Evaluation of an Antithrombotic Surface-Coated Flow Diverter in a Rabbit Model without Dual Antiplatelet Drugs

Flow diverters (FDs) carry the risk of thromboembolic complications associated with the device and bleeding complications associated with dual antiplatelet therapy. We hypothesize that an antithrombotic surface-coated FD (ASCFD) would have less acute thrombus formation and better endothelialization on the device surface compared with uncoated FD. A ASCFD was developed. Acute clot formation and chronic endothelialization over the device were assessed in 8 rabbit models compared with its prototype FD (PFD) at 2 hours and 1 month by scanning electron microscopy (SEM) and histologic images. Nonparametric score data, including thrombus, injury, endothelialization, adventitial inflammation, intramural bleeding, and intimal hyperplasia were compared between ASCFD and PFD using the Kendall coefficient of rank correlation. Parent artery and branch artery were patent on digital subtraction angiography in 8 ASCFDs and 6 PFDs. There was 1 intrastent thrombosis in PFDs at 2 hours and 1 intrastent stenosis in PFDs at 1 month. SEM at 2 hours showed that a large number of blood cells adhered to the surface of all 4 PFDs, and no blood cells were found on the surface of all 4 ASCFDs. At SEM and histologic analysis of 1 month, there was less inflammation (Kendall τ-B –0.818; P ＝ 0.022), less vessel wall injury (Kendall τ-B = –0.764; P ＝ 0.032), and better endothelialization (Kendall τ-B = 0.818; P ＝ 0.022) in ASCFDs. In the rabbit model, the ASCFD is associated with less thrombus formation at the acute stage, less inflammation, less vessel injury, and better endothelialization on the device surface compared with the PFD.