Radiofrequency ablation with four electrodes as a building block for matrix radiofrequency ablation: Ex vivo liver experiments and finite element method modelling. Influence of electric and activation mode on coagulation size and geometry
| Autor: | Yicheng Ni, Tongfu Yu, Jacques Jamart, Y Miao, Luc Michel, Yansheng Jiang, Chong Wang, Kuirong Jiang, Guy Marchal, Yuanbo Feng, Ricardo Possebon, Stefaan Mulier |
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| Přispěvatelé: | UCL - (MGD) Service de chirurgie, UCL - SSS/IREC/MONT - Pôle Mont Godinne, UCL - (MGD) Unité de support scientifique |
| Rok vydání: | 2019 |
| Předmět: |
Finite element method
Radiofrequency ablation medicine.medical_treatment Finite Element Analysis Geometry 030218 nuclear medicine & medical imaging law.invention 03 medical and health sciences 0302 clinical medicine In vivo law medicine Animals Electrical impedance Electrodes Radiofrequency Ablation Matrix business.industry Liver Neoplasms Ablation Oncology Liver 030220 oncology & carcinogenesis Electrode Bipolar Surgery Cattle business Ex vivo Ablation zone |
| Zdroj: | Surgical Oncology, Vol. 33, p. 145-157 (2020) |
| ISSN: | 1879-3320 |
| Popis: | Purpose Radiofrequency ablation (RFA) is increasingly being used to treat unresectable liver tumors. Complete ablation of the tumor and a safety margin is necessary to prevent local recurrence. With current electrodes, size and shape of the ablation zone are highly variable leading to unsatisfactory local recurrence rates, especially for tumors >3 cm. In order to improve predictability, we recently developed a system with four simple electrodes with complete ablation in between the electrodes. This rather small but reliable ablation zone is considered as a building block for matrix radiofrequency ablation (MRFA). In the current study we explored the influence of the electric mode (monopolar or bipolar) and the activation mode (consecutive, simultaneous or switching) on the size and geometry of the ablation zone. Materials and methods The four electrode system was applied in ex vivo bovine liver. The electric and the activation mode were changed one by one, using constant power of 50 W in all experiments. Size and geometry of the ablation zone were measured. Finite element method (FEM) modelling of the experiment was performed. Results In ex vivo liver, a complete and predictable coagulation zone of a 3 × 2 × 2 cm block was obtained most efficiently in the bipolar simultaneous mode due to the combination of the higher heating efficacy of the bipolar mode and the lower impedance by the simultaneous activation of four electrodes, as supported by the FEM simulation. Conclusions In ex vivo liver, the four electrode system used in a bipolar simultaneous mode offers the best perspectives as building block for MRFA. These results should be confirmed by in vivo experiments. |
| Databáze: | OpenAIRE |
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