多电极射频对离体动物肾脏作用的研究

目的了解多电极射频对离体动物肾脏的作用、初始功率对消融灶的影响和超声在评估消融灶大小的应用价值.方法取新鲜离体动物肾脏4枚,在其上、下极和中部进针1cm,12个靶点随机分两组,每组6个,分别应用5W和10W的初始功率进行消融,用实时超声、4小时后超声和肉眼病理对比观察.结果消融灶稍大于电极伞径,初始功率不同所产生的消融灶大小差异无显著性.超声显示消融灶为边缘极不规则的强回声,肉眼观察呈棕褐色类圆形的凝固性坏死.实时超声测值和肉眼解剖测值差别有显著意义.4小时后超声值和肉眼测值在冠状面和横断面最大径差异无显著性,但在消融深度差异有极显著意义.结论消融灶的大小不随功率增加而增大,实时超声不能反映消融灶的大小,延时超声所测消融深度较实际值小.根据伞径预测消融灶的大小是可靠的.

The experiment in vitro of using interstitial radiofrequency thermoablation for animal kidney

Objective To evaluate the effcacy of radio-frequency (RP) ablation in vitro for animal kidney and investigate the relationship between the size of the ablation lesion and the initial power, the size measured with ultrasonography and gross examination. Methods Four porcine kidneys away from body were elected, a 8- electrode dry radiofrequency thermal ablation probe was inserted into superior pole, lower pole and middle part of each kidney at the depth of 1 cm from surface, respectively. Then the probe was deployed to a diameter of 2 cm. 12 targets were divided into two groups averagely, initial power was applied for 5 watt and 10 watt, respectively. Impedance come up to a head was taken for the end poine of RF ablation. The ablation lesion was monitored with ultrasonography during and after experiment and the size and shape of the lesions created were measured and examined histologically. Results Ultrasonography conf rmed probe placement but did not monitor leison progression, the irregular hyperechogenicity was shown on ultrasound screen. There was significant difference for the measuring value between real-time ultrasound and the gross examination. All lesions were rounded brown after ablation, in contrast to the normal pinkappearance of (?)ntreated parts. The size of ablation lesion was not related to the initial power, but similar to a diameter of the probe. Conclusion In the porcine kidney away from body RF ablation created rapid and completely devitalized lesion of consistent size and shape, the size of lesion was in accordance with the diameter of the probe, bu did not increase with the increase of the initial power. The value of the ablative lesion in real-time ultrasonogrphy was bigger than that measured in pathomorphology, the ablative depth in delay ultrasonography was smaler than that in pathomorpholo-gy.