Evaluation of the cerebral vasodilatory capacity by the acetazolamide test before EC-IC bypass surgery in patients with occlusion of the internal carotid artery.
Evaluation of the cerebral vasodilatory capacity by the acetazolamide test before EC-IC bypass surgery in patients with occlusion of the internal carotid artery.
复制标题
颈内动脉闭塞患者 EC-IC 搭桥手术前乙酰唑胺试验评价脑血管舒张能力。
作者：
S. Vorstrup;B. Brun;N. Lassen
对18例脑血管病患者在颅外-颅内搭桥术前和术后4个月用氙气-133吸入断层扫描测定脑血流量(CBF)。只有在CT扫描显示与临床和血管造影结果相关的区域内脑血流量减少的患者才会接受手术。大多数患者都经历过轻微中风，并有或没有随后的短暂性脑缺血发作。他们在中风后至少6周进行了研究。所有患者都有相关的颈内动脉闭塞。为了在术前确定侧支循环受损并因灌注压降低而导致脑血流量减少的患者，使用乙酰唑胺(Diamox)进行了脑血管扩张负荷试验。在正常受试者中，Diamox已被证明在不改变血流分布的情况下增加断层脑血流。在本系列研究中，有9名患者表现出明显的血流重新分配倾向于非闭塞侧(“阳性”Diamox试验)。在这9名患者中，有两名患者在术前甚至表现出局灶性脑血流量的矛盾下降，即“偷窃”效应。这2例均为分流术后局灶性脑血流改善的唯一患者。其余9例患者均表现为均匀血流反应(Diamox试验为“阴性”)，术后局灶性脑血流无一例增加。术后血流图无变化，证实低流量区不是由于侧支循环血流受限所致。然而，在大多数患者术后观察到局部血管扩张能力的增加。
Cerebral blood flow (CBF) was measured by xenon-133 inhalation tomography in 18 patients with cerebrovascular disease before and 4 months after extracranial-intracranial bypass surgery. Only patients who showed a reduced CBF in areas that were intact on the CT scan and relevant to the clinical and angiographical findings were operated. The majority of the patients had suffered a minor stroke with or without subsequent transient ischemic attacks. They were studied at least 6 weeks following the stroke. All patients had an occlusion of the relevant internal carotid artery. To identify preoperatively the patients with a compromised collateral circulation and hence reduced CBF due to reduced perfusion pressure, a cerebral vasodilatory stress test was performed using acetazolamide (Diamox). In normal subjects, Diamox has been shown to increase tomographic CBF without change of the flow distribution. In the present series 9 patients showed a significant redistribution of flow in favor of the non-occluded side ("positive" Diamox test). Two of these 9 patients showed even a paradoxical decrease in focal CBF preoperatively, i.e., a "steal" effect. These 2 patients were the only patients who improved in focal CBF after shunting. The remaining 9 patients all showed uniform flow responses ("negative" Diamox test), and none of these increased in focal CBF postoperatively. The finding of an unchanged flow map postoperatively confirmed that the low flow areas were not due to restricted flow via collateral pathways. However, an increase in the regional vasodilatory capacity was observed postoperatively in the majority of patients.