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

Long-term outcomes following mitral valve replacement in children at heart center Leipzig: a 20-year analysis

BACKGROUND

Although mitral valve repair is the preferred surgical strategy in children with mitral valve disease, there are cases of irreparable severe dysplastic valves that require mitral valve replacement. The aim of this study is to analyze long-term outcomes following mitral valve replacement in children in a tertiary referral center.

METHODS

A total of 41 consecutive patients underwent mitral valve replacement between February 2001 and February 2021. The study data was prospectively collected and retrospectively analyzed. Primary outcomes were in-hospital mortality, long-term survival, and long-term freedom from reoperation.

RESULTS

Median age at operation was 23 months (IQR 5-93), median weight was 11.3 kg (IQR 4.8-19.4 kg). One (2.4%) patient died within the first 30 postoperative days. In-hospital mortality was 4.9%. Four (9.8%) patients required re-exploration for bleeding, and 2 (4.9%) patients needed extracorporeal life support. Median follow-up was 11 years (IQR 11 months - 16 years). Long-term freedom from re-operation after 1, 5, 10 and 15 years was 97.1%, 93.7%, 61.8% and 42.5%, respectively. Long-term survival after 1, 5, 10 and 15 years was 89.9%, 87%, 87% and 80.8%, respectively.

CONCLUSION

If MV repair is not feasible, MV replacement offers a good surgical alternative for pediatric patients with MV disease. It provides good early- and long-term outcomes.

Predictors of Valve Failure Following Surgical Atrioventricular Valve Replacement with a Melody Valve in Infants and Children

Options for atrioventricular (AV) valve replacement in small pediatric patients are very limited. The Melody valve has shown reasonable short-term outcomes. This study was aimed at identifying predictors of valve failure following AV valve replacement with a Melody valve at a single-center. 26 patients underwent 37 AV valve replacements with 31/37 (84%) of valves placed in the systemic AV valve position. Median age at procedure was 17 months (IQR 4-33) and weight was 8.5 kg (IQR 6.25-12.85). Median balloon size for valve implant was 20 mm (IQR 18-22). Repeat intervention occurred in 21 cases (57%) with repeat surgery in all but one. Median freedom from re-intervention was 31 months; 19% were free from re-intervention at 60 months. Age < 12 months weight < 10 kg and BSA < 0.4 m2 were all significant risk factors for early valve failure (p = 0.003, p 0.017, p 0.025, respectively). Valve longevity was greatest with balloon inflation to diameter 1.20-1.35 times the patient's expected annular diameter (Z0), relative to both smaller or larger balloons (p = 0.038). In patients less than 12 months of age, patients with single ventricle physiology had an increased risk of early valve failure (p = 0.004).

Surgical Melody Mitral Valve: A Paradigm Shift for Infants With Unrepairable Mitral Valve Disease

BACKGROUND

The Melody valve (Medtronic, Minneapolis, MN) for mitral valve replacement (MVR) (MelodyMVR) has been an effective strategy to treat unrepairable mitral valve disease in small children. This study analyzed survival, durability, and complications of the MelodyMVR strategy.

METHODS

Patients who underwent MelodyMVR between 2014 and 2023 were included. Transplant-free survival was analyzed with Kaplan-Meier analysis. The Fine and Gray subdistribution method was applied to quantify the cumulative incidence.

RESULTS

Twenty-five patients underwent MelodyMVR. Median age and weight were 6.3 months (interquartile range, 4.4-15.2 months) and 6.36 kg (interquartile range, 4.41-7.57 kg). Fifteen patients (60%) had congenital mitral valve disease and 13 (52%) had dominant mitral regurgitation. The median diameter of the implanted Melody was 16 mm (interquartile range, 14-18 mm). Mortality at 6 months, 1 year, and 5 years was 8.3% (95% CI, 2.2%-29.4%), 12.5% (95% CI, 4.2%-33.9%), and 17.6% (95% CI, 7.0%-40.7%), respectively. Two hospital survivors (8%) required early Melody replacement. Competing risk analysis showed that ∼50% of patients underwent mechanical MVR by 3.5 years after MelodyMVR. Freedom from bleeding and thrombosis at 4 years was 87.5% (95% CI, 74.2%-100%). Eleven patients underwent subsequent mechanical MVR with no deaths. One (9%) required pacemaker implantation after mechanical MVR.

CONCLUSIONS

MelodyMVR provides reasonable early and medium-term survival in small children and a high rate of successful bridge to mechanical MVR. MelodyMVR is associated with minimal pacemaker requirement, bleeding, and thrombosis. Early Melody functional deterioration necessitates early repeat MVR, which can be achieved with minimal morbidity and mortality.

Surgical Mitral Valve Replacement Using a Catheter-Based MelodyTM Valve in a Landing Zone Constructed With a PTFE-Covered Expandable Cheatham-PlatinumTM Stent

Mitral valve replacement using a Melody valve is a promising solution to the challenge of surgical mitral valve replacement in infants with a hypoplastic annulus. We report the creation of a landing zone in the mitral valve annulus using a Cheatham-Platinum (CP)-covered stent that facilitates Melody valve placement, helps prevent paravalvular leak, minimizes left ventricular outflow tract obstruction, and allows for potential future dilation of the valve.

Infant Mitral Valve Replacement: Current State of the Art

Mitral valve replacement (MVR) in the very young is an imposing clinical challenge. Early and late mortality risk is substantial, severe adverse events are common, and redo mitral valve replacement is inevitable. Therapeutic options are limited. In the older infant with an annulus of 17mm or larger, mechanical MVR is associated with low risk of mortality and predictable durability. For the very young with annular hypoplasia, bovine jugular vein conduit MVR appears to offer equivalent or better early outcomes with the possibility of subsequent valve expansion, potentially prolonging the interval to redo MVR. Experience with cylinder MVR and other forms of surgeon-manufactured MVR is quite limited, and there is currently no information on late outcomes or durability.