Cerebrovascular diseases
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Cerebrovascular diseases · Jan 2004
International carotid stenting study: protocol for a randomised clinical trial comparing carotid stenting with endarterectomy in symptomatic carotid artery stenosis.
Carotid stenting avoids general anaesthesia, cranial nerve injury and the discomforts of surgical treatment of carotid stenosis. A systematic review of the randomised trials showed no overall difference in the major risks of endovascular treatment for carotid stenosis compared with surgery, but the confidence intervals were wide and both methods carried a significant risk of stroke. The use of protection devices appears to improve the safety of endovascular treatment, but there are little randomised data available about long-term outcomes. We have therefore set up an international, multicentre, randomised, controlled, open, prospective clinical trial, namely the International Carotid Stenting Study (ICSS), also known as CAVATAS-2. The objectives of the ICSS are to compare the risks, benefits and cost-effectiveness of a treatment policy of referral for carotid stenting compared with referral for carotid endarterectomy. ⋯ The ICSS protocol incorporates a number of novel features to ensure patient safety, including the concept of probationary centres, proctoring of inexperienced investigators and monitoring of individual centre results on an ongoing basis. The protocol is also designed to mirror routine clinical practice as far as possible, so that the results will be widely applicable and relevant to determining the place of carotid stenting in clinical practice in the future.
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Cerebrovascular diseases · Jan 2004
ReviewNeuroprotection in cerebral ischaemia: facts and fancies--the need for new approaches.
'Neuroprotection' is a term used to describe the putative effect of interventions protecting the brain from pathological damage. In occlusive stroke, the concept of neuroprotection involves inhibition of a cascade of pathological molecular events occurring under ischaemia and leading to calcium influx, activation of free radical reactions and cell death. This article will summarize neuroprotection trials to date, some facts and fancies about neuroprotection, ischaemic pathophysiology and possible reasons for the apparent failure of human neuroprotective stroke trials. ⋯ In the acute stage of occlusive stroke, moderate reduction of blood flow results in a 'penumbra' of brain cells, often surrounding a core infarct, in which brain cells survive for a few hours but gradually die if reperfusion is not established. Increased knowledge of the complex pathophysiology in acute ischaemic stroke has led to the development of a great number of candidates for neuroprotective interventions. Many neuroprotective agents have proven efficacious in animal models, but so far no human study has shown a statistically significant benefit in patients with acute ischaemic stroke on primary endpoint measures. Some neuroprotective agents show beneficial effects on post hoc analyses, and some studies are still ongoing. FANCIES: In the early years of neuroprotective studies in stroke, it was thought that a drug with almost no adverse effects could be given by ambulance staff on the way to hospital and induce a clinically significant effect on outcome. Since there were only benefits and no risks, diagnostic skills by neurologists and neuroradiological evaluations would no longer be required. WHY HAVE NEUROPROTECTIVE AGENTS FAILED IN HUMAN STROKE TRIALS? There are several possible explanations why neuroprotective trials have been unable to prove an effect in addition to the eventuality that the basic concept is wrong. The effects of neuroprotective agents on infarct size are time dependent, and treatment has often been initiated much later than in successful experimental stroke models. Insufficient doses of the drugs and slow availability of the drug at the target area may be other explanations. Too small sample sizes in trials and imbalance of prognostically important baseline variables are examples of shortcomings in trial methodology. WHAT CAN BE DONE? FUTURE NEW APPROACHES: IN ANIMAL MODELS, preclinical testing of neuroprotective candidates should be standardized. Conventional stroke models with young and healthy animals may be replaced by older animals with common co-morbidity such as atherosclerosis. Highly effective new neuroprotective agents need to be discovered, and combination therapies should be tried. IN CLINICAL TRIALS, the greatest chances of success may be with neuroprotective concepts involving mechanisms in both ischaemic and reperfusion pathophysiology, in combination with a thrombolytic therapy protocol. Neuroprotective agents, possibly combinations of agents, should preferably approach several of these mechanisms. Treatments should be initiated early, at least within 3 h after stroke onset, by an intravenous route. The selected compound(s) should easily pass the blood-brain barrier. Neuroprotective agents shown to be highly effective in stroke models should be preferred, and doses used experimentally should be used also in the clinical setting. Trials should use randomization techniques, which reduce imbalances of prognostically important baseline variables, and the estimated sample size of a trial should be based on expectations of a modest clinical effect.
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Cerebrovascular diseases · Jan 2004
Comparative StudyDoes treatment modality of intracranial ruptured aneurysms influence the incidence of cerebral vasospasm and clinical outcome?
Cerebral vasospasm is the most common cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH). This study is designed to determine whether the incidence of symptomatic vasospasm and the overall clinical outcome differ between patients treated with surgical clipping compared with endovascular obliteration of aneurysms. ⋯ Symptomatic vasospasm and ischemic infarction rate seem comparable in both groups, even for patients with better clinical and radiological admission grades. There is no significant difference in the overall clinical outcome at the long-term follow-up between both groups.
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Cerebrovascular diseases · Jan 2004
Quality of life after treatment of unruptured intracranial aneurysms by neurosurgical clipping or by embolisation with coils. A prospective, observational study.
Relatively high rates of complications occur after operation for unruptured intracranial aneurysms. Published data on endovascular treatment suggest lower rates of complications. We measured the impact of treatment of unruptured aneurysms by clipping or coiling on functional health, quality of life, and the level of anxiety and depression. ⋯ In the short term, operation of patients with an unruptured aneurysm has a considerable impact on functional health and quality of life. After 1 year, recovery occurs but it is incomplete. Coil embolisation does not affect functional health and quality of life.
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Cerebrovascular diseases · Jan 2004
Clinical TrialHyperdense middle cerebral artery sign: can it be used to select intra-arterial versus intravenous thrombolysis in acute ischemic stroke?
Stroke patients with a hyperdense middle cerebral artery sign (HMCAS) may respond less favorably to intravenous (IV) thrombolysis. ⋯ In a small sample, patients with HMCAS appeared to respond better to IA than IV rtPA.