大鼠移植静脉再狭窄模型构建的标准化步骤及评价

Establishment and evaluation of standardized steps for building a rat model of vein graft restenosis

目的·探讨缝合法建立移植静脉再狭窄动物模型的标准化步骤,并通过动物实验对其有效性进行验证。方法·32只雌性SD大鼠,采用颈外静脉移植颈动脉的方法构建移植静脉再狭窄模型,对建模步骤进行优化。应用电子显微镜观察、H-E染色光学显微镜观察及彩色多普勒超声检查评估建模成功率及建模效果。结果·32只SD大鼠均顺利完成桥静脉移植手术,术中无死亡。随访45 d,除1例发生术后桥静脉内血栓形成外,其余均通畅,无血栓形成及坏死,建模成功率达96.8%。电子显微镜观察显示:术后14 d,再生的血管内皮几乎完全覆盖吻合口及缝线,血管内膜可见不规则隆起,为内膜增生所致。彩色多普勒超声评估显示:术后第21、45 d移植静脉狭窄形成后,与对侧正常颈动脉相比,吻合口的收缩期流速峰值明显升高,术后45 d更为显著。H-E染色光学显微镜观察发现典型的移植静脉再狭窄病理改变,增生内膜厚度和面积明显增加。结论·建立的移植静脉再狭窄建模标准化步骤经实验评估验证,其建模成功率高且重复性好。

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.