利用脱细胞基质预构小口径组织工程血管的实验研究

目的 在犬腹腔内预置脱细胞基质后形成结缔组织管,观察将其作为血管替代物的力学特征及移植于自体股动脉后的组织结构变化.方法 在犬腹腔内埋置长8～12 cm用硅胶棒支撑的制备好的脱细胞基质,3周后将硅胶棒周围形成的管状物作为血管替代物移植于自体股动脉,同时对此管状物作力学、组织学检测及与颈动脉、股静脉的对比分析.在移植术后6个月观察血管通畅情况.光镜、透射及扫描电镜观察替代物的组织结构.结果 ①血管替代物的力学性能弱于正常动脉而强于正常静脉.②组织学观察:形成的管状物内腔有少量的间皮细胞黏附;弹性纤维、胶原纤维结构较完整;纤维网中充满成纤维母细胞.6个月后内皮细胞在替代物内壁覆盖连续,平滑肌细胞与对照组相近.③移植6个月后脱细胞基质组血管全部通畅.结论 ①用脱细胞基质预构的血管替代物力学性能符合血管移植、血运重建的需要.②所形成的血管替代物移植6个月后组织相容性良好,替代物管壁厚度及组织结构已接近正常血管.

An experimental study of small-caliber tissue engineering vessels with acellularmatrix

Objective To observe the mechanical properties of the prefabricated connective tissue tube as blood vessel substitute and its changes after implantation at the femoral artery. Methods The acellulannatrix tube of 8-12 cm in length with a silicone rod inside it was implanted into dog peritoneal cavity. 3 weeks lair, a new formed tube around the silicone rod was transferred to the femoral artery as blood vessel substitute. The mechanical properties and histological examination of the blood vessel substitute were assessed and compared to those of the carotid artery and vein. 6 months after transfer, the patency of the blood vessels substitute was observed. The histological change was studied by light microscopy, scanning and transmitting electron microscopy. Results ①The mechanical properties of blood vessel substitute was not as strong as artery, but better than the vein. ②there were elastic and collagen fibers with many fibroblasts around the tube wall, but few mesothelial cells around the inner wail. All of the blood vessel substitutes (n=6) were found to keep pateney and the structure of the blood vessels substitutes became similar to femoral artery 6 months after they had been grafted to the femoral artery. Conclusions These results suggest that tissue engineering in vivo is a good approach to construct vessels substitute. The tissue tubes made in dog's peritoneal cavity have good condition when it is used as a blood vessel substitutes.