颈动脉内膜切除术对中风具有长远效果
NEW YORK (Reuters Health) - Surgery to clear severely blocked neck arteries that deliver blood to the brain is proven to reduce the short-term risk of stroke. Now researchers report that the benefits of the procedure, carotid endarterectomy, are long lasting.
A study called the North American Symptomatic Carotid Endarterectomy Trial (NASCET) that began in 1987 was designed to see whether endarterectomy could prevent stroke in people with a partially to nearly completely blocked carotid artery.
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While everyone enrolled in the study received medical treatment for stroke risk factors like high blood pressure, high blood sugar and high cholesterol levels, half of the participants also underwent the artery-clearing surgery, according to the study's lead investigator, Dr. Henry J.M. Barnett, of the John P. Robarts Research Institute in Ontario, Canada.
By 1991, it became clear that surgery prevented strokes in people with the most severely blocked arteries--70% to 99% blocked--who had symptoms like face numbness, difficulty speaking and dizziness, Barnett told Reuters Health in an interview. The risk of stroke was about 17% lower in patients treated with surgery, according to Barnett.
, http://www.100md.com
“For severe patients, the study was over.” he said. Since withholding potentially lifesaving treatment would be unethical, all participants in the non-surgery group were given the opportunity to have the surgery.
Barnett said that about half of the group had endarterectomy right away, while others either chose not to have surgery or were so unhealthy that the risks of surgery would have outweighed its potential benefits.
In the September issue of Stroke: Journal of the American Heart Association, Barnett and his colleagues provide an update on the long-term effects of endarterectomy, both in patients who underwent the surgery at the start of the study, as well as those who had surgery in 1991 or later.
, http://www.100md.com
“Endarterectomy proved durable in the long term and reduced the risk of stroke sufficiently so that only five patients need to be treated to prevent one stroke in three years.”the researchers write.
“This is a procedure that lasts.” according to Barnett. “It's not just something that will benefit you for a few months.”
People first treated with drugs alone who later underwent surgery benefited, although the risk of stroke was not reduced as much as in those who had endarterectomy at the start of the study, the study authors explain.
, 百拇医药
Three years after surgery, the risk of having a stroke dropped by 7.1% in people who underwent delayed surgery, compared to about a 19% decline in those treated without delay.
The reduction in stroke prevention makes sense, according to Barnett, since the benefits of any medical treatment are always greatest in the severest cases. This does not mean that surgery is not worth it for some people who delay treatment several years after symptoms develop, he noted. But they should be informed that they may not get the “clarion clear” benefits that early surgery brings, he said.
, 百拇医药
The trial also gave researchers a chance to observe the changes that occur in the arteries of people who are treated with drugs alone, Barnett explained.
While blocked arteries worsened about 10% of the time, they improved in about 10% of patients, he said. And levels of blockage stayed about the same in more than half of the medically treated patients, Barnett added.
The findings suggest that for people with partially blocked carotid arteries who do not continue to have symptoms, it is not necessary to conduct a scan of the artery frequently, according to Barnett. “Every couple of years would appear to be reasonable to check things out.” he said., 百拇医药(Merritt McKinney)
A study called the North American Symptomatic Carotid Endarterectomy Trial (NASCET) that began in 1987 was designed to see whether endarterectomy could prevent stroke in people with a partially to nearly completely blocked carotid artery.
, http://www.100md.com
While everyone enrolled in the study received medical treatment for stroke risk factors like high blood pressure, high blood sugar and high cholesterol levels, half of the participants also underwent the artery-clearing surgery, according to the study's lead investigator, Dr. Henry J.M. Barnett, of the John P. Robarts Research Institute in Ontario, Canada.
By 1991, it became clear that surgery prevented strokes in people with the most severely blocked arteries--70% to 99% blocked--who had symptoms like face numbness, difficulty speaking and dizziness, Barnett told Reuters Health in an interview. The risk of stroke was about 17% lower in patients treated with surgery, according to Barnett.
, http://www.100md.com
“For severe patients, the study was over.” he said. Since withholding potentially lifesaving treatment would be unethical, all participants in the non-surgery group were given the opportunity to have the surgery.
Barnett said that about half of the group had endarterectomy right away, while others either chose not to have surgery or were so unhealthy that the risks of surgery would have outweighed its potential benefits.
In the September issue of Stroke: Journal of the American Heart Association, Barnett and his colleagues provide an update on the long-term effects of endarterectomy, both in patients who underwent the surgery at the start of the study, as well as those who had surgery in 1991 or later.
, http://www.100md.com
“Endarterectomy proved durable in the long term and reduced the risk of stroke sufficiently so that only five patients need to be treated to prevent one stroke in three years.”the researchers write.
“This is a procedure that lasts.” according to Barnett. “It's not just something that will benefit you for a few months.”
People first treated with drugs alone who later underwent surgery benefited, although the risk of stroke was not reduced as much as in those who had endarterectomy at the start of the study, the study authors explain.
, 百拇医药
Three years after surgery, the risk of having a stroke dropped by 7.1% in people who underwent delayed surgery, compared to about a 19% decline in those treated without delay.
The reduction in stroke prevention makes sense, according to Barnett, since the benefits of any medical treatment are always greatest in the severest cases. This does not mean that surgery is not worth it for some people who delay treatment several years after symptoms develop, he noted. But they should be informed that they may not get the “clarion clear” benefits that early surgery brings, he said.
, 百拇医药
The trial also gave researchers a chance to observe the changes that occur in the arteries of people who are treated with drugs alone, Barnett explained.
While blocked arteries worsened about 10% of the time, they improved in about 10% of patients, he said. And levels of blockage stayed about the same in more than half of the medically treated patients, Barnett added.
The findings suggest that for people with partially blocked carotid arteries who do not continue to have symptoms, it is not necessary to conduct a scan of the artery frequently, according to Barnett. “Every couple of years would appear to be reasonable to check things out.” he said., 百拇医药(Merritt McKinney)