Bicuspid Aortic Valve Aneurysm
Congenitally abnormal aortic valves are defined morphologically according to the number and type of cusps and commissures. The bicuspid aortic valve, first recognized by Leonardo da Vinci in the early 16th century, is the most common congenital anomaly to which that structure is subject. The estimated incidence is 0.9% to 2% of the general population, or a prevalence in the United States of ≈4 million. Two varieties of bicuspid aortic valves are based on commissural fusion, namely, fusion between the left and right cusps or fusion between the right and noncoronary cusps. Three varieties of bicuspid aortic valves are based on cuspal size, namely, 2 cusps of equal size, 2 cusps of unequal size, or a conjoined cusp that is twice the size of its mate. The greatest degree of cuspal inequality is represented by the conjoined cusp. The images shown here represent a unique variety of cuspal inequality caused by aneurysmal dilatation of the nonconjoined cusp (Figure). Dilatation of the ascending aorta, which is a common coexisting feature of a bicuspid aortic valve, is caused by an inherent medial abnormality that attenuates the ascending aortic wall, and is coupled with the bicuspid morphology of the congenitally malformed valve rather than its functional state. The aneurysmal cusp shown in the Figure might harbor a tissue abnormality analogous to the inherent medial fault that attenuates the dilated ascending aorta.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.