Background: Through restoring ventriculo-arterial concordance the arterial switch operation (ASO) is the preferred treatment of transposition of the great arteries (TGA). Besides coronary problems, there are some concerns about the fate of the neo-arterial trunks.
Patients and Methods: Since 1993, 99 neonates underwent ASO. 69 patients presented with simple TGA (mean age 8,2 d) and 30 patients had TGA with VSD (mean age 13,3 d). Aortic coarctation or interruption was associated in 10 patients. Late follow-up was focused on the assessment of the reconstructed neo-aortic and neo-pulmonary root after ASO.
Results: Operative mortality was 6 %. Follow-up included 93 patients over a mean period of 4,9 years (range 6 m – 13 y). Aortic regurgitation (AR) ≥ grade 2 was observed in 13 patients (13,9 %) and was progressive in 6 patients. Significant risk factors for AR were the presence of a VSD (p = 0,03) and pulmonary to aortic anulus diameter rate > 1,5 (p = 0,01), but not the technique of coronary transfer (p = 0,07) nor the access for VSD closure (p = 0,8). Minor residual LVOTO was measured in 6 patients. Only 1 child required late surgery for combined supravalvular aortic stenosis and AR grade 3.
Concerning the RVOT, increased flow velocity was observed in 47,3 %, located at the pulmonary bifurcation or pulmonary branch in 70 %. The gradient exceeded 30 mm Hg in only 3 patients, resulting in 1 reoperation for significant supravalvular RVOTO. In 4 patients recoarctation after aortic arch repair needed angioplasty.
Conclusion: After ASO, the neo-aortic root is larger than normal and may induce progressively significant aortic regurgitation in patients with severe aortic – pulmonary anulus discrepancy. Especially TGA variants with VSD need serial surveillance for neo-aortic root dilation. The reconstruction of the RVOT induces no significant late problems.