International Circulation: OK. So， share with us what some of the fundamental elements for the success are for TAVI
国际循环：好的，您能否与我们分享一下TAVI手术成功的基本要素是哪些？

Prof. Robert O. Bonow:Fundamental success for the current state- of- the- art is the ability to cross a valve that is heavily calcified ，  expand the valve -- initially with a balloon – and  then to implant inside the aortic annulus a stented bioprosthesis  with very little residual artic regurgitation and without complications that run from device embolization to fracture of calcitic deposits in the embolized coronary occlusion; mal-position of the valve – so that it is not positioned adequately to function normally – and also inadequate dilatation of the stent to fully deploy the valve.  
Prof. Robert O. Bonow: 成功的关键是首先能够穿过严重钙化的主动脉瓣，然后扩张瓣膜，先用球囊扩张，然后在主动脉瓣膜内植入一个生物支撑架，可伴有少量残余的主动脉返流。钙化瓣破坏时小心装置的阻塞和冠脉的栓塞。瓣膜的位置必须放置正确，否则会影响其正常的功能。最后，支撑架扩张不当也无法很好的放置瓣膜。