Radiofrequency tissue ablation: Effect of hepatic blood flow occlusion on thermal injuries produced in cirrhotic livers

Background: Radiofrequency thermal ablation has been used as a treatment for several types of hepatic malignancies. Many of these lesions exist in the presence of cirrhosis. Limitations exist to the size of the ablations and, subsequently, the efficacy of treatment. Hepatic vascular inflow occlusion has been advocated as an adjunctive measure to increase the efficacy of the ablation. We present a model in the human cirrhotic liver that demonstrates the advantage of blood flow occlusion during radiofrequency ablation. Methods: Five patients with advanced endstage liver disease scheduled to have orthotopic liver transplantation were enrolled in this study. After laparotomy and before hepatectomy, radiofrequency ablation was performed without and with hepatic blood flow occlusion. After hepatectomy, the liver was sectioned, the area of ablation was measured in three dimensions, and the volume of ablation calculated. Results: Three of the patients had had previously placed transjugular intrahepatic portosystemic shunt. The mean volume of the ablation without blood flow occlusion was 22.5 +/- 7.4 cm(3) and that with blood flow occlusion was 48.4 +/- 24.0 cm(3) (P = .05). Conclusions: Ablation area is increased significantly with hepatic blood flow occlusion in the human cirrhotic liver. This result may have application in the treatment of larger (>3 cm) hepatic malignancies.