自制新型封堵器堵闭犬左心耳的实验研究

A novel device for the occlusion of left atrial appendage: an experimental study in canine models

目的在实验犬模型上评价新型左心耳封堵器的可操作性、安全性和生物相容性。方法用自行研制的新型左心耳封堵器经导管封堵20只犬的左心耳,并于术后2周至6个月观察封堵器表面内膜生长情况、有无血栓和移位。采用组织学及扫描电镜观察封堵器表面内膜及内皮生长情况。透射电镜检查内皮及组织细胞有无生长异常。结果 14只犬即刻成功植入封堵器。术后检查封堵器无移位,表面无血栓,左心耳完全封闭。光镜及扫描电镜检查显示,术后1个月封堵器表面覆盖纤维内膜组织,上有内皮细胞生长,3个月则完全被内皮覆盖。透射电镜检查见内皮细胞、封堵器附近心房肌肌节及线粒体形态、结构正常。肉眼及光镜下见肺、脾、肝、肾无栓塞或梗死表现。结论新型左心耳封堵装置操作方便、安全可行,长期植入的安全性有待进一步研究。

Objective To evaluate the feasibility,safety and biocompatibility of a novel device designed by the authors for the occlusion of left atrial appendage（LAA） in canine models.Methods The occlusion of LAA was performed in 20 experimental dogs by using a novel LAA occluder,which was delivered to the LAA through a transseptal catheter.During the period of 2 weeks to 6 months after the procedure,the dogs were kept under observation for the device healing,migration,perforation and the formation of thrombus.Both scanning electron microscope（SEM） and transmission electron microscope（TEM） were used to examine the endothelial growth on the surface of the occluder and the structure of the endothelial cells.Results Of the total 20 dogs,the novel device was successfully implanted in14.The LAA was occluded completely in 13 dogs.No mobile thrombi caused by the implantation procedure were observed.Endothelialization of the atrium-facing surface was observed at one month after the procedure,and the surface was completely covered with endothelial cells at 3 months after the treatment,which was confirmed by gross,histological and SEM examinations.TEM examination showed that the structure of endothelial cells,the mitochondrion and sarcomere of atrial cardiocyte were all normal.Gross and light microscopic examination of the kidney,lung,spleen and liver showed that there was no evidence of embolism or infarction.Conclusion The novel device is safe and feasible for the occlusion of the LAA in experimental dogs.Further study is needed to observe its long-term safety.