低驻波比微波天线凝固效能的对比观察

Comparative observation of coagulation efficiency with different standing wave ratio microwave antenna

目的比较两组不同驻波比(SWR)微波天线在大功率/长时间条件下离体肝组织凝固效能。方法应用SWR分别为1.5(实验组)和2.5(对照组)的微波天线各20根,天线输入功率80W/20min,对新鲜离体牛肝脏进行消融,并对两组凝固灶的范围、形态及天线完好性进行比较。结果实验组凝固灶短径(52.8±6.4)mm、长径(71.5±6.9)mm,球形指数(短径/长径)0.741±0.067;对照组凝固灶短径(48.1±4.6)mm、长径(65.1±4.9)mm,球形指数0.738±0.057。两组凝固灶的短径和长径差异有统计学意义(P=0.016、0.004),但球形指数差异无统计学意义(P=0.875)。实验组天线完好无损,对照组3根天线损毁。结论低SWR经皮微波天线在大功率/长时间条件下,对离体肝组织凝固效能优越,安全性高。

Objective To compare coagulation efficiency in isolated liver tissue between different standing wave ratio （SWR） microwave antennas under the condition of high power and long time. Methods Fresh liver of bovine in vitro were ablated with 20 low SWR （1.5） microwave antennas （experimental group） and 20 high SWR （2. 5） microwave antennas （control group）. Antenna microwave energy was applied in one session with 80 W for 20 min. After ablations, the shape and diameter of coagulated region, the integrity of the antennas were observed and compared. Results The average short and long diameters of the coagulated region in the experiment group was （52.8±6.4）mm and （71.5±6.9）mm, while in the control group was （48.1 ±4.6）mm and （65.1±4.9） mm, respectively. Spherical index of coagulated region of the experimental group and the control group was 0. 741±0. 067 and 0. 738±0. 057, respectively. Both short and long diameters of the coagulated region in the experimental group were significantly larger than those of the control group （P= 0. 016, 0. 004）. There was no significant difference in spherical index between the two groups （P=0. 875）. Finally, 3 antennas of the control group were damaged, while those of the experiment group remained intact. Conclusion Adopting novel low SWR microwave antennas could expand the coagulated region in isolated liver tissue under the condition of high power and long time, which may help to improve local efficacy.