Hemodynamic effects of enhanced external counterpulsation on cerebral arteries: a multiscale study
Hemodynamic effects of enhanced external counterpulsation on cerebral arteries: a multiscale study
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增强体外反搏对脑动脉血流动力学的影响：一项多尺度研究
DOI：
10.1186/s12938-019-0710-x
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发表时间：
2019-08-28
影响因子：
3.9
通讯作者：
Liu, Youjun
中科院分区：
文献类型：
--
作者：
Li, Bao;Wang, Wenxin;Liu, Youjun
研究背景增强型体外反搏（EECP）是治疗缺血性脑卒中的有效方法，而血流动力学是影响EECP疗效的主要因素。不同的反搏模式有可能导致不同的急性和长期血流动力学变化，从而产生不同的治疗效果。然而，各种问题，适当的反搏模式，以优化血流动力学效果仍然没有回答在临床治疗methodsA零维/三维（0 D/3D）几何多尺度模型的脑动脉建立，以获得急性血流动力学指标，包括平均动脉压（MAP）和脑血流量（CBF），以及局部血流动力学细节的脑动脉，其包括壁面剪切应力（WSS）和振荡剪切指数（OSI）。通过对0 D模型中的小腿、大腿和小腿模块施加压力来实现反搏。应用不同的反搏模式，包括各种压力振幅和加压持续时间，以研究影响急性和长期治疗效果的血流动力学反应。结果EECP治疗过程中，压力幅值和加压持续时间的变化对血流动力学效应有不同程度的影响。当对小腿、大腿和臀部施加相同或不同的压力幅度时，血流动力学存在微小差异。当对身体三个部位施加增加的压力幅度时，MAP和CBF略有改善。当压力振幅超过200 mmHg时，血流动力学指标几乎没有变化，证明与临床数据一致。然而，随着加压持续时间的增加，血流动力学指标显著改善。在加压持续时间为0.5、0.6和0.7 s时，反搏期间MAP的增加百分比分别为1.5%、23.5%和39.0%，CBF的增加百分比分别为1.2%、23.4%和41.6%，时间平均WSS的增加百分比分别为0.2%、43.5%和85.0%。施加到这三个部分的压力幅度可以保持相同。通过过度增加200 mmHg以上的压力幅度，患者可能不会从EECP治疗中获得更多益处。然而，在临床手术期间，在心动周期期间，加压持续时间可增加至0.7 s，以优化血流动力学，从而获得可能的上级治疗结局。
BackgroundEnhanced external counterpulsation (EECP) is an effective method for treating patients with cerebral ischemic stroke, while hemodynamics is the major contributing factor in the treatment of EECP. Different counterpulsation modes have the potential to lead to different acute and long-term hemodynamic changes, resulting in different treatment effects. However, various questions about appropriate counterpulsation modes for optimizing hemodynamic effects remain unanswered in clinical treatment.MethodsA zero-dimensional/three-dimensional (0D/3D) geometric multiscale model of the cerebral artery was established to obtain acute hemodynamic indicators, including mean arterial pressure (MAP) and cerebral blood flow (CBF), as well as localized hemodynamic details for the cerebral artery, which includes wall shear stress (WSS) and oscillatory shear index (OSI). Counterpulsation was achieved by applying pressure on calf, thigh and buttock modules in the 0D model. Different counterpulsation modes including various pressure amplitudes and pressurization durations were applied to investigate hemodynamic responses, which impact acute and long-term treatment effects. Both vascular collapse and cerebral autoregulation were considered during counterpulsation.ResultsVariations of pressure amplitude and pressurization duration have different impacts on hemodynamic effects during EECP treatment. There were small differences in the hemodynamics when similar or different pressure amplitudes were applied to calves, thighs and buttocks. When increasing pressure amplitude was applied to the three body parts, MAP and CBF improved slightly. When pressure amplitude exceeded 200 mmHg, hemodynamic indicators almost never changed, demonstrating consistency with clinical data. However, hemodynamic indicators improved significantly with increasing pressurization duration. For pressurization durations of 0.5, 0.6 and 0.7 s, percentage increases for MAP during counterpulsation were 1.5%, 23.5% and 39.0%, for CBF were 1.2%, 23.4% and 41.6% and for time-averaged WSS were 0.2%, 43.5% and 85.0%, respectively.ConclusionsWhen EECP was applied to patients with cerebral ischemic stroke, pressure amplitude applied to the three parts may remain the same. Patients may not gain much more benefit from EECP treatment by excessively increasing pressure amplitude above 200 mmHg. However, during clinical procedures, pressurization duration could be increased to 0.7 s during the cardiac circle to optimize the hemodynamics for possible superior treatment outcomes.