Purpose: Acetic acid has been employed as a chemical ablation agent for liver tumors because of its superior diffusion characteristics compared with ethanol and the resulting requirement for smaller volumes and fewer injection sessions. Early tissue changes were compared after injection of acetic acid and ethanol in a rabbit model of hepatocellular carcinoma.
Materials and methods: VX2 tumors were created in the left lobe of the liver in 11 male New Zealand White rabbits. Each animal underwent a midline minilaparotomy to expose the tumor-laden left lobe, followed by injection of 1.0 mL of 100% ethanol (n = 5) or 50% acetic acid (n = 6) with use of a 20-gauge infusion needle. Animals were killed 30 minutes after surgery; explanted livers were sectioned and examined for gross and microscopic changes.
Results: Injection of each agent produced rapid diffusion through tumor and surrounding hepatic parenchyma, with immediate protein precipitation manifested by blanching as a result of coagulation effect. The sizes of coagulation zones, expressed as mean products of the maximum perpendicular diameters of tumoral diffusion, were 13.0 cm(2) +/- 9.4 and 1.3 cm(2) +/- 1.8 for acetic acid and ethanol, respectively (P =.049). No differences in histologic changes were seen between agents.
Conclusions: In this animal model, acetic acid produced significantly larger zones of tumor coagulation compared with ethanol when injected into VX2 carcinoma in equal volumes. Further evaluation is necessary before these findings can be extrapolated to a clinical setting.