Long-term outcomes of mitral valve replacement in patients weighing less than 10 kg

Abstract

Background: The techniques of mitral valve repair（MVP ) in children have been well established and provide acceptable long-term outcomes; certain pediatric patients require mitral valve replacement (MVR) after an unsuccessful MVP. The outcomes of MVR in pediatrict especially in the patients weighning are not always favorable. This study aimed to measure long-term outcomes of MVR at our institute.Methods: Nine young children weighing less than 10 kg underwent MVR from November 2006 to April 2019. Their mean age was 11.88 ± 11.29 months and mean body weight was 6.83 ± 2.56 kg at the time of initial MVR. Four patients (44.4%) had undergone at least one previous cardiac surgical procedure prior to MVR. Several surgical techniques were used to implant mechanical bileaflet prostheses.Results: All patients received bileaflet mechanical prostheses. The surgical technique varied among the patients with valves implanted intra-annularly (n = 5), supra-annularly (n=1), or supra-annularly with a tilt (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 preprosthetic 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.