**2. Conclusions**

Redo-SAVR traditionally was the only treatment modality for failed bioprostheses. Many elderly patients are not good candidates for a second operation or do not desire to go through a redo-sternotomy. The arrival of transcatheter technology has transformed the landscape of therapy for aortic valve disease and structural valve deterioration. More than a decade after the first reported ViV-TAVR case, this procedure is now consistently performed worldwide in most patients with failed bioprosthetic valves. ViV-TAVR is safe and effective and now a credible, approved alternative treatment option for failed surgical bioprosthetic valves in patients deemed at a prohibitive risk for redo surgery. It is clear that ViV-TAVR is more complex than TAVR in native valves, with a greater risk of peri- and postprocedural complications. A super specialised, multi-disciplinary team with high-volume practice, precision preintervention planning, using multimodality imaging is required for optimum results.

With the increasing use of TAVR in younger patients and the increasing use/choice of bioprostheses for SAVR in younger patients, a future with a not inconsiderable population with failed bioprostheses is expected. A downward risk-drift for ViV-TAVR use is also anticipated. Therefore, the real future challenge is identifying what is the best lifetime treatment strategy for aortic valve disease for the individual, as primary intervention is of pre-dominant importance in dictating the individual's subsequent treatment course.

Further, improving ViV-TAVR outcomes is likely to centre around ameliorating and mitigating elevated postprocedural gradients, coronary obstruction risk and leaflet thrombosis. However, efforts focused upon (A) improving bioprosthesis durability/longevity and (B) optimising operative strategies for redo-SAVR are equally important and should be maintained. Providing a good solution for the failed SAVR and investigation into providing an acceptable technical answer for the failed TAVR and also for a potential third valve after a failed ViV-TAVR also merit consideration as part of the lifetime management of aortic valve disease.
