Section of Cardiac Surgery, Yale University School of Medicine, New Haven, CT 06510, USA.
J Neurointerv Surg. 2012 Mar;4(2):130-3. doi: 10.1136/jnis.2010.004432. Epub 2011 Jun 14.
The neuroprotective effects of cooling the spinal cord in a sheep model by a self-contained intrathecal catheter was reported recently by the authors. The present study was designed to determine if cooling catheters in the lateral ventricles of the brain can effectively cool the CSF and thereby reduce brain temperature while maintaining systemic normothermia.
The cooling catheter is a self-contained system that circulates a cold fluid and cools the CSF that circulates in the brain. The CSF in turn cools the surrounding brain by conduction. Burr holes were made in the skull and the catheter was placed into the lateral ventricles using the standard method for placement of ventriculostomy catheters. To monitor the cooling effect, four temperature probes were placed in the brain (left and right hemispheres of the brain in anterior and posterior locations to the ventricles).
Five experiments were successfully completed. The mean brain temperature for all sheep decreased to 34.5°C (mean) during the 3 h cooling period (9.7% reduction from baseline brain temperature of 38.2°C). Cooling fluid was circulated through the catheter at a rate of 50 ml/min. The lowest achieved brain temperature during cooling was 26.7°C. When cooling was stopped, the brain temperature readings equilibrated with the core temperature promptly. Post mortem examination of the brains showed no morphologic changes under gross or histologic examinations.
Localized cooling of the brain to moderate hypothermic levels while maintaining relative systemic normothermia was demonstrated in an animal model with intraventricular cooling catheters.
作者最近报道了一种通过独立的鞘内导管对绵羊模型中的脊髓进行冷却的神经保护作用。本研究旨在确定在大脑侧脑室中放置冷却导管是否可以有效地冷却 CSF，从而降低脑温，同时保持全身正常体温。
冷却导管是一种独立的系统，可循环使用冷液并冷却在大脑中循环的 CSF。CSF 通过传导反过来冷却周围的大脑。颅骨上开颅，并使用放置脑室造口管的标准方法将导管放置在侧脑室中。为了监测冷却效果，在大脑中放置了四个温度探头（脑室前后左右半球）。
成功完成了 5 项实验。在 3 小时的冷却期间，所有绵羊的平均脑温降至 34.5°C（平均）（与 38.2°C 的基础脑温相比降低了 9.7%）。冷却液以 50ml/min 的速度循环通过导管。冷却时达到的最低脑温为 26.7°C。停止冷却后，脑温读数迅速与核心温度平衡。大脑的大体和组织学检查均未见形态学改变。
在动物模型中，通过脑室冷却导管实现了局部大脑冷却至中度低温水平，同时保持相对全身正常体温。
