Shook D R, Beaudet L M, Doppman J L
Biomedical Engineering and Instrumentation Branch, National Institutes of Health, Bethesda, Maryland.
J Neurosurg. 1987 Nov;67(5):726-31. doi: 10.3171/jns.1987.67.5.0726.
Drug streaming has been implicated in the development of focal necrotic lesions in perfused tissues following intracarotid chemotherapy of brain tumors at low infusion rates. The narrow infusate path characteristic of streaming within laminar blood flow is not observed at high infusion rates such as are typical in contrast injection for angiography. By periodically pulsing the infusate at a high rate, the mechanisms of rapid mixing can be exploited while retaining the practicality of low average infusion rates. This in vitro study demonstrates the effects of the pulse-controlling parameters and the catheter characteristics and placement on mixing effectiveness. An internal carotid artery model including eight cerebral branches was infused with dye through various indwelling catheters, and individual branch effluents were collected and analyzed spectrophotometrically for dye concentration. While catheter placement dominates the factors that control infusate distribution, judicious selection of the pulse parameters can alleviate that dependence. A primary advantage is gained by phasing the pulse to occur during that period of the cardiac cycle when the blood flow is lowest at the injection site. The data clearly showed that diastole-phased pulsed infusions are highly effective in producing a uniform infusate distribution at low average infusion rates.
在脑肿瘤颈动脉内化疗时，低输注速率下药物流注与灌注组织中局灶性坏死病变的发展有关。在层流血液中流注的特征性狭窄注入液路径，在高输注速率下（如血管造影对比剂注射时的典型速率）并未观察到。通过以高频率周期性地脉冲注入液，可以利用快速混合的机制，同时保持低平均输注速率的实用性。这项体外研究展示了脉冲控制参数、导管特性及放置对混合效果的影响。通过各种留置导管向包含八个脑部分支的颈内动脉模型注入染料，收集各个分支流出液，并通过分光光度法分析染料浓度。虽然导管放置主导着控制注入液分布的因素，但明智地选择脉冲参数可以减轻这种依赖性。通过使脉冲在心动周期中注射部位血流最低的时期发生，可获得一个主要优势。数据清楚地表明，舒张期相位脉冲输注在低平均输注速率下能非常有效地产生均匀的注入液分布。
