Crawley F, Clifton A, Brown M M
Division of Clinical Neuroscience, St. George's Hospital Medical School, Department of Neuroradiology, Atkinson Morley's Hospital, Institute of Neurology, London, UK.
Stroke. 1999 Feb;30(2):312-6. doi: 10.1161/01.str.30.2.312.
The purpose of this study was to establish whether individuals with a family history of >/=2 first-degree relatives with intracranial aneurysm should be offered screening for aneurysm.
We derived 3 theoretical models and calculated the outcomes of screening with magnetic resonance angiography (MRA) followed by digital subtraction angiography (DSA) if MRA was positive (model 1), screening with DSA alone (model 2), and not screening (model 3). Screening was repeated at intervals of 10 years, and aneurysms detected were treated surgically. We assumed a prevalence of aneurysm of 9.8% (95% CI, 8.9% to 10.6%) in the population screened, an annual rupture rate of asymptomatic aneurysm of 0.8% (95% CI, 0.4% to 1.5%), and a 75% chance of poor outcome from rupture. We assumed the sensitivity and specificity of MRA were each 90% and the risk of DSA was 0.1%. The risk of surgery was taken as 5.1%.
Screening 1000 individuals on 3 occasions with MRA and DSA or with DSA alone followed by surgery resulted in poor outcome in 14 and 18 individuals, respectively, over 30 years. Without screening, poor outcome occurred in 15 individuals over the same period of time.
Screening is not an effective way of reducing morbidity and mortality from ruptured intracranial aneurysm in individuals with a history of >/=2 affected first-degree relatives with ruptured intracranial aneurysm unless the expected incidence of asymptomatic aneurysm is considerably >10%.
本研究的目的是确定对于有≥2名一级亲属患有颅内动脉瘤的个体，是否应进行动脉瘤筛查。
我们推导了3种理论模型，并计算了以下3种情况的结果：先用磁共振血管造影（MRA）进行筛查，若MRA呈阳性则接着进行数字减影血管造影（DSA）（模型1）；仅用DSA进行筛查（模型2）；不进行筛查（模型3）。筛查每隔10年重复进行一次，检测出的动脉瘤进行手术治疗。我们假设在接受筛查的人群中动脉瘤的患病率为9.8%（95%可信区间，8.9%至10.6%），无症状动脉瘤的年破裂率为0.8%（95%可信区间，0.4%至1.5%），破裂导致不良后果的概率为75%。我们假设MRA的敏感性和特异性均为90%，DSA的风险为0.1%。手术风险为5.1%。
在30年期间，对1000名个体进行3次MRA和DSA联合筛查或仅进行DSA筛查然后手术，分别导致14例和18例出现不良后果。不进行筛查的情况下，同期有15例出现不良后果。
对于有≥2名患颅内动脉瘤的一级亲属的个体，筛查并非降低颅内动脉瘤破裂所致发病率和死亡率的有效方法，除非无症状动脉瘤的预期发病率显著>10%。
