CT in transcatheter aortic valve replacement.

Transcatheter aortic valve replacement is a new method to treat patients with symptomatic, severe aortic stenosis who are at high surgical risk. Short- and midterm results have been encouraging, with more than 90,000 procedures performed worldwide. Patient selection, prosthesis sizing, and access strategies heavily rely on noninvasive imaging. Computed tomographic (CT) angiography is increasingly used for peri-interventional evaluation, as this modality allows for objective three-dimensional assessment of the aortic root, evaluation of the iliofemoral access route, and prediction of appropriate projection angles for prosthesis deployment. Compared with two-dimensional imaging techniques, CT provides comprehensive information about aortic annulus anatomy and geometry, supporting appropriate patient selection and prosthesis sizing. Recently, integration of CT measurements into sizing algorithms has been demonstrated to significantly reduce the incidence of paravalvular regurgitation, compared with prosthesis sizing with two-dimensional echocardiography. In addition, CT-based vascular access planning has been shown to reduce vascular access complications. Postprocedural CT imaging allows for the documentation of procedural success, evaluation of prosthesis positioning, and identification of asymptomatic complications. In this article, the rapidly emerging role of CT in the context of transcatheter aortic valve replacement will be described. Online supplemental material is available for this article. © RSNA, 2013.