Reperfusion after stroke sonothrombolysis with microbubbles may predict intracranial bleeding

Background: Although ultrasound-activated microbubbles (MB) accelerate clot lysis, MB activation has shown to promote blood barrier disruption and bleeding in animal models. We conducted a case–control study aimed to investigate the risk of hemorrhagic transformation (HT) after MB-enhanced sonothrombolysis in acute stroke. Methods: We evaluated a total of 296 patients with acute stroke treated with IV tissue plasminogen activator (tPA) Results: Recanalization rates were higher in the MB compared with the control group at 1, 2, 6, and 12 hours ( p p = 0.026) and a higher degree of clinical improvement at 24 hours (54.9% vs 31.1%, p = 0.004). Parenchymal hematoma (PH)1–PH2 and symptomatic intracranial hemorrhage rates were similar in both groups. Moreover, the extent of bleeding after MB-enhanced sonothrombolysis was correlated with the time to reperfusion. Early ( 6 hours) or no recanalization was associated with PH1–PH2 in both the MB group ( p = 0.024) and the control group ( p = 0.045). Conclusion: This hypothesis-generating study shows that microbubble administration was associated with early recanalization and a high rate of hemorrhagic transformation but does not seem to increase the risk of symptomatic intracranial hemorrhage. However, definitive conclusions cannot be made based on these data.