兔颈动、静脉移植桥血管狭窄模型的建立及其电镜观察

目的：建立兔颈动、静脉移植血管桥动物模型，观察移植桥血管内膜增生和狭窄的电镜下表现。方法：通过兔双侧颈动脉进行动脉桥和静脉桥的移植，形成双侧移植血管桥再狭窄动物模型。在第8周施行血管桥移植手术的同时留取右侧颈动静脉标本作为对照血管，再分别于第12周、16周和第20周分别处死模型兔，采集移植桥血管标本，在光镜下测量其内膜厚度、面积、狭窄度，并进行电镜观察。结果：颈动脉和颈静脉桥移植后，随着时间的延长，桥血管的出现平滑肌迁移，脂质沉积，内膜增生，血管狭窄等改变，且以静脉桥血管的病理改变更为明显。结论：在兔形成动脉粥样硬化病变基础上，进行双侧颈动脉血管桥的移植，建立兔双侧颈动脉移植血管桥再狭窄动物模型，有利于设立自身对照，研究术后动静脉桥再狭窄差异机制；建立动、静脉桥后，位于血管中膜的平滑肌细胞出现向血管内膜迁移现象，说明中膜平滑肌细胞迁移进入内膜导致新内膜形成是血管再狭窄的重要环节。

Construction of a Vascular Graft Atherosclerotic and Stenotic Rabbit Model and Its Observation Under Scanning Electron Microscope

Objective： ABSTRACT Objective： To construct a vascular graft atherosclerotic and stenotic rabbit model and to ob- serve the intimal hyperplasia and stenosis of the transplant graft under scanning electron microscope. Methods：Studies were performed by using New England rabbits, weight 2-2.5kg, animals were fed with high fat diet to mimic the pathology of coronary atherosclerosis in human for 8 weeks, and to subjected to premedication, anesthesia. A longitudinal incision was made on the median of neck to expose bilateral carotid arteries and veins, a 1 cm segment of right carotid artery was isolated, which both cut ends were then beveled to about 45 degree, both hubs of right carotid artery anastomosed to ipsilateral vein by end-to-side anastostomotic technique under magnification with continuous 8-0 polyprolene suture, and both sides of the right carotid vein away from anastomosis arteriovenosa were ligated to form a vein graft, then the isolated artery was implanted in to left carotid artery by an end-to-end anastostomotic technique to form an artery graft. The graft was de-aired though the suture line before the suture of the second anastomosis was tied, the animals were fed with high fat diet and 6 couples of grafts were removed in the 12th week, 16th week and 20th week, respectively after operation, to fixe the grafts with the use of 10% paraformldehyde solution, and the processed for wax embedding. Transverse （0.4um） were stained with haematoxylin-eosine, and examine neointimal proliferation under a light microscope, and assay the area of vessel lumen, intima and media quantitatively by computer-aided planimentry and . observation by scanning electron microscope. Results： At the 8th week of experiment, the sigh of atherosclerosis of bilateral carotid arteries appeared. The SMC of graft migration from media to intima, the neointimal proliferation of graft and narrow luminal area occurred after implantation, especially in 20 week of experiment.Conclusion： We have established an experimental animal model for restenosis in grafts of rabbits＇ bilateral carotid arteries on the basis of aortic atherosclerotic lesions, which is conducive to the establishment of self-control and studying the mechanisms of restenosis of vascular graft.The neointimal proliferated and the SMC migrated after operation, especially apparently in the vein graft.