The Role of Preprocedural CT in Redo Transcatheter Aortic Valve Replacement: A Radiologist's Perspective.
As transcatheter aortic valve replacement (TAVR) has become a viable option across all surgical risk levels, younger patients are anticipated to outlive the durability of their index transcatheter heart valve (THV). When a THV fails, cardiac CT is an important tool to assess the mechanism of THV failure and aids in the differentiation between structural and nonstructural THV dysfunction mechanisms. After the identification of the index THV dysfunction mechanism, CT guides the sizing and selection of the new THV type. While the principles of preprocedural redo TAVR (often called TAV-in-TAV) CT assessment overlap with those for patients undergoing TAVR of surgical bioprosthetic valves, the assessment is different in several ways. These differences are primarily related to the need to evaluate the characteristics of the index THV and the degree of commissural and coronary alignment achieved during the index TAVR procedure, which affect the selection of the type and size of the new THV and determine the risks of coronary obstruction and impeded future coronary access, as well as the potential for leaflet modification. Keywords: Applications-CT, CT Angiography, Transcatheter Aortic Valve Implantation/Replacement, TAVI/TAVR Supplemental material is available for this article. ©RSNA, 2026.