非限制性外支架对兔移植静脉细胞增殖的影响

The effect of non-restrictive external stent on cell proliferation in rabbit vein grafts

目的探讨非限制性外支架对兔移植静脉细胞增殖的影响及其防治移植静脉内膜增生的效果。方法新西兰白兔36只，随机均分为支架组（S组）和对照组（NS组），每只动物均施行颈外静脉颈总动脉移植术，S组在移植静脉外套以非限制性外支架，NS组无外支架。分别于术后1、2、4周取材进行观察，组织切片进行HE染色及α平滑肌肌动蛋白（α-SMA）、PCNA免疫组化染色，光镜下观察移植静脉的病理改变，计算移植静脉内膜、中膜、外膜的PCNA增殖指数。结果HE染色观察见术后1～4周S组和NS组内膜、中膜均逐渐增生，但前者的增生程度均轻于后者。α-SMA免疫组化染色见1周时两组中膜全部细胞均染色阳性，但内膜阳性细胞数相对较少；2～4周S组和NS组内膜均增厚，除管腔表面的内皮细胞外，其余细胞几乎全部为染色阳性的细胞，但S组内膜增厚程度明显轻于NS组。两组内膜和外膜的PCNA阳性率均在2周时达高峰，在2周及4周时，S组内膜阳性率明显低于NS组，而外膜阳性率明显高于NS组（P〈0．05）；两组中膜的PCNA阳性率在1周时达高峰，且1～4周时S组阳性率均低于NS组（P〈0．05）。结论非限制性外支架可抑制移植静脉早期细胞增殖，抑制内膜和中膜增生。

Objective To investigate the effect of non-restrictive external stent on both cell proliferation of rabbit vein grafts and pre vention from hyperplasia of the graft＇s neointirua. Methods 36 New Zealand white rabbits were randomly divided into two groups, each animal was subjected to a reversed autologous venous graft between external jugular vein and common carotid artery. In stenting group （group S）, the vein grafts were surrounded by a 6 mm in diameter non-restrictive stent, and in non-stenting group （group NS）, there is no stent to support the vein grafts. The grafts were harvested 1 week （1W）, 2 weeks （2W） and 4 weeks （4W） after surgery, respectively. The sections were stained with hernatoxylin and eosin stain, α-smooth muscle actin （α-SMA） and proliferating cell nuclear antigen （PCNA） immunocytochemistry stain. PCNA index was calculated in intirna, media and adventitia, respectively. Results （1） HE staining： From 1W to 4W, the hyperplasia of intirna and media appeared gradually in both group S and group NS, nevertheless such hyperplasia in group S was lessintense than in group NS. （2） α-SMA staining： Almost all cells in media were positive, but few cells were positive in intirna of both groups at lW; the thickness of intirna of both groups increased gradually, and almost all cells except endothdial cells were positive in intirna in both groups, though the thickness of intirna of group S was smaller than in group NS at 2W and 4W. （3） PCNA index： the index of intirna in both two groups peaked at 2W, and the index of intirna in group S was less than in group NS at 2W and 4W, P〈0. 05; the index of media in both groups peaked at 1W, and the index of media in group S was less than in group NS from lW to 4W, P〈0. 05 ; the index of adventitia in both groups peaked at 2W, and the index of adventitia in group S was greater than in group NS at 2W and 4W, P〈0. 05. Conclusion Non-restrictive external stenting inhibits the cell proliferation of the vein grafts, and inhibits the hyperplasia of the intirna and media.