Enlarged and echogenic kidneys while on a pediatric ventricular assist device

Pediatric ventricular assist devices (VAD) specially designed for small children have been increasingly implanted in North America. We present unexpected renal findings developing in three children receiving circulatory support using VAD (EXCOR Pediatric Ventricular Assist Device; Berlin Heart Inc., The Woodlands, TX). The mechanisms of heart failure in these children included: 1) hypoplastic ventricle with aortic stenosis; 2) anomalous coronary artery arising from the pulmonary artery; and 3) idiopathic progressive heart failure. During circulatory support with VAD, each child had coagulation times maintained at 1.5-2.5 times normal. Each child had normal or mildly reduced renal function. Each of these children had imaging studies (ultrasound or computed tomography) while receiving VAD support, which demonstrated enlarged echogenic kidneys. These children had coagulation parameters within recommended ranges. These children subsequently died and autopsy studies of two children showed multiple bilateral kidney infracts, parenchymal congestion, and arterial thrombosis. Our case series shows that enlarged and echogenic kidneys may be associated with thromboembolism of the renal artery in pediatric patients on VAD. We were not able to identify a specific cause-and-effect relationship.