Cardiac ImagingE2629. Transcatheter Aortic Valve Replacement: A Community Hospital Perspective
Agrawal N, Chandrasekaran B, Kataoka M. St. Vincent Hospital, Worcester, MA
Address correspondence to N. Agrawal (firstname.lastname@example.org)
Background Information: Aortic stenosis is a common valvular disorder of the elderly with high morbidity and mortality if left untreated. Historically, surgery has been the mainstay of therapy, but over the past few years, transcatheter aortic valve replacement (TAVR) performed by interventional cardiology is increasingly used in patients considered poor surgical candidates. Aside from tertiary centers, the procedure is being performed more often at community hospitals, thereby requiring smaller radiology groups to adopt protocol and interpret these studies.
Educational Goals/Teaching Points: TAVR is becoming more popular as a noninvasive method of correcting aortic stenosis. TAVR is performed as a multidisciplinary approach with radiology playing a crucial role in preprocedural evaluation of the aortic annulus. Prosthetic valve positioning is of utmost importance, as improper implantation leads to suboptimal results.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: Adequate noninvasive imaging assessment is an essential step in preprocedural TAVR planning, and is required to avoid postprocedural complications such as aortic regurgitation, valve embolization, annular rupture, and patient prosthetic mismatch. CT angiography plays a critical role in evaluating aortic annular size, including diameter, area, and circumference, as well as in acquiring measurements such as the annulus–to–coronary artery ostial distance. Iliofemoral arterial evaluation is also crucial to assess the intraluminal diameter, atherosclerotic burden, and vessel tortuosity to plan for device approach. We discuss techniques to optimize CT protocols using both electrocardiography-gated and nongated acquisitions, as well as the radiologist’s role in obtaining the necessary measurements and creating reformatted double oblique transverse images of the aortic annulus and adjacent structures. Appropriate reporting algorithms are also discussed.
Conclusion: TAVR is a complex procedure requiring the special skills of a multidisciplinary team including interventional cardiologists, cardiac surgeons, and radiologists. As this procedure is made increasingly available, the radiologist must master implementation and interpretation of preprocedural CT angiography scans, for which a sound understanding of the aortic root anatomy and pertinent reconstruction techniques is fundamental.