Institute for Diagnostic Radiology and Neuroradiology, Ernst-Moritz-Arndt-University Greifswald, Germany.
J Neurosurg. 2011 Apr;114(4):978-83. doi: 10.3171/2010.6.JNS10117. Epub 2010 Jul 9.
Extracranial-intracranial (EC-IC) bypass surgery remains an important treatment alternative for patients with occlusive cerebrovascular disease. The aim of the present study was to use perfusion CT and CT angiography (CTA) to evaluate cerebral hemodynamics and bypass patency in patients with occlusive cerebrovascular disease before and after EC-IC bypass surgery.
Ten patients underwent perfusion CT and CTA before and after bypass surgery. Preoperative and postoperative digital subtraction angiography served as the diagnostic gold standard. An artery bypass was established from the superficial temporal artery to a cortical branch of the middle cerebral artery. Perfusion CT scanning was performed at the level of the basal ganglia. Color-coded perfusion maps of cerebral blood volume, cerebral blood flow, and time to peak were calculated.
Preoperative perfusion CT showed significant prolonged time to peak and reduced cerebral blood flow of the affected hemisphere. Postoperative neurological deterioration did not develop in any patient. Computed tomography angiography provided adequate evaluation of the anastomoses as well as the course and caliber of the bypass and confirmed bypass patency in all patients. Postoperative perfusion CT showed improved cerebral hemodynamics with a return to nearly normal perfusion parameters.
Computed tomography angiography is a noninvasive and reliable tool for evaluating patients with EC-IC bypass. Perfusion CT allows monitoring of hemodynamic changes after bypass surgery. The combination of both modalities enables noninvasive anatomical and functional analysis of superficial temporal artery-middle cerebral artery anastomoses using a single CT protocol. Hemodynamic evaluation of patients with occlusive cerebrovascular disease before and after surgery may improve the prediction of outcome and may help identify patients in whom a bypass procedure can be performed.
颅外-颅内（EC-IC）旁路手术仍然是治疗闭塞性脑血管病患者的重要治疗选择。本研究旨在使用灌注 CT 和 CT 血管造影（CTA）评估闭塞性脑血管病患者 EC-IC 旁路手术后的脑血流动力学和旁路通畅情况。
10 例患者在旁路手术后进行灌注 CT 和 CTA 检查。术前和术后数字减影血管造影作为诊断金标准。建立了从颞浅动脉到大脑中动脉皮质分支的动脉旁路。在基底节水平进行灌注 CT 扫描。计算脑血容量、脑血流量和达峰时间的彩色编码灌注图。
术前灌注 CT 显示受累半球的达峰时间明显延长，脑血流量减少。术后无任何患者出现神经功能恶化。CTA 充分评估了吻合口以及旁路的走行和口径，并在所有患者中证实了旁路通畅。术后灌注 CT 显示脑血流动力学改善，灌注参数几乎恢复正常。
CTA 是评估 EC-IC 旁路患者的一种非侵入性且可靠的工具。灌注 CT 可监测旁路手术后的血流动力学变化。这两种方法的结合可以使用单一 CT 方案对颞浅动脉-大脑中动脉吻合进行无创解剖和功能分析。手术前后闭塞性脑血管病患者的血流动力学评估可能会提高对预后的预测，并有助于识别可以进行旁路手术的患者。
