经胸左心耳穿刺行左心耳夹闭术的动物实验研究

Experimental study of thoracotomy implantation of a self-made left atrial appendage occluder in animal models

目的观察经胸左心耳穿刺入径置入自制左心耳封堵器夹闭左心耳的可行性、安全性和有效性。方法选用健康、成年犬12只,使用自主研制的镍钛合金左心耳封堵器经胸左心耳穿刺入径行左心耳夹闭术。术后1周(1只)、1个月(2只)、3个月(2只)、6个月(2只)、1年(4只)分别通过心脏超声、心脏大体标本观察及光镜检查等,评价经胸左心耳穿刺置入自制左心耳封堵器的可行性、安全性及封堵器置入后内皮化过程。结果实验犬左心耳封堵器置入成功率为91.7%,1只犬在封堵器置入后因空气栓塞致心室颤动死亡。术后1周、1个月、3个月、6个月、1年分别处死实验犬,心脏大体标本观察显示封堵器未见移位,封堵器表面未见血栓形成和赘生物附着。术后1周封堵器左心房、左心耳侧盘面均未见明显组织覆盖;术后1个月封堵器左心房侧盘面可见光滑平整的薄层组织覆盖,病理证实为纤维组织和内皮细胞,封堵器边缘与周围心房壁部分融合,左心耳侧盘面与心包无粘连,可见部分纤维组织包绕;术后3个月、6个月、1年封堵器左心房侧盘面光整,覆盖组织增厚,封堵器边缘与周围心房壁完全融合,左心耳侧盘面光整,完全被纤维组织包绕。结论经胸穿刺左心耳入径置入自制封堵器封闭左心耳的方法简单、安全、有效。

Objective To observe the feasibility, efficacy, and safety of the thoracotomy implantation of a self-made left atrial appendage occluder in animal models,and to provide experimental evidence for further clinical research and application. Methods Thoracotomy and implantation of self-made（ nitinol） LA occluder were performed in 12 healthy dog models. Implantation of occluder was guided by DSA and TTE. Dogs were sacrificed in 1 week and 1,3,6,12 month respectively after device implantation and while tissue samples were obtained for gross examination and histological examination to evaluate the endothelialization after implantation of the new occluder and to observe complications including superficial thrombus formation. Results The procedural success rate of implantation by thoracotomy was 91%. One animal died of VF because of air embolism after implantation. The dogs were sacrificed in 1 week and 1,3,6 and 12 months after device implantation respectively. No dislocation of occluder nor fracture of the nitinol wires were found. There was no superficial thrombus formation or regetation. The surface of the LA-disk and the LAA-disk of the occluder was not covered with tissue after 1 week,and were covered mainly with smooth lamellar lucency tissue after 1 month. Histological examinations revealed that the surface was fibrous tissue and endothelial cells. The edge of the occluder confluenced partly with the surrounding of the endocardium of the atrial wall. The surface of the LAA-disk was covered with fibrous tissue. The flat surface covering on the LA-disk of the occluder was thickened,and the edge of the occluder confluenced completely with the surrounding of the endocardium of the atrial wall after 3,6 and 12 months. Conclusions The approach of implantation of a self-made nitinol left atrial appendage occluder by thoracotomy in is feasible,safe and effient in animal models.