小口径生物型人工血管移植后的血管内皮再生

背景:经过生物化改造的人工血管特性更接近人体血管,移植后自体化程度也较高,但人工血管的内皮再生是解决血管长期通畅的关键。目的:观察新型小口径生物型人造血管移植后不同时期移植材料的组织相容性及移植血管壁内膜再生的组织病理学变化。方法:建立犬颈总动脉-人造血管端端连续缝合的动物模型。结果与结论:①光镜:移植后12周于吻合口处见新内膜表面有不连续的内皮细胞生长;移植后6个月通畅的整段管腔内面均可见内皮细胞生长;移植后1.5年管腔通畅,部分内膜组织呈慢性炎症表现。②电镜:移植后12周新生血管内皮细胞排列规则,从吻合口向移植血管中段爬行;移植后6个月内皮细胞从吻合口向移植血管中段爬行,移植血管中段呈跳跃式片状生长的内皮细胞群落,细胞排列更致密,形态更接近成熟血管内皮细胞;移植后1.5年整段血管内壁均有致密内皮细胞覆盖,部分内膜组织呈慢性炎症表现。说明新型小口径生物型人造血管新生内皮形成早,血管内膜重构能力强,生物相容和稳定性好。

Vascular endothelial regeneration after small-diameter bioartificial vascular graft

BACKGROUND:Characteristics of vascular prostheses are similar to the natural vessels and it has high histocompatibility after transplantation. But endothelial regeneration is the key for vascular prosthesis unblocked eternally. OBJECTIVE:To investigate the histocompatibility of a novel small-diameter bioartificial vascular graft at different periods postoperatively and the histopathologic changes following intimal regeneration of the vessel wall. METHODS:A dog model of artificial vascular grafts implanted end-to-end by a continuous suture in the common carotid artery was established. RESULTS AND CONCLUSION: ①Light microscope results showed that at week 12 after graft, endothelial cells were sparsely distributed throughout the neointima surface near the stoma; at month 6 after graft, endothelial cells were presented on the whole surface of the patent graft lumen; 1.5 years after graft, lumens of graft vessels were unobstructed, and parts of endomembrane tissues were found chronic inflammation. ②Electron microscope results showed that at week 12 after graft, new vascular endothelial cells were in fusiform shape and arranged regularly; besides, the endothelial cells spread from the stoma to the middle of the graft vessel. After graft for 6 months, the endothelial cells spread from the stoma to the middle of the graft vessel. Endothelial cell colony in the middle of the graft vessel showed leaping and flake-like growth, and the cells were arranged more compactly; moreover, their shapes were more like the endothelial cells of mature vessels. After graft for 1.5 years, the whole vessel wall was covered by tightly arranged endothelial cells, and parts of endomembrane tissues revealed chronic inflammation. These findings suggest that the novel small-diameter bioartificial vascular graft has many advantages, for example, the newborn intima forms early and completely, and endangium can be well reconstructed; in addition, it has good biocompatibility and stability.