提高线栓法大脑中动脉闭塞性兔脑缺血模型稳定性和可重复性的研究

Stability and reproducibility of intraluminal thread approach in making focal cerebral ischemia model in rabbits

目的 探讨提高线栓法在制作兔大脑中动脉局灶性脑缺血模型的稳定性和可重复性的方法。方法 67只雄性新西兰白兔被随机分为 4组 ,其中A组 12只 ,用于进行颈动脉系统血管铸型 ,以观察颈动脉系统的走行特点及分支情况 ;B组 7只 ,为假手术对照组 ;C组 3 6只 ,用于探讨线栓法制作局灶性兔脑缺血模型时最合适的线栓头端直径 ;D组 12只 ,用于对C组的结果进行进一步的验证。对于B组以及C、D组插线成功的动物分别于插线后 3 0min、1h、2h、3h、和 6h行T2WI和DWI检查 ,C组线栓插入颈内动脉小于 4.0cm的动物改行颈动脉系统血管铸型。结果 颈动脉系统血管铸型可以清楚地显示兔颈动脉系统的走行特点及分支情况 ;最适合造成局灶性脑缺血的线栓头端直径是 0 .5 1～ 0 .5 5mm ;当枕动脉起自颈内动脉时线栓很容易进入枕动脉而导致手术失败。通过选择合适的线栓和正确控制插线的方向 ,该模型的成功率由开始的 2 5 %提高至 83 .3 3 %。结论 选择合适的线栓以及熟悉兔颈内动脉系统的解剖及变异情况能够明显提高线栓法在制作局灶性兔脑缺血模型的稳定性和可重复性。

Objective To investigate how to improve the stability and reproducibility of intraluminal thread approach in making focal cerebral ischemia model in rabbits.Methods Sixty-seven male New Zealand white rabbits were randomly divided into four groups:A,B,C,and D.Anatomical casts of carotid arteries were performed in Group A (n=12) to observe the gross morphology of carotid arteries.Control group (Group B,n=7) was sham-operated.The appropriate diameter of thread tip that could lead to focal cerebral ischemia was investigated in group C (n=36) and further validated in Group D (n=12).For the rabbits in Group B,and the rabbits of which the thread had been inserted into ICA successfully in Group C and D,T2WI and diffusion-weighted MR imaging (DWI) was performed at 30 min,1 h,2 h,3 h,and 6 h after the insertion of the thread.For the rabbits of which the thread couldn't be inserted into ICA more than 40 mm in Group C,the anatomical casts of carotid arteries were then performed.Results The course and bifurcation of ICA could be displayed clearly on the anatomical casts of carotid arteries.The appropriate diameter of thread tip that could lead to focal cerebral ischemia was 0.51-0.55 mm.When the occipital artery originated from the ICA,the thread tip was easily inserted into the occipital artery instead of the ICA and resulted in the failure of the operation.By choosing appropriate thread and properly controlling the direction of the thread tip,the successful rate was improved from the initial 25% to 83.33%.Conclusion To choose an appropriate thread and get familiar with the anatomy and variation of ICA can obviously improve the stability and reproducibility of intraluminal thread approach in making focal cerebral ischemia model in rabbits.