The Next Era of Transcatheter Aortic Valve Implantation (TAVI): Fully Repositionable, Re-Sheathable and Retrievable Prostheses?

Transcatheter aortic valve implantation (TAVI) is a great alternative treatment option in high surgical risk and inoperable patients with severe symptomatic aortic stenosis (AS). TAVI is a rapidly emerging technique with a constantly expanding body of evidence. However, the devices, which are commercially available and are currently used widely, have several major limitations. In particular, the inability to reposition/ retrieve/ resheath valves, in addition to several patient selection and procedural limitations, such as the occurrence of moderate to severe paravalvular regurgitation (PVR), the risk of annular rupture, atrioventricular (AV) conduction abnormalities with subsequent pacemaker requirement, vascular complications and associated bleeding, coronary ostial obstruction by the valve, stroke, as well as complex delivery processes, are expected to be overcome with the newer generation valves. Consequently, a number of new transcatheter valve choices have been developed either for clinical study or are in the pipeline, that it is hoped to bring meaningful clinical outcomes compared with the currently commercially available technology. Early data on design modifications have shown significant reductions in adverse outcomes from TAVI.