Novel Modifications of a Ventricular Assist Device for Infants and Children

Abstract

A continuous-flow "adult" ventricular assist device (VAD) was modified to support infants and children waiting for heart transplantation. A centrifugal VAD, designed to flow at 1.5 to 8 L/min, was used as a bridge to transplantation in pediatric patients. In smaller children and infants, a modified recirculation shunt permitted lower flow ranges. In hypoxic patients, an oxygenator was spliced into the circuit. From 2010 to 2015, the VAD was placed in 13 consecutive patients. Age ranged from 0.9 to 16 years (median, 7 years). Body surface area (BSA) ranged from 0.4 to 2.1 m(2) (median, 0.8 m(2)). Ten patients had a BSA less than 1.0 m(2). Four patients were receiving extracorporeal membrane oxygenation (ECMO) before VAD. Three patients had single-ventricle physiology. Five patients hada recirculation shunt and 3 underwent insertion of an oxygenator. Median time on the VAD was 20 days (range, 2-140 days). In patients with a recirculation shunt, mean patient flow was 1.5 L/min (mean flow/BSA, 2.7 L/min/m(2)), with mean total VAD flow of 3.4 L/min. Twelve patients underwent transplantation, and 1 patient underwent VAD explantation. All patients survived and were discharged at a median of 26 days (range, 17-83 days) after transplantation. Three patients experienced major bleeding events. There were 2 cerebrovascular accidents. VAD mortality dropped from 33% (3 of 9) during 2007 to 2010 to 0% (0 of 13) between 2011 and 2015 (p= 0.05). Wait-list mortality dropped from 10% (5 of 52) to 4% (4 of 91) for these periods (p= 0.29). The centrifugal VAD successfully supported pediatric patients awaiting heart transplantation. The modified recirculation shunt facilitated the successful support of patients in whom optimal flows were substantially lower than those recommended by the manufacturer. The design allows placement of an in-line oxygenator. Compared with pulsatile devices, use of this VAD was associated with a trend toward decreased mortality associated with VAD use.