Preprocedural three-dimensional planning aids in transcatheter ductal stent placement: A single-center experience

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.

Clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: pediatric congenital heart disease conditions

BACKGROUND

The use of medical 3D printing (focusing on anatomical modeling) has continued to grow since the Radiological Society of North America's (RSNA) 3D Printing Special Interest Group (3DPSIG) released its initial guideline and appropriateness rating document in 2018. The 3DPSIG formed a focused writing group to provide updated appropriateness ratings for 3D printing anatomical models across a variety of congenital heart disease. Evidence-based- (where available) and expert-consensus-driven appropriateness ratings are provided for twenty-eight congenital heart lesion categories.

METHODS

A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with pediatric congenital heart disease indications. Each study was vetted by the authors and strength of evidence was assessed according to published appropriateness ratings.

RESULTS

Evidence-based recommendations for when 3D printing is appropriate are provided for pediatric congenital heart lesions. Recommendations are provided in accordance with strength of evidence of publications corresponding to each cardiac clinical scenario combined with expert opinion from members of the 3DPSIG.

CONCLUSIONS

This consensus appropriateness ratings document, created by the members of the RSNA 3DPSIG, provides a reference for clinical standards of 3D printing for pediatric congenital heart disease clinical scenarios.

Role of Cardiac CTA to Evaluate Branch Pulmonary Artery Stenosis and Ductal Insertion Pattern in Right-Sided Congenital Heart Defects

There is limited experience in evaluating abnormal ductus arteriosus (DA) insertion pattern by contrast-enhanced cardiac computed tomography (cardiac CT) in patients with right-sided obstructive cardiac defects. Retrospective review of 38 infants with right-sided obstructive cardiac defects who underwent a preoperative cardiac CT between 2016 and 2021. We reviewed the types of cardiac lesions, patterns of ductal insertion, frequency of pulmonary artery (PA) stenosis requiring intervention, total dose length product (DLP), and effective radiation dose. Of 38 infants, 45% were female, the median gestational age and weight were 37 (range 34-40) weeks and 2.95 (range 2-4) kg. The most common pathologies were pulmonary atresia with ventricular septal defect (24%) and tetralogy of Fallot (24%). The abnormal ductal insertion patterns were DA inserting into the left PA in 39%, DA bifurcating into branch PA in 32%, and DA inserting into the right PA in 13%. Of the 38 infants, 76% developed branch PA stenosis requiring intervention. Among patients with abnormal DA insertion, 44% required branch PA arterioplasty during their index surgery compared to 17% without abnormal DA insertion. Regardless of the type of abnormal DA insertion, 67% developed bilateral branch PA stenosis over time. The mean DLP was 8 mGy-cm and the mean calculated effective radiation dose was 0.312 mSv. The utilization of contrast-enhanced cardiac CT in infants with right-sided obstructive heart defects can offer crucial insights into abnormal ductus arteriosus insertion patterns. This information is valuable for effective procedure planning and for monitoring the development of branch pulmonary artery stenosis.

Computed tomography for aortic assessment in children

Because the aorta is the major vessel of the body, basic knowledge of aortic pathology is essential to the pediatric imager. This review divides aortic pathology into anatomical (e.g., congenital abnormalities) and acquired (e.g., vasculitis, trauma) entities, providing a brief description of pathology, technical considerations in CT acquisition and processing, and some pearls and pitfalls of interpretation. The objective of this paper is to familiarize general pediatric imagers with imaging features of common as well as high-impact aortic pathology on CT and prepare them for acquisition and reporting.

Short- and medium-term outcomes for patent ductus arteriosus stenting in neonates ≤2.5 kg with duct-dependent pulmonary circulation

BACKGROUND

Morbidity with surgical systemic-to-pulmonary artery shunting (SPS) in infants ≤2.5 kg has remained high. Patent ductus arteriosus (PDA) stenting may be a valid alternative. The objective of this study is to evaluate outcomes following PDA stenting in patients ≤2.5 kg from four large tertiary centers.

METHODS

Retrospective review of all neonates ≤2.5 kg with duct-dependent pulmonary circulation who underwent PDA stenting. Procedural details, pulmonary arterial growth, reinterventions, surgery type, and outcomes were assessed.

RESULTS

PDA stents were implanted in 37 of 38 patients attempted (18 female) at a median procedural weight of 2.2 kg (interquartile range [IQR], 2-2.4 kg). Seven patients (18%) had a genetic abnormality and 16 (42%) had associated comorbidities. The median intensive care unit stay was 4 days (IQR, 2-6.75 days), and the median hospital stay was 20 days (IQR, 16-57.25). One patient required a rescue shunt procedure, with three others requiring early SPS (<30 days postprocedure). Twenty patients (54%) required reintervention with either balloon angioplasty, restenting, or both. At 6-month follow-up, right pulmonary artery growth (median z-score -1.16 to 0.01, p = 0.05) was greater than the left pulmonary artery (median z-score -0.9 to -0.64, p = 0.35). Serious adverse effects (SAEs) were seen in 18% (N = 7) of our cohort. One patient developed an SAE during planned reintervention There were no intraprocedural deaths, with one early procedure-related mortality, and three interstage mortalities not directly related to PDA stenting.

CONCLUSIONS

PDA stenting in infants ≤2.5 kg is feasible and effective, promoting pulmonary artery growth. Reintervention rates are relatively high, though many are planned to allow for optimal growth before a definitive operation.

Transcatheter Approaches to Palliation for Tetralogy of Fallot

To this day, controversy still exists regarding the optimal method to treat symptomatic neonates and infants with Tetralogy of Fallot (TOF). Symptomatic (severely cyanotic or ductal dependent) infants with TOF can undergo either a staged repair approach (consisting of initial palliation followed by complete repair) or primary repair. Traditionally, initial palliative procedures have been surgical, for example placement of a Blalock-Taussig-Thomas (BTT) shunt. Recent advances in technology have facilitated the introduction of catheter-based procedures as palliative techniques, for example, patent ductus arteriosus (PDA) stenting and right ventricular outflow tract (RVOT) stenting as more durable solutions than balloon pulmonary valvuloplasty (BPV). In this article, we discuss the rationale for these procedures, technical aspects of these procedures and outcomes data compared to traditional surgical procedures. Recent data have suggested that RVOT and PDA stenting procedures offer many advantages over traditional surgical palliative procedures as palliative methods in this patient population. This comes at a cost of increased reintervention burden, which may be considered part of the overall treatment strategy in smaller neonates and can be minimized with a focus on technical aspects and overall treatment strategies. Advanced surgical techniques are required at the eventual complete repair to negotiate removal of stent material and pulmonary artery reconstruction in some instances. Further adoption of catheter based palliative procedures for infants with symptomatic TOF has the potential to tip the outcomes towards favoring a staged approach, particularly in high-risk infants.

Role of Cross-Sectional Imaging in Pediatric Interventional Cardiac Catheterization

Management of congenital heart disease (CHD) has recently increased utilization of cross-sectional imaging to plan percutaneous interventions. Cardiac computed tomography (CT) and cardiac magnetic resonance (CMR) imaging have become indispensable tools for pre-procedural planning prior to intervention in the pediatric cardiac catheterization lab. In this article, we review several common indications for referral and the impact of cross-sectional imaging on procedural planning, success, and patient surveillance.

Three-dimensional modeling of the mitral valve for surgical planning in a pediatric patient: A case-based discussion of the technical challenges of segmentation and printing from 3D transthoracic echocardiographic datasets

Abnormal atrioventricular valve present great challenges to the surgeon in achieving a successful repair, and thus present a great opportunity for enhanced 3D imaging to guide pre- and intra-operative management. Spatial and temporal resolution of 3D echocardiography enables 3D printing of valve morphology. However, non-linearity, angle dependence, speckle, blur, and resampling complicate segmentation compared to computed tomography (CT) and magnetic resonance imaging (MRI). A case of complex mitral valve disease in a pediatric patient is therefore presented to illustrate the technical challenges of segmentation and 3D printing from echocardiographic data.

Pre-procedural CT imaging aids neonatal PDA stenting for ductal-dependent pulmonary blood flow with reduction in overall procedural morbidity

Patent ductus arteriosus stenting for ductal-dependent pulmonary blood flow is a technically challenging neonatal procedure to maintain a stable pulmonary circulation. Pre-procedural computed tomography imaging aids in outlining ductal origin, insertion, size, course and curvature. Computed tomography imaging may add value to procedural outcomes and reduce overall procedural morbidity in neonatal patent ductus arteriosus stenting. We conducted a single centre retrospective chart review of neonates with ductal-dependent pulmonary blood flow who underwent patent ductus arteriosus stenting between January 1, 2014 and June 31, 2020. We compared patients variables between patients who underwent pre-procedural computed tomography imaging to those who did not. A total of 64 patients were referred for patent ductus arteriosus stenting with 33 (52%) obtaining pre-procedural computed tomography imaging. Average age [19 days; range 1-242 days (p = 0.85)] and weight [3.3 kg (range 2.2-6.0 kg; p = 0.19)] was not significantly different between the groups. A diagnosis of pulmonary atresia was made in 42 out of 64 (66%) patients prior to patent ductus arteriosus stenting. The cohort with pre-intervention computed tomography imaging had a significant reduction in the total number of access sites (1.2 versus 1.5; p = 0.03), contrast needed (5.9 versus 8.2 ml/kg; p = 0.008), fluoroscopy (20.7 versus 38.8 minutes; p = 0.02) and procedural time (83.4-128.4 minutes; p = 0.002) for the intervention. There was no significant difference in radiation burden between the groups (p = 0.35). Pre-procedural computed tomography imaging adds value by aiding interventional planning for neonatal patent ductus arteriosus stenting. A statistically significant reduction in the number of access sites, contrast exposure, as well as fluoroscopic and procedural time was noted without significantly increasing the cumulative radiation burden.

Technical Modifications for Ductal Stenting in Neonates with Duct-Dependent Pulmonary Circulation

The ductal stenting (DS) is currently an acceptable palliative treatment in newborns suffering with duct-dependent pulmonary circulation. However, this procedure remains technically a challenge in complex ductal morphology, which may eventually lead to detrimental outcomes. This review is mainly focused on pre-procedural planning, essential instruments and practical approaches for DS, and post-procedural care.