F. Canalejo-Codina et al. Preclinical evaluation of pediatric polymeric stents in a minimally invasive rabbit model. Materials Today Communications
F. Canalejo-Codina, M Cano-Morenilla, M Bonich-Aranda, A. López-Campillo, X. Yugueros, G. Mestres, M. Pegueroles, E.R. Edelman, A. A. García-Granada, M. Balcells. J. Martorell. Preclinical evaluation of pediatric polymeric stents in a minimally invasive rabbit model. Materials Today Communications 56 (2026) 116016. OPEN ACCESS.
Abstract
Stent implantation is standard treatment for pediatric aortic coarctation, but permanent metallic devices do not accommodate somatic growth, causing repeated interventions and long-term complications. Bioresorbable polymeric stents offer temporary support with progressive vascular adaptation, yet in vivo validation remains essential. This study evaluates the procedural performance and in vivo biocompatibility of a next-generation polymeric stent in a minimally invasive rabbit model. A microstructure-based auxetic (MBA) geometry fabricated from poly(L-lactide-co-ε-caprolactone) was optimized to a radial force of 0.98 N/mm at 0.55 maximum strain and implanted via a novel 6F femoral catheterization in New Zealand white rabbits, with solvent-cast direct-write (SCDW) polymeric and Cook Formula 418 metallic stents as controls. Of 24 animals, 22 received 39 stents, with follow-up at 30 min, 14 and 28 days. The implantation and explantation protocol proved feasible and reproducible. No MBA device was dislodged during delivery, vs 36.4% of SCDW devices (p = 0.004); migration did not differ between polymeric and metallic devices (p = 0.686). At 28 days, both platforms achieved complete endothelialization (5.00 ± 0.00), minimal vessel injury (0.33 ± 0.52) and preserved medial architecture. Strut integration was complete for MBA (5.00 ± 0.00) vs partial for SCDW (4.33 ± 0.82), and neointimal inflammation was minimal in both (MBA 1.00 ± 0.00; SCDW 1.17 ± 0.41). Transient mural thrombus at 14 days had resolved by 28 days. Neointimal area was comparable (MBA 2.44 ± 0.08 mm²; SCDW 2.24 ± 0.41 mm²), with higher stenosis in MBA arteries (32.72 ± 3.00% vs 20.85 ± 4.00%). These findings support the early biocompatibility of the MBA platform and validate the model for longitudinal assessment of pediatric vascular devices.
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