[Aortic Valve Replacement of Quadricuspid Valve with Regurgitation].

Congenital quadricuspid aortic valve is a very rare malformation. In most cases it has been found incidentally at aortic valve surgery or at autopsy. It frequently causes aortic regurgitation, which may become manifest in adulthood and require surgical treatment. We reported 4 cases of aortic regurgitation with quadricuspid aortic valve. In all cases, aortic valve replacement was preformed with prosthetic valve, and their postoperative courses were uneventful. Two were Hurwitz's classification type b, one was type a and the last patient was type c. Although quadricuspid aortic valve is a rare anomaly, its potential for severe valve failure in adulthood should be kept in mind.