Current Risk Factors and Outcomes for the Arterial Switch Operation

Abstract

The arterial switch operation is the preferred treatment for dextrotransposition of the great arteries and some forms of double-outlet right ventricle. All patients undergoing an arterial switch operation at a single institution from January 1, 1999, to September 1, 2005, were reviewed. Of the 168 patients, median age was 2 days (range, 0 to 358) and weight was 3.5 kg (range, 1.9 to 11.8 kg). Eleven patients were less than 36 weeks gestational age. Forty percent had coronary patterns other than usual. Mean cardiopulmonary bypass (CPB) time was 147 +/- 45 minutes, and mean cross-clamp time was 77 +/- 27 minutes. At a mean follow-up of 19 +/- 21 months, there were 10 (6%) hospital and 4 (3%) late deaths. Actuarial 1-month, 1-year, and 3-year survivals were 94%, 90%, and 89%, respectively. Bivariate analysis revealed weight less than 2.5 kg (p = 0.032), gestational age less than 36 weeks (p = 0.002), and CPB time greater than 150 minutes (p = 0.0075) decreased hospital survival. Intermediate-term survival was negatively impacted by weight less than 2.5 kg (p = 0.017), gestational age less than 36 weeks (p = 0.0096), CPB time greater than 150 minutes (p = 0.0050), and age at presentation greater than 4 weeks (p = 0.034). By multivariate analysis, gestational age less than 36 weeks (p = 0.0051) and CPB time greater than 150 minutes (p = 0.016) were independent risk factors for hospital mortality. Gestational age less than 36 weeks (p = 0.0096) and CPB time greater than 150 minutes (p = 0.005) were also independent predictors of intermediate-term mortality. Coronary anatomy could not be shown to affect survival, including no deaths among the 12 patients with intramural coronaries. The arterial switch operation can be performed with low mortality regardless of diagnosis or coronary pattern. The premature patient and minimizing CPB time remain as challenges to optimize outcomes for the arterial switch operation.