[Occlusion of left coronary ostium involving aortic stenosis and insufficiency].

Aortic valve replacement combined with enlargement of the valvar ring by the Nicks method and coronary artery bypass grafting via the left internal thoracic artery were performed for an 11-year-old girl with occlusion of the left coronary ostium. The left coronary sinus was covered with membranous tissue, so the left coronary ostium was not found. Aortic valve replacement with 21 mm prosthetic valve was possible by enlarging the valvar ring. The internal thoracic artery which is expected to grow with development of the body was used as the graft.