Off-label transcatheter aortic valve-in-valve implantation in severe bioprosthetic aortic valve dysfunction after bioprosthetic Bentall operation: a scoping review, case study and proposed approach - Nicholas Wen-Sheng Chew; Rodney Yu-Hang Soh; Gwyneth Kong; Yinghao Lim; Ivandito Kuntjoro (Singapore Medical Journal)