The size of the coronary arteries parallels the ventricular mass, thus it may be abnormal in complete transposition beyond infancy and could be influenced by the arterial switch operation. To investigate this possibility, we measured the diameters of the right, left main trunk, anterior descending, and circumflex coronary arteries before and three to seven years (mean 4.8) after the arterial switch operation in 17 patients with a “normal” distribution of the coronary arteries (so-called Shaher type 1). The values were compared with 18 controls who had Kawasaki disease with no apparent coronary arterial disease. The right, left anterior descending, and circumflex arteries were smaller than control values before the operation. The post-/preoperative ratios of the diameter were 1.16±0.11 for the right coronary artery, 1.18±0.16 for the left main trunk, 1.20±0.18 for the left anterior descending artery, and 1.22±0.26 for the circumflex artery. There were no significant differences among these values. After surgery, the right coronary artery was larger, but the left coronary arteries were smaller in the patients than in the controls: 2.5±0.3 vs 2.0±0.2 mm for the right coronary artery; 2.4±0.3 vs 2.7±0.1 mm for the left main trunk; 1.9±0.2 vs 2.4±0.2 mm for the left anterior descending artery; 1.6±0.4 vs 2.2±0.5 mm for the circumflex artery, respectively. The posterior descending coronary artery originated from the right coronary artery in all patients. The total cross-sectional area of the right coronary, left anterior descending, and circumflex arteries was 9.7±2.4 mm2 in the patients, and 11.8±2.9 mm2 in the controls (p>O. 1), suggesting that the increased size of the right coronary artery compensates for the small left coronary arteries. We conclude that the arterial system in complete transposition, with a large right coronary artery and small left coronary system, remains smaller than normal even at midterm follow-up after anatomic repair despite normalization of left ventricular volume and muscle mass.

An 11-month-old infant had undergone a primary arterial switch operation, including the Lecompte maneuver, for correction of discordant ventriculo-arterial connections and closure of an accompanying ventricular septal defect.

At discharge, there were no signs of aortic valvar incompetence. Regurgitation across the aortic valve was detected first at the age of 2 years, and then increased progressively, as documented by serial echocardiographic studies. There had been no history of bacterial endocarditis. At the age of 10 years, echocardiography revealed severe aortic valvar incompetence. At operation, the aortic valve had three leaflets, all of which were short, with very restricted movement. Absence of sufficient leaflet tissue precluded a durable valvar reconstruction, so the aortic valve was replaced with a 21 mm mechanical prosthesis. Histological examination of the removed leaflets revealed nodular swelling due to mucous changes of the matrix, as well as fibrous alteration and formation of scar tissue, including areas of fibroblastic and capillary proliferation. There were no signs of calcification or acute inflammatory changes. Improvement of left ventricular function was observed both early postoperatively and later on. Our observation shows that aortic valvar incompetence after an arterial switch operation can be caused by degenerative changes of the neo-aortic leaflets, which prevent plastic reconstruction of the valve, necessitating valvar replacement.