Duke University School of Medicine, Durham, NC.
Department of Interventional Radiology, Duke University Medical Center, Durham, NC.
J Vasc Surg. 2021 Jan;73(1):125-131. doi: 10.1016/j.jvs.2020.03.051. Epub 2020 Apr 22.
Transcarotid artery revascularization (TCAR) is a hybrid technique for carotid artery revascularization that relies on proximal carotid occlusion with flow reversal for distal embolic protection. The hemodynamic response of the intracranial circulation to flow reversal is unknown. In addition, the rate and pattern of cerebral embolization during flow reversal has yet to be investigated. The aim of this study was to characterize cerebral hemodynamic and embolization patterns during TCAR.
A single-institution retrospective study of patients with carotid artery stenosis undergoing TCAR with intraoperative transcranial Doppler (TCD) monitoring of the middle cerebral artery (MCA) was performed. Primary outcomes included changes in MCA velocity and MCA embolic signals observed throughout TCAR.
Eleven patients underwent TCAR with TCD monitoring of the ipsilateral MCA. The average MCA velocity at baseline was 50.6 ± 16.4 cm/s. MCA flow decreased significantly upon initiation of flow reversal (50.5 ± 16.4 cm/s vs 19.1 ± 18.4 cm/s; P = .02). The reinitiation of antegrade flow resulted in a significant increase in the number of embolic events compared with baseline (P = .003), and embolic events were observed in two patients during flow reversal.
TCD monitoring of patients undergoing TCAR revealed that the initiation of flow reversal results in a decrement in ipsilateral MCA velocity. Furthermore, embolic events can occur during flow reversal and are significantly associated with the reinitiation of antegrade flow in the internal carotid artery. However, both of these hemodynamic events were well-tolerated in our cohort. These findings suggest that TCAR remains a safe neuroprotective strategy for carotid revascularization.
经颈动脉血管重建术（TCAR）是一种颈动脉血运重建的杂交技术，它依赖于近端颈动脉闭塞和血流反转来实现远端栓塞保护。目前尚不清楚颅内循环对血流反转的血液动力学反应。此外，血流反转过程中脑栓塞的速度和模式尚未得到研究。本研究旨在描述 TCAR 期间的脑血液动力学和栓塞模式。
对行 TCAR 并术中经颅多普勒（TCD）监测大脑中动脉（MCA）的颈动脉狭窄患者进行单中心回顾性研究。主要结局包括在整个 TCAR 过程中观察到的 MCA 速度和 MCA 栓塞信号的变化。
11 例患者接受了 TCAR 治疗，并进行了 TCD 监测同侧 MCA。MCA 速度的基线平均为 50.6±16.4cm/s。在开始进行血流反转时，MCA 血流显著减少（50.5±16.4cm/s 比 19.1±18.4cm/s；P=0.02）。与基线相比，重新开始顺行血流时，栓塞事件的数量显著增加（P=0.003），并且在两名患者中观察到血流反转期间发生栓塞事件。
对行 TCAR 的患者进行 TCD 监测显示，开始血流反转会导致同侧 MCA 速度降低。此外，血流反转期间可能发生栓塞事件，并且与颈内动脉重新开始顺行血流显著相关。然而，我们的队列中很好地耐受了这两种血液动力学事件。这些发现表明 TCAR 仍然是一种安全的神经保护策略，用于颈动脉血运重建。
