Fate of intramural coronary arteries after arterial switch operation

To evaluate the impact of intramural coronary arteries for the peri-, postoperative and long-term course after arterial switch operation (ASO).

ASO was performed in 351 patients between 1981 and 2000 with dextrotransposition of the great arteries (d-TGA). Five patients (1.4 %) had an intramural coronary artery. Coronary transfer was performed with a collar under dissection of the commissure without longitudinal splitting of the intramural section.

None of these patients died; the intraoperative course was uneventful, and no myocardial ischemic changes were observed. In three patients, follow-up cardiac catheterization after 5, 16 and 53 months revealed an occlusion of the intramural coronary ostium. Exercise electrocardiography and myocardial scintiscan showed myocardial ischemia. Two of these patients underwent a successful internal mammary artery bypass.

The intramural course of coronary arteries in patients with d-TGA is rare and does not cause increased mortality or myocardial infarction rates. However, the risk of coronary occlusion over time seems to be high. Therefore, patients with this condition require selective coronary angiography and frequent exercise investigations. Revascularization with an internal mammary artery bypass may be indicated.