Comparison of different cannulation approaches for Cardio Pulmonary Bypass
The cerebral perfusion can be insufficient during Cardio Pulmonary Bypass (CPB) operations. The outflow cannula position influences the flow field in the cardiovascular system, whereby end organ perfusion is affected. There are different cannulation approaches for CPB. A Computational Fluid Dynamics study was initially undertaken to compare cannulation of the ascending aorta, regarding different cannula positions, and cannulation of the right subclavian artery, with regard to the distance between the cannula tip and the vertebral artery. Usual CPB conditions were assumed for both approaches. The models were created from CT/MRI records of young to middle-aged healthy patients. The cannula jet appears to be the main reason for the loss in cerebral perfusion seen clinically during CPB. Also, the results suggest that cannulation of the subclavian artery provides the best flow distribution if the cannula tip is a few mm away from the vertebral artery branch. For cannulation of the ascending aorta, the cannula should be placed sagital from the left body side. The presented method can be adapted for other clinical applications, e.g. support conditions of Ventricular Assist Devices. Flow fields, pressure, stress and shear rates can be analysed, which may be used for evaluation and development of new products and applications.
KeywordsComputational Fluid Dynamics Cardio Pulmonary Bypass Outflow Cannula Flow distribution
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