Medical Student McGill University Montréal, Quebec, Canada
Background: Tetralogy of Fallot (TOF), particularly when associated with pulmonary atresia, is a common cyanotic congenital heart defect marked by restricted pulmonary arterial blood flow. In neonates, early palliation is often required to promote pulmonary artery growth before complete repair. Two primary approaches include transcatheter right ventricular outflow tract (RVOT) stenting and surgical palliation with a transannular patch (TAP), the latter being less common in North America. This study compares pulmonary artery growth and clinical outcomes between these two strategies.
METHODS AND RESULTS: We retrospectively analyzed cyanotic TOF neonates (with or without pulmonary atresia) who underwent RVOT stenting or a restrictive TAP between 2015–2025 at a single center. Primary outcome was suboptimal pulmonary artery development, defined by a post-palliation Nakata index ≤150 mm²/m². Secondary outcomes included changes in left and right pulmonary artery (LPA/RPA) Z-scores, length of stay (LOS), and mortality. Data sources included echocardiography, catheterization, scintigraphy, and clinical records. Z-scores were calculated using the Boston Children’s Hospital tool. Among 38 patients (60.5% female, 28.9% with genetic syndromes), median age at palliation was 18 days [IQR 8–40]. Of these, 25 (65.8%) underwent TAP, and 13 (34.2%) had RVOT stenting. Pulmonary atresia was more frequent in the surgical group (72.0% vs. 23.1%). Baseline Nakata index and LPA/RPA Z-scores were comparable between groups. Post-palliation, both strategies significantly improved Nakata index (TAP: from 90.0±68.9 to 238.9±116.7 mm²/m²; stenting: from 93.5±45.2 to 215.5±59.0 mm²/m²; both p< 0.001) (Figure 1). A Nakata index ≤150 mm²/m² was seen in 22.7% of TAP and 15.4% of stented patients (p=0.69) (Table 1). ICU LOS was significantly shorter in the stented group (1.9±3.5 vs. 9.0±6.8 days; p< 0.001). RPA Z-scores improved significantly in the TAP group (from -2.16±1.29 to -0.32±2.27; p=0.001), but not in the stented group. LPA Z-scores did not change significantly in either group. One in-hospital death occurred in the surgical cohort (4.0%). Definitive repair was ultimately achieved in 84.0% of TAP and 84.6% of stented patients (p>0.9) after a median delay of 10 months [IQR 7–25] for TAP and 8 months [IQR 6–16] for stented patients.
Conclusion: Both transcatheter and surgical palliation effectively promote pulmonary artery growth and enable timely complete repair in TOF newborns. Despite limited use in North America, surgical restrictive TAP palliation remains a viable and effective strategy. It can be applied with excellent results to infants with complex anatomical variants when stenting is not possible.
