Experimental Study in the Size of the Zone of Coagulative Necro- sis in Radiofrequency Ablation in the Treatment of Liver Cancer

Objectives To evaluate the methods how to reduce or increase the size of the zone of coagulative necrosis during the treatment with radiofrequency ablation.Methods With the hook electrodes 25 percent、 50 percent、75 percent、fully deployed during the treatment with radiofrequency ablation;Combined use of ethanol injection before the treatment with radiofrequency ablation;Vascular inflow occlusion is performed by clamping the hepatic artery and portal vein in the porta hepatis(Pringle meaeuver) during the treatment with radiofrequency ablation;Treatment starting at 10W of power with 10W/minute advances up to 90W 、Treatment starting at 25W of power with 25W/minute advances up to 90W 、Treatment starting at 40W of power with 40W/minute advances up to 90W . After that , measure the zone of coagulative necrosis . Results Treatment With the hook electrodes 25 percent、50 percent、75 percent、fully deployed ,the diameter of the zone of coagulative necrosis was from 1.90 ±0.09 (cm)up to 2.89 ±0.10(cm)、3.37 ±0.10(cm)、 3.84 ±0.33(cm),P 0.01;Treatment combined use of ethanol injection the diameter of the zone of coagulative necrosis was from 3.84 ±0.33(cm)up to 3.99 ±0.10(cm),P 0.05;Treatment combined use of vascular inflow occlusion, the diameter of the zone of coagulative necrosis was from 3.84±0. 33(cm)up to 4.25 ±0.09(cm),P 0.05;Treatment starting at 10W、25W、40W of power, the diameter of the zone of coagulative necrosis was from 3.84 ±0.33(cm)down to 3.69 ±0.03(cm)、3.44 ±0.03 (cm),P0.05.Conclusion The size of the zone of coagulative necrosis may reduce by shrinking from the hook electrodes. Use of vascular inflow occlusion 、starting at a 1ower of power may increase the size of the zone of coagulative necrosis.Combined use of ethanol injection may or may not enhance the effectiveness.