不同针间距及角度双极射频猪肝的热凝物形态分析

THE GEOMETRY ANALYSIS OF HEAT-LESION BY BIPOLAR RADIOFREQUENCY IN PORK LIVER USING DIFFERENT TIP SPACINGS AND TIP ANGLES

目的:通过对双极射频热凝(radiofrequency thermocoagulation,RFTC)在不同针间距及角度时所形成的热凝物进行形态分析,以期为疼痛病人进行RFTC提供参考。方法:两支20 G射频针在针间距10 mm、14 mm、18 mm、22 mm时分别以0°、30°、60°、90°、120°排列,在阶跃温度模式下,开始温度65℃、阶跃温度10℃、阶跃时间30 s、最终温度85℃、工作时间180 s对新鲜猪肝进行RFTC,总共4次85℃,180 s循环,每组重复5次。最后对热凝物形态进行分析。结果:两电极在间距10 mm、14 mm时以0°、30°、60°、90°、120°,间距18 mm时以0°、30°、60°,间距22 mm时以0°、30°形成带状热凝物。结论:针间距最大14 mm时角度不超过60°以及针间距18 mm时不超过30°的穿刺参数对临床使用RFTC具有参考意义。

Objective:To find proper electrode tip spacing and tip angles of bipolar radiofrequency thermocoagulation(RFTC)treatment.Methods:Two 20 G(150 mm cannulae lengths,10 mm tip lengths)RF cannula were arranged in the tip spacing of 10 mm,14 mm,18 mm and 22 mm respectively with 0°,30°,60°,90°and 120°on top of a slab of fresh pork liver whose top surface was flat.Temperature of the probes were raised from 65℃to 85℃at a rate of 10℃every 30 second,and held at 85℃for 180 second.85℃maintaining 180 second is one cycle.If the core temperature of the heat-lesions did not reach 50℃for 120 second during 4 cycles,these strip-lesions were considered invalid.The tests were repeated 5 times in each group.The geometry of RF heat-lesions are photographed and analyzed.Results:A continuous strip-lesion between two separated bipolar electrode tips was formed when the tip spacing was 10 mm,14 mm with 0°,30°,60°,90°and 120°,18 mm tip spacing with 0°,30°and 60°,and tip spacing is 22 mm with 0°and 30°,respectively.Conclusion:The following groups have referential value for Clinical use of RFTC:tip spacing is 14 mm with bipolar angle less than 60°,and 18 mm not exceed 30°.