[Selective segmental necrotizing therapy for hepatocellular carcinoma: an experimental study of an ethanol injection method].

Selective segmental necrotizing therapy (SSN), which necrotizes the hepatic segment by ethanol injection through the intrahepatic portal vein under balloon occlusion, is a new treatment for hepatocellular carcinoma. To better perform this therapy safely and completely, the author examined an ethanol injection method using rabbits. A discolored area immediately formed in the injected area following rapid injection (injection speed > or = 1.0 ml/s) of absolute ethanol. This area became larger with increasing ethanol volume until it reached a plateau. The author defined the minimal volume as the minimal ethanol volume needed to form the maximal discolored area. The minimal volume correlated with the portal branch diameter of the injected area. A discolored area also formed when 50% or 25% ethanol was given by slow injection (injection speed < or = 0.1 ml/s), similar to the case of using absolute ethanol by rapid injection. The area was recognized as a necrotic area on histological examinations 14 days after SSN. The blood ethanol level in the right atrium showed the slightest elevation when 25% ethanol was given by slow injection. GPT showed the highest elevation 1 day after SSN, but it returned to normal 7 days after SSN in all ethanol injection methods. From these results, the author concluded that SSN should be performed using 25% ethanol by slow injection.