Detection of cerebral blood flow and hemoglobin oxygenation using diffuse correlation spectroscopy and frequency-domain near-infrared spectroscopy during carotid endarterectomy

摘要

Carotid endarterectomy (CEA) is a prophylactic operation to remove plaques inside carotid arteries, during which the patients are at high risk, of embolic stroke. CEA is performed at carotid bifurcation, where carotid arteries are cross-clamping in order to isolate from circulation. However, there has been no gold standard for monitoring blood flow during CEA. Here, we aimed to investigate changes in the blood flow index (CBF,) and hemoglobin oxygenation with a combined frequency-domain near-infrared spectroscopy (FDNIRS) and diffuse correlation spectroscopy (DCS) system in patients who underwent CEA. Our results revealed that CBFi and total hemoglobin concentration (HbT) dropped substantially (58±14% and 18± 10%, respectively) when the carotid arteries were cross-clamped. We also found that overshoot in CBF, and HbT was noticeably higher respect to the baseline before clamping (22±43% and 38±23%, respectively). Oxygen saturation at carotid clamping dropped by an average of 8±5% with respect to the pre-clamp baseline. At unclamping, oxygen saturation had an average overshoot of 2±9% with respect to the baseline level. According to our results, FDNIRS-DCS could be a robust tool for observing vascular physiology changes during CEA. Furthermore, as an indicator of cerebral hemodynamic and a proper perioperative blood flow monitoring, FDNIRS-DCS could help mitigate some of the risks and complications that follow CEA procedures.