Hendrikse J, Hartkamp M J, Hillen B, Mali W P, van der Grond J
Departments of Radiology, University Medical Center Utrecht, The Netherlands.
Stroke. 2001 Dec 1;32(12):2768-73. doi: 10.1161/hs1201.099892.
The circle of Willis is regarded as the major source of collateral flow in patients with severe carotid artery disease. The purpose of the present study was to assess whether the presence of border zone infarcts is related to the collateral ability of the circle of Willis in symptomatic (transient ischemic attack, minor stroke) and asymptomatic patients with unilateral occlusion of the internal carotid artery (ICA).
Fifty-one patients (35 symptomatic, 16 asymptomatic) and 53 control subjects were investigated. Patients had unilateral occlusion of the ICA and contralateral ICA stenosis between 0% and 69%. The directions of flow, on the side of the ICA occlusion, and the size of the component vessels in the circle of Willis were investigated with MR angiography.
On average, 92% of the patients without border zone infarcts (n=26) had willisian collateral flow compared with 60% of patients with border zone infarcts (n=25; P<0.05). This increase in collateral flow was caused by the high prevalence of collateral flow via the posterior communicating artery in patients without border zone infarcts (50% versus 12%; P<0.05). No statistically significant relation was found between the pattern of collateral flow via the circle of Willis and the presence of clinical symptoms. Nevertheless, asymptomatic patients with ICA occlusion demonstrated an increased diameter of the anterior communicating artery (P<0.05).
In patients with unilateral ICA occlusion, the presence of collateral flow via the posterior communicating artery in the circle of Willis is associated with a low prevalence of border zone infarcts. Asymptomatic patients with an ICA occlusion do not have an increased collateral function of the circle of Willis.
Willis 环被认为是重度颈动脉疾病患者侧支循环的主要来源。本研究的目的是评估在有症状（短暂性脑缺血发作、轻度卒中）和无症状的单侧颈内动脉（ICA）闭塞患者中，边缘带梗死的存在是否与 Willis 环的侧支循环能力相关。
对 51 例患者（35 例有症状，16 例无症状）和 53 例对照者进行了研究。患者存在单侧 ICA 闭塞且对侧 ICA 狭窄在 0%至 69%之间。通过磁共振血管造影研究 ICA 闭塞侧的血流方向以及 Willis 环中各组成血管的大小。
平均而言，无边缘带梗死的患者（n = 26）中有 92%存在 Willis 环侧支循环，而有边缘带梗死的患者（n = 25）中这一比例为 60%（P < 0.05）。侧支循环的增加是由于无边缘带梗死的患者通过后交通动脉形成侧支循环的比例较高（50%对 12%；P < 0.05）。未发现通过 Willis 环的侧支循环模式与临床症状的存在之间存在统计学显著关系。然而，ICA 闭塞的无症状患者前交通动脉直径增大（P < 0.05）。
在单侧 ICA 闭塞的患者中，Willis 环通过后交通动脉形成侧支循环与边缘带梗死的低发生率相关。ICA 闭塞的无症状患者 Willis 环的侧支循环功能并未增强。
