多因素影响冷循环射频消融疗效的体外实验研究

目的探讨冷循环射频初始功率、射频时间、射频针等因素对消融效果的影响,评价超声判断消融区的价值。方法超声全程监控下对新鲜离体牛肝进行冷循环射频消融,单电极针作用下观察不同初始功率(80W、120W)和不同射频时间(5min、8min、10min)消融灶的实时演变过程,此外进行5min射频时间下不同初始功率(80W、120W)的集束针实验。实验结束后纵剖开标本,肉眼观察消融灶形态,并测量其大小,光学显微镜下观察消融灶病理学变化。结果肉眼测量消融灶显示:初始功率80W组消融灶随时间延长而增大,但扩展速度呈减缓趋势,初始功率120W组消融灶随时间扩大不明显;在射频时间较短的情况下初始功率120W组消融灶大于初始功率80W组,时间延长后两者差别缩小,射频时间达10min后两者形成大小相似的消融灶。集束针所形成消融灶的纵横比小于单电极针,剖面更接近圆形。超声显示强回声区范围与实际消融区有一定误差,纵径多大于实际,横径受声影遮盖难以测定,在大消融灶中往往小于实际。光学显微镜下消融区细胞形态、结构无明显变化。结论不同的射频时间和初始功率对冷循环射频消融能力有一定影响,高初始功率在增加产热的同时也降低热能传导,实际应用中应综合考虑。与单电极针相比,集束针形成的消融灶更接近实体肝肿瘤形态,对2cm左右的小肝癌疗效更可靠。超声可用于引导射频定位,但不能准确判定消融区边界。

Assessment of influence factors to curative effect in cool-tip radiofrequency ablation

Objective To investigate the effects of output power,action time and radiofrequency(RF) needle on the cool-tip radiofrequency ablation(RFA) by experimental tools and to determine the value of ultrasonography in size evaluation of RFA zone. Methods The cool-tip RFA to fresh calf liver were monitored by ultrasound. The experiments by single electrode needle were performed with different combination of output power (80 W,120 W) and time (5 min,8 min,10 min). The cluster needle was used for assessment at 5 min ...