湿电极单极针射频消融离体猪肝的实验研究

Experimental radiofrequency ablation in porcine liver ex vivo with ＂wet＂ unipolar electrode

目的探讨消融时间、温度、设定功率对RITA UniBlate湿电极单极针形成的消融灶的影响。方法观察湿电极单极针在离体猪肝射频消融实验时形成的消融灶形态特征，最大有效消融电极长度2．5cm，分别以时间、温度或功率为变量分A、B、C3个大组（11个亚组）进行实验，观察消融灶形态学特征，测量消融灶纵轴、横轴、针尖前端消融灶长度，计算消融灶体积，应用单因素方差分析法对上述4项指标进行统计学分析。用HE染色法对消融灶行病理学检查。结果（1）所有消融灶均呈椭球体。消融灶切面由内向外形成3个区：中心区、坏死区、出血水肿区。（2）当消融时间为15min、温度为103℃时消融灶达到最大，纵轴为（3．49±0．09）cm、横轴为（2．40±0．13）cm、体积为（10．6±1．3）cm^3，电极前端消融灶长度（0．79±0．09）cm；功率作为变量引起的消融灶大小变化差异无统计学意义。结论在一定时间、温度范围内，RITA UniBlate湿电极单极针消融灶大小随时间和温度的增加而增大；功率变化对消融灶大小没有影响。

Objective To observe the effects of radiofrequency ablation in porcine liver ex vivo with ＂wet＂ RITA UniBlate unipolar electrode, evaluate the morphologic characteristic of the ablated zones and explore the impact upon the ablation lesions of time, temperature and set power of ＂ wet＂ monopolar electrodes. Methods The maximal effective ablation electrode length of this ＂wet＂ unipolar electrode is 2.5 cm. According to ablation time, temperature and power respectively, the experiment was divided into three major groups of A, B, C （ 11 sub-groups）. The investigators observed the morphological characteristics of ablation lesions, measured the longitudinal and transverse distance of ablation beyond the electrode tip and calculated the volume of ablation lesion. Statistical analysis was performed with one-way ANOVA upon the above-mentioned four parameters. And the pathological examinations were made with HE staining. Results （ 1 ） All of ablated zones were ellipsoid. The cross-section of ablation lesions appeared to have 3 zones from the inside out： central zone, coagulated zone, hemorrhage and edema zone. （2） When ablating time and temperature increased to 15 min and 103 ℃ respectively, the ablated zones peaked： longitudinal diameter, transverse diameter, ablation distance beyond electrode tip and volume of each ablated zone was （3.49 ± 0. 09） cm, （2. 40 ±0. 13） cm, （0. 79 ±0. 09） cm and （ 10. 6 ± 1.3） cm^3 respectively. With power as a variable, different sizes between ablated zones showed no statistical significance. （3） The morphology of ablated zones became irregular when the electrodes were located around larger blood vessels. Conclusion The ablating time and temperature are the major factors of affecting the size of radiofrequency ablation lesion with RITA ＂wet＂ unipolar electrode.