Name the Cardiac Device • Xray of the Week
Figure 1. Name the cardiac device.
Figure 2. A: Plain radiograph demonstrating the TAVR (red arrows). Note on the plain xray the TAVR aligning with the expected location of the aortic root. B: Axial CT image of the chest showing TAVR (green arrow). Note the location of the normal mitral valve (yellow arrows) C: Coronal CT image of the chest showing TAVR (green arrow).
Figure 3. Video demonstrating placement technique for TAVR (Edwards Sapien 3).
Aortic valve replacement via surgical (surgical aortic valve replacement or SAVR) and minimally invasive approaches (transcatheter aortic valve replacement or TAVR) have become the gold standard in treatment for patients with severe aortic stenosis (AS). Prior to TAVR, which was FDA approved in 2011 for severe AS, and related procedures, the only options available to patients were diuretics and balloon valvuloplasty – neither of which effected long term events. Indications for aortic Valve (AV) replacement include patients with symptoms, and those that are asymptomatic with LVEF less than 50%. Imaging plays a crucial role before, during and after the procedure, and especially with TAVR as there is decreased visualization with this procedure compared to SAVR.
Pre-op imaging remains a crucial aspect to TAVR as the aortic valve maintains a complex geometrical structure making measurements a hard task. Additionally, in severe AS the valve annulus may morph in shape which can lead to an underestimation of size. Thus, 3D transesophageal echocardiography (TEE) and multi-detector computed tomography (MDCT) remain the modalities of choice. Studies have specifically shown that TEE measurements are best obtained during mid-systole and while MDCT measurements can be obtained at any point during the cycle, they best correspond to those of TEE when obtained during diastole. There does remain some concern though that 3D TEE tends to underestimate to the tune of 9-12% compared to MDCT, thus overall MDCT tends to be utilized more in practice.
Peri-procedural imaging has traditionally relied upon guidance via TEE requiring general anesthesia but as the shift from general anesthesia towards conscious sedation is being made for the procedure, imaging is now largely done via fluoroscopic guidance. Each modality, TEE, TTE with fluoroscopy, and fluoroscopy alone have all been used for real time imaging during the procedure, and each has its own benefits and downfalls.
Post-procedural imaging relies strongly on a multi-modal imaging approach by way of echocardiography, cardiac CT, and cardiac magnetic resonance imaging, all of which play important roles in discerning between various post-op complications. Suspected paravalvular leak and valvular thrombosis are best imaged via echo and CMR or echo and CCT, respectively. Structural deterioration is best seen via CCT.
1. Corrigan FE, Gleason PT, Condado JF, et al. Imaging for Predicting, Detecting, and Managing Complications After Transcatheter Aortic Valve Replacement. JACC Cardiovasc Imaging. 2019;12(5):904-920. doi:10.1016/j.jcmg.2018.07.036
2. Xu B, Mottram PM, Lockwood S, Meredith IT. Imaging Guidance for Transcatheter Aortic Valve Replacement: Is Transoesophageal Echocardiography the Gold Standard? Heart Lung Circ. 2017;26(10):1036-1050. doi:10.1016/j.hlc.2017.02.018
3. Bleakley C, Monaghan MJ. The Pivotal Role of Imaging in TAVR Procedures. Curr Cardiol Rep. 2018;20(2). doi:10.1007/s11886-018-0949-z
4. Ramlawi B, Anaya-Ayala JE, Reardon MJ. Transcatheter Aortic Valve Replacement (TAVR): Access Planning and Strategies. Methodist Debakey Cardiovasc J. 2012;8(2):22-25. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3405802/
5. Mahmaljy H, Tawney A, Young M. Transcatheter Aortic Valve Replacement (TAVR/TAVI, Percutaneous Replacement). In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2020. http://www.ncbi.nlm.nih.gov/books/NBK431075/. Accessed March 20, 2020.
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Neal Shah is a medical student at The Edward Via College of Osteopathic Medicine (VCOM)–Carolinas and intends on completing his residency within the field of radiology. Prior to medical school, he completed his undergraduate studies at the University of North Carolina at Chapel Hill where he majored in economics and chemistry. During his 4 years there he worked in UNC’s Biomedical Research Imaging Center where he helped develop formulations for iron-oxide nanoparticles used for MRI; it was here that his love for the field of radiology developed. He eventually wishes to also pursue his MBA and hopes to use it to help advance the field of medicine in terms of medical innovation.
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Kevin M. Rice, MD is the president of Global Radiology CME
Dr. Rice is a radiologist with Renaissance Imaging Medical Associates. and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.
Follow Dr. Rice on Twitter @KevinRiceMD
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