1Division of Neurosurgery, Department of Surgery, University of Toronto.
2Department of Anatomic Pathology, Sunnybrook Health Sciences Centre, University of Toronto.
J Neurosurg. 2020 Feb 14;134(3):870-877. doi: 10.3171/2019.12.JNS192881. Print 2021 Mar 1.
Although studies have shown that some degree of iatrogenic endothelial injury occurs during endovascular thrombectomy (EVT), the clinical significance of such injury is uncertain. Furthermore, it is likely that iatrogenic effects such as endothelial denudation, intimal dissection, and tunica media edema will have varying clinical implications. The purpose of this study was to assess the feasibility of endovascular optical coherence tomography (OCT) in quantifying vessel injury in real time after EVT, correlate vessel injury with histological findings, and perform imaging at varying time intervals after EVT to assess the impact of prolonged direct exposure of the vessel to the thrombus.
Yorkshire swine weighing 35-40 kg were selected for use as the animal model, with a total of 9 vessels from 3 swine examined. Thrombectomy was performed using a second-generation stent retriever 1, 3, and 6 hours after thrombus deposition. The presence and degree of denudation of the endothelium, detachment and separation of the layers of the tunic media, hemorrhage within the media, dissection of the vessels, and thrombus within the lumina were assessed using OCT images acquired immediately after EVT. Bland-Altman analysis indicated that these OCT findings were correlated with postmortem histological findings.
OCT image acquisition was technically successful in all cases. Endothelial denudation was present in 65% ± 16%, 87% ± 8%, and 93% ± 7% of the vessel surface 1, 3, and 6 hours, respectively, after thrombus deposition and subsequent EVT. Residual intraluminal thrombus was present in vessels at all time intervals despite complete angiographic revascularization. Bland-Altman plots showed good agreement between OCT and histological analysis with respect to the degree of endothelial denudation and elevation, separation of the tunica media, and hemorrhage within the media. OCT appears to be more specific than histological analysis in detecting endothelial elevation.
OCT is a feasible method that can be used to assess vascular injury after EVT with histological accuracy. Varying degrees of vessel injury occur after EVT, and residual luminal thrombus can be present despite complete angiographic revascularization.
尽管已有研究表明，血管内血栓切除术（EVT）过程中会导致一定程度的医源性内皮损伤，但这种损伤的临床意义尚不确定。此外，内皮剥脱、内膜夹层和中膜水肿等医源性影响可能具有不同的临床意义。本研究旨在评估血管内光学相干断层扫描（OCT）实时评估 EVT 后血管损伤的可行性，将血管损伤与组织学发现相关联，并在 EVT 后不同时间点进行成像，以评估血管长时间直接暴露于血栓的影响。
选择体重 35-40kg 的约克夏猪作为动物模型，共检查 3 只猪的 9 个血管。血栓切除术在血栓沉积后 1、3 和 6 小时使用第二代支架取栓器进行。使用 OCT 图像即刻评估 EVT 后内皮的剥脱程度、中膜各层的分离和剥离、中膜内出血、血管夹层和管腔内血栓的存在和程度。Bland-Altman 分析表明，这些 OCT 发现与死后组织学发现相关。
所有病例均成功进行了 OCT 图像采集。血栓沉积及随后的 EVT 后 1、3 和 6 小时，内皮剥脱分别存在于 65%±16%、87%±8%和 93%±7%的血管表面。尽管血管完全再通，但在所有时间点仍存在残留管腔内血栓。Bland-Altman 图显示，OCT 与组织学分析在评估内皮剥脱程度和隆起、中膜分离以及中膜内出血方面具有良好的一致性。OCT 比组织学分析更能特异性地检测到内皮隆起。
OCT 是一种可行的方法，可与组织学分析具有相同的准确性评估 EVT 后的血管损伤。EVT 后会发生不同程度的血管损伤，尽管血管完全再通，但仍可能存在残留管腔内血栓。
