犬颈内动脉内冷灌注脑选择性降温对脑保护的实验研究

目的观察颈内动脉内冷灌注犬脑选择性降温对缺血性脑组织的保护作用。方法夹闭左侧颈总动脉、双侧椎动脉、左侧颈外静脉后，自右侧颈内动脉灌入低温灌注液以选择性降低脑温。将颅脑回流的低温稀释静脉血超滤并复温至３８℃后再输入体循环。结果１８只犬中有１４只完成了脑的选择性降温：（５．０±２．０）分钟内降至２８℃，（１０．３±７．２）分钟内降至２０℃，并维持在（１９±１．０）℃达５０分钟，直肠温度保持在（３２．５±２．０）℃以上。１０只长期存活，分别于术后１，２，８，１２周处死，病理检查示犬脑无神经细胞缺血性损伤改变。另４只实验初期因降温后血压显著下降而死亡。结论颈动脉内冷灌注液灌注，可选择性快速、安全地降低脑温，防止脑组织的缺血性损伤，为开展无血手术提供了实验依据。

Selective Cerebral Hypothermia Produced by Intracarotid Perfusion with Cold Perfusate in Dogs

Objective To evaluate the protective effect of selective hypothermia by intracarotid perfusion with cold perfusate on canine ischemic brain. Methods After the left carotid artery, the left jugular vein and both vertebral arteries were clamped simultaneously, and cold solution was immediately perfused into the right internal carotid artery to produce selective cerebral hypothermia. Two needles were distally and proximally inserted respectively into the right jugular vein to extract the hypothermic diluted blood for ultrafiltration and rewarming and then to perfuse the warm blood (38) into the right atrium. Results In 14 (of 18) dogs, the brain temperature decreased to 28 within (5020) minutes and to 20 within (10372) minutes and was maintained at (1910) for 50 minutes. During this interval, the rectal temperature was above (32520) . Ten animals survived in good condition without evidence of neurological deficits until they were killed at 1,2, 8, 12 weeks, respectively. Histological examination of the brains demonstrated no evidence of ischemic lesions. The other four died 1-3 days after operation because of irreversible hypotension. Conclusions Selective cooling of the brain under profound hemodilution has a protective effect on cerebral ischemia and provides a relatively bloodless operative field.