PDA stenting was associated with greater early pulmonary artery growth and fewer procedural complications compared with mBTS, though by 12 months the Nakata index was similar between groups and no statistically significant survival difference was demonstrated.
Key Findings
Results
At 2 months, PDA stenting was associated with significantly greater pulmonary artery growth than mBTS as measured by McGoon ratio.
Mean difference in McGoon ratio at 2 months: 0.18 (95% CI, 0.05–0.31; p = 0.005) in favor of PDA stenting.
Longitudinal changes were analyzed using linear mixed-effects models with adjustment for ventricular physiology.
86 infants were included: 41 underwent PDA stenting and 45 underwent mBTS.
Baseline pulmonary artery measurements were comparable between groups, although diagnostic composition differed.
Results
At 2 months, PDA stenting was associated with significantly greater pulmonary artery growth than mBTS as measured by Nakata index.
Mean difference in Nakata index at 2 months: 51.2 mm²/m² (95% CI, 23.0–79.5; p < 0.001) in favor of PDA stenting.
This represents a clinically meaningful early difference in pulmonary artery cross-sectional area growth.
Multicenter retrospective cohort study conducted at two hospitals in Thailand between January 2017 and December 2022.
Results
By 12 months, the Nakata index was similar between the PDA stenting and mBTS groups.
No statistically significant between-group difference in Nakata index at 12 months (p = 0.90).
This suggests convergence in pulmonary artery cross-sectional growth by the end of the first year.
Pulmonary artery growth was assessed at baseline, 2 months, and 12 months using McGoon ratio and Nakata index.
Results
A statistically significant difference in McGoon ratio between PDA stenting and mBTS persisted at 12 months.
Mean difference in McGoon ratio at 12 months: 0.15 (95% CI, 0.02–0.29; p = 0.028) in favor of PDA stenting.
This indicates that while Nakata index converged, the McGoon ratio remained significantly different at one year.
McGoon ratio and Nakata index measure different aspects of pulmonary artery size and may capture different growth dynamics.
Results
Procedural complications were significantly less frequent after PDA stenting than after mBTS.
Complication rates: 17.1% for PDA stenting versus 57.8% for mBTS.
Risk ratio for mBTS vs PDA stenting: 3.38 (95% CI, 1.65–6.95; p = 0.001).
This represents a more than threefold higher risk of procedural complications with mBTS compared to PDA stenting.
Results
Mortality was numerically lower after PDA stenting, but time-to-event analyses did not demonstrate a statistically significant survival difference between groups.
Mortality was evaluated using Kaplan-Meier analysis, Cox regression, and 12-month restricted mean survival time.
Although PDA stenting showed numerically lower mortality, no statistically significant survival benefit was established.
The lack of statistical significance may reflect limited sample size or residual confounding from non-randomized allocation.
Methods
The study population consisted of 86 infants with ductal-dependent pulmonary blood flow from two centers in Thailand over a six-year period.
Study conducted at Queen Sirikit National Institute of Child Health and Songklanagarind Hospital, Thailand.
Enrollment period: January 2017 to December 2022.
41 infants underwent PDA stenting and 45 underwent mBTS as first-stage palliation.
Diagnostic composition differed between groups, representing a potential source of confounding.
Discussion
The authors caution that findings should be interpreted carefully due to non-randomized treatment allocation, differences in diagnostic composition, and potential residual confounding.
This was a multicenter retrospective cohort study, not a randomized controlled trial.
Differences in underlying diagnoses between the PDA stenting and mBTS groups may have influenced outcomes.
Potential residual confounding was acknowledged as a key limitation despite adjustment for ventricular physiology in mixed-effects models.
What This Means
This research examined two surgical procedures used in newborns who rely on a temporary blood vessel called the ductus arteriosus to get blood to their lungs — a condition called ductal-dependent pulmonary blood flow. The two procedures compared were PDA (patent ductus arteriosus) stenting, which keeps that vessel open with a small tube, and the modified Blalock-Taussig shunt (mBTS), which creates a surgical detour to route blood to the lungs. The study followed 86 infants treated at two hospitals in Thailand between 2017 and 2022, tracking how well the lung arteries (pulmonary arteries) grew over time and how often complications occurred.
This research suggests that PDA stenting led to faster early growth of the pulmonary arteries — the blood vessels supplying the lungs — within the first two months compared to the surgical shunt. However, by 12 months, one measure of pulmonary artery size (the Nakata index) had caught up and was similar between the two groups, though another measure (McGoon ratio) still showed a statistically significant difference favoring PDA stenting. Importantly, PDA stenting was associated with far fewer procedural complications: about 17% of PDA stenting patients experienced complications compared to nearly 58% of mBTS patients, making the complication risk more than three times higher with the surgical shunt. While fewer PDA stenting patients died during the study period, this difference did not reach statistical significance.
This research suggests that PDA stenting may offer advantages over the traditional surgical shunt in terms of earlier pulmonary artery growth and a lower rate of procedural complications in newborns with this heart condition. However, because this was a retrospective study — meaning researchers looked back at existing records rather than randomly assigning treatments — and because the two groups had different underlying heart diagnoses, caution is warranted in drawing firm conclusions. These findings add to a growing body of evidence supporting PDA stenting as a viable and potentially preferable first-stage treatment, but randomized studies would be needed to confirm these results.