Kaya Kutlu, Zavriyev Alexander I, Orihuela-Espina Felipe, Simon Mirela V, LaMuraglia Glenn M, Pierce Eric T, Franceschini Maria Angela, Sunwoo John
Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Department of Physiology, Faculty of Medicine, Hacettepe University, 06230 Ankara, Turkey.
Brain Sci. 2022 Aug 2;12(8):1025. doi: 10.3390/brainsci12081025.
Objective: This pilot study aims to show the feasibility of noninvasive and real-time cerebral hemodynamic monitoring during carotid endarterectomy (CEA) via diffuse correlation spectroscopy (DCS) and near-infrared spectroscopy (NIRS). Methods: Cerebral blood flow index (CBFi) was measured unilaterally in seven patients and bilaterally in seventeen patients via DCS. In fourteen patients, hemoglobin oxygenation changes were measured bilaterally and simultaneously via NIRS. Cerebral autoregulation (CAR) and cerebrovascular resistance (CVR) were estimated using CBFi and arterial blood pressure data. Further, compensatory responses to the ipsilateral hemisphere were investigated at different contralateral stenosis levels. Results: Clamping of carotid arteries caused a sharp increase of CVR (~70%) and a marked decrease of ipsilateral CBFi (57%). From the initial drop, we observed partial recovery in CBFi, an increase of blood volume, and a reduction in CVR in the ipsilateral hemisphere. There were no significant changes in compensatory responses between different contralateral stenosis levels as CAR was intact in both hemispheres throughout the CEA phase. A comparison between hemispheric CBFi showed lower ipsilateral levels during the CEA and post-CEA phases (p < 0.001, 0.03). Conclusion: DCS alone or combined with NIRS is a useful monitoring technique for real-time assessment of cerebral hemodynamic changes and allows individualized strategies to improve cerebral perfusion during CEA by identifying different hemodynamic metrics.
本初步研究旨在证明通过扩散相关光谱法（DCS）和近红外光谱法（NIRS）在颈动脉内膜切除术（CEA）期间进行无创实时脑血流动力学监测的可行性。方法：通过DCS对7例患者进行单侧脑血流指数（CBFi）测量，对17例患者进行双侧测量。对14例患者通过NIRS同时双侧测量血红蛋白氧合变化。利用CBFi和动脉血压数据估计脑自动调节（CAR）和脑血管阻力（CVR）。此外，研究了在不同对侧狭窄水平下对同侧半球的代偿反应。结果：颈动脉夹闭导致CVR急剧增加（约70%），同侧CBFi显著降低（57%）。从最初的下降开始，我们观察到同侧半球CBFi部分恢复、血容量增加和CVR降低。在整个CEA阶段，由于两个半球的CAR均完好，不同对侧狭窄水平之间的代偿反应无显著变化。半球CBFi的比较显示，在CEA期间和CEA后阶段同侧水平较低（p < 0.001，0.03）。结论：单独使用DCS或与NIRS联合使用是实时评估脑血流动力学变化的有用监测技术，并且通过识别不同的血流动力学指标，能够制定个性化策略以改善CEA期间的脑灌注。
