Introduction Flow diversion for aneurysm treatment has been widely used. Biomimetic surface modifications such as the phosphorylcholine polymer (Shield surface modification) aim to reduce thrombogenicity of these devices, and potentially the need for dual-antiplatelet therapy. How this modification affects endothelial growth remains unclear.

Aim of Study To investigate in-vivo the longitudinal healing of Pipeline Shield, Vantage Shield, and bare metal Pipeline Flex devices in vivo with the hypothesis that there would be no differences between modified and bare devices.

Methods The common carotid arteries of ten rabbits were implanted with the 3 FD-stents mentioned. All devices were imaged with high-frequency optical coherence tomography (HF-OCT) and angiography at implant,5,10,15 and 30 days to evaluate placement and tissue growth. At 30 days, the devices were explanted, and endothelial growth was assessed with scanning electron microscopy (SEM) at 5 locations along their length using a semi-quantitative score from 0 (no tissue growth) to 5 (complete coverage). An automated method was used to measure the average tissue growth thickness (ATGT) along the device based on the HF-OCT images.

Results At 5 days, no statistical difference of ATGT between devices was shown, with the Vantage having a slightly higher ATGT. At the remaining timepoints, there was no difference, or trend in ATGT between device types. On SEM, all devices scored at least a 4 or 5 at every location, and no differences were found between median or mean scores.

Conclusion Endothelial coverage is not affected by Shield surface modification nor the Vantage stent design.

Disclosure of Interest CZ, ME, RK: Nothing to disclose

VA, MG :Medtronic