Photo Credit: Iryna Inshyna

The following is a summary of “Volume-Outcome Relationship of Norwood Procedures: Insights from the National Pediatric Cardiology – Quality Improvement Collaborative Database,” published in the January 2025 issue of Surgery by Schäfer et al.

This study examined the relationship between center-specific case volume and patient outcomes following the Norwood procedure for hypoplastic left heart syndrome, utilizing data from the National Pediatric Cardiology Quality Improvement Collaborative registry. Previous research on the impact of center volume on outcomes in hypoplastic left heart syndrome has yielded conflicting results, particularly concerning the role of preoperative high-risk features. This investigation aimed to clarify these associations by categorizing centers based on their Norwood procedure volume into three groups: low-volume (≤5 cases/year), medium-volume (6–10 cases/year), and high-volume (>10 cases/year). Data from 3,397 patients across 69 institutions between 2016 and 2023 were analyzed, comparing preoperative high-risk characteristics, 30-day and 1-year mortality rates, and perioperative morbidity outcomes across these volume categories. The results revealed no significant differences in the frequency of preoperative high-risk features among the three center volume categories for most of the variables considered. 

Importantly, no association between center volume and 30-day mortality was observed. However, low- and medium-volume centers were associated with a significantly higher risk of 1-year mortality. After adjusting for the presence of high-risk features, the odds of 1-year mortality remained significantly higher in low- and medium-volume centers, with odds ratios of 1.40 (95% CI 1.03-1.60, p=0.020) and 1.28 (95% CI 1.05-1.86, p=0.025), respectively. Additionally, patients treated at low- and medium-volume centers experienced more frequent postoperative comorbidities, including a higher need for diagnostic and interventional catheterizations. These findings suggest that lower center volume is associated with poorer long-term outcomes, particularly in terms of 1-year survival and perioperative morbidity. 

High-volume centers were associated with improved survival and lower morbidity, even when adjusting for high-risk preoperative features, highlighting the importance of center volume in the management of hypoplastic left heart syndrome. These results support the idea that specialized, higher-volume centers may provide superior outcomes for patients undergoing the Norwood procedure and underscore the need for careful consideration of center capabilities when planning care for patients with hypoplastic left heart syndrome.

Source: sciencedirect.com/science/article/pii/S0003497525000712