Bicuspid pulmonary valve in transposition of the great arteries: impact on outcome.

Objective: Long-term evaluation of the impact of bicuspid pulmonary valve on neoaortic valve regurgitation and aortic root dilatation (ARD) after arterial switch operation (ASO) for transposition of the great arteries (TGA).

Methods: Between January 1987 and March 2010, 980 neonates underwent ASO for TGA. A total of 40 patients (4.0%) had a pulmonary bicuspid valve with no significant left ventricular outflow tract obstruction. In this group, 11 patients (28%) had associated ventricular septal defect, three hypoplastic aortic arch, and three had a right ventricular hypoplasia. No pulmonary valvuloplasty was attempted. Mean follow-up was 7.7 ± 5.5 years. Echocardiography evaluations of neoaortic valve function and morphology and aortic root dimensions were performed.

Results: There were two hospital deaths (5%) related to hypoplastic right ventricle and left ventricular dysfunction, and no late death yielding an actuarial survival to 95% SD at 1, 5, and 10 years. At last follow-up, five patients (12%) had mild-to-moderate aortic regurgitation (AR). None had aortic valve stenosis. ARD was noted in 28% of the patients (Z-score up to +3). One patient needed a Bentall procedure for significant AR and severe dilatation of the ascending aorta at 11 years of age. As many as four patients underwent reoperation (10%) for stenosis of the left coronary artery. Freedom from reoperation was 95% SD, 88% SD, and 75% SD at 1,5, and 10 years, respectively.

Conclusions: ASO is a safe option for TGA associated with a well-functioning bicuspid pulmonary valve with low morbidity and mortality. Prevalence of AR was not particularly high. Even though ARD was frequent, neoaortic bicuspid valve did not represent a high risk for aortic reoperation. Long-term individual follow-up is mandatory to observe the potential risk of root dilatation and AR.