Staged conversion to arterial switch for late failure of the systemic right ventricle

Abstract

Late failure of the systemic right ventricle is seen in up to 10% of patients after atrial switch for transposition of the great arteries and in patients with atrioventricular and ventriculoarterial discordance. Since 1981, 24 such patients have entered a program to achieve conversion to arterial switch. The primary diagnoses were transposition of the great arteries with ventricular septal defect (n = 10), transposition of the great arteries with intact ventricular septum (n = 5), Taussig-Bing anomaly (n = 4), and atrioventricular and ventriculoarterial discordance (n = 5). The mean interval from atrial switch to right ventricular failure was 7 years. Four patients underwent direct conversion to arterial switch, with one operative death. In 3 of these patients the initial left ventricular pressure was high. The fourth patient was too sick to undergo banding, and he required left ventricular assist device support after switch conversion. The other 20 patients underwent 34 procedures to place or tighten a pulmonary artery band to prepare the left ventricle to tolerate systemic pressure. There was one band-related operative death. Twelve patients have thus far gone on to switch conversion 13 days to 5 years (mean, 26 months) after banding. In total, therefore, 16 patients have had an arterial switch with atrial reconstruction. The early mortality for switch conversion was 2 of 16 (12.5%; 70% confidence limits, 4% and 27%), with one late death 12 months after operation. Including operative mortality, the 1-year actuarial survival probability after conversion was 80% (70% confidence limits, 62% and 92%). All survivors are asymptomatic. Two patients have required aortic valve replacement, and 5 others have mild aortic valve regurgitation after conversion. We conclude that this program of operation is a realistic alternative to cardiac transplantation, which would eventually be required for most of these patients. However, in our practice the two options are complementary, and transplantation can be offered (before or after banding) if arterial switch is not possible.