Massaro A R, Young W L, Kader A, Ostapkovich N, Tatemichi T K, Stein B M, Mohr J P
Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
AJNR Am J Neuroradiol. 1994 Jan;15(1):55-61.
To characterize cerebral hemodynamics in patients immediately before microsurgical resection of moderate to large arteriovenous malformations during isoflurane anesthesia.
In angiographically defined arteriovenous malformation feeding and nonfeeding arteries, transcranial Doppler studies were performed in 25 surgeries on 22 patients. The mean blood flow velocity and pulsatility index were recorded in the middle, anterior, and posterior cerebral arteries. Transcranial Doppler velocities were measured at end-tidal carbon dioxide tensions (PetCO2) of about 25 and 35 mm Hg. Carbon dioxide reactivity was calculated as percentage mean blood flow velocity change per mm Hg PetCO2 change.
Patient demographic and clinical data for the arteriovenous malformation group followed the expected strata of a large arteriovenous malformation population. All patients were neurologically stable before surgery. A total of 43 feeding arteries and 55 nonfeeding arteries were studied. Compared with nonfeeders, feeders exhibited higher mean blood flow velocity (68 +/- 5 vs 31 +/- 3 cm/sec, P < 0.0001) and lower pulsatility index (0.64 +/- 0.03 vs 0.88 +/- 0.04, P < 0.001); anterior and middle cerebral artery velocities at normo- and hypocapnia were significantly higher than posterior cerebral arteries for both feeders and nonfeeders (P < 0.001). Carbon dioxide reactivity was 0.2 +/- 0.2%/mm Hg in feeders and 2.1 +/- 0.2%/mm Hg in nonfeeders, with no significant difference between arteries. In four of eight patients with lesions fed by the anterior circulation (middle cerebral artery with or without anterior cerebral artery feeders), posterior cerebral artery nonfeeders exhibited low reactivity. In 2 of 5 patients with ipsilateral posterior cerebral artery feeders, contralateral posterior cerebral artery nonfeeders exhibited impaired reactivity.
Quantitative transcranial Doppler studies are technically feasible in the operating room or interventional suite during anesthesia. Hemodynamic assessment using physiologic challenges of arteriovenous malformation feeders as well as angiographically uninvolved vessels may be useful as criteria in the assessment of malformations and arteriovenous malformation patients may exhibit abnormal vasoreactivity in distant uninvolved perfusion territories, suggesting a deranged neural control mechanism.
对异氟烷麻醉下中大型动静脉畸形患者进行显微手术切除前即刻的脑血流动力学特征进行描述。
在22例患者的25台手术中，对血管造影确定的动静脉畸形供血动脉和非供血动脉进行经颅多普勒研究。记录大脑中动脉、前动脉和后动脉的平均血流速度和搏动指数。在呼气末二氧化碳分压（PetCO2）约为25和35mmHg时测量经颅多普勒速度。二氧化碳反应性计算为每mmHg PetCO2变化时平均血流速度变化的百分比。
动静脉畸形组患者的人口统计学和临床数据符合大型动静脉畸形人群的预期分层。所有患者术前神经功能稳定。共研究了43条供血动脉和55条非供血动脉。与非供血动脉相比，供血动脉表现出更高的平均血流速度（68±5 vs 31±3cm/秒，P<0.0001）和更低的搏动指数（0.64±0.03 vs 0.88±0.04，P<0.001）；对于供血动脉和非供血动脉，正常碳酸血症和低碳酸血症时大脑前动脉和中动脉的速度均显著高于大脑后动脉（P<0.001）。供血动脉的二氧化碳反应性为0.2±0.2%/mmHg，非供血动脉为2.1±0.2%/mmHg，动脉之间无显著差异。在前循环供血的8例患者中的4例（大脑中动脉有或无大脑前动脉供血），大脑后动脉非供血动脉表现出低反应性。在5例同侧大脑后动脉供血的患者中的2例，对侧大脑后动脉非供血动脉表现出反应性受损。
定量经颅多普勒研究在麻醉期间的手术室或介入室中技术上是可行的。利用动静脉畸形供血动脉以及血管造影未累及血管的生理刺激进行血流动力学评估，可能作为评估畸形的标准有用，并且动静脉畸形患者在远处未累及的灌注区域可能表现出异常的血管反应性，提示神经控制机制紊乱。
