Development of local necrosis, side-effects and histopathological study after hepatic injection of acetic acid solutions

Intratumoral injection of 50% acetic acid solution has recently been performed as a new local therapy for hepatocellular carcinoma. The use of ethanol in this therapy has problems of high dosage, frequent injections, and local tumor recurrence. Probably, in these regards the usefulness of acetic acid with potent coagulating and necrotizing effects cannot be denied. We have previously reported the acute toxicity of acetic acid injected into the normal rat liver at various concentrations. In the present study, we assessed the acute toxicity and necrotizing effect of 50% acetic acid solution and its effect on other organs after injection into the normal rat liver in different volumes. With increases in the volume of acetic acid, the size of the necrotic zone tended to increase and the mortality rate rose. The LD₅₀ of 50% acetic acid calculated with Behrens' method was 0.279 ml/kg. Histopathological examination of rats died immediately after acetic acid injection revealed acute pulmonary edema and marked congestion of the kidneys and spleen. Therefore, if this agent is used clinically, sufficient attention must be paid to its dose level and its acute toxicity.