Hybrid Strategy for Neonates With Ductal-Dependent Systemic Circulation at High Risk for Norwood

Hypoplastic left heart syndrome and other cardiac lesions with ductal-dependent systemic circulation continue to be challenging to manage, especially in high-risk (HR) populations (those with prematurity, multiple congenital anomalies, moderate to severe tricuspid regurgitation, hemodynamic instability, intact atrial septum).

A retrospective study on our institution's experience implementing a hybrid strategy as initial palliation in HR patients with ductal-dependent systemic circulation in HR patients undergoing Norwood versus hybrid procedure. From July 2004 to May 2008, 16 HR patients underwent stage I Norwood procedure. After implementation of a hybrid strategy in 2008, 24 HR patients underwent hybrid procedure from May 2008 to November 2015.

There was no difference in gestational age, age at procedure, or hospital length of stay. The HR Hybrid group had lower mean weight (2.6 kg vs 3.1 kg, p = 0.026). Thirty-day mortality was lower in the HR Hybrid group (4% vs 31%, p = 0.019), although there was no difference in interstage mortality (17% vs 9%, p = 0.396). Catheter-based reintervention was more prevalent in the HR Hybrid group, but did not have a negative impact on survival. One-year transplant-free survival was similar (p = 0.416). HR Hybrid patients weighing less than 2.6 kg had higher overall survival (83% vs 25%, p = 0.013), as did patients who were premature (70% vs 0%, p = 0.003).

In high-risk patients, the hybrid procedure appears to have lower 30-day mortality and may have a survival benefit in premature patients and those less than 2.6 kg. Long-term attrition in this high-risk population is ongoing regardless of early strategy.