Mechanical Mitral Valve Replacements in the Pediatric Population

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.

Mitral valve replacement in children: balancing durability and risk with mechanical and bioprosthetic valves

OBJECTIVES

To investigate if there is still a place for bioprosthetic mitral valve replacement in children by comparing the prosthetic durability and transplant-free survival after bioprosthetic and mechanical mitral valve replacement.

METHODS

We reviewed all mitral valve replacements in children between 1981 and 2020. Bioprosthetic mitral valve replacement cases were individually matched to mechanical mitral valve replacement cases. The incidence rate of a 2nd replacement was calculated using the cumulative incidence function that considered death or transplantation as a competing risk.

RESULTS

The median age at implantation was 3.6 years (interquartile range 0.8-7.9) for the bioprosthetic valve cohort (n = 28) and 3 years (interquartile range 1.3-7.8) for the mechanical valve cohort (n = 28). Seven years after bioprosthetic mitral valve replacement, the cumulative incidence of death or transplantation was 17.9% [95% confidence interval (CI) 6.3-34.1] and the cumulative incidence of a 2nd replacement was 63.6% (95% CI 39.9-80.1). Seven years after mechanical mitral valve replacement, the cumulative incidence of death or transplantation was 28.6% (95% CI 13.3-46) and the cumulative incidence of a 2nd replacement was 10.7% (95% CI 2.6-25.5). Fifteen years after mechanical mitral valve replacement, the cumulative incidence of death or transplantation was 33.6% (95% CI 16.2-52.1) and the cumulative incidence of a 2nd replacement was 41.1% (95% CI 18.4-62.7). The cumulative incidence curves for bioprosthetic and mechanical mitral valve replacement were statistically different for a 2nd valve replacement (P < 0.001) but not for death or transplantation (P = 0.33).

CONCLUSIONS

There is no difference in transplant-free survival after bioprosthetic and mechanical mitral valve replacement in children. The lifespan of bioprosthetic mitral valves remains limited in children because of structural valve failure due to calcification. After 15 years, 40% of mechanical valves were replaced, primarily because of patient-prosthesis mismatch related to somatic growth.

The MITRIS RESILIA mitral valve is a safe and effective option for mitral valve replacement in young patients requiring mitral valve replacement

We report the first successful implantation in the United States of a novel mitral valve (MITRIS RESILIA by Edwards Lifesciences) in a patient with history of mitral valve replacement at a young age. This new bioprosthetic valve offers a unique profile and innovative option for mitral valve replacement in patients who are at risk of left ventricular outflow tract obstruction.

Modified atrioventricular valve replacement in children

One major challenge of atrioventricular valve replacement in children is the small size of the native valve annulus. In addition, in cases of atrioventricular septal defect, the atrioventricular node (AVN) shifts to a different location, making this condition difficult to treat. This report describes a technique that uses a trapezoid-shaped patch to separate the implanted valve suture-line from the AVN, which allows surgeons to implant larger valves while simultaneously preventing injury to the AVN.

Replacement of the Mitral Valve Under One Year of Age: Size Matters

Surgical management of mitral valve disease in neonates and infants is challenging. When repair is no longer feasible, replacement may become inevitable, but should only be considered as an option of last resort due to the remarkably high rate of associated morbidity and mortality. Mechanical valves are the preferred choice in large annuli, while stented conduits seem promising in smaller ones. In patients with a preoperative mitral valve annulus equal or larger than 15-16 mm, an intra-annular placement of the smallest mechanical valve available should be attempted. In patients with smaller annuli, the placement of a stented valved conduit seems to display a lower mortality risk. Supra-annular implantation of prostheses should be reserved for exceptional cases and to those familiar with this technique because of the high rate of associated complications.