Neo-aortic root dilation and valve regurgitation up to 21 years after staged reconstruction for hypoplastic left heart syndrome

Objectives We sought to assess the prevalence and progression of neo-aortic root dilation and valvar regurgitation after staged reconstruction for hypoplastic left heart syndrome (HLHS). Background In HLHS, the pulmonary valve functions as the neo-aortic valve. Neo-aortic valve dysfunction has been observed after arterial switch operation and the Ross procedure. Methods Patients with HLHS born before January 1995 who had the Fontan operation and had serial echocardiograms were included. Echocardiograms were reviewed preoperatively, after each surgical reconstruction, and at most recent follow-up for neo-aortic root size and severity of neo-aortic regurgitation (AR). Potential risk factors for neo-aortic valve dysfunction were assessed. Results Fifty-three patients met inclusion criteria. Bidirectional superior cavopulmonary anastomosis as an interim procedure was performed in 39 patients (74%). Median duration of follow-up was 9.2 (range 5.1 to 21) years. During follow-up, the neo-aortic root progressively dilated out of proportion to body size over time, with 52 patients (98%) having a Z-score >2 at most recent follow-up. Neo-AR was present in 61% of patients at most recent follow-up, with progression over time in 26 patients (49%). However, neo-AR was more than mild in only three patients. Significantly larger neo-aortic root Z-scores were observed in patients with any degree of neo-AR at most recent follow-up. No other anatomic or clinical variables correlated with severity of neo-AR or root dilation. Conclusions After staged reconstruction for HLHS, neo-aortic root dilation and neo-AR progress over time. Early volume unloading does not have a beneficial impact on dilation of the neo-aortic root. These findings raise concerns about neo-aortic valve function into adulthood.