IC: There is still a concern that the risk of stroke or transischemic attact (TIA) is still higher in patients who underwent TAVI as opposed to surgery. How can this be improved? Do we need a better post-operative antithrombotic therapy?
　　Dr. Applegate: Stroke and TIA are still a major concern with TAVI. An MRI before and after a TAVI will reveal an alarmingly high incidence of new lesions， even though these are not clinically expressed. These data suggest that the procedure may be causing embolization of materials. Is this thrombosis? Is this part of the friable valve being disrupted and thrown off? Most people agree that this is related to the valve manipulation itself. There have been some small， transcranial doppler studies done during TAVI. It turns out the intense signals released suggest that emboli potential stems from valve manipulation and not the movement of the catheter along the aorta. This is way the transapical approach originally generated a lot of enthusiasm， only to realize similar results. Newer antithrombotic therapies will probably not be able to address this either. Development is needed in shielding. There are a number of different devices that are looking at putting filters in the carotids， using EMBO SHIELDS and transverse hemiarch. I think it remains to be seen where we are going， but this is an issue that needs to be addressed.
　　《国际循环》：目前仍担心接受TAVI治疗较外科手术的卒中或短暂性脑缺血发作（TIA）发生率高。如何改善？是否需要术后抗栓治疗？
　　Applegate教授：卒中和TIA仍是实施TAVI时主要担心的事情。TAVI前后进行MRI检查会发现出现新病灶的几率相当高，尽管没有临床表现。数据显示，TAVI操作可能导致瓣膜系统的栓塞。这是不是血栓形成？这是不是易碎瓣膜破坏和脱落的表现？大多数人认为，这与植入瓣膜的操作相关。部分TAVI期间开展的小样本经颅多普勒超声研究显示，强信号提示栓子潜在地来自于植入瓣膜的操作，而不是来自于导管通过主动脉的过程中。因此，经心尖的方式引起了大家极大的兴趣，但是结果相似。新型抗栓药物可能也无法解决这个问题，需研发防护装置。目前有一系列的防护装置，如在颈动脉放置滤网，采用EMBO SHIELDS和Hemiarch装置。我对未来的发展方向拭目以待，但这的确是我们需要解决的问题。

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