Systemic atrioventricular valve replacement by mechanical prosthesis in children: Evolution in practice and predictors of long-term outcome

Abstract

Systemic atrioventricular mechanical valve replacement (SAVR) in children is challenging particularly in the youngest because of poor long-term outcomes related to the fixed size of the prosthesis and the anticoagulation treatment. We reviewed the clinical and surgical records of 85 children who underwent SAVR at our institution 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 11.4 kg (range: 2.5 to 68 kg). 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%. No significant predictive factor was associated with operative mortality. Among survivors, the 10-year freedom from reoperation was 74%. Complications after SAVR included heart block requiring pacemaker (13%) with a higher risk in case of atrioventricular canal ( P = 0.004), bleeding (7%), prosthesis thrombosis (3.5%), stroke (2%) and endocarditis (5%). By multivariate age-adjusted analysis, the surgical strategies were the most important contributors to the long-term outcome. While undergoing a prosthesis implantation in supra-annular position was at high risk of late complications (OR = 1.6, P = 0.017), using an inversed aortic prosthesis prevented them (OR = −2.3, P = 0.004). SAVR replacement remains a challenging procedure with high mortality but limited mortality related to anticoagulation. Modifications of the operative technics are one of the major causes of better long-term outcome.