Redo-TAVR (TAV-in-TAV) Best Practices Part 1: Short-in-Short and Short-in-Tall: A Heart and Valve Collaboratory Document.

Transcatheter aortic valve replacement (TAVR) has created a growing population of patients who require redo-TAVR (TAV-in-TAV) for structural valve deterioration. Short-frame balloon-expandable valves implanted within failed short- or tall-frame transcatheter valves ("short-in-short" and "short-in-tall") pose specific challenges, including coronary risk assessment, valve sizing, anchoring, and preservation of coronary access. Under the auspices of the Heart and Valve Collaboratory, an international multidisciplinary panel of experts reviewed bench and clinical data and synthesized contemporary best practices into a pragmatic workflow for redo-TAVR. This document standardizes key anatomic definitions, outlines computed tomography-based strategies for in vivo sizing, and details recommended approaches to predilatation, deployment techniques, and postdilatation. By harmonizing terminology and stepwise planning across imaging, interventional, and surgical teams, this document aims to simplify procedural decision-making and improve safety, coronary preservation, and hemodynamic outcomes in patients undergoing short-in-short and short-in-tall TAV-in-TAV procedures.