Background

Flow-diverter stents (FDSs) have revolutionised the treatment of intracranial aneurysms. However, associated dual antiplatelet treatment is mandatory. We investigated the biocompatibility of three proprietary antithrombogenic coatings applied to FDSs.

Methods

After Institutional Animal Care and Use Committee approval, four domestic juvenile female dogs (weight 19.9 ± 0.9 kg, mean ± standard deviation) were commenced on three different oral antiplatelet regimes: no medication (n = 1), acetylsalicylic acid (n = 2), and acetylsalicylic acid and clopidogrel (n = 1). Four p64 FDSs were randomly implanted into the subclavian, common carotid, and external carotid arteries of each dog, including both uncoated p64 stents and p64 stents coated with three different antithrombogenic hydrophilic coating (HPC). Angiography and histological examinations were performed. Wilcoxon/Kruskal-Wallis and ANOVA were used with p value < 0.05 considered as significant.

Results

Minimal inflammatory cell infiltration and no device-associated granulomatous cell inflammation were observed. No significant difference in adventitial inflammation (p = 0.522) or neointimal/medial inflammation (p = 0.384) between coated and uncoated stents as well as between the different stent groups regarding endothelial cell loss, surface fibrin/platelet deposition, medial smooth muscle cell loss, or adventitial fibrosis were found. Acute self-limiting thrombus formed on 6/16 implants (37.5%), and all of the thrombi were noted on devices implanted in the common or external carotid artery irrespective of the surface coating. Two of 12 p64 HPC-coated stents (16.7%) and 1/4 uncoated p64 stents (25%) showed severe or complete stenosis at delayed angiography.

Conclusions

In these preliminary in vivo experiments, HPC-coated p64 FDSs appeared to be biocompatible, without acute inflammation.

中文翻译：

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应用于p64分流器支架的三种不同涂层的体内犬科动物研究：初始生物相容性研究。

背景

分流支架（FDS）彻底改变了颅内动脉瘤的治疗方法。但是，必须同时进行双重抗血小板治疗。我们研究了三种适用于FDS的专有抗血栓形成涂层的生物相容性。

方法

在获得机构动物护理和使用委员会的批准后，以三种不同的口服抗血小板方案开始了四只家养的雌性幼犬（体重19.9±0.9千克，平均值±标准差）：无药物治疗（n  = 1），乙酰水杨酸（n  = 2） ，以及乙酰水杨酸和氯吡格雷（n  = 1）。将四只p64 FDS随机植入每只狗的锁骨下，颈总动脉和颈外动脉，包括未涂覆的p64支架和涂覆有三种不同抗血栓形成亲水涂层（HPC）的p64支架。进行血管造影和组织学检查。使用Wilcoxon / Kruskal-Wallis和ANOVA，p值<0.05被认为是显着的。

结果

观察到最小的炎症细胞浸润，未观察到与装置相关的肉芽肿细胞炎症。 涂层和未涂层​​支架之间以及不同支架组之间的外膜炎症（p  = 0.522）或新内膜/中间炎症（p = 0.384）均无显着差异，涉及内皮细胞损失，表面纤维蛋白/血小板沉积，内侧平滑肌细胞损失或发现外膜纤维化。急性自限性血栓形成在6/16植入物上（37.5％），所有血栓都在植入颈总动脉或颈外动脉的器械上发现，与表面涂层无关。12个p64 HPC涂层支架中的两个（16.7％）和1/4个未涂层的p64支架（25％）在延迟血管造影时显示出严重或完全狭窄。

结论

在这些初步的体内实验中，涂有HPC的p64 FDS似乎具有生物相容性，没有急性炎症。