What is the purpose of creating an ASD during the Norwood procedure?

Creating an atrial septal defect (ASD) during the Norwood procedure primarily serves to increase systemic blood flow. In patients with hypoplastic left heart syndrome, the left ventricle is underdeveloped, making it incapable of generating adequate systemic circulation. The Norwood procedure aims to redirect blood flow through various surgical modifications, and the ASD plays a crucial role in that process.

By allowing a controlled shunt of blood from the right atrium to the left atrium, the ASD facilitates the mixing of oxygenated and deoxygenated blood, which ultimately helps improve systemic perfusion. This is particularly vital in the context of the Norwood procedure, which is performed on neonates or infants with specific congenital heart defects. The increased systemic blood flow is critical for maintaining adequate oxygen delivery to vital organs until secondary surgical interventions can be performed.

Understanding this function of the ASD within the Norwood procedure is essential for comprehending the overall strategy to stabilize circulation in patients with complex congenital heart conditions.