<Internation Icirculation>:: The TAVI devices have evolved to the 4th generation. In your opinion， what are the advancements and the main problems for these devices now? 

  《国际循环》：TAVI器械已经发展到第四代。目前有哪些进展？主要有哪些不足之处？
 

    Prof Schuler:  The major advantage in the Edwards Sapien devices is the reduction in size. Originally， the diameter of the deployment catheter was 26 Fr which was very big for regular patients and many patients suffered vascular complications due to this large size. This has been reduced now to an 18/19 Fr outer diameter and this makes this device compatible with a CoreValve device which started out with a size of 18 Fr.

    Schuler教授：Edwards Sapien瓣膜的主要优势是体积小巧。起初，输送导管的直径达到26Fr，对大多数患者来讲都太大了，很多患者因此发生血管并发症。目前，导管外径已经缩小到18或19 Fr，因此能够与CoreValve瓣膜（大小为19 Fr）相符合

     <Internation Icirculation>:: What area in these devices still needs further improvement?

 《国际循环》：TVAI器械还有哪些方面有待改进？
 

    Prof Schuler: At the present time， there are two major areas where we need advancement. These relate to precision of deployment. We need to make sure we deploy these devices exactly at the optimal position either for containment of aortic regurgitation or for the non-interference of coronary blood flow.

    Schuler教授：目前主要有两方面需要改进，与输送的准确性有关。我们要确保能够将器械输送到最佳位置，达到抑制主动脉瓣返流或不干扰冠脉血流的目的。