Pump size of Berlin Heart EXCOR pediatric device influences clinical outcome in children

Abstract

The pediatric Berlin Heart (BH) EXCOR device provides mechanical circulatory support as a bridge to transplantation or recovery in children. Despite the availability of various pump sizes, information on the impact of pump size on clinical outcome is still lacking. We aimed to evaluate whether pump size in relation to body surface area (BSA) has an impact on clinical outcome. Children requiring implantation of a BH between 2000 and 2013 were included in this retrospective study. Primary end-points were events leading to BH explantation (transplantation, recovery or death) and the secondary end-point was occurrence of thromboembolic events. Patients were categorized into three groups according to BH stroke volume per BSA: optimal (30 to 50 ml/m(2)); small (<30 ml/m(2)); and large (>50 ml/m(2)). Eighty children (median age 2.2 years, median BSA 0.50 m(2)) underwent BH implantation. Fifty-five (69%) children had an optimally sized pump implanted, whereas 8 children (10%) had small pump and 17 (21%) large pump implantation. Overall survival rate was 69%. Weaning was possible in 15 children (19%), and 39 children (49%) were transplanted. Mortality, myocardial recovery and transplantation were not related to age, BSA or pump size. Thromboembolic events occurred significantly more frequently in children treated with large pumps. The broad range of body sizes in children from newborns to adolescents requires a wide choice of appropriately sized devices. Large pump size in relation to BSA is an independent risk factor for occurrence of thromboembolic events.