超声引导下扩大微波消融活体犬脑组织安全性和可行性的实验研究

目的 探讨扩大超声引导下实验家犬脑组织微波消融灶的可行性和安全性,为超声引导微波消融脑肿瘤的临床应用提供实验依据.方法 以不同微波功率(20 W、30 W、40 W)及不同消融时间(60 s、90 s、120 s、150 s、180 s)随机作用于20只家犬脑组织,术中监测颅内压并应用电生理监测仪监测脑电图变化,术后1 h超声探测消融灶声像图变化,术后4~5 h取实验犬脑组织观察消融灶大体及镜下病理变化并测量水肿带宽度.应用多元线性回归分析消融灶长径、宽径与微波输出功率及时间的关系,并建立回归方程.结果 (1)20只实验家犬中10只完成颅内压监测,其中8只从消融开始至消融结束30 min内颅内压未见明显变化;2只颅内压显著升高.(2)脑电图监测结果显示消融灶波形平直,平均波幅(5.7±1.61)μV,消融灶旁开0.3 cm处以弥散性δ和θ波为主,消融灶旁开0.6 cm处以δ波为主.(3)病理大体标本显示微波消融灶呈椭圆形,随着消融时间及功率增加,消融灶长径(L)及宽径(W)均呈线性增加,消融灶长径、宽径与微波输出功率及时间建立的多元线性回归方程分别为L＝0.038P+0.009T,W＝0.012P+0.007T.结论 实验研究结果初步表明,在20 W×60 s~40 W×150 s时间功率组合范围内,消融灶随微波输出功率及消融时间增加而消融范围增大,在此时间功率组合范围内增加脑组织微波消融范围安全、可行.

Ultrasonography Canidae Microwave ablation Brain tissue

Objective To explore the safety and feasibility of enlarging the area of coagulation by microwave ablation（MA）in brain tissues,and to provide experimental evidences for clinical application.Methods Twenty canine brain tissues were treated with different microwave output power and ablation duration.During the operation,the intracranial pressure and the change of electroencephalogram were monitored.Ultrasonography was performed within 1 hour after MA.4-5 hours after MA,the animals were executed.The morphologic and microscopic changes of microwave ablated tissues were observed,and the diameter of edema areas was measured.Results The morphology of the ablation lesions were oval,the length and width were bigger as the microwave output power and ablation duration increased.The length（L）and width（W）of microwave ablation were linearly correlated with microwave output power（P）and ablation duration（T）.The regressive equation was L=0.038P＋0.009T,W=0.012P＋0.007T respectively.The intracranial pressure was documented in ten dogs,no change was detected in 8 dogs,apparently change was detected in 2 dogs.Electroencephalogram showed that the amplitude of the ablation lesion was（5.7±1.61）μV.There were mainly δ and θ waves at 0.3 cm around the ablation lesion boundary and δ wave at 0.6 cm around the ablation lesion boundary.Conclusions In given range,the size of ablated lesions enlarged with the increase of output power and ablation duration.The preliminary results show that it is safe and feasible to enlarge the ablation lesion of brain tissue.