3种血管替代物植入人体后的变化及比较分析

Histological changes and comparisons of three great vessel substitutes after human implantation

目的:了解临床上3种常用血管替代物人体内移植后的变化。方法:临床获取因治疗需要而取出的先天性心脏病患儿早期植入的Gore-Tex管道、牛颈静脉管道和同种带瓣管道标本,通过对大体标本观察,组织学切片HE染色、Masson染色、Verhoeff弹性纤维染色以及特异性细胞标记物(α-SMA、calponin、VE-cadherin)免疫组织化学染色,评价移植物植入人体后的变化。结果:Gore-Tex管道移植后原管道未降解,管道壁中无细胞长入,管腔内形成假膜,其中假膜富含胶原纤维,无弹性纤维,散在α-SMA+细胞和calponin+细胞。牛颈静脉管道移植后,原管道未降解,管道壁中无细胞长入,管腔内可见假膜,假膜较厚,富含胶原纤维,但存在特殊排列的弹性纤维,弹性纤维所在区域聚集α-SMA+细胞和calponin+细胞。同种带瓣管道移植后,管道近乎全层钙化,仅残留浅薄的内膜,内膜表面光滑,无假膜形成,可见VE-cadherin+内皮细胞层及残存的平滑肌细胞。结论:Gore-Tex管道和牛颈静脉管道难以降解,且不具备生长性,远期易出现管道狭窄;同种带瓣管道移植后无假膜形成,但易出现钙化,限制了管道的使用寿命。

Objective：To investigate the changes of three commonly used blood vessel substitutes in vivo after implantation. Methods：Gore-Tex conduit,bovine jugular vein conduit and valved homograft conduit were obtained from patients who had received graft implantation in their early ages.The conduit grafts were processed for gross observation,HE stain, Masson stain,Verhoeff elastin stain and immunohistochemistry stains on specific cell markers,includingα-SMA,calponin and VE-cadherin,for investigations on the histological changes after human implantation. Results：After human implantation,the Gore-Tex conduit didn′t degrade,and cell ingrowth was not observed.However,neointima formed inside the lumen,which included much collagen and scatteredα-SMA＋and calponin＋cells,but no elastin fiber.After bovine jugular vein conduit was implanted,the graft didn′t degrade with no cell ingrowing into the wall,but neointima formation was observed.The neointima formed inside the bovine jugular vein was thicker than that inside the Gore-Tex conduit,and was with abundant collagen and particularly arranged elastin fiber.Histological sections revealed a cluster ofα-SMA＋and calponin＋cells in the area where elastin fiber was observed.After valved homograft conduit was implanted,a nearly full-layer calcification leaving only a thin layer of intima was observed,however,no neointima formed and the luminal surface was smooth.VE-cadherin＋endothelial cells covered the luminal surface and was beneath the residual smooth muscle cell.Conclusions：Gore-Tex conduit and bovine jugular vein conduit are incapable of degrading and growing after implantation,which is easy to result in restenosis of the conduit in the late follow-up.Valved homograft conduit is the only vessel substitute with no neointima formation.Calcification is the main drawback of valved homograft conduit,which restrains the lifespan of the graft.