经猪副半奇静脉逆行灌注低温保护液对脊髓的保护作用

Protective effect of retrograde venous perfusion of cryogenic liquid via accessory hemiazygos vein on spinal cord of swine

目的:观察在降主动脉常温阻断的过程中,经副半奇静脉逆行灌注低温盐水保护脊髓的可行性和效果。方法:①实验于2003-10/2004-05在北京阜外医院实验外科完成。选用12只成年中国小型香猪,随机分成2组:对照组6只和实验组6只。对照组:常温阻断降主动脉和副半奇静脉60min,再灌注90min。实验组:阻断前游离出副半奇静脉,阻断60min,同时经副半奇静脉逆行灌注低温(4℃)9g/L氯化钠溶液,灌注流速为16.65mL/min。②两组术中监测动脉压、肛温的变化。术后即刻取第2腰椎段脊髓行苏木精-伊红染色,观察脊髓神经原细胞的损伤程度,计算活力指数(切片上有活力的神经元细胞总数除以全部的神经元细胞数)。③用独立样本t检验、方差分析和非参数检验完成统计分析。结果:中国小型香猪12只均进入结果分析。①对照组脊髓损伤较重,有神经元细胞数量的减少、萎缩和变性。实验组的脊髓损伤较轻,神经元细胞大致正常。②实验组的神经元细胞活力指数明显高于对照组(0.51±0.06,0.21±0.01,P=0.002)。③降主动脉阻断后两组实验动物的肛温均有下降。对照组和实验组分别在阻断60min和再灌注20min时,肛温降至最低,明显低于阻断前(P<0.01)。两组肛温的下降幅度相近(P>0.05)。另外开放后对照组动物的肛温逐渐回升,至再灌注90min时,肛温与阻断前相近(P>0.05)。而实验组动物的肛温在再灌注后回升不明显,至再灌注90min时,明显低于阻断前(P<0.01)。结论:①经副半奇静脉逆行灌注脊髓在降主动脉的手术中具有可行性和实用性。②经副半奇静脉逆行灌注冷盐水可以减轻因缺血导致的脊髓损伤。

AIM： To observe the feasibility and effect of retrograde venous perfusion of cryogenic saline through accessory hemiazygous vein in protecting the spinal cord during the descending aortic cross clamping. METHODS： ①The experiment was performed in the Department of Experimental Surgery of Fuwai Hospital from October 2003 to May 2004. Twelve adult domestic swine were randomly divided into control group （n=6） and experimental group （n=6）. In the control group, the aorta and the accessory hemiazygous vein were clamped for 60 minutes and then the clamps were removed for 90 minutes; In the experimental group, 9 g/L cold （4℃） saline solution （perfusion rate, 16.65 mL per minute） was infused into the accessory hemiazygous vein during ischemia. ②The changes of arterial pressure and rectal temperature were monitored during the surgery. The second lumbar segment was taken out immediately for haematine-eosin staining to observe the injured severity of spinal neural cells and calculate the viability index （the total number of vital neural cells divided by the number of total neural cells）. ③The independent sample t test, analysis of variance and non-parameter test were used for the statistical analysis. RESUILTS： All the 12 swines were involved in the analysis of results. ① In the control group, the spinal injury was severer, decreased number, atrophy and degeneration of neural cells were observed. In the experimental group, the spinal injury was lighter, and most of the neural cells were normal. ② The viahility index was obviously higher in the experimental group than in the control group （0.51＋0.06, 0.21＋0.01, P=0.002）. ③After descending aortic cross clamping, the rectal temperature was obviously dropped in both groups, and decreased to the lowest at clamped for 60 minutes and reperfusion for 90 minutes in the control group and experimental group respectively, and both were obviously lower than those before clamping （P 〈 0.01）. The decreased range of rectal temperature in the two groups was close （P 〉 0.05）. After patency, the rectal temperature in the control group was increased gradually, and close to that before clamping （P 〉 0.05）. The rectal temperature after reperfusion did not increase obviously, and it was obviously lower at 90 minutes after reperfusion than that before clamping （P 〈 0.01）. CONCLUSION：①Retrograde venous perfusion of spinal cord through accessory hemiazygous vein is feasible and practical in the surgery. ② Retrograde venous perfusion of cold saline through accessory hemiazygous vein can relieve the ischamia-induced spinal injury.