Systemic atrioventricular mechanical valve replacement (SAVR) in children is challenging particularly in the youngest because of poor long-term outcomes.

We reviewed the clinical and surgical records of 96 children who underwent SAVR procedures (n=110) in Necker hospital between 2000 and 2017. The median age and the median weight at first operation were respectively 3.1 years (range, 1 month to 17 y) and 11.4kg (range, 2.5 to 68kg). Twenty-six patients (31%) were<1-year-old. Median follow-up for operative survivors was 4.3 years (IQR 2.3–9.5 y, up to 17.5 y, 98% complete).

Global mortality was 18%. One-year, five-year and ten-year patient survival was respectively 87%, 82% and 78%. By multivariate analysis, high operative mortality in children<1-year-old with Shone's syndrome was the most important contributor to poor long-term survival (P=0.03). Among survivors, the 10-year freedom from reoperation was 74%. Five-year survival substantially increased in the second period of the study (70% before 2008 vs. 88% after 2008, P=0.03). From 2008, changing age-adjusted predictors of death were median valve size (23mm vs. 16mm, P=0.03) and the prosthesis design (40% inversed aortic prosthesis vs. 100% classic mitral prosthesis, P=0.002). Complications after SAVR included heart block requiring pacemaker (13%) with a higher risk in case of atrioventricular canal (P=0.004), bleeding (6%), prosthesis thrombosis (3.5%), stroke (2%) and endocarditis (5%).

Early mortality after SAVR decreased during the second period of our study. Modification of the operative technique was the main cause of better early outcomes. SAVR replacement remains a challenging procedure with high mortality but limited mortality related to anticoagulation.