经直肠微波消融犬前列腺组织的实验研究

Ultrasound-guided transrectal microwave ablation of the prostate in dogs

目的:探讨超声引导下经直肠微波消融前列腺组织使其体积减小的可行性及安全性。方法:犬麻醉后在超声引导下经直肠对实验犬前列腺的左右两侧叶分别进行微波消融,微波输出能量30 W,作用时间120 s,消融后当天处死动物取出前列腺及周围组织标本,观察消融灶的形态及前列腺周围组织结构有无损伤、测量消融灶体积,最后标本送病理检查。结果:在实验犬前列腺左右两侧叶成功进行了12个点微波消融灶,消融过程中超声图像显示消融区为强回声,范围逐渐扩大,最后热消融区表现为不均质强回声,边界清楚,形态欠规则。大体标本观察:直肠壁穿刺点粘膜下可见少量淤血,局部无热损伤改变,尿道及膀胱壁未见明显热损伤,消融灶呈椭圆形,边界清楚,实测体积为(0.94±0.30)cm3。结论:超声引导下经直肠微波消融前列腺可使局部组织发生凝固性坏死,对前列腺周围重要结构无明显热损伤。二维超声可以实时显示消融区的范围、监控消融过程。

Objective： To investigate the feasibility and safety of ultrasound-guided transrectal microwave ablation in reducing the prostate volume.Methods： Ultrasound-guided transrectal microwave ablation of both sides of the prostate was conducted on experimental dogs with the output volume of 30W for 120 seconds.The dogs were sacrificed on the very day of the ablation,and the prostate and its surrounding tissues were excised for observation of the thermal lesions and pathological examination.Results： A total of 12 thermal lesions were achieved on the two sides of the prostate.The ultrasonogram manifested dense echo and increasing extent in the ablated area,and then an irregular heterogeneous echogenic area and clearly differentiated margin.Pathological examination of the gross specimen showed a little stagnant blood under the rectal mucous,the urethra and bladder not injured,and the thermal lesions elliptical,clearly margined and with the mean size of（0.94±0.30） cm3.Conclusion： Ultrasound-guided transrectal microwave ablation of the prostate can effectively cause coagulative necrosis of the local tissue without inflicting thermal injury upon the surrounding tissues.Conventional grayscale ultrasound can give a real-time display of the extent of thermal lesion and the whole process of the ablation.