四氧化三铁微粒与碘化油混悬液栓塞兔肾动脉的实验研究

Transcather rabbit renal arterial embolization using suspension from magnetic microspheres with lipiodol: experimental study

目的探讨四氧化三铁(Fe3O4)微粒与碘化油(Lp)混悬液(suspension from magnetic microspheres with lipiodol, S-Fe3O4-Lp)对兔肾动脉的栓塞和导向作用机制.方法测定工业工艺制备粒径为50～250 μm 5种规格的Fe3O4微粒在Lp中的沉降时间、速度;实验组用粒径250 μm的S-Fe3O4-Lp对右肾动脉栓塞,对照组用Lp栓塞.两组于术后不同时间比较栓塞效果、观察血生化和病理学改变.结果五种粒度的Fe3O4微粒能在一定时间范围内悬浮于Lp中;栓塞效果实验组优于对照组;实验组栓塞部位Fe3O4微粒与Lp存留存在明显正相关关系(P＜0.005,r=0.76).结论粒径为250 μm的S-Fe3O4-Lp对兔肾动脉栓塞效果好,无明显毒副反应;栓塞过程中Fe3O4微粒与Lp具有同步、同向性,是S-Fe3O4-Lp发挥导向性栓塞的基础.

Objective To investigate the embolic effectiveness and mechanism of targeting embolization of the suspension from magnetic microspheres with lipiodol by transcather renal arterial embolization of rabbit's kidneys. Methods The suspending ability of five size of magnetic microsphere which average diameter was 50, 100, 150, 200, and 250 μm were evaluated by test of their falling speed and time in lipiodol. Fifteen healthy New Zealand rabbits were divided into two groups at random, 10 for the experimental group embolized with the suspension of 250 μm magnetic microspheres and lipiodol, 5 for the control group only embolized with lipiodol. Two group's experimental results were based on abdominal plain film, renal arteriography and histopathologic study of the embolized and unembolized kidneys, heart, lung, liver after sacrifice 3 days, 1, 2, 4, 6, or 8 week after embolization. Results Five size of magnetic microsphere not only can be suspended in lipiodol but keep suspending situation for a relative long time. The average time when they fall 10% in lipiodol were 120, 85, 60, 45, 30 min and the average falling speeds were 0.32, 0.45, 0.87, 0.91, 1.20 cm/h respectively ( P <0.001). The pathological and renal arteriography showed embolic effectiveness in the experimental group is superior to the control group. The suspension produced more necrosis than did lipiodol. 250 μm magnetic microspheres and lipiodol showed significant positive correlation ( P <0.005, r =0.76) in occluded arteries including renal glomeruli and intelober artery. Changes in the density of embolized kidneys by abdominal plain film showed a significant difference after 2, 4, 6 weeks between the experimental group and the control group ( P 2 <0.05, P 3 <0.05). No significant changes were observed in 1 week ( P 1 >0.05). The serum iron and liver, renal function manifested no significant difference after embolization with the suspension of 250 μm magnetic microspheres and lipiodol ( P >0.05). Conclusion During the whole course of embolization, 250 μm magnetic microspheres can keep suspending in lipiodol all the time and move together into the embolized small arteries in the end.