Computational fluid dynamics in paediatric cardiac surgery.

Computational fluid dynamics techniques have been applied to study both the local and the global haemodynamics created by different surgical reconstructions, currently used to treat complex congenital heart defects. These operations are characterised by competition of flows which can lead to postoperative failure of the surgical treatment. Different techniques have been used in order to improve knowledge of the global haemodynamics in patients submitted to such operations, and to devise possible optimal hydraulic designs of the connections. The adopted approach has combined highly-detailed, three-dimensional models of the connections with simplified zero-dimensional, lumped-parameter network models of the overall circulation of the patient. Three-dimensional models of the connections have been developed by means of the finite element method. Local fluid dynamics features have been analysed and then 'incorporated' in mathematical models able to predict some clinically relevant postoperative haemodynamic data. Results emphasise the impact of local geometry on global haemodynamics.