目的：在离体猪甲状腺组织上比较微波消融（MWA）、射频消融（RFA）、激光消融（LA）的消融特性和温度变化，为临床制定消融方案提供参考。方法：将150个新鲜离体猪甲状腺均分为3组，分别行MWA（20 W 5 min）、RFA（5 W）、LA（3 W 1200 J），各组消融同时在靶心处进行实时测温和超声观察，消融结束后沿针道剖开，观察消融灶形态，计算消融灶体积并进行病理学检查。结果：3组间比较，MWA组消融体积最大（1 597.09 mm3），LA组次之（780.89 mm3），RFA组最小（162.20 mm3），差异均有统计学意义（均P<0.05）。MWA及RFA温升曲线陡直，而LA温升曲线平缓，但最高温度最高（200.9 ℃）。RFA组消融区域组织分布均匀，未见到明显的炭化和气化空腔；MWA组消融区域可见碳化，但无明显气化空腔；LA组消融灶中央可见碳化与气化空腔。消融灶由内向外，RFA组为凝固坏死区、充血反应区；MWA组为炭化区、凝固坏死区及充血反应区；LA组为气化空腔区、炭化区、凝固坏死区及充血反应区。结论：MWA、RFA及LA的消融范围、温升曲线及消融区病理变化存在差异，了解各自的消融特点有利于3种消融技术的合理应用。
Comparative experiment of microwave, radio frequency and laser ablation of pig thyroid in vitro
Objective: To compare the ablation features and variations among microwave ablation (MWA), radiofrequency ablation (RFA) and laser ablation (LA) in pig thyroid in vitro, so as to provide reference for clinical decision-making. Methods: One hundred and fifty freshly harvested pig thyroid glands were equally divided into 3 groups, and then underwent MWA (20 W 5 min), RFA (5 W) and LA (3 W 1200 J), respectively. In each group, the real-time temperature at the target area was measured and real-time ultrasound observation was conducted during ablation procedure, and after ablation, the specimens were cut open along the needle passage, and the gross appearance was observed, ablation volume was determined and pathological examination was performed. Results: Comparison among the three groups showed that the ablation volume was largest in MWA group (1 597.09 mm3), followed by LA group (780.89 mm3), and was smallest in RFA group (162.20 mm3), and the difference between either of them had statistical significance (all P<0.05). The temperature rise curve of MWA or RFA was swift and steep, and that of LA was gentle and long, but its maximum temperature was highest (200.9 ℃ ). In ablation zone, no evident tissue destruction as well as carbonization and vaporization cavity was seen in RFA group, carbonization but no vaporization cavity was found in MWA group, and both carbonization and vaporization cavity presented in LA group. The ablation lesion from inside to outside presented coagulation necrosis and congestion reaction zone in RFA group, was carbonization, coagulation necrosis and congestion reaction zone in MWA group, and was vaporization cavity, carbonization, coagulation necrosis and congestion reaction zone in LA group, respectively. Conclusion: The ablation scope, temperature rise curve and pathological changes in the ablation zone are different among MWA, RFA and LA, and understanding their characteristics may be helpful to the rational use of these three ablation techniques.