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[Isolated aortic valve regurgitation due to degeneration of the valve leaflet--a clinical study].

From 1989 through 1993 thirty-eight patients underwent aortic valve replacement at our institution for isolated aortic regurgitation (AR) caused by idiopathic degeneration of the valve. There were 32 male and 6 female patients aged between 33 and 74 years with a mean of 59 years. Preoperative New York Heart Association functional class, cardiothoracic ratio, cardiac index, and left ventricular end-diastolic pressure were 2.6, 57%, 3.1 L/min/m2, and 18 mmHg, respectively. Cross-sectional echocardiography clarified aortic valve prolapse in seven patients. Excised valvular cusps were thin, redundant and translucent in association with cuspal fenestration in 9 cases and idiopathic commissural disruption in 2 cases. Histological study revealed significant disruption of the fibrosa and cystic degeneration of the spongiosa layer filled with mucopolysaccharide. Actuarial survival rate, including 3 operative deaths, was 89% at 3 years after AVR with no apparent valve related complications. Idiopathic degeneration of the aortic valve is a common cause of AR, occurring in half of the surgically treated patients. We emphasize the importance of this lesion as a cause of AR.