Posterior Limb of Internal Capsule Infarct Predicts Functional Outcome in Acute Terminal Internal Carotid Artery Occlusion After Thrombectomy.

Purposes: This study investigated the impact of posterior limb of internal capsule (PLIC) infarct on outcomes of acute internal carotid artery (ICA) occlusion after endovascular thrombectomy (EVT) and the diagnostic accuracy of pretreatment noncontrast computerized tomography (NCCT) and computerized tomography angiography (CTA) findings.

Methods: Patients who underwent EVT for acute ICA occlusion between September 2014 and August 2020 were included in the study. The patients were dichotomized as PLIC infarct or spared. The risk factors for PLIC infarct were investigated, and the association between infarct patterns and clinical outcomes were assessed using logistic regression analysis. Pretreatment NCCT and CTA findings, including PLIC hypodensity, choroid plexus enhancement (CPE), and posterior cerebral artery (PCA) flow status, were calculated for diagnosis of PLIC infarct.

Results: Among 72 patients, the mean age was 70.9 years, and the mean stroke scale was 19.4. PLIC infarct was identified in 15 patients (20.8%). PLIC infarct was associated with worse 90-day functional outcome (P = 0.01, shift test). Lack of CPE is the only independent predictor of PLIC infarct (odds ratio: 127.48, P = 0.001). Lack of CPE and impaired PCA flow produce greater diagnostic accuracy for PLIC infarct than does NCCT hypodensity (area under the receiver operating characteristics curve: 0.85 and 0.76, P = 0.0005 and 0.02, respectively).

Conclusions: In acute ICA occlusion, PLIC infarct is an independent risk factor for worse clinical outcome at 90 days. The lack of CPE was associated with PLIC infarct, and pretreatment CTA can be useful for early diagnosis.