PROGRESS WITH THE PEDIATRIC CARDIOPULMONARY ASSIST SYSTEM

Abstract

The success of extracorporeal membrane oxygenation (ECMO) in neonates has been demonstrated. However, this technique has not significantly evolved since its introduction by Bartlett in 1975. Current complications include difficulty managing venous return, system complexity, and morbidities associated with biocompatibility of the circuit. A recent report from the Extracorporeal Life Support Registry underscores morbidities associated with biocompatibility citing bleeding, hemolysis, and seizure as major patient-related complications. Ension and its development partner, the University of Louisville, have begun a program to address these key clinical complications with a miniature, integrated pump-oxygenator. The initial focus of this effort is a system for patients up to 12 kg that would facilitate improved parent-child bonding. A key feature of this system is a heparin-based hollow fiber coating explicitly designed to minimize resistance to mass exchange - a critical requirement for the ECMO application. Four candidate coatings have been developed and tested in vitro to assess both bioactivity and impact on oxygen and carbon dioxide transfer. Other development efforts include leverage of computational fluid dynamics (CFD) techniques to optimize blood flow and mass exchange characteristics, development of a custom purged blood seal for long-term use, and design of a control scheme allowing semi-automated operation. Initial prototypes of the proposed system have been tested in vitro and in vivo at the University of Louisville yielding favorable results.