA) presented with a history of slurred speech, and right sided hemiplegia was reported. After the diagnosis of a mobile thrombus within the origin of the left CCA, the patient was placed on anticoagulation. As the medical therapy failed, carotid thromboendarterectomy was performed.

Surgical Management of Free-floating Thrombus within the Common Carotid Artery

Free-floating thrombus (FFT) of the carotid artery is an exceptional medical condition with a currently unclarified pathophysiology. Approximately 150 cases have been described and published in the literature throughout the world so far. Thus, no definite management strategies have been established yet. In this paper, a symptomatic case of an FFT inside the common carotid artery presented with a history of slurred speech, and right sided hemiplegia was reported. After the diagnosis of a mobile thrombus within the origin of the left common carotid artery, the patient was placed on anticoagulation. As the medical therapy failed, carotid thromboendarterectomy was performed.

Symptomatic free-floating carotid thrombus extending to the skull base

A 58-year-old woman presented to the emergency department with progressive amaurosis fugax with a background of hypertension, hypercholesterolemia, and current smoking. Carotid duplex ultrasound demonstrated an 80%–99% stenosis at the origin of the right internal carotid artery (ICA). CT angiogram revealed a high-grade focal stenosis of the origin of the right ICA with a 7-cm free-floating thrombus (FFT) extending to the skull base (figure 1, video 1 at [Neurology.org/cp][1]). The incidence of FFT in patients undergoing carotid imaging has been reported as 0.05%–0.7%.1 It is more frequently reported in men than women, with a ratio of nearly 2:1. The ICA is the most commonly affected (75%), with atherosclerosis being the most common associated pathology. It is a highly unstable condition with acute neurologic symptoms present in greater than 90% of cases. Urgent management with anticoagulation alone, anticoagulation followed by delayed carotid surgery, or immediate carotid surgery (open and endovascular) is described, but there is no evidence of superiority of any of these strategies (level of evidence Class IV).1,2 Our patient underwent immediate right carotid thromboendarterectomy with retrieval of complete thrombus (figure 2, video 2 at [Neurology.org/cp][1]). The postoperative course was uncomplicated and she was discharged 3 days later with no further episodes of amaurosis fugax and normal vision. [1]: http://Neurology.org/cp

Computed Tomography Perfusion Imaging in the Selection of Acute Stroke Patients to Undergo Emergent Carotid Endarterectomy

Severe acute stroke patients with critical carotid stenosis or occlusion without intracranial thrombus typically do not undergo emergent carotid thromboendarterectomy (CEA) because of the risk of reperfusion-related intracranial hemorrhage. Past studies have not consistently demonstrated benefit of early operative intervention. Cerebral computed tomography (CT), cervical and cerebral CT angiography (CTA), and cerebral CT perfusion (CTP) imaging may identify a subset of acute stroke patients without intracranial thrombus who may benefit from emergent CEA. Acute stroke patients underwent unenhanced brain CT imaging to exclude pathology that would contraindicate emergent therapy. Emergent CTAs of the intracranial and extracranial vessels were utilized to identify patients who presented with stroke symptoms based on the presence of isolated extracranial carotid disease in the absence of intracranial thromboembolism. CTP was then used to assess the extent of potentially reversible cerebral ischemia (penumbral tissue). Patients with isolated extracranial carotid lesions with significant reversible ischemia in the absence of large areas of irreversible cerebral damage underwent emergent CEA to salvage ischemic penumbra. In 1 year, 3 patients presented with large acute strokes in which CTA disclosed symptomatic extracranial internal carotid artery preocclusive or occlusive lesions without intracranial thromboembolic occlusions. CTP indicated a large area of ischemic penumbra with limited permanent injury. Mean age, time to presentation, and National Institutes of Health stroke score (NIHSS) were 66 years, 4.2 hr, and 19.3. All patients underwent emergent CEA with cervical carotid thrombectomy. Average time from stroke symptom onset to revascularization was 12.5 (range 5.9-19.0) hr. There were no perioperative deaths. At day 5, the mean NIHSS decreased to 7.6 and at day 30 was 4.7. The modified Rankin scale score dropped from a poststroke, preoperative level of 5 to 2.3 by day 30. Emergent CEA should be considered in patients presenting with large acute strokes based on favorable CT, CTA, and CTP findings. Emergent clot localization and physiological assessment of brain "tissue at risk" relative to irreversible cerebral infarction using CT, CTA, and CTP is now available. Utilization of this information by an experienced stroke team of neurologists, radiologists, and surgeons may aid in the recognition of a select group of patients in which emergent CEA may drive to improved outcomes.

Teaching Neuro Images : Combined retinal and cerebral hyperperfusion syndrome after carotid thromboendarterectomy

A 62-year-old man presented with mild left hemiparesis, headache, and blurred vision of his right eye. Ten days before, he had undergone thromboendarterectomy because of subtotal stenosis of his right internal carotid artery. MRI revealed confluent white matter edema together with focal hemorrhage consistent with cerebral hyperperfusion syndrome (CHS; figure 1). Likewise, funduscopy showed small retinal hemorrhages confined to the right eye (figure 2). Under careful blood pressure control, symptoms and brain edema fully resolved within weeks. CHS occurs in around 3% of patients undergoing carotid thromboendarterectomy and can induce severe neurologic deficits.1 Rarely, hyperperfusion also involves the ipsilateral eye.2

Composition and Genesis of Calcium Deposits in Atheroma Plaques

The composition of atheromatous plaque determines its progression toward rupture or thrombosis. Although its histopathological structure has been widely studied, little attention has been paid to its structural and chemical composition and even less to its mineral component. Thirty-three atheromatous plaques were obtained by carotid thromboendarterectomy. Three types of materials were observed under polarized light microscopy: apatite crystals in the form of glomeruli (dark with plane polarized illumination and greensh with cross-polarized illumination); fibrous-like cholesterol (uncolored or grayish with plane-polarized illumination); and amorphous organic material as brownish deposits. SEM-EDX analysis showed an abundance of phosphorus and calcium in sufficient quantities to form calcium phosphates, and appreciably reduced levels of sodium. X-ray diffraction results differentiated samples into three groups: group I with predominance of hydroxyapatite-type crystals, group II with crystalline material containing an amorphous component, and group III with wholly amorphous material. The most abundant mineral in atheromatous plaque is hydroxyapatite, on which crystals of cholesterol and lipid nuclei are deposited, stratifying the plaque into layers that reflect the different stages of its formation. The difference in calcium and sodium concentrations between arteries with and without atheromata may indicate an important relationship in the pathophysiological development of calcium deposits.

Operative Therapie der hochgradigen, asymptomatischen Karotisstenose

Surgery of carotid artery stenosis is an evidence-based procedure. In Germany approximately 25 percent of the strokes are caused by arteriosclerotic processes in the extracranial internal carotid artery and are consequently potentially avoidable by an appropriate treatment. The symptoms, the stenosis degree as well as the perioperative risk represent the basis for the indication. The perioperative complication rate should be under 3 percent for those cases with asymptomatic stenoses and under 6 percent for those with symptomatic stenoses. The most frequently applied operation procedures comprise carotid thrombo-endarterectomy (TEA) including patch graft and the eversion endarterectomy. In the following video we present both methods in a 76-year-old female patient with an asymptomatic 95 percent stenosis as well as in an 84-year-old female patient with an asymptomatic 85 percent stenosis operated under regional anaesthesia. Regional anaesthesia is performed through installation of a high cervical block under reclination of the head to the contralateral side. Then incision of the skin and the platysma along the front of the sternocleidomastoid muscle. Preparation of the carotid bifurcation with minimal manipulation as well as protection of the surrounding neural structures. Afterwards clamping of the vessels under permanent neurological monitoring and controlled hypertonia. Open thrombo-endarterectomy after longitudinal arterial incision with plaque removal en bloc and closure by using a bovine patch graft in four-point seam technique. This method should be preferred in cases with long-segment stenosis as well as in cases with a small lumen internal carotid artery. In the framework of eversion endarterectomy, we perform a tangential resection of the ACI on the bifurcation. The plaque cylinder is mobilised afterwards and is removed through eversion of the whole vessel. Then the reinsertion of the ACI in the bifurcation can be performed with an additional shortening of the artery in cases of kinking. In this way short- segment stenosis lend themselves to fast and safe treatment. In all cases digital subtraction angiography is recommended by the authors for intraoperative quality monitoring. In the hands of experienced vascular surgeons, the open carotid TEA including patch graft and the eversion endarterectomy under regional anaesthesia represent highly effective procedures for symptomatic/asymptomatic carotid stenosis. The S3-guidelines for the therapy of carotid artery stenosis will be published this year and should be consulted for the interdisciplinary therapy decision.

Etiology of late cerebrovascular events after carotid endarterectomy

Progressive carotid artery disease has been shown to cause cerebrovascular events years after a patient's carotid thromboendarterectomy (CEA). Yet, some late cerebrovascular events in CEA patients are attributable to other etiologies. We sought to determine frequency and characteristics of late cerebrovascular events in post-CEA patients attributable to etiologies other than progressive carotid disease. In a post hoc analysis of data from a CEA-registry with long-term follow-up, all patients with transient ischaemic attack (TIA) or stroke occurring >1 month post-CEA were identified. The etiologies of these events were dichotomized into the groups large-artery atherosclerosis (LAA) and that non-large-artery atherosclerosis (non-LAA), i.e. all other etiologies (Trial of Org 10172 in Acute Stroke Trial-criteria). Frequency and characteristics of both groups were compared. Sixty of 361 post-CEA patients (16.6%; 95%CI 12.9-20.9%) had late cerebrovascular events after 7 years (median). Thirty patients had ischaemic strokes and 30 had TIAs. These events were attributable to LAA in 48% (29/60) and to non-LAA in 52% (31/60). In the LAA group, contralateral carotid stenosis (62%; 18/29) was more frequent than recurrent ipsilateral stenosis (38%; 11/29). Amongst non-LAA patients, cardioembolism (29%; 9/31) and small-artery-occlusion (23%; 7/31) were the most frequent causes. LAA and non-LAA patients did not differ in age, time since CEA, risk factor profile, type of event, and baseline medication. In post-CEA-patients, half of the late cerebrovascular events were attributable to etiologies other than LAA. Clinical features did not distinguish LAA-events from non-LAA events. Thus, stroke prevention in post-CEA patients should not be confined to screening for progressive carotid disease but includes efforts to optimize the management of risk factor and cardiac diseases.

Lessons from two decades of surgical audit

PurposeThe purpose of this paper is to report on the use of a computer database used by medical secretaries to routinely and continuously store information on the work of a hospital consultant in order to monitor clinical activity and patient outcomes.Design/methodology/approachThe methodology uses database software developed to deal with discharge summaries, outpatient attendances, operation notes and in‐hospital ward referrals.FindingsFrom October 1984 to June 2006 there were 18,743 discharge summaries and from 1991 15,827 outpatient and 6,199 operation notes. The paper demonstrates changing clinical practice over more than 20 years and reduction in the number of postoperative complications and patients having second operations during the same admission. There is also evidence of conformity to expected outcomes for patients having carotid thromboendarterectomy and grafting of aortic aneurysm.Originality/valueThe paper shows that computer software of this type can operate seamlessly to document clinical activity and should be in use by all consultants working in the National Health Service.

Metalloproteinase Expression in Carotid Plaque and Its Correlation With Plasma Levels Before and After Carotid Endarterectomy

To assess baseline and follow-up plasma concentrations of metalloproteinase-9 (MMP-9), MMP-2, and tissue inhibitor of metalloproteinase-2 (TIMP-2) in patients undergoing carotid thromboendarterectomy (TEA) in relation to tissue expression and diagnostic features. Using sandwich enzyme-linked immunosorbent assay, plasma levels of enzymes were determined in 15 patients undergoing carotid TEA. Tissue sections were incubated with specific antibodies and fluorescence intensity was analyzed. MMP-9 levels were higher in patients with carotid stenosis versus controls, significantly in those with cerebral lesions at neuroimaging. MMP-9 levels decreased in 93.4% of the patients at 1 month. MMP-2 levels tended to increase 30 days after surgery. TIMP-2 showed no difference. High concentrations of MMP-9 found in patients with carotid stenosis and cerebral lesions suggest that MMP-9 assay could be useful in the evaluation of all carotid lesions to help identify those at highest risk of a neurologic event.

Incorrect Shunt Placement Due to Anatomic Variations of the Aortic Arch During Carotid Endarterectomy: A Rare Cause of Perioperative Ischemia?

To the Editor: Though shunt insertion limits interruption of blood flow during carotid thromboendarterectomy (CTEA), the procedure itself may provoke stroke, usually by air or plaque embolism (1). We report a previously undescribed potential cause of cerebral hypoperfusion during shunting: occlusion of the brachiocephalic trunk during left CTEA due to an anatomic aortic arch variation. A 71-yr-old woman underwent left CTEA under general anesthesia. Insertion of a right radial artery catheter was uneventful. After carotid artery cross-clamping and shunt insertion, we noted loss of the right radial pulse pressure. Her arterial blood pressure, assessed by an oscillometric blood pressure cuff placed on the left arm, remained unchanged. No compression or kinking of the catheter-tubing-transducer system was noticed, and fast-flushing did not show signs of under- or over-damping. Patch angioplasty was completed uneventfully, with normal electroencephalogram tracings. Immediately after shunt removal, her right arterial pressure regained its original shape and correlated with the values assessed by the cuff on the left arm. An anatomic variation of the aortic arch was suspected: subsequent postoperative magnetic resonance angiography confirmed the left common carotid emerging from the innominate trunk (Fig. 1). No postoperative neurological deficiency was noted.Figure 1.: MRA showing the left common carotid emerging from the brachiocephalic trunk. LCCA = left common carotid artery, BCT = brachiocephalic trunk, RCCA = right common carotid artery, RScA = right subclavian artery.Since up to 20% of patients present with aortic arch variation, unintentional occlusion of adjacent vessels and subsequent ischemia may occur during shunt procedures (2). Loss of radial pressure tracing demonstrated subobstruction of the right subclavian artery. We do not know whether the balloon was located in the subclavian artery or more proximal, in the brachiocephalic trunk. As no reflux of blood occurred in the operative field, occlusion of the brachiocephalic trunk seems more likely, potentially causing right cerebral hemisphere hypoperfusion in patients with inadequate redistribution of cerebral blood flow through the circle of Willis. To our knowledge, no case of stroke due to balloon obstruction of the opposite common carotid has been reported, and contralateral stroke remains exceptional. Indeed, during the North American Symptomatic Carotid Endarterectomy Trial (3), only one patient in 1415 awoke with a transient deficit in the contralateral carotid territory. Marc Koch, MD Marco Cristiani, MD Denis Schmartz, MD Department of Cardiothoracic and Vascular Anesthesiology Erasme University Hospital Free University of Brussels Brussels, Belgium [email protected]

Three-Stent Placement for Treatment of Carotid Artery Pseudoaneurysm

Pseudoaneurysm treatment with overlapping stents may be a useful technique to reduce flow and enhance thrombosis in the aneurysmal sac. We treated a pseudoaneurysm of the left carotid artery in a patient with a history of bilateral carotid thromboendarterectomy by placing three stents and overlapping them at the level of the aneurysmal neck. Nine month follow-up revealed almost complete pseudoaneurysm exclusion and patency of the carotid artery.

Surgical management of acute carotid thrombosis after carotid stenting: A report of three cases

We report three cases of symptomatic acute carotid thrombosis occurring after carotid artery stenting (CAS). CASE 1: A patient presented with crescendo transient ischemic attacks on the second day after CAS. Ultrasound images demonstrated incomplete in-stent thrombosis due to plaque protrusion. The urgent surgical procedure consisted of stent removal and carotid thromboendarterectomy. CASE 2: A case of complete thrombosis of a carotid stent occurred 4 days after implantation in a patient with essential thrombocythemia diagnosed by chance. The surgical strategy included stent removal and carotid thromboendarterectomy. CASE 3: Cardiac multiple embolisms in a patient with chronic atrial fibrillation caused concomitant leg ischemia and acute carotid stent occlusion 2 hours after CAS. Cerebral reperfusion was established by embolectomy, without removing the stent. At the same time, the right leg ischemia was resolved by a thromboembolectomy with a Fogarty catheter. These three cases demonstrate that acute thrombosis after carotid stenting can be managed successfully with emergent surgical intervention. Thromboendarterectomy with stent removal or in selected cases, simple thromboembolectomy, can minimize neurologic sequelae in patients suffering from acute post-stenting carotid thrombosis.

Optimising the use of carotid duplex sonography.

We analysed factors influencing diagnostic yield and treatment and their potential for optimising the use of carotid duplex sonography (CDS). Patients referred for CDS were divided into three groups: 1: high likelihood of carotid symptoms, 2: suspected presence of asymptomatic carotid lesions, 3: other indications. Clinical data, the grading of stenosis and the therapeutic consequences were analysed. The efficiency of diagnosis was tested with an algorithm. 344 patients were included. Groups 1, 2 and 3 contained > or = 1 pathological finding in the carotid or vertebral system in 68%, 86% and 55% respectively, whereas high-grade stenoses or occlusions of the internal carotid artery (ICA) were detected in 10.8%, 16% and 3.6% respectively. Age > 50, > 1 risk factor, carotid murmur and concomitant vascular disease were associated with a significantly higher diagnostic yield. Subsequent treatment in groups 1, 2 and 3 involved carotid thromboendarterectomy in 6.4%, 2% and 0.7% respectively and the start of treatment with a platelet aggregation inhibitor in 9%, 30% and 17% respectively. The optimisation algorithm would have saved 21% of CDS scans. Clinical pre-selection criteria determine the diagnostic yield of CDS. The potential for optimisation depends on the treatment regimen chosen for asymptomatic stenoses and secondary prophylaxis.

Assessment of carotid plaque composition in hypertensive patients by ultrasonic tissue characterization: a validation study.

Ultrasonic tissue characterization of epi-aortic vessels may be useful to define the composition of atherosclerotic plaques. Videodensitometry provides a histogram representing the frequency distribution of gray levels corresponding to different compositions of the carotid wall. However, lack of standardization limits the clinical application of this technique. In the present study, the echoreflectivity (ER) pattern of atherosclerotic plaques in vivo was compared with their histological pattern after surgical removal, and the reproducibility of measurement was tested. We studied 19 hypertensive patients with a carotid artery stenosis >or= 70%, eligible for carotid thromboendarterectomy (TEA). Before TEA, all patients underwent standard high-resolution B-mode carotid ultrasound. ER parameters (mean gray level, broad band, skewness, and kurtosis) were obtained in a region of interest selected along the whole plaque, between the intima-blood and the media-adventitia interfaces. The plaques removed during TEA were examined by a histologist and classified into three groups on the basis of fibrous tissue (FT) content: lipidic (FT < 20%), fibrolipidic (20 <or= FT <or= 50%), and fibrous (FT > 50%). Discriminant function analysis was used to evaluate classification efficacy of different histological groups based on ER parameters. Histologically, five lesions were classified as lipidic, six as fibrolipidic and eight as fibrous. Analysis of variance showed significant between group differences in all ER parameters. The combined use of all ER parameters provided correct classification of plaques in 94.73% of cases (P < 0.0001), improving the classification made using single parameters. Intra-observer and inter-observer variabilities (Bland-Altman method) of mean gray level measurements were small. Videodensitometry can discriminate between tissue composition of carotid lesions and complement the quantitative assessment of intima-media thickness by additionally providing a well-reproducible semiquantitative evaluation of vascular wall constituents.