不同循环冷冻消融术对西藏小型猪肝部冷冻消融效果的比较

A comparison of dual- and triple-freeze protocols for liver cryoablation in a Tibet pig

目的以西藏小型猪为模型，比较肝部双循环冷冻复温与三循环冷冻一复温消融效果的差异。方法西藏小型猪9头，开腹后行肝冷冻消融术。每头猪分别实施两循环冷冻一复温（10-5-10-5，min）消融和三循环冷冻一复温（5-5-5-5-10-5，min）消融，两组总冷冻时间相同。冷冻过程中分别测量冷冻中心点温度、冷冻形成冰球最大直径。术后7d取肝组织解剖、测量冷冻引起的表面损伤区最大长径及内部坏死区最大长径，并观察冷冻区域病理变化情况。结果三循环冷冻组形成的冰球表面最大长径大于两循环组；7d后两冷冻组冷冻后形成表面和深度损伤区大小相近。两循环冷冻组与三循环组冷冻损伤区病理分区相同，但三循环冷冻组引起完全坏死区域更大。结论相同的冷冻时间内，三循环冷冻组对肝脏的冷冻消融效果更好。

Objective This study compares a dual-freeze protocol with a triple-freeze protocol for hepatic cryoablation in the Tibetan pig model. Method Cryoablation with a dual- （10-5-10-5 min） and triple-freeze （5-5-5-5-10 5 min） protocol for the normal livers of 9 Tibet pigs was performed under exposed operation. Temperature changes of cryoprobes and diameter changes of iceballs were meas- ured during the ablation, and seven days later the pathological changes of cryozones were reviewed and the surface and depth cryolesions were measured. Results Compared with cryoablation with two freeze-thaw cycles, there was a greater iceball diameter for cryoablation by three freeze-thaw cycles. Also, seven days after cryosurgery, there were similar surface and deep cryolesions in dual- and triple- freeze protocols. Pathologically, the triple freezing protocol was associated with a longer zone of com- plete necrosis. Conclusions With the same freezing time （20 min）, the triple-freeze protocol may be- come a more powerful liver-ablation method in cryosurgical application.