Young W L, Prohovnik I, Ornstein E, Ostapkovich N, Sisti M B, Solomon R A, Stein B M
Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, New York.
Neurosurgery. 1990 Aug;27(2):257-66; discussion 266-7. doi: 10.1097/00006123-199008000-00015.
To investigate the cerebral hemodynamic changes associated with obliteration of arteriovenous malformations (AVMs), we studied 26 patients undergoing total microsurgical AVM resection during isoflurane and N2/O2 anesthesia. Detectors were placed 5 to 6 cm from the margin of the lesion and in a homologous contralateral position. Cerebral blood flow (CBF) was measured using the intravenous xenon-133 technique before and after AVM resection, during both hypocapnia and normocapnia at each stage. Intraoperative changes in CBF were related to a risk score system based on the patient's history and preoperative angiograms. Seven otherwise healthy patients undergoing spinal surgery were studied to control for anesthetic effects. Patient demographic and clinical data for the AVM group conformed to the expected strata of a large AVM population. The CBF increased after excision (22 +/- 1 ml/100 g/min before excision to 30 +/- 2 ml/100 g/min after excision; mean +/- SE, n = 25, P less than 0.002) without a hemispheric difference. CO2 reactivity increased slightly after excision (4.2 +/- 0.3% change/mm Hg before excision to 4.7 +/- 0.3% change/mm Hg after excision; n = 14, P less than 0.02). The baseline CBF and CO2 reactivity were not different from the control group. There was a weak correlation between the risk score and the percentage of change in the ipsilateral CBF, with a trend for the patients with the lowest risk to have the lowest CBF changes after resection. There was no relationship between CO2 reactivity and risk grade. None of the patients awoke from anesthesia with unexpected neurological deficits. The highest CBF increases were associated with postoperative brain swelling in one patient and fatal intracerebral hemorrhage in another. Both patients had normal CO2 reactivity before excision. One patient suffered postoperative intracerebral hemorrhage, attributable to technical problems, and had no increase in CBF. We conclude that, with an acute increase in the arteriovenous pressure gradient (and cerebral perfusion pressure) that results from shunt obliteration, there is an immediate global effect of AVM resection to increase CBF. Cerebrovascular reactivity to CO2 remains intact both before and after excision.
为研究与动静脉畸形（AVM）闭塞相关的脑血流动力学变化，我们对26例在异氟烷和N2/O2麻醉下接受AVM全显微切除术的患者进行了研究。探测器放置在距病变边缘5至6厘米处且位于对侧同源位置。在AVM切除术前和术后，在每个阶段的低碳酸血症和正常碳酸血症期间，使用静脉注射氙-133技术测量脑血流量（CBF）。术中CBF的变化与基于患者病史和术前血管造影的风险评分系统相关。对7例接受脊柱手术的其他方面健康的患者进行了研究以控制麻醉效果。AVM组的患者人口统计学和临床数据符合大型AVM人群的预期分层。切除后CBF增加（切除前22±1 ml/100 g/min至切除后30±2 ml/100 g/min；平均值±标准误，n = 25，P＜0.002），且无半球差异。切除后二氧化碳反应性略有增加（切除前4.2±0.3%变化/mm Hg至切除后4.7±0.3%变化/mm Hg；n = 14，P＜0.02）。基线CBF和二氧化碳反应性与对照组无差异。风险评分与同侧CBF变化百分比之间存在弱相关性，风险最低的患者在切除后CBF变化最低的趋势。二氧化碳反应性与风险等级之间无关系。没有患者在麻醉苏醒后出现意外的神经功能缺损。CBF增加最高的情况与一名患者术后脑肿胀和另一名患者致命性脑出血相关。两名患者在切除前二氧化碳反应性均正常。一名患者因技术问题发生术后脑出血，且CBF未增加。我们得出结论，由于分流闭塞导致动静脉压力梯度（和脑灌注压）急性增加，AVM切除会立即产生增加CBF的整体效应。切除前后脑血管对二氧化碳的反应性均保持完整。
