Cerebral Blood Volume Index Is Associated with Futile Recanalization after Endovascular Thrombectomy in Anterior Circulation Large Vessel Occlusion Stroke.

BACKGROUND AND PURPOSE: Endovascular thrombectomy (EVT) markedly improves outcomes in anterior circulation large vessel occlusion (LVO) stroke. The CBV index, derived from CTP as a marker of collateral circulation, has shown promise for prognosis. Still, its role in predicting futile recanalization remains unclear. This study evaluates the utility of the CBV index for identifying patients at risk of futile recanalization after EVT.

MATERIALS AND METHODS: In this retrospective multicenter study, we assessed patients with anterior circulation LVO involving the intracranial ICA, M1, or proximal M2 segments who underwent EVT. Baseline CTP was used to calculate the CBV index, defined as the ratio of mean CBV in the ischemic region (relative CBF <30% within time-to-maximum >6 seconds) to the contralateral homologous area. Futile recanalization was defined as successful reperfusion (modified TICI ≥2b) with poor functional outcome at 90 days (mRS 3-6). Nonparametric testing, receiver operating characteristic curve analysis, and univariable/multivariable logistic regression were performed.

RESULTS: Among 162 patients, 81 (50%) experienced futile recanalization. CBV index was significantly lower in these patients compared with those with favorable outcomes (0.78 ± 0.16 versus 0.82 ± 0.15; P = .04). Receiver operating characteristic analysis identified a CBV index cutoff of 0.54 for predicting futile recanalization (accuracy 69%). On multivariable analysis, CBV index <0.70 independently predicted futile recanalization (P = .02) after adjustment for clinical and procedural variables.

CONCLUSIONS: Lower CBV index is associated with increased risk of futile recanalization despite successful EVT. CBV index could be used an adjunct imaging biomarker to guide patient treatment planning and predict prognosis.