We report the case of an infant operated on at 11 months, having been clinically, echocardiographically and hemodynamically diagnosed when 2 days at the age. In the Echo-Doppler study the visualisation of the tunnel and the presence of aortic regurgitation within it and in the left ventricular outflow tract confirmed the diagnosis. Surgical access to both orifices, aortic and left ventricular, through the tunnel (after incision in the same) allowed it to be closed with two Goretex patches from its external face. This technique has a double advantage: a) it avoids annular distortions or aortic valvular lesions, b) excluding the tunnel (partial resection of edges and subsequent continuous suture) any possibility of subpulmonary stenosis through compression is eradicated.