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Pierce-Donachy pediatric VAD: progress in development
B B Daily1, T W Pettitt, S P Sutera
1Division of Cardiothoracic Surgery, Washington University, St. Louis, Missouri, USA.
Insights
Developing pediatric ventricular assist devices is crucial for neonates. New bileaflet valves show promise in improving flow dynamics and reducing thrombus formation in these critical devices.
Area of Science:
- Biomedical Engineering
- Pediatric Cardiology
- Medical Device Development
Background:
- Pediatric ventricular assist devices (VADs) are lacking, despite adult VAD success.
- Neonates (3-5 kg) requiring VADs for cardiogenic shock or transplant bridge face challenges with scaled-down adult devices.
- Small valves and thrombus formation hinder pediatric VAD development.
Purpose of the Study:
- Report progress on the Pierce-Donachy pediatric ventricular assist device.
- Incorporate 10-mm bileaflet valve prototypes for pediatric VADs.
- Quantify internal pump velocity fields using particle image velocimetry.
Main Methods:
- Development of the Pierce-Donachy pediatric ventricular assist device.
- Utilizing 10-mm-diameter bileaflet valve prototypes.
- Employing particle image velocimetry (PIV) for flow analysis.
Main Results:
- PIV velocity maps reveal complex flow patterns within the pediatric VAD.
- Flow complexity suggests potential for hemodynamic improvement with optimized valves.
- Ongoing animal tests will assess thrombus reduction via improved flow and surface "washing".
Conclusions:
- Optimizing valve hemodynamics may improve flow patterns in pediatric VADs.
- Further research is needed to confirm reduced thrombus formation.
- Successful pediatric VAD development requires addressing flow dynamics and hemocompatibility.
Background:
Despite the successful use of ventricular assist devices in adults over the past 15 years, relatively little has been done to develop similar devices for pediatric patients. Consequently, no such device is currently available. A review of clinical data suggests that the majority of patients in need of a pediatric ventricular assist device, either for postcardiotomy cardiogenic shock or as a bridge to cardiac transplantation, are neonates weighing 3 to 5 kg. Attempts to "scale down" an adult blood pump to make an appropriate device for these patients have been difficult due to the lack of sufficiently small, commercially available valves and the tendency for thrombus to develop in these small pumps.
Methods:
We report on progress in the development of the Pierce-Donachy pediatric ventricular assist device, which incorporates 10-mm-diameter bileaflet valve prototypes. Particle image velocimetry is used to quantify the velocity field inside the pump.
Results And Conclusions:
Particle image velocimetry velocity maps demonstrate the complexity of the flow patterns in these pumps and suggest that improved flow patterns may result from the use of valves with improved hemodynamic performance. Animal tests to determine whether improved flow patterns and better "washing" of the pump's blood-contacting surfaces will reduce thrombus formation are underway.