北美颈内动脉狭窄手术治疗与药物治疗协作研究组：无症状颈动脉狭窄：手术与阿司匹林对照
北美颈内动脉狭窄手术治疗与药物治疗协作研究组 (Carotid Artery Stenosis with Asymptomatic Narrowing: Operation Versus Aspirin， CASANOVA) ：
背景：no randomized study has been completed to investigate whether surgical removal of an asymptomatic stenosis of the internal carotid artery (ICA) can prevent the occurrence of stroke。Because of the lack of reliable information, it was very difficult for the surgeons and neurologists in this study to agree on a study design.
目标：we began a multicenter randomized stratified study to compare the efficacy of operation plus medical treatment with medical
treatment alone in patients with asymptomatic stenosis of the ICA for the prevention of stroke and stroke-related death.
|
终点事件 |
Group A（N=206） |
Group B（N=204） |
|
minor stroke (neurologic deficit for longer than 24 hours, less than 4 weeks),
|
|
|
|
strokes (neurologic deficit exceeding 4 weeks） |
|
|
|
death due to surgery or stroke |
|
|
在 70 年代研究结果认为，内科治疗 TIA 发生缺血性卒中的危险性为每年 3.5% 。缺血性卒中和死亡的全部危险性为 7.1% 。血管内膜切除术组的缺血性卒中发病率为 1.1% ， 1 年死亡和缺血性卒中全部发病率为 5.4% ，手术后 5 年脑卒中危险性减少男性为 66% ，女性为 17% ，全部男女卒中危险性减少 53 ％。
对于无症状颈动脉狭窄如围手术期死亡率降到 3.0% 以下， 5 年脑卒中的危险性降低率也可有明显统计学意义。以上表明手术治疗颈动脉狭窄优于药物治疗。目前进行颈动脉内膜切除术的依据为：有 TIA 病史患者 4 年内约有 35 ％病人发展为完全性脑梗塞， 10-30% 脑梗塞患者均有 TIA 病史。
| 
