实验性家兔颈动脉球囊扩张动脉狭窄动物模型的建立

Establishment of a Stenosis Model in Carotid Artery of Rabbit by Percutaneous Transluminal Angioplasty

30 %～ 5 0 %的再狭窄严重制约了经皮腔内血管成形术治疗效果 ,为探索再狭窄的发病机制以进行干预研究 ,建立家兔动物模型。取颈部正中切口 ,无菌暴露兔右颈动脉 ,在颈内动脉起始部及颈总动脉近心侧距动脉分叉 2cm处用动脉夹临时夹闭 ,自颈外动脉远端结扎并由结扎近心侧穿刺进入导丝、球囊导管 ,撤除颈总动脉动脉夹进行经皮腔内血管成形术。然后在不同时间进行组织学及形态学分析 ,并以左侧颈总动脉作正常对照组。结果发现 ,颈总动脉经皮腔内血管成形术后早期主要病理改变是血栓形成 ,中晚期为血管平滑肌细胞由中层移行到内膜并失控增殖伴有基质增多 ;第 15天管腔出现明显狭窄、内膜增厚。结果提示 ,家兔颈总动脉经皮腔内血管成形术模型模拟了临床经皮腔内血管成形术过程 ,死亡率低、成功率高 。

Aim The efficacy of percutaneous transluminal angioplasty (PTA) is limited by a high incidence of chronic restenosis which has been reported to be as high as 30%～50% within 3～6 months. This study was designed to establish an animal model to study the mechanism of restenosis and methods of preventing restenosis. Methods Right common carotid artery (CCA), internal carotid artery (ICA) and external carotid artery (ECA) were exposed with a mdline linear skin incision in the neck. The right CCA 2 cm proximal to the carotid bifurcation and the right ICA at orifice were temporary occluded by aneurysmal straight clips. The right ECA was ligated at the exposed distal end. A 2.0 cm or 1.5 cm balloon catheter was used to induce injury of the righe CCA. The catheter was introduced into the CCA though a small window opened in the ECA, which is proximal to the ligation site. After the clip of the CCA was removed the deflated catheter was passed through the CCA into the aortic arch. An inflated balloon with 8 atomospheric pressure in the aortic arch was slowly pulled back to the ECA to mechanically expand the righ CCA. At 3rd, 7th, 15th days after the balloon injury, the rabbits were killed and histological and morphometric analysis of the right CCA were performed (left CCA as control). Results Histological and morphometric analysis indicated thrombosis is main changes in early stage and followed by VSMC from media into intima and unregulated proliferation and lead to obviously intimal thicking and stenosis at 15 days after PTA. Conclusion For its adventages such as low mortality, high practicability and good reproduce, the model is an ideal model for study of the mechanism and the prevention of restenosis.