Article Text
Abstract
Background Flow-diverting stents (FDS) have revolutionized the treatment of intracranial aneurysms; however, their metallic structure induces thromboembolic complications and delays definitive healing. Several coating strategies have recently been introduced to improve FDS properties, such as the Shield coating to reduce thrombogenicity and the P8RI coating, which also focuses on stimulating endothelial cells for faster and enhanced arterial healing. This study aims to evaluate early neointimal growth over the FDS struts with these different surface modifications.
Methods Bare Silk Vista (bare-SV), P8RI Silk Vista (P8RI-SV), and Pipeline Vantage with shield technology (Shield-PV) were implanted in rabbits to treat elastase-induced aneurysms (n=6, 10 and 7, respectively) and in the aorta (n=6, 7 and 4, respectively). At 5 and 28 days, the devices were imaged with optical coherence tomography (OCT) to evaluate stent-coverage ratio (i.e. N struts covered by neointima/N total of struts). Histological correlation was also performed.
Results At day 28, a higher rate of complete/near-complete occlusion was achieved in the P8RI-SV (6/8, 75%) and Shield-PV (5/6, 83%; one Shield-PV thrombosed) groups compared to bare-SV (3/6, 50%; p=0.577). A total of 1072 cross-sectional OCT images were analyzed. Overall (aorta and aneurysm site) stent-coverage ratio at day 5 was significantly higher with P8RI-SV compared to both bare-SV and Shield-PV (Kruskal-Wallis p<0.0001, Dunn post-test p<0.0001 for both (bare-SV versus Shield-PV: p=0.485). At day 28, overall stent-coverage ratio increased in all groups and remained significantly higher with P8RI-SV compared to both bare-SV and Shield-PV (p<0.0001) (bare-SV versus Shield-PV: p=0.766; figure 1). Stent-coverage ratio was systematically higher for P8RI-SV at the aneurysm site and in the aorta and for each timepoint (p<0.001 all). Histological analysis confirmed that the struts of P8RI-SV were covered a well-organized neo-tissue at both early (day 5) and late (day 28) timepoints.
Conclusions In vivo, P8RI-SV demonstrated faster and higher rates of neointimal formation covering the FDS struts compared to bare-SV and shield-PV. These results confirm earlier and improved arterial healing with P8RI coating, which could potentially help to achieve higher occlusion rates and enable earlier discontinuation of antiplatelet therapy in clinical practice.
Disclosures J. Cortese: 1; C; Balt, Medtronic, Phenox, Microvention, SFNR French Society of Neuroradiology, SFR French Society of Radiology. G. Forestier: None. M. Baudouin: None. S. Bardet: None. F. Terro: None. M. Perrin: None. J. Mounier: None. C. Mounayer: 2; C; Balt. L. Spelle: 2; C; Medtronic, Stryker, Microvention, Balt, Phenox. A. Rouchaud: 2; C; Balt.