可吸收经胸逆向左心耳封堵器的研制及体外动物实验

目的 设计和制作可吸收经胸逆向左心耳封堵器及输送系统,并用体外封堵实验评价其经胸逆向封堵左心耳的可行性,为后续动物实验奠定基础.方法 使用可吸收材料聚对二氧环己酮(PDO)丝材、聚乳酸(PLA)无纺布及聚乙醇酸(PGA)缝线编织左心耳封堵器.在体外水浴条件下测试可吸收左心耳封堵器的压缩性能、弹性恢复性能及尾部螺纹铆可承受的有效输送释放次数.选取6只健康杂种犬离体心脏标本,直视下在左心耳外上中1/3处穿刺,使用带刻度的输送鞘及封堵器完成体外封堵实验,封堵完毕后解剖心脏,观察封堵器位置和封堵效果.结果 封堵器可顺利收入14F鞘管并完成输送和释放,在鞘管中保留15 min后释放,即刻恢复到原状96％的程度,尾部螺纹铆能承受(5.20±o.75)次的有效输送.6只犬心脏标本全部封堵成功,封堵器释放以后,位置良好,内盘面进入心耳口内少许,左心耳开口呈过度撑开状态,不影响肺静脉血液回流和左房室瓣功能.结论 可吸收经胸逆向左心耳封堵器设计合理,与实验犬左心耳解剖形态匹配,封堵效果确切,可以进行动物实验以迸一步评价采用可吸收左心耳封堵器经胸逆向封堵左心耳的可行性、安全性和有效性.

Development of absorbable transthoracic left atrial appendage reverse occluder and in vitro animal experiment

Objective To design and prepare an absorbable transthoracic left atrial appendage (LAA) reverse occluder and delivery system and to evaluate the feasibility of absorbable transthoracic LAA reverse occlusion by in vitro experiment. Methods A double-disk-shaped absorbable transthoracic LAA occluder was designed using polydioxanone (PDO), poly-L-lactic acid (PLA), and polyglycolic acid (PGA). Compression properties, elastic recovery properties and ultimate sustainable effective delivery times of the tail thread riveting were tested by in vitro water bath. Six isolated dog hearts were punctured at the center of the upper 1/3 axis of left atrial appendage under direct vision,and 14F sheath with scale was used to complete the in vitro experiment of occlusion. The location and effect of the occluder were observed by anatomizing the hearts after closure. Results Absorbable LAA occluder was smoothly delivered by 14F sheath, and instantly released and restored to 96% of original size after placed for 15 min in the sheath. Tail thread riveting could tolerate (5.20±0.75) times effective delivery. Six heart specimens successfully underwent the occluding tests in vitro. We found that the occluder was well located, with the opening disk of the left atrial appendage porting into the opening a little, and the opening was in an over distraction state. There was no influence on blood flow of pulmonary vein and function of the mitral valve. Conclusion The absorbable transthoracic LAA reverse occluder is well-designed and matches the anatomy of the left atrial appendage of canine. Further animal experiment is needed to evaluate the feasibility, safety and efficacy of the absorbable transthoracic LAA reverse occluder.