Stents in Congenital Heart Disease: State of the Art and Future Scenarios

Stents are tubular meshed endoprostheses implanted mini-invasively through a transcatheter intervention to guarantee the patency of body conduits, mainly in cardiovascular applications. In pediatric cardiology, stenting has become an accepted procedure in the treatment of congenital heart disease (CHD) as an alternative to open-heart surgery. CHD refers to a range of defects affecting the heart's structure and function arising from abnormal development during pregnancy. While during fetal life, the presence of additional shunts allows for the establishment of parallel circulation and survival of gestation, CHD is not compatible with extrauterine life, and medical intervention is required soon after birth. This review aims to discuss the state of the art of stenting in CHD. Despite the severity of these pathologies, investment from the industry remains limited due to the restricted number of cases, and dedicated devices are still missing. As a consequence, commercially available adult stents are commonly exploited on an off-label basis in newborns without any optimization for the specific anatomy and required function. In this review, a classification of the available stents is provided, resuming the manufacturing technologies, materials, and geometrical aspects to obtain the target biomechanical performance. After analyzing the fetal circulation, different forms of CHD amenable to stenting are considered, collecting the stents currently adopted and discussing the clinical outcomes to outline the features of an ideal device.