The primary objective was to evaluate the trend of blood sirolimus concentrations in neonates following ductal stenting. The long-term outcomes and incidence of infections were also evaluated.

Prospective open-label observational study in a tertiary referral centre over a 1-year period. Serum sirolimus levels were estimated at 1 hour and 24hrs post-stent insertion followed by 7 days in neonates who underwent ductal stenting. The trend in sirolimus levels, incidence of infections, complications and outcomes following ductal stenting were studied.

Seven neonates with duct-dependent pulmonary circulation underwent ductal stenting at median age of 8.5 days and weight of 2.83kg. The average stent size was 3.5±0.4 mm, and average stent length was 16.3±5.1 mm. The mean sirolimus concentrations at 1 hour, 24 hours and 7 days were 41.3±6.9ng/ml, 15.4±7.1ng/ml and 3.1±0.85ng/ml respectively. Levels fell below therapeutic range for all patients by 7 days. Three patients had sepsis or necrotising enterocolitis, but responded well to antibiotics; 1 patient had aspiration related sudden death. There were no further events at a mean follow-up of 207 days, and 4 patients underwent elective surgery at 238 ± 81 days after ductal stenting.

This study demonstrates applicability of drug-eluting stents for ductal stenting in newborns. Drug-eluting stents with abluminal drug delivery are associated with high sirolimus levels in initial hours but rapidly taper to negligible levels within a week of implantation. Neonates with high pre-procedure likelihood of infection developed sepsis but responded well to conservative management. The patency of drug-eluting ductal stents is preserved over long-term follow-up.

In this retrospective single centre cohort study, hybrid PDA stenting was attempted in 11 patients with “flip technique”, between January 2020 and February 2021, and was successful in 10. Median age was 29 days (interquartile range 17.5–87) and mean weight 3.37 ± 1.23 kg. Mean fluoroscopy time was 13.58 ± 5.35 minutes, mean procedure time was 48.50 ± 22.5 minutes, and mean radiation dose was 1719.5 ± 1217.6 mGycm2. Mean time for cutdown was 9.9 ± 2.4 minutes and for haemostasis and suturing was 25.3 ± 11.0 minutes. Median duration of ventilation post-stenting was 26 hours (interquartile range 21–43.75). The median ICU stay post-procedure was 5 days (interquartile range 4–7.25) and mean hospital stay was 12 ± 6.3 days. On early follow-up, carotid patency was confirmed in all patients with colour Doppler, with no intravascular thrombi, narrowing, haematomas, or aneurysms noted. There were no complications secondary to vascular access. There was one early mortality, 27 days post-stenting, which was unrelated to the procedure.

This study adds to the limited literature on ductal stenting with carotid access and the flip technique. In our early experience, the hybrid carotid approach is an attractive alternative to percutaneous carotid puncture and has simplified a complex and challenging intervention, with good outcomes.