The Experimental Study On Efficacy And Safety For CT-guided Microwave Ablation And Cryoablation For Living Rabbit Liver And VX2 Liver Cancer In Rabbit

Objective:1.To correlate area of low-density on CT images,post microwave and cryoablation,with that of actual complete necrotized area so as to establish theoretical basis for determining the appropriate ablation range.2.To study the efficacy and safety of CT guided microwave ablation and cryoablation in the treatment of rabbitVX2 liver cancer model.Methods:In part I,twenty New Zealand white rabbits were randomly divided into two groups(groupA:microwave ablation group,group B:Cryoablation immediate group)according to their weight.After anesthesia,the experimental rabbits were fixed on a self-made operating table and depilated for skin preparation and CT scanning.The ablation needle was inserted into the left lobe of the liver,and microwave ablation and cryoablation were performed respectively.After the ablation,the experimental rabbits were sacrificed and the liver was dissected for pathological examination.In part II,rabbitVX2 cancer model was established by CT guided percutaneous tumor seeding.Forty rabbits were randomly divided into four groups:A,B,C and D(group A:microwave ablation immediate,group B:microwave ablation 1 week,group C:Cryoablation immediate,group D:Cryoablation 1 week)according to theirtumor diameter.After anesthesia,the rabbits were fixed on a self-made operating table and depilated for skin preparation and CT scanning,ablation.The rabbits were sacrificed immediately and 1 week after operation.The liver was dissected for pathological examination.Result:1.The "incomplete ablation zone" post microwave ablation and cryoablation of the liver of healthy New Zealand white rabbits were 0.78±0.08cm and 0.32± 0.08cm,respectively.The difference was statistically significant(P<0.05).2.The complete ablation rates of the four groups were 55.6%,50%,100.0%,and 88.9%respectively.The difference was statistically significant(P<0.05).The residual rate of local tumorof the four groups were 44.4%,62.5%,0.0%,and 22.2%,respectively;the difference was statistically significant(P<0.05).3.There was a significant difference in the degree of vascular injury between the four groups(P<0.05).The rates of vascular damage were 77.8%,100.0%,0.00%and 11.1%respectively.The rates of complete vascular damage were 22.2%,75.0%,0.00%and 0.00%respectively.4.The quantity of anesthetics in the four groups was 12.21±0.79ml,12.30±0.77ml,10.65± 0.73ml and 10.65± 0.77ml respectively;the difference was statistically significant(P<0.05).Conclusion:1.The "incomplete ablation zone" of cryoablation is narrower than that of microwave ablation,suggesting easier control of ablation zone with cryoablation.Moreover,cryoablation could be used to perform conformal ablation.2.The complete ablation rate of VX2 liver cancer with cryoablation was higher,than that with microwave ablation.Moreover,the residual rate of local tumor with cryoablation was lower than that with microwave ablation.3.Compared with microwave ablation,cryoablation offer advantage of less damage to the large vessels,and is safer than microwave ablation in the treatment of tumor adjacent to the large vessels.4.The quantity of anesthetics,complication rate and mortality rate in cryoablation were lower than in microwave ablation,which proved that the tolerance and safety of cryoablation for VX2 liver cancer were higher than that of microwave ablation.