Pathology of the diffuse variant of supravalvar aortic stenosis.

Supravalvar aortic stenosis is a rare congenital heart anomaly, producing left ventricular outflow tract obstruction. Of the two anatomic variants that have been described, diffuse type is the rarest. We report five such cases in children between two months and nine years of age. None had features of Williams syndrome. The entire aorta was involved in three cases, with abdominal aortic coarctation in two cases. Stenosis was mainly due to involvement of the media, which showed smooth muscle hypertrophy, abnormal elastic fibers, and mild collagenization. Predominant intimal change was seen in one case. Pulmonary, coronary, arch, renal, and common iliac arteries were also involved.