Reopening phenomenon in cardioembolic stroke observed by duplex carotid ultrasonography. Case reports

The authors attempted to detect the reopening of an occluded artery within the carotid axis of acute cardioembolic stroke patients noninvasively by using duplex carotid ultrasonography. The timing of reopening as related to hemorrhagic transformation was also studied. For assessing the reopening phenomenon, quantitative measurement of flow velocity in the bilateral common carotid arteries was repeated in 10 patients who also underwent repeated angiography or autopsy. The ratio of the end-diastolic flow velocity (nonaffected/affected) was related to angiographic or autopsy findings. In 17 patients including the 10 cases mentioned, the occurrence of hemorrhagic transformation was related to the timing of reopening. The hemorrhagic infarction in this study was defined to be a hyperdense area in the basal ganglia on computed tomography. A significant decrease in the ratio of the end-diastolic velocity was observed in 6 patients, in whom the repeated angiography demonstrated reopening of the artery. Of the remaining 4 patients not showing a significant change, only 1 patient was found to have reopening. Reopening was detected in 12 of 17 cases. The timing was 2.5 hours after onset in 1, between days 2 and 5 in 6 cases, and after day 6 in 5 cases. Hemorrhagic infarction was found in 5 of the cases with reopening on days 2-5.