Experimental radiofrequency ablation near the portal and the hepatic veins in pigs: differences in efficacy of a monopolar ablation system.
BACKGROUND
We sought to compare the efficacy of a monopolar radiofrequency ablation system in vivo near the portal vein and the hepatic veins in porcine liver.


METHODS
Radiofrequency ablation of healthy livers near the portal vein and the hepatic veins was performed in 10 pigs with a multitined expandable electrode. Volumes and diameters of zones of ablation were assessed by magnetic resonance imaging.


RESULTS
Volumes (16.0 +/- 5.5 mL, P = 0.001) and diameters (4.0 +/- 0.7 cm, 3.3 +/- 0.7 cm, 3.0 +/- 0.6 cm, P <or= 0.05) of the zones of ablation near the hepatic veins were larger than that near the portal vein (7.5 +/- 4.1 mL, 3.2 +/- 0.7 cm, 2.6 +/- 0.7 cm, 2.4 +/- 0.6 cm). Energy deposition needed to ablate liver tissue was higher (P = 0.003) for radiofrequency ablation near the portal vein (3.16 +/- 1.58 kJ/mL) than for radiofrequency ablation near the hepatic veins (1.65 +/- 1.14 kJ/mL).


CONCLUSIONS
Higher energy deposition is needed to ablate liver tissue near the portal vein than near the hepatic veins. As a result, the zone of ablation is larger near the hepatic vein than near the portal vein.
Bangard
Christopher
C
Department of Radiology, University of Cologne, Cologne, Germany. cbangard@gmx.de
Gossmann
Axel
A
Kasper
Hans U
HU
Hellmich
Martin
M
Fischer
Jürgen H
JH
Hölscher
Arnulf
A
Lackner
Klaus
K
Stippel
Dirk L
DL