Transapical access for dilatation of a Melody valve in the mitral position using large balloons, in a small child: a case description with midterm follow-up and literature review

The surgical placement of the Melody®valve in the mitral position in infants and young children was first reported in 2012. Since then, there have only been a limited number of technically oriented reports describing catheter techniques to tackle valve-related issues such as valve adjustment for somatic growth or the management of haemodynamically significant paravalvar regurgitation. We present a case study where severe paravalvar leaks were tackled using a hybrid approach and large low-pressure balloons in a child who had previously undergone Melody® valve implantation in the mitral position. The technical outcome remains very good at 18 months follow-up and the patient remains symptom-free.

Melody valve to replace the mitral valve in small children: Lessons learned

Objective:

Infants requiring mitral valve replacement have few viable options. Recently, stented bovine jugular vein graft (Melody) has been surgically implanted in such cases. Herein, we report our experience, elaborating on evolution of implantation technique, pitfalls, as well as long-term outcome (including late dilatability).

Methods:

Seven Melody valves were implanted (2013–2019). The median patient age and weight were 6.7 (1.8–30.5) months and 5.8 (4.6–9.5) kg, respectively. The indications for implantation were mitral stenosis and/or regurgitation postatrioventricular septal defect (AVSD) repair (5), congenital mitral valve dysplasia (1), and Shone's complex (1). Operative technique involved shortening the valve and creating a neo-sewing ring at 2/3 (atrial)–1/3 (ventricular) junction. Implantation was followed by intraoperative balloon dilatation.

Results:

Five out of seven patients survived the perioperative period (one death due to technical failure and the other due to acute respiratory distress syndrome postcardiopulmonary bypass). Two out of five medium-term survivors got transplanted (1) or died due to acute myeloid leukemia (1). No valves were replaced. The mean echo gradient at discharge was a median 4 (2–6) mmHg. None of the patients showed left ventricular outflow tract or pulmonary venous obstruction. Two Melody valves were dilated late (5 months and 3 years postoperatively), resulting in decreasing mean gradients from 6 to 1 and from 17 to 4 mmHg. At last follow-up, surviving Melody had a mean gradient of 4 (1–9) mmHg.

Conclusions:

Mitral valve replacement with a Melody valve is feasible in infants, is reproducible, shows good immediate results, and offers the possibility of later dilatation. This technique offers a better solution compared to the existing alternatives for infants requiring a prosthetic mitral valve.