bipolar radiofrequency

Bipolar Radiofrequency

Afshin Gangi MD, PhD. Stephane Guth MD. Jean-Pierre Imbert

( ECR 2003 Cum Laude )

A special note of gratitude goes to Stephen Ferron, Irving Freedmann and Petra Gangi for checking the presentation

Abstract

Radio-frequency (RF) ablation has become an important means of treatment of nonresectable primary and metastatic tumors. Major limitations are small lesion size, which make multiple applications necessary, incomplete killing of tumor cells, resulting in high recurrence rates, and risk of damage to adjacent structures (bowel, nerve root). We examined a new bipolar RF ablation method incorporating two probes with perfused needle electrodes (Berchtold®). We performed bipolar ex vivo experiments on five beef livers. The electrodes were 3 cm apart. We used impedance-controlled mode. Lesion volumes were 16.5 cm3 ex vivo and 12.5 in vivo. The bipolar method creates faster, larger, more predictible lesions. It is less dependent on local inhomogeneity in liver tissue compared with monopolar RF ablation. A limitation of the bipolar method are: the power dissipation of the two probes that cannot be controlled independently in response to different conditions in the vicinity of each probe, insertion of two probes, and the maximum probes interval is limited to 3 cm.