灰阶超声造影在肝外伤微波凝固治疗的实验研究

Gray-scale contrast-enhanced ultrasound in microwave tissue coagulation therapy for hepatic trauma: experimental study

目的探讨灰阶超声造影在肝外伤微波凝固治疗中的应用价值。方法开腹状态下建立猪II级肝外伤伴活动性出血模型32处,微波凝固治疗功率分别采用70W和80W,时间5min。分别于治疗前、后应用常规超声及灰阶超声造影观察肝内损伤区的变化。结果常规超声难以显示肝外伤后所致的活动性出血。灰阶超声造影由于能清晰显示损伤区内的活动性出血,可实时引导将微波电极准确放置在肝内活动性出血部位。微波凝固治疗后,70W、80W两组治疗区呈长径分别为[(4.61±0.39)cm,(4.71±0.57)cm](t=-0.48,P>0.05)、短径分别为[(3.03±0.60)cm,(2.77±0.41)cm](t=1.14,P>0.05)的近似椭圆形无回声区,其中心部除针道呈极亮的强回声外均未见增强,呈负性显影;而56.2%(9/16)的70W治疗区和37.5%(6/16)的80W治疗区周边部可见少许线状增强。病理学证实,微波治疗区中心部汇管区的血管呈不同程度的退变坏死,肝细胞退变坏死,而周边部以肝细胞退变坏死为主要表现,血管坏死不明显。结论灰阶超声造影可用于实时引导微波电极的置入和术后疗效的判断,在肝外伤微波凝固治疗中具有一定的应用价值。

Objective To evaluate the value of gray-scale contrast-enhanced ultrasound （CEUS） in the therapy of microwave tissue coagulation （MTC） for hepatic trauma. Methods Thirty-two hepatic trauma of grade II with active hemorrhage were created in 7 porcine livers. The power of MTC was 70W and 80W respectively. Conventional ultrasound and CEUS were performed before and after MTC. Results Conventional ultrasound was not able to detect the specific location of the active hemorrhage in any of the livers evaluated before MTC. After injecting contrast agent, all bleeding sites could be detected by CEUS which could be used to guide the inserting of microwave electrode successfully. After MTC, CEUS showed that the sizes of 70 W and 80 W groups were （[4.61±0.39] cm, [4.71±0.57] cm） （t=0.48, P〉0.05） in length and （[3.03±0.60] cm, [2.77±0.41] cm） （t=1.14, P〉0.05） in width, respectively. The centre area of the therapeutic region was not enhaned in both groups which was the results of necrotic hepatic vessels and liver cells proved by pathology. A few enhanced regions could be seen in the periphery area in 56.2% of 70 W and in 37.5% of 80 W therapeutic regions. Conclusion CEUS is useful in guiding the inserting of microwave electrode and could be used to assess the curative effect of MTC for hepatic trauma.