Mid- and Long-Term Follow-up after Percutaneous Pulmonary Valve Implantation in Children with the Melody Transcatheter Pulmonary Valve System

Objectives: While percutaneous pulmonary valve replacement using the Melody percutaneous pulmonary valve (PPVR) has been established as the treatment of choice for grownups with conduit and/or valve dysfunction in the pulmonary position, outcome after implantation in a growing population of children and adolescents is still under investigation. We aimed to examine the mid- and long-term outcome after PPVR in children and adolescents, focusing on valve functioning and integrity, necessity of reinterventions and incidence of endocarditis.

Methods: Fifty-seven children and adolescents aged 4 to 17 years (mean: 10.2 ± 3.4 years, weight 36.1 kg, height 140.3 cm) treated by PPVR using the Melody valve between March 2007 and July 2018 were enrolled in the study. The cohort was divided into three groups according to the primary hemodynamic lesion: A: pulmonary stenosis (n = 34), B: pulmonary regurgitation (n = 10), C: mixed lesion of stenosis and regurgitation (n = 13). Medical data including definition of the heart disease, invasive hemodynamic and echocardiographic data during follow-up were analyzed.

Result: At implantation, a mean diameter of the Melody valve of 20.7 mm (±2.5) was achieved in the study population. During mean follow-up of 51.3 months (±35.6) the study population showed a weight gain of 50.4% (36.1 vs. 54.3 kg) and height gain of 12% (140.3 vs. 157 cm). We found sustained hemodynamic improvements concerning pulmonary stenosis in groups A and C (A: 23.5–28.4 mm Hg, p = 0.92, C: 25.8–30.5 mm Hg, p = 0.63) and concerning regurgitation in group B (mild or no regurgitation in 80%). Freedom of reintervention was 82.1%, of endocarditis 92.6% and of stent fracture 96.4% at 8 years follow-up, with all these incidences being linked to patients with primary, residual or developing stenosis (group A and C only) in the right ventricular outflow tract (RVOT).

Conclusion: Despite relevant somatic growth, PPVR with the Melody valve shows favorable mid- and long-term results in children and adolescents. Reintervention and complication rate is low at 8 years of follow-up, and associated to residual or developing stenosis. Our findings suggest that the reduction of residual RVOT gradients e.g., by adequate prestenting and extension of the valve diameter during valve implantation has a significant impact on the persistence of positive hemodynamic parameters and therefore reduces the necessity for reinterventions and the risk complications.

Publication History

Article published online:
19 February 2021