Endovascular therapy for acute non-terminal internal carotid artery occlusions

Acute stroke from non-terminal internal carotid artery (non-T ICA) occlusions presents with variable symptoms. Although collaterals influence stroke severity, their role in non-T ICA occlusions remains unclear. This study evaluated the safety and efficacy of endovascular therapy (EVT) for isolated non-T ICA occlusions and examined the impact of collateral status.

Patients treated with EVT for acute isolated non-T ICA occlusion between August 2015 and February 2023 were retrospectively analyzed. Demographic, clinical, imaging, and interventional data were collected. Regression models assessed associations between collateral status and clinical outcomes, symptomatic intracranial hemorrhage (sICH), and in-hospital mortality.

Fifty-eight patients were included. Median Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and National Institutes of Health Stroke Scale (NIHSS) were 10 (interquartile range [IQR] 8-10) and 13 (IQR 7-18). Successful (modified Thrombolysis in Cerebral Infarction [mTICI] 2b-3) and complete (mTICI 3) reperfusion was achieved in 91% and 85%, respectively. sICH occurred in 5%, and in-hospital mortality was 21%. Excluding patients with pre-stroke disability, 42% achieved modified Rankin Scale (mRS) ≤ 2 at discharge. Good collaterals were associated with higher ASPECTS at discharge (9 vs. 7, p = 0.035) and numerically lower mortality (17% vs. 28%). Complete reperfusion (mTICI 3) was associated with favorable outcomes, with 100% reaching mRS ≤ 2 and ≤ 3 at discharge and 90 days, compared to poorer outcomes after incomplete reperfusion (mTICI 2b/c). Stroke etiology showed no association with collateral status.

EVT for isolated non-T ICA occlusions is technically effective and appears to be reasonably safe, although clinical outcomes remain modest. Collateral quality was associated with imaging outcomes, while complete reperfusion after distal embolization was associated with better clinical recovery. Collateral assessment and careful management of distal emboli may aid treatment decision-making. The clinical effectiveness of EVT in this setting requires confirmation in controlled trials.