P2.C053: Norwood procedure timing and patient outcomes in hypoplastic left heart syndrome

Background: Hypoplastic left heart syndrome (HLHS) is a congenital heart defect that affects the development of the left side of the heart. If left untreated, this condition is fatal, often within a few hours or days of birth. The first step in treating HLHS is the Norwood Procedure (NP), which provides unobstructed blood flow through a reconstructed aortic shunt and creates unrestricted communication between the atria. However, the optimal timing of this procedure is still a topic of debate, with some experts suggesting that earlier procedures lead to better outcomes.

Methods: The purpose of this study was to assess whether timing was a factor associated with overall mortality and length of stay (LOS) in patients with HLHS or a related single ventricle anomaly who underwent NP at the only pediatric cardiac surgery center in Puerto Rico and the Caribbean between June 2017 and June 2021. This is a retrospective medical chart review of patients who met the inclusion criteria. Differences in LOS among groups were evaluated using an unpaired t-test with Welch's correction after conducting the normality test. A Chi-square analysis was performed to determine differences in mortality among the groups.

Results: During the study period, 18 patients met the inclusion criteria. It was found that there was no difference in the survival rate between patients who underwent an early NP (60%) and those who underwent a late NP (77%) (p=0.48). However, patients who received an early NP had a shorter length of stay (LOS) of 8.2 days in the Cardiac ICU, compared to 13.3 days for those who received a late NP. This means there was a significant difference in the time it took for patients to be discharged from the Cardiac ICU between those who underwent the procedure earlier and those who underwent it later (p=0.006). Despite the difference in LOS in the Cardiac ICU, there was no significant difference in the overall hospital LOS between patients who received an early NP (29.4 days) and those who received a late NP (42.7 days) (p=0.3).

Conclusion: According to this study, the survival rate of patients who underwent the Norwood procedure did not significantly differ based on whether the procedure was performed before or after 14 days of age or the length of hospital stay. The study suggests that the key to improving survival rates for these patients lies in the pre-operative management and identification of other co-existing medical conditions.