Aortopulmonary window due to balloon angioplasty after arterial switch operation

We report 2 cases of aortopulmonary window that developed after balloon angioplasty for pulmonary artery stenosis. Both patients had undergone arterial switch operations for complete transposition of the great arteries before the angioplasty. These aortopulmonary windows were repaired through elective operations. The clinical features, diagnosis, management, and proposed mechanisms of this complication are described.