View clinical trials related to Carotid Stenosis.
Filter by:Microembolization is commonly associated with carotid artery stenting (CAS), but our understanding of subclinical microembolization is superficial. Through collaborative effects of multidisciplinary team-experts, novel approaches, and longitudinal evaluations, we hope to better understand the clinical significance and long-term cognitive effects of microemboli. This proposal may change our current clinical practice by providing a better outcome measure for carotid interventions and improving outcomes of CAS procedures through risk factor stratification. Our central hypothesis is that development of subclinical microemboli is associated with decline in cognitive function following CAS and that the risk of development of microemboli themselves is associated with patient- and procedure-related factors. We hope that this prospective study will help to clarify these important issues in the era of rapidly evolving percutaneous interventions.
Remote limb ischemic preconditioning (RIPC) has neuro-protective and anti-inflammatory effects on ischemia- reperfusion injury. As the extent of its effect is unknown, the investigators will use clinical outcome, serum biochemical markers and brain magnetic resonance imaging (MRI) to determine whether RIPC has neuro-protective and anti-inflammatory effects on patients undergoing carotid artery stenting.
Patients suffering from symptomatic carotid artery stenosis, transient ischemic attacks (TIAs), amaurosis fugax or stroke receive either Revacept (single dose) plus antiplatelet monotherapy or monotherapy alone. Patients receive a single dose of trial medication by intravenous infusion for 20 minutes. Patients are followed up one and three days after treatment, at 3 months and by a telephone interview at 12 months.
The aim of the project is to demonstrate a fibrinolytic effect of sonothrombolysis (continual transcranial Doppler monitoring) using 2 MHz diagnostic probe on the reduction of risk of brain infarctions due to the activation of endogenous fibrinolytic system during carotid endarterectomy (CEA) and carotid stenting (CS). 240 patients indicated for CEA (120 patients) and CS (120 patients) will be enrolled into the study in order to demonstrate a twenty-percent risk reduction of number and volume of brain infarctions detected using MRI examination 24 hours after CEA or CS in 5% level of significance. Patients will be randomized - subgroup 1 will undergo a 60minute non-diagnostic TCD monitoring during CEA or CS, subgroup 2 will undergo interventions without TCD monitoring. The second aim is to compare number of brain infarctions detected using MRI between CEA and CS patients. Confirmation of the investigators hypothesis that sonothrombolysis is able to activate endogenous fibrinolytic system during CEA or CS with consecutive reduction of the number and volume of brain infarcts, can lead to the increase of the safety of CEA and CS in patients with internal carotid artery stenosis. The investigators can presume that up to 50% of patients indicated for CEA or CS can be treated using these methods in the future. In the Substudy "Risk of brain infarction after carotid endarterectomy and stenting" the the risk of asymptomatic and symptomatic brain infarctions, changes in cognitive functions, as well as morbidity and mortality at 30 days between patients with symptomatic and asymptomatic severe ICA stenoses undergoing elective CEA and CAS will be compared. The sample size of the Substudy was based on an expected 80% difference of new ischemic lesions on DWI-MRI between CEA (estimated prevalence, 30%) and CAS (54%). Pre-study calculations showed that a minimum of 73 patients in each group was needed to reach a significant difference with an alpha value of 0.05 (two-tailed) and a beta value of 0.8 assuming that 15% of subjects would be lost to follow-up or refuse to participate in the study.
Assess device performance data from subjects undergoing patch angioplasty of the carotid artery following carotid endarterectomy using the CorMatrix ECM for Carotid Repair.
As endovascular procedures become more complex, there is a growing need for 3D image overlay to assist with device guidance and placement. Currently, a 3D image is typically created intra-operatively using 3D rotational angiography (3D-RA) or cone-beam CT (XperCT). This 3D image may then be overlaid on live fluoroscopy to provide 3D guidance information (Dynamic 3D Roadmapping). Philips Healthcare multimodality overlay products allows registration of a pre-acquired MR/CT or 3D rotational image to live fluoroscopy.
Patients scheduled for carotid endarterectomy undergo preoperative imaging to assess vulnerable plaque. The imaging modalities include (in various combinations at different study sites) 3-dimensional ultrasound, PET/CT imaging with fluorodeoxyglucose, MRI (3T)with gadolinium, and contrast ultrasound for assessment of neovascularity of plaques. At surgery the carotid endarterectomy is carried out with en bloc removal of the specimen, which is scanned and stained and assembled into 3D histology.
Patients with rheumatoid Arthritis (RA) and Ankylosing Spondylitis (AS) are at greater risk of developing cardiovascular disease. The reason(s) for this have not been well investigated, but there is a general understanding that systemic inflammation plays a part in the increased cardiovascular morbidity and mortality. In spite of the increased risk in these patients, they have not been included as a high risk patient group in cardiovascular prevention guidelines. The investigators have carried out a cardiovascular study of RA and AS patients, as well as patients with arthritis for the first time. The investigators have demonstrated cholesterol plaques in the carotid artery in some of these patients. Plaques in the carotid artery represent a risk for development of cerebral stroke and are significantly associated with myocardial infarction. These plaques, which are asymptomatic and do not cause haemodynamically significant narrowing, diameter reduction (i.e. operation is not indicated), are vascular atheromatous disease. Therefore, according to prevailing cardiovascular guidelines (SCORE 2007), these patients shall have secondary prevention with a lipid lowering agent with the LDL-cholesterol goal of 1.8 mmol/L and HDL-cholesterol > 1.0 mmol/L for men and > 1.1 mmol/L for women. Statins are cholesterol-lowering drugs, and have been shown to reduce the risk of cardiovascular disease significantly. In addition, reduction in the size of coronary plaques has been induced by statins, when the LDL has been reduced to 1.6-1.8 mmol/l. Plaques in the carotid or coronary arteries have not previously been treated and characterized in patients with RA, AS and other inflammatory forms of arthritis. The aim of this study is to treat patients with cholesterol plaques in the carotid artery with cholesterol-lowering medication, in the form of Rosuvastatin for 18 months, and characterize the effects on the plaques in the carotid and coronary arteries. In addition, the investigators want to clarify the connection between plaques in the carotid and coronary arteries in patients with RA, AS and other inflammatory forms of arthritis.
Carotid artery plaques are known to cause stroke. Cognitive impairment is an insidious but poorly understood problem in patients with carotid plaques. Cognitive function describes how people perform mental processes such as thinking, learning and problem solving. Asymptomatic carotid plaques may affect 1 million Veterans who may be at risk for cognitive impairment. In this study, the investigators will uncover the extent of cognitive impairment in Veterans with carotid stenosis who are currently labeled "asymptomatic". Programs to prevent or mitigate cognitive impairment will depend on identifying the mechanisms by which this occurs. The investigators will use sophisticated 3D imaging techniques developed by the group to measure the structure and composition of plaques, number of particles breaking off from them, blood levels of chemicals that could disrupt them, and blood flow restriction to the brain from them. This will help identify patients at risk for cognitive impairment who may benefit from preventative measures and improve selection of patients to decrease unnecessary surgical procedures.
Subjects referred for a routine CTA (computed tomography angiography) or MRA (magnetic resonance angiography) will be invited to participate in the study and subjects will be involved in the study for between 2 and 12 days. Two to three visits to the study doctor will be required. This study will compare the diagnostic results of Gadobutrol enhanced MRA images with MRA images taken without contrast agent using images from a CTA as the standard of reference, which may have been performed up to 60 days prior to enrolment. If a CTA has not been performed in this prior time period, a CTA is required for the study. MRA and CTA images will be collected for an independent review (blinded read).