A major study published in the Lancet Neurology, funded by the Medical Research Council (MRC) and the Stroke Association, has found that stenting in the carotid artery (in the neck) is as safe as carotid artery surgery at reducing stroke risk in some patients.
The research, which was part of the International Carotid Stenting Study (ICSS), reveals that stenting is equally as safe as surgery in patients who show few signs of changes to brain tissue (known as white matter lesions) in a brain scan. However, patients whose brain scans do reveal changes to brain tissue, potentially caused by aging or conditions such as high blood pressure, should not be treated by stenting. The study, which was run from University College London, highlights the importance of carrying out brain scans in patients undergoing either procedure in order to determine which is most suitable.
One in five strokes are caused by narrowing of the carotid arteries due to a build-up of fatty deposits on the artery walls. However, the risk of stroke can be reduced by surgery to clean out the deposits or through stenting to widen the artery. Both procedures carry risks and in a minority of cases they can cause a stroke at the time of treatment. Earlier results from the ICSS have shown that although stenting is less invasive than surgery, the associated risks of stroke are higher.
This study looked for white matter lesions in the brain scans of patients taken before they underwent either surgery or stenting. One in ten patients with a greater than average number of white matter lesions had a stroke within 30 days of stenting treatment – three times higher than the risk of stroke after surgery. In contrast, in patients with less white matter damage, the risk of stroke was much lower and the same after both stenting and surgery.
Professor Martin Brown, the Chief Investigator of ICSS comments;
“The results of this trial demonstrate convincingly for the first time that the severity of white matter damage shown on CT or MRI brain scans should be taken into account when patients are offered treatment for carotid artery narrowing.
“Until now there has not been any conclusive way to select patients for stenting rather than surgery, although it was known that stenting was riskiest in older patients. This research suggests that patients with less than average amounts of white matter damage can be safely treated with stenting rather than surgery, but surgery should be the preferred treatment in patients with more extensive white matter damage on a brain scan.”
Dr Clare Walton, Research Communications Officer at the Stroke Association says; “The results of this study are encouraging and demonstrate that stenting could be as safe as preventative surgery in some patients.
“Stenting is less invasive and traumatic than surgery. It is therefore likely that it will be the first choice of treatment for many patients and we’re pleased that it could be an option for more people. The results of this study also highlight the importance of carrying out brain scans to establish previous damage or changes to the brain before any type of procedure is undertaken. We look forward to the results of further research in this area.”
ICSS was run from UCL (University College London) and included 50 hospital centres from Europe, Canada, Australia and New Zealand. 14 hospitals in the UK took part. Patients were recruited if they were found to have significant narrowing of a carotid artery that had already caused a stroke from which the patient had made a good recovery. Half the patients were randomly allocated treatment of the carotid narrowing by stenting and half were allocated surgery and were then seen regularly to find out how they got on.
1. Professor Martin Brown is Professor of Stroke Medicine at the UCL Institute of Neurology, University College London and Consultant Neurologist at the National Hospital for Neurology and Neurosurgery and University College Hospital.
2. The paper will be published online in the Lancet Neurology on 12th July 2013 with the following title:
Effect of white-matter lesions on the risk of periprocedural stroke after carotid artery stenting versus endarterectomy in the International Carotid Stenting Study (ICSS): an analysis of data from a randomised trial
3. The views expressed in this publication are those of the authors and not necessarily those of the MRC, NHS, NIHR, Stroke Association or the Department of Health.
4. A stroke is a brain attack, which happens when the blood supply to the brain is disrupted, caused by a clot or bleeding in the brain. It is the leading cause of severe adult disability in the UK. Over 150,000 people have a stroke every year in the UK, that’s one every five minutes. More than a million people live with the effects of stroke and over half of them rely on daily support from carers because of disability.
5. Stroke Association is a charity. We believe in life after stroke and we’re leading a community of people to change the world for people affected by stroke. We work directly with stroke survivors and their families and carers, with health and social care professionals and with scientists and researchers. We campaign to improve stroke care and support people to make the best recovery they can. We fund research to develop new treatments and ways of preventing stroke. The Stroke Helpline (0303 303 3100) provides information and support on stroke.
6. The Medical Research Council has been at the forefront of scientific discovery to improve human health. Founded in 1913 to tackle tuberculosis, the MRC now invests taxpayers’ money in some of the best medical research in the world across every area of health. Twenty-nine MRC-funded researchers have won Nobel prizes in a wide range of disciplines, and MRC scientists have been behind such diverse discoveries as vitamins, the structure of DNA and the link between smoking and cancer, as well as achievements such as pioneering the use of randomised controlled trials, the invention of MRI scanning, and the development of a group of antibodies used in the making of some of the most successful drugs ever developed. Today, MRC-funded scientists tackle some of the greatest health problems facing humanity in the 21st century, from the rising tide of chronic diseases associated with ageing to the threats posed by rapidly mutating micro-organisms. The MRC Centenary Timeline chronicles 100 years of life-changing discoveries and shows how our research has had a lasting influence on healthcare and wellbeing in the UK and globally, right up to the present day.