Which of the following statements about supravalvular aortic stenosis are true?

C. The diffuse form of supravalvular aortic stenosis may cause obstruction to branches of the aortic arch.

D. Reoperation after repair of discrete supravalvular aortic stenosis is rare unless abnormalities of the valve itself also exist.

DISCUSSION: Supravalvular aortic stenosis is a progressive disease and should be repaired surgically if symptoms are present or the systolic gradient exceeds 50 mm. Hg. In addition to excision of the supravalvular membrane, a patch of dacron or pericardium must be placed across the area of narrowing and down into at least one of the sinuses of Valsalva. Reoperation is rare after this procedure unless associated aortic valve disease is also present. In the diffuse form of the disease the thickening of the aortic wall commonly results in significant luminal narrowing of the ascending aorta and its major branches.