A novel iron bioresorbable scaffold: a potential strategy for pulmonary artery stenosis

A big diameter bioresorbable scaffold is expected to be used for treatment of vessel stenosis of children with congenital heart disease to adapt the growth characteristics of vessel of children and avoid the late adverse events of permanent stent implanted in children. However, it is challenging to fabricate a big diameter bioresorbable scaffold that is appropriate for percutaneous implantation with enough mechanical performance and can be smoothly delivered in children's small vessel. In this study, a novel iron big and bioresorbable Scaffold (BBS) for pulmonary artery stenosis of children with congenital cardiovascular diseases was fabricated and evaluated. The BBS was made of nitrided iron tube and processed by laser cutting and polishing. The testing results of radial strength, recoil, shortening, maximal expansion diameter and side-branch accessability illustrated the BBS has good mechanical performance. The animal study showed that the percentage of area stenosis of BBSs was 18.1 ± 8.6%, 20.2 ± 5.9% and 20.4 ± 6.1% at 28, 90 and 180 days after implantation in 17 rabbits, and no malposition, thrombus, dissection or tissue necrosis in the rabbit model was detected by micro-CT, STEM and histological examinations. An φ8 × 23 mm BBS was implanted into a 55-month-old child with left pulmonary stenosis, and multiple spiral CT was conducted. No lumen area loss appeared at 1- and 2-year follow-ups in this first-in-man study. It suggested that the BBS might be a new strategy for the therapy of pulmonary artery stenosis in children.