Radiofrequency ablation of hepatic tissue: a new experimental animal model.
OBJECTIVE
Experimental radiofrequency ablation has already been performed in healthy livers of porcine models, but not in less expensive and easy-to-manage rats, with devices capable of delivering radiofrequency ablation in the 20-30 g liver of such small animals being so far unavailable.


METHODS
We experimented with a modified system of radiofrequency ablation of liver tissue in rat models developing a custom-made needle-microelectrode of very small dimensions (0.3x2 mm) and an electrode-tip cooling technique, based on saline solution infusion. We adjusted duration (seconds) and power (watts) of radiofrequency ablation letting them range between 5-50 seconds and 5-25 W, respectively, to obtain the greatest lesions with the least side effects. After sacrificing the animals, an accurate histological examination of the liver was made.


RESULTS
It is possible to establish beforehand the diameter of thermal liver lesion on the basis of joules of applied energy. The greatest increase of liver thermal lesion diameter (8 mm) is obtained with a 250-joule (10 W for 25 seconds) thermal energy cooling the electrode-tissue interface.


CONCLUSIONS
Experimental radiofrequency ablation in rat liver is an effective and cheap way to study its effects on healthy hepatic tissues. It might be the first step to treat experimentally caused liver tumors.
Zardi
Enrico Maria
EM
Interdisciplinary Center for Biomedical Research (CIR), Laboratory of Internal Medicine and Hepatology, Campus Bio-Medico University, Rome, Italy. e.zardi@unicampus.it
Picardi
Antonio
A
Borzomati
Domenico
D
Coppola
Roberto
R
Caricato
Marco
M
Galeotti
Tommaso
T
Valeri
Sergio
S
Bianchi
Antonella
A
Brisinda
Donatella
D
Afeltra
Antonella
A
Fenici
Riccardo
R
D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D004195:Disease Models, Animal; D004567:Electrodes, Implanted; D004867:Equipment Design; D008099:Liver / Q000601:surgery*; D008297:Male; D051381:Rats