Objective · To explore the standardized steps for building an animal model of vein graft restenosis by suture anastomosis and to verify the effectiveness via evaluation experiments. Methods · Thirty-two female SD rats underwent interposition bypass grafting of the autologous external jugular vein to the carotid artery for building a model of vein graft restenosis. Modelling steps were optimized. The success rate and modelling effects were evaluated using electron microscopy, HE staining and optical microscope, and color Doppler ultrasonography. Results · All rats successfully underwent vein graft surgery and survived the surgery. Vein grafts were all well without thrombosis or necrosis during 45 days of follow up except for one graft that developed thrombosis. The
success rate of modelling was 96.8%. Electron microscopy observation showed that anastomoses and sutures were almost completely covered with regenerated vascular endothelium 14 days after surgery with irregular bulges in vascular intima due to intimal hyperplasia. Color Doppler ultrasonography suggested that the peak systolic velocity at anastomoses was significantly increased compared with contralateral normal carotid artery 21 days, and especially 45 days after surgery due to venous stenosis. HE staining and optical microscope observation found typical restenosis pathological changes in vein grafts with significant increase in thickness and area of hyperplastic intima. Conclusion · The standardized steps for building an animal model of vein graft restenosis have a high success rate of modelling and favorable repeatability and have been verified via evaluation experiments.