自体组织构建小口径血管的实验研究

目的在大鼠自体肌肉内预置硅胶棒后形成结缔组织管,观察将其作为血管替代物移植于腹主动脉后的组织结构变化。方法取Wistar大鼠48只随机分为对照组和2、4、6个月移植组。先在腹壁肌肉内埋植直径0 .2cm、长1.5cm硅胶棒,6周后将硅胶棒周围形成的结缔组织管状物作为血管替代物移植于大鼠腹主动脉,在移植术后2、4、6个月分别观察血管通畅情况,光镜、透射及扫描电镜观察替代物的组织结构。结果1.血管替代物移植于腹主动脉后2、4、6个月血管全部通畅。2 .组织学观察平滑肌细胞及内皮细胞在2个月组替代物仅中段少部分未覆盖,4个月组替代物内壁覆盖连续,6个月组与对照组相近,且在近吻合口端可见弹力膜形成。结论1.自体组织所形成的替代物移植于腹主动脉后6个月后管腔通畅良好。2 .移植后6个月的替代物管壁厚度及组织结构已接近正常血管。

Construction of small-caliber vessels by autogenous connective tissue: an experimental study in rats

Objective To observe the structural changes of autogenous connective tissue tubes when used as substitute of blood vessels. Methods An animal model of abdominal aorta grafting was created in Wistar rats. A silicon rod of 2 mm in diameter and 15 mm in length was embedded in the muscular layer of the abdominal wall. After 6 weeks the connective tissue tube formed around the silicon rod was harvested and used as vessel substitute to bridge the defect of the abdominal aorta. 48 rats were randomly divided into 4 groups, with 12 each. In the control group, 1 cm segment of abdominal aorta was cut and orthotopically grafted. In the experimental groups, defect of abdomial aorta was bridged by the autogenous connective tissue tube. Measurement of patency of the grafts, light microscopic, scanning and transmitting electron microscopic observation for structural changes of the grafts were carried out before grafting and 2, 4 and 6 months after grafting. Results The vessels were found to be patency in all groups. In vascular substitutes of 2 months group, structures of an artery including endothelial cells and smooth muscle cells were present in most part of the intima and media of the vascular wall. Continuous lining of the vascular wall was seen in vascular substitutes of 4 months group. The structures of vascular substitutes of 6 months group were similar to those of the control group. Formation of elastic band was seen in the wall near the anastomosis site. Conclusion Autogenous connective tissue tubes keep good pantency 6 months after being used as vascular substitutes for grafting. By that time the thickness and structures of the graft were similar to those of normal vessels.