[New technique for enlargement of the pulmonary outflow tract in corrected transposition of the great arteries [SLL]--a report of 2 cases].

New technique for enlargement of the pulmonary outflow tract was performed in two patients with corrected transposition of the great arteries [SLL] associated with atrial septal defect, ventricular septal defect, pulmonary stenosis and mitral regurgitation. The middle of the anterior leaflet of the mitral valve was incised to the valve annulus towards the mid-point of the mitral-pulmonary fibrous continuity. In this approach, anterior node and anterior atrioventricular conduction bundle were securely protected from the surgical incision. The pulmonary annulus was divided posterolaterally and the incision was further extended into the pulmonary trunk to the bifurcation. The pulmonary trunk was enlarged with a fusiform patch of the xenogenous pericardium bearing monocusp. In case 1, St. Jude Medical valve #31 was implanted in the mitral position. In case 2, mitral valvular annuloplasty with Carpentier ring #36 which was deformed to admit enlarged portion of the pulmonary trunk. The VSD was closed through the right atrium, placing the suture on the left side of the septum. However, complete A-V block ensured temporarily due to retraction at the operation in case 1. No conduction disturbance ensured in case 2. This technique can provide some advantage in avoidance of injuries to the anterior node and the anterior atrioventricular conduction bundle. Application of this technique to the corrected transposition of the great arteries without mitral regurgitation is to be further evaluated.