BackgroundStage 1 palliation of hypoplastic left heart syndrome entails use of the Norwood operation with a modified Blalock-Taussig shunt or a right ventricle-to-pulmonary artery shunt, or the hybrid procedure. Use trends and factors influencing palliation selection remain unclear. We aimed to evaluate these questions and to compare outcomes between types of stage 1 palliation. MethodsThe National Pediatric Cardiology Quality Improvement Collaborative phase 1 (June 2008-August 2016) and phase 2 (August 2016-September 2019) databases were used. Procedure type was assessed by operation year. Baseline characteristics and annual hospital volume were evaluated. Postsurgical admission duration and outcomes were compared. ResultsA total of 3497 patients were included, 30.8% with modified Blalock-Taussig shunt, 59.7% with right ventricle-to-pulmonary artery shunt, and 9.5% with hybrid. Use of the right ventricle-to-pulmonary artery shunt increased over time (P = .02). This increase was similar among all hospital volumes. Higher hospital volume (odds ratio [OR], 1.2; 95% CI, 1.1-1.4; P = .003), male sex (OR, 1.3; 95% CI, 1.1-1.6; P = .01), and isolated cardiac disease (OR, 1.33; 95% CI, 1.01-1.55; P = .05) were associated with relatively higher likelihoods of a modified Blalock-Taussig shunt. Mortality/transplant rates before stage 2 palliation were higher with the modified Blalock-Taussig shunt than with the right ventricle-to-pulmonary artery shunt (12.3% vs 9.6%, P = .03). ConclusionsIn stage 1 palliation, use of right ventricle-to-pulmonary artery shunts has increased over time, use of modified Blalock-Taussig shunts has decreased, and use of hybrids was unchanged. The modified Blalock-Taussig shunt has a higher likelihood of use in higher-volume centers, males, and less complex patients but is associated with longer hospitalizations and lower transplant-free survival to stage 2 palliation.