[Balloon dilatation of subvalvular membranous stenosis of the aorta in an 8-year-old boy].

Case-history of an eight-year-old boy with subvalvular membranous aortal stenosis where the authors used for treatment percutaneous dilatation by means of a balloon catheter without using surgery. The authors recommend to eliminate the stenosis as soon as possible before serious aortal insufficiency develops.