评估颈动脉阻断后脑侧支循环代偿能力--经颅多普勒脑血流检测法

目的:探讨在经颅彩色多普勒(TCD)辅助下,行肿瘤合并颈动脉切除术前,颈动脉压迫训练时脑血流动力学改变的临床价值.方法:采用TCD为14例手术患者经颞窗检测,观察在阻断患侧颈动脉后双侧ACA(大脑前动脉),MCA(大脑中动脉)的血流速度变化和Willis环开放情况.结果:通过颈动脉压迫训练,DSA(数字减影脑血管造影)和TCD检测发现9例病人(64.3%,9/14)Willis环代偿能力不良,在接受颈动脉压迫训练2～6周后,TCD检测其开放状态和脑侧枝循环建立良好,患侧ACA、MCA血流速度基本达到阻断前水平,颈动脉压迫训练前、后患侧颈动脉阻断时TCD检测对照ACA t=19.278,P＜0.05;MCA t=22.278,P＜0.05,ACA和MCA训练前后颈动脉阻断时比较差异有显著性,符合颈动脉切除术标准.14例随访1年以上未见肿瘤复发,无1例手术死亡或脑血管并发症.结论:TCD是-种无创伤,重复性好,安全可靠,易被接受的脑血流监测评估手段,对肿瘤合并颈动脉切除术尤为重要.

Transcranial Doppler Evaluation of Cerebral Collateral Circulation as An Approach for--Cerebral Blood Flow Monitoring after Carotid Obstruction

Objective:To investigate the clinical value of transcranial doppler test(TCD) in cerebral hemodynamic monitoring for selective patients who were having carotid pressure training before tumor-carotid segment block resection.Methods: The blood velocity variations of left and right anterior cerebral arteries(ACA) and the middle cerebral artery(MCA) in the 14 patients,after their carotids were obstructed,were checked with TCD through temporal windows.Results: Nine of the 14 patients(64.3%),who were found to have insufficient Willis ring compensation by TCD and digital subtraction angiography(DSA),experienced re-opened rings well-constructed cerebral collateral circulations after receiving carotid pressure training for 2 to 6 weeks,monitored by TCD.All blood flow velocities of affected ACA and MCA had resumed unobstructed level with significant differences before and after training(ACA t=19.278,P<0.05;MCA t=22.278,P<0.05),which fulfilled the standards of carotid resection.Follow-up of these 14 patients over 1 year revealed that neither death from operation nor cerebral vascular complications occurred in patients with effective carotid training confirmed by TCD and DSA tests.Conclusions: As a non-invasive and reproducible approach to monitor cerebral blood velocity,TCD is safe and reliable,easily accepted by patients,and especially important for tumor-carotid segment block resection.