Norwood Stage I Palliation in Patients Less Than or Equal to 2.5 kg: Outcomes and Risk Analysis

Background: Hospital mortality of stage I palliation in patients with hypoplastic left heart syndrome and weighing less than or equal to 2.5 kg remains high. We aimed to (1) assess outcomes in this specific population in a dedicated neonatal cardiac program and (2) determine factors associated with poor outcomes.

Methods: We retrospectively analyzed outcomes in patients weighing less than or equal to 2.5 kg who underwent a stage I palliation at our institution (2006 to 2014) and performed a risk analysis. Twenty-eight patients were included. Mean follow-up was 26.2 ± 27 months.

Results: Median weight at surgery was 2.29 kg (range, 1.3 to 2.5 kg). A Sano conduit as opposed to a Blalock-Taussig shunt was placed in 22 patients (78.6%). Timing of surgery was delayed in 5 patients (18%) because of prematurity or extracardiac condition. Coronary fistulae, ventricular dysfunction, and greater than moderate atrioventricular valve regurgitation were present in 2 patients each. Hospital mortality rate was 10.7% (3 of 28 patients). One patient (3.7%) required an early, unplanned reintervention, and 1 patient underwent a late arch revision at the time of stage II. Late mortality or heart transplant rate was 8% (2 of 25 patients). Stage II and stage III procedures were performed in 19 (76%) and 8 (32%) survivors. Survival after stage 2 palliation was 100% (19 of 19 patients) and 87% after Fontan (7 of 8 patients). On univariate analysis, low birthweight (p = 0.03), delayed surgery (p = 0.05), preoperative comorbidities (p = 0.03), postoperative extracorporeal membrane oxygenation (p = 0.04), neurologic complications (p = 0.03), and dialysis (p = 0.04) were associated with higher hospital mortality.

Conclusions: Stage-I palliation in patients with hypoplastic left heart syndrome weighing less than or equal to 2.5 kg can be achieved with good early and late outcomes. Very low birth weight, delayed surgery, comorbidities, and severe postoperative complications were associated with higher hospital mortality.