Pekkan Cardiovascular Biofluids Group, Biomedical Engineering Deparment, Carnegie Mellon University

Improving neonatal cerebral perfusion during cardiopulmonary bypass

Staged palliation of complex congenital heart defects requires open heart surgeries very early in life. Radical surgical reconstructions of the circulation system result in drastic differences in pre- and post-operative systemic-to-pulmonary flow (Qp/Qs) and cardiac loading which can be realized through the increased physiological plasticity of the neonatal patient. Prolonged cardiopulmonary bypass (CPB) is usually required during these surgeries affecting 20,000 children annually. There are well acknowledged deterious affects of standard CPB techniques on neonates, including higher inflammation risk, premature Circle of Willis, unbalanced, non-physiological organ perfusion resulting in temporary or permanent brain damage in up to 25% of patients.

neonatal cpb

Biomechanical design of improved neonatal CPB circuit components, which is challenged by complex pulsatile and cavitating flows, has to be customized for the patient-specific anatomy and physiology. Geometrically scale-down versions of established adult scale designs have historically demonstrated poor outcome especially in blood damage indices. Most importantly, neonatal cardiac output requirement remain relatively high that challenges the successful biomechanical design of small diameter pediatric cannulas resulting in high blood trauma due to pulsatile jet-like flow regimes. An experimentally validated computational fluid dynamics analysis methodology will be instrumental in achieving optimal hemodynamic performance and eventually will bring the poor neonatal CPB outcome close to the adult CPB values. (This research is conducted with close collabortion of Prof. Akif Undar of Penn state)