New England Center for Stroke Research, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA.
Radiology, Koç University Hospital, Istanbul, Turkey.
J Neurointerv Surg. 2024 Jun 17;16(7):731-736. doi: 10.1136/jnis-2023-020391.
Flow diverters carry the risk of thromboembolic complications (TEC). We tested a coating with covalently bound heparin that activates antithrombin to address TEC by locally downregulating the coagulation cascade. We hypothesized that the neuroimaging evidence of TEC would be reduced by the coating.
16 dogs were implanted with overlapping flow diverters in the basilar artery, separated into two groups: heparin-coated (n=9) and uncoated (n=7). Following implantation, high-frequency optical coherence tomography (HF-OCT) was acquired to quantify acute thrombus (AT) formation on the flow diverters. MRI was performed postoperatively and repeated at 1, 2, 3, 4, and 8 weeks, consisting of T1-weighted imaging, time-0f-flight (ToF), diffusion weighted imaging (DWI), susceptibility weighted imaging (SWI), and fluid attenuated inversion recovery (FLAIR) sequences. Neurological examinations were performed throughout the 8-week duration of the study.
The mean AT volume on coated devices was lower than uncoated (0.014 vs 0.018 mm); however, this was not significant (P=0.3). The mean number of foci of magnetic susceptibility artifacts (MSAs) on SWI was significantly different between the uncoated and coated groups at the 1-week follow-up (P<0.02), and remained statistically different throughout the duration of the study. The AT volume showed a direct linear correlation with the MSA count and 80% of the variance in the MSA could be explained by the AT volume (P<0.001). Pathological analysis showed evidence of ischemic injury at locations of MSA.
Heparin-coated flow diverters significantly reduced the number of new MSAs after 1 week follow-up, showing the potential to reduce TEC.
血流导向装置存在血栓栓塞并发症（TEC）的风险。我们测试了一种带有共价结合肝素的涂层，该涂层通过局部下调凝血级联反应来激活抗凝血酶以解决 TEC 问题。我们假设该涂层会减少 TEC 的神经影像学证据。
16 只狗的基底动脉中植入了重叠的血流导向装置，分为两组：肝素涂层（n=9）和未涂层（n=7）。植入后，使用高频光学相干断层扫描（HF-OCT）定量测量血流导向装置上的急性血栓（AT）形成。术后进行 MRI 检查，并在 1、2、3、4 和 8 周时重复进行，包括 T1 加权成像、时间飞行（ToF）、弥散加权成像（DWI）、磁化率加权成像（SWI）和液体衰减反转恢复（FLAIR）序列。在研究的 8 周期间进行了神经学检查。
涂层装置上的平均 AT 体积低于未涂层装置（0.014 与 0.018 mm）；然而，这并不显著（P=0.3）。SWI 上的磁敏感伪影（MSA）焦点数量在未涂层和涂层组之间在 1 周随访时存在显著差异（P<0.02），并且在整个研究期间仍然存在统计学差异。AT 体积与 MSA 计数呈直接线性相关，MSA 中 80%的方差可由 AT 体积解释（P<0.001）。病理分析显示在 MSA 位置存在缺血性损伤的证据。
肝素涂层血流导向装置在 1 周随访后显著减少了新 MSA 的数量，显示出减少 TEC 的潜力。
