Modified TandemHeart ventricular assist device for infant and pediatric circulatory support.

Abstract

The development of pediatric ventricular assist device (VAD) circuits with lower flow ranges for infants and small children is ongoing. We present our results with modifying a readily available adult VAD to support the pediatric population. The TandemHeart VAD (CardiacAssist, Pittsburgh, PA) circuit was modified to include a variable restrictive recirculation shunt to permit lower flow ranges in small pediatric patients. Initial benchtop flow rates and pressures were studied. Hemolysis trials were performed using whole bovine blood to compare plasma-free hemoglobin levels between modified and unmodified VAD circuits. The modified VAD was surgically implanted in 7 piglets (6 to 14 kg) and which supported them for 4 hours. Levels of hemolysis did not increase and full hemodynamic support was achieved. The modified TandemHeart VAD with a recirculation shunt was subsequently implanted in 2 pediatric patients who were bridged to transplant successfully. Because of its simplicity, availability, low prime volume, greater patient flow range, and lower cost, the modified TandemHeart VAD with a recirculation shunt should be considered as an alternative to extracorporeal membrane oxygenation and other pulsatile VADs in children.