Abstract 001: Microvascular reperfusion during endovascular therapy: the balance of supply and demand

Abstract

Introduction Endovascular therapy (EVT) has revolutionized acute stroke treatment, but large vessel recanalization does not always result in tissue‐level reperfusion. Cerebral blood flow (CBF) is not routinely monitored during EVT. Here we aimed to leverage diffuse correlation spectroscopy (DCS), a novel transcranial optical imaging technique, to assess the relationship between microvascular CBF and post‐EVT outcomes. Methods Frontal lobe CBF was monitored by DCS in 40 patients undergoing EVT. Baseline CBF deficit was calculated as the percentage of CBF impairment on pre‐EVT CT perfusion. Microvascular reperfusion was calculated as the percentage increase in DCS‐derived CBF that occurred with recanalization. The adequacy of reperfusion was defined by persistent CBF deficit, calculated as: baseline CBF deficit ‐ microvascular reperfusion. Good functional outcome was defined as 90‐day modified Rankin Scale ≤2. Results 36 (of 40) patients achieved successful recanalization, in whom microvascular reperfusion in itself was not associated with infarct volume or functional outcome. However, patients with good functional outcomes had a smaller persistent CBF deficit (median: 1%; IQR: ‐11%–16%) than patients with poor outcomes (median: 28%; IQR: 2%–50%), p=0.02. Smaller persistent CBF deficit was also associated with smaller infarct volume (p=0.004). Multivariate models confirmed that persistent CBF deficit was independently associated with infarct volume and functional outcome. Conclusion CBF augmentation alone does not predict post‐EVT outcomes, but when microvascular reperfusion closely matches the baseline CBF deficit, patients experience favorable clinical and radiographic outcomes. By recognizing inadequate reperfusion, bedside CBF monitoring may provide opportunities to personalize post‐EVT care aimed at CBF optimization.