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CardioVascular and Interventional Radiology

, Volume 34, Issue 3, pp 631–636 | Cite as

Direct Current Combined With Bipolar Radiofrequency Ablation: An Ex Vivo Feasibility Study

  • Toshihiro Tanaka
  • Tobias Penzkofer
  • Peter Isfort
  • Philipp Bruners
  • Catherine Disselhorst-Klug
  • Elmar Junker
  • Kimihiko Kichikawa
  • Thomas Schmitz-Rode
  • Andreas H. Mahnken
Technical Note
  • 145 Downloads

Abstract

The combination of radiofrequency ablation (RFA) with direct current (DC) is a promising strategy to improve the efficiency of RFA. However, DC-enhanced monopolar RFA is limited by electrolytic injury at the positive-electrode site. The aim of this study was to investigate the feasibility of the DC-enhanced bipolar RFA. To obviate the need for the subcutaneous positive electrode, the DC circuit was combined with a commercially available bipolar RFA system, in which both poles of the DC circuit are connected to a single RF probe. DC was applied for 15 min and followed by RFA in bovine livers using the following various DC currents: (1) no DC (control), (2) 3V continued until the end of RFA, (3) 5V continued until the end of RFA, (4) 10V continued until the end of RFA, (5) 5V continued in the circuit with reversed pole, (6) 3V stopped after initiation of RFA, and (7) 5V stopped. Coagulation volume, temperatures at a distance of 5, 10, and 15 mm from the RF probe, mean amperage, ablation duration, applied energy, minimum impedance, and degree of tissue charring were assessed and compared (analysis of variance, Student–Newman–Keuls test). All combined DC and RFA groups did increase coagulation volume. The 10V continued group showed significantly lower applied energy, shortest ablation duration, highest minimum impedance, and highest degree of charring with the lowest coagulation volume (p < 0.05). DC-enhanced bipolar RFA with both poles of the DC circuit on a single probe appears to be ineffective.

Keywords

Radiofrequency ablation Liver tumor Direct current 

Notes

Acknowledgments

The authors acknowledge the excellent technical support of So-Hyun Park and Dennis Faßbänder.

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Copyright information

© Springer Science+Business Media, LLC and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2010

Authors and Affiliations

  • Toshihiro Tanaka
    • 1
    • 3
  • Tobias Penzkofer
    • 1
    • 2
  • Peter Isfort
    • 1
    • 2
  • Philipp Bruners
    • 1
    • 2
  • Catherine Disselhorst-Klug
    • 1
  • Elmar Junker
    • 1
  • Kimihiko Kichikawa
    • 3
  • Thomas Schmitz-Rode
    • 1
  • Andreas H. Mahnken
    • 1
    • 2
  1. 1.Applied Medical Engineering, Helmholtz-Institute AachenRWTH Aachen UniversityAachenGermany
  2. 2.Department of Diagnostic Radiology, Aachen University HospitalRWTH Aachen UniversityAachenGermany
  3. 3.Department of RadiologyNara Medical UniversityKashiharaJapan

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