Early and midterm results of the arterial switch operation for transposition of the great arteries in Japan.

A total of 267 infants and children who underwent the arterial switch operation for transposition of the great arteries in the 6 years before Jan. 1, 1988 in six main Japanese institutions were entered into this review. The current status of patients surviving more than 1 year after the operation were evaluated along with early operative results. One hundred forty-six patients had an intact ventricular septum, 103 had a significant ventricular septal defect, and 18 had so-called Taussig-Bing anomaly of the transposition type. Eighteen patients were less than 28 days of age, 73 were 1 to 5 months of age, and 176 were older than 6 months of age at the time of operation. The overall mortality rate was 35% in the first 3 years and 12% in the more recent 3 years. There was a significant difference between the overall mortality rate of primary and two-stage repair (22% versus 10%, p = 0.047) in patients with intact ventricular septum. The overall mortality rate in patients with type B or C coronary arteries of Yacoub, and Radley-Smith's classification was significantly higher than that of other types of arteries (86% versus 18%, p = 0.0001). A total of 156 patients survived more than 1 year after the operation, and 44 children (28%) were noted to have supravalvular pulmonary stenosis (greater than 20 mm Hg). This complication was more common in patients operated on in the newborn period. Trivial or mild aortic regurgitation was noted in 29 patients (19%) and was more common in patients with two-stage than with primary repair (24% versus 14%). Aortic regurgitation was significantly more prevalent in patients in whom coronary arteries were implanted into slits or U-shaped defects than in those whose arteries were implanted into punched-out holes made on the pulmonary root (28% versus 8%, p = 0.049). Normal sinus rhythm was present in 97% of 154 patients and left ventricular ejection fraction was within the normal range in 97% of 115 patients at catheterization 1 to 5 months after the operation.