【摘要】 目的观察小口径生物型人造血管移植后6月内不同时期的血管材料腔内面内膜层的组织病理学和扫描电镜变化,探讨研制一种新型小口径生物型人造血管。方法19只健康杂种犬作为实验对象,手术切除3cm颈总动脉,以口径4mm的小口径新型人造血管进行桥接。其中19只犬的19侧颈部随机分为1、8、12、24周四组,各含4、4、6、5条动脉。四组的近、远心端均行端-端吻合术。以彩色多普勒B超监测移植血管2周内通畅情况,并于取材前行颈总动脉DSA造影术,观察人造血管不同时间的通畅率。术后1、8、12、24周分期切取标本,标本经处理后分别作光镜和扫描电镜检查。结果四组19条人造血管除12周组和24周组各1条血管阻塞外,其余血管均通畅。组织病理学及扫描电镜检查显示:植入后1周,血管吻合口处有少量的纤维组织增生混杂有薄层少量红色血栓形成,尚未见内皮细胞生长。移植后8周,宿主组织通过人造血管孔隙长入血管腔内参与移植血管新内膜的形成,新内膜形成较均匀,其中有丰富的胶原纤维组织增生,但仍未见内皮细胞生长。移植后12周,镜下于吻合口处,可见新内膜表面有不连续的内皮细胞生长,且内皮细胞形态成熟,其下的胶原纤维增生更致密;而于人造血管中段,可见不成熟的内皮细胞呈岛状生长,新内膜层结构较吻合口处疏松,其间尚可见炎性细胞生长。移植后24周,通畅的人造血管整段管腔内面均可见内皮细胞生长,吻合口附近新内膜表面可见连续的内皮细胞生长。结论以新型生物型人造血管修复犬颈总动脉缺损是可行的,新内膜形成早和完整,24周内自然内皮化相对满意,是一种很有发展前途的新型人造血管。更多还原

【Abstract】 Objective To observe the histopathological changes of a novel small-caliber vascular graft after implantation in canine theca interna under scanning electron microscope. Method A 3 cm segment of the vascular graft (diameter of 4 mm) was implanted in an end-to-end fashion to bridge the severed carotid artery in 19 healthy dogs. Color Doppler sonography was performed 2 weeks after the operation to observe the patency rate of artificial blood vessel. At 1, 8, 12 and 24 week postimplantation, the arteries (4, 4, 6 and 5, respectively) were collected for optical and scanning electron microscopies after angiography to observe the patency of the arteries. Results Of the total of 19 arteries, occlusion occurred in 1 at 12 weeks and 1 at 24 weeks. Optical and electron microscopies showed that 1 week after implantation, slight fibroplasias and formation of red thrombus could be seen at the vascular anastomosis without endothelial cell lining. At 8 weeks, the host tissue grew into the lumen of the graft through the pores to form uniform neointima consisting of plenty of collagen fibers, but still without endothelial cells. At 12 weeks, discontinuous endothelial cells were seen to grow on the surface of the neointima. In the middle segment of the vascular graft, immature endothelial cells were found to grow in clusters. The structure of the neointima was loose in comparison with that at the anastomosis, with occasional inflammation cells. Twenty-four weeks after grafting, endothelial cells grew over the entire inner wall of the patent graft, and the surface of the neointima at the anastomosis was lined with continuous endothelial cells. Conclusion The vascular graft can be useful for reconstruction of canine carotid artery defect and achieves good endothelialization 24 weeks after implantation.更多还原