Moyamoya disease (MMD) is characterized by narrowing of the distal internal carotid artery and the circle of Willis (CoW) and leads to recurring ischemic and hemorrhagic stroke. A retrospective review of data from 50 pediatric MMD patients revealed that among the 24 who had a unilateral stroke and were surgically treated, 11 (45.8%) had a subsequent, contralateral stroke. There is no reliable way to predict these events. After a pilot study in Acta^−/− mice that have features of MMD, we hypothesized that local hemodynamics are predictive of contralateral strokes and sought to develop a patient-specific analysis framework to noninvasively assess this stroke risk. A pediatric MMD patient with an occlusion in the right middle cerebral artery and a right-sided stroke, who was surgically treated and then had a contralateral stroke, was selected for analysis. By using an unsteady Navier–Stokes solver within an isogeometric analysis framework, blood flow was simulated in the CoW model reconstructed from the patient’s postoperative imaging data, and the results were compared with those from an age- and sex-matched control subject. A wall shear rate (WSR) > 60,000 s⁻¹ (about 12 × higher than the coagulation threshold of 5000 s⁻¹ and 9 × higher than control) was measured in the terminal left supraclinoid artery; its location coincided with that of the subsequent postsurgical left-sided stroke. A parametric study of disease progression revealed a strong correlation between the degree of vascular morphology altered by MMD and local hemodynamic environment. The results suggest that an occlusion in the CoW could lead to excessive contralateral WSRs, resulting in thromboembolic ischemic events, and that WSR could be a predictor of future stroke.

烟雾病 (MMD) 的特征是远端颈内动脉和威利斯环 (CoW) 变窄，并导致复发性缺血性和出血性中风。对 50 名儿科 MMD 患者的数据进行回顾性审查显示，在 24 名单侧中风并接受手术治疗的患者中，11 名 (45.8%) 随后出现对侧中风。没有可靠的方法来预测这些事件。在对具有 MMD 特征的Acta ^−/−小鼠进行初步研究后，我们假设局部血流动力学可以预测对侧中风，并寻求开发针对患者的分析框架来无创评估这种中风风险。选择一名患有右侧大脑中动脉闭塞和右侧中风的儿科 MMD 患者进行分析，该患者接受手术治疗后出现对侧中风。通过在等几何分析框架内使用非稳态纳维-斯托克斯求解器，在根据患者术后成像数据重建的 CoW 模型中模拟血流，并将结果与​​年龄和性别匹配的对照受试者的结果进行比较。在左床突上动脉末端测得壁剪切率 (WSR) > 60,000 s ^-1 （比 5000 s ^-1的凝血阈值高约 12 倍，比对照高 9 倍）；它的位置与随后术后左侧中风的位置一致。疾病进展的参数研究揭示了 MMD 改变的血管形态程度与局部血流动力学环境之间存在很强的相关性。 结果表明，CoW 的闭塞可能导致对侧 WSR 过多，从而导致血栓栓塞性缺血事件，并且 WSR 可能是未来中风的预测因子。