Neonates with ductal patency–dependent pulmonary blood flow (DP-PBF) require timely palliation to maintain pulmonary perfusion until definitive repair or staged reconstruction. Traditional surgical palliation with the modified Blalock–Taussig shunt (mBTS) secures pulmonary blood flow but carries operative and postoperative morbidity. Patent ductus arteriosus (PDA) stenting is a less invasive catheter-based alternative that avoids thoracotomy and may shorten hospitalization, though stent-related adverse events remain a concern.
A key objective of first-stage palliation is to promote branch pulmonary artery (PA) growth, since PA dimensions affect the feasibility and complexity of subsequent interventions. Quantitative indices commonly used in follow-up include the McGoon ratio and the Nakata index, which provide complementary assessments of PA adequacy relative to systemic arterial size and body surface area, respectively. The primary aim of this multicenter retrospective cohort study was to compare PA growth after PDA stenting versus mBTS. Secondary aims included comparing procedural complications and mortality.
This study retrospectively reviewed neonates with DP-PBF treated between January 2017 and December 2022 at Queen Sirikit National Institute of Child Health and Songklanagarind Hospital, Thailand. Institutional ethics approvals were obtained, and datasets were anonymized prior to analysis.
Infants aged under 60 days with DP-PBF who underwent first-stage palliation with either PDA stenting or mBTS were eligible. Patients who crossed over to an alternative treatment after the index procedure or lacked PA measurements at the predefined follow-up time points were excluded from longitudinal growth analyses. All patients receiving the index procedure were included in analyses of procedural complications and mortality.
Baseline demographics and clinical variables were extracted from medical records, including weight, oxygen saturation, cardiac diagnosis, and baseline PA dimensions. PA growth was assessed using the McGoon ratio and Nakata index at baseline, 2 months, and 12 months. Branch PA symmetry was evaluated using the left-to-right PA diameter ratio (LPA/RPA) at the same time points. Procedural complications were recorded for all index procedures. Mortality was analyzed using time-to-event methods.
Treatment selection—PDA stenting versus mBTS—was determined by the multidisciplinary treating team based on institutional practice, patient anatomy, ventricular physiology, ductal morphology, and procedural feasibility. Generally, PDA stenting was chosen for ducts amenable to transcatheter intervention; mBTS was favored for patients with univentricular physiology, markedly tortuous ducts, or anatomy considered unsuitable for stenting. PDA stenting was performed under general anesthesia using standard transcatheter techniques; prostaglandin E1 infusion was stopped 6–8 hours before the procedure.
Longitudinal changes in PA indices were analyzed using linear mixed-effects models adjusted for ventricular physiology. Procedural complications were compared between groups with risk ratios. Mortality was evaluated using Kaplan–Meier analysis, Cox regression, and 12-month restricted mean survival time. The authors accounted for available confounders but acknowledged non-randomized allocation and potential residual confounding.
Eighty-six infants met inclusion for the cohort: 41 underwent PDA stenting and 45 underwent mBTS. Baseline PA measurements were reported as comparable between groups, though the diagnostic composition of each group differed.
At 2 months, infants treated with PDA stenting demonstrated greater PA growth than those who underwent mBTS. Specifically, the McGoon ratio was higher after PDA stenting (mean difference 0.18; 95% CI, 0.05–0.31; p = 0.005). The Nakata index was also higher at 2 months in the PDA stent group (mean difference 51.2 mm2/m2; 95% CI, 23.0–79.5; p < 0.001).
By 12 months, the Nakata index did not differ significantly between groups (p = 0.90), indicating convergence in cross-sectional PA area normalized to body surface area. However, a statistically significant between-group difference in McGoon ratio persisted at 12 months (mean difference 0.15; 95% CI, 0.02–0.29; p = 0.028).
Branch PA symmetry was evaluated using the LPA/RPA ratio at baseline, 2 months, and 12 months. The source article reports these assessments but does not indicate major between-group asymmetry as a primary finding in the abstract; detailed values and time-course are presented in the full article tables and figures.
Procedural complications were substantially less frequent after PDA stenting (17.1%) compared with mBTS (57.8%). The calculated risk ratio for complications with mBTS versus PDA stenting was 3.38 (95% CI, 1.65–6.95; p = 0.001). The authors note that mBTS is associated with operative and postoperative thoracic and nerve-related complications reported in prior literature; PDA stents carry device-specific risks such as ductal dissection, stent thrombosis, or migration.
Mortality was numerically lower in the PDA stenting group, but time-to-event analyses—including Kaplan–Meier curves, Cox regression, and 12-month restricted mean survival time—did not identify a statistically significant difference in survival between groups.
In this cohort, PDA stenting was associated with greater early PA growth (2 months) and fewer observed procedural complications compared with mBTS. By 12 months the Nakata index was similar between groups, while a modest but statistically significant difference in McGoon ratio remained. The authors emphasize cautious interpretation because treatment allocation was non-randomized, diagnostic mix differed between groups, and residual confounding may persist.
Key limitations include the retrospective design, non-randomized selection of palliation strategy, differences in diagnostic composition between groups, and potential unmeasured confounding. The dataset is not publicly available; de-identified data may be shared on request subject to institutional approvals as described in the source article.
Among neonates with DP-PBF in this multicenter retrospective cohort, PDA stenting showed greater early PA growth and fewer procedural complications compared with mBTS. By one year the Nakata index converged between groups though the McGoon ratio difference persisted. These findings warrant cautious interpretation and further study, ideally in prospective or randomized settings.