The Significance of the Interleaflet Triangles in Determining the Morphology of Congenitally Abnormal Aortic Valves: Implications for Noninvasive Imaging and Surgical Management

A comprehensive understanding of the normal and abnormal aortic root is paramount if we are to improve not only our assessment of the aortic root and its components but also the surgical approach to reconstructing this complex structure when congenitally malformed. Most anatomic and imaging-based classifications of the normal root recognize and describe the basic components, which include the shape and size of the three aortic sinuses and their three valvar leaflets, as well as the sinutubular junction and proximal ascending aorta. However, the three interposing fibrous interleaflet triangles, which share an intimate relationship with all elements of the root, are often ignored. In consequence, the important role the interleaflet triangles play in determining the function of the normal and congenitally malformed aortic root is underappreciated. Additionally, the subtle asymmetries found in the normal aortic root, such as differences between the sizes of the described components, underlie its hemodynamic efficiency. In this review the authors describe the complex structure of the normal aortic root, contrasting these normal characteristics with those found in the unicuspid and bicuspid variants of congenitally malformed aortic valves. Many of these features are readily recognizable using current imaging modalities and so should become a standard part of the description of aortic valvar disease. The authors believe that this thorough morphologic approach will provide a framework for the re-creation of a more normal aortic root at the time of repair or replacement, thereby improving current outcomes.