The operation and efficacy of cryosurgical, nitrous oxide-driven cryoprobe. I. Cryoprobe physical characteristics: their effects on cell cryodestruction.
The operation and efficacy of cryosurgical, nitrous oxide-driven cryoprobe. I. Cryoprobe physical characteristics: their effects on cell cryodestruction.
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一氧化二氮驱动冷冻探头冷冻手术的操作和功效。
DOI：
10.1006/cryo.1994.1035
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发表时间：
1994
期刊：
影响因子：
2.7
通讯作者：
O. Maiwand
中科院分区：
文献类型：
--
作者：
J. Homasson;J. Thiery;M. Angebault;L. Ovtracht;O. Maiwand
为了说明有效冷冻破坏肿瘤细胞的要求，我们在实验模型上测试了一种由N2O驱动的冷冻探头。冰冻探头直径3 mm，用于呼吸内科的纤维支气管镜手术。冰冻过程，即在低温探头尖端形成的“冰球”，是用阻抗测量仪监测的。在一定的实验条件下，研究了冰球在生理盐水、血清、全血和肿瘤细胞悬液(大鼠腹水型肝癌)中形成的物理特征和形成动力学(体积、直径、冻结率)。对大鼠腹水型肝癌产生的冰球内的细胞破坏(即对细胞的冷冻毒性)以两种方式进行评估：冰球解冻后收集的细胞被(1)按目前使用的方法接种并培养，或(2)注射到大鼠体内以检查可能的腹水发展。两种试验都表明，冰球内的冷冻毒性与冰球内的冻结速度有关，细胞死亡率在冰球尖端(即冰冻速度最高的部位)附近是总的，而在冰球外围没有。在这两者之间的区域，死亡率逐渐变化。总而言之，我们的实验结果表明，提高冷冻速度(例如，通过短暂预冷冷冻探头)可以改善对细胞的冷冻毒性。此外，对于肿瘤冷冻手术，由于细胞死亡率仅次于冷冻探头，我们指出，在肿瘤组织中使用几个重叠的短冰冻点可能比单一的长时间冷冻效果更好。
For specification of the requirements for efficient cell cryodestruction in tumors, we tested a N2O-driven cryoprobe on experimental models. The cryoprobe was a 3-mm-diameter type for operation via fiber optic bronchoscopes in respiratory medicine. The freezing process, namely the "ice-ball" formation around the cryoprobe tip, was monitored with an impedancemeter. Physical characteristics and formation kinetics of the ice-ball formation (volume, diameter, freezing rate) were studied under defined experimental conditions in various biological liquids, including saline, serum, whole blood, and tumor cell suspensions (rat ascitic hepatoma), either plain or supplemented with gelling agents to approximate solid tumor consistency. Cell destruction (i.e., cryotoxicity to cells) within the ice ball produced in rat ascitic hepatoma was assessed in two ways: the cells, collected after ice-ball thawing, were (1) seeded and cultured according to methods currently in use, or (2) injected into a rat to check for possible development of ascites. Both tests showed that cryotoxicity correlated with freezing rate within the ice ball, cell mortality was total next to the cryoprobe tip (i.e., site of highest freezing rate), while it was absent within the ice-ball periphery. In the area in between, mortality varied gradually. Together our experimental results show that cryotoxicity to cells may be improved by increasing the freezing rate (e.g., by brief precooling of the cryoprobe). Furthermore, for tumor cryosurgery, since cell mortality is maximal next to the cryoprobe, we point out that higher efficacy might be achieved by several overlapping short freezing spots in tumoral tissue, instead of one single prolonged freeze.