两种不同类型左心耳封堵器的动物实验研究

Assessment of two different types of left atrial appendage occluder

目的评价单盘圆柱型及双盘分体型两种不同左心耳封堵器进行动物左心耳封堵的可行性及安全性。方法 14只健康实验犬使用单盘圆柱型或双盘分体型左心耳封堵器经股静脉途径进行左心耳封堵,术中左房造影评价封堵后效果;对非预期死亡的实验犬立即进行大体标本检查分析死因,存活的实验犬分别于术后第45天、80天、110天、15月处死,对封堵器表面组织行HE染色及DAPI、CD31免疫荧光评价内皮化程度。结果 6只实验犬使用单盘圆柱型封堵器进行左心耳封堵,5条实验犬于术后30 min-8 h死亡,1条实验犬存活至15月后处死;大体心脏解剖发现4条实验犬封堵器表面均存在大量血栓,存活的1条实验犬封堵器表面约1/5未见新生组织覆盖;8只实验犬使用双盘分体型封堵器进行左心耳封堵,7例实验犬完全封堵;术后110 d新生组织完全覆盖封堵器表面,HE及免疫荧光染色呈现完整内膜形成,并可见新生血管。结论单盘圆柱型封堵器植入左心耳后急性血栓发生率及即时死亡率高;双盘分体型左心耳封堵器用于封堵左心耳,器械相关并发症低,左心耳封堵术后4月覆盖盘完全完整内膜化。

Objective To evaluate the feasibility and safety of two different types of left atrial appendage occluder with a single disc cylinder or double disc device.Methods Fourteen healthy canines were subjected to left atrial appendage closure(LAAC)with the single disc cylinder or double disc device percutaneously.Closure was evaluated by left atrial angiography.The cause of death was analyzed by gross specimen examination of dogs that had died unexpectedly.The canines were sacrificed post-procedure at 45,80,110 days,and 15 months.Endothelialization of the device surface was evaluated by HE staining,immunofluorescence staining of CD31,and DAPI staining.Results Single disc cylinder devices were implanted in six canines,five of which died within 30 min to 8 h post-procedure,and one canine survived until 15 months.A large number of blood clots were formed on the device surface in four canines,and one-fifth of the device surface in the surviving canine was not covered by new tissue.Double disc occluders were implanted successfully in eight canines.The left atrial appendage of seven canines was sealed completely and a small residual shunt was observed in one canine immediately post-procedure.New tissue had covered the sealing disc completely on day 110.HE and immunofluorescence staining confirmed complete intima formation and neovascularization within 4 months.Conclusions The incidence of acute thrombosis and the mortality rate of LAAC with a single disc device were high.LAAC with double disc devices had less device-related complications and neointima formation was completed by 4 months post-procedure.