Valve-in-Valve Transcatheter Aortic Valve Replacement for Failed Surgical Bioprostheses: Insights from a Single-Center Experience with the Mitroflow Valve

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) has become a mainstream, less invasive alternative to redo surgery for failed surgical aortic bioprostheses, but certain surgical valve designs remain a source of concern. The Mitroflow bioprosthesis, with externally mounted leaflets, degenerates earlier than other surgical valves and has historically carried heightened risk of coronary obstruction and residual stenosis during ViV TAVR. We review contemporary ViV TAVR outcomes in the context of our single-center experience of 105 consecutive procedures (2012 to 2025) comparing failed Mitroflow (n=37) with other surgical bioprostheses (n=68). Mitroflow valves failed significantly earlier compared to other surgical valves (8.46 vs 11.16 years, p<0.001), yet ViV TAVR achieved equivalent mean gradient improvements from 34 to 18 mmHg which remained stable at one year, equivalent Valve Academic Research Consortium-3 (VARC-3) complication rates, and equivalent survival at 30 days, one year, and five years, with no difference in Kaplan-Meier survival through eight years. These results contrast with early registry experience and suggest that the excess hazard historically attributed to the Mitroflow valve may be mitigated by computed tomography-based coronary risk assessment, preferential use of supra-annular self-expanding platforms, and selective use of adjunctive techniques such as leaflet modification and bioprosthetic valve fracture. ViV TAVR can be offered safely and effectively even in anatomically unfavorable surgical prostheses.