Biliary lesions during radiofrequency ablation in liver. Study on the pig

BACKGROUND: Radiofrequency (RF) is a method of in situ destruction of liver tumor. Biliary complications are bile ducts stenosis or biliary abcess. The aim of this work was to study consequences of liver RF on bile ducts. METHODS: A porcine model of biliary lesions was created using radiofrequency ablation liver. Twenty-two pigs were used for the study. The RF RITA 1500 generator (RITA Medical Systems, Mountain View, Calif., USA) was used for all experiments. The needle was positioned under sonographic control in liver parenchyma beside bile ducts. Two lesions were performed in left liver. Four groups of 5 pigs were treated. The pigs were sacrificed 1 or 3 weeks after the procedure. Pringle maneuver was utilized in half of the RF procedures. An ex vivo cholangiogram was obtained by direct injection into the main bile duct. Samples of RF lesions of liver parenchyma near and at a distance from the RF lesions were taken for pathological studies. RESULTS: Radiological lesions were biliary stenosis, with or without upstream bile duct dilatation, or complete interruption of the bile duct, or extravasation of the radiological contrast agent. Histological lesions of bile ducts were observed near RF lesions and at distance of the RF lesions when a Pringle maneuver was used or when the liver was removed after 3 weeks. CONCLUSIONS: RF ablation in contact of the intrahepatic bile duct induced biliary lesions. Therefore, it is required to stay away from the bile duct or to protect it when performing RF ablation.