Optimization of Direct Current–Enhanced Radiofrequency Ablation: An Ex Vivo Study

被引:0
作者
Toshihiro Tanaka
Peter Isfort
Philipp Bruners
Tobias Penzkofer
Kimihiko Kichikawa
Thomas Schmitz-Rode
Andreas H. Mahnken
机构
[1] RWTH Aachen University,Applied Medical Engineering, Helmholtz
[2] Aachen University Hospital,Institute Aachen
[3] RWTH Aachen University,Department of Diagnostic Radiology
[4] Nara Medical University,Department of Radiology
来源
CardioVascular and Interventional Radiology | 2010年 / 33卷
关键词
Radiofrequency ablation; Liver tumor; Direct current;
D O I
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学科分类号
摘要
The purpose of this study was to investigate the optimal setting for radiofrequency (RF) ablation combined with direct electrical current (DC) ablation in ex vivo bovine liver. An electrical circuit combining a commercially available RF ablation system with DC was developed. The negative electrode of a rectifier that provides DC was connected to a 3-cm multitined expandable RF probe. A 100-mH inductor was used to prevent electrical leakage from the RF generator. DC was applied for 15 min and followed by RF ablation in freshly excised bovine livers. Electric current was measured by an ammeter. Coagulation volume, ablation duration, and mean amperage were assessed for various DC voltages (no DC, 2.2, 4.5, and 9.0 V) and different RF ablation protocols (stepwise increase from 40 to 80 W, 40 W fixed, and 80 W fixed). Results were compared using Kruskal–Wallis and Mann–Whitney U test. Applying DC with 4.5 or 9.0 V, in combination with 40 W fixed or a stepwise increase of RF energy, resulted in significantly increased zone of ablation size compared with 2.2 V or no DC (P = 0.009). At 4.5 V DC, the stepwise increase of RF energy resulted in the same necrosis size as a 40 W fixed protocol (26.6 ± 3.9 vs. 26.5 ± 4.0 ml), but ablation duration was significantly decreased (296 ± 85 s vs. 423 ± 104 s; P = 0.028). Mean amperage was significantly lower at 4.5 V compared with 9.0 V (P = 0.028). Combining a stepwise increase of RF energy with a DC voltage of 4.5 V is most appropriate to increase coagulation volume and to minimize procedure time.
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页码:1028 / 1032
页数:4
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