Pulmonary artery growth after arterial duct stenting in completely duct-dependent pulmonary circulation

Stenting of the Patent Ductus Arteriosus

Since PDA stenting was first attempted in the early 1990s, significant technical advancements have improved outcomes and some centers have even transitioned to exclusive PDA stenting for all infants with duct-dependent pulmonary circulation. In addition to its use in infants with duct-dependent pulmonary circulation, PDA stenting has also been adapted as a percutaneous palliative option for suprasystemic pulmonary arterial hypertension and as a component of the hybrid procedure. In this article, the authors aim to review indications and outcomes for PDA stenting, describe the procedure, and discuss future directions.

Comparison of ductus stent versus surgical systemic-to-pulmonary shunt as initial palliation in patients with univentricular heart

OBJECTIVES

In this study, we aimed to compare infants with univentricular hearts who underwent an initial ductus stenting to those receiving a surgical systemic-to-pulmonary shunt (SPS).

METHODS

All infants with univentricular heart and ductal-dependent pulmonary blood flow who underwent initial palliation with either a ductus stenting or a surgical SPS between 2009 and 2022 were reviewed. Outcomes were compared after ductus stenting or SPS including survival, probability of re-interventions and the probability to reach stage II palliations.

RESULTS

A total of 130 patients were evaluated, including 49 ductus stenting and 81 SPSs. The most frequent primary diagnosis was tricuspid atresia in 27, followed by pulmonary atresia with intact ventricular septum in 19 patients. There was comparable hospital mortality (2.0% stent vs 3.7% surgery, P = 0.91) between the groups, but shorter intensive care unit stay (median 1 vs 7 days, P < 0.01) and shorter hospital stay (median 7 vs 17 days, P < 0.01) were observed in patients with initial ductus stenting, compared to those with SPS. However, acute procedure-related complications were more frequently observed in patients with ductus stenting, compared with those with SPS (20.4 vs 6.2%, P = 0.01), and 10 patients needed a shunt procedure after the initial ductus stent. The cumulative incidence of reaching stage II was similar between ductus stenting and SPS (88.0 vs 90.6% at 12 months, P = 0.735). Pulmonary artery (PA) index (median 194 vs 219 mm2/m2, P = 0.93) at stage II was similar between patients with ductus stenting and SPS. However, the ratio of the left to the right PA index [0.69 (0.45-0.95) vs 0.86 (0.51-0.84), P = 0.015] was higher in patients who reached stage II with surgical shunt physiology, compared with patients with ductus stent physiology.

CONCLUSIONS

After initial ductus stenting in infants with univentricular heart, survival is comparable and post-procedural recovery shorter, but more acute stent dysfunctions and lower development of left PA are observed, compared to acute shunt dysfunctions. The less invasive procedure and shorter hospital stay are at the expense of more stent reinterventions.

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.

Erratum: Stenting of the Patent Ductus Arteriosus: A Meta-analysis and Literature Review

[This corrects the article DOI: 10.1016/j.jscai.2022.100392.][This corrects the article DOI: 10.1016/j.jscai.2023.101051.].

Stenting of the Patent Ductus Arteriosus: A Meta-analysis and Literature Review

Background

Patent ductus arteriosus (PDA) stent placement and systemic-pulmonary surgical shunt procedure can both be performed as palliation for infants with duct-dependent pulmonary circulation. The aim of this meta-analysis and literature review was to compare outcomes and study populations between the 2 methods as well as review the technical considerations and complications of PDA stenting.

Methods

A systematic search was conducted using the PubMed database and meta-analysis was performed. Risk ratio and mean difference were used to compare the reported outcomes of studies across patients receiving PDA stent and surgical shunt.

Results

In total, 1094 patients from 8 comparative observational studies were included. The PDA stent group had a lower mortality rate and a shorter hospital length of stay than the systemic-pulmonary surgical shunt group, although at the expense of increased reintervention rates. There were higher proportions of patients with single-ventricle physiology and single-source pulmonary blood flow in the surgical shunt group.

Conclusions

PDA stenting appears to be a noninferior or possibly superior method of palliation for duct-dependent pulmonary circulation compared with systemic-pulmonary surgical shunt, recognizing, however, that patients receiving surgical shunt more often had single-ventricle physiology or single-source pulmonary blood flow in this meta-analysis.

Comparison of Patent Ductus Arteriosus Stent and Blalock-Taussig Shunt as Palliation for Neonates with Sole Source Ductal-Dependent Pulmonary Blood Flow: Results from the Congenital Catheterization Research Collaborative

Patent ductus arteriosus (PDA) stenting is an accepted method for securing pulmonary blood flow in cyanotic neonates. In neonates with pulmonary atresia and single source ductal-dependent pulmonary blood flow (SSPBF), PDA stenting remains controversial. We sought to evaluate outcomes in neonates with SSPBF, comparing PDA stenting and surgical Blalock-Taussig shunt (BTS). Neonates with SSPBF who underwent PDA stenting or BTS at the four centers of the Congenital Catheterization Research Collaborative from January 2008 to December 2015 were retrospectively reviewed. Reintervention on the BTS or PDA stent prior to planned surgical repair served as the primary endpoint. Additional analyses of peri-procedural complications, interventions, and pulmonary artery growth were performed. A propensity score was utilized to adjust for differences in factors. Thirty-five patients with PDA stents and 156 patients with BTS were included. The cohorts had similar baseline characteristics, procedural complications, and mortality. Interstage reintervention rates were higher in the PDA stent cohort (48.6% vs. 15.4%, p < 0.001).

Factors Influencing Reintervention Following Ductal Artery Stent Implantation for Ductal-Dependent Pulmonary Blood Flow: Results From the Congenital Cardiac Research Collaborative

BACKGROUND

Stenting of the patent ductus arteriosus (PDA) is an established palliative option for infants with ductal-dependent pulmonary blood flow. Following initial palliation, reintervention on the PDA stent is common, but risk factors have not been characterized.

METHODS

Infants with ductal-dependent pulmonary blood flow palliated with PDA stent between 2008 and 2015 were reviewed within the Congenital Cardiac Research Collaborative. Rates and risk factors for reintervention were analyzed.

RESULTS

Among 105 infants who underwent successful PDA stenting, 41 patients (39%) underwent a total of 53 reinterventions on the PDA stent, with all but one occurring within 6 months of the initial intervention. Stent redilation constituted the majority of reintervention (n=35; 66%) followed by additional stent placement (n=11; 21%) and surgical shunt placement (n=7; 13%). The majority of reintervention was nonurgent, and there were no deaths during the reintervention procedure. All but one reintervention occurred within 6 months of the initial procedure. On univariate analysis, risk factors for reintervention included anticipated single-ventricle physiology, lack of prior balloon pulmonary valvuloplasty, use of drug-eluting stent, and increased ductal tortuosity.

CONCLUSIONS

In infants with ductal-dependent pulmonary blood flow palliated with PDA stent implantation, reintervention is common, can be performed safely, and is associated with both anatomic/procedural factors and anticipated final physiology.

Right Ventricular Outflow Tract Stenting as Palliation of Critical Tetralogy of Fallot: Techniques and Results

Background. Despite current trends toward early primary repair, the surgical systemic-to-pulmonary shunt is still considered the first-choice palliation in patients with critical tetralogy of Fallot (TOF) and duct-dependent pulmonary circulation unsuitable for primary repair. However, stenting of the right ventricular outflow tract (RVOT) is nowadays emerging as an effective alternative to surgical palliation in selected patients. Methods and results. RVOT stenting is usually performed from a venous route, either femoral or, in selected cases, the right internal jugular vein. Less frequently, mostly in pulmonary infundibular/valvar atresia, this procedure can be performed using a hybrid surgical/interventional approach by surgical exposure of the RVOT, puncture of the atretic valve, and stent deployment under direct vision. The size and type of the most appropriate stent may be chosen, based on ultrasound measurements of the RVOT, to cover the right ventricular infundibulum completely and, at the same time, sparing the pulmonary valve, unless significant pulmonary valve annulus hypoplasia and/or supra-valvular stenosis is a significant component of the obstruction. In the large series so far published, early mortality of RVOT stenting is less than 2%, comparing favourably with either Blalock-Thomas-Taussig shunt or early primary repair. In addition, morbidity and clinical sequelae of this approach do not significantly differ from surgical palliation, even if RVOT stenting shows lesser durability and a higher rate of trans-catheter re-interventions over a mid-term follow-up. Finally, similar but more balanced pulmonary artery growth than surgical palliation following RVOT stenting is reported over a mid-term follow-up. Conclusions. RVOT stenting is a technically feasible, well-tolerated, and effective palliation in critical TOF. This approach is cost-effective with respect to surgical palliation either in high-risk neonates or whenever a short-term pulmonary blood flow source is anticipated due to the early surgical repair. It effectively increases pulmonary blood flow, improves arterial saturation, and promotes balanced pulmonary artery growth over a mid-term follow-up.

Staged Repair of Van Praagh Truncus Type A3

Van Praagh (VP) A3 variant of truncus arteriosus (or common arterial trunk) is defined by only one pulmonary artery (usually the right) originating from the common trunk, while the other lung is supplied either by collaterals or a pulmonary artery arising from the aortic arch. This report describes a staged approach to manage a VP-A3 variant truncus arteriosus with ductal origin of the left pulmonary artery (LPA), a hypoplastic right pulmonary artery, and cyanosis. Initially, the ductal portion of the proximal LPA was stented with a Resolute Onyx drug-eluting stent. The pulmonary arteries grew and at four months of age had an acceptable McGoon ratio and Nakata index. The patient then underwent repair which included unifocalization of the branch pulmonary arteries, closure of the ventricular septal defect, and placement of a right ventricle-to-pulmonary artery homograft conduit.

Interventional Treatment of Cardiac Emergencies in Children with Congenital Heart Diseases

Cardiac emergencies in children represent an extremely important issue in medical practice. In general, interventional treatment could be optional in many situations, however it can be indicated in emergency conditions. There are many diseases at pediatric age that can benefit from interventional treatment, thus reducing the surgical risks and subsequent complications. Balloon atrioseptostomy, patent ductus arteriosus (PDA) closure, percutaneous or hybrid closure of a ventricular septal defect, pulmonary or aortic valvuloplasty, balloon angioplasty for aortic coarctation, implantation of a stent for coarctation of the aorta, for severe stenosis of the infundibulum of the right ventricle, or for PDA correction are among the procedures that can be performed in emergency situations. This review aims to present the current state of the art in the field of pediatric interventional cardiology.

Anesthesia for high-risk procedures in the catheterization laboratory

Recent advances in catheterization and imaging technology allow for more complex procedures to be performed in the catheterization laboratory. A number of lesions are now amenable to a percutaneous procedure, eliminating or at least postponing the need for a surgical intervention. Due to the increase in the complexity of the procedures performed, the involvement of anesthesiologists and their close collaboration with the interventional cardiologists have increased. It is important to understand the physiology and pathophysiology of the patients and to anticipate the plans and the potential complications in order to manage them. We are witnessing a rise in the number of complex interventions in newborns and infants, such as balloon valvotomy (critical aortic stenosis, pulmonary stenosis), radio frequency perforation (of pulmonary atresia and intact ventricular septum), right ventricular outflow tract stenting (in Tetralogy of Fallot), ductal stenting (in some ductus-dependent pulmonary circulation), and combined with a surgical procedure (hybrid procedure for hypoplastic left heart syndrome). Multiple registries have been created in order to understand and improve outcomes of patients with congenital heart disease undergoing catheterization procedures and to develop performance and quality metrics, from which data regarding anesthetic-related risks can be extrapolated. Experienced personnel and a multidisciplinary team approach with direct communication among the team members is a must to ensure anticipation and management of critical events when they occur.

Percutaneous axillary artery approach for ductal stenting in critical right ventricular outflow tract lesions in the neonatal period

OBJECTIVES

We aimed to assess the experience using a percutaneous axillary artery approach for insertion of arterial ductal stents in patients with critical right ventricular outflow tract lesions at two tertiary pediatric cardiology centers.

BACKGROUND

Patent ductus arteriosus stenting is an accepted palliative alternative to BT shunts for neonates with critical right heart lesions. Access to tortuous ductus' may be challenging via the femoral artery, whereas the carotid artery presents a low risk of stroke. Recently, the axillary artery has been utilized for access in these patients.

METHODS

We performed a retrospective review of neonates who underwent stent placement or angioplasty using percutaneous axillary artery approach at two tertiary care centers from October 2016 to November 2018. Medical records were reviewed to ascertain demographic, clinical, and outcome data.

RESULTS

Axillary artery access was performed in 20 patients (16 primary ductal stents and 4 re-interventions) at a median (IQR) procedural weight of 3.4 (3-3.9) kg. Median (IQR) procedural time was 110 (75-150) min. The median (IQR) ICU stay and intubation times were 14 (0-94) hr and 5 (0-40) hr, respectively. There were three access-related vascular complications which were managed conservatively with no long-term effects. Two patients subsequently died due to non-procedure related causes.

CONCLUSIONS

Ductal stenting via a percutaneous axillary artery approach is a viable option in neonates with critical right ventricular outflow tract lesions. This approach provides an additional access site for PDA stenting which may be utilized in patients with vertical duct morphology.

Recent advances in cardiac catheterization for congenital heart disease

The field of pediatric and adult congenital cardiac catheterization has evolved rapidly in recent years. This review will focus on some of the newer endovascular technological and management strategies now being applied in the pediatric interventional laboratory. Emerging imaging techniques such as three-dimensional (3D) rotational angiography, multi-modal image fusion, 3D printing, and holographic imaging have the potential to enhance our understanding of complex congenital heart lesions for diagnostic or interventional purposes. While fluoroscopy and standard angiography remain procedural cornerstones, improved equipment design has allowed for effective radiation exposure reduction strategies. Innovations in device design and implantation techniques have enabled the application of percutaneous therapies in a wider range of patients, especially those with prohibitive surgical risk. For example, there is growing experience in transcatheter duct occlusion in symptomatic low-weight or premature infants and stent implantation into the right ventricular outflow tract or arterial duct in cyanotic neonates with duct-dependent pulmonary circulations. The application of percutaneous pulmonary valve implantation has been extended to a broader patient population with dysfunctional ‘native’ right ventricular outflow tracts and has spurred the development of novel techniques and devices to solve associated anatomic challenges. Finally, hybrid strategies, combining cardiosurgical and interventional approaches, have enhanced our capabilities to provide care for those with the most complex of lesions while optimizing efficacy and safety.

Emergency transcatheter closure of a stented PDA in a patient with pulmonary atresia and intact ventricular septum: be ready for the unexpected!

Patients with congenital heart disease and duct‐dependent pulmonary circulation can undergo stenting of the patent ductus arteriosus (PDA). This case shows that, due to the physiological changes occurring after stent implantation, sometimes it is necessary to close the stented PDA rather than to redilate it.

Stenting the complex patent ductus arteriosus in tetralogy of Fallot with pulmonary atresia: challenges and outcomes

Patent ductus arteriosus (PDA) stenting has gained acceptance for palliation in cyanotic congenital heart disease. The PDA in tetralogy of Fallot with pulmonary atresia (ToF-PA) arises, in the left aortic arch, from underneath the arch and connects to the proximal left pulmonary artery, often resulting in stenosis. The PDA is usually elongated and tortuous, making stent implantation challenging. Shorter duration of palliation, aggravation of branch pulmonary artery stenosis resulting in poor growth and difficulty at surgery makes ductal stenting controversial. Access via the carotid and axillary artery reduces complexity of the procedure and improves success, with recent data demonstrating good pulmonary artery growth. Advances in bioresorbable stents offer future promise and will likely resolve some controversies surrounding PDA stenting in ToF-PA.

Fate of Duct-Dependent, Discontinuous Pulmonary Arteries After Arterial Duct Stenting

Significant and balanced PA growth following arterial duct (AD) stenting has already been consistently reported in literature. However, to date, no data are available about the role of this approach as palliation of congenital heart disease with a duct-dependent discontinuous pulmonary artery (dPA). The aim of this study was to evaluate the fate of a dPA of ductal origin following trans-catheter AD stabilization. Angiographic PA evaluation was performed in seven patients submitted to neonatal AD stenting as palliative recruitment of dPA. Five patients showed discontinuity of one PA, while two patients had both PAs served by bilateral ducts. PA growth was evaluated as per the Nakata index, McGoon ratio as well as dPA (n = 9) versus heart-dependent PA (hPA; n = 5) size and z-score changes. AD stabilization was performed using coronary stents dilated to 3.2 ± 0.3 mm (median 3.4), with significant increase of O₂ saturation (from 83 ± 11 to 95 ± 5%, p < 0.02). Control angiography was performed 5.1 ± 2.8 months (median 6 months) after duct stenting, showing significant growth of the dPA (from 3.7 ± 1.0 to 7.6 ± 2.7 mm, p < 0.001; z-score from -0.7 ± 1.4 to 1.7 ± 2.2, p < 0.01). A trend toward better growth of the dPA as compared with the hPA was found (117 ± 87 vs. 54 ± 34%, p = NS). The final vessel size was still significantly different between the groups (dPA 7.6 ± 2.7 vs. hPA 11.9 ± 3.4 mm, p = 0.02), although the final z-score value did not significantly differ (dPA 1.7 ± 2.2 vs. hPA 3.8 ± 0.9 mm, p = NS). In conclusion, percutaneous AD stenting is effective in promoting a significant catch-up growth of duct-dependent dPA, being, therefore, advisable as a reliable alternative to surgical palliation.

Hemodynamics of patient-specific aorta-pulmonary shunt configurations

Optimal hemodynamics in aorta-pulmonary shunt reconstruction is essential for improved post-operative recovery of the newborn congenital heart disease patient. However, prior to in vivo execution, the prediction of post-operative hemodynamics is extremely challenging due to the interplay of multiple confounding physiological factors. It is hypothesized that the post-operative performance of the surgical shunt can be predicted through computational blood flow simulations that consider patient size, shunt configuration, cardiac output and the complex three-dimensional disease anatomy. Utilizing only the routine patient-specific pre-surgery clinical data sets, we demonstrated an intelligent decision-making process for a real patient having pulmonary artery atresia and ventricular septal defect. For this patient, a total of 12 customized candidate shunt configurations are contemplated and reconstructed virtually using a sketch-based computer-aided anatomical editing tool. Candidate shunt configurations are evaluated based on the parameters that are computed from the flow simulations, which include 3D flow complexity, outlet flow splits, shunt patency, coronary perfusion and energy loss. Our results showed that the modified Blalock-Taussig (mBT) shunt has 12% higher right pulmonary artery (RPA) and 40% lower left pulmonary artery (LPA) flow compared to the central shunt configuration. Also, the RPA flow regime is distinct from the LPA, creating an uneven flow split at the pulmonary arteries. For all three shunt sizes, right mBT innominate and central configurations cause higher pulmonary artery (PA) flow and lower coronary artery pressure than right and left mBT subclavian configurations. While there is a trade-off between energy loss, flow split and coronary artery pressure, overall, the mBT shunts provide sufficient PA perfusion with higher coronary artery pressures and could be preferred for similar patients having PA overflow risk. Central shunts would be preferred otherwise particularly for cases with very low PA overflow risk.