Timing of Recanalization After Microbubble-Enhanced Intravenous Thrombolysis in Basilar Artery Occlusion

Abstract

Information about early recanalization of basilar artery occlusion after systemic tissue plasminogen activator remains unknown. We aimed to determine the timing of recanalization in basilar artery occlusion treated with systemic thrombolysis, microbubbles, and continuous transcranial Doppler monitoring. We studied 20 patients with <12 hours basilar artery occlusion treated with intravenous tissue plasminogen activator, 2 hours continuous ultrasound, and 3 boluses of microbubbles. Transcranial Doppler assessed recanalization at different time points. Outcome was assessed using the National Institutes of Health Stroke Scale and modified Rankin scale. Patients were considered to be independent if modified Rankin scale score was <3 at 90 days. Median admission National Institutes of Health Stroke Scale was 18.5 (interquartile range 16 to 26.5) and median time to treatment was 180 minutes (range, 80 to 720 minutes). Rate of complete recanalization raised progressively: at 1 hour 10%, at 2 hours 20%, at 6 hours 35%, and at 24 hours 50%. In 10 patients (50%), no recanalization was observed at 24 hours. Median discharge National Institutes of Health Stroke Scale was 14 (interquartile range 1 to 30). Degree of National Institutes of Health Stroke Scale improvement was related to time of recanalization: median discharge National Institutes of Health Stroke Scale--1 for recanalization between 0 and 6 hours, 11 for recanalization between 6 and 24 hours, and 30 if no recanalization occurred (P=0.002). At 3 months, mortality was 35%. Only one patient (10%) who recanalized within 24 hours died as compared with 60% of nonrecanalizers (P=0.029). Rate of independent patients progressively decreased as time to recanalization increased (P=0.006). In acute basilar artery occlusion, endovenous tissue plasminogen activator, microbubbles, and continuous ultrasound leads to early recanalization in a significant number of patients and this is associated with favorable outcome. Immediate intravenous tissue plasminogen activator treatment should be the first therapeutic option in these patients.