Evaluation of an antithrombotic surface coated flow diverter in rabbit model

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 flow diverter(BSCFD) would have less acute thrombus formation and better endothelialization on the device surface compared to uncoated flow diverter. An antithrombotic surface coated FD(BSCFD) was developed. Acute clot formation and chronic endothelialization over the device were assessed in 8 rabbit models comparing to 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 BSCFD and PFD using Kendall coefficient of rank correlation. Parent artery and branch artery were patent on DSA in 8 BSCFDs and 6 PFDs. There was 1 intra-stent thrombosis in PFDs at 2 hours and 1 intra-stent stenosis in PFD at 1 month. SEM at 2 hours showed that large amount of blood cells adhered to the surface of all 4 PFDs, and no blood cells were found on the surface of all 4 BSCFDs. At SEM and histological analysis of 1 month, there were less inflammation(Kendall's Tau-B=-0.818, p＝0.022), less vessel wall injury（Kendall's Tau-B=-0.764, p＝0.032）and better endothelialization(Kendall's Tau-B=0.818, p＝0.022) in BSCFDs. In the rabbit model, the BSCFD is associated with less thrombus formation at acute stage, less inflammation, less vessel injury and better endothelialization on the device surface compared to the PFD.