Older age at the time of the Norwood procedure is a risk factor for early postoperative mortality†

The Norwood procedure is commonly used as first-step palliation in children with hypoplastic left heart syndrome or related congenital malformations. In most cases, the operation is carried out during the first week of life. Excessive pulmonary blood flow in univentricular physiology can soon lead to compromised cardiac function and pulmonary hypertension and could have an influence on postoperative outcomes.

Between 1997 and 2011, 257 Norwood procedures were performed at the Kinderherz-Zentrum Linz. Twenty-seven patients were older than 20 days at the time of the Norwood operation without previous pulmonary artery banding. A retrospective analysis of the two age groups was carried out concerning early mortality, interstage mortality and major events until the bidirectional Glenn operation.

Patients older than 20 days had a significantly higher mortality rate before the bidirectional Glenn operation than younger patients (44.4 vs 20.3%; P = 0.002). They also showed a significantly higher need for postoperative inhalative nitric oxide therapy (40.7 vs 14.5%, P = 0.002). Summarized risk for either successful postoperative cardiopulmonary resuscitation (CPR), extracorporeal membrane oxygenation therapy or mortality before the bidirectional Glenn operation was 59.3% in the older age group vs 23.8% in the younger age group (P < 0.001).

Age older than 20 days seems to be an independent risk factor for early postoperative mortality and fatal events after the Norwood procedure. Long-persisting excessive pulmonary blood flow and preoperative cardiac decompensation can be the reason for postoperative lethal pulmonary hypertensive crisis and compromised ventricular function.