大鼠肝组织冷冻和射频灭活治疗对肺形态学和功能影响的比较实验研究

A comparative study on morphologic and functional changes in lung after cryoablation or radiofrequency ablation for liver tissue in rats

目的比较大鼠肝组织冷冻或射频治疗后对肺形态学和功能的影响。方法SD大鼠随机分成A（n=47）、B（n=32）两组，A组给予冷冻治疗，-196℃液氮浸泡冷冻，治疗时间15～20S；B组给予射频治疗，功率15w，时间60～90s。按预定时间处死。术前、术后1、3、6、24h ELASA检测血TNF-α，IL=8；同时观察肺组织学表现和早期死亡率。结果术后，A组血TNF-α，IL-8浓度1h显著升高，3h达峰值；B组仅轻微的升高（A与B组相比：P＜0．01）。A组光镜下可见肺组织间隔明显增厚，充血，水肿，灶性肺实质出血，大量的中性粒细胞，巨噬细胞浸润；而B组肺部仅有少量的炎细胞浸润。另外，术后48h内死亡率，A组为25．5％；B组仅为5．4％，差异显著（P＜0．05）。结论相同条件下，冷冻治疗引起了急性肺损伤、高死亡率等并发症，而射频治疗影响轻微。在一定条件下，射频是相对安全的。

Objective To compare the morphologic and functional changes in lung after cryoablation（CA）or radiofrequency ablation（RFA）for liver tissue in rats. Methods In this study, seventynine Sprague-Dawley rats were randomized into 2 groups. Rats in group A（n=47）was treated with cryoablation by liquid nitrogen, which was performed in 15 ～20 s. Animals in group B（n =32）was treatment with RFA by using a cooled-tip technique. The energy output was 15 W× （60～90）s. All rats were sacrificed at prescheduled time and then the serum and tissue samples from the lung were collected for subsequent analysis. Serum concentrations of tumor necrosis factor-α（TNF-α）and interleukin-8（IL-8）were measured by enzyme-linked immunosorbent assay（ELISA）before and 1, 3, 6, and 24 h after ablation. Histological features of lung tissue and death in early stage were compared between the 2 groups. Results In group A, serum TNF-a and IL-8 levels were markedly increased in rats 1 h after hepatic ablation as compared with group B（P〈0.01, group A vs B）. They peaked at 3 h and returned to baseline after 24 h. Histologic lung sections after cryoablation showed local parenchymal hemorrhage and multiple foci of perivenular inflammation, with activated foamy macrophages and neutrophils. In animals undergoing RFA, inflammation foci were slight. In addition, cryoablation of liver resulted in a 25.5% mortality rate within 48 h of treatment, whereas 5.4% treated in RFA group（P〈0.05）. Conclusion Hepatic tissue cryoablation results in a series of severe side effects including acute lung injury and high mortality. However, an approximate volume of liver parenchyma undergoing RFA induces a light impact, which could be a safe therapy for liver tumor.