Near-infrared spectroscopy cerebral oximetry as a predictor of neurological intolerance during carotid artery stenting with proximal protection

Abstract Carotid artery stenting (CAS) with proximal protection can expose occlusion intolerance (OI) due to ipsilateral cerebral hemisphere hypoperfusion. Near-infrared spectroscopy (NIRS) cerebral oximetry can monitor regional cerebral oxygenation (rSO 2 ) in the frontal lobes, and is used during CAS to predict cerebral blood flow insufficiency. The aim of this study was to evaluate rSO 2 as a predictor of OI during CAS. We retrospectively examined 146 patients who underwent CAS with proximal protection. An INVOS® NIRS oximeter was used for rSO 2 measurement, which was compared with stump pressure (SP) measured by a guiding catheter during occlusion of the common carotid artery (CCA) and external carotid artery. For the lesion with OI, distal filter protection was combined with proximal protection if possible, and CCA was intermittently occluded during the procedure. Twenty-seven patients (18%) developed OI. The relative decrease in NIRS oximeter saturation (ΔrSO 2 ) on the ipsilateral side was significantly lower in the OI group than in the tolerance group (14 ± 5.1% vs. 3.4 ± 3.5, p  2 of 8% as the cutoff value for predicting OI, sensitivity was 92% and specificity was 89%. SP was significantly lower in the OI group than in the tolerance group (22 ± 13 mmHg vs. 40 ± 22 mmHg, p  2 was more reliable than SP for predicting OI. Distal filter protection should be combined with proximal protection to prevent prolonged neurological symptoms due to OI.