Hypoperfusion Profiles in outcome after Endovascular Therapy for Isolated Internal Carotid Artery Occluded Patients

Background: Patients with acute symptomatic isolated internal carotid artery occlusions (iICAO), also known as ICA-I occlusion, frequently presented with minor neurological deficits. However, they remained at risk for subsequent neurological deterioration even after intravenous thrombolysis. The efficacy of endovascular treatment (EVT) in iICAO patients remains uncertain. Recently, some retrospective studies revealed EVT for acute iICAO was safe and might confer potential benefits. Our aim was to identify the hypoperfusion profiles associated with neurological deterioration and functional outcome following EVT in iICAO patients. Methods: We performed a multi-center, real-world cohort study involving acute symptomatic iICAO patients who underwent EVT from August 2018 to February 2024 across 3 stroke centers. Hypoperfusion profiles were assessed using Tmax volumes (>4s, >6s, >8s, and >10s) and Tmax mismatch ratios (>10s/>8s, >10s/>6s, >10s>4s, >8s/>6s, >8s/>4s, and >6s/>4s). Neurological deterioration was defined as an increase of ?4?points in the NIHSS score prior to EVT. Good outcome was defined as modified Rankin Score 0 - 1 at 90 days. Results: A total of 63 patients were included in the final analysis. Multivariable models showed that a lower Tmax ratio of >6s/>4s was an independent predictor for increased risk of neurological deterioration (OR, 0.003; 95% CI: 0.000-0.133; P = 0.003) and was associated with a better outcome following EVT (OR, 0.066; 95% CI: 0.005-0.874; P = 0.039) after adjustment. The optimal threshold for the Tmax >6s/>4s ratio was identified as 0.5. Conclusions: A perfusion defect severity ratio of Tmax >6s/>4s less than 0.5 might indicate the likelihood of neurological deterioration, yet it would be associated with achieving a good outcome following EVT for iICAO patients. The hypoperfusion profile characterized by a Tmax >6s/>4s might be useful to the neurointerventionists for facilitating appropriate patient triage and guiding prognosis for EVT in iICAO patients.