32P液体球囊血管内照射预防血管成形术后再狭窄

目的 探讨^32P液体球囊血管内近距离照射治疗对防止血管成形术后再狭窄的量效关系及其抑制再狭窄发生的可能机制。方法 27只雌性大白兔据动脉球囊扩张损伤后，实验组(18只)分别给予3、9、18和36Gy^32P液体球囊行内照射治疗，对照组(9只)灌注生理盐水。术后于不同时间点取材，行HE染色、增殖细胞核抗原(PCNA)免疫组织化学染色以及电镜观察血管组织形态学的改变，用计算机图像分析法测量管腔面积和内膜面积。结果 对照组血管内膜明显增生，管腔变狭窄。18Gy组血管壁平滑肌细胞增殖明显受抑，细胞凋亡增加，管腔面积无明显丢失；36GY组血栓形成明显；3和9Gy组均未观察到明显的生物效应。结论 ^32P液体球囊血管内照射可防止血管成形术后再狭窄发生，其机制可能为抑制血管壁平滑肌细胞增殖，促进其凋亡及改善血管重塑形。

Experimental study of endovascular irradiation preventing restenosis after angioplasty

Objective To observe the dose effect relation of endovascular brachytherapy using radioactive liquid filled balloon and restenosis after angioplasty and to investigate the possible mechanism of irradiation therapy preventing restenosis. Methods After balloon dilating injury of rabbit iliac arteries, the 4 experimental groups were administered 32 P brachytherapy, the absorbed doses were 3, 9, 18 and 36 Gy, respectively. For the control groups the balloons were filled with normal saline. Pathological sections of iliac arteries at different end points were studied by means of HE staining, proliferating cell nuclear antigen (PCNA) immunohistochemical staining and electron microscopy. We also measured the lumen areas and neointima areas by computer analysis of photomicrographs. Results Strong neointimal proliferation and strait lumen were observed in the control group. In 18 Gy group, the proliferation of smooth muscle cells was obviously suppressed, cell apoptosis increased, and the lumen area did not decrease. Arterial thrombosis occurred in 36 Gy group. There weren't obvious changes in 3 and 9 Gy groups. Conclusions Endovascular brachytherapy using 32 P filled balloon catheter system can prevent restenosis after angioplasty. The mechanism might be the inhibition on the proliferation of smooth muscle cells, increase in apoptosis and improvement of vascular remodeling.