Transcatheter valve-in-valve implantation is an emerging treatment option for high-risk patients with failing aortic bioprostheses. The presence of the prosthesis stents is thought to prevent coronary artery obstruction, a known complication of transcatheter aortic valve implantation in the native aortic valve. The Sorin Mitroflow aortic bioprosthesis (Sorin Group, Saluggia, Italy) has a particular design in that the pericardial leaflets are mounted outside the valve stent. As a consequence, the pericardial leaflets of this prosthesis may be displaced well away from the stents during the deployment of transcatheter valves. This might explain why both the cases of coronary occlusion following valve-in-valve implantation reported to date occurred in patients with a malfunctioning Mitroflow bioprosthesis. We describe a patient with a malfunctioning 25 mm Mitroflow bioprosthesis successfully treated by percutaneous transcatheter valve-in-valve implantation, and discuss the role that balloon aortic valvuloplasty plays in the performance of this delicate procedure. © 2012 Wiley Periodicals, Inc.