Nakada Stephen Y, Jerde Travis J, Warner Thomas F, Wright Andrew S, Haemmerich Dieter, Mahvi David M, Lee Fred T
Department of Surgery, Division of Urology, University of Wisconsin Medical School, G5/339 Clinical Science Center, 600 Highland Avenue, Madison, WI 53792-3236, USA.
J Endourol. 2003 Dec;17(10):927-33. doi: 10.1089/089277903772036316.
We report initial ex vivo and in vivo studies using bipolar radiofrequency (RF) ablation of porcine kidneys. An internal ground electrode is positioned in the kidney opposite the RF electrode, resulting in ablation of all the intervening renal tissue.
Ex vivo preparations of 10 porcine kidneys were perfused continuously with Ringer's solution and treated with either standard external grounded RF (N = 3) or bipolar RF ablation with 1 (N = 2), 2 (N = 3), or 3 (N = 2) cm of separation between the ground probe and the RF probe using a Model 30 RITA generator (RITA, Mountain View, CA). Target temperatures were 90 degrees C for 8 minutes. Gross and histologic assessments were made acutely. Four domestic pigs were treated with monopolar RF ablation of the lower pole of one kidney and bipolar RF with a 12-mm separation between the probes of the contralateral lower pole. Animals were harvested 48 hours later to maximize tissue damage for gross measurements and histologic evaluation.
Ex vivo studies revealed grossly monopolar lesions 1.5 cm in maximum diameter and 1.75 cm(3) in volume. In comparison, bipolar lesions were 2.8 cm in maximum diameter and 10.3 cm(3) in volume using 3 cm of electrode separation. There was histologic evidence of cell death in all specimens. In vivo studies showed two distinct gross lesions with RF: one blanched and one hemorrhagic. Using bipolar RF, larger blanched lesions were achievable than with monopolar RF (2.80 cm(3) v 1.63 cm(3)). Overall, the combinations of blanched and hemorrhagic lesions were similar with monopolar and bipolar RF (5.01 v 5.31 cm(3)). Histologic evaluation verified cell death in the blanched lesions and rare areas of normal tissue in the hemorrhagic lesions.
As shown by ex vivo data, bipolar RF can create larger lesions than does monopolar RF. In vivo, at 48 hours, both blanched and hemorrhagic gross lesions were seen using RF. In this model, blanched lesions predominated when performing bipolar RF.
我们报告了使用双极射频（RF）消融猪肾脏的初步离体和体内研究。在肾脏中与RF电极相对的位置放置一个内部接地电极，从而消融所有中间的肾组织。
用林格氏液持续灌注10个猪肾的离体标本，并用标准外部接地RF（N = 3）或使用30型RITA发生器（RITA，加利福尼亚州山景城）进行双极RF消融，接地探头与RF探头之间的间距分别为1 cm（N = 2）、2 cm（N = 3）或3 cm（N = 2）。目标温度为90摄氏度，持续8分钟。进行急性大体和组织学评估。对4只家猪，一侧肾脏下极采用单极RF消融，对侧肾脏下极探头间距为12 mm采用双极RF消融。48小时后处死动物，以使组织损伤最大化，用于大体测量和组织学评估。
离体研究显示，单极病变最大直径为1.5 cm，体积为1.75 cm³。相比之下，使用3 cm电极间距时，双极病变最大直径为2.8 cm，体积为10.3 cm³。所有标本均有细胞死亡的组织学证据。体内研究显示，RF有两种不同的大体病变：一种发白，一种出血。使用双极RF时，可获得比单极RF更大的发白病变（2.80 cm³对1.63 cm³）。总体而言，单极和双极RF的发白和出血病变组合相似（5.01对5.31 cm³）。组织学评估证实发白病变中有细胞死亡，出血病变中有罕见的正常组织区域。
如离体数据所示，双极RF可产生比单极RF更大的病变。在体内，48小时时，使用RF可见发白和出血两种大体病变。在该模型中，进行双极RF时发白病变占主导。
