Comparative outcomes of pulmonary artery changes in ductal-patency-dependent pulmonary circulation: Patent ductus arteriosus stent versus modified Blalock–Taussig shunt

Background Neonates with ductal-dependent pulmonary blood flow (DP-PBF) require timely palliation to maintain pulmonary perfusion. Patent ductus arteriosus (PDA) stenting has emerged as a less invasive alternative to modified Blalock–Taussig shunt (mBTS), but comparative data on longitudinal pulmonary artery growth and clinical outcomes remain limited. Methods This multicenter retrospective cohort study included infants with DP-PBF who underwent PDA stenting or mBTS as first-stage palliation at Queen Sirikit National Institute of Child Health and Songklanagarind Hospital, Thailand, between January 2017 and December 2022. Pulmonary artery growth was assessed using the McGoon ratio and Nakata index at baseline, 2 months, and 12 months. Longitudinal changes were analyzed using linear mixed-effects models with adjustment for ventricular physiology. Procedural complications were compared, and mortality was evaluated using Kaplan–Meier analysis, Cox regression, and 12-month restricted mean survival time. Results Eighty-six infants were included: 41 underwent PDA stenting and 45 underwent mBTS. Baseline pulmonary artery measurements were comparable, although diagnostic composition differed between groups. At 2 months, PDA stenting was associated with greater pulmonary artery growth than mBTS, with a higher McGoon ratio (mean difference, 0.18; 95% CI, 0.05–0.31; p = 0.005) and Nakata index (mean difference, 51.2 mm 2 /m 2 ; 95% CI, 23.0–79.5; p < 0.001). By 12 months, the Nakata index was similar between groups (p = 0.90), whereas a statistically significant between-group difference in McGoon ratio remained (mean difference, 0.15; 95% CI, 0.02–0.29; p = 0.028). Procedural complications were less frequent after PDA stenting than after mBTS (17.1% vs 57.8%; risk ratio for mBTS vs PDA stenting, 3.38; 95% CI, 1.65–6.95; p = 0.001). Although mortality was numerically lower after PDA stenting, time-to-event analyses did not show a statistically significant survival difference. Conclusions In this cohort, PDA stenting was associated with greater early pulmonary artery growth and fewer observed procedural complications compared with mBTS. By 12 months, the Nakata index was similar between groups, whereas a statistically significant difference in McGoon ratio remained. These findings should be interpreted cautiously because of non-randomized treatment allocation, differences in diagnostic composition, and potential residual confounding.