Aortic Root Imaging in the Era of Transcatheter Aortic Valve Implantation/Transcatheter Aortic Valve Replacement

Abstract

b) defining the most appropriate valve size for the patient; and c) identifying the anatomic factors associated with complications. 5 Undoubtedly, one of the most important tasks to be carried out before placement of a percutaneous aortic valve is accurate determination of the diameter of the aortic annulus. The aortic annulus is the base of the aortic root; it represents a transitional area between the left ventricular outflow tract and the aorta and, moreover, is the structure in which the valve is secured. In most patients, it has an elliptical shape, and 2-dimensional imaging techniques such as echocardiography or angiography usually underestimate its true dimensions as they measure the diameter in a single plane. In the measurement of the aortic annulus, MDCT and magnetic resonance imaging offer greater accuracy as they enable 3-dimensional evaluation of it size, allowing measurement of the largest and smallest diameters, the true area of the annulus, and the diameter derived from the measurement of the area. The sizing of the aortic annulus with these 2 methods exhibits low intraobserver and interobserver variability, which is important since the accuracy of these measurements improves selection of the proper diameter