新型室间隔缺损封堵器的动物实验研究

目的:在犬室间隔缺损动物模型上观察新型室间隔缺损封堵器的性能及其生物相容性.方法:通过右颈内静脉途径穿刺室间隔制备犬室间隔缺损模型,模拟临床经导管封堵过程,经鞘管送入新型室间隔缺损封堵器,闭合人工制备的室间隔缺损.应用心室造影和心脏超声观察封堵器位置及三尖瓣、主动脉瓣功能.术后1、2、3、4个月分别处死动物行组织学检查,观察封堵器周围及表面纤维组织和内皮覆盖情况.结果:6条犬成功制作室缺模型并成功封堵,术后心室造影及超声显示封堵器位置固定良好,不影响三尖瓣、主动脉瓣启闭功能;全部实验犬封堵器位于相当于隔瓣下型膜周部室缺的位置,所有封堵器均被薄层的新生内膜覆盖,金属丝无变色、无腐蚀,肉眼观察封堵器表面光滑,光镜和电镜检查显示无明显的炎症反应及纤维组织增生;术后3个月封堵器表面内皮细胞完全覆盖;术后4个月扫描电镜观察金属丝无腐蚀.肺、肝、脾、肾、胰等组织无血栓栓塞、炎症表现.结论:新型室间隔缺损封堵器具有操作简便、使用安全及良好的生物相容性,可安全地用于膜周部室缺的封堵.

Evaluation of new-type ventricular septal defect occluder in animal model

Objective:To evaluate the safety and efficacy of transcatheter closure of ventricular septal defect(VSD) with new-type occluder in canine model. Methods: VSD was created by transcatheter puncture through jugular vein and closed by occluder via 7F delivery sheath under fluoroscopy in the catheterization laboratory. The location of device and function of tri-cuspid valve (TV) and aortic valve (AV) were observed by ventricular angiography and echocardiography. 1,2,3 and 4 months later, the animals were killed and autopsy was conducted. Results : Six dogs with puncture-produced VSD underwent VSD closing procedure successfully. The defect located near membranous septum,similar to paramembranous defect in humans. The occluders had no influence on the function of TV and AV in epicardial echocardiogram and ventriculogram. Gross examination of the occluder revealed no wire breakage or fracture of the device. Looking from both side,the devices were covered with a smooth intact neointimal layer in all dogs. Endocardial cells partially covered the surface of occluder after 1 month,and fully covered the surface after 3 months. There was no evidence of corrosion on the surface of the nitinol wire removed from the dog after 4 months. Light microscopic examination of the liver,kidney,lung and spleen showed no evidence of embolization and inflammation. Conclusion: Transcatheter VSD occlusion with new-type occluder is safe,feasible and effective. Retrievability and good biocompatibility give the occluder a good prospect in future clinical use.