First-in-man pulmonary artery stenting in children using the Bentley® BeGrow™ stent system for newborns and infants.

BACKGROUND: Stent implantation into growing vessels is a common treatment option in infants and children with congenital heart disease (CHD) and corresponding vessel lesions. After stent implantation in small children, repetitive stent redilations are frequently necessary to accommodate for somatic growth. Until now, all available stents have limited final expansion diameters. MATERIAL AND RESULTS: The new Bentley BeGrow™ stent system for newborns and infants is a L605 cobalt­chromium, pre-mounted, balloon expandable stent, which is compatible with a 4 French sheath and 0.014 inch guide wire thus allowing implantation in small vessels (4-6 mm). It offers a new, unique stent design that allows post-dilation steps up to Ø11.5 mm. While re-dilating up to Ø11.5 mm this new stent maintains radial force and shows uniform expansion with only minimal foreshortening. Predetermined breaking points allow the stent struts to break in a controlled manner when exceeding a diameter of 11.5 mm. Residual radial force maintains even after stent opening due to spiral arrangement of the predetermined breaking points. The 2 first-in-man pulmonary artery stent implantations in a newborn with univentricular circulation and a toddler with biventricular circulation are reported as part of the currently performed licencing trial (ClinicalTrials.govNCT03287024). CONCLUSION: The low-profile BeGrow™ stent system offers new treatment options for transcatheter stent implantations in newborns and infants. In our first experience, it can be effectively implanted. Longer follow-up will evaluate multiple, stepwise redilations and controlled stent strut breakage, which have the potential to accommodate for somatic vessel growth and/or subsequent implantation of larger stents.