Long-Term Outcomes After Arterial Switch Operation: Risk Factors and the Impact of Anatomical Complexity in a Single-Centre Cohort

The arterial switch operation (ASO) is the standard surgical intervention to correct transposition of the great arteries (TGA). The aim of this study is to describe long-term outcomes after the ASO in patients with TGA, and to explore anatomical and clinical factors potentially associated with adverse outcomes, comparing simple and complex TGA. Since December 2001 to October 2023, 233 patients underwent arterial switch operation (158 simple TGA and 75 complex TGA). Kaplan–Meier analysis assessed survival and reoperation risk, Chi-square test and T-student test have been performed in order to analyse pre-, intra- and post-operative data among the two groups. In-hospital mortality was 1.7%. Overall survival rates were 97.9%, 96.8% and 96.8% at 5, 10 and 15 years, respectively. Freedom from surgical reoperation at 15 years was 98.3% in simple TGA and 91% in complex TGA at 15 years (p = 0.039). Reinterventions were infrequent and mainly related to pacemaker implantation and right ventricular outflow tract obstruction. Coronary artery stenosis occurred in 5 patients (2.2%). Risk factors analysis suggested that anatomical complexity such as intramural coronary artery (p = 0.003), aortic arch hypoplasia (p = 0.004), aortic arch interruption (p = < 0.001) and coronary reimplantation with button technique (p = 0.018) are predictive factors for mortality. In addition, complex TGA (p = 0.022) and post-operative aortic regurgitation (p < 0.001) are identified as potential predictive factors for reintervention. Arterial switch operation provides excellent long-term survival and low reintervention rates in TGA. These results support tailored long-term surveillance, particularly for patients with complex anatomy or coronary anomalies.