Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
Eur J Vasc Endovasc Surg. 2013 Dec;46(6):631-7. doi: 10.1016/j.ejvs.2013.09.007. Epub 2013 Sep 12.
The occurrence of cerebral ischemia during carotid endarterectomy (CEA) can be prevented by (selective) placement of an intraluminal shunt during cross-clamping. We set out to develop a rule to predict the likelihood for shunting during CEA based on preoperative assessment of collateral cerebral circulation and patient characteristics.
Patients who underwent CEA between 2004 and 2010 were included. Patients without preoperative magnetic resonance (MRA) or computed tomography angiography (CTA) were excluded. The primary endpoint was intraluminal shunt placement based on electroencephalography changes. Age, sex, cardiovascular risk factors peripheral artery disease, symptomatic status, degree of ipsilateral and contralateral carotid, status of the vertebral arteries, and morphology of the CoW were studied as potential predictors for shunt use. A prediction model was derived from a multivariable regression model using discrimination, calibration, and bootstrapping approaches and transformed into a clinical prediction model.
A total of 431 patients were included, of which 65 patients (15%) received an intraluminal shunt. In the MRA group (n = 285) factors related to shunt use in multivariate analysis were ipsilateral carotid stenosis 90-99% (odds ratio [OR] 0.15, 95% CI 0.04-0.53), contralateral carotid occlusion (OR 4.29, 95% CI 1.68-10.95) and any not-visible anterior (OR 4.96, 95% CI 1.95-12.58) or ipsilateral posterior segment of the CoW (OR 5.08, 95% CI 2.10-12.32). In the CT group none of the factors were independently related to shunt use; therefore, only predictors describing morphology of CoW derived from MRA findings were included in our model. The c-statistic of this model was 0.79 (95% CI 0.72-0.86). Among patients with an estimated chance of needing a shunt of under 10% (49% of the population), the likelihood of shunting was 5%. In those in whom this chance was estimated higher than 30% (13% of the population) the likelihood was 51%.
Among patients scheduled for CEA, assessment of cerebral arteries and of the configuration of the CoW based on MRA-derived images can help to identify patients with low and high likelihood of the need of shunt use during surgery.
在颈动脉内膜切除术（CEA）过程中，可以通过在夹闭时放置管内分流器来预防脑缺血的发生。我们旨在制定一种规则，根据术前评估侧支循环和患者特征来预测 CEA 期间分流的可能性。
纳入 2004 年至 2010 年间接受 CEA 的患者。排除术前无磁共振（MRA）或计算机断层血管造影（CTA）检查的患者。主要终点是根据脑电图变化放置管内分流器。研究年龄、性别、心血管危险因素、外周动脉疾病、症状状态、同侧和对侧颈动脉的程度、椎动脉状态以及 Cow 形态等因素，作为分流器使用的潜在预测因素。使用判别、校准和自举方法从多变量回归模型中得出预测模型，并将其转化为临床预测模型。
共纳入 431 例患者，其中 65 例（15%）接受了管内分流器。在 MRA 组（n=285），多变量分析中与分流器使用相关的因素包括同侧颈动脉狭窄 90-99%（比值比 [OR] 0.15，95%置信区间 [CI] 0.04-0.53）、对侧颈动脉闭塞（OR 4.29，95% CI 1.68-10.95）和任何不可见的前（OR 4.96，95% CI 1.95-12.58）或同侧后段 Cow（OR 5.08，95% CI 2.10-12.32）。在 CT 组中，没有一个因素与分流器使用独立相关；因此，仅包括从 MRA 结果中描述 Cow 形态的预测因素纳入我们的模型。该模型的 C 统计量为 0.79（95%CI 0.72-0.86）。在估计需要分流器的机会低于 10%（人群的 49%）的患者中，分流器的使用可能性为 5%。在估计机会高于 30%（人群的 13%）的患者中，这种可能性为 51%。
在计划接受 CEA 的患者中，基于 MRA 衍生图像评估脑动脉和 Cow 的形态，可以帮助识别低和高需要使用分流器的可能性的患者。
