Effectiveness of Hepatic Arterial Embolization on Radiofrequency Ablation Volume in a Swine Model: Relationship to Portal Venous Flow and Liver Parenchymal Pressure

Purpose

To evaluate the effectiveness of transcatheter arterial embolization (TAE) on radiofrequency (RF) ablation volume and compare portal vein (PV) flow and liver parenchymal pressure before and after treatment.

Materials and Methods

Eight healthy female swine were divided into four groups to be treated with RF ablation alone (RF-only group), RF ablation after TAE with gelatin sponge particles (GSPs; RF/TAE group), RF ablation after TAE with Lipiodol plus GSPs (RF/TAE/Lipiodol group), and PV embolization (PVE) with GSPs after TAE with Lipiodol plus GSPs (RF/TAE/Lipiodol/PVE group). Five ablations were created in each swine, with 10 ablations per group. A 2-cm expandable LeVeen needle electrode was used for RF ablation.

Results

The greatest ablation volume (18,410.1 mm³ ± 3,986.4) was observed in the RF/TAE/Lipiodol/PVE group. Of the RF-only, RF/TAE, and RF/TAE/Lipiodol groups, the RF/TAE/Lipiodol group (14,835.5 mm³ ± 2,743.2) had a significantly larger ablation volume than the RF-only (8,002.6 mm³ ± 2,788.3) and RF/TAE groups (10,398.5 mm³ ± 2965.8; P < .05/3). PV pressures increased significantly after TAE (P < .01) compared with the pressure before TAE in the RF/TAE/Lipiodol and RF/TAE/Lipiodol/PVE groups, but not in the RF/TAE group. A marked increase in liver parenchymal pressure was seen during RF ablation; however, there were no significant differences among groups. Accumulation of Lipiodol was noted in the sinusoids in the RF/TAE/Lipiodol and RF/TAE/Lipiodol/PVE groups.

Conclusions

TAE with blockade of PV flow before RF ablation was associated with greater ablation volumes. Liver parenchymal pressure showed no correlation with increased ablation volume.

Abbreviations: GSP, gelatin sponge particle, PV, portal vein, PVE, portal vein embolization, RF, radiofrequency, TAE, transcatheter arterial embolization