Effect of vascular occlusion on radiofrequency ablation of the liver: results in a porcine model.

OBJECTIVE. This study determined the effect of vascular occlusion on radiofrequency lesion shape, volume, and temperature in a porcine liver model.SUBJECTS AND METHODS. Radiofrequency lesions (n = 33) were created in the livers of six domestic pigs in vivo using a multiprong radiofrequency electrode. Lesions were randomly assigned to one of four vascular occlusion groups: portal vein, hepatic artery, Pringle maneuver (both hepatic artery and portal vein), or no occlusion. Radiofrequency parameters were time, 7 min; power, 50 W; and target temperature, 100°C. Temperatures were measured 5, 10, and 15 mm from the electrode. After the animals were sacrificed, the lesions were excised. Lesion volume, diameter, and shape; maximum temperature; and time exposed to lethal temperatures (42-60°C) were determined.RESULTS. Lesion volume was greatest with the Pringle maneuver lesions (12.6 ± 4.8 cm3), followed by occlusion of the portal vein (8.6 ± 3.8 cm3), occlusion of the hepatic artery (7.6 ± 2.9 cm3), and no occlu...