title: Radiofrequency ablation of hepatic tissue: a new experimental animal model.
abstract: 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.
authors.affiliation: Interdisciplinary Center for Biomedical Research (CIR), Laboratory of Internal Medicine and Hepatology, Campus Bio-Medico University, Rome, Italy. e.zardi@unicampus.it
authors.forename: Enrico Maria
authors.initials: EM
authors.lastname: Zardi
authors.forename: Antonio
authors.initials: A
authors.lastname: Picardi
authors.forename: Domenico
authors.initials: D
authors.lastname: Borzomati
authors.forename: Roberto
authors.initials: R
authors.lastname: Coppola
authors.forename: Marco
authors.initials: M
authors.lastname: Caricato
authors.forename: Tommaso
authors.initials: T
authors.lastname: Galeotti
authors.forename: Sergio
authors.initials: S
authors.lastname: Valeri
authors.forename: Antonella
authors.initials: A
authors.lastname: Bianchi
authors.forename: Donatella
authors.initials: D
authors.lastname: Brisinda
authors.forename: Antonella
authors.initials: A
authors.lastname: Afeltra
authors.forename: Riccardo
authors.initials: R
authors.lastname: Fenici
mesh_terms: 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