Long-term outcomes of the arterial switch operation for transposition of the great arteries and ventricular septal defect and/or aortic arch obstruction

Objectives: Long-term outcomes after the arterial switch operation (ASO) for complex transposition of the great arteries (TGA) should be clarified.

Methods: A retrospective study was conducted in patients operated on between 1982 and 1998. Overall 220 postoperative survivors, 79.1% with a ventricular septal defect, 13.2% with multiple ventricular septal defects, and 29.1% with aortic arch obstruction, were followed for 17 years (0-28 years).

Results: The conditional survival rate was 96.7% [95% confidence interval (CI): 94.4-99.1] at 25 years. Late sudden death occurred in 2 asymptomatic patients. The cumulative incidence rate of death or reinterventions was 3.8% (95% CI: 2.9-4.8) at 25 years, with age at ASO <10 days and aortic regurgitation at discharge identified as independent risk factors. The cumulative incidence rate of neoaortic regurgitation was 41.6% (95% CI: 20.5-62.8) at 25 years with an aorto-pulmonary diameter mismatch at the time of the ASO, age at ASO <10 days and aortic regurgitation at discharge identified as independent risk factors. At the last follow-up, 53 patients (24.1%) had neoaortic root dilatation with an aortic sinus z-score ≥3 and 6 of them had a Bentall operation at a median delay of 14.1 years since the ASO. The only independent factors for neoaortic root dilatation were male sex and an aorto-pulmonary diameter mismatch at the time of the ASO.

Conclusions: Despite a continual rate of reinterventions, long-term survival and cardiovascular outcome are excellent after ASO for complex TGA. Dilatation of the neoaortic root and neoaortic regurgitation may be observed with time and 2 late sudden deaths occurred, justifying a close follow-up in all patients.