真圆微波消融与传统微波消融效果对比的离体实验研究

Comparison of microwave thermosphere ablation and conventional microwave ablation in ex vivo bovine livers

目的比较真圆微波消融(MTA)技术与传统微波消融(MWA)技术的消融效果及受热沉效应影响的程度。方法采用新鲜牛肝,分为MTA组和MWA组,分别建立无血管模型和有血管模型。无血管模型(48例)采用相同功率时间设置,分别为80W12min、90W10min和100W10min,比较两组消融灶长径(Dl)、短径(Ds1、Ds2)、圆度系数(R)以及距消融针1cm处温度升至60℃所需时间(t)。有血管模型(144例)设置不同血管内径(3mm、5mm、10mm)和血流速度(15cm/s、20cm/s、30cm/s),比较两组消融灶横截面最大半径(Rmax)、面积(Sz)、面积变化率(Sdiff),并监测血管壁处温度变化。结果无血管模型中,相同功率时间下,MTA组Dl小于MWA组(P<0.01),MTA组Ds1、Ds2与MWA组比较,差异无统计学意义(P>0.05),且MTA组消融灶更接近球形(R更接近1,P<0.01),MTA组t大于MWA组(P<0.01)。有血管模型中,MTA组Sdiff不受血管内径及血流速度影响,各组间比较差异无统计学意义(P>0.05),MWA组Sdiff受血管内径影响较为明显(P<0.01),不同血流速度组间差异无统计学意义(P>0.05)。当血管内径为10mm时,MTA组Sdiff小于MWA组(P<0.05),血管内径为3mm、5mm时,两组间差异无统计学意义(P>0.05)。结论相同功率时间下,与MWA相比,MTA可以产生大小相当、形态规则、更接近球形的消融灶,且受热沉效应的影响更小。

Objective To compare the effectiveness of microwave thermosphere ablation(MTA) and traditional microwave ablation(MWA) in ex vivo bovine livers, and to compare the degree of the heat sink effect in them. Methods The non-vessel model and vessel model were established using fresh bovine livers. In non-vessel model(n=48), the same power-time settings were used in both MTA group and MWA group, which were 80 W 12 min, 90 W 10 min and 100 W 10 min, respectively. Long-axis diameter(Dl), short-axis diameter(Ds1, Ds2), roundness index(R) and the time of temperature rising to 60℃ at place of 10 mm from the needle were measured.In vessel model(n=144), different vessel diameters(3 mm, 5 mm, 10 mm) and flow rates (15 cm/s, 20 cm/s, 30 cm/s) were setted. The maximum radius(Rmax), total area of ablation zone(Sz), and the area difference (Sdiff) were analyzed, the temperatures adjacent to the vessel were monitored simultaneously. Results In non-vessel model, with the same power and time settings, the Dl of MTA group was significantly smaller than MWA group (P<0.01), however, there was no significant difference of Ds1 and Ds2 between the two groups(P>0.05). And MTA group created more spherical ablation zones, since the R of MTA group were more close to 1 (P<0.01). In MTA group, the time of temperature rising to 60 ℃ at place of 10 mm from the needle was slower than MWA group (P<0.01). In vessel model, the Sdiff of MTA group were hardly affected by the vessel diameters and flow rates(P>0.05), and there was also no statistical significance among different flow rates(P>0.05) in MWA group, but the Sdiff of MWA group was significantly affected by the vessel diameters(P<0.01). And the Sdiff of MTA group was significantly smaller than MWA group when the vessel diameter was 10 mm(P<0.05), while there was no statistical significance between the two groups when the vessel diameter was 3 mm or 5 mm(P>0.05). Conclusions Compared to MWA, MTA can produce sizable, regular and more spherical ablation lesions with the same power and time, meanwhile, it is less affected by the heat sink effect.