Unusual Intramural Coronary Artery With Vertical Course Complicating an Arterial Switch Operation.

Intramural coronary arteries in patients with d-transposition of the great arteries (d-TGA) usually arise from the opposite sinus of Valsalva and traverse horizontally across the posterior/facing commissure before emerging externally from the appropriate sinus of Valsalva. Failure to make appropriate technical modifications during coronary transfer can result in an important risk of posttransfer ischemia. We report a case with an unusual course of an intramural left anterior descending (LAD) coronary artery in a patient with d-TGA, with origin at the mid ascending aorta and a vertical intramural course, increasing the susceptibility to injury during an arterial switch operation (ASO).