Nakase H, Heimann A, Kempski O
Institute for Neurosurgical Pathophysiology, Johannes Gutenberg University, Mainz, Germany.
Stroke. 1996 Apr;27(4):720-7; discussion 728. doi: 10.1161/01.str.27.4.720.
The pathophysiology of sinus-vein thrombosis (SVT) in patients and experimental animals is still poorly understood. This study was designed to examine and further elucidate the pathophysiological sequence of events, especially the relationship between local and regional blood flow and hemoglobin oxygen saturation (HbSO2) detected at identical locations. The use of both parameters as outcome indicators should be compared.
SVT was induced by ligation of the superior sagittal sinus (SSS) and slow injection of kaolin-cephalin suspension into the SSS in rats. Regional cerebral blood flow (rCBF) was assessed by laser-Doppler flowmetry together with regional HbSO2, which was measured by a microspectrophotometric technique at 48 identical locations for 90 minutes after SVT using a scanning technique. Fluorescence angiography was performed before and 30 and 90 minutes after SVT induction. After 48 hours the animals were killed for histology.
The fluorescence angiographic findings could divide animals into three groups: (1) group A, with a solitary SSS thrombus (n=8); (2) group B, with a thrombosis of SSS and cortical veins (n=10); (3) group C, animals that had undergone sham operation (n=5). Decreases of rCBF and HbSO2 and brain damage were seen in group B but not in group A. The reduction of local HbSO2 preceded the flow decrease after sagittal sinus ligation but before thrombosis. Blood pressure in group A was found to be significantly higher after SVT than in groups B and C.
The brain with acute extension of thrombus from the SSS into cortical veins experiences a critically reduced supply of blood and oxygen. CBF, local HbSO2, and repeated angiography can be helpful monitors for the early detection of critical conditions after SVT. Local HbSO2 has a greater sensitivity to predict outcome than lCBF. Moreover, therapies directed to improve perfusion pressure or reduce vascular resistance may open further therapeutic windows during SVT progression.
患者及实验动物中窦静脉血栓形成（SVT）的病理生理学仍未得到充分理解。本研究旨在检查并进一步阐明事件的病理生理顺序，尤其是在相同位置检测到的局部和区域血流与血红蛋白氧饱和度（HbSO2）之间的关系。应比较将这两个参数用作结局指标的情况。
通过结扎大鼠上矢状窦（SSS）并将高岭土 - 脑磷脂悬浮液缓慢注入SSS来诱导SVT。采用激光多普勒血流仪评估局部脑血流量（rCBF），同时采用微分光光度技术在SVT后90分钟内，于48个相同位置测量区域HbSO2，采用扫描技术进行测量。在SVT诱导前、诱导后30分钟和90分钟进行荧光血管造影。48小时后处死动物进行组织学检查。
荧光血管造影结果可将动物分为三组：（1）A组，有孤立的SSS血栓（n = 8）；（2）B组，有SSS和皮质静脉血栓形成（n = 10）；（3）C组，接受假手术的动物（n = 5）。B组出现rCBF和HbSO2降低以及脑损伤，而A组未出现。矢状窦结扎后但在血栓形成前，局部HbSO2的降低先于血流减少。发现A组在SVT后的血压显著高于B组和C组。
血栓从SSS急性扩展至皮质静脉的脑部，血液和氧气供应严重减少。CBF、局部HbSO2和重复血管造影有助于早期检测SVT后的危急情况。局部HbSO2在预测结局方面比局部脑血流量具有更高的敏感性。此外，旨在提高灌注压或降低血管阻力的治疗可能在SVT进展过程中打开更多治疗窗口。
