Redo-TAVR (TAV-in-TAV) Best Practices Part 2: Tall-in-Short and Tall-in-Tall

Transcatheter aortic valve replacement (TAVR) has created a growing population of patients who require redo-TAVR (TAV-in-TAV) for structural valve deterioration. Tall-frame self-expanding valves implanted within failed short- or tall-frame transcatheter valves ("tall-in-short" and "tall-in-tall") present distinct challenges related to anchoring, constrained expansion, valve alignment, and the risk for coronary obstruction or sinus sequestration driven by the resulting neoskirt plane. Under the auspices of the Heart and Valve Collaboratory, an international multidisciplinary panel reviewed bench and clinical data and synthesized contemporary best practices into a pragmatic procedural workflow for redo-TAVR in these settings. This consensus document standardizes key definitions, outlines computed tomography-based strategies for in vivo sizing and risk stratification, and details recommended approaches to predilatation, deployment technique, postdilatation, coronary protection and leaflet modification, or hybrid surgical alternative when needed. A structured troubleshooting guide is provided to support safe, reproducible execution and coronary preservation.