TC multimodal como predictor clínico de recanalización fútil en pacientes con ictus isquémico agudo tratados con trombectomía mecánica

Abstract

ABSTRACT Background and Purpose: Acute ischemic stroke is considered today one of the main health problems in the world, causing relevant morbidity and mortality and consuming a lot of money and resources. The main goal of acute stroke treatment is the prompt recanalization of the occluded vessel in order to restore the brain flow and stop the progression of the infarction. This objective can be achieved nowadays through mechanical thrombectomy, a procedure that has shown significant rates of quick recanalization, allowing a broader time window for treatment in some cases. However, a significant percentage of those successfully treated patients do not experience clinical improvement, the so-called "futile recanalization" phenomenon. Multimodal CT has shown to be a helpful tool to detect these patients, through an advanced neuroimaging process that includes the estimation of blood vessels, brain parenchyma and cerebral perfusion. The objective of this study is to identify which multimodal CT parameters can predict futile recanalization. The individual value of each parameter as well as its combination is statistically analyzed in a cohort of acute stroke patients successfully treated with mechanical thrombectomy at our center. Methods: A retrospective review of a cohort of patients with acute ischemic stroke treated with mechanical thrombectomy in Hospital Clínico Universitario Virgen de la Arrixaca of Murcia is performed. All of them had anterior circulation stroke, 2) fully assessable multimodal CT, and 3) successful recanalization. Clinical and epidemiological data including age, gender, cardiovascular risk factors and others were registered and related to neuroimaging studies. Nonenhanced CT, CT angiography source images, cerebral blood volume (CBV), cerebral blood flow (CBF), and mismatch CBV-CBF maps were studied by Alberta Stroke Program Early CT Score (ASPECTS); collaterals on CT angiography were graded as poor or good (?50% or >50% of the middle cerebral artery territory). Futile recanalization was defined as modified Rankin Scale score >2 at 3 months despite successful recanalization. Results: One hundred fifty patients were included and 57% of them had futile recanalization. They had lower ASPECTS on nonenhanced CT, CT angiography source images, CBV, CBF, and mismatch CBV-CBF and presented more frequently poor collaterals (all P<0.001). The optimal cutoff points in the ASPECTS scale for predicting futile recanalization obtained by ROC analysis were: nonenhanced CT ?7, CT angiography source images ?5, CBV ?6, CBF ?2 and mismatch CBV-CBF ?3. In logistic regression multivariate analyses, CT angiography source images ?5 (OR, 5.1; 95% confidence interval, 1.2- 21.9), CBV ?6 (OR, 3.5; 95% confidence interval, 1.2-9.7), and poor collaterals (OR, 8.6; 95% confidence interval, 1.8-41.7) were independent predictors of futile recanalization. A combined score of these 3 parameters added complementary information: 57% of the patients with score-1, 89% with score-2, and 100% with score-3 had futile recanalization. Reclassification analyses indicated that this score improved prediction of futile recanalization. Conclusions: The clinical evolution of patients with acute ischemic stroke successfully treated with mechanical thrombectomy can be predicted through multimodal CT parameters using ASPECTS and collateral estimation. This tool might be useful in the design of future trials and the selection of thrombectomy patients.