HEPATIC ABLATION USING BIPOLAR RADIOFREQUENCY ELECTROCAUTERY

Rationale and Objectives. Percutaneous methods have been used to treat primary and secondary hepatic neoplasms. In the current study, we eva luated the potential of bipolar radiofrequency (RF) electrocautery to increase in vitro liver tissue destruction when com pared with monopol ar RF electrocautery. Methods. Two needles (electrodes) were placed in to fresh bovine liver tissue for use with bipolar electrocautery. Need le tip exposure was kept constant at 3 cm while other parameters, incl uding treatment time, power (wattage), interneedle distance, and needl e tip temperature: were changed. Pathologic and histologic correlation was performed, and tissue necrosis was weighed in grams for individua l parameters. Results. There was a minimal threshold of approximately 45 degrees C where tissue coagulation occurred. Tissue coagulation inc reased the longer treatment went on. Increasing temperature, wattage, or both increased tissue coagulation such that necrosis was too rapid and char formation occurred, which prevented further coagulation. For all wattages and temperatures, there was increasing tissue necrosis wi th increasing needle separation, until a point at which further needle separation produced less tissue necrosis. Optimizing parameters allow ed tissue coagulation of greater than 30 g. Conclusion. Bipolar RF ele ctrocautery shows promise for increasing the tissue coagulation in fre sh bovine liver compared with the previously described monopolar techn ique.