小口径异种血管作为冠状动脉旁路移植术桥材料的研究

目的 研制和评价一种新型小口径异种血管，为冠状动脉旁路移植术（CABG）提供新的移植血管来源。方法 将犬颈动脉采用酶-去污剂法进行脱细胞处理，脱细胞后随机分为两组，肝素结合组（n=24）：进一步进行肝素结合处理；肝素未结合组（n=24）：仅脱细胞作为对照。两组的脱细胞异种血管同时分别植入同一只兔左、右侧颈动脉，在3周、3个月和6个月时用B超观察移植血管的通畅情况；3个月和6个月时分别取材行组织学、电子显微镜及免疫组织化学检查。结果 犬颈动脉细胞被完全去除，肝素结合于血管管壁全层。脱细胞异种血管植入兔颈动脉后两组均无血管阻塞，而肝素结合组血栓形成少于肝素未结合组。移植后3个月两组中无血栓形成的血管管壁均出现大量平滑肌细胞，而内腔由内皮细胞覆盖。结论 酶-去污剂联合肝素处理的犬颈动脉，有可能作为CABG的一种新型小口径异种移植血管。

Experimental Study of Small-caliber Vascular Xenograft for Coronary Artery Bypass Grafting

Objective To develop a new small-caliber vascular xenograft and evaluate the feasibility of xenogenic artery for coronary artery bypass grafting.Methods Canine carotid arteries were decellularized by detergent and enzymatic extraction.All decellularized xenografts were randomly divided into two groups.Heparin-linked group(n=24): grafts were then covalently linked with heparin.Non-heparin-linked group(n=24): as control.Xenografts in two groups were implanted in rabbits' left and right carotid artery respectively as bypass grafts.Graft patency was checked by ultrasonography after 3 weeks,3 and 6 months.Grafts were harvested after 3 and 6 months.Microscopic observation and immunohistochemical staining were performed.Results All the cells were removed while the extracellular matrix were well preserved observed.Heparin was successfully linked to the grafts through their whole thickness.There was no obstruction at both sides after implantation of the grafts,while less thrombus was found in the decellularized heparin-linked grafts than in the other side.Smooth muscle cells densely populated the graft wall and endothelial cells covered the lumen at 3 months after implantation.Conclusion(Canine common) carotid artery treated by detergent and enzymatic extraction and heparin linkage may be a new small-caliber vascular xenograft for coronary artery bypass grafting.