Designing a Patient-Specific Paediatric Mock Circulatory System to Study the Norwood Circulation

The Stage I of Fontan palliation for neonates with hypoplastic left heart syndrome, namely the Norwood procedure, aims to improve the flow of oxygenated blood in the systemic circulation while at the same time providing blood flow to the pulmonary circulation¹. This surgical operation usually involves enlargement of the hypoplastic aorta by means of a patch, reconstruction of aortic coarctation and increase pulmonary flow. The latter point, at present, is achieved in three different ways: i) a Blalock-Taussig (BT) shunt from the innominate artery to the pulmonary artery, ii) an atrio-pulmonary shunt, referred to as Sano modification² and iii) stenting the ductus arteriosus and banding the pulmonary arteries, referred to as “hybrid” Norwood³. In general, it is clear that the circulation following the Norwood procedure presents a very specific and complex arrangement.