Transcatheter valve-in-valve for failed bioprosthetic valves (pp. 307-326)
Authors: (Gurvitch R, Je J, Cheung A and John Webb)
Abstract: All bioprosthetic heart valves, if given sufficient time, can be expected to eventually fail. Despite this, such valves are often favored over mechanical versions to avoid anticoagulation and the associated increased risk of bleeding . When bioprosthetic valves degenerate, repeat cardiac surgery is often at an increased risk given the nature of re-do cardiac surgery and the frequently advanced age of patients requiring such operations . Certain co-morbidities such as advanced age, reduced ejection fraction, pulmonary disease and length of cardiopulmonary bypass time have been identified as independent predictive factors of poor outcomes following re-do surgery for failed aortic and mitral bioprostheses  .
In recent years, transcatheter heart valve (THV) implantation for stenosed native aortic valves has evolved as a viable alternative to open heart surgery particularly in high-risk surgical patients[6-8]     . As experience with the procedure widened and clinical outcomes improved, the concept of treating surgically degenerated valves using similar transcatheter techniques became a possibility. Such treatment is often referred to as ―valve-in-valve‖ (VIV) implantation, as the new THV is implanted inside the degenerated bioprosthesis. In this chapter, we will review the techniques, outcomes and challenges of VIV therapy for failed surgical bioprostheses in the aortic, mitral, tricuspid and pulmonary positions.