We wanted to evaluate whether epinephrine injection prior to radiofrequency (RF) ablation can increase the extent of thermally mediated coagulation in vivo normal pig liver tissue.

Eighteen RF ablation zones were created in six pigs using a 17-gauge internally cooled electrode under ultrasound guidance. Three RF ablation zones were created in each pig under three conditions: RF ablation alone, RF ablation after the injection of 3 mL of normal saline, and RF ablation after the injection of 3 mL of epinephrine (1:10,000 solution). After the RF ablation, we measured the short and long diameters of the white zones in the gross specimens.

Three of the RF ablations were technically unsuccessful; therefore, measurement of white zone was finally done in 15 RF ablation zones. The mean short and long diameters of the white zone of the RF ablation after epinephrine injection (17.2 mm ± 1.8 and 20.8 mm ± 3.7, respectively) were larger than those of RF ablation only (10 mm ± 1.2 and 12.2 mm ± 1.1, respectively) and RF ablation after normal saline injection (12.8 mm ± 1.5 and 15.6 mm ± 2.5, respectively) (p < .05).

RF ablation with epinephrine injection can increase the diameter of the RF ablation zone in normal pig liver tissue.