Transposition of the great arteries: correction with conversion from single to dual coronary artery system

We describe the case of a newborn child with D-transposition of the great arteries who was found to have an uncommon single-origin coronary artery system. Surgical correction by arterial switch was performed but resulted in tension of the left coronary branch, which prevented discontinuation of cardiopulmonary bypass. The problem was eventually resolved by conversion into a dual coronary artery system through direct implantation of the left coronary branch into the aorta. The patient remains well, free from ischemia and with a patent left coronary artery, 2 years after operation.