Preclinical in vivo results of the new generation coated FRED Flow Diverter

BACKGROUND: The introduction of coatings on flow diverter stents (FD) marks a significant evolution in neurovascular intervention for aneurysm embolization. FDs represent a major innovation in the treatment of intracranial aneurysms by promoting endothelial healing and reconstructing the parent artery. FRED Omega is a new generation FD featuring a poly(2-methoxyethyl acrylate) (PMEA)-based surface modification designed to reduce thrombogenicity while maintaining endothelialization. This preclinical study assessed the biocompatibility and aneurysm occlusion efficacy of FRED Omega in a rabbit elastase aneurysm model. METHODS: Eight New Zealand white rabbits were implanted with FRED Omega across elastase-induced aneurysms and maintained on single antiplatelet therapy (SAPT). Angiography, cone-beam computed tomography, and optical coherence tomography (OCT) were used to evaluate device performance. Histology, environmental scanning electron microscopy (ESEM) and multiphoton microscopy analyses (MM) were conducted on explanted tissues. RESULTS: At day 28, 7 aneurysms (87.50%, 7/8) achieved complete or near-complete occlusion. All implants remained stable over the time study. All vessels were clear of thrombus with no flow abnormalities nor sign of intimal hyperplasia. OCT confirmed these data associated with good wall apposition for all stents (100.00%, 8/8). Histology and ESEM showed well-organized new tissue on each FD (100.00%, 8/8), compared to 75.00% for MM (6/8, 75.00%). Quantitative measurement of neointimal ratio was excellent with an average of 0.068. CONCLUSION: FRED Omega demonstrated promising preclinical performance with enhanced endothelialization and aneurysm occlusion in a validated animal model under SAPT.