Aortic stenosis (AS)

Aortic stenosis is described as valvular, subvalvular or supravalvular, depending on its location.

Valvular aortic stenosis is due to fusion of one to all three commissures. The condition ranges from a slightly obstructive bicuspid aortic valve to high-grade critical aortic stenosis of the newborn. The valve tissue is usually thickened and myxomatous.

Surgery is indicated if symptoms are present or, in the absence of symptoms, above a pressure gradient of 50 mmHg at rest or an aortic valve opening area of 0.5 to 0.7 mm². The operation is performed using extracorporeal circulation and consists of commissurotomy or valvotomy under vision.

In extreme cases, heart valve replacement may be necessary. The Ross operation is particularly important in childhood and adolescence. In this operation, which is also called pulmonary autograft, the autologous pulmonary valve is resected and implanted in aortic position and the pulmonary valve is replaced by an appropriate homograft or sometimes by a biological prosthetic heart valve. The advantage of this operation, which is not entirely without risk, is that the aortic valve has a certain tendency to growth and lifelong anticoagulation is avoided. Various authors have reported excellent long-term results in individual cases.

In subvalvular aortic stenosis, there is a ring-shaped endocardial band. The indication for surgery is the same as in the case of valvular aortic stenosis. The operation, using the heart-lung machine, consists of resection of the fibrous tissue through the aortic valve.

The relatively rare supravalvular aortic stenosis can be corrected by widening the aorta with a homo­graft or Gore-Tex® patch.