The Pivotal Role of Imaging in TAVR Procedures

Abstract

Purpose of ReviewTranscatheter aortic valve replacement (TAVR) is underpinned by an array of imaging techniques designed to not only select an appropriately sized implant but also to identify potential obstacles to procedural success. This review presents currently important aspects of TAVR imaging, describing the salient features of each modality as well as recent developments in the field.Recent FindingsThe latest data on TAVR outcomes reflects the increasing experience of operators and the significant role of pre-procedural imaging. Debate continues as to which modality sizes the aortic annulus most accurately, 3D transoesophageal echocardiography (TEE) or MDCT, as well as to whether the merits of real-time peri-procedural 3D imaging guidance outweigh the possible adverse consequences of general anaesthesia which is requisite for intraprocedural 3D TEE.SummaryTAVR is now largely based on pre-acquired roadmaps of the truncal vasculature and intense pre-procedural planning. TEE and Multi-detector computed tomography (MDCT) have been shown to perform similarly in annulus sizing. However, given the complexity of many TAVR patients and the importance of identifying the most suitable pathway to the valve as well as any potentially confounding other structural or functional heart disease, both modalities remain relevant in current TAVR.

Combined Coronary CT-Angiography and TAVI-Planning: A Contrast-Neutral Routine Approach for Ruling-Out Significant Coronary Artery Disease

“…Nonetheless, contrast-enhanced CT is essential for accurate anatomical characterization of the aortic root anatomy and vascular access route, and has helped to substantially reduce peri-interventional complications and mortality since TAVI was first introduced [ 1 , 5 , 7 , 11 ]. Even though pre-procedural CT requires ICM, it helps to identify potential peri-procedural risks, makes the TAVI-procedure more efficient and has, thus, become an integral part of the pre-procedural evaluation, also helping to reduce the amount of ICM needed during implantation [ 11 , 12 ].…”

Does transcatheter aortic valve alignment matter?

“…This suggests that correct alignment may lead to some advantage in terms of sinus flow and reduction of non-physiological vorticity above the native commissures. The design of novel devices improving the rotational control of TAVs, together with the use of advanced medical imaging, such as real-time 3D Computed Tomography-fluoroscopy or 3D transoesophageal echocardiography-fluoroscopy fusion imaging4 5 could bear some benefit.…”

“…The valve implantation is achieved guiding percutaneously a delivery system through the patient’s vasculature using intraoperation 2D imaging techniques, such as angiography or fluoroscopy. However, though these techniques are adequate to provide a sufficiently accurate positioning of the depth of the implantation (axial alignment), they are not ideal to identify the angular position of TAVs, while the use of real-time 3D Computed Tomography-fluoroscopy or 3D transoesophageal echocardiography-fluoroscopy fusion imaging, which would enable rotational alignment of prosthetic and native commissures, is still far from being widespread 4 5. As a result, although designed to reproduce the tri-leaflet layout of the aortic valve, implantation of TAVs in the same leaflet-to-sinus arrangement as in the native aortic root is rather unsystematic 6.…”

Anatomical Considerations and Emerging Strategies for Reducing New Onset Conduction Disturbances in Percutaneous Structural Heart Disease Interventions

“…Emerging imaging approaches such as hybrid technology allowing fusion of TEE and/or CT with fluoroscopy improve 3D visualization, however a key feature absent from these innovative strategies is simultaneous real-time imaging of the conduction pathways. 60,61 That is, although anatomy may be depicted with greater detail, the operator remains blind to the exact location of the conduction pathways, which can vary greatly between patients. Therefore, the introduction of 3D imaging approaches that display both electrical pathways (e.g.…”