Incidence Of Carotid Artery Stenosis Research Articles

Long-term risk of carotid stenosis and cerebrovascular disease after radiation therapy for head and neck cancer.

Recipients of radiation therapy (RT) for head and neck cancer (HNC) are at significantly increased risk for carotid artery stenosis (CAS) and cerebrovascular disease (CVD). We sought to determine (1) cumulative incidences of CAS and CVD among HNC survivors after RT and (2) whether CAS is associated with a RT dose response effect. This single-institution retrospective cohort study examined patients with nonmetastatic HNC who completed (chemo)RT from January 2000 through October 2020 and subsequently received carotid imaging surveillance ≤2years following RT completion and, in the absence of CAS, every 3 years thereafter. Exclusion criteria included history of known CAS/CVD. Asymptomatic CAS was defined as ≥50% reduction of luminal diameter, symptomatic CAS as stroke ortransient ischemic attack, and composite CAS as asymptomatic or symptomaticCAS. Of 628 patients undergoing curative intent RT for HNC, median follow-up was 4.8years (interquartile range, 2.6-8.3), with 97 patients followed ≥10years. Median age was 61years and 69% of patients received concurrent chemotherapy and 28% were treated postoperatively. Actuarial 10-year incidences of asymptomatic, symptomatic, and composite CAS were 29.6% (95% CI, 23.9-35.5), 10.1% (95% CI, 7.0-13.9), and 27.2% (95% CI, 22.5-32.1), respectively. Multivariable Cox models significant association between asymptomatic CAS and absolute carotid artery volume receiving ≥10 Gy (per mL: hazard ratio, 1.09; 95% CI, 1.02-1.16). HNC survivors are at high risk for post-RT CAS. A dose response effect was observed for asymptomatic CAS at doses as low as 10Gy. Recipients of radiation therapy for head and neck cancer are at significantly increased risk for carotid artery stenosis and cerebrovascular disease. However, carotid artery screening is not routinely performed among head and neck survivors following radiation therapy. In this single-institution retrospective cohort study, patients with head and neck cancer were initially screened for carotid artery stenosis ≤2years following radiation therapy completion, then every 3 years thereafter. The 10-year actuarial incidence of carotid artery stenosis was >25% and stroke/transient ischemic attack >10%. Multivariable analysis demonstrated significant associations between asymptomatic carotid artery stenosis and artery volumes receiving ≥10Gy.

Analysis of Genetic Variants in the Glucocorticoid Receptor Gene NR3C1 and Stenosis of the Carotid Artery in a Polish Population with Coronary Artery Disease.

Background: Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Early diagnosis and elimination of risk factors are crucial for better managing CVDs. Atherosclerosis, whose development might be associated with glucocorticoids (GCs), is a critical factor in the development of carotid artery (CA) stenosis and most other CVDs. Aim: To investigate the association of Tth111I, N363S, and ER22/23EK-NR3C1 polymorphisms and the incidence of CA stenosis. Methods: The study group consisted of 117 patients diagnosed with coronary artery disease (CAD) and CA stenosis and 88 patients with CAD and ruled out CA stenosis. Genomic DNA was extracted from blood, and genotyping was carried out using Tth111I, N363S, and ER22/23EK-NR3C1 polymorphism sequencing. Results: No significant association between studied polymorphisms and the incidence or the severity of CA stenosis in the Polish population with CAD was found. Conclusion: This is the first study that proves that common NR3C1 gene variants do not influence CA stenosis and probably are not associated with atherosclerosis. The search for genes that can act as prognostic markers in predicting CA stenosis is still ongoing.

Revascularization approaches in patients with radiation-induced carotid stenosis: an updated systematic review and meta-analysis.

Ionizing radiation remains a well-known risk factor of carotid artery stenosis. The survival rates of head and neck cancer patients undergoing radiotherapy have risen owing to medical advancements in the field. As a consequence, the incidence of carotid artery stenosis in these high-risk patients has increased. In this study we sought to compare the outcomes of carotid endarterectomy (CEA) vs carotid artery stenting (CAS) for radiation-induced carotid artery stenosis. This study was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Eligible studies were identified through a comprehensive search of PubMed, Scopus and Cochrane Central until July 2020. A random-effects model meta-analysis was conducted, and odds ratios (ORs) were calculated. The I-square statistic was used to assess for heterogeneity. Seven studies and 201 patients were included. Periprocedural stroke, myocardial infarction (MI), and death rates were similar between the two revascularization approaches. However, the risk for cranial nerve (CN) injury was higher in the CEA group (OR, 7.40; 95% CI, 1.58-34.59; I2 = 0%). Analysis revealed no significant difference in terms of long-term mortality (OR, 0.41; 95% CI, 0.14-1.16; I2 = 0%) and restenosis rates (OR, 0.69; 95% CI, 0.29-1.66; I2 = 0%) between CEA and CAS after a mean follow-up of 40.5 months. CAS and CEA appear to have a similar safety and efficacy profile in patients with radiation-induced carotid artery stenosis. Patients treated with CEA have a higher risk for periprocedural CN injuries. Future prospective studies are warranted to validate these results.

Relationship Between Risk Factors and Carotid Artery Stenosis Prevalence in Patients With Lower Extremity Peripheral Arterial Disease

Introduction: One of degenerative disease is atherosclerosis. Peripheral artery disease (PAD) and carotid artery stenosis (CS) broadly covers vascular disease, both of which can be caused by atherosclerosis. Given the general etiology of peripheral atherosclerosis that can occur in different vascular locations, the presence of disease in one place increases the frequency of symptomatic and asymptomatic disease in another. Because both have the same cause, there is a hypothesis that the two are correlated. The purpose of this study was to determine the risk factors associated with carotid artery stenosis (CS) in patients with lower extremity peripheral artery disease (PAD) and to determine the prevalence of carotid artery stenosis (CS) and the thickness of intimal media thickness (IMT) in patients with lower extremity peripheral artery disease (PAD). Method: This research was conducted at Cipto Mangunkusumo General Hospital during February-May 2018. This study was prospective. Data were taken from secondary data based on history and laboratory results, while the degree of stenosis and intimal media thickness were carried out by carotid duplex ultrasound (DUS) with united imaging ultrasound using a probe 8.5 Mhz. The receiver operating characteristic curve was used to assess the best cut point with sensitivity, specificity, positive predictive value, and negative predictive value. Results: A total of 50 subjects with an age range between 49-80 years (63.8 ± 8.8 years), of which there were 31 male males (62%) and 19 females (38%). There was a correlation between hypercholesterolemia and smoking history with the degree of carotid stenosis (p <0.05), while risk factors for the degree of IMT was not found. The prevalence of mild carotid artery stenosis (CS) was 26 (52%), moderate carotid artery stenosis 15 (30%), severe carotid artery stenosis 9 (18%). In comparison, the IMT value in this study obtained 9 (18%) mild IMT, 22 (44%) moderate IMT, and 19 (38%) severe IMT. Conclusion: In patients with severe PAD, the highest incidence of carotid artery stenosis (CS) was in the mild category (52%). The highest rate of intimal media thickness (IMT) was a medium-size IMT (44%). Carotid artery stenosis (CS) was associated with hypertension, diabetes, hypercholesterolemia, smoking, and a family history of atherosclerosis. In statistical analysis, hypercholesterolemia and smoking history had a relationship with the severity of carotid stenosis. Keywords: Atherosclerosis, carotid artery stenosis (CS), carotid duplex ultrasound (DUS), intimal media thickness (IMT), peripheral arterial disease (PAD)

Roles of Nitric Oxide and Prostanoid Mediators in the Adaptation of the Cerebrocortical Blood Flow to Carotid Artery Occlusion

The understanding of cerebral autoregulation has become of notable importance due to the increased incidence of carotid artery stenosis in the elderly population which entails an increased risk of stroke, the 2nd most common cause of mortality worldwide. Many debates, regarding its exact mechanisms, exist in the scientific literature including the role of endothelial and neuronal nitric oxide (NO) synthases (eNOS and nNOS) and prostanoid mediators (PMs). According to our previous observations, eNOS, surprisingly, does not seem to play an important role in the autoregulation of the cerebrocortical blood flow (CoBF) to unilateral common carotid artery occlusion (CAO) (1). In our recent study we aimed to analyze the combined lack of eNOS and nNOS and the role of PMs in cerebrovascular autoregulation by analyzing the changes of CoBF after reducing the cerebral perfusion pressure by unilateral (left) CAO in wild‐type (WT), as well as in eNOS/nNOS double knock‐out (KO) male mice. The role of PMs was tested by indomethacin administration (1 mg/kg, i.p.) and in thromboxane knock‐out (TPR‐KO) male mice. Using the high temporal and spatial resolution of laser‐speckle imaging regional CoBF changes were analyzed after CAO in anesthetized adult male mice. In wild‐type animals CoBF reduction in the left temporal cortex started immediately after CAO, reaching its maximum (−27%) at 6–9 s. Thereafter, CoBF recovered close to the pre‐occlusion level within 30 s indicating the activation of regulatory pathway(s). Interestingly, the frontoparietal cerebrocortical regions also showed CoBF reduction in the left (−17–19%) hemisphere, indicating a stealing effect through pial collateral vessels from the frontoparietal to the more ischemic temporal cortex. Surprisingly, in eNOS/nNOS double KO animals the acute CoBF reduction after CAO was unaltered in all cerebrocortical regions, but the recovery of CoBF was worsened as compared to controls. Indomethacin treatment resulted in a faster recovery in the temporal region, specifically 9–21 s after the occlusion. In TPR‐KO animals, however, the recovery of the CoBF was slightly diminished. These results indicate that (1) the Willis circle alone is not sufficient to provide an immediate compensation for the loss of one carotid artery, (2) the combined lack of eNOS and nNOS impairs only the subacute phase of the recovery after unilateral CAO and (3) indomethacin treatment results in a faster recovery, probably by inhibiting the release of a vasoconstrictor prostanoid, which is not thromboxane A2.Support or Funding InformationEFOP‐3.6.3‐VEKOP‐16‐2017‐00009, OTKA K‐125174, OTKA K‐112964, NVKP‐16‐1‐2016‐0042

Retinal artery occlusion does not portend an increased risk of stroke

ObjectiveThe aim of this study was to determine the subsequent risk of stroke after a diagnosis of retinal artery occlusion (RAO). We hypothesized that the risk would be low and comparable to that of the general population. RAO is relatively rare and often incorrectly diagnosed. We believe our institution is in a unique position to investigate this relationship with both a high-volume eye center and vascular laboratory. MethodsThis was a retrospective, single-institution review of 221 patients diagnosed with RAO from 2004 to 2018, confirmed with fluorescein angiography. Demographics, comorbidities, imaging of the carotid arteries, and prospective events, such as stroke, myocardial infarction (MI), and death, were recorded. Time to first stroke, first MI, and death was estimated using Kaplan-Meier estimation separately and as a composite end point. ResultsThere were 221 patients identified with a confirmed diagnosis of RAO. The mean age in the cohort was 66.1 years; 53% of patients were male, and 29% were diabetic. Median length of follow-up was 2.2 years. Five patients (2.3%) had a documented stroke; four of the five strokes occurred at the time of RAO, with one that was contralateral occurring at 1.2 years. There were eight MIs (3.6%) in the cohort, two of which resulted in death. Twenty-two patients (10%) experienced a stroke, MI, or death. There were 141 (63.8%) patients who had carotid imaging performed, of whom 20 (14.2%) were found to have >50% stenosis. ConclusionsThe rate of stroke in patients with confirmed RAO was 2.3%; however, excluding concurrent ischemic events, the risk was <1%. The incidence of carotid artery stenosis >50% was 14.2%. The authors conclude that the risk of stroke after confirmed RAO is lower than previously reported and comparable to prior population-based studies of all at-risk adults.

The Risk of Carotid Stenosis in Head and Neck Cancer Patients After Radiation Therapy

Retrospective single-center review of head and neck cancer (HNC) patients who underwent carotid duplex ultrasound (DU) after radiation therapy (RT) between January 2000 and May 2016. Risk of carotid stenosis (>50%) in 366 HNC patients was 34% 8 years after RT. Multivariate analysis showed that diabetes was predictive of time to carotid artery stenosis but not RT dose. The high incidence of carotid artery stenosis after RT warrants carotid artery screening after RT in HNC patients. Although stenosis was not related to RT dose, the limited mean follow-up of 4 years in this series may be too short to detect a dose response effect.

Radiation-induced carotid artery lesions.

To review the current aspects of knowledge related to the risk of cerebrovascular events in patients receiving head and neck radiotherapy. Aliterature search was performed in PubMed. Papers meeting selection criteria were reviewed. We provide an update on the problem by identifying key studies that have contributed to our current understanding of the epidemiology, radiologic features, pathogenesis, and treatment of the disease. The incidence of carotid artery stenosis ranged from 18 to 38% in patients who underwent radiotherapy for head and neck cancer versus from 0 to 9.2% among the nonirradiated patients. Neck irradiation increases the intima-media thickness of the carotid artery wall. These changes are the earliest visible alteration in the carotid wall and are also detected with color Doppler ultrasonography. Endovascular treatment with acarotid angioplasty and stenting is the first-line treatment for most symptomatic patients. Radiation-induced atherosclerosis is adifferent and accelerated form of atherosclerosis, which implies amore aggressive disease with adifferent biologic behavior. The disease is characterized by ahigh rate of carotid artery stenosis compared to those observed in nonirradiated control group patients. To prevent the risk of stroke, surveillance and imaging with ultrasonography should enable detection of severe stenosis. Endovascular treatment with acarotid angioplasty and stenting has been proposed as an attractive and minimally invasive alternative for some radiation-induced stenoses.

Revascularization of radiation-induced carotid artery stenosis with carotid endarterectomy vs. carotid artery stenting: A systematic review and meta-analysis.

The incidence of carotid artery stenosis after head and neck radiation is anticipated to rise due to the increasing survival of patients with head and neck malignancies. It remains unclear whether carotid artery stenting (CAS) or endarterectomy (CEA) is the best treatment strategy for radiation-induced carotid artery stenosis. This study was performed according to the PRISMA and MOOSE guidelines. Eligible studies were identified through a comprehensive search of PubMed, Scopus and Cochrane Central until July 20, 2017. A meta-analysis of random effects model was conducted. The I-square statistic was used to assess for heterogeneity. Five studies and 143 patients were included. Periprocedural stroke, myocardial infarction (MI) and death rates were similar between the two revascularization approaches. However, the risk for cranial nerve (CN) injury was higher in the CEA group (OR: 7.09; 95% CI: 1.17-42.88; I2 = 0%). CEA was associated with lower mortality rates after a mean follow-up of 50 months (OR: 0.29; 95% CI: 0.09-0.97; I2 = 0%). No difference was identified in long-term restenosis rates between CEA and CAS. Patients with radiation-induced carotid artery stenosis can safely undergo both CAS and CEA with similar risks of periprocedural stroke, MI and death. However, patients treated with CEA have a higher risk for periprocedural CN injuries and a lower risk for long-term mortality.

Carotid Angiographic Profile in Patients with Coronary Artery Disease

Background: This study was conducted with an aim of assessing the angiographic incidence of carotid artery stenosis (CAS) in patients undergoing coronary angiography for the diagnosis of coronary artery disease (CAD). Methods: This single centre study included 50 patients with stable CAD or acute coronary syndromes, undergoing coronary angiography for diagnostic or therapeutic indications, who gave consent for concomitant carotid digital subtraction angiography (DSA). Significant CAD was defined as ≥ 50% diameter stenosis in at least one major coronary artery or its first order branches, and was categorized as single vessel disease (SVD), double vessel disease (DVD), or triple vessel disease (TVD) according to number of vessels involved. Significant CAS was defined as a diameter stenosis of ≥50% in the common carotid artery, the carotid bifurcation, or the internal carotid artery. For statistical analysis, patients were divided into two groups i.e. patients without or with CAS. Patient characteristics in these groups were then analysed and compared to each other. Results: The mean age of study group was 58.72 ± 9.03 years. Out of 50 patients studied 33 (66%) were males and 17 (34%) were females. Risk factors included hypertension, smoking, diabetes mellitus and dyslipidemia in 82%, 50%, 48% and 28% patients respectively. CAD was present in 62% patients; with 24%, 14% and 24% patients having SVD, DVD and TVD respectively. CAS was present in 10 (20%) patients, all of whom had TVD on coronary angiography (p≤0.0001). Patients with CAS were more likely to be older than those without CAS (p=0.065). Additionally, 80% of patients with CAS were males and all of them were hypertensive. Conclusion: Significant CAS is found in substantial proportion of patients with CAD, especially multi vessel disease. A strategy of concomitant carotid DSA at the time of coronary angiography may allow superior risk stratification and better planning of management in these patients. Key words: Carotid artery stenosis, Carotid angiography, Coronary Artery Disease.

Ocular Arterial Occlusive Disorders and Carotid Artery Disease

To compare prevalence of carotid artery disease and its various types of lesions in different types of ocular arterial occlusive disorders. Cohort study. 614 consecutive patients (728 eyes) with ocular arterial occlusive disorders. At first visit, all patients had a detailed ophthalmic and medical history, comprehensive ophthalmic evaluation, and carotid artery evaluation (by Doppler/angiography) on the side of ocular arterial occlusion, and echocardiography. The same ophthalmic evaluation was performed at each follow-up visit. Ocular arterial occlusive disorders were divided into central (CRAO) and branch (BRAO) retinal artery occlusion, ocular ischemic syndrome (OIS), non-arteritic anterior ischemic optic neuropathy (NA-AION) and amaurosis fugax (AF). Carotid artery and echocardiographic abnormalities, and incidence of transient ischemic attack (TIA)/stroke and myocardial ischemia. The study consists of a cohort of 266 eyes with NA-AION, 203 with CRAO, 127 with BRAO, 80 with OIS and 52 with AF. Carotid artery stenosis on the involved side was worse in AF and OIS compared to BRAO, CRAO, and NA-AION (p<0.0001). Presence of carotid artery plaques on the involved side was significantly higher in OIS, AF, and CRAO compared to NA-AION (p=0.002, p=0.003, and p=0.0003, respectively). Echocardiography revealed an embolic source in 61% of CRAO and 53% of BRAO compared to only 3% of NA-AION patients (p<0.0001). TIA/stroke before or after onset of ocular condition occurred in 17% of OIS, 11% of AF, 7% of CRAO, 6% of NA-AION, and 3% of BRAO patients. Kaplan-Meier estimate of the incidence of TIA /stroke within 3 months after onset was 6% (95% CI: 2%, 17%) for OIS, 3% (95% CI: 0.4%, 19%) for AF, and 1% (95% CI: 0.3%, 4.1%) for CRAO. Report of myocardial ischemia before or after onset of ocular condition was 52% in AF, 22% in OIS, 22% in BRAO, 21% in CRAO, and 6% in NA-AION patients. The incidence of carotid artery stenosis and plaques, cardiac embolic source, TIA/stroke and myocardial ischemia differ among various ocular arterial occlusive disorders. The role of embolism and hemodynamic disturbances caused by carotid artery disease in these disorders is discussed.

ISCHEMIC HEART DISEASE

Objectives: To find the correlation between the non-alcoholic fatty liver disease(NFALD) and ischemic heart disease. Study Design: Retrospective cross-sectional study.Period: May 2014 to Nov 2014. Setting: CPE Institute of Cardiology. Material and methods:One hundred and thirty five participants were incorporated in the study. In Group I; patientswere with NAFLD and in group II; patients were without NAFLD. Data was Analyzed using SPSSV20 software. Results: Mean age in NAFLD group was 52.0+02.6 years and in without NAFLD53.0+1.89 years. There were 73.2 % males in NAFLD group. Incidence of Family history anddiabetes was higher in NAFLD group. The incidence of carotid artery stenosis was 4 (9.7%) inNAFLD group versus 6 (6.3%) in without NAFLD group. we also found a significantly higherincidence of triple vessel and left main stem disease in NAFLD group, it was 34 (80.87%) and3 (7.31%) in NAFLD group versus 9 (9.7%) and 2 (2.12%) in without NALD group respectively.Conclusion: Non-alcoholic Fatty liver Disease has a strong correlation with ischemic heartdisease.

Aktueller Stand der Carotisstent-Implantation 2012

Stenosis of the internal carotid arteries is one of the leading causes of ischemic stroke. With increasing age of the general population, both physicians and patients have to increasingly face that problem, which is often found accidentally for example in the context of a routine checkup examination. In patients over seventy years, the incidence of carotid artery stenosis is about 15%. Principally, there are three options for the treatment of carotid artery stenosis: 1) best medical treatment, 2) operative revision by endarterectomy and 3) interventional therapy via stent implantation. Based on technical development and new scientific data, there has been tremendous progress of all three treatment strategies in the last few years. Therefore, the results of prior trials must not necessarily be considered when choosing a treatment option for the patient. The choice of therapy for the individual patient must take into account a number of criteria, such as grade of stenosis, symptoms, patient age, concomitant disease, anatomical conditions and patients' preference. Recently, a number of clinical trials have been performed to compare operative versus interventional treatment. The results of these studies led to some answers, but there are questions remaining which need to be clarified. The present article gives a brief overview and comment on the current status of treatment strategies of internal carotid artery stenosis based on the recent literature.

Contemporary incidence and risk factors for carotid artery disease in patients referred for coronary artery bypass surgery.

BackgroundIn the past decade, there has been an increase in the amount of patients with medical co-morbidities referred for coronary artery bypass surgery (CABG). Significant carotid artery disease in patients undergoing CABG procedures increases the risk of neurological complications. We review the results of routine carotid screening in patients undergoing CABG to determine the contemporary incidence and risk factors for carotid artery disease.MethodsBetween 2008 through 2010, 673 patients were referred for isolated coronary artery bypass surgery at a single institution. Patients were identified through a systematic review of The Department of Cardiothoracic Surgery Society of Thoracic Surgery Outcomes Database. A retrospective analysis of prospectively collected demographic, clinical data and outcomes were performed. All patients with screening preoperative carotid duplex were reviewed. We defined the degree of carotid disease as: none to mild stenosis (<50%), moderate stenosis (50-69%), severe stenosis (70-99%). Multivariate analysis was performed to identify risk factors.Results559 (83%) patients underwent screening preoperative carotid ultrasonography prior to CABG. The incidence of carotid artery disease (>50% stenosis) was 36% with 18% unilateral moderate disease, 10% bilateral moderate and 8% severe disease. Risk factors associated with carotid artery disease included: advanced age, renal failure, previous stroke, peripheral vascular disease, left main coronary artery disease, and previous myocardial infarction.ConclusionsThere is a significant incidence of carotid artery stenosis in patients referred for CABG. Routine screening will identify patients with carotid artery disease and may reduce the risk of postoperative stroke.

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The incidence of carotid artery stenosis is debatable based upon the findings of the NASCET, ECST and ACAS reports. We generally determine the incidence of stenosis in patients through the limited directions by angiographic methods. However, there are likely some shortcomings of this evaluation procedure with the pathogenesis of carotid artery stenosis. The importance of the carotid artery wall has recently been established. In general, these characteristics can be examined using ultrasound sonography. While the degree of ulceration, endothelial condition, lipid pool, thin cap and plaque intensity can ordinarily be examined, we are especially attempting to detect the existence of neovascularization in plaque. The importance of neovascularization in atherosclerosis has been recognized. Neovascularization is one of the pathological factors introducing plaque hemorrhage and rupture, which can result in carotid artery occlusion and artery-to-artery embolism. Pulse inversion harmonic image (PIHI) using pulse inversion to eliminate and strengthen the harmonic frequency is more effective than conventional harmonic imaging. We can detect a tissue perfusion by contrast sonographic imaging with PIHI, and its clinical application has already been reported. Consequently, we use this method to test for cardiac infarction, liver tumor, brain tumor and cerebrovascular diseases. We examined carotid artery wall perfusion (CAWP) and the rule of neovascularization within the plaque by this method. The routes of vascular wall feeding are as follows: 1) Luminal diffusion feeds the vascular wall from the endothelium to the inner part of the medium and 2) the vasa vasorum feeds it from the adventitia to the outer part of the medium. Consequently, neovascularization does not occur at the former vascular wall region. However, some plaque is resistant to neovascularization. As a result, we attempt to detect plaque using this method, and we have already described a classification of CAWP findings. Type I exhibits no perfusion and lack of neovascularization. Type II exhibits partial perfusion of CAWP that is indicative of mild neovascularization. Type III exhibits multiple perfusion of CAWP that is indicative of moderate neovascularization. Type IV exhibits general perfusion of CAWP that is indicative of neovascularization of the whole plaque. Type III and IV are usually observed in patients with intramural hemorrhage or artery-to-artery embolism. We propose the following mechanism for plaque development. The beginning of atherosclerosis→in some, neovascularization on the plaque development→The small neovasculature is vulnerable. Consequently, damage can occur by mechanical stimulation→then intramural hemorrhage can occur→resulting in the onset of ischemic symptoms as the development of stenosis or embolism. We intend to examine the incidence of carotid artery stenosis with or without neovascularization and carefully observe such patients because of the rapid development of plaque, plaque rupture, occlusion of main extracranial arteries and artery-to-artery embolism.

Assessment of the efficacy of noninvasive screening for patients with asymptomatic neck bruits.

Several recent clinical trials have shown that endarterectomy is efficacious in patients with asymptomatic carotid artery stenosis. The purpose of this study was to evaluate the effectiveness of various test strategies for screening and diagnosing carotid artery disease. We constructed a model of the natural history of carotid artery disease using literature-based estimates of the prevalence and incidence of carotid artery stenosis and associated morbidity and mortality. Markov cohort simulation was used to estimate the mean quality-adjusted life years and monetary costs associated with various management strategies. Screening is cost-effective in the baseline model. Key parameters affecting the efficacy of screening are prevalence of operable lesions, benefit of surgery, surgical complication rates, quality of life with stroke, rate of stenosis progression, and excess morbidity and mortality. Asymptomatic patients with carotid bruits may benefit from screening if the prevalence rate is > or = 20%, the benefits and risks associated with surgery are similar to those observed in the Asymptomatic Carotid Atherosclerosis Study, and the quality of life with stroke is considerably lower than the quality of life without stroke. Ultrasound followed by three-dimensional time-of-flight MR angiography, if indicated, is a promising test strategy.

Incidence of carotid artery stenosis by carotid two-dimensional and color doppler flow imaging in patients with cerebral infarction

Incidence of carotid artery stenosis by carotid two-dimensional and color doppler flow imaging in patients with cerebral infarction