*4.1.4 Hypoplastic left heart syndrome*

Neonates with hypoplastic left heart syndrome usually have Norwood palliation (**Figure 2**) [37, 59] in the neonatal period; in this operation, the following procedures are performed: (1) the main pulmonary artery and the aorta are anastomosed together; additional prosthetic material is used as needed; (2) the pulmonary circulation receives blood supply by connecting the aorta to the PA via a modified BT shunt [51] (**Figure 2b**); (3) atrial septum is excised to allow unhindered blood flow from the left to the atrium; and (4) ductal tissue is removed, and coarctation of the aorta, if present is repaired. Some surgeons use alternative Sano shunt [60], connecting the RV outflow tract to the PA (**Figure 2c**) instead of BT shunt.
