Mechanical Assist Device as a Bridge to Heart Transplantation in Children Less Than 10 Kilograms

Abstract

Despite the remarkable advances with the use of ventricular assist devices (VAD) in adults, pneumatic pulsatile support in children is still limited. We report a retrospective review of our experience in very small children (<10 kg of body weight). Ten consecutive children weighing less than 10 kg were offered mechanical support with Berlin Heart (Berlin Heart AG, Berlin, Germany) as a bridge to heart transplant from March 2002 to March 2010. The median patient age was 10.4 months (38 days to 2.2 years). The median patient weight was 6.4 kg (2.9 to 10 kg). Prior to VAD implantation, all children were managed by multiple intravenous inotropes and mechanical ventilation (8) or extracorporeal membrane oxygenation (2). The median pre-VAD pulmonary vascular resistance index was 5.7 Woods units/m(2). Three patients required biventricular mechanical support, but in all other cases a single left VAD proved sufficient. The median duration of VAD support was 61 days (2 to 168 days). Four deaths occurred; from stroke in three and sepsis in one. Five patients were successfully bridged to heart transplantation after a median duration of mechanical support of 89 days (37 to 168 days) and another is still waiting a suitable organ after 77 days of VAD support. There were no complications related to postoperative bleeding. Five patients required at least one pump change. Of 5 patients undergoing heart transplant, 3 developed an extremely elevated (>60%) panel reactive antibody by enzyme-linked immunosorbent assay, confirmed by Luminex (Luminex Corp, Austin, TX). All 3 experienced at least one acute episode of rejection in the first month after heart transplant, needing plasmapheresis. The survival rate after heart transplantation was 100% with a median follow-up of 7.5 months. Mechanical support in very small children with end-stage heart failure is an effective strategy of bridge to heart transplantation with a reasonable mortality rate. The high rate of complications suggests to optimize indications and timing of VAD implantation.