Thirty-year experience with the arterial switch operation.

BACKGROUND: We evaluated the results of the arterial switch operation (ASO) being performed at our institution for more than 30 years and identified risk factors for mortality and reoperation.

METHODS: Clinical outcome of 332 consecutive patients with transposition of the great arteries undergoing ASO was retrospectively analyzed, using surgical reports, medical charts, and latest follow-up echocardiography. Statistical analysis was performed using the Kaplan-Meier method and univariable and multivariable binary logistic and Cox regression analyses.

RESULTS: In-hospital mortality was 11.4%. At 15 years, estimated overall survival was 85.2%, and estimated freedom from reoperation was 74.0%. Cross-clamp time (p=0.001) and absence of the Lecompte maneuver (p=0.001) were identified as independent risk factors for in-hospital mortality, whereas coronary problems during surgery (p=0.009) and postoperative pacemaker implantation (p<0.001) were independent risk factors for late mortality. Independent risk factors for reoperation were higher age at the time of the ASO (p=0.002), presence of arch abnormalities (p<0.001), coronary problems during surgery (p=0.005), and duration of ventilation (p<0.001). At latest echocardiography, moderate or severe neoaortic regurgitation was present in 3.4% of the patients.

CONCLUSIONS: Overall, 30 years of experience with the ASO shows good survival and event-free survival rates. Coronary transfer problems during surgery were found to be an important risk factor for late mortality and reoperation. However, coronary anatomy other than 1LCx-2R and an intramural course of the left coronary artery or left anterior descending artery were not risk factors for mortality or reoperation. Neoaortic regurgitation does not seem to form a major problem.