【摘要】 用6毫米的直径的圆形液氮制冷冷冻头(-190℃),对24只家兔的肝左叶进行3分钟的冷冻.实验结果表明,冰球平均直径为21.4毫米.第1分钟的降温速率最快,以后显著减慢.在冰球内部存在着温度梯度.把家兔分成8组,每组3只,冷冻后15分钟、1、3、7、14、28、44和70天.分别处死,取出肝脏作组织切片观察.冷冻后15分钟,在冷冻区出现肝细胞肿胀和小血管扩张充血.1天后,冷冻区出现白细胞;直径小于0.15毫米的小血管出现血栓栓塞.3天和7天后,坏死最严重;但是在坏死区四周已经出现肝组织再生.14天后坏死范围不断缩小,有纤维组织形成,并不断增生(围绕坏死区).到70天,只剩下很小的疤痕.本研究可为临床冷冻治疗提供参考依据.更多还原

【Abstract】 The freezing effect on rabbit liver after the treatment with liguid nitrogen(-190℃) was observed through a series of histological examinations. The cryosurgical probe was 6 mm in diameter and the freezing time was controlled in 3 minutes. The experiments showed that the rabbit tissue temperature dropped at the fastest rate within the first minute and sloved down thereafter. An ice ball with an average diameter of 21.4 mm was formed around the freezing site,and a temperature gradient occurred within the ice ball.Histalogical preparations of the treated liver tissues were obtained for examination from the rabbits on different time intervals after the freezing treatment. Swelling of the hapatic cells and congestion of small blood vessels were observed in 15 minutes after the freezing treatment. One day later, leucoeytes infiltration appeared in the freezing region, and throm-boembolism took place in small vessels. 3 to 7 days later, severe necrosis emerged at the treated area,but the regeneration of the hepatic tissues had arisen around the necrotic area. 14 days after the treatment, the necrosis area shrank gradually, and the fibrous tissue was formed and propagated. On about the 70th day, there left only a small sear in the freezing area. The study of these results would be a beneficial to the application in the clinical cryotherapy.更多还原