Long-term outcome after annular mechanical mitral valve replacement in children aged less than five years

When mitral valve repair in children is not possible, mitral valve replacement (MVR) is an alternative, which could result in better outcomes. We report the long-term outcome after replacement of systemic atrioventricular valve with bileaflet mechanical valves in annular position in patients less than 5 years of age.

Between 1983 and 2008, 29 MVRs were performed in children aged 1.82 ± 1.34 years (range, 95 days to 4.6 years); the average weight was 8.06 ± 2.92 kg (range, 4.7 to 15 kg). The main indication (86%) was severe regurgitation. Prosthesis size ranged between 17 mm and 25 mm.

The follow-up was completed and totaled 373 patient-years (12.4 ± 8.6). Four children presented with permanent atrioventricular block. Freedom from thromboembolic and hemorrhage events at 1, 5, 15 years was 100%, 96.1%, and 91.3%, respectively. All deaths occurred within 2 months after MVR and were 5 children (17%). No late mortality was observed. Freedom of redo MVR at 5, 10, and 15 years was 95%, 86%, and 70%, respectively. At MVR, weight 7 kg or less and age 1 year or less (p = 0.03) were associated with redo MVR. During redo MVR, a larger mechanical valve was implanted (+2 sizes), with no postoperative death. Currently, 23 patients are in New York Heart Association class I, and 1 patient is in class II.

The results of mechanical annular MVR are acceptable in children. Anticoagulants are well tolerated, with little thromboembolic complication. Long-term results for patients who survive the hospital period are excellent, and reinterventions show safe results.