经颅多普勒检测法评估颈动脉阻断后脑侧支循环代偿能力的临床意义

目的:探讨在经颅彩色多普勒(TCD)引导下,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,MCA和PCD的血流速度变化和Willis环开放情况。结果:通过DSA,MATAS和TCD检测发现9例患者(9/14,64.3%)Willis环代偿能力不良,在接受颈动脉压迫训练4~6周后,TCD检测其开放状态和大脑侧支循环建立良好,患侧ACA、MCA、PCA血流速度接近于阻断前水平,ACA、MCA的平均血流速度首次训练与训练之前比较有显著性差异,其分别为P<0.004和P<0.03,而训练前与训练结束后测值均无显著性差异(P>0.05),提示已符合颈动脉切除术要求。结论:TCD是一种无创伤、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,TCD能否完全取代DSA还需进一步探讨。

Evaluation of the compensatory ability of cerebral collateral circulation after carotid obstruction by TCD

Objective: To promote the clinical value of applying transcranial Doppler test(TCD) to monitor the cerebral hemodynamic changes before tumor-carotid segment block resection, while the patients were having the carotid pressure training, under the guidance of TCD. Methods: Fourteen patients were selected. Before and after carotid artery obstruction. The blood velocity changes of anterior cerebral artery(ACA), middle cerebral artery(MCA) and posterior cerebral artery(PCD) on each side were measured by TCD(through temporal windows). Results: Nine of the 14 cases(64.3%) were found that the compensative capacity of their Willis circle were insufficient through examination of DSA, MATAS and TCD. After receiving the pressure training for 4 to 6 weeks, the cerebral collateral circulations were constructed well via observation of TCD. All blood velocity of the affected side of ACA, MCA and PCA had reached the level before obstruction. After receiving the pressure training for the first time, the velocity of ACA and MCA had significant differences compared with those of receiving training before(P<0.004 and P<0.03), while there was no significant differences between the velocity before and 6 weeks after training(P>0.05). This conform to the criteria of the carotid resection. Conclusions: TCD is a non-traumatic and reproducibility way to monitor cerebral blood velocity, which is safe and reliable and easily accepted by patients, especially important for tumor-carotid segment block resection, but the question whether DSA will be completely replaced by TCD needs further studies.