Stability of ischemic core volume during the initial hours of acute large vessel ischemic stroke in a subgroup of mechanically revascularized patients.

INTRODUCTION: This study aimed to relate growth of the infarct core with time to recanalization in patients receiving mechanical recanalization in whom the time of recanalization is known.
METHODS: We analyzed data from patients with anterior circulation acute ischemic stroke who underwent mechanical recanalization. Demographic and angiographic characteristics, initial apparent diffusion coefficient (ADC) infarct volume, time-to-peak defect volume, revascularization grade, 24-48 h nonenhanced computed tomography (CT) infarct volume, symptom onset to recanalization time, diffusion-weighted imaging to recanalization time, and discharge National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores were compared between minimal and substantial infarct growth groups. Substantial infarct growth was defined as an increase of infarct volume >10 cm(3) assessed by subtracting initial ADC infarct core volume from infarct volume at 24-48 h CT.
RESULTS: Of 25 patients, 9 had minimal infarct growth (median 0 cm(3), interquartile range (IQR) -3 to 5 cm(3)) and 16 had substantial infarct growth (median 103 cm(3), IQR 48-132 cm(3)). Patients with minimal infarct growth had a median time from symptom onset to recanalization of 329 min (IQR 314-412 min) and a median time from imaging to recanalization of 231 min (IQR 198-309 min). On univariate analysis, minimal infarct growth was related to male gender (p = 0.04), smaller initial ADC volume (p = 0.04), higher recanalization grade (p < 0.001), and lower discharge NIHSS (p = 0.04) and mRS grades (p = 0.04).
CONCLUSION: There was no or minimal infarct core growth in at least one third of patients despite an exceptionally long median time from magnetic resonance imaging to recanalization of almost 4 h.