Nagasawa S, Ohta T, Kikuchi H, Nagayasu S
Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan.
Acta Neurochir (Wien). 1995;132(1-3):120-6. doi: 10.1007/BF01404858.
A hydraulic vascular model of the vertebrobasilar artery with an autoregulatory mechanism was constructed. The haemodynamic effect of superficial temporal artery (STA)-posterior cerebral artery (PCA) bypass was investigated in cases of bilateral vertebral artery (VA) occlusion and basilar artery (BA) occlusion. Assuming therapeutic BA occlusion for basilar bifurcation aneurysms, the flow volume through the P1 segment of the PCA was determined in relation to diameters of the posterior communicating artery (PCom). The bypass increases both flow volume and intraluminal pressure in the presence range below 60 mm Hg, while it increases only pressure in the autoregulatory range above 60 mm Hg. Its haemodynamic effect is more marked in BA occlusion than in VA occlusion. The averaged values of the increase in flow volume are 29.0 +/- 4.3% (mean +/- SD) and 16.5 + 1.0%, respectively. The total flow volume increase of the vertebrobasilar system is usually lower than the flow volume measured at the bypassed STA. The difference between the two is equal to the simultaneous decrease in flow volume through the PComs. Flow volume through the P1 segment can be expressed as a function of the PComs diameter ratio squared. A hydraulic simulation study will be useful for speculating on the haemodynamic effects of these operative procedures.
构建了具有自动调节机制的椎基底动脉液压血管模型。在双侧椎动脉（VA）闭塞和基底动脉（BA）闭塞的情况下，研究了颞浅动脉（STA）-大脑后动脉（PCA）搭桥术的血流动力学效应。假设对基底动脉分叉处动脉瘤进行治疗性BA闭塞，根据后交通动脉（PCom）的直径确定通过PCA的P1段的血流量。在血压低于60 mmHg的范围内，搭桥术可增加血流量和管腔内压力，而在血压高于60 mmHg的自动调节范围内，搭桥术仅增加压力。其血流动力学效应在BA闭塞时比在VA闭塞时更明显。血流量增加的平均值分别为29.0 +/- 4.3%（均值 +/- 标准差）和16.5 + 1.0%。椎基底动脉系统的总血流量增加通常低于在搭桥的STA处测得的血流量。两者之间的差异等于通过PComs的血流量同时减少。通过P1段的血流量可以表示为PComs直径比平方的函数。液压模拟研究将有助于推测这些手术操作的血流动力学效应。
