Long-term outcomes of the neoaorta after arterial switch operation for transposition of the great arteries

Background: After the arterial switch operation (ASO) for transposition of the great arteries (TGA), the native pulmonary root and valve function in the systemic position, and the long-term risk for neoaortic root dilation and valve regurgitation is currently undefined. The aim of this study was to determine the prevalence and progression of neoaortic root dilation and neoaortic valve regurgitation in patients with TGA repaired with the ASO.

Methods: Measurements of the neoaortic annulus, neoaortic root at the level of the sinuses of Valsalva, and the degree of neoaortic regurgitation were assessed by serial transthoracic echocardiograms on 124 patients with TGA at a median follow-up of 7.2 years (range, 1 to 23 years) after the ASO at our institution.

Results: Neoaortic root dilation with z scores of 2.5 or greater was identified in 66%, and the root diameter z score increased at an average rate of 0.08 per year over time after ASO. Freedom from neoaortic root dilation at 1, 5, 10, and 15 years after ASO was 84%, 67%, 47%, and 32%, respectively. Risk factors for root dilation include history of double-outlet right ventricle (p = 0.003), previous pulmonary artery banding (p = 0.01), and length of follow-up (p = 0.04). Neoaortic valve regurgitation of at least moderate degree was present in 14%. Neoaortic root dilation was a significant risk factor for neoaortic valve regurgitation (p < 0.0001). No patient required reintervention on the neoaorta or neoaortic valve during follow-up.

Conclusions: Progressive neoaortic root dilation is common in patients with TGA after the ASO. Continued surveillance of this population is required.