Survival After Norwood Procedure in High-Risk Patients

Background: Multiple single-ventricle populations are noted to be at increased risk for mortality after the Norwood procedure. Preoperative risk factors include low birth weight, restrictive/intact atrial septum, obstructed pulmonary veins, ventricular dysfunction, and atrioventricular valve regurgitation. We report outcomes of the Norwood procedure in standard- and high-risk patients in the recent era.

Methods: All patients born with hypoplastic left heart syndrome between 2006 and 2016 who underwent a Norwood procedure at our institution were included. Patient data were retrospectively reviewed, and Kaplan-Meier analysis was used to evaluate survival between groups.

Results: The cohort included 177 patients. Fifty patients were determined high-risk preoperatively: low birth weight (n = 18), ventricular dysfunction/atrioventricular valve regurgitation (n = 13), intact or restrictive atrial septum/obstructed anomalous pulmonary venous return (n = 14), and multiple factors (n = 5). There were 2 (1.6%) deaths before Glenn in the standard-risk group, with a total of 10 (20%) from the high-risk groups (P < .0001). Survival at 1 year differed greatly between groups, with highest being standard risk at 89% and lowest in the intact septum/obstructed veins group at 54%. The difference between groups in long-term survival was significant (P < .001).

Conclusions: Outcomes after the Norwood procedure have improved for standard-risk patients. Those with preoperative risk factors account for most of the early deaths after the Norwood procedure. This high-risk status does not resolve after Glenn, because longer-term survival continues to diverge from the standard-risk group.