| Objective1.To investigate dynamic changes of ablative data obtained by microwaveablation alone in ex vivo bovine livers, and to explore the correlation betweenthe ablation data and time;2.To detect whether the ablation zone could be effected by preinjectedabsolute ethanol in situ before microwave ablation in ex vivo bovine livers.Materials and methodsA2450MHz microwave ablation system with water-circulation-cooling wasused in this study. The experimental study was performed in freshly slaughteredtwenty ex vivo bovine livers purchased gradedly, which were randomly dividedinto alone microwave ablation group (alone group) and microwave combinedabsolute ethanol group (combination group). All the ablations were performed inhepatic tissue away from large vessels at a set power of50W.①There wereeight subgroups (1min,2min,3min,4min,5min,7min,8min,10min) in alonegroup and each time point was selected three sites for ablation(n=3), with atotal of24ablations performed. Observe shape of all the ablations and measurethe longitudinal diameter (LD), transverse diameter (TD) and calculat TD/LD(shape index ratio) and Volume; draw dynamic plot about ablation data-timeand explore their dynamic changes according to all the data obtained in thealone group.②There are six subgroups (2.5ml/4min,5ml/4min,5ml/5min,7.5ml/5min,7.5ml/8min,10ml/8min) in combination group and each subgroup wasselected three sites for ablation as well (n=3), with a total of18ablationsperformed. Each subgroup, which was preinjected absolute ethanol into thetargeted hepatic tissue before microwave ablation, was used to compare with alone group accordingly. After ablation, the ablation diameter, shape index andvolume were analyzed and compared.Results1.The ablation LD, TD and Volume, which were performed under the fixedpower of50W in the time range of1min～10min, were all associated with timein a non-linear correlation (the value of R is0.9678,0.9791,0.9814,respectively): Both of LD and TD were associated with time in a logarithmiccorrelation to a high degree; Volume and time were in a parabolic correlation toa high degree; The amplification of ablation data is more conspicuous in theprophase than that in advanced phase, and the ablation data reached relativeplateau in7min; The amplification of TD is more conspicuous than LD with theprolongation of time.2.The combination groups get larger extent(LD, TD andVolume) than thatin the alone group; And the difference was statistically significant reveals thatthere is a tendency of expanding in ablation extent (LD, Volume) with the doseof absolute ethanol increases.Conclusions1.The ablation LD, TD and volume are all associated with time in anon-linear correlation to a high degree. The prolongation of time offers more tothe amplification of TD than LD. The amplification of ablation data is moreconspicuous in the prophase than that in advanced phase, and the ablation datareached relative plateau in7min;2.For ex-vivo bovine liver, the extent of ablation zone can be increased bypreinjected absolute ethanol in situ before microwave ablation within a certaintime and there is a tendency of expanding in LD and Volume with the dose ofabsolute ethanol increase. |
