Recent advances in cardiac catheterization for congenital heart disease

Abstract

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.

Keywords: angiography; cardiac catheterization; heart.

Figure 1.. Rotational angiograms.

Panel A: a three-dimensional (3D)-rotational angiogram in a child with severe left pulmonary artery stenosis related to the retained ductal stent (arrow). The injection was in the bidirectional cavopulmonary connection. Panel B: this reconstruction from a 3D-rotational angiogram shows the relationships between vascular structures; in this case, left bronchial stenosis (star) is due to vascular compression (arrow) following previous arch reconstruction.

Figure 2.. Three-dimensional modeling.

The upper image is a three-dimensional model obtained from a magnetic resonance angiogram with the free wall of the right ventricle cut away revealing the location of the ventricular septal defect (VSD); the lower model, made from a soft pliable material, shows the appearance of the VSD as seen through a virtual incision in the right atrium, as would be seen by the surgeon.

Figure 3.. Hypoplastic pulmonary arteries and outflow stent.

Upper panels from right ventricular angiograms show the obstructive right ventricular outflow tract (^) in a newborn with Fallot’s tetralogy. The lower panels show stent implantation (*) to enlarge the outflow and improve pulmonary blood flow, relieving the cyanosis.

Figure 4.. Ductal stent.

The left panel details a stenotic arterial duct as it connects with the main pulmonary artery in a child with ductal-dependent pulmonary circulation. The right panel shows the appearance of the duct after the placement of a ductal stent to support the pulmonary blood flow.

Figure 5.. Percutaneous pulmonary valves for the large outflow tract.

The left panel is a picture of the Edwards Alterra™ stent, designed to be placed in the right ventricular outflow tract in patients after transannular patch repair for Fallot’s tetralogy. The nitinol stent hosing (seen in the photo) provides a landing zone for a 29 mm Sapien™ valve. The right panel is a photo of Medtronic’s Harmony™ valve. This valve stent design has porcine pericardial valve leaflets sewn into the nitinol framework.