Long-Term Outcomes of Mitral Valve Replacement in Patients Weighing Less Than 10 Kg

Abstract Background: The outcomes of mitral valve replacement (MVR) in pediatrics especially in the patients weighing less than 10kg are not always favorable. This study aimed to measure long-term outcomes of MVR in our institution.Methods: Nine young children weighing less than 10 kg underwent MVR with mechanical prostheses from November 2006 to April 2019 were enrolled in this retrospectively study. Kaplan–Meier survival analysis was used for the prediction of freedom from death and adverse events. Chi-square test was performed to compare outcomes for patients based on the ratio of mechanical prosthesis and weight. 14 related literatures were also reviewed to support our study.Results: All patients received bileaflet mechanical prostheses. The surgical technique varied among the patients with prostheses implanted in the intra-annular (n = 5), supra-annular (n=1), or with a Dacron conduit segment in the supra-annular position(n = 3). The valve size/weight ratio ranged from 2.11 to 5.00. After a mean follow-up period of 80.67 ± 63.37 months, the survival rate was 66.67%. One (11.1%) patient underwent an immediate revision MVR after initial MVR for the periprosthetic leak. No patients required surgical reintervention for the development of left ventricular outflow tract obstruction or permanent pacemaker placement during long-term follow-up.Conclusions: The tailored surgical strategy utilized for MVR in infants resulted in reliable valve function and excellent survival. Although revision is inevitable due to somatic growth, the bileaflet mechanical prostheses displayed appropriate durability.