Elective Melody valve insertion in mitral position: What have we learnt from our first and successful case?

Abstract

Melody valve insertion in mitral position is no longer an experimental procedure and is now an acceptable option for severe mitral valve disease in infants and neonates. Although there are more and more publications outlining the outcome, our first and successful case taught us a couple of points that we would like to share. A 20 days-old baby with severe congenital mitral insufficiency underwent Melody valve implantation. The stent was fashioned to avoid left ventricular outflow tract obstruction and expanded with a 14 mm balloon. A small ASD was created to allow further percutaneous balloon dilation. The baby was discharged after 6 weeks and treated with antiplatelet therapy. Postoperative management consisted in close transthoracic echocardiographic follow-up. Two percutaneous balloon dilatations of the stent (14 and 16 mm) were performed, respectively 9 and 16 months after the initial surgery. The patient presented infective endocarditis (Haemophilus influenzae) 26 months after surgery. TTE showed moderate Melody valve regurgitation and stenosis (mean gradient: 11 mmHg) with post-capillary pulmonary hypertension. Mitral valve replacement was performed after 6 weeks of antibiotic therapy. The stent was explanted and a 19 mm mechanical prosthetic valve was inserted. Postoperative course was uneventful. Melody valve in mitral position is now an accepted option but morbidity and mortality remain significant. Post-implantation management is challenging and guidelines are missing. Percutaneous stent dilation, hybrid valve in valve implantation and mechanical mitral valve replacement are 3 possible options in case of valve dysfunction. The per-operative pictures ( Fig. 1 , Fig. 2 ) help to understand why, in our case, the first 2 options would have failed. Fig. 1 shows non-calcified and mobile leaflets. One leaflet had a small 2 mm perforation. The stent itself, in contrast, was so thickened that dilatation or valve in valve procedure would have failed at this stage. Major endothelialization of the stent might significantly limit post-implantation management options. We believe that heart teams have to be aware of this potential evolution of the stent in order to establish the best procedural strategy in these patients.