超声微泡介导的空化效应改善急性缺血组织局部灌注的实验研究

Ultrasound Microbubble-mediated Cavitation Effect in Improvement of Local Perfusion of Acute Ischemic Tissue: An Experimental Study

目的探讨超声微泡介导的空化效应对大鼠急性缺血组织局部血流灌注的改善情况。材料与方法将 24 只雄性 SD 大鼠结扎一侧髂外动脉建立急性下肢缺血模型,然后根据不同治疗方法将大鼠分为空化组(超声+微泡)、单纯超声组及单纯微泡组,每组各 8 只,分别在造模前、造模后、治疗后进行双下肢同步超声造影灌注成像,评价大鼠缺血下肢在不同条件治疗后组织灌注的改善情况。结果治疗后,空化组大鼠缺血下肢骨骼肌血管容积(A 值)、血流速度(β值)及微血管血流量(MBF)均较空化前明显增加[A 值:(69.53±2.32)dB 比(50.82±3.48)dB,P=0.003;β值:(0.19±0.04)/s 比(0.16±0.02)/s,P=0.018;MBF:(13.08±1.97) dB/s 比(6.45±1.02) dB/s, P<0.001]。空化组缺血下肢空化后的 A 值(F=72.354, P<0.001)和 MBF(F=37.781,P<0.001)高于超声组和微泡组,但β值差异无统计学意义(F=2.941,P=0.088)。空化组正常侧组织血流灌注较空化前轻微增加,但差异无统计学意义(P>0.05)。结论超声微泡介导的空化效应可增加急性缺血组织的微循环血流灌注,从而增加辐照区域的局部血流。

Purpose To investigate the ultrasound microbubble-mediated cavitation effect on the improvement of local blood perfusion of acute ischemic tissue in rats. Materials and Methods Twenty-four male Sprague-Dawley (SD) rats were used to establish an acute hindlimb ischemia model by ligating the external iliac artery. The rats were randomly divided into three treatment groups according to different treatment methods: cavitation group (ultrasound+microbubble, n=8), single ultrasound group (n=8) and single microbubble group (n=8). Synchronous contrast ultrasound perfusion imaging for both hindlimbs were performed before modeling, after modeling and after treatment to evaluate the improvement of ischemic hindlimbs of rats through tissue perfusion after treatment under different conditions. Results After treatment, microvascular blood volume (A value), microvascular flux rate (β value) and microvascular blood flow (MBF) of ischemic hindlimbs of rats in the cavitation group were significantly increased as compared with before cavitation [A value:(69.53±2.32) dB vs.(50.82±3.48) dB, P=0.003;β value:(0.19±0.04)/s vs.(0.16±0.02)/s, P=0.018;MBF:(13.08±1.97) dB/s vs.(6.45±1.02) dB/s, P<0.001]. A value (F=72.354, P<0.001) and MBF (F=37.781, P<0.001) of the cavitation group after cavitation of ischemic hindlimbs were significantly higher than those of the ultrasound group and the microbubble group, but difference in β values was not statistically significant (F=2.941, P=0.088). Blood perfusion of normal side tissue in the cavitation group was also slightly increased as compared before cavitation, but there was no statistical difference (P>0.05). Conclusion Ultrasound microbubble-mediated cavitation effect can increase microcirculation blood perfusion of acute ischemic tissue, thus increasing the local blood flow in the irradiated area.