经皮微波凝固疗法肝组织热场分布的实验研究

An experimental study on the thermal distribution of percutaneous microwave coagulation in liver

目的 :探讨微波凝固肝组织局部热场分布规律。方法 :采用单微波电极对离体新鲜猪肝及活体兔、猪肝进行微波凝固 ,观察热场中凝固区最大短轴上序列点温度随时间的动态变化 ,同时观察凝固区边缘、移性区各部位的温度。结果 :某一时刻短轴上各点温度 (y)和其与中心的距离 (x)符合函数x2 =-2py+b ;随x递增和 /或功率递减 ,各测温点的温度上升速度渐次减慢 ,并相继达到渐次减低的饱和温度 ;远隔组织在中、后期温升相对较快 ;离体凝固的中心温度恒定为 1 0 5℃ ,而活体凝固则因有、无供血而异 ,凝固功率 4 5W时其温度分别为83℃、92℃ ,血流对微波凝固范围、形态有显著影响 ;凝固区边缘、移行区温度较恒定 ,分别为 5 0℃～ 5 2 .5℃、4 8℃～ 5 0℃ ;6.36mm天线的热场内组织凝固形态最佳。结论 :在人体组织中微波的热场分布是微波物理特性、微波天线性能、组织热传导性、血供等因素的综合作用 ;合适的天线长度、适当地增加凝固功率、延长凝固时间、中断组织供血有利于显著扩大凝固区。

Objective:To disclose the thermal distribution way of percutaneous microwave coagulation therapy(PMCT)in liver in order to find ways to enlarge its MC space.Methods:Fresh pig livers in vitro,rabbit and pig livers in vivo were coagulated with single electrode of a microwave coagulator.Draw curves of temperatures at points in sequence on the short axis at respective moments.Draw respective curves of dynamic temperature of every above mentioned points.Results:The temperature(y)and the distance(x)to the center complied to the formula:x 2=-2py+b.The temperature ascending speed slowed down gradually with the distance increase or the power decrease,and it led to certain but lower peak temperatures finally.The core temperatures in vitro were 105℃ steadily, while it varied in vivo when blood supply existed or not,e.g,it's 83℃ or 92℃ respectively when the power was 45 W.Blood flow exerted influence both on MC volume and shape.The temperature in remote area went up faster in mid and later stage.The temperature remained stable in vitro or in vivo at the edge of the coagulation section and the transition belt,i.e. 50℃ 52.5℃?48℃ 50℃ respectively.36 mm antenna led to the best MC shape.Conclusion:The thermal distribution of microwave coagulation was determined by multi factors:its own physical properties,the length of the antenna,the thermal conduction of tissues and blood supply.To coagulate ischemic tissue with antenna of 36 mm in length,appropriate larger cogulation power,longer time could obtain a bigger and better coagulation space. Key words microcoagulation therapy,percutaneous;liver;field, thermal;rabbits;pigs n adult Conclusions The complication rate of the soft tissue expansion in pediatric was higher than that in adult, and the highest in the exposed expanders and the implanting site of faces and necks.In addition,the complication rate was higher among the children who didn't reside during inflation than those who did. It is sure that observation and nurse carefully during inflation and follow by the principle of plastic surgery strictly during operation are effective methods against the complications