UC Irvine

Abstract Background Existing neuromonitoring tools lack the capability for continuous, intraoperative assessment of cerebral oxygenation and tissue viability during endovascular thrombectomy (EVT) of large vessel occlusion stroke. Time-domain near-infrared spectroscopy (TD-NIRS), an advanced non-invasive optical technique, may overcome this challenge. However, no study has yet investigated TD-NIRS’ feasibility as an intraoperative neuromonitoring tool during EVT and its capability in predicting post-recanalization infarct. Methods In this prospective observational study, eleven patients with middle cerebral artery or internal carotid artery occlusion were monitored during EVT using TD-NIRS. Absolute concentrations of oxyhemoglobin ([HbO 2 ]), deoxyhemoglobin ([HHb]), total hemoglobin ([tHb]), and tissue oxygen saturation (StO 2 ) on both hemispheres was derived using a scaled Monte Carlo approach. Patients were dichotomized into post-EVT cortical infarct and no infarct, and the Δ[HbO 2 ]/[HHb] pre- vs post-recanalization was assessed. Results Significant differences were observed in pre- vs post-recanalization [HbO 2 ] ( p =0.0068), [HHb] ( p =0.042), and StO 2 ( p =0.0020) on the affected hemisphere. The Δ[HbO 2 ]/[HHb] significantly differed between patients with and without post-EVT infarct ( p =0.0043). Logistic regression ( p =0.0041) and ROC (AUC=0.82) determined that Δ[HbO 2 ]/[HHb] reliably predicts post-EVT cortical infarct. Conclusions These results suggest TD-NIRS as a novel, adjunctive intraoperative neuromonitoring tool during EVT, with potential to predict post-EVT cortical infarct, guiding clinical management before/after thrombectomy. Graphical Abstract