国产冷冻设备(靶向刀)消融活体猪肝的实验研究

Experimental study on cryoablation of pig liver in vivo with domestic cryoablation device

目的比较国产冷冻设备(靶向刀)1次冷-热循环和2次冷-热循环的消融范围及实际坏死范围的差异。方法 4只小型巴马猪(25~30 kg),随机分为A、B两组,麻醉后开腹暴露肝脏,放置冷冻针于合适肝叶部位进行冷冻消融,A组选择冷-热(10~3 min)1次循环模式,B组选择冷-热(10~3 min)2次循环模式。冷循环结束后扫描CT,计算机多平面重建(MPR)描绘出椭球形冰球的最大宽径。术毕处死小型猪,取出靶区肝脏标本,固定48 h后,沿着冷冻针穿刺道垂直方向沿消融区域冰球的最大宽径处切开标本,石蜡包埋切片后进行HE及末端脱氧核苷酸转移酶-生物素dUTP切口末端标记法(TUNEL)染色。观察消融区域病理学改变,使用Toup View显微镜图像测量软件测量TUNEL染色下坏死区域的边界与针道的距离。结果 1次循环冰球的最大宽径为(27.6±0.9) mm,2次循环的冰球的最大宽径为(31.4±0.5) mm(P<0.01)。1次循环冰球覆盖范围内实际坏死的边界距冰球覆盖范围的边界距离为(5.6±0.5) mm,2次循环冰球覆盖范围内实际坏死的边界距冰球覆盖范围的边界距离为(3.2±0.2) mm (P<0.01)。结论对于国产冷冻设备(靶向刀) 2次循环较1次循环冰球形成范围更大,且实际坏死区域明显增大,而消融边缘更小。当前2次冷-热循环的消融方案治疗肝脏肿瘤,至少要保证冰球要覆盖病灶周围正常肝脏组织3.5 mm以上才足够。

Objective To compare the differences in ablation range and actual necrosis range between a single freezing-rewarming cycle treatment and twice freezing-rewarming cycles treatment with the domestic cryoablation device(target knife, Accu Target). Methods Four small Obama pigs(25-30 kg) were randomly and equally divided into group A and group B. Under general anaesthesia, laparotomy was performed to expose the liver. The cryoprobe was inserted in a suitable hepatic lobe to make cryoablation. For experimental pigs of group A the cryoablation treatment with a single freezing-rewarming(10 min and 3 min respectively) cycle treatment was adopted, while for experimental pigs of group B twice freezingrewarming(10 min and 3 min respectively) cycles treatment was carried out. After the treatment, CT scan was performed and the maximum width size of ellipsoid ice-ball was outlined with multiplanar reconstruction(MPR) technique. The pigs were sacrificed after the procedure, and the target liver specimens were taken out and fixed for 48 hours. Along the vertical direction of the frozen needle puncturing track at the maximum width site of the ellipsoid ice-ball the specimens were cut apart. The sections of specimens were embedded in paraffin and HE staining and TUNEL staining were performed. Pathological changes in ablated area were documented. Toup View microscope image measurement software was used to measure the boundary of necrotic area with TUNEL staining, and the distance between boundary and needle track was measured. Results The maximum width of the ice-ball was(27.6±0.9) mm in group A, which was(31.4±0.5) mm in group B, the difference between the two groups was statistically significant(P<0.01). The distances between the border of actual necrotic area and the edge of ice-ball in group A and group B were(5.6±0.5) mm and(3.2±0.2) mm respectively, the difference between the two groups was statistically significant(P<0.01). Conclusion In performing cryoablation therapy with domestic cryoablation device(target knife), the twice freezing-rewarming cycles treatment can produce bigger ice-ball, larger actual necrotic area and smaller ablation border than single freezing-rewarming cycle treatment does. When twice freezing-rewarming cycles treatment is adopted for hepatic tumor, it is essential to ensure that the ice-ball should cover the normal liver tissue around the lesion more than 3.5 mm.