Gabriel Broocks1, Rosalie McDonough2, Lukas Meyer2, Matthias Bechstein2, Helge Kniep Dipl Ing2, Gerhard Schön3, Marie Teresa Nawka2, Jens Fiehler2, Uta Hanning2, Peter Sporns4, Ewgenia Barow5, Jens Minnerup6, Andre Kemmling7,8. 1. Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany g.broocks@uke.de. 2. Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. 3. Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf. 4. Department of Neuroradiology, Universitaetsspital Basel, Basel, Switzerland. 5. Department of Neurology, University Medical Center Hamburg-Eppendorf. 6. Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany. 7. Department of Neuroradiology, University Hospital Schleswig-Holstein, Lübeck, Germany. 8. Department of Neuroradiology, Westpfalzklinikum, Kaiserslautern, Germany.
Abstract
BACKGROUND AND OBJECTIVES: In acute stroke, early ischemic lesion hypodensity in computed tomography (CT) is considered the imaging hallmark of brain infarction, representing a state of irreversible tissue damage with a continual increase of net water uptake. This dogma is however challenged by rare cases of apparently reversed early lesion hypodensity following complete reperfusion. The purpose of this study was to investigate the occurrence of reversible ischemic edema after endovascular treatment. METHODS: 184 acute ischemic anterior circulation stroke patients were included after consecutive screening. Ischemic brain edema was determined using quantitative lesion net water uptake (NWU) in admission-CT and follow-up CT based on CT-densitometry and ΔNWU was calculated as the difference. The association of edema progression to imaging and clinical parameters was investigated. Clinical outcome was assessed using modified Ranking Scale (mRS) scores at day 90. RESULTS: 27/184 patients (14.7%) showed edema arrest and 3 patients (1.6%) exhibited significant edema reversibility. Higher degree of recanalization (odds ratio (OR): 2.96, 95%CI: 1.46-6.01, p<0.01) and shorter time from imaging to recanalization (OR/hour: 0.32, 95%CI: 0.18-0.54, p<0.0001) were significantly associated with edema arrest or reversibility. Clinical outcome was significantly better in patients without edema progression (median mRS 2 versus mRS 5, p=0.004). DISCUSSION: Albeit rare, lesion hypodensity considered to be representative of early infarct in acute stroke CT may be reversible following complete recanalization. Arrest of edema progression of acute brain infarct lesions may occur after successful rapid vessel recanalization, resulting in improved functional outcome. Future research is needed to investigate conditions where early revascularization may halt or even reverse vasogenic edema of ischemic tissue.
BACKGROUND AND OBJECTIVES: In acute stroke, early ischemic lesion hypodensity in computed tomography (CT) is considered the imaging hallmark of brain infarction, representing a state of irreversible tissue damage with a continual increase of net water uptake. This dogma is however challenged by rare cases of apparently reversed early lesion hypodensity following complete reperfusion. The purpose of this study was to investigate the occurrence of reversible ischemic edema after endovascular treatment. METHODS: 184 acute ischemic anterior circulation strokepatients were included after consecutive screening. Ischemic brain edema was determined using quantitative lesion net water uptake (NWU) in admission-CT and follow-up CT based on CT-densitometry and ΔNWU was calculated as the difference. The association of edema progression to imaging and clinical parameters was investigated. Clinical outcome was assessed using modified Ranking Scale (mRS) scores at day 90. RESULTS: 27/184 patients (14.7%) showed edema arrest and 3 patients (1.6%) exhibited significant edema reversibility. Higher degree of recanalization (odds ratio (OR): 2.96, 95%CI: 1.46-6.01, p<0.01) and shorter time from imaging to recanalization (OR/hour: 0.32, 95%CI: 0.18-0.54, p<0.0001) were significantly associated with edema arrest or reversibility. Clinical outcome was significantly better in patients without edema progression (median mRS 2 versus mRS 5, p=0.004). DISCUSSION: Albeit rare, lesion hypodensity considered to be representative of early infarct in acute stroke CT may be reversible following complete recanalization. Arrest of edema progression of acute brain infarct lesions may occur after successful rapid vessel recanalization, resulting in improved functional outcome. Future research is needed to investigate conditions where early revascularization may halt or even reverse vasogenic edema of ischemic tissue.