Norwood Procedure — Procedure Guide, Recovery & Risks | MyMedicPlus

The Norwood procedure is Stage I surgical palliation for hypoplastic left heart syndrome (HLHS), a severe congenital defect where the left ventricle is underdeveloped. It establishes unobstructed systemic blood flow from the right ventricle via a reconstructed neo-aorta.

Performed on neonates within the first week of life with HLHS or functionally equivalent single-ventricle defects where the left ventricle cannot support systemic circulation. Prostaglandin E1 maintains ductal patency until surgery.

On cardiopulmonary bypass with deep hypothermic circulatory arrest, surgeons reconstruct the aorta using the pulmonary trunk (neo-aorta), place either a Blalock-Taussig (BT) shunt or Sano right ventricle-to-pulmonary artery conduit, and perform atrial septectomy.

Neonates require 2–4 weeks in the paediatric cardiac ICU with intensive haemodynamic monitoring. Inter-stage home monitoring with pulse oximetry is mandatory between Stage I and Stage II Glenn procedure at 4–6 months.

The Norwood carries 25–30% 30-day mortality at experienced centres, the highest of any congenital cardiac procedure. Risks include low cardiac output syndrome, shunt thrombosis, neurological injury, and inter-stage sudden death (5–15%).

Survival to Fontan completion (Stage III) is 50–70% at high-volume centres. BT shunt and Sano conduit have comparable long-term survival. Neurodevelopmental outcomes require long-term support with specialist follow-up into adulthood.