ABSTRACT
PURPOSE: To prove the tissue-protecting effect of mechanical recanalization, we assessed the CT perfusion-based tissue outcome ("TO") and correlated this imaging parameter with the 3-month clinical outcome ("CO"). MATERIALS AND METHODS: 159 patients with large intracranial artery occlusions revealing mechanical recanalization were investigated by CCT, CT angiography (CTA) and CT perfusion (CTP) upon admission. For the final infarct volume, native CCT was repeated after 24âh. The "TO" ("percentage mismatch loss" =â%ML) was defined as the difference between initial penumbral tissue on CTP and final infarct volume on follow-up CCT. We monitored the three-month modified Rankin Scale (mRS), age, bleeding occurrence, time to recanalization, TICI score and collateralization grade, infarct growth and final infarct volume. Spearman's correlation and nominal regression analysis were used to evaluate the impact of these parameters on mRS.â RESULTS: Significant correlations were found for %ML and mRS (câ=â0.48, pâ<â0.001), for final infarct volume and mRS (câ=â0.52, pâ<â0.001), for TICI score and mRS (câ=â-â0.35, pâ<â0.001), for initial infarct core and mRS (câ=â0.14, pâ=â0.039) as well as for age and mRS (câ=â0.37, pâ<â0.001). According to the regression analysis, %ML predicted the classification of mRS correctly in 38.5â% of cases. The subclasses mRS 1 and 6 could be predicted by %ML with 86.4â% and 60.9â% reliability, respectively. No correlations were found for time to recanalization and mRS, for collateralization grade and mRS, and for post-interventional bleeding and mRS.â CONCLUSION: Better than the TICI score, CT-based TO predicts the clinical success of mechanical recanalization, showing that not recanalization, but reperfusion should be regarded as a surrogate parameter for stroke therapy. KEY POINTS: â¢â%ML as well as the final infarct volume can make a direct point about the immediate effect of successful mechanical recanalization.â¢âThe clinical outcomes after mechanical recanalization are reliably predicted by %ML, reflecting the benefit of escalation therapy including interventional reopening of parent vessel occlusions.â¢âNot recanalization but rather reperfusion should be regarded as a surrogate parameter for successful stroke therapy.