Is a hybrid strategy a lower-risk alternative to stage 1 Norwood operation?

• Published in: The Journal of thoracic and cardiovascular surgery Vol. 153; no. 1; pp. 163 - 172.e6
• Main Authors: Wilder, Travis J., MD, McCrindle, Brian W., MD, Hickey, Edward J., MD, Ziemer, Gerhard, MD, PhD, Tchervenkov, Christo I., MD, Jacobs, Marshall L., MD, Gruber, Peter J., MD, PhD, Blackstone, Eugene H., MD, Williams, William G., MD, DeCampli, William M., MD, PhD, Caldarone, Christopher A., MD, Pizarro, Christian, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-01-2017
• Subjects: Age Factors; Birth Weight; Blalock-Taussig Procedure - adverse effects; Blalock-Taussig Procedure - mortality; Canada; Cardiothoracic Surgery; congenital heart disease; critical left ventricular outflow tract obstruction; Female; Fontan Procedure; Heart Defects, Congenital - diagnostic imaging; Heart Defects, Congenital - mortality; Heart Defects, Congenital - physiopathology; Heart Defects, Congenital - surgery; Heart Transplantation; Humans; hybrid; hypoplastic left heart syndrome; Infant, Newborn; Male; Norwood; Norwood Procedures - adverse effects; Norwood Procedures - mortality; Palliative Care; Prospective Studies; Recovery of Function; Risk Factors; single ventricle; Time Factors; Treatment Outcome; United States; Ventricular Outflow Obstruction - diagnostic imaging; Ventricular Outflow Obstruction - mortality; Ventricular Outflow Obstruction - physiopathology; Ventricular Outflow Obstruction - surgery; Canada; United States; Congenital Heart Surgeons' Society; KM; hypoplastic left heart syndrome; single ventricle; NW-BT; NW-RVPA; deep hypothermic circulatory arrest; critical left ventricular outflow tract obstruction; Norwood with modified Blalock-Taussig shunt; left ventricular outflow tract obstruction; Norwood; BSA; hybrid; CPB; Norwood with right ventricle–pulmonary artery conduit; LVOTO; congenital heart disease; cardiopulmonary bypass; Kaplan-Meier; CHSS; DHCA; body surface area
• ISSN: 0022-5223; 1097-685X
• DOI: 10.1016/j.jtcvs.2016.08.021

Abstract Background For neonates with critical left ventricular outflow tract obstruction (LVOTO), hybrid procedures are an alternative to the Norwood stage 1 procedure. Despite perceived advantages, however, outcomes are not well defined. Therefore, we compared outcomes after stage 1 hybrid and Norwood procedures. Methods In a critical LVOTO inception cohort (2005-2014; 20 institutions), a total of 564 neonates underwent stage 1 palliation with the Norwood operation with a modified Blalock-Taussig shunt (NW-BT; n = 232; 41%), Norwood operation with a right ventricle–to–pulmonary artery conduit (NW-RVPA; n = 222; 39%), or a hybrid procedure (n = 110; 20%). Post–stage 1 outcomes were analyzed via competing-risks and parametric hazard analyses and compared among all 564 patients and between patients who underwent propensity-matched hybrid and those who underwent NW-BT/NW-RVPA. Results By 6 years after the stage 1 operation, 50% ± 3%, 7% ± 2%, and 4% ± 1% of patients transitioned to Fontan, transplantation, and biventricular repair, respectively, whereas 7% ± 2% were alive without transition and 32% ± 2% died. Risk factors for death without transition included procedure type, smaller ascending aorta, aortic valve atresia, and lower birth weight. Risk-adjusted 4-year survival was better after NW-RVPA than after NW-BT or hybrid (76% vs 60% vs 61%; P  < .001). Furthermore, for neonates with lower birth weight (<∼2 kg), an interaction between birth weight and hybrid resulted in a trend toward better survival after hybrid compared with NW-BT or NW-RVPA. For propensity-matched neonates between hybrid and NW-BT (88 pairs), 4-year survival was similar (62% vs 57%; P  = .58). For propensity-matched neonates between hybrid and NW-RVPA (81 pairs), 4-year survival was better after NW-RVPA (59% vs 75%; P  = .008). Conclusions For neonates with critical LVOTO undergoing single-ventricle palliation, NW-RVPA was associated with the best overall survival. Hybrid strategies are not a lower-risk alternative to Norwood operations overall; however, the impact of lower birth weight on survival may be mitigated after hybrid procedures compared with Norwood operations.