Computational Modeling of Neonatal Cardiopulmonary Bypass Hemodynamics With Full Circle of Willis Anatomy.
Cardiopulmonary bypass (CPB) procedure is employed to repair most congenital heart defects (CHD). Cannulation is a critical component of this procedure where the location and diameter of cannula controls the hemodynamic performance. State-of-the-art computational studies of neonatal CPB employed an isolated aortic arch region by truncating the three-dimensional (3D) patient-specific cerebral system. The present work expanded these studies where the 3D patient-specific MRI reconstruction of the cerebral system, including the Circle of Willis (CoW), is integrated with a hypoplastic neonatal aortic arch. The inlet of the arterial cannula is assigned a steady velocity boundary condition of the CPB pump, while all outlets are modeled as resistance boundary conditions, thus allowing acute comparisons between different cannula configurations. Three-dimensional (3D) flow simulations in the aortic arch model are performed at a Reynolds number of 2150 using an experimentally validated commercial solver. Results demonstrate that the inclusion of 3D CoW is essential to predict the accurate head-neck blood perfusion and therefore critical in deciding the neonatal aortic cannulation strategy preoperatively. Using this integrated model two CPB configurations are studied, where the cannulas were placed at innominate artery (IA) (IA-cannula configuration) and ductus arteriosus (DA) (DA-cannula configuration). Configuration change produced significant differences in flow splits and local hemodynamics of blood flow throughout the whole aortic arch, neck and cerebral arteries. Percent flow rate differences between the IA- and DA-cannula configurations are computed to be: 19%, for descending aorta, 198% for ascending aorta (perfusing coronary arteries), 91% for right anterior cerebral artery, and 68% for left anterior cerebral artery. Another important finding is the retrograde flow at vertebral arteries for IA-cannula configuration, but not for DA-cannula. These results may help to translate better neonatal arterial cannulae design for minimizing cerebral complications during CPB procedures.
Department of Mechanical Engineering, Koc University, Istanbul, Turkey.
Senol
S
Piskin
Pediatric Cardiovascular Research Center, Department of Pediatrics, Surgery and Bioengineering, Penn State Hershey College of Medicine, Hershey, PA, USA.
Akif
A
Ündar
Department of Mechanical Engineering, Koc University, Istanbul, Turkey.|Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
Kerem
K
Pekkan
D001013:Aorta, Thoracic / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D006328:Cardiac Catheterization / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000379:methods; D002536:Cerebral Arteries / Q000033:anatomy & histology / Q000502:physiology; D002941:Circle of Willis / Q000033:anatomy & histology* / Q000502:physiology; D003198:Computer Simulation; D006330:Heart Defects, Congenital / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007231:Infant, Newborn
Blood flow; Cardiopulmonary bypass; Circle of Willis; Computational fluid dynamics validation; Congenital heart disease; Neonatal aortic arch; Wall shear stress