Congenital quadricuspid aortic valve: report of nine surgical cases.

We report the clinicopathologic characteristics of the congenital quadricuspid aortic valve necessitating surgery. Among 616 patients for whom we performed an aortic valve operation over the past 20 years, nine patients (1.46%) (five men and four women, mean age 60 years) with quadricuspid aortic valve were encountered. All had aortic regurgitation (AR) except one with aortic stenosis and mild regurgitation (ASr). All were free of cardiac anomaly including that of the coronary arterial system. Macroscopically, severe calcification of the valve was seen in the one case of ASr. Fenestration of the cusp was seen in five cases of AR. Infective endocarditis was not seen. Histological study disclosed fibrous thickening and myxoid degeneration in the AR cases. In accordance with the Hurwitz and Roberts classification, four valves were type b (three equal-sized cusps and one smaller cusp), two valves were type a (four equal-sized cusps), two valves were type d (one large, two intermediate, and one small cusp), and one valve was type g (four unequal-sized cusps). Valve repair failed in one patient and was converted to valve replacement during the operation. All patients underwent successful aortic valve replacement (AVR).