Sonographically guided radiofrequency ablation with and without a superficial saline injection to prevent skin burns in a rabbit model

Objectives - Our aim was to determine whether sonographically guided radiofrequency ablation with superficial saline injection can minimize thermal injury of the skin without an influence on therapeutic efficacy. Methods - Institutional Animal Care Committee approval was obtained. Twelve percutaneous radiofrequency ablation procedures were performed in the thighs of 6 rabbits (control, n = 6, right thigh; experimental, n = 6, left thigh). The ablation with local anesthesia was performed in the most superficial area of the thigh muscle. In the experimental group, 1 mL of saline was injected before the ablation at the tissue layer between the skin and ablated muscle. The duration and energy of the ablation were the same in the control and experimental groups. Rabbits were compared for their gross skin state and histopathologic findings after the ablation. Results - The degree of thermal coagulation of the muscle was similar in both groups at pathologic examination. Grossly, skin redness was mild in the experimental group but moderate in the control group. Of the 6 rabbits, 5 tended to show more frequent histopathologic changes, including an inflammatory reaction, interruption of collagen fibers, injury of the skin adnexa, and fibrosis, in the control group when compared with the experimental group. However, there was no statistically significant difference (all P > .05). One rabbit that underwent ablation at higher energy had a partially dissected epidermis in the control group only. Conclusions - Sonographically guided radiofrequency ablation with a saline injection superficial to a tumor might prevent skin burns and provide equivalent therapeutic efficacy for ablating superficial lesions.