[Two cases of Konno's operation for aortic stenosis developing after repair of interruption of the aortic arch with ventricular septal defect]

Two patients, 8-year-old and 7-year-old boys, underwent Konno's operation for left ventricular outflow tract obstruction, which had developed after the repair of interrupted aortic arch and ventricular septal defect. Both cases had bicuspid aortic valve and severe subaortic stenosis. The annular diameters were 15 mm and 16 mm, and pressure gradients between the left ventricle and the ascending aorta were 110 mmHg and 105 mmHg, respectively. A SJM prosthetic valve (23 mm, 25 mm) was used. Postoperative courses were good. Left ventricular outflow anomalies are frequently found in cases of interrupted aortic arch complicated with ventricular septal defect. The stenosis not infrequently develops and becomes apparent several years after primary or staged repair for interrupted arch with VSD as in the present cases. Therefore, careful observation should be carried out following the repair. Konno's operation can be safely performed for this lesion with low mortality and morbidity for valvular and subvalvular aortic stenosis even with small aortic ring.