Outcomes of Supra-annular Mechanical Atrioventricular Valve Replacement with Polytetrafluoroethylene Graft in Infants and Children.

Despite improvements in valve repair techniques, conditions in which infants and children need for mechanical valve replacement (MVR) are still present. We analyzed supra-annular MVR outcomes in infants and children with small annulus and compared them with conventional annular MVR outcomes. Data were collected retrospectively from medical records of infants and children (weighing < 20 kg) who underwent atrioventricular valve replacement with mechanical valve in Seoul National University Children's Hospital between December 1984 and January 2019. We identified 8 patients (median age 20 months, median weight 10.2 kg) who underwent supra-annular MVR with polytetrafluoroethylene graft (supra-annular group). The patients were diagnosed with congenital mitral valve malformation (5 patients), complete atrioventricular septal defect (2 patients), and functional single ventricle (1 patient). The implanted mechanical valve size ranged from 16 to 23 mm. Thirty-three patients (median age 40 months, median weight 13 kg) underwent conventional annular MVR (annular group). The survival rate was not significantly different between the supra-annular and annular groups (75.0 vs 78.8%, P = 0.816). In patients with biventricular repair (7 patients with supra-annular MVR and 28 patients with annular MVR), mechanical valve-to-mitral valve annulus size ratio was higher in the supra-annular group than in the annular group (1.24 ± 0.30 vs 0.96 ± 0.22, P = 0.035). No coronary complication or heart block were observed in the supra-annular group. Supra-annular MVR with polytetrafluoroethylene graft may be a feasible surgical option in children with a small annulus when valve repair is unsuccessful.