Impact of ductal stenting on pulmonary artery reconstruction in patients with duct-dependent congenital heart diseases-an institutional experience

Comparing flow and pulmonary artery growth post-patent ductus arteriosus stenting in patients with ductal-dependent pulmonary flow using 4D magnetic resonance imaging

Aims

The 4D magnetic resonance imaging (4D-flow MRI) provides a qualitative and quantitative assessment of cardiovascular structures and processes. 4D-flow MRI was used to study pulmonary flow in post-patent ductus arteriosus (PDA) stent insertion in duct-dependent pulmonary flow neonates at baseline (PDA stent insertion) and after 6 months, and also, to evaluate the effect of flow dynamics on the growth of pulmonary arteries (PAs).

Methods and results

This prospective observational study included neonates with ductus arteriosus-dependent pulmonary circulation who underwent ductal stenting between June 2021 and November 2022. Cardiac 4D-flow MRI and magnetic resonance angiography were conducted in two phases; after the deployment of the PDA stent during the neonatal period and after 6 months from stent deployment. Eight neonates were recruited, but only five completed both scans. A total of 10 PAs were evaluated during each phase. The median left PA (LPA) and right PA (RPA) diameters and indexed flow for LPA and RPA were evaluated. The growth rate of LPA was observed to be lower than that of RPA (percentage diameter increase: 74 vs. 153%). LPA Z-score was lower than RPA. Indexed flow in both LPA and RPA showed a reduction in the 6-month scan, which was consistent with reduced stent patency.

Conclusion

4D-flow cardiac MRI showed different growth rates and reduced flow between LPA and RPA post-PDA stent. These insights can aid in future management decisions.

Ductus arteriosus morphology in duct-dependent pulmonary circulation: CT classification and pattern in different ventricular morphology

BACKGROUND

The objective was to study the ductus arteriosus morphology in duct-dependent pulmonary circulation and its pattern in different ventricle morphology using CT angiography.

METHOD

From January 2013 to December 2015, patients aged 6 months and below with duct-dependent pulmonary circulation underwent CT angiography to delineate the ductus arteriosus origin, tortuosity, site of insertion, and pulmonary artery anatomy. The ductus arteriosus were classified into type I, IIa, IIb, and III based on its site of origin, either from descending aorta, distal arch, proximal arch, or subclavian artery, respectively.

RESULTS

A total of 114 patients and 116 ductus arteriosus (two had bilateral ductus arteriosus) were analysed. Type I, IIa, IIb, and III ductus arteriosus were seen in 13 (11.2 %), 71 (61.2%), 21 (18.1%), and 11 (9.5%), respectively. Tortuous ductus arteriosus was found in 38 (32.7%), which was commonly seen in single ventricular lesions. Ipsilateral and bilateral branch pulmonary artery stenosis was seen in 68 (59.6%) and 6 (5.3%) patients, respectively. The majority of patients with pulmonary atresia intact ventricular septum had type I (54.4%) and non-tortuous ductus arteriosus, while those with single and biventricular lesions had type II ductus arteriosus (84.9% and 89.7%, respectively). Type III ductus arteriosus was more common in biventricular lesions (77.8%).

CONCLUSIONS

Ductus arteriosus in duct-dependent pulmonary circulation has a diverse morphology with a distinct origin and tortuosity pattern in different types of ventricular morphology. CT may serve as an important tool in case selection and pre-procedural planning for ductal stenting.

Feasibility, safety, and efficacy of iron bioresorbable scaffold in neonates with duct-dependent pulmonary circulation

Introduction:

Bioresorbable stent has the theoretical advantage in the pediatric age group; however, experience in the literature is very limited.

Objectives:

This pilot study sought to evaluate the feasibility, safety, and performance of iron bioresorbable scaffold (IBS Angel™) as short-term palliation in lesions with noncomplex patent ductus arteriosus (PDA).

Materials and Methods:

Nine neonates with duct dependent but dual-source pulmonary blood flow (PBF) were included. Major stent-related complications, in-hospital course, stent patency up to 6 months, and unplanned re-interventions were studied, as well the percentage of stent material resorbed in patients in whom the stents were explanted at the surgery.

Results:

IBS Angel™ was successfully implanted in all nine patients (mean weight range 3.4 ± 0.4 kg). Six were pulmonary atresia with an intact ventricular septum and 1 critical pulmonary stenosis patients where PDA stenting was done together or after balloon dilation. The mean procedure and fluoroscopy times were 89 ± 39 min and 16.3 ± 6.9 min, respectively. There were no major complications such as stent thrombosis or embolization and there were no in-hospital deaths. Post procedure overshunting and prolonged ventilatory support was a prominent feature. The median ventilation days was 3 (1–11 days). One patient died after 1 month due to respiratory syncytial virus pneumonia at the referring hospital. At 6 months follow-up, four had patent stents and four had blocked or restrictive stent flow. One patient received re-stenting at 4 months for restrictive stent flow. In three patients where microcomputed tomography of explanted stent was available, resorption of iron was 15% at 6 months and >65% at 16 months.

Conclusions:

Ductal stenting with IBS Angel™ is feasible and safe in selected patients. Because of early luminal loss, its use may be recommended for lesions with dual-source PBF with noncomplex PDA morphology that requires a short duration of palliation.