Role of real-time three-dimensional epicardial echocardiography in a novel transcatheter treatment techniques of mitral regurgitation:an acute in vivo animal study

Abstract

Objective To evaluate the usefulness of real-time three-dimensional intraoperative epicardial echocardiography (RT-3D IEE) in the process of transapical mitral valve repair and a new device′s efficacy in an animal model. Methods Acute mitral regurgitation (MR) was induced in 18 anesthetized domestic pigs as MR group by cutting chordae supporting the segment of the leaflet (A2, n=9; P2, n=8; P3, n=1), while 15 pigs received no cutting chordae were chosed as normal mitral valve (NMV) group.The ValveClamp procedures were then transapically performed either on the prolapsing segment (MR group) or A2/P2 segment (NMV group) respectively solely under 3D epicardial echocardiographic guidance. Epicardial echocardiography was obtained before and after transcatheter interventions. Thirty days later all pigs were humanely killed to verify the location of implanted devices. Results In normal group, the preoperative max and mean mitral valve pressure gradient was higher than postoperative those (P 0.05). The autopsy report demonstrated that all ValveClamp devices were precisely placed to clamp either the prolapsing segments (MR group) of mitral valve or A2/P2 segments (NMV group), respectively. Conclusions Real-time three-dimensional epicardial echocardiography can independently monitor the new transcatheter mitral repair technique-ValveClamp, facilitating the overall procedure. Transapical implantation of ValveClamp device under epicardial echocardiographic guidance is effective in reducing acutely induced mitral regurgitation. Key words: Echocardiography, intraoperative epicedial; Transcatheter mitral valve repair; Mitral regurgitation