Abstract

Pulmonary flow restrictors in congenital heart diseases: Procedural considerations, clinical outcomes, and future directions

Author(s): Raymond N. Haddad, Mohamed Kasem

The percutaneous endovascular pulmonary arterial banding technique currently relies on approved Microvascular Plugs (MVPs) from Medtronic. These manually created flow restrictors, known as Pulmonary Flow Restrictors (PFRs), can be effortlessly inserted via small diagnostic catheters, offering a minimally invasive treatment avenue for newborns and infants afflicted with life-threatening congenital and acquired heart diseases. Building on the pioneering efforts of Schranz and colleagues, we, together with various international centers have initiated transcatheter programs aimed at managing pulmonary over circulation, harmonizing pulmonary and systemic circulation, or enhancing interventricular interaction. Strategies centered on customized PFRs, with or without additional duct stenting, have demonstrated efficacy in facilitating delayed Norwood surgery or comprehensive Stage II operations. Additionally, in neonates with hypoplastic left hearts, these strategies have proven useful in delaying biventricular repair attempts until later infancy. Ultimately, these PFRs are safely extracted during corrective or palliative surgeries at a later developmental stage, ensuring the patient’s transition beyond the neonatal period in terms of both size and age. The advantages of this innovative procedure are manifold. It potential to shorten the intensive care stay and ensure a smoother recovery process for the patient. Bypassing the need for a sternotomy for a surgical Pulmonary Artery (PA) band spares the infant from additional trauma. Furthermore, the mortality rate associated with PFRs appears to be lower compared to traditional PA band operations. Moreover, the Infrastructural needs for carrying out this procedure are notably less demanding compared to cardiac surgery, making it feasible for implementation worldwide. Additionally, when the time for subsequent open-heart surgery arrives, the surgical removal of PFRs is straightforward for surgeons. Therefore, the utilization of PFR-based treatment represents a potential change of opinion. To ensure its successful adoption and widespread acceptance, consistency, and standardization in practice across centers is imperative. This review provides our opinion alongside a comprehensive overview of PFRs within the area of Congenital Heart Disease (CHD), covering indications, procedural considerations, and outcomes associated with PFR implantation. Additionally, it delves into emerging trends and future directions in pulmonary flow regulation, including advancements in device design, optimization of patient selection criteria, and ongoing research efforts to enhance the efficacy and safety of PFR therapy.