Neo-aortic valve regurgitation and root dilation after arterial switch operation in patients with native left ventricular outflow tract obstruction.

Objective: To assess risk factors for neo-aortic insufficiency (AI) after the arterial switch operation (ASO) or double-switch operation (DSO) for transposition of the great arteries (TGA) beyond the neonatal period. We hypothesized that native left ventricular outflow tract obstruction (nLVOTO) without prior pulmonary artery banding (PAB) increases the risk of neo-AI-related reoperation.

Methods: This retrospective review included 157 patients (excluding neonates) with D- or L-TGA who underwent ASO (n = 47) or DSO (n = 110) between 2011 and 2024. The primary endpoint was neo-AI-related reoperation, and risk factors were assessed.

Results: Fifteen patients required a neo-AI-related reoperation. Multivariable analysis identified nLVOTO without antecedent PAB as the sole risk factor for these reoperations. Freedom from neo-AI-related reoperation at 5 years was 59.1% in the nLVOTO group (n = 48) and 93.2% in the PAB group (n = 109) (P < .001). The change in neo-aortic root z-score (neoAoR-Z) following ASO was greater in the nLVOTO group compared to the PAB group (1.07 vs 0.16; P < .001). Among the 11 patients in the nLVOTO group requiring reoperation, 4 (36%) underwent the procedure before discharge. In patients with nLVOTO, freedom from neo-AI-related reoperation at 4 years was 79.5% for those with a prebypass neoAoR-Z ≤0, 72.7% in those with a prebypass neoAoR-Z >0 with root reduction, and 19.0% in those with a pre-bypass neoAoR-Z >0 without reduction (P = .008).

Conclusions: A rapid increase in the neoAoR-Z is associated with a higher incidence of neo-AI in the nLVOTO group compared to the PAB group. Simultaneous neo-aortic root reduction may mitigate this risk, warranting consideration of additional surgical strategies.