Percutaneous rediofrequency ablation for malignant liver tumor during hepatic blood flow

Abstract

Radiofrequency ablation (RFA) therapy under interruption of the hepatic blood flow was performed on four patients with hepatocellular carcinoma and on one patient with primary malignant hepatic lymphoma. In this therapy, radiofrequency (RF) waves are delivered, while the hepatic artery is selectively blocked with gelatin sponge and the hepatic vein is selectively blocked with a balloon catheter. The RF wave generation device and electrodes used were 460kHz Leven needle electrode 26-207 (Boston scientific, Tokyo Japan), 2 mm in diameter, with 8 umbrella-shaped needles, and development widths of 20 mm and 30 mm were used. RF waves of 40W or 50W were delivered until roll off occurred or for up to 20 minutes. The patients were put under epidural anesthesia and additional local anesthesia. Efficacy judgment was made based on the postoperative dynamic CT findings. Tumors, in the range of 25 to 60 mm in diameter, could be coagulated in one session of therapy for all the patients except one. In 2 patients with hepatocellular carcinoma of 38 mm in diameter who underwent RFA with only hepatic artery interruption, dynamic CT immediately after the irradiation revealed peripheral shadow defect of the tumor. However, the portal blood flow in the tumor and the hepatic blood flow in the center of coagulation were detected. Dynamic CT at week 1 post-irradiation revealed no deep staining, indicating complete coagulation. No portal blood flow in the tumor was observed in the patients except in the aforementioned two cases.The findings that coagulation by RFA of the hepatic tumors controlled the hepatic blood flow, and the portal blood flow in particular, indicated that RFA therapy could allow strong heat coagulation of the tumor itself in addition to expansion of the coagulation area.