Laparoscopic radiofrequency ablation of the liver in proximity to major vasculature: Effect of the Pringle maneuver

Background and Objectives: The Pringle maneuver has been shown to increase ablation size during radiofrequency ablation (RFA). Efficacy of laparoscopic Pringle in proximity to major vasculature has not been well described. Laparoscopic RFA was performed in proximity to major hepatic vessels to examine effects of the Pringle on ablation size and vascular damage. Methods: Laparoscopic RFA was performed in 10 pigs. Each underwent ablation of a peripheral site, and sites adjacent to the portal and hepatic veins. Ultrasound was used to position the RFA adjacent to vascular structures. US flow characteristics verified occlusion of blood flow. Five pigs underwent laparoscopic RFA with Pringle and five underwent laparoscopic RFA alone. Animals were then sacrificed for gross and microscopic evaluation. Results: Peripheral, hepatic, and portal vein ablations showed no significant differences in volume between non-Pringle and Pringle lesions, though the median ablation volume for the peripheral site in the Pringle group was approximately twice that of the non-Pringle group. Pringle group overall median time to target temperature was significantly shorter (P = 0.047). Histologic examination revealed no evidence of endothelial damage or thermal-induced intravascular thrombosis of the hepatic or portal veins. Conclusions: Laparoscopic RFA with Pringle in proximity to major vascular structures does not significantly increase ablation size, or cause acute vascular damage. Further studies are necessary to determine the utility of the Pringle in proximity to major intrahepatic blood vessels.