Outcomes of delayed Norwood operation in high-risk patients–time to reconsider the dogma of a primary Norwood operation?

OBJECTIVES: The delayed Norwood approach, preceded by bilateral pulmonary artery banding, has emerged as a strategy to improve outcomes in high-risk infants by addressing neonatal hemodynamic instability and organ immaturity. METHODS: This single-center, retrospective study analyzed 20 consecutive patients with hypoplastic left heart syndrome/variants and multiple risk factors who underwent a delayed Norwood operation following bilateral pulmonary artery banding between 2019 and 2024. RESULTS: Bilateral pulmonary artery banding was performed at a median age of 2.5 days (IQR: 2-4). Preoperative risk factors included prematurity (35%), low birth weight <2.5 kg (25%), non-cardiac comorbidities (25%), genetic syndromes (50%), preoperative cardiogenic shock (35%), and restrictive atrial septum (25%). The median age at delayed Norwood was 36 days (IQR: 29-79), with an operative survival rate of 75%. Patients who underwent the delayed Norwood within 4 weeks of bilateral pulmonary artery banding did not require any pulmonary artery reinterventions. Median lactate clearance time was 8 hours (IQR: 5-18), and the median vasoactive inotropic score decreased by 47% within 48 hours postoperatively. Cerebral near-infrared spectroscopy values improved in patients without postoperative ECMO support from 53% to 58% and 63% at 0, 12, and 36 hours, respectively. CONCLUSION: The delayed Norwood approach, preceded by initial bilateral pulmonary artery banding in a high-risk patient cohort, achieved surgical outcomes comparable to those of lower-risk patients undergoing primary Norwood operation. A delayed Norwood procedure around 4-6 weeks of following bilateral pulmonary artery banding may improve survival rates in high-risk patients with reduction of surgical or catheter-based reinterventions.