Abstract

Differentiating carotid near-occlusion (tight atherosclerotic stenosis causing distal artery size reduction) from conventional stenosis is the first step when grading carotid stenoses with NASCET method. The internal carotid artery (ICA) can be asymmetrically associated with Circle of Willis variations. When such ICA asymmetry coincides with stenosis, it may mimic near-occlusion. We studied ICA anatomical variant prevalence in 4042 consecutive CTA exams from all indications, 53 excluded due to carotid occlusion, 814 with any ≥ 50% steno-occlusive disease intra- or extracranially, 3228 without. Of the 3989 included cases, 568 (14%) had ICA asymmetry, of which 335 (59%) were from associated with Circle of Willis variations. Of 3228 patients without ≥ 50% stenosis or other steno-occlusive disease intra- and extracranially; 257 (8.0%) demonstrated ICA asymmetry associated with Circle of Willis variations, equally common among sexes and age unrelated and most frequently attributed to an ipsilateral A1 hypoplasia/aplasia, less often attributed to large contralateral posterior communicating artery. As ICA asymmetry associated with Circle of Willis variations are common, caution should be exercised diagnosing near-occlusion on asymmetry alone.

中文翻译：

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动脉粥样硬化性ICA狭窄与与Willis变异圈相关的ICA不对称性相吻合可以模仿近闭塞

摘要

在用NASCET方法对颈动脉狭窄进行分级时，将颈动脉近闭（狭窄的动脉粥样硬化狭窄导致远端动脉缩小）与常规狭窄区分开是第一步。颈内动脉（ICA）可能与Willis变异环不对称相关。当这种ICA不对称与狭窄同时发生时，它可能模仿近乎阻塞。我们在所有适应症的4042次连续CTA检查中研究了ICA解剖学变异的患病率，其中53例由于颈动脉闭塞而被排除，814例颅内或颅外有≥50％的狭窄闭塞性疾病，3228例没有。在3989个病例中，有568个（14％）患有ICA不对称，其中335个（59％）来自与Willis变异相关。在3228例颅内和颅外无狭窄≥50％或其他狭窄闭塞性疾病的患者中；257（8。0％）表现出与Willis变异相关的ICA不对称性，在性别和年龄无关的人群中同样普遍，并且最常见归因于同侧A1发育不全/轻瘫，而较少归因于对侧后方沟通大动脉。由于与Willis环变异相关的ICA不对称现象很普遍，因此应谨慎诊断仅因不对称性而发生的近阻塞。